The Upper Limb



The Upper Limb


Donald S. Bae

Peter M. Waters



The purpose of this chapter is to discuss the evaluation and treatment of common congenital differences, traumatic and posttraumatic conditions, neuromuscular problems, and growth deformities affecting the upper limb and hand. Each section examines major diagnostic categories and anatomic regions. The reader will find more information regarding upper extremity development (Chapter 33), fractures (Chapter 34), and limb deficiency (Chapter 30) in other chapters of this text. Treatment of any upper limb or hand condition in a child should address issues of function, growth, aesthetics, and the emotional concerns of the child and family. All are important factors in achieving a successful outcome. The pediatric orthopaedist’s goals are to enhance the ability to place the hand in space; to improve deficiencies in grasp, release, or pinch function; to improve skin mobility and sensibility; and to improve the aesthetic appearance of the limb (1). In addition, treatment of physeal abnormalities improves growth-related loss of motion and function and may reduce pain and musculoskeletal deformity (2). Furthermore, extensive time and counseling are important to address the concerns of the child and parents regarding the alteration in self-image that can occur with any hand or upper limb deformity.


CONGENITAL DIFFERENCES


Pathogenesis.

In utero, the arm bud appears 26 days after fertilization and 24 hours before the appearance of the leg bud. Growth proceeds in a proximal-to-distal manner. Development is guided by the apical ectodermal ridge via fibroblast growth factors, inducing the mesoderm to condense and differentiate (3). The zone of polarizing activity guides radioulnar differentiation and development of the limb, mediated by the sonic hedgehog protein and other growth factors. Similarly, the Wnt signaling center influences dorsal-volar development of the hand. The upper limb anlage is initially continuous and extends to a hand paddle by day 31. The digital rays develop by day 36 with fissuring of the hand paddle, initially in the central rays, followed by the border digits. Mesenchymal differentiation also begins in a proximal-to-distal manner with chondrification, enchondral ossification, joint formation, and muscle and vascular development. Both joint formation and digital separation occur via apoptosis, or programmed cell death. The entire process is complete by 8 weeks after fertilization (4). Other major organ systems develop at the same time as the upper limb, which explains the associated cardiac, craniofacial, musculoskeletal, and renal anomalies that can occur with upper limb differences.

Homeobox, or HOX, genes regulate the development of the limb (5). Their genetic expression controls the timing and extent of growth by regulating mesenchymal cells. At present, the understanding of the genetic basis of limb development, and therefore of the occurrence of congenital anomalies, is expanding rapidly (6, 7, 8, 9, 10, 11 and 12). For example, a mutation at the HOXD13 site has been identified as a cause of polysyndactyly (13). A further understanding of the role of genetics in limb development may revolutionize the treatment of congenital deficiencies.

Congenital anomalies occur in approximately 6% to 7% of live births, with 1% being multiple anomalies. It has been estimated that between 1 in 531 and 1 in 626 live births involve upper extremity anomalies (14, 15). Only 1% to 2% of these congenital differences are the result of chromosomal abnormalities.
However, 75% of 233 spontaneous abortions studied were noted to have an abnormal karyotype, with 18% having a morphologic defect and normal karyotype (16). At present, only a small percentage of these are known to be caused by defined genetic events. In most cases, the cause of the congenital difference is unknown, but expanding genetic information provides optimism for increased knowledge in the near future.


Classification.

There is no perfect classification system for congenital differences of the hand and upper limb. The currently accepted classification system for congenital differences was proposed by Swanson (17) and revised by the Congenital Anomalies Committee of the International Federation of Societies for Surgery of the Hand (18, 19). This classification is based on embryologic or developmental failure and defines deficiencies as terminal or intercalary, with a subclassification into longitudinal and transverse deficiencies. The subcategories are as follows: (a) failure of formation of parts, (b) failure of differentiation of parts, (c) duplication, (d) overgrowth, (e) undergrowth, (f) constriction band syndrome, and (g) generalized skeletal abnormalities. However, there have been reports of inconsistencies in classifying congenital anomalies of the upper limb by this system (20). A more descriptive method has been shown to be valid (19, 21).

This chapter focuses on the major anomalies in each classification group but presents them by anatomic region. Caring for the child with congenital differences involves more than surgical skill. From the time at which the diagnosis is made, these children may potentially be viewed by their parents, family, and society as being impaired; if this premise is left unchallenged, these patients may view themselves the same way (22, 23). It is critical that the treating surgeon helps provide the emotional support and caring that allow the parents and the child to appropriately grieve the loss of a normal hand (24). It is helpful to provide them with in-depth knowledge of the cause and treatment options (25). This process starts with the initial clinical consultation and continues throughout the growth and development of the child into an independent, self-reliant adult (26). Support groups are useful for many of these children and their families.

The children who have normal central nervous systems and cognitive abilities will not be impaired. They will merely develop their skills in a “different” way from their peers. They may need the help of skilled and caring parents, siblings, therapists, teachers, coaches, prosthetists, and surgeons in order to achieve their goals and dreams. Being part of helping these children grow into unique and independent adults is exciting and rewarding for the pediatric orthopaedic surgeon.


ENTIRE LIMB INVOLVEMENT


Neuromuscular


Cerebral Palsy.

Cerebral palsy is a nonprogressive disorder of the central nervous system. It occurs in 5 in 1000 live births and may be caused by perinatal anoxia, intraventricular hemorrhage, or congenital cerebral vascular accidents. It occurs most commonly in premature infants weighing <1500 g (27, 28). The resultant hemiplegia or quadriplegia can lead to significant upper extremity deformities and functional deficits. In hemiplegia, these individuals predominantly use the affected extremity as an assist for the unaffected extremity. In the quadriparetic patient, both upper limbs will have deformities and deficits. The quality of use of an affected extremity is dependent on many factors, including the presence of contractures, voluntary motor control, discriminatory sensibility, learning disabilities, and visual deficits (29, 30, 31, 32 and 33). This section focuses on the deformities and deficits relating to elbow flexion, forearm pronation, wrist palmar flexion and ulnar deviation, finger flexion, and thumb-in-palm deformity in these patients.


Upper Limb Contractures.

Elbow flexion contractures are often mild in patients with hemiplegia (34, 35 and 36). Although approximately 50% of patients will have an elbow flexion contracture, most of these contractures are <30 degrees and do not limit function (37, 38). There may be an associated radial head dislocation in a small number of patients, and this should be assessed radiographically before operative intervention (39). Patients with quadriparesis have greater degrees of elbow flexion contracture. However, these contractures rarely affect their ability to use their motorized wheelchairs, computers, or communication boards. In the maximally dependent quadriparetic, contractures may become severe enough to affect hygiene and care. If skin breakdown develops or is imminent, surgery may be indicated.

Nearly three-fourths of patients with hemiplegia develop a forearm pronation contracture (34). The presence of a significant pronation contracture limits the ability to perform bimanual tasks (32, 35, 38). Individuals with contractures >60 degrees will either perform activities with one hand or use the dorsum of the affected hand or forearm to assist the unaffected hand. These individuals may benefit from surgical correction of their pronation deformity in order to improve the assistive function of that extremity. This can often be performed with simultaneous procedures to improve thumb-inpalm, wrist palmar flexion, or digital flexion deformities (40).

Wrist and hand involvement are common in cerebral palsy. Limited motor function occurs with (a) poor release because of wrist and finger flexor spasticity and weak digital extension, (b) inadequate grasp because of wrist palmar flexion spasticity and weak wrist extension, and (c) minimal pinch because of thumb-in-palm deformity. Discriminatory sensibility is deficient in more than 50% of these children (41). Their discriminatory sensibility may improve with hand surgery. Poor voluntary control of the upper extremity limits functional placement of the hand in space (32, 34). In addition, many of these children have visual and cognitive abnormalities that further impair hand use. At best, most patients with spasticity have assistive hand function.

These children generally posture into elbow flexion, forearm pronation, wrist and palmar flexion, thumb-in-palm, and interphalangeal swan-neck deformities. These deformities may result from both neuromuscular spasticity and contractures. Pronation deformity and thumb-in-palm contractures seem to affect function the most (34). The combination of neurologic impairment and disuse affects growth in length and girth of the affected arm and hand (34).







FIGURE 22-1. Data sheet for prospective analysis of hemiplegic function used at Boston Children’s Hospital.

Upper extremity classification systems have been used for assessing function in patients with cerebral palsy (39, 42) (Fig. 22-1) The House classification of function has 9 levels, extending from 0 (does not use) to 8 (complete spontaneous use) (Table 22-1). In this useful scheme, there are four subgroups of patient function: 0 (no use), 1 to 3 (passive assist), 4 to 6 (active assist), and 7 and 8 (spontaneous use). Because spasticity changes with stress, growth, and central nervous system changes, it may be difficult on any one visit to accurately define a patient’s level of function. This system is used with the input of the patient, family, and physical therapist in order to best define a patient’s overall status. It is used for assessing the outcome of treatments (40).

In addition, the Melbourne Assessment of Unilateral Upper Limb Function and the Pediatric Evaluation of Disability Inventory (PEDI) have been validated for upperlimb function assessment in children with cerebral palsy. The Melbourne Assessment of Unilateral Upper Limb Function has very high internal consistency and high inter- and intraobserver reliability, making it a reliable tool in assessing function and outcome of interventions in patients with cerebral palsy (43, 44). More recently, the Shriner’s Hospital Upper Extremity Evaluation (SHUEE) and the Assistive Hand Assessment (AHA) have been validated to characterize upperlimb function and assess outcomes from nonoperative and surgical interventions (45, 46).









TABLE 22-1 House Classification of Upper Extremity and Hand Function for Patients with Cerebral Palsy











































Level


Designation


Activity Level


0


Does not use


Does not use


1


Poor passive assist


Uses as stabilizing weight only


2


Fair passive assist


Can hold on to object placed in hand


3


Good passive assist


Can hold on to object and stabilize it for use by other hand


4


Poor active assist


Can actively grasp object and hold it weakly


5


Fair active assist


Can actively grasp object and stabilize it well


6


Good active assist


Can actively grasp object and manipulate it against other hand


7


Spontaneous use, partial


Can perform bimanual activities easily and occasionally uses the hand spontaneously


8


Spontaneous use, complete


Uses hand completely independently without reference to the other hand



Treatment

Nonoperative Care. In general, nonoperative treatment options include observation of the patient’s growth and development; the use of therapy, including splints; injections, such as phenol or Botox; and performance of surgical reconstruction.

Physical therapy, starting in infancy, is the standard treatment for children with cerebral palsy. The rationale is that, although the central nervous system deficit is static, the peripheral manifestations of spasticity and muscle imbalance are dynamic and may be progressive with growth. By maintaining range of motion with passive therapy, it is hoped that contractures will be prevented (34, 47). In addition, it is hoped that the affected child is capable of learned motor behavior leading to functional improvement over time, developmentally, and through formal therapy (48, 49). At present, formal therapy is used during the period of infancy. This is most intense in the first year of life and progresses to a home program with less formal supervision. In many states, early intervention programs end at 3 years of age. Monitoring of function and range of motion are performed less regularly thereafter, facilitated in many instances through the school system. During growth spurts that increase spasticity and lessen range of motion, or with specific activities that the patient finds difficult to do, formal therapy is often reinitiated, though the therapeutic benefits of such interventions have not been statistically established (34).

In addition to passive range-of-motion and active-use programs, splints are often used. These may be daytime or nighttime splints. As Manske (47) has observed, it is unclear whether they are cost-effective and alter long-term outcome. However, most caretakers use splints in children with developing contractures. Daytime splints are recommended only if they improve function in patients with dynamic contractures.

Recently, there has been increasing enthusiasm for constraint-induced movement therapy (CIMT). Constraint therapy with casting or immobilization of the unaffected limb has been advocated in order to improve the function of the affected limb in children with hemiplegia and prevent “developmental disuse” of the affected hand and limb (50). A single randomized study has shown this to be effective. It has been shown that patients with hemiplegia do not maximally utilize their motor capabilities in the affected limb in functional tasks (51). Constraint therapy may better enable these patients to maximize their motor function in the affected limb, but there are emotional issues that make this treatment difficult for some families and caregivers. In a small cohort of patients with cerebral palsy (52), it has been shown that functional electrical stimulation (FES) is effective in the short term (up to 3 months) in improving hand function, when applied to the extensor muscles of the wrist and hand. Its long-term effectiveness and applicability to all types, degrees, and ages of patients with cerebral palsy is still unclear.

Injection may provide useful information about the outcome of surgical procedures. At present, botulinum toxin A (Botox, Allergan, Irvine, CA) is the most commonly used pharmacologic agent for neuromuscular injection (40, 53), replacing xylocaine (54, 55), and phenol (56, 57). It is used at an initial dose of 1 to 2 U/kg of body weight and should not exceed 6 U/kg/mo. Injections into the pronator teres, flexor carpi ulnaris (FCU), and adductor pollicis are most often performed. Therapy should be performed aggressively to stretch agonistic musculotendinous units and strengthen antagonists. To date, botulinum toxin A has been most effective in patients with high motivation, good motor learning capacity, and no fixed contracture or limiting spasticity (58). Its role in patients with contractures is limited and less effective, although these patients may show the greatest involvement. Its effectiveness in young children has not yet been studied critically (59, 60 and 61). There are several ongoing prospective studies of botulinum toxin A injections in the upper extremity and hand, so more definitive information should soon be available on the indications and effectiveness of its use in all age groups and at all levels of involvement. At this stage, in our institution, we use botulinum toxin A injections in the upper limbs in (a) younger patients with marked spasticity or developing contractures and (b) older patients with limitations, for whom surgery is not indicated. Complications involve the formation of antibodies to Botox that limit further effective injections and leading to deterioration of upper limb function for the first 1 to 3 weeks post injection in some patients.


Operative Care. The broad indications for surgery in patients with cerebral palsy include (a) contractures that cause hygiene and care problems not solved by therapy, splints, or casts; (b) muscle imbalance or contractures that cause functional deficits that may be improved by tendon transfers, musculotendinous lengthening, and/or joint stabilization procedures; and (c) aesthetic concerns (29, 32, 33 and 34, 62). It may be difficult to identify the individual who will have improved function through surgical reconstruction. As Smith so aptly pointed out, careful preoperative assessment is necessary in order to select the appropriate patients and operations (28). Video recordings of activities of daily living and validated multiple-task assessment scales, such as the Jebsen scale, can be helpful in defining functional limitations. Preoperative video assessments using standardized and validated classification systems (e.g., House classification, SHUEE) are reliable and useful for surgical planning (63).

Surgery has been shown to effectively improve the level of function in all forms of cerebral palsy (40, 64, 65). The best candidates are patients with hemiplegia and good voluntary control, sensibility, and motivation. The principle of surgery is to restore muscle imbalance by lengthening or releasing tight, spastic muscles and by augmenting weak, stretched muscles via musculotendinous lengthenings, tendon transfers, and tenodesis procedures. Unstable joints need to be stabilized by capsulodesis or arthrodesis procedures in order to maximize the outcome of tendon reconstruction. Multiple upper extremity rebalancing procedures performed under one anesthesia are preferred. This can also be performed in conjunction with simultaneous lowerextremity procedures. It cannot be stressed enough to the patient and the family that surgery will not achieve a normal hand. Even the best outcome will result in deficiencies of function, aesthetics, and sensibility. However, in properly selected patients, surgery will clearly improve function and result in patient satisfaction (40, 64, 65). This is particularly evident in individuals using the dorsum of the hand or forearm for bimanual tasks or those with considerable thumb-in-palm deformity (64). The goal must be well defined and specific to the peripheral manifestations of the incurable, central nervous system disorder of cerebral palsy.

Mital (36) cited excellent results with surgical release of elbow flexion contractures in patients with hemiplegia. He recommended release of the lacertus fibrosus, Z-lengthening of the biceps tendon, and musculotendinous lengthening of the brachialis. In mild contractures, release of the lacertus fibrosus and musculotendinous lengthening of the brachialis alone may be sufficient.

More extensive elbow contractures are present in severe quadriparetics. The Z-lengthening of the biceps tendon and the release of the brachialis fascia advocated by Mital (36) are not sufficient to obtain adequate release in these patients. In patients with contractures >90 degrees and skin breakdown, extensive release of the muscle origins from the medial and lateral epicondyles, lengthening of biceps and brachialis tendons, and anterior elbow capsule is necessary so as to solve the hygiene and care-related problems that accompany these conditions. The neurovascular bundle becomes the length-limiting factor. Manske (66) has alternatively proposed additional peritendinous adventitial stripping in efforts to ablate the afferent nerve signals causing elbow flexion spasticity.

As cited above, forearm hyperpronation significantly limits hand function (66) in patients with hemiplegia, and is often seen with wrist and finger flexion deformities. The flexor carpi ulnaris (FCU) is usually the major deforming force at the wrist. Transfer of the FCU to the wrist extensors alleviates the deformity and improves the strength of the antagonist. On occasion, the extensor carpi ulnaris (ECU) is the primary deforming force, as noted by more ulnar deviation than palmar flexion at the wrist. In these situations, the ECU is transferred to the extensor carpi radialis brevis (40). Simultaneous musculotendinous lengthenings of the finger flexors are necessary if the extrinsic finger flexors are tight in the neutral wrist position (33). Otherwise, the patient will develop a disabling clenched fist postoperatively. Z-lengthenings, superficialis-to-profundus flexor tendon transfers, and bony pro cedures are reserved for patients with severe contractures and limited function. In the patient with passive but no active digital extension, the FCU, ECU, or pronator teres (PT) can be transferred into the extensor digitorum communis, with or without additional tendon transfers to the wrist extensors. This will improve both wrist and digital extension.


Transfer of Flexor Carpi Ulnaris for Wrist Flexion Deformity.

Wrist flexion deformity is a frequent problem in children with cerebral palsy (Figs. 22-2, 22-3 and 22-4). There are two aspects to the problem. The first aspect, and the one most often discussed in relation to correction of the deformity, is function. The wrist is often held in flexion, pronation, and ulnar deviation, with the inability to dorsiflex the wrist or to release a grasp.

The second aspect is cosmetic. Most authorities on the subject rarely consider this to be a worthwhile goal of surgery. However, for many patients, especially those with hemiparesis who are attending regular schools, this can be an important consideration.

The criteria for obtaining a good result with this operation were briefly mentioned in the follow-up article on the patients who have undergone this procedure (67, 68), which lists eight prerequisites for this procedure. These requirements are mentioned here as factors to be considered, some more strongly than others, rather than as absolute prerequisites.



  • The flexor carpi ulnaris should have good motor power.


  • There should be good passive dorsiflexion of the wrist, extension of the fingers, and supination of the forearm.


  • The patient should be able to extend the fingers actively, with the wrist held in neutral position.


  • The patient should have good voluntary control over placement of the arm.


  • There should be adequate sensory function in the hand.


  • The patient should have reasonable intellect.


  • The patient should be old enough to comply with the postoperative therapy program.


  • No movement disorder, such as athetosis, should be present.


Transfer of Flexor Carpi Ulnaris for Wrist Flexion Deformity (Figs. 22-2, 22-3 and 22-4)






FIGURE 22-2. Transfer of Flexor Carpi Ulnaris for Wrist Flexion Deformity. Although the procedure is usually performed with the patient in the supine position, the prone position facilitates exposure in the patient with an internal rotation contracture of the shoulder coupled with a pronation contracture of the forearm.

The procedure begins by detaching the flexor carpi ulnaris tendon and by freeing up the muscle belly from its extensive origin along the ulna. Although two separate incisions were made originally, it makes more sense to make one incision because most of the dissection is done in the distal aspect of the forearm. The incision starts distally, at the flexor crease of the wrist and directly over the flexor carpi ulnaris tendon, where it inserts into the pisiform bone. The incision extends about midway up the forearm. A right-angled retractor can be used to elevate the skin at the proximal extent of the wound, allowing dissection to extend proximally as far as the junction of the middle and distal one-third of the forearm. The fascia over the tendon and the lateral aspect of the muscle are divided.

Because the ulnar nerve lies directly under the tendon, caution must be exercised in freeing it from the pisiform bone. After the tendon is divided, the muscle fibers along the lateral aspect of the muscle originating from the ulna are identified easily. These fibers must be freed by dissecting them off the periosteum of the ulna. The flexor carpi ulnaris receives its nerve supply from the underlying ulnar nerve. As the dissection proceeds proximally, it is important to identify and protect these branches. This dissection needs to extend proximally at least to the upper one-third of the forearm—far enough to allow the muscle belly to be directed around the medial border of the ulna in a straight line.






FIGURE 22-3. The second incision is made directly over the extensor carpi radialis and brevis tendons, starting at the extensor crease of the wrist and extending proximally for 3 to 4 cm. After incising the fascia, the two tendons can be identified: the most radial tendon is the extensor carpi radialis longus and the more ulnar one is the brevis. Inserting the transfer into the extensor carpi radialis longus provides a better supination force and is more effective in overcoming ulnar deviation, whereas inserting the transfer into the brevis provides a more central pull. A subcutaneous tunnel is dissected from the proximal extent of the volar incision around the subcutaneous medial border of the ulna. A tendon forceps is used to bring the flexor carpi ulnaris around the medial aspect of the ulna through the subcutaneous tunnel and into the second incision on the dorsal aspect of the wrist. When the surgeon is confident that a sufficient portion of the intermuscular septum has been excised and that the tendon is running along a relatively straight path, the first incision is closed.







FIGURE 22-4. The flexor carpi ulnaris is then sutured into the desired tendon. During this procedure, the wrist is held at about 45 degrees of extension and the forearm is held in maximal supination. After the tendon anastomosis is complete, the wrist should flex passively at least 15 degrees past neutral with the fingers simultaneously going into extension.

The second wound is closed, and the patient is placed in a long arm cast with the wrist in slightly less than maximal dorsiflexion and the forearm in full supination. Because the underlying pathology is spasticity, the thumb should be incorporated in the cast in a position of abduction, with the metacarpal joints flexed about 15 degrees and the interphalangeal joints in neutral position.

Hoffer et al. (69) studied patients with spasticity by using dynamic electromyography and noted that the flexor carpi ulnaris cocontracted with the finger extensors. Because releasing is often more of a problem than grasping, they suggested transferring the flexor carpi ulnaris into the extensor digitorum communis to improve both release of grasp and wrist extension. In a subsequent report, Hoffer et al. (70) demonstrated the effectiveness of this in carefully selected patients and described the indications. In addition to failure in achieving the desired functional goals, the most common complication of this procedure is a wrist extension contracture. Hoffer and colleagues claimed that transferring the flexor carpi ulnaris into the extensor digitorum communis obviates this problem (70).

Thumb-in-palm deformity will limit dynamic pinch and grasp function, and make hygiene difficult to maintain in severe contractures. Static contractures in the web space are corrected with web-space Z-plasties and adductor releases. Hoffer et al. (71) have shown by dynamic electromyography that release of the transverse adductor alone may lead to better pinch postoperatively in selected patients. At times, the static contractures include the flexor pollicis longus and brevis, and these muscles need to be appropriately lengthened or released. Dynamic rebalancing is performed with tendon transfers to the weak abductors and extensors of the thumb. The potential donor muscles used are numerous, and include the palmaris longus, flexor carpi radialis, and brachioradialis, among others. The recipient tendons include the extensor pollices brevis and longus and the abductor pollicis longus. The treatment for each patient should be individualized in order to correct his or her deformity and imbalance. Finally, the metacarpophalangeal (MCP) joint should be stable postoperatively. In most patients, this is achieved by muscle rebalancing. On occasion, a capsulodesis or an arthrodesis procedure should be performed. Selected patients with thumb-in-palm deformity respond very favorably to surgical intervention (64).


Correction of Thumb-in-Palm Deformity in Cerebral Palsy.

Children with cerebral palsy frequently have difficulty with hand function, and often the most noticeable associated deformity is of the thumb (Figs. 22-5, 22-6, 22-7 and 22-8). Several authors have discussed in detail the indications for correction of such deformities (38, 72, 73). Most authors have stressed the importance of the preoperative evaluation of outcome, with assessment of voluntary control, sensation, cognition, and the ability to cooperate with a postoperative program, these being the most important factors to consider in the assessment of outcome.

House et al. (38) have classified the deformities by an assessment of the thumb’s function rather than by its static position.


Type I:

Metacarpal adduction contracture—this is the most common deformity and is usually associated with a contracture of the first thumb web space. It is caused by spasticity and contracture of the adductor pollicis and first dorsal interosseous muscles.


Type II:

Metacarpal adduction contracture and metacarpophalangeal flexion deformity—in this deformity, the interphalangeal joint remains mobile and the metacarpophalangeal joint is fixed in flexion by contracture of the flexor pollicis longus.


Type III:

Metacarpal adduction contracture combined with a metacarpophalangeal hyperextension deformity or instability—this deformity is caused by spasticity of the extensor pollicis longus in the absence of spasticity in the flexor pollicis longus.


Type IV:

Metacarpal adduction contracture combined with metacarpophalangeal and interphalangeal flexion deformities—this is usually caused by spasticity of the flexor pollicis longus and the intrinsic muscles of the thumb, but it may be caused by isolated spasticity of the flexor pollicis longus.

The steps that are taken to correct the deformities are considered in three categories: release of the skin and muscle contractures, augmentation of the weak muscles, and stabilization of joints.

Finally, some patients with cerebral palsy have disabling swan-neck deformities of the interphalangeal joints. If the fingers extend at the proximal interphalangeal (PIP) joint beyond 40 degrees and lock, the position can limit grasp and cause pain. Multiple operations have been advised, including flexor digitorum superficialis tenodesis (33), intrinsic muscle slide (33), lateral band rerouting (74), spiral oblique ligament reconstruction, and resection of the motor branch of the ulnar nerve. The lateral band rerouting procedure provides both intrinsic and extrinsic rebalancing and is effective in correcting the problem (75).

In summary, patients with cerebral palsy who have functionally limiting dynamic spasticity and fixed contractures of the wrist and hand may benefit from surgical reconstruction. Over a 25-year experience, House reported that, for 718 procedures in 134 patients with cerebral palsy, the functional improvement was 2.6 functional levels on the House scale of 0 to 9 (35). Patients with fair and good voluntary control had significantly better improvement in functional use scores than those with poor voluntary control. Often, the more severely involved patients (House levels 0 to 2) respond best to musculotendinous lengthenings, tenodesis, and joint stabilization procedures. More functional patients (House levels 3 to 6) improve with dynamic tendon transfers and releases. Both groups of patients tolerate multiple simultaneous procedures (Fig. 22-9). However, surgery will not create a normal hand. The goals of surgery need to be realistic and attainable. In properly selected patients, surgery will improve assistive function and cosmesis. For many of these children, especially adolescents, and their families, the functional and cosmetic improvements are quite marked and satisfying.


Correction of Thumb-in-Palm Deformity in Cerebral Palsy (Figs. 22-5, 22-6, 22-7 and 22-8)






FIGURE 22-5. Correction of Thumb-in-Palm Deformity in Cerebral Palsy. The release of the contracted first thumb web space is achieved by Z-plasty incision, through which the tight dorsal fascia and the muscles causing the contracture in the first place, the adductor pollicis longus and the first dorsal interosseous muscles, can be divided. The incision is a four-flap Z-plasty. This Z-plasty has been described using angles of 120 and 60 degrees or, as illustrated here, using angles of 90 and 45 degrees. Each limb of the incision should be of equal length. The first limb of the incision is made along the line of the maximal contracture. A: At each end of this incision and at 90 degrees to it, another incision is made. This limb should be equal in length to half the length of the longitudinal limb. Finally, a third limb is added to each end of the incision, which bisects the right angle made by the first two limbs. This should be equal in length to the second limb. B: The incision is closed by transposing the flaps.







FIGURE 22-6. A: After the flaps of the incision are developed and retracted and the dorsal fascia is divided, the tight adductor pollicis and the first dorsal interosseous muscle are identified easily. The origin of the first dorsal interosseous muscle that arises from two heads, one on the first metacarpal and one on the second metacarpal, is released first. Care must be taken as the radial artery passes between these two heads to form the deep palmar arch. The portion inserting on the first metacarpal is released first. B: It usually is necessary to release at least a portion of the head originating on the second metacarpal because the two heads join together close to their origin. After this, the adductor pollicis muscle is released by partially dividing it in its intramuscular portion. This muscle can be found running obliquely beneath the first dorsal interosseous muscle. C: Its division is accomplished more easily, however, from the palmar aspect of the wound. If this does not provide sufficient abduction, it is necessary to release it from its origin on the third metacarpal, as subsequently described.







FIGURE 22-7. In the more severe type II deformities, it is usually necessary to release the origin of the adductor pollicis muscle from the third metacarpal and the origin of the flexor pollicis brevis from the flexor retinaculum. If necessary, a portion of the abductor pollicis brevis can also be released (Ulthoff HK. The Embryology of the Human Locomotor System. Berlin, Germany: Springer-Verlag, 1990.). A palmar incision following the crease of the thenar eminence is used. A: The proximal portion of this incision lies over the third metacarpal. B: After the skin and the fascia are divided, the flexor tendons of the middle finger are retracted in the ulnar direction, whereas the neurovascular bundle and the superficial palmar arch, along with the flexor tendons of the index finger, are retracted in the radial direction. This exposes (distally to proximally) the transverse head of the adductor pollicis, the oblique head of the adductor pollicis, the flexor pollicis brevis, and the abductor pollicis brevis, overlying the opponens pollicis muscle. C: The adductor pollicis muscle is stripped off the third metacarpal, whereas the origin of the flexor pollicis brevis is detached from the flexor retinaculum (transverse carpal ligament).







FIGURE 22-8. In type III deformities, it may be necessary to stabilize the metacarpophalangeal joint of the thumb. This can be done by arthrodesis. In the growing child, the stabilization can be accomplished by denuding the cartilage from the joint surface and by fixing the joint with an intramedullary pin, thereby sparing the growth of the physis.

Another method that preserves more of the function of the thumb, however, is described by Filler and colleagues (Tabin C. The initiation of the limb bud: growth factors, Hox genes, and retinoids. Cell 1995;80:671-674.). Through a V-shaped incision over the volar aspect of the metacarpophalangeal joint, as described for release of trigger thumb, the sheath of the flexor pollicis longus is partially excised to expose the tendon. As with release of trigger thumb, it is important to identify and retract the neurovascular bundles carefully, particularly the radial digital nerve that lies just beneath the skin and crosses the operative site. This exposes the volar plate or capsule. Its proximal insertion (A) is incised and freed. Both sides are then incised just outside of the sesamoid bones so that only the distal attachment remains. The joint is flexed 30 to 35 degrees and transfixed with a small Kirschner wire. The capsule is advanced proximally until it is taut. At this new point of insertion, a small groove is cut into the cortical bone, and a small drill hole is made from this groove to the dorsal surface of the metacarpal. A pull-out wire or a strong absorbable suture is passed through this hole and tied over a button on the dorsum of the thumb (B) to secure the insertion of the volar plate into this groove.

In type IV deformity, it is necessary to lengthen the flexor pollicis longus. AZ lengthening is easily accomplished proximal to the wrist (see Fig. 22-7C).

Numerous muscles can be used to augment the functions of the abductor pollicis longus, the extensor pollicis brevis, or the extensor pollicis longus. The palmaris longus, the brachioradialis, and the flexor carpi radialis muscles are commonly used.







FIGURE 22-9. Clinical photographs of hemiplegic tendon transfers for improving hand and upper limb function. A: Preoperative view of dynamic elbow flexion, forearm pronation, wrist flexion, and ulnar deviation with poor assist function. B: Postoperative active elbow extension with maintenance of active elbow flexion. C: Postoperative active wrist extension with the thumb out of the palm for active pinch. D: Postoperative active grasp function with the thumb abducted and extended actively. (Courtesy of Ann Van Heest, MD.)



Brachial Plexus Birth Palsy.

Brachial plexus birth palsy is rare, with an incidence between 0.1% and 0.4% of live births (76, 77 and 78). Fortunately, most infants with minor birth palsies recover fully. These are the infants who initiate recovery of all muscle groups in the first 1 to 2 months of life. However, permanent impairment does occur in infants who do not initiate antigravity motor recovery before 5 to 6 months of life (79, 80, 81, 82 and 83). Most infants have involvement of the upper trunk (C5-C6, causing Erb palsy and, often, additional involvement of C7). Less often, the entire plexus (C5-T1) is affected. In rare instances, the lower trunk (C7-T1, causing Klumpke palsy) is most affected.

Perinatal risk factors include infants who are large for gestational age; prolonged labor; previous births with brachial plexopathy; difficult delivery, including extraction techniques; and fetal distress. Shoulder dystocia is the mechanical factor that leads to an upper trunk lesion in the difficult vertex delivery. Difficult arm extraction in a breech delivery can result in an avulsion injury of the upper trunk (31). The degree of impairment is related to the level and magnitude of injury to the plexus. Neural injury is defined by the type (stretch, rupture, avulsion) and severity (Sunderland grades I to V). Prognosis
by natural history has been best defined by the spontaneous rate of recovery of muscle strength in the first 3 to 6 months of infancy. Gilbert and Tassin (83) described the recovery of antigravity biceps function in infancy as a predictor of the outcome of spontaneous recovery. This finding was confirmed in a similar study by Waters (82). These studies demonstrated that infants who did not recover biceps function by 3 months of life were not normal after 2 years of age. Gilbert et al. recommend microsurgical reconstruction of the plexus in the first 3 to 6 months of life for infants who fail to recover biceps function (83, 84 and 85)(61). Michelow et al. (86) noted that return of biceps function alone had a 12% error rate in predicting outcome, as defined by long-term antigravity muscle strength. By using elbow flexion, elbow extension, wrist extension, finger extension, and thumb extension (the Toronto scale), their error rate for predicting outcome decreased to 5%. In this system, each muscle group is scored as 0 (no motion), 1 (motion present but limited), or 2 (normal motion), for a maximum score of 12. A score of <3.5 predicted a poor long-term outcome without microsurgery. In all studies, the presence of Horner syndrome, total plexus involvement, and failure of return of function by 3 to 6 months of life portend a poor long-term outcome.

Clinical examination of an infant for motor-sensory function can be challenging. It is important to distinguish true paralysis from the pseudoparalysis that comes with a neonatal clavicle fracture, humeral fracture, or septic shoulder. There can be clinical overlap because fractures also occur in infants with shoulder dystocia and infantile brachial plexopathy. Plain radiographs will identify the infant with clavicle and humeral fractures. In the neonate, these fractures heal within 10 to 21 days. If restriction in range of motion persists after 1 month, there is most likely a concomitant brachial plexopathy. In the rare infant with a septic shoulder, there will be evidence of systemic illness (altered vital signs, change in appetite, toxicity), marked irritability with glenohumeral range of motion, and abnormal white blood cell count (87). If there is doubt, ultrasonography will reveal the effusion, and arthrocentesis will be confirmatory.






FIGURE 22-10. Mallet classification for function about the shoulder in patients with brachial plexus birth palsy. Grade 0 is no function; grade V is normal function; and grades II through IV are depicted for hand-to-mouth, hand-to-neck, external rotation, and hand-to-sacrum activity.

The pupils should be assessed for Horner syndrome. Motor examination is limited to observation of spontaneous activity and stimulated movement by primitive reflexes in the infant. The Moro startle reflex and the asymmetric tonic neck reflex can elicit upper trunk movement in infants in the first 6 months of life. Classification of nerve injury in the ambulatory child has included physical assessment according to the Mallet system. The modified Mallet system classifies uppertrunk function by grading hand-to-mouth, hand-to-neck, and hand-on-spine activity, global abduction, and global external rotation from 0 (no function) to V (normal function). Grades II, III, and IV are illustrated (Fig. 22-10). The Hospital for Sick Children Active Movement Scale is also utilized to define the degree of motor recovery, grades I through IV being gravity-assisted and grades V through VII being against gravity. These classification systems have been shown to be reliable in intra- and interobserver analysis (88).

Radiography can demonstrate an associated fracture of the clavicle or proximal humerus. Radiographic assessment of the severity of brachial plexus injury may be attempted using
myelography, combined computed tomography (CT) scan and myelography, and magnetic resonance imaging (MRI). Kawai et al. (89) compared the results of all three techniques with operative findings. MRI and combined myelography and CT scan were more reliable than myelography alone. The presence of large diverticulae and meningoceles was indicative of root avulsion. Small diverticulae were diagnostic only 60% of the time. Electrodiagnostic studies, with electromyography and nerve conduction studies, are diagnostic of avulsion if there is no reinnervation after 3 months of age. However, the presence of reinnervation does not indicate the long-term quality of muscle recovery.






FIGURE 22-11. Brachialplexus anatomy.


Pathoanatomy.

Understanding the normal anatomy of the brachial plexus is critical to assessing and caring for an infant or a child with brachial plexus palsy (Fig. 22-11). The brachial plexus supplies every muscle of the upper extremity except the trapezius. It is made up of spinal cord nerve root contributions from C5 to T1. Prefixed cords (22% of the specimens) receive a contribution from C4. Postfixed cords are rare (1%) and receive a contribution from T2. The C5 and C6 roots join to form the upper trunk. The C7 root alone becomes the middle trunk. The C8 and T1 roots become the lower trunk. Each trunk has an anterior and a posterior division. The anterior divisions of the upper and middle parts of the trunk form the lateral cord. The posterior divisions of all three parts of the trunk form the posterior cord. The anterior division of the lower trunk continues as the medial cord. The terminal branches of the cords form the major nerves of the upper extremity. The upper and lower subscapular and thoracodorsal nerves branch off from the posterior cord before it bifurcates into the radial and axillary nerves. The medial cord branches are the medial pectoral, medial brachial cutaneous, and medial antebrachial cutaneous nerves, terminating in the medial contribution to the median nerve and the ulnar nerve. The lateral cord supplies the lateral pectoral nerve and the lateral branch of the median nerve, and terminates as the musculocutaneous nerve. In infantile brachial plexopathy, any of these nerves can be affected. However, the most severe injuries are avulsions of the nerve roots. The most common injuries are postganglionic ruptures of the upper trunk.


Treatment


Nonsurgical.

As mentioned above, all infants with brachial plexus birth palsies should be monitored for spontaneous recovery during the first 3 to 6 months of life. During this time, it is important to maintain glenohumeral range of motion, especially passive external rotation (90). This will lessen the risk of progressive glenohumeral dysplasia and dislocation (80, 81 and 82, 90, 91, 92 and 93). Many infants will initiate recovery in the first 6 to 8 weeks of life, and progress to a normal result. Infants who do not demonstrate recovery until after 3 to 6 months of life may be candidates for microsurgery or reconstructive surgery.


Microsurgery.

The optimal timing for microsurgical intervention is still debated. The range used clinically is from 1 month to after 6 months of life (31, 76, 82, 83 and 84). The indications include absence of biceps recovery, Toronto score <3.5, and total plexopathy with Horner syndrome. At present, most centers throughout the world agree that an infant with a flail extremity and Horner syndrome should have microsurgical reconstruction between by 3 months of life. A child with complete absence of upper trunk function (shoulder abduction, elbow flexion)
should have surgery between 3 and 6 months of life. However, the controversy regarding the best timing for microsurgery, whether it should be done at 3, 4, 5, 6, or even 9 months, is still unresolved. This creates difficulties for parents who are trying to do what is best for their infants. There is an ongoing prospective study sponsored by the Pediatric Orthopaedic Society of North America (POSNA) that hopes to resolve this issue.








TABLE 22-2 Computed Tomography/Magnetic Resonance Imaging (CT/MRI) Classification of Glenohumeral Deformity in Chronic Brachial Plexus Birth Palsies





























Type


CT scan/MRI Findings


I


Normal glenohumeral joint


II


Minimal glenoid hypoplasia (>5 degrees increased retroversion)


III


Posterior subluxation of the humeral head


IV


Development of a false glenoid


V


Posterior flattening of the humeral head


VI


Infantile dislocation


VII


Proximal humeral growth arrest


Findings are additive, with increasing severity from type I to type V. From Waters PM, Smith GR, Jaramillo D. Glenohumeral deformity secondary to brachial plexus birth palsy. J Bone Joint Surg Am 1998;80:668-677, with permission.


Microsurgery involves resection of the neuroma and bypass nerve grafting or nerve transfer procedures. On the basis of the information published in peer-reviewed journals, there is no role for neurolysis alone in a patient at any age, especially in the infant older than 6 months of age (94). The recommended surgical technique involves exploration of the brachial plexus and reconstruction of avulsion and nonconducting rupture injuries. If the proximal trunk or nerve roots are intact, sural nerve grafting across the neuroma is preferred. In the presence of an avulsion, intercostal and spinal accessory nerve transfers or distal neurontizations may be performed (95). The surgery will not restore normal function, but there is improvement when compared to natural history outcome alone (82, 83).


Shoulder Surgery.

Children with chronic upper trunk plexopathy may develop external rotation and abduction weakness and internal rotation contractures about the shoulder. This muscle imbalance will progressively alter glenohumeral joint morphology (80, 80) (Table 22-2). Function, especially with the arm in above-horizontal activities, will be impaired (79, 81). These children clearly benefit from surgical intervention (81, 86). In the situation of glenohumeral dislocation in an infant, open reduction and capsulorrhaphy or arthroscopic release and reduction are indicated (96) (Fig. 22-12). Such children have limited external rotation that affects function.

In young children with nearly normal glenohumeral joints (normal or mild increase in glenoid retroversion, grades I and II) or slight posterior subluxation (mild, grade III), anterior musculotendinous lengthening of the pectoralis major and/or subscapularis muscles and posterior latissimus dorsi and teres major transfer to the rotator cuff (92, 97) will improve function (82). In addition, dynamic rebalancing of the muscle forces about the shoulder at a young age has the potential advantages of restoring more normal anatomy and prevent ing progressive glenohumeral joint deformity (98). However, glenohumeral joint remodeling appears to have limited utility with extra-articular musculotendinous rebalancing procedures alone. The benefit of arthroscopic release and reduction, as opposed to open reduction and stabilization, is still unclear in terms of long-term functional outcomes, but both techniques have been shown to be effective in reducing the humeral head and inducing early glenohumeral remodeling, as verified by postoperative MRI (99, 100, 101 and 102). In the older child with more established and progressive deformity of the glenohumeral joint (more severe posterior glenoid flattening, advanced grade III), development of a false glenoid (grade IV) (Fig. 22-13), or humeral head dislocation and deformity (grade V), the deterioration of the joint is usually too advanced to tolerate a soft-tissue procedure. In these situations, humeral derotation osteotomy will improve shoulder function, but will not affect glenohumeral joint morphology (92, 103).

On rare occasions, there are patients who need both osteotomy and tendon transfer. These patients are in the middle range of deformity (grade III). To date, it has been difficult to identify this small subset of patients preoperatively. Therefore, the transfer alone is performed initially, and only if the result is suboptimal more than 1 year later is the secondary-stage osteotomy performed. The role of glenoid osteotomy, its risks, and its benefits are still being defined as it relates to grade III and mild grade IV patients.


Elbow and Forearm Reconstruction.

Elbow flexion and forearm supination deformities can occur with a permanent Klumpke (C8-T1) or a mixed brachial plexus lesion. Contractures, bony deformity, and joint instability are the result of muscle imbalance in a growing child. In the rare case of a patient with residual C8- T1 neuropathy with recovery of C5-C6 function, the elbow and forearm deformities are secondary to an intact biceps muscle in the presence of weak or absent triceps, pronator teres, and pronator quadratus muscles. Progressively, the biceps creates an elbow flexion and supination deformity from unopposed muscular activity. Soft-tissue contractures develop, followed by rotation deformities of the radius and ulna (104). Radial head dislocation may occur (105). The wrist and hand are often in extreme dorsiflexion because of unopposed wrist dorsiflexors. In the position of forearm supination, gravity further exacerbates the dorsiflexion deformity. The patient is left without use of the hand, and performs bimanual activities using the volar and ulnar forearm as an assist. Often, shoulder abduction and internal rotation are required in order to improve assistive function. Activities that require simultaneous elbow flexion and forearm pronation, such as dressing, eating, and writing (106), are significantly limited. In addition, the forearm and hand posture is a major cosmetic concern to both the patient and the family (107).







FIGURE 22-12. Intraoperative shoulder arthroscopy carried out on a patient with brachial plexus type III deformity for reduction of the glenohumeral joint by release of anterior middle and inferior glenohumeral ligaments, subscapularis. A: Illustration of normal arthroscopic anatomy of the shoulder from the posterior portal. (S, subscapularis, anterior capsule and ligaments; B, biceps; HH, humeral head; G, glenoid.) B: View from the posterior portal showing the thickened anterior ligaments and anterior aspect of the deformed glenoid. (*, thickened anterior ligaments capsule and subscapularis; HH, humeral head; B, biceps; G, glenoid.) C: Electrocautery release of the anterior middle and inferior glenohumeral ligaments. A concomitant latissimus dorsi and teres major tendon transfer was performed along with posterior capsulorraphy. (Figures courtesy of Children’s Orthopaedic Surgical Foundation (COSF), © 2010.)

The biceps tendon can be treated by Z-lengthening and rerouting around the radius to convert it from a supinator to a pronator. This will improve elbow extension and forearm pronation. Surgically, the biceps tendon is identified as it inserts into the radial tuberosity. By dissecting lateral to the tendon, the brachial artery and the median nerve are protected. A long Z-plasty of the tendon is performed from the musculotendinous junction to the insertion site. The distal attachment of the tendon is rerouted posteriorly around the radial neck, from medial to lateral. Care must be taken to stay adjacent to the radial neck so as to avoid injury or compression of the radial nerve. The distal tendon is reattached to its proximal counterpart in a lengthened position. This converts the biceps into a forearm pronator (30, 106, 108).

In the presence of a fixed supination contracture, if the rerouting procedure alone is carried out, it will fail because of recurrence of the deformity. Zancolli (106) suggested performing simultaneous interosseous membrane release. However, active pronation was maintained in only 50% of patients who underwent this procedure. Bony correction of the forearm deformity can be performed more predictably. Manske et al. (30) proposed staged procedures of tendon rerouting and forearm osteoclasis. Waters and Simmons (107) described simultaneous tendon rerouting and osteotomy, using internal fixation to avoid multiple operations and loss of alignment. In both
techniques, the forearm is positioned in approximately 20 to 30 degrees of pronation. Others have described corrective osteotomies of the radius and ulna with plate fixation with good reported correction (109).






FIGURE 22-13. A: Schematic showing the method of measuring the glenoscapular angle (glenoid vision) and the percentage of posterior subluxation of the humeral head. To measure the glenoscapular angle, a line is drawn parallel to the scapula and a second line is drawn tangential to the joint. The second line connects the anterior and posterior margins of the glenoid. The cartilaginous margins are used on magnetic resonance images. The osseous margins are used on computed tomographic scans. The intersecting line connects the center point of the first line (approximately the middle of the glenoid fossa) and the medial aspect of the scapula. The angle in the posterior medial quadrant is measured with a goniometer (arrow), and 90 degrees is then subtracted from this measurement to determine the glenoid version. The percentage of posterior subluxation is measured by defining the percentage of the humeral head that is anterior to the same scapular line. The greatest circumference of the head is measured as the distance from the scapular line to the anterior portion of the head. This ratio [the distance to the anterior aspect of the humeral head (AB) divided by the circumference of the humeral head (AC), multiplied by 100] is the percentage of subluxation. B: Magnetic resonance imaging of a type IV deformity with posterior humeral head subluxation and the development of a false glenoid. The glenoid is markedly retroverted. The contralateral glenohumeral joint is normal for age. (Figure courtesy of Children’s Orthopaedic Surgical Foundation (COSF), © 2010.)

These patients clearly have significant improvement in their functional capabilities. Bimanual tasks, such as lifting, carrying, and transferring, are easier. The affected extremity becomes a better assistive extremity to the unaffected side. The wrist and hand now have greater assisted palmar flexion and resolution of their dorsiflexion deformity. In addition, the patients are usually pleased with the aesthetic results.


Arthrogryposis.

Arthrogryposis multiplex congenita is a syndrome of unknown cause that presents at birth characterized by congenital joint contractures and muscle weakness (110). The incidence is approximately 1 in 3000 live births (111). The clinical syndrome is variable and includes classic arthrogryposis (amyoplasia), distal arthrogryposis, and syndromic involvement (112). The classification of arthrogryposis makes the distinction between myopathic and neurogenic types; however, muscle biopsies and electromyography have not been shown to be helpful in determining the mode of therapy for these children (113). Intelligence is usually average or above average. Sensibility is normal. Upper extremity involvement is frequent, with 72% of the 114 patients in the Gibson and Urs study being affected (114). The wrist was most commonly involved, followed by the hand, elbow, and shoulder. In the classic presentation, the elbow is usually contracted in extension at birth. The shoulder is internally rotated with the forearm pronated. Often, there is wrist palmar flexion and ulnar deviation, and the fingers have flexion deformities. The thumb is usually adducted and flexed in the palm (114, 115 and 116). These children often have incomplete syndactylies of all web spaces. The first web-space contracture is usually the most functionally significant. There is usually marked intrinsic muscle weakness. There may be camptodactyly or symphalangism of the
PIP joints. All of this will limit hand function in these children (117).

Involvement is generally bilateral. The absence of both passive and active elbow flexion is a significant functional liability in these children. The goal of orthopaedic management of the arthrogrypotic elbow is to improve self-feeding and independent hygiene skills by achieving both passive and active elbow flexion. The goal of treatment of the hand and wrist is to improve pinch, grasp, and release functions.



SHOULDER REGION


Sprengel Deformity.

Children with Sprengel deformity (128) often present with a decreased neck line, limited motion about the shoulder, or both. This is secondary to the embryonic failure of one, or sometimes both, scapulae to descend in utero. The abnormal elevation is in conjunction with hyperplasia and abnormal alignment of the scapula. Most often, the scapula is small and shaped like an equilateral triangle rather than having a long medial border. The scapula in Sprengel deformity usually has abnormal anterior bending of the superior pole into the convexity of the upper thoracic region. There is often limited forward flexion and abduction of the shoulder because of lack of normal scapulothoracic motion and malpositioning of the glenoid. In up to 50% of cases, there may be an associated omovertebral bar, which consists of a fibrous, cartilaginous, or bony connection between the superior medial angle of the scapula and the cervical spine (129). Frequently, there is associated abnormal regional anatomy including scoliosis, spina bifida, clavicular abnormalities, rib anomalies, and Klippel-Feil syndrome, among others (130, 131). Systemic abnormalities include renal and pulmonary disorders. In 10% to 30% of the cases, the condition is bilateral.

A classification by Cavendish (130) grades the severity of deformity in a rudimentary way: grade I is mild, with level glenohumeral joints and no deformity visible when the patient is dressed; grade 2 has level glenohumeral joints, with a lump in the neck region with the patient dressed; grade 3 is a moderate deformity with 2 to 5 cm of shoulder elevation; and grade 4 is severe, with elevation of the scapula to the vicinity of the occiput. The more severe the deformity, the more likely there are to be limitations
of motion and function and associated regional anatomic anomalies. Surgery is indicated in children with severe aesthetic and functional limitations. Surgery does not correct the scapular hypoplasia but is indicated for improving shoulder motion by restoring more normal positioning of the scapula and the glenoid. This often consists of excising any omovertebral connections and surgically derotating and caudally relocating the scapula. Most of the procedures that are described include extraperiosteal resection of the superior pole of the scapula (130, 132). Subperiosteal resection is associated with a high rate of recurrence (133, 134). In addition to functional indications for surgery, most patients and families welcome the improvement in the appearance of the neck line.

In the mild deformities, extraperiosteal excision of the superior pole of the scapula and any omovertebral connections alone may be satisfactory treatment. In the moderate and severe deformities, the scapula is also derotated and moved more distally in order to bring the glenoid into a more vertical orientation. The purpose of surgery is to improve the neck contour along with shoulder motion and function. Indications for functional improvement have been cited for preoperative abduction <110 to 120 degrees (129, 135). Surgery is recommended most often in patients between 3 and 8 years of age (136, 137 and 138). Surgery after 8 years of age is associated with the highest risk of nerve impairment; clavicular osteotomy or morsellization is recommended in the older child in order to lessen the risk of brachial plexus impingement with scapular descent.

Surgical procedures for scapular descent have included the Woodward procedure (139), the Green procedure (140, 141), and a vertical scapular osteotomy (142). The Green procedure involves extraperiosteal detachment of the scapular insertion of the paraspinal muscles, and reattachment after the scapula has been moved distally with traction cables. Wilkinson and Campbell described a vertical scapular osteotomy in conjunction with a clavicular osteotomy in the older child for improving anterior release and scapular relocation and for lessening the risk of neurologic injury. The Woodward procedure moves the scapula distally by detachment and reattachment of the parascapular muscles at their origins on the spinal process. The modified Woodward procedure includes resection of the superior pole of the scapula in conjunction with surgical scapular descent and realignment. The results have been reported to have improved abduction in the range of 40 to 50 degrees (129, 143) and achieved a satisfactory aesthetic result. Hypertrophic scar formation, however, has been cited often as a complication.


Woodward Repair of Sprengel Deformity.

Congenital high scapula, commonly known as Sprengel deformity, is not a common condition. It can be seen in all degrees of severity. As a result of the school-screening programs, we have seen numerous children with minor degrees of scapular elevation and smaller scapulae on one side. Minor degrees of high-riding scapulae need no treatment and are usually not associated with other developmental abnormalities around the shoulder. At the other end of the spectrum is the child diagnosed at birth or shortly thereafter. The physician seeing the infant or the small child should realize that the deformity usually becomes worse with growth. This can be difficult to judge when the child is between 4 and 8 years of age. However, 4 to 8 years is the ideal time for optimal correction. The condition develops during the 9th to 12th weeks of gestation; therefore, other organs, as well as those structures around the shoulder girdle, may be affected. An understanding of the pathologic anatomy is important for the correction of the deformity and for the avoidance of complications. The scapula is shorter in its vertical height than the opposite normal scapula and is more concave anteriorly to fit the convex shape of the superior aspect of the thoracic cage. In addition, the supraspinous portion of the scapula is usually tilted forward and its superior medial portion may be larger. The clavicle may also be higher and shorter, lacking its usual anterior convexity (136). In about one-third of the cases, an omovertebral bone connects the superior medial angle of the scapula to the posterior elements of the fourth and fifth cervical vertebrae. This may actually be bone, cartilage, or fibrous tissue. Finally, the muscles of the shoulder girdle are usually affected, and hypoplasia of the trapezius and rhomboids is the most common problem.

Two operations for the correction of Sprengel deformity have stood the test of time and are the most commonly used. The Green procedure (140, 144, 145 and 146) detaches the muscles from the scapula, whereas the Woodward procedure (139, 147) detaches the origins of the trapezius and rhomboids from the spinous processes (Figs. 22-14, 22-15, 22-16, 22-17, 22-18 and 22-19). We have had experience with both procedures and find the Woodward procedure to be easier (but not easy) and to produce the same results with a shorter period of hospitalization and lower morbidity. Surgery is expected to improve the cosmetic appearance and the function of the shoulder (129, 148).

One of the most important complications is radial nerve palsy resulting from compression of the brachial plexus between the clavicle and the first rib when the scapula is pulled down. This is more common in children aged 7 years or older and is relatively uncommon in children aged 3 to 4 years. Some authorities have advocated division or morcellation of the clavicle to prevent this complication (136, 149). This is an effective measure, but it is important to determine which patients require it because the incidence of radial nerve palsy is low (139, 140, 143, 150), especially in young children. This additional procedure may be reserved for affected children older than 8 years and for those younger children who have an unusually severe deformity. When nerve palsy is noted after the Woodward procedure, division of the clavicle can be done.


Woodward Repair of Sprengel Deformity (Figs. 22-14, 22-15, 22-16, 22-17, 22-18 and 22-19)






FIGURE 22-14. Woodward Repair of Sprengel Deformity. The patient is positioned prone. The arm and the shoulder on the affected side should be draped free. It may be helpful if the entire posterior thorax is in the sterile field so that the level of the opposite scapula can be observed. It is also helpful if the head is positioned as if looking straight ahead. The incision should be in the midline and should extend from the level of the upper cervical spine (C3, C4) to the lower thoracic spine (T9-T10). The incision is deepened through the subcutaneous tissue and is undermined on the affected side. This dissection should be carried far enough laterally to identify the lateral border of the trapezius muscle in the inferior aspect of the wound and the lateral border of the scapula in the midportion and far enough to allow exposure of the medial half of the supraspinous portion of the spine of the scapula in the superior portion.







FIGURE 22-15. Although Woodward described detaching the trapezius and rhomboid muscles by directly detaching their origins from the midline, this is virtually impossible because they blend inseparably with all the other muscles with origins at the midline. First, the lateral border of the trapezius muscle in the inferior aspect of the wound must be identified and, by blunt finger dissection, separated from the well-defined thoracolumbar fascia and the latissimus dorsi muscle, which cover the serratus and erector spinae muscles. The maneuver eases identification of the origin of the trapezius, which can be detached without cutting into the deeper muscle layers. This detachment of the trapezius is begun distally and extends to the level of the fourth cervical vertebra, where it can be cut transversely to complete its release. After the trapezius muscle is detached and reflected laterally, the attachments of the rhomboid muscle to the scapula are identified.

Blunt finger dissection can be used to separate them from the underlying deep fascia, aiding in detaching them from their origins like the trapezius muscle. Although this dissection is straightforward in an adult cadaver, it is much more difficult in a 4-year-old child with hypoplastic muscles and abnormal fibrous bands. Nevertheless, this step is the key to the exposure of the surgical area and the further steps in the procedure.







FIGURE 22-16. With the trapezius muscle retracted laterally (A), the levator scapula muscle can be identified as the structure originating from the superior medial corner of the scapula and running toward the cervical spine. Although it lies in the same plane as the rhomboid muscles, it is difficult to identify as a distinct structure. In about one-third of cases, an omovertebral bone (not illustrated here), consisting of actual bone, cartilage, or dense fibrous tissue, originates from this corner of the scapula, usually lying beneath the levator scapulae muscle. If present, it is rarely connected to the cervical spine by bone and can usually be detached by sharp dissection after the bone has been exposed by extraperiosteal dissection. It is essential to release all structures in this region because they will prevent downward displacement of the scapula. Fibrous bands, as well as the levator scapulae muscle, are most easily isolated and divided at the superior medial border of the scapula. Notice the transverse cervical artery running deep to the levator scapulae muscle. Care should be taken to avoid cutting the artery (B) by inserting a finger behind the muscle before dividing it.







FIGURE 22-17. With the division of the structures originating from the superior medial border of the scapula, it becomes easier to appreciate the contribution that the large anterior-curving, medial supraspinous portion of the scapula makes to the deformity. This portion of the scapula should be exposed extraperiosteally and excised with large bone-cutting forceps. The surgeon should proceed no farther laterally than the scapular notch to avoid causing injury to the suprascapular artery or nerve. With this completed, the scapula can be everted. This usually reveals multiple fibrous adhesions between the scapula and the chest wall. This is especially true in cases with associated anomalies of the chest wall (e.g., missing ribs). These adhesions should be divided. The scapula can be pushed downward and observed for any other tight structures. In severe cases, it may be necessary to divide a portion of the serratus muscle insertion into the scapula.







FIGURE 22-18. The latissimus dorsi muscle is elevated to allow the scapula to be displaced beneath it. The rhomboid and trapezius muscles are pulled downward, displacing the scapula to the desired level. The affected scapula is smaller than normal; therefore, displacing it so that its inferior border is level with the inferior border of the opposite normal scapula results in overdisplacement. Rather, it should be displaced so that the spines of the two scapulae lie on the same level. The suprascapularis and subscapularis muscles can be repaired by suturing them together over the resected area of the superior medial border of the scapula. If the serratus muscles were detached, they can be resutured to the scapula in a more cephalad location. The rhomboid and trapezius muscles are reattached to their midline origin in a new, more caudal location. Because the most distal origin of the trapezius muscle (extending to T12) was left intact, there is a redundant segment of muscle and fascia distally, which can be excised. If desired, the tip of the scapula can be sutured to an underlying rib by an absorbable suture as a temporary means of fixation. We find this process useful in maintaining proper rotation of the scapula. Finally, the latissimus dorsi muscle is reattached to the tip of the scapula and the wound is closed.







FIGURE 22-19. NH is a 4-year, 8-month-old girl who presented with a high left shoulder and restricted motion, which the parents had observed. They had consulted an orthopaedic surgeon 2 years previously and were told that treatment would not be advisable as she would just be trading a slightly high shoulder for a very large scar. However, the parents were convinced that the deformity was becoming worse. A: A preoperative radiograph shows many of the skeletal anomalies seen in association with the congenital elevation of the scapula. The most obvious is that the scapula is high, but it is also smaller than the opposite scapula. There is a defect in the chest wall, with missing and deformed ribs and mild scoliosis with a vertebral anomaly. B: Postoperatively, the spine of the left scapula is on the same level as in the normal scapula. Its smaller size is obvious and demonstrates that the affected scapula should not be brought so far inferior that the inferior angle is on the same level as the normal scapula.


Repair of Congenital Pseudarthrosis of the Clavicle.

Congenital pseudarthrosis of the clavicle is an unusual condition of unknown etiology. Although the name often causes congenital pseudarthrosis of the clavicle to be confused with congenital pseudarthrosis of the tibia, there is no similarity in the etiology or the natural history of these conditions. The pathology of congenital pseudarthrosis of the clavicle, unlike that of the congenital pseudarthrosis of the tibia, is of two bone ends covered with cartilage and often encapsulated with synovial tissue and fluid. It is clear, however, that resection of the pseudarthrosis, bone graft, and internal fixation are necessary to obtain union (Figs. 22-20, 22-21, 22-22, 22-23 and 22-24) (151, 152, 153 and 154).

Patients may present at any age with a painless lump in the clavicle. Although usually mild in terms of cosmetic deformity and typically asymptomatic in younger children, the deformity worsens with age. Dissatisfaction with the cosmetic appearance usually develops by adolescence, and discomfort, especially with throwing activities, may develop. For these reasons, surgical repair is usually recommended when the condition is noted at a young age. The ideal time to repair the pseudarthrosis is between 3 and 4 years of age to take advantage of remodeling of bone with growth. Repair, however, can be accomplished with improved cosmesis and with elimination of discomfort at any age.


Repair of Congenital Pseudarthrosis of the Clavicle (Figs. 22-20, 22-21, 22-22, 22-23 and 22-24)






FIGURE 22-20. Repair of Congenital Pseudarthrosis of the Clavicle. The patient is placed supine on the operating table with a sandbag under the upper thoracic spine to allow the head and shoulder to fall posteriorly and to improve exposure of the clavicle. The arm, the shoulder, and the clavicle are draped free. The anterior iliac crest is also prepared for the bone graft, which will be necessary in the repair. The skin incision is placed along the cephalad edge of the clavicle. Its length depends on the child’s size, but because the skin in this region is so mobile, it does not have to be excessively long.






FIGURE 22-21. After dividing the skin, the periosteal surface of the clavicle is exposed below the platysma muscle. The normal clavicle and the maximum possible extent of the bulbous ends of the pseudarthrosis should be exposed subperiosteally. In older children, the bulbous ends may be large, in which case it is impossible to remain subperiosteal. The surgeon must be careful during the dissection because of the proximity of the subclavian artery and vein and the apex of the pleural cavity. The pseudarthrosis is then excised with a rongeur. If the surgeon wishes to preserve the entire pseudarthrosis for histology, a Gigli saw or bone biter can be used, provided that the circumferential dissection is sufficient.






FIGURE 22-22. After resection of the pseudarthrosis, a bone graft may be necessary both to secure osteosynthesis and to maintain the length of the clavicle. A full-thickness (tricortical) piece of bone can be harvested from the anterior iliac crest just behind the anterosuperior iliac spine. The portion of bone just beneath the apophysis is thicker than the thin plates of bone that make up most of the iliac wing and provides a better fit with the two ends of the resected pseudarthrosis. A larger piece of bone than is judged necessary should be removed to allow it to be fashioned to the appropriate size and contour.







FIGURE 22-23. Various forms of fixation have been used, all more or less with success. Grogan and colleagues (6) recommend only a suture and no graft. If a graft is used, it is possible to use a Kirschner wire, which is drilled out laterally from the osteotomy site and then through the graft and the proximal fragment. If a Kirschner wire is used, it is necessary to leave the wire outside the skin, bending it at 90 degrees to prevent its migration. It is best to remove this wire within 3 to 4 weeks to prevent infection. Because of the clavicle’s complex shape, it is impossible to keep a pin or wire of any strength within the clavicle’s medullary canal. A thin Kirschner wire that can be passed through the medullary canal of the bone provides little fixation and, unless left outside the skin and bent, risks migration. The use of a pin or wire also risks migration. To avoid these problems, the surgeon can use the small reconstruction plates.

The plates come in two sizes—2.7 mm and 3.5 mm. Their flexibility makes it possible to contour them exactly to the shape of the clavicle and the graft. Because immobilization is required in an active child, regardless of the method of fixation, the plates are sufficiently strong. A,B: With the graft held temporarily in place between the two resected ends of the clavicle by a small Kirschner wire, the appropriately sized reconstruction plate is contoured using the template provided. C: When the proper shape has been achieved, the plate is attached by screws to both ends of the clavicle and the graft. Each end of the clavicle should be fixed with a minimum of two screws, and at least one screw should hold the graft. The wound is irrigated, a small drain is placed adjacent to the clavicle and brought out through the skin lateral to the incision, and the wound is carefully closed in layers. In young children, a Velpeau dressing is applied and reinforced with a roll of plaster if deemed necessary. In older children, who may be more cooperative with the postoperative immobilization, a commercial sling with a strap that passes around the waist to hold the arm next to the trunk is sufficient.







FIGURE 22-24. BC is a 10-year-old boy who noticed a lump on his collar bone and experienced discomfort with throwing activities since an injury 3 years earlier. At the time of the injury he was told that he had fractured his clavicle; at the time of these radiographs he was referred for a persistent nonunion. A: Radiographs demonstrate a typical congenital pseudarthrosis of the right clavicle. B: Results of excision, grafting, and plating are shown. Healing was prompt, and he returned to all activities without discomfort in 6 months.

Several methods of repair have been recommended. Fixation with a Kirschner wire is difficult because of the shape of the clavicle and the potential migration of the wire. However, successful outcome with this technique has been reported (155). This method is less than ideal because the small flexible wire needed to traverse this convoluted shape often breaks. A series of successful cases has been reported using only a suture to secure the bone ends (156). We believe that more rigid fixation is necessary and have used the technique described here with a small reconstruction plate.


ELBOW AND FOREARM REGION


Congenital Dislocations


Congenital Radial Head Dislocations.

Congenital dislocation of the radial head is a rare condition that may not be diagnosed until school age. It is usually an isolated condition, but it may be present in association with other congenital malformations and syndromes, including arthrogryposis and Cornelia de Lange, Larsen, and nail-patella syndromes (123, 157, 158 and 159). It may be associated with radioulnar synostosis (160, 161) or other musculoskeletal anomalies, such as congenital hip dislocation, clubfeet, brachydactyly, clinodactyly, tibial fibular synostosis, congenital below-elbow amputation, and radial or ulnar clubhand. Dislocations associated with Madelung deformity or familial osteochondromatosis (161) may be acquired, and will be considered elsewhere in this chapter.

Congenital radial head dislocation may be bilateral or unilateral (162). It is defined by the direction of subluxation or dislocation. Most congenital dislocations are posterior or posterolateral. It is important to distinguish the congenital dislocation from the posttraumatic dislocation. Because the condition frequently presents late, this distinction can be confusing (162, 157). This is especially true for unilateral anterior dislocations in otherwise healthy children (163, 164, 165 and 166). Radiographic criteria have been established to distinguish this lesion from a chronic, traumatic dislocation. These include a small, domeshaped radial head; a hypoplastic capitellum; ulnar bowing with volar convexity in the anterior dislocation and dorsal convexity in the posterior dislocation; and a longitudinal axis of the radius that does not bisect the capitellum. The presence of these characteristics in the absence of any history of trauma to the affected elbow has been seen as evidence of a congenital radial head dislocation (107, 157, 166, 167, 168, 169, 170 and 171). In addition, bilateral involvement, the presence of other musculoskeletal or systemic malformations, and a positive family history make a congenital cause more likely.


Clinical and Radiographic Features.

Children with radial head dislocations often present after infancy. The most common reasons for presentation are (a) limited elbow extension; (b) posterolateral elbow mass/prominence; and (c) pain with activities, especially athletics (107, 172). Often the diagnosis is made after innocuous trauma based on incidental findings noted on radiographs. The elbow extension loss is frequently <30 degrees and rarely of functional significance. This loss of motion is usually not noted early in life. The mass may be
noted in infancy. Radiocapitellar incongruity can be a cause of pain and disability later in life (162, 172). Unfortunately, many children present late with pain resulting from radiocapitellar articular changes. There is often chronic discomfort with school and sports activities. On occasion, these children may present with an acute loss of motion attributable to a loose osteochondral fragment. Some individuals remain asymptomatic, and the aesthetics of the deformity is their major concern.






FIGURE 22-25. Lateral radiograph of congenital posterolateral dislocation of the radial head. There is evidence of tapering of the radial head and neck posteriorly, bowing of the ulna posteriorly, and a small dome-shaped radial head. These patients often have limited elbow extension and develop intra-articular pain at the abnormal radiocapitellar articulation in adolescence. (Figure courtesy of Children’s Orthopaedic Surgical Foundation (COSF), © 2010.)

On physical examination, the elbow may have cubitus valgus. A flexion contracture of up to 30 degrees often occurs with a posterior subluxation/dislocation. Hyperextension and/or loss of flexion may occur with an anterior dislocation. The radial head is palpable in its dislocated position. A congenital dislocation is not reducible by forceful manipulation, and should not be misinterpreted as a nursemaid’s elbow or a Monteggia lesion. There is usually limited forearm rotation, with supination being affected more than pronation. Clicking and crepitus may be present when there is advanced intra-articular pathology (107).

Radiographs reveal the subluxation/dislocation (Fig. 22-25). The longitudinal axis of the radius does not bisect the capitellum, regardless of the angle of the radiograph. The radius and ulna are of different lengths. The ulna is bowed, with volar convexity in an anterior dislocation and dorsal convexity in the more common posterior dislocation. The capitellum is hypoplastic. The radial head will be convex or dome-shaped, with a long, narrow radial neck.


Natural History.

The presence of a congenital dislocated radial head is not an indication for operative intervention. Many patients with this disorder have no functional limitation and no pain. Their mild limitation of motion may not restrict them in any significant way. The degree of cubitus valgus is usually mild and does not seem to put them at risk for ulnar neuropathy. Therefore, in most cases, a definitive diagnosis followed by observation is most appropriate. If the patient develops pain, functional or progressive limitation of motion, or restriction of elbow-related activities, then surgery may be considered ((107).


Treatment


Operative Care.

Ideally, the care of a congenital dislocated radial head would involve open reduction and restoration of normal anatomy. This has led many surgeons to consider open reduction of a congenital dislocation if the child presents in infancy (123, 160, 166, 173). The logic is that if the radial head can be reduced early in infancy, the deformity of the capitellum and the forearm may not occur or remodel with growth. This may prevent the long-term complications of pain, loss of motion, and osteochondral loose bodies. However, there have been only a small number of published cases of open reduction of congenital radial head dislocations (160, 166, 173, 174). Techniques have included ulnar osteotomy and lengthening, radial shortening and osteotomy, annular ligamentous reconstruction, and the use of limb-lengthening devices to reduce the radial head (170, 173, 175, 176). Sachar and Mih’s report of open reduction through an anconeus approach, followed by annular ligament reconstruction, is the most promising series to date. They described seven cases of open reduction of a congenitally dislocated radial head with good success (173). Their operative findings included an abnormality of the annular ligament that was surgically correctable. The indications for this procedure, and the age limit, are still being defined in this relatively rare condition. It is reasonable in specialized centers to consider open reduction of the congenitally dislocated radial head in the infant younger than 1 to 2 years of age, provided the family is well informed of the limited nature of the information regarding this procedure. Hopefully, clinical surgical research in this area will define the indications and techniques for open reduction and annular ligament reconstruction in congenital radial head dislocations.

Most children with congenital radial head dislocation present later than infancy. Therefore, the most common procedures for this problem are excision of loose bodies and excision of the radial head. The indications for excision of a loose osteochondral fragment are the presence of pain, clicking or locking, and loss of motion. Usually, degenerative changes are too advanced for repair of the osteochondral fragment. There is some controversy regarding the indications and the timing for excision of the radial head. In the skeletally immature patient, the concern is the potential development of postoperative complications (see “Complications,” below). These concerns have not been supported in the published literature on excision of the congenitally dislocated radial head. Most of these children do not present until adolescence with pain or progressive restriction of motion. In our series, the youngest patient with excision of a symptomatic congenital radial head without complication was 8 years of age (162). However, the presence of an
asymptomatic dislocated radial head alone, without painful, progressive restricted range of motion, is not an indication for radial head excision. Indications for radial head excision must include progressive pain, progressive loss of motion, and progressive restriction of activities (174), regardless of age (107).


Complications.

Throughout the 20th century, standard textbooks and journal articles denounced the concept of radial head excision in the skeletally immature individual. Postoperative complications of progressive cubitus valgus and potential associated ulnar neuropathy, proximal migration of the radius with recurrent radiocapitellar impingement, radioulnar synostosis, and reformation of the radial head have been cited (166, 167, 177, 178 and 179). However, most of these problems occurred after radial head excisions to treat trauma. The admonishment never to excise a radial head in a skeletally immature individual still holds true in the posttraumatic situation. These complications are rare after excision for congenital radial head dislocations (160).

“Reformation of the radial head” by bony overgrowth of the proximal neck is the most common problem with excision of a congenital dislocation (178, 180, 181). If it leads to recurrent radiocapitellar impingement, limitation of motion, and/or pain, then repeat bony excision should be performed. Wrist pain does occur in the long term, though most published reports suggest this wrist pain is mild and nonrestrictive (162). Fortunately, iatrogenic radial nerve injury is rare.


Congenital Humeroulnar Dislocations.

Dislocation of the ulnotrochlear joint is exceedingly rare. Mead and Martin described a family with aplasia of the trochlea and humeroulnar dislocations (182). Ulnotrochlear dislocations have also been seen in hyperelasticity syndromes. These situations are rarer than the unusual posttraumatic persistent or recurrent dislocation.

A congenital dislocation will result in limited range of elbow motion that can affect function. The dislocation is usually palpable on examination. There may be axial malalignment, such as cubitus valgus. If severe, the valgus deformity can result in ulnar neuropathy. In recurrent dislocations secondary to hyperelasticity or associated with syndromes such as Rubinstein-Taybi syndrome (183), the elbow instability is palpable and even audible on examination. On occasion, the recurrent instability can lead to osteochondral injury that will cause pain, clicking, or even locking on examination.

Elbow dislocation can also be seen with ulnar dysplasia and ulnar dimelia (184, 185, 186 and 187). The dysplastic ulnotrochlear joint in ulnar dysplasia can lead to elbow problems that limit motion and function. Ulnar dimelia, or mirror hand, is exceedingly rare. The forearm and elbow in this condition consist of two ulnae and no radius. This means that there are two olecranon processes articulating with the distal humerus. There are usually two poorly defined trochleae and no capitellum present. The olecranon processes may face one another. There is significant limitation of elbow and forearm rotation (107, 188, 189).

If the child presents before ossification of the secondary centers, it may be difficult to define the dislocation anatomically by plain radiography. MRI will be diagnostic, but will require sedation or general anesthesia in infants. Ultrasonography may be diagnostic in skilled hands (107).


Natural History.

Children with congenital dislocations will have limited elbow and forearm range of motion and strength, and this will affect function. They must compensate with shoulder, wrist, or trunk range of motion to perform recreational activities and activities of daily living. If left unreduced, chronic arthritic pain could develop. However, this is not well documented.

In children with recurrent instability, pain may develop secondary to osteochondral injury. This can lead to osteochondral loose bodies and arthrosis-like pain.



Congenital Synostoses.

These entities are classified as failure of differentiation of parts with skeletal involvement. In this section, congenital radioulnar and elbow synostoses will be discussed.


Congenital Radioulnar Synostosis.

Congenital synostosis of the proximal radius and ulna is a rare malformation of the upper limb. It is caused by a failure of the radius and ulna to separate, usually proximally.

During the embryonic period of fetal development, the humerus, radius, and ulna are conjoined. Longitudinal segmentation begins distally and proceeds proximally. For a time, the proximal ends are united and share a common perichondrium. Genetic or teratogenic factors that are as yet unknown may disrupt proximal radioulnar joint development, leading to a bony synostosis. This represents a type I deformity. If rudimentary joint development occurs before developmental arrest, a rudimentary radial head will develop with a less severe degree of coalition. This is a type II deformity (190).

During this period of intrauterine development, the forearm is anatomically in a position of pronation (191). Failure of formation of the proximal radioulnar joint at this stage of differentiation will leave the forearm in its fetal position of pronation. With rare exceptions (192), the forearm is fixed in pronation with congenital radioulnar synostosis (191).

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Jul 21, 2016 | Posted by in ORTHOPEDIC | Comments Off on The Upper Limb
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