Hand Fractures
Children are not small adults. Although many similar treatment principles and techniques are used in all age groups, a number of special considerations are required in the treatment of hand fractures in skeletally immature patients. Examination of the injured hand can be challenging, particularly in an anxious or a nonverbal child. An accurate diagnosis is dependent on the clinical history, careful observation, and skilled physical examination. These challenges are compounded by the smaller size of the affected musculoskeletal structures and the abundant surrounding subcutaneous fat and soft tissue. In addition, the smaller size of the underlying skeletal structures necessitates the use of smaller implants placed with precision during surgical procedures. Although the robust healing potential of skeletal injuries in children reduces the risk of delayed union and nonunion compared with their adult counterparts, it also narrows the window of opportunity to correct deformities using closed means. Much of this robust healing potential arises from the thick and biologically active periosteum, which contributes to appositional bone growth, promotes remodeling, and provides a smooth gliding surface for overlying tendons.
The presence of the physis leads to a unique set of treatment considerations. In many situations, an initial bony deformity will remodel with continued skeletal growth. This remodeling potential is dependent on a number of factors, including the magnitude and pattern of bony deformity, proximity of the injury to the adjacent physis, and amount of remaining skeletal growth. In general, the greatest remodeling potential is seen with displacement in the plane of adjacent joint motion, in close proximity to the physis, and in young children with many years of remaining growth. Rotational deformity has little remodeling potential and will persist if not addressed acutely. Similarly, remodeling of radioulnar angulation is limited and is dependent on the amount of adjacent radioulnar joint motion. Efforts to preserve physeal growth may also influence the choice of surgical techniques for operative injuries.
Because children demonstrate varying degrees of compliance following injury or postoperative care, more restrictive immobilization is required to maximize long-term outcomes. Fortunately, the use of longer and more restrictive immobilization following hand fractures in children is not associated with the stiffness seen in adults. Indeed, children are often their own best therapists and quickly resolve issues of stiffness and strength through daily activities of play and sports.
In addition to these considerations, a number of hand injuries are characteristically found in children. Awareness of these injuries and their treatment options is essential for the practicing hand surgeon.
The purpose of this section is to review the epidemiology, pertinent anatomy, and treatment principles for fractures of the child’s hand, with particular emphasis on pediatric injuries requiring surgical care.
Epidemiology
Hand fractures are common in children and adolescents. In their analysis of the 1998 National Hospital Ambulatory Medical Care Survey (NHAMCS), Chung and Spilson reported on the epidemiologic findings of hand and forearm fractures in the United States. Based on their four-stage probability model and subsequent extrapolation of the NHAMCS data, an estimated 1,465,874 patients with hand or forearm fractures present to U.S. emergency departments annually. Phalangeal and metacarpal fractures represented 23% and 18% of these cases, respectively. Interestingly, 15% of all metacarpal fractures and 33% of all phalangeal fractures occurred in patients between 0 and 14 years of age. Furthermore, the highest rate of multiple hand fractures was seen in patients between 0 and 4 years of age (29.8%). The calculated incidence of phalangeal fractures in patients 0 to 4 years old was 207.2 per 100,000. The incidence of metacarpal and phalangeal fractures in patients 5 to 14 years old was 100.0 and 184.9 per 100,000, respectively. Although this analysis was limited by the study design and the nature of the NHAMCS database, the results clearly highlight the frequency with which hand fractures occur in the pediatric population.
Feehan and Sheps performed a population-based study evaluating the epidemiology of hand fractures in British Columbia, Canada, from 1996 to 2001. During the 5-year study period, 72,481 fractures were identified, for an overall annual incidence of 3.63 per 1000 across all age groups. The peak incidence for hand fractures was between 10 and 14 years of age (8.69 per 1000). When divided according to gender, the highest incidence was seen in males between 15 and 19 years of age (12.3 per 1000) and females between 10 and 14 years of age (5.3 per 1000). The authors attributed this peak incidence during adolescence to a combination of accelerated skeletal growth and participation in higher risk sporting and recreational activities.
Over a 6-month period in 2000 at the Pulvertaft Hand Center in Derby, England, 360 children younger than 16 years were seen for hand injuries. Skeletal injuries accounted for 66% of cases, for an annual incidence of 418 per 100,000 children. The peak incidence was in patients between 10 and 16 years of age. Although crushing injuries were the most common mechanism overall, sports-related fractures occurred most commonly in patients older than 10 years. The small finger was most commonly fractured (52%), followed by the thumb (23%). The proximal phalanx was the most frequently injured phalanx (67%). Metacarpal fractures were most commonly diaphyseal, whereas phalangeal fractures typically involved the proximal metaphysis or physis.
Shah and colleagues more recently reported their retrospective analysis of the National Electronic Injury Surveillance System of patients less than 18 years of age treated at U.S. emergency departments from 1990 to 2009. They estimated an incidence of hand injuries at 11.6 per 1000. Approximately one-quarter of all hand injuries consisted of fractures, most commonly affecting patients between 10 and 14 years of age and resulting from recreational and sporting activities.
In addition to the wealth of information on the frequency of hand fractures in children and adolescents, a number of published reports have provided insights into the mechanisms and patterns of injury. Taking these and previous epidemiologic studies together, it is clear that there is a biphasic distribution of hand injuries, with the peak incidences in young toddlers and older adolescents. Bhende and coworkers analyzed 464 children with 477 hand injuries presenting to a level I pediatric emergency department during a 6-month period in 1989. Fractures accounted for 19.3% of all hand injuries, and a bimodal distribution of injuries was seen. Toddlers and younger children presented with lacerations, burns, and fingertip injuries, such as distal phalangeal fractures, as they explored the world around them. Conversely, adolescents tended to present with hand fractures sustained during sporting activities, fights, and self-inflicted trauma. These findings are supported by Liu and associates and Young and colleagues in their separate analyses of children presenting to plastic surgery emergency clinics.
Rajesh and associates similarly attempted to characterize the pattern and nature of pediatric hand fractures in their radiographic review of 280 children treated at the Leicester Royal Infirmary in the United Kingdom. Isolated distal phalangeal tuft fractures were most common in the 0- to 4-year-old age group. Distal phalangeal tuft and shaft fractures were most common in 5- to 8-year-old children. Small finger proximal phalangeal fractures were most common in patients 9 to 12 years of age, and small finger metacarpal neck fractures were seen most often in 13- to 16-year-old adolescents ( Figure 41.1 ). Other published reports have also documented a higher frequency of injury to the border digits and to the small finger in particular.
Approximately one-third of all fractures of the hand propagate through the phalangeal or metacarpal physis. Salter-Harris type II fracture patterns predominate, most commonly of the proximal phalanx. Despite the relative frequency with which physeal fractures occur, posttraumatic physeal arrest is an uncommon sequela in isolated closed injuries.
Preoperative Evaluation
Physical examination of a child’s injured hand can be challenging, particularly in an anxious, noncompliant, or nonverbal patient. Observation and gentle maneuvers are mandatory to obtain the information needed for an accurate and timely diagnosis. The presence of swelling, ecchymosis, guarded active motion, or soft tissue injury can guide the examiner to the region of the pathologic condition.
The tenodesis effect , or gentle pressure applied to the more proximal muscle bellies of the forearm (away from the site of injury), aids in the assessment of both tendon integrity and angular or rotational deformity ( Figure 41.2 ). Assessment of rotational deformity is critical because the deformity exhibits little remodeling and may result in compromised hand function owing to digital overlap or underlap. Malrotation can also be assessed by careful examination of the nail beds of adjacent digits in extension; rotation of greater than 10 degrees out of the plane of adjacent nail plates should alert the examiner to rotational malalignment, although these differences are often subtle and difficult to quantify. Rotational deformity can be better assessed by evaluating digital alignment with attempted finger flexion. In general, the index through small fingers point to the scaphoid tubercle in flexion, roughly in parallel alignment; often, patients normally exhibit some degree of digital underlap, such as small finger beneath ring finger. Comparison to the uninjured contralateral hand is valuable in these situations to determine baseline alignment. In young, anxious, or nonverbal patients who are unable to actively flex their digits during physical examination, the tenodesis effect can be used; gentle passive extension of the wrist also allows obligate digital flexion to assess for rotational alignment. Only after all pertinent information has been derived from observation and indirect examination techniques should direct palpation or stress testing be performed.
Sensibility is difficult to elicit in young patients, and threshold testing or two-point discrimination is generally unreliable until children are older than 8 years. In rare situations in which there is concern about an associated digital nerve injury, warm water immersion can be used. The presence of skin wrinkling after several minutes of water immersion implies innervation.
Thorough and directed radiographic evaluation is imperative in the evaluation of a child’s injured hand. In general, dedicated anteroposterior (AP), lateral, and oblique radiographs of the injured digit are preferred over hand radiographs, in which overlying structures, projection artifacts, and lack of bony magnification can lead to errors in diagnosis. As part of the systematic evaluation of hand radiographs, the phalangeal line test has been proposed as a means of identifying joint malalignment or bony angulation in younger children whose skeletal structures are not yet ossified ( Figure 41.3 ). When expedited or comprehensive radiographic assessment is needed, fluoroscopy or mini-imaging units may assist in obtaining appropriate views of the injured digit, comparison views of the contralateral hand, or dynamic assessment of bony and articular stability. As ultrasonography becomes increasingly ubiquitous, ultrasound imaging may similarly be used to detect subtle or radiographically occult fractures. The normal sequence of skeletal ossification, as well as common normal radiographic variants (discussed later), should be kept in mind to avoid mistaking these for traumatic injuries. Indeed, Chew and Chong previously reported on 204 children referred to a tertiary care center for hand fractures; injuries were misdiagnosed in 16 cases (8%), of which the leading cause was mistaking the epiphyses for fractures.
Among the many proposed classification systems, that of Salter and Harris is most widely used owing to its simplicity and its ability to guide fracture management and prognosticate outcome ( Figure 41.4 ).
Pertinent Anatomy
In the skeletally immature hand, the physes of the phalanges lie perpendicular to the long axis of the bones proximally. The metacarpal physes are distal, with the exception of the thumb metacarpal, which is proximal.
The secondary centers of ossification in the epiphyses appear in a timely and orderly fashion. Although there is variation among individuals, the proximal phalangeal epiphyses become radiographically apparent between 10 and 24 months of age, in females before males. The epiphyses of the middle and distal phalanges ossify approximately 6 to 8 months later. Conversely, physeal closure proceeds in a distal to proximal direction, typically between the ages of 14 and 16 years. The index through small finger metacarpal epiphyses ossify at 12 to 27 months of age and fuse between 14 and 16 years of age. The thumb metacarpal epiphysis, however, does not typically ossify until 24 to 36 months of age.
Common normal radiographic variants include the appearance of a pseudoepiphysis of the distal thumb metacarpal and the proximal index metacarpal. The pseudoepiphyses become radiographically apparent at an early age, do not contribute to the longitudinal growth of the metacarpal, and typically fuse to the metacarpal diaphysis by the seventh year of life. Other anatomic variants include the double epiphysis, most commonly appearing in the index finger and thumb metacarpals. These physeal variants can be misinterpreted as fractures.
As in other long tubular bones that develop via enchondral ossification, the physis of the phalanges and metacarpals is divided into a number of histologic zones. Proceeding from the epiphysis to the metaphysis, the physis contains a resting zone, proliferative zone, zone of hypertrophy, and zone of provisional calcification. Because most physeal fractures propagate through the zone of hypertrophy without disrupting the resting or proliferative zone, posttraumatic growth disturbance is an uncommon sequela of pediatric hand fractures. In the less common circumstance in which the plane of cleavage traverses the zone of proliferation or the resting zone (e.g., Salter-Harris type III, IV, and V fractures), physeal arrest may occur. As the physis becomes more irregular and calcified as patients approach skeletal maturity, Salter-Harris type III and IV injuries are more likely to occur, mimicking more adult fracture patterns (e.g., Bennett fracture at the base of the thumb metacarpal).
Knowledge of the soft tissue anatomy is critical in understanding common fracture patterns and guiding nonoperative as well as surgical treatment. In the interphalangeal joints, the collateral ligaments arise from the collateral recesses of the phalangeal neck proximally and insert to the epiphysis and metaphysis of the adjacent phalangeal base distally. Conversely, at the metacarpophalangeal (MP) joint, the radial collateral ligament arises from the metacarpal epiphysis proximally and inserts on the proximal phalangeal epiphysis distally; the ulnar collateral ligament originates from both the metacarpal epiphysis and metaphysis and inserts on the proximal phalangeal epiphysis. For these reasons, Salter-Harris III fractures are common about the MP joint but rarely involve interphalangeal joints because the epiphysis is “protected” by the collateral ligaments. Conversely, diaphyseal or Salter-Harris II fractures of the distal phalanx or fractures of the proximal phalangeal head or neck more commonly arise from laterally directed forces on the interphalangeal joints.
Understanding of the tendinous insertions in the hand also helps elucidate fracture patterns and guide treatment. The terminal tendon of the long digital extensor inserts onto the dorsal phalangeal epiphysis, and the flexor digitorum profundus insertion to the index through small fingers spans both the volar epiphysis and metaphysis. This anatomic relationship is particularly relevant in the treatment of distal phalangeal physeal fractures, as described later. In the thumb, the extensor pollicis longus inserts onto the dorsal epiphysis of the distal phalanx, the extensor pollicis brevis inserts onto the epiphysis of the proximal phalanx, and the abductor pollicis longus inserts broadly on both the epiphysis and metaphysis of the thumb metacarpal. As in the digits, the flexor pollicis longus inserts on the metadiaphysis of the distal phalanx.
Historical Review
Most hand fractures in children can be managed nonoperatively on an outpatient basis. Indeed, it has been estimated that only 10% to 20% of pediatric hand fractures require surgical care, and these statistics have been corroborated by contemporary published series.
Hastings and Simmons published a retrospective analysis of 354 hand fractures in skeletally immature patients. Border digits were most commonly fractured, and the metacarpal and proximal phalanx were most commonly affected. Although they found a higher prevalence of physeal fractures than had been reported in previous studies, there were only two cases of growth disturbance, seen in patients with severe crush injuries or infection. Overall results were excellent in most cases, but a number of risk factors were associated with fracture malunion and poor results, including failure to obtain adequate radiographs at the time of injury, false assumptions regarding the remodeling potential of phalangeal fractures, and failure to evaluate clinical deformity (i.e., malrotation). Displaced articular fractures, physeal fractures of the distal phalanx, phalangeal neck fractures, and open fractures were identified as carrying a high risk for suboptimal outcomes in the pediatric population ( Box 41.1 ). Given this information, treatment of these fractures is emphasized in the following sections.
Articular fractures, including Salter-Harris type III fractures of the proximal phalanges
Distal phalangeal physeal fractures (Seymour fractures)
Phalangeal neck fractures
Open fractures
Types of Operations
Distal Phalangeal Fractures
Most distal phalangeal fractures are successfully treated without surgery. Recognition of open fractures and subsequent operative treatment lead to a successful result.
Shaft and Tuft Fractures.
Fractures of the distal phalanx typically result from crush injuries in younger patients. In general, patterns of these extraphyseal injuries include transverse, longitudinal split, and comminuted fractures. As expected, these bony injuries are often accompanied by soft tissue avulsions or nail bed lacerations. Treatment is predicated on stabilization of the skeletal injury and appropriate soft tissue injury care, including wound irrigation and débridement, nail plate removal, and nail bed repair. Although the majority of distal phalangeal fractures can be treated effectively with splint or cast immobilization following gentle fracture repositioning, surgical stabilization is occasionally needed for widely displaced injuries. In these situations, a single Kirschner wire placed through the digital tip and across the fracture site will suffice. Some have proposed using a hypodermic needle placed under local anesthesia for fracture stabilization.
Author’s Preferred Method of Treatment
The majority of extraphyseal distal phalangeal fractures are treated with simple splint or cast immobilization for 4 weeks, with excellent healing and outcomes. Rarely, if complete displacement or translation occurs in transverse fracture patterns, Kirschner wire fixation is used to maintain reduction. A single Kirschner wire is passed in a retrograde fashion through the fingertip, across the fracture, and across the distal interphalangeal (DIP) joint, engaging the head of the middle phalanx. The wire is bent and cut outside the skin and is removed in the office after 4 weeks, followed by range-of-motion exercises and a return to activities as symptoms abate.
Physeal Fractures.
Salter-Harris I fractures result in the so-called pseudomallet finger because the distal diaphyseal fragment is volarly displaced, with apex dorsal angulation, by the action of the flexor digitorum profundus. Treatment usually requires extension splinting of the distal phalanx and DIP joint for 4 to 6 weeks.
Seymour fractures are characteristic pediatric injuries of the distal phalangeal physis that merit special attention. Typically resulting from crush injuries to the distal phalanx and DIP joint, these are displaced physeal fractures of the distal phalanx accompanied by an overlying nail bed laceration ( Figure 41.5 ). Often there is interposed soft tissue (i.e., germinal matrix) within the displaced physeal fracture. Technically, this is an open physeal fracture; therefore, treatment should consist of nail plate removal, irrigation, and débridement; liberation of any interposed soft tissue; open reduction of the physeal fracture; and meticulous nail bed repair (see Figure 41.5 ). Dorsal skin incisions from both corners of the dorsal nail fold back toward the DIP joint extension crease elevate the dorsal skin and provide exposure of the germinal matrix and nail bed laceration. The terminal tendon attachment to the dorsal epiphysis must be preserved. Replacement of the trephinated nail plate beneath the dorsal nail fold after nail bed repair often results in sufficient bony stabilization. In cases of excessive instability, transarticular longitudinal pinning of the distal phalanx and DIP joint is used. Krusche-Mandl and colleagues reported results of 24 children treated for Seymour fractures with a mean follow-up of 10 years. With adherence to the above-stated treatment principles, 23 of 24 patients regained full motion, and no infectious complications were noted. Although appropriate and timely treatment results in excellent functional outcomes, failure to attend to these treatment principles and technical steps may lead to late osteomyelitis, physeal arrest, and nail plate deformity ( Figure 41.6 ).
Salter-Harris III fractures of the dorsal base of the distal phalanx represent the pediatric equivalent of the adult mallet finger ( Figure 41.7 ). Fracture displacement is caused by the proximal pull of the terminal tendon on the epiphyseal fracture fragment. Although minimally displaced or nondisplaced fractures can be treated successfully with extension splinting for 4 to 6 weeks, markedly displaced injuries resulting in volar subluxation of the distal phalanx or articular incongruity unamenable to closed reduction merit surgical consideration. Treatment options include formal open reduction and internal fixation via a dorsal approach (with care taken to preserve terminal tendon attachments to the epiphyseal fragment) or closed reduction and transarticular or extension block pinning.
Rarely, injury to the distal phalangeal physis may result in extrusion of the epiphysis, the so-called epiphyseal dislocation ( Figure 41.8 ). In young children in whom the epiphysis is not yet or incompletely ossified, radiographic findings may be very subtle. For this reason, careful correlation between radiographs and clinical examination is necessary. A heightened suspicion for underlying epiphyseal injury is appropriate when there is a “flake,” “crescent,” or poorly defined opacity with irregularity or incongruity of the DIP joint. Because the epiphysis typically displaces dorsally, a true lateral radiograph of the digit is needed for diagnosis.
Author’s Preferred Method of Treatment
Physeal fractures resulting in pseudomallet deformity are treated with closed reduction and immobilization for 4 to 6 weeks. Variations of mallet splinting are viable options in older patients; however, cast immobilization is often needed in the very young to ensure compliance and protection of the injured digit. If an apex dorsal physeal fracture is seen in association with a subungual hematoma, the potential of a Seymour fracture is raised. If there is any question, the nail plate is removed, and appropriate soft tissue repair and bony stabilization are performed, as described earlier. This is particularly true if a persistent widening of the dorsal phalangeal physis is noted after reduction, suggesting soft tissue interposition. Surgical treatment for dorsal Salter-Harris III fractures of the distal phalanx is reserved for patients with greater than 40% articular surface disruption and volar subluxation of the DIP joint, similar to adult bony mallet injuries. Percutaneous pinning techniques are used when adequate closed reduction can be achieved. Otherwise, an open technique to achieve fracture reduction is necessary.
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Most distal phalangeal fractures can be treated nonoperatively with appropriate immobilization and care of associated soft tissue injuries.
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A high index of suspicion is required for Seymour fractures, which should be treated with nail plate removal, fracture débridement and reduction, and nail bed repair.
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Dorsal Salter-Harris III fractures represent the pediatric equivalent of adult bony mallet fractures, with similar treatment principles.
Middle and Proximal Phalangeal Fractures
Fractures of the middle and proximal phalanx are categorized according to their location, pattern, and displacement. Fractures tend to occur at the distal articular surface, diaphysis, physis, or epiphysis. Each has its own set of anatomic and treatment considerations and is discussed separately.
Recognition of and surgery for displaced phalangeal neck and intraarticular fractures reliably result in union and restoration of motion. A delayed presentation complicates surgical management and diminishes outcome.
Articular Fractures of the Phalangeal Head.
Articular fractures of the head of the proximal and middle phalanges include unicondylar, bicondylar, and comminuted fracture patterns. As with adult injuries, treatment is predicated on articular congruity and angular or rotational deformity. Nondisplaced injuries can be treated with cast immobilization. In these situations, however, weekly radiographic examinations should be considered to confirm maintenance of reduction and articular congruity. In fractures with greater than 5 to 10 degrees of angulation or 1 to 2 mm of articular incongruity, surgical intervention is recommended. Closed or open reduction with smooth Kirschner wire or interfragmentary screw fixation is recommended ( ). Although closed reduction is desirable, it is imperative to achieve an anatomic reduction to restore articular congruity. In cases in which closed reduction is not feasible, open reduction is performed via a dorsal approach, allowing visualization of the articular surfaces while carefully preserving the collateral ligament and other soft tissue attachments to the condylar fracture fragments to preserve their vascularity. With careful surgical technique, restoration of motion and preservation of joint stability and articular congruity can be expected. Patients and families should be counseled, however, regarding the potential for long-term stiffness and arthrosis, particularly with severely displaced injuries requiring open treatment.
Author’s Preferred Method of Treatment
For displaced fractures of the phalangeal head, open reduction and internal fixation using smooth pins (or, less commonly, screws) are performed ( Figure 41.9 ). A dorsal curvilinear incision is centered over the affected interphalangeal joint, with the convexity directed to the side of the fracture. Soft tissue flaps are elevated, preserving the dorsal veins and subcutaneous nerves. An incision between the extensor tendon and lateral bands is made, and the overlying extensor apparatus is carefully retracted. The joint capsule is incised to allow visualization of the fracture line and articular surface. Care is taken to preserve soft tissue attachments to the displaced fracture fragments to maintain vascularity and ligamentous stability. Under direct visualization, the fracture is reduced, and restoration of articular congruity is confirmed. Fixation can then be performed with interfragmentary screws or smooth Kirschner wires or a combination thereof. Two screws or pins are used to provide rotational stability and prevent loss of reduction. Intraoperative fluoroscopy confirms reduction, and the pins are left in a percutaneous location to facilitate subsequent removal. The joint capsule, extensor apparatus, and skin are closed in layers, and the patient is placed in a splint or short-arm hand-based cast. Pins are removed after 3 to 4 weeks, after which time range-of-motion exercises are initiated.
Phalangeal Neck Fractures.
Phalangeal neck fractures are characteristic injuries of childhood. They are usually the result of “doorjamb” injuries in which a digit is crushed or trapped in a door and forcefully withdrawn, imparting both extension and rotational forces on the affected digit. Border digits are most commonly affected, and the middle phalanx is injured more frequently than the proximal phalanx. The fracture occurs at the level of the phalangeal neck, and typically the more distal articular segment is displaced into extension, with varying degrees of rotation. Patients present with swelling, tenderness, ecchymosis, and limited interphalangeal joint motion, although the last is often difficult to appreciate in an acutely injured child. A slight angular deformity may be seen.
Careful radiographic evaluation is critical for a timely diagnosis and appropriate treatment. Because the distal fragment typically displaces dorsally, with apex volar angulation, standard AP views of the affected digit often appear benign. A true lateral radiograph of the injured digit is necessary. In addition, in very young patients the phalangeal head remains predominantly cartilaginous, so subtle or seemingly innocuous “bony flecks” should raise the suspicion of a displaced cartilaginous cap or osteochondral fracture. Although the radiographs may appear innocuous, displaced phalangeal neck fractures result in both abnormal digital alignment (in the sagittal plane) and disruption of the normally concave subcondylar fossa. Obliteration of the subcondylar fossa results in a bony block to interphalangeal joint flexion, because the adjacent phalangeal base abuts the bony prominence at the distal end of the proximal fracture fragment.
Al-Qattan’s classification of extraarticular phalangeal neck fractures is clinically useful because it can indicate prognosis and guide treatment. Type I fractures are nondisplaced; type II fractures are partially displaced, with some bony or cortical contact; and type III fractures are completely displaced, without bony apposition. Cast immobilization is sufficient in cases of nondisplaced injuries, although serial radiographs are required to confirm maintenance of reduction. Closed reduction and splinting or cast immobilization are often insufficient for type II and III fractures; therefore, surgical treatment in the form of closed reduction and percutaneous pin fixation is recommended ( Figure 41.10 ). In Al-Qattan’s series of 66 patients with 67 phalangeal neck fractures, 13 fractures were nondisplaced and went on to good to excellent results with nonoperative care. Type II fractures accounted for the majority of injuries, and results were highly dependent on treatment. Patients treated with closed or open reduction and Kirschner wire fixation went on to successful bony healing and good to excellent results. Type II injuries treated with closed reduction without surgical stabilization achieved fair to poor results in 66% of cases. Among the seven type III injuries, failure to perform surgical reduction and Kirschner wire fixation uniformly led to fracture nonunion and poor results. Matzon and Cornwall have proposed a treatment algorithm for the care of acute type II phalangeal neck fractures, beginning with minimally invasive interventions and advancing to more involved techniques as needed. In their series of 61 consecutive children, 49 patients were successfully treated with closed manipulation and percutaneous pin fixation, and 12 underwent percutaneous pin-assisted reduction; no children with acute injuries required open reduction. Overall, the vast majority of patients achieved good to excellent results with low complication rates.
Given the fact that these injuries occur in the phalangeal neck and that the physis is located at the proximal phalangeal metaphysis, remodeling potential is limited. There have been only a handful of reported cases of complete skeletal remodeling of phalangeal neck malunions. Puckett and associates have previously published a retrospective case series of eight children with displaced phalangeal neck fracture malunions followed for a mean of 5 years after injury. In this small series of selected, nonconsecutive patients, sagittal plane angulation improved from 31 to 0 degrees, whereas coronal plane alignment changed from 11 to 4 degrees. Although no patients reported functionally limiting loss of motion, two complained of a persistent aesthetic difference in the coronal plane. Although the authors still support surgical reduction and stabilization for acute displaced phalangeal neck fractures, they believe that children may have some remodeling potential of these injuries.
Review of these case reports leads to a number of observations. First, phalangeal neck remodeling may be expected only in very young patients with a considerable amount of growth remaining. Second, sagittal plane deformity has the greatest remodeling potential; coronal plane angulation or bony malrotation will not improve to the same extent. In addition, although radiographic remodeling may be seen and interphalangeal joint motion improved, in some cases interphalangeal joint flexion is only restored to 80 or 90 degrees. Finally, many reported cases involved the middle phalanx, in which more deformity is tolerated due to the relatively smaller amount of DIP joint flexion needed for composite digital flexion and fist formation. Based on these published reports, observation of displaced phalangeal neck fractures should be considered only if there is no rotational or radioulnar deformity, the adjacent interphalangeal joint is congruently reduced, substantial skeletal growth remains, the resultant loss of interphalangeal joint flexion is tolerable without undue functional compromise, and the patient or family is willing to wait months to years for gradual remodeling.
In cases of displaced phalangeal neck fractures with incipient malunion that present late, percutaneous pin osteoclasis has been advocated as a way to restore bony alignment, improve interphalangeal joint flexion potential, and minimize the risk of osteonecrosis. The most appropriate patients for percutaneous pin osteoclasis are those with persistent tenderness at the fracture site, a fracture line that is still radiographically apparent, and corresponding interphalangeal joint flexion of less than 90 degrees.
In cases of phalangeal neck malunions, there is a great temptation to perform a corrective osteotomy procedure to restore bony alignment and interphalangeal joint motion. Formal open corrective osteotomy carries the risk of osteonecrosis of the phalangeal head in young patients and is not recommended. In cases of long-standing phalangeal neck fracture malunions, subcondylar fossa reconstruction may be considered. Indications include persistent bony malalignment associated with restricted interphalangeal joint motion and functional compromise.
Phalangeal neck fracture nonunions are rare. Patients will present with complaints of instability, deformity, or stiffness. In the absence of osteonecrosis of the small articular fragment, bone grafting and longitudinal Kirschner wire fixation will allow for healing, though often some residual stiffness remains.
Author’s Preferred Method of Treatment
Nondisplaced phalangeal neck fractures can be treated with cast immobilization, but weekly radiographs are required to rule out delayed displacement. In type II or III injuries, closed reduction and percutaneous pinning via cross pins are performed. Patients are casted for 3 to 4 weeks, after which pins are removed and motion is initiated. In the rare situation in which an adequate reduction cannot be obtained with closed techniques, open reduction can be performed via a mid-axial approach, with care taken to preserve the collateral ligament and soft tissue attachments to the articular segment. In fractures with nascent malunion that present late, percutaneous pin osteoclasis is considered if the fracture is still radiographically visible and tenderness to palpation is felt at the fracture site ( Figure 41.11 ). In cases presenting late in which active or passive interphalangeal joint flexion to 90 degrees or more is documented on examination and fluoroscopy, observation is recommended. In established malunions with functionally limiting restrictions in interphalangeal joint flexion, subcondylar fossa reconstruction via a volar or midlateral approach is performed. Rongeurs or burs can be used to remove the bone obliterating the subcondylar fossa. Care must be taken to avoid overzealous resection because the dorsal bony bridge can become quite narrow in cases with considerable dorsal displacement of the articular fragment. Intraoperatively, adequate bony resection is confirmed by passive interphalangeal joint flexion to 90 degrees or more. Early active and passive motion is initiated to maximize the outcome.
Phalangeal Shaft Fractures.
Diaphyseal fractures of the phalanges represent approximately two-thirds of phalangeal injuries. The most common mechanism is combined bending and torsional forces sustained during falls or sporting activities. Proximal phalangeal shaft fractures usually exhibit apex volar angulation owing to the combined forces of the extensor mechanism on the distal fragment and intrinsic musculature on the proximal fragment. Conversely, fractures of the middle phalanx exhibit either apex palmar or dorsal angulation, depending on the location of the fracture in relationship to the flexor digitorum superficialis insertion. Fractures distal to the flexor digitorum superficialis insertion typically angulate in an apex volar manner, with the extensor mechanism pulling the distal fragment dorsally. Although up to 10 degrees of angulation is acceptable, closed reduction is recommended for greater amounts of angulation or any malrotation resulting in digital overlap or underlap (see Figure 41.2 ). Al-Qattan and coworkers previously reported on 92 children studied prospectively with proximal phalangeal base fractures. The authors noted excellent outcomes in patients treated with closed reduction with or without percutaneous pinning for cases with greater than 10 degrees of angulation, whereas remodeling was seen in patients with less than 10 degrees of radiographic angulation.
Following closed reduction and cast immobilization, serial clinical and radiographic evaluations are necessary to ensure maintenance of adequate alignment. In patients with irreducible or unstable fractures, surgical treatment via closed or open reduction and smooth pin fixation are recommended. In cases of long oblique fractures, two or more smooth Kirschner wires placed orthogonally to the fracture plane provide both axial and rotational stability. In transverse fractures, oblique cross-pinning may be used, although care should be taken to avoid crossing pins at the fracture site because this results in suboptimal fixation. The end of the pins are bent and trimmed external to the skin and removed after 4 weeks, followed by motion exercises. Boyer and colleagues previously reported a series of 105 patients treated with percutaneous pinning for displaced proximal phalanx fractures. In this retrospective cohort, 36 had postoperative stiffness and 31 ultimately underwent therapy to restore motion. Despite this high proportion of patients with stiffness in the initial postoperative period, patients with follow-up for longer than 12 months regained full motion and excellent function.
Author’s Preferred Method of Treatment
Closed reduction and cast immobilization are recommended for phalangeal shaft fractures with malrotation or angulation of greater than 10 degrees. Serial radiographs are necessary to confirm maintenance of reduction. Immobilization is discontinued after 3 to 4 weeks, with a gradual return to activity. In cases of fracture instability or inadequate alignment, closed reduction and percutaneous pin fixation are performed ( Figure 41.12 ). Pins are removed at 3 to 4 weeks, followed by range-of-motion exercises. Irreducible fractures require open reduction and pin fixation.
Physeal Fractures.
Physeal fractures of the phalanges are common injuries, secondary to combined bending and rotational moments sustained during falls and sporting activities. Patients and families may express anxiety upon learning of the occurrence of a growth plate fracture; however, multiple studies have demonstrated that one-third of all bony injuries of the growing hand involve the physis, and physeal arrest is uncommon. The proximal phalanx of the small finger is most commonly affected, resulting in the so-called extraoctave fracture ( Figure 41.13 ). The thumb is injured in roughly one-fifth of cases. Physeal fractures of the middle phalanx are considerably less common than those involving the proximal phalanx. Salter-Harris type II patterns predominate owing to the anatomic features of the collateral ligaments described previously.
Closed reduction is recommended for fractures with greater than 10 degrees of angulation and any malrotation, owing to the limited remodeling potential of radioulnar or rotational deformity. During closed reduction maneuvers, flexion of the MP joint assists in stabilizing the proximal fracture fragment by tensioning of the collateral ligaments, and a pen or pencil can be placed in the adjacent web space at the apex of the deformity to serve as a fulcrum during angular correction. Following closed reduction, both careful assessment of rotational alignment and radiographic confirmation of desired correction are essential for a successful outcome. Cast immobilization in the intrinsic-plus position is required for 3 to 4 weeks, followed by a gradual return to activity. Although splint immobilization and earlier motion have been advocated by some, the risks of noncompliance with removable splint immobilization and the late loss of fracture reduction generally outweigh the benefits of early motion, particularly in young patients in whom posttraumatic stiffness is less common.
In rare cases, these fractures may be unstable. Such fractures tend to be high-energy injuries that disrupt the stabilizing soft tissue envelope. In these cases, closed reduction followed by pin fixation is performed, and the pins are left percutaneous to facilitate removal after 3 to 4 weeks. Smaller wires (ranging from 0.028 to 0.035 inch) and fewer wires are used than in adults.
Author’s Preferred Method of Treatment
Closed reduction and cast immobilization are recommended for patients with greater than 10 degrees of angulation or malrotation. Stable fracture reduction is achieved in the majority of cases. Cast immobilization is discontinued after 4 weeks, followed by range-of-motion exercises. Percutaneous pinning is reserved for unstable or irreducible injuries with malrotation or greater than 10 to 15 degrees of angulation. Cast immobilization is discontinued and pins are removed at 3 to 4 weeks, followed by range-of-motion exercises.
Articular Fractures of the Phalangeal Base and Epiphyseal Fractures.
Fractures of the phalangeal base with intraarticular extension represent Salter-Harris type III and IV injuries. In cases of articular incongruity, joint instability, or greater than 1 to 2 mm of displacement, closed or open reduction and smooth pin fixation are recommended to restore articular congruity, physeal integrity, and bony alignment. These injuries should be distinguished from volar plate avulsion fractures of the epiphysis. As in adults, small volar plate avulsions can be safely and effectively treated with simple Coban wrapping and “buddy taping” with early initiation of motion to avoid stiffness, provided the interphalangeal joint is stable and congruently reduced. In a prior study of 121 proximal interphalangeal joint hyperextension injuries randomized to either buddy taping or aluminum splinting, buddy taping was just as effective as splinting; in general, children had better outcomes than adults.
Comminuted, unstable proximal interphalangeal fracture-dislocations are rare in children. When they do occur, treatment principles are similar to those in adults. Open reduction and internal fixation are recommended to restore joint stability and reconstitute the articular surface. The volar base of the middle phalanx is approached via a volar zigzag incision. The A3-C1 pulleys are elevated in either a radial or an ulnar direction, and flexor tendons are retracted to allow visualization of the joint surface and displaced fracture fragments. Anatomic reduction and restoration of joint congruity are performed, followed by stabilization with size-appropriate smooth pins or screws. Bone grafting may be required to fill any impacted metaphyseal defect. Although early motion is desired, 3 weeks of cast or splint immobilization is often necessary owing to the tenuous fixation achieved and compliance issues in young patients.
Author’s Preferred Method of Treatment
Closed or open reduction and internal fixation of displaced Salter-Harris III or IV fractures are performed for cases of articular incongruity, joint instability, or diastasis of greater than 2 mm. Whereas radial and ulnar base fractures may be approached via a dorsal curvilinear incision, proximal interphalangeal fracture-dislocations with volar phalangeal base fractures require a more extensive volar approach to access fracture fragments and restore joint stability. Smooth pin fixation is used, supplemented by cast immobilization. Pins are removed in 4 weeks, followed by range-of-motion exercises.
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Surgical treatment is recommended for all displaced articular fractures, with care taken to preserve soft tissue attachments and vascularity to the displaced fracture fragment.
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Displaced phalangeal neck fractures are treated with closed reduction and percutaneous pin fixation to avoid posttraumatic interphalangeal joint stiffness.
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Percutaneous pin-assisted osteoclasis is effective in phalangeal neck fractures with persistent tenderness and radiographically visible fracture lines that present late; subcondylar fossa reconstruction may be considered in established malunions with functionally limiting loss of motion.
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Surgical reduction and fixation are recommended for displaced Salter-Harris III and IV fractures to restore articular congruity and joint stability.
Metacarpal Fractures
Treatment principles for metacarpal fractures in children are similar to those in adults. Metacarpal fractures arise from bending forces or axial loads sustained during falls, sporting injuries, or direct blows with a clenched fist. These fractures result in apex dorsal angulation secondary to the intrinsic musculature. Mild to moderate apex dorsal angulation results in little to no compromise of hand function; excessive angulation results in both aesthetic consequences and difficulties with digital extension (i.e., pseudo–claw deformity) or discomfort with forceful grasp. Closed reduction and pin fixation or open reduction of multiple metacarpal fractures results in union and return of function. Open reduction and internal fixation of intraarticular metacarpal head fractures can achieve articular restoration, but stiffness is common.
There is great variation in what is deemed “acceptable” angulation in metacarpal neck and shaft fractures, and each patient merits individualized decision making. Most authorities agree that up to 30 degrees of sagittal plane deformity is acceptable in physeal fractures, particularly in young patients with growth remaining and remodeling potential. Twenty to 45 degrees of apex dorsal angulation is acceptable in metacarpal neck fractures, with greater deformity allowable in the more ulnar digits. Shaft fractures tolerate less angular deformity, so 10 to 15 degrees of angulation is acceptable in the index and long fingers and 30 to 40 degrees in the ring and small fingers. Even mild rotational deformity (>10 degrees) results in digital overlap and functional problems. Malrotation is often undetectable on radiographic evaluation, and the importance of a thorough physical examination cannot be overstated.
In general, metacarpal fractures can be considered according to their anatomic location: epiphyseal, diaphyseal, neck, physeal, and articular fractures.
Epiphyseal Fractures.
Fractures of the metacarpal epiphysis are rare and are usually Salter-Harris III or IV fractures. These injuries result from axial loads during falls or closed fist injuries. Although nondisplaced injuries may heal satisfactorily with cast immobilization, open reduction and internal fixation are recommended for displaced fractures resulting in articular incongruity. Internal fixation using countersunk interfragmentary screws can be used in older adolescents, as in adults; smooth Kirschner wire fixation is typically used in younger children. This method of fixation provides adequate fracture stability and minimizes the risk of iatrogenic physeal injury. In rare situations, extensive comminution of primarily cartilaginous fragments occurs, and bioabsorbable pin or suture fixation is used. Osteonecrosis has been reported following these severe injuries, and soft tissue attachments to displaced fracture fragments must be preserved during open reduction. Torre has proposed that increased intracapsular pressure secondary to fracture hematoma may play a causative role, but there is little evidence to support this assertion.
Author’s Preferred Method of Treatment
Open reduction is performed via a curvilinear dorsal incision. The interval between the extensor tendon and ulnar sagittal band is developed, leaving a cuff of tissue for later sagittal band repair. After dorsal capsulotomy, the fracture hematoma is evacuated, and reduction is performed. Any soft tissue attachments are preserved to maintain vascularity to the displaced fracture fragments. Internal fixation can be performed with smooth pins, screws, or even sutures, depending on the size and integrity of the articular fragments. After adequate stabilization is achieved, the dorsal capsule, sagittal band, and skin are closed. Cast immobilization is instituted for 4 weeks, followed by range-of-motion exercises.
Metacarpal Neck Fractures.
Metacarpal neck fractures account for 56 to 70% of all metacarpal fractures in the pediatric and adolescent population. These fractures often result from closed fist injuries but may also occur after falls and sporting injuries, particularly if the affected hand is stepped on. The small finger is most commonly affected, and the characteristic deformity is apex dorsal angulation with varying degrees of rotation. These fractures usually occur through the distal metaphysis, although physeal involvement is fairly common.
Relatively large degrees of apex dorsal angulation are acceptable in ring and small finger metacarpal neck fractures, resulting in minimal impairment owing to the compensatory MP and carpometacarpal (CMC) joint motion. In young children, because the metacarpal physis is distal, remodeling of angular deformity may occur with growth. In general, angulation that is 10 to 30 degrees more than the corresponding range of CMC motion is well tolerated in skeletally immature patients.
Nondisplaced or minimally displaced fractures are effectively treated with cast immobilization for 3 to 4 weeks. Displaced injuries with malrotation or excessive angulation are treated with closed reduction and cast immobilization. Reduction maneuvers are performed under digital or wrist block using local anesthesia or conscious sedation in young patients. Reduction consists of longitudinal traction and correction of the apex dorsal angulation using three-point bending. The Jahss maneuver (i.e., flexing the MP joint to 90 degrees and applying a dorsally directed force on the metacarpal head through the flexed digit) is commonly used. The Jahss maneuver also facilitates the correction of rotational malalignment because the MP collateral ligaments are taut in flexion, and torque applied to the flexed digit is imparted to the malrotated distal fracture fragment. Adequate rotational correction is confirmed by restoration of the normal digital cascade.
Traditionally, a cast was used to immobilize the hand in the intrinsic-plus position to avoid extension contractures of the MP joint. Extension of the MP joint often results in loss of reduction, particularly in more displaced injuries. Studies have established, however, that cast immobilization for 4 weeks with the MP joints in extension (the so-called pancake cast) is safe and is not associated with long-term stiffness or MP extension contractures in young adults or children. Indeed, cast application with a three-point bending mold to maintain the desired fracture alignment is easier with the MP joints in extension.
In displaced fractures in which alignment cannot be maintained with closed reduction and cast immobilization, percutaneous pin fixation via either cross-pinning or transmetacarpal pinning techniques is performed. Intramedullary fixation, or “bouquet pinning,” has been successful in adults, but these techniques are not commonly used in children owing to the small size of the metacarpal intramedullary canals and the presence of the intervening physis. The Jahss maneuver is particularly helpful for closed reduction and pinning because it allows correction of both the apex dorsal angulation and the rotational alignment and permits pin placement within the collateral recesses without violating the collateral ligament complex. Care to minimize iatrogenic trauma to the metacarpal physis during surgical stabilization is necessary.
Metacarpal neck fractures that present late are common in the pediatric population. Because there is a large amount of compensable angular deformity via MP and CMC motion, usually no intervention is required. Excessive angulation or malrotation, particularly in the index and long finger rays, requires percutaneous pin osteoclasis or formal open reduction and internal fixation. In subacute situations (i.e., <4 weeks from injury, fracture line still visible on radiographs, tenderness still elicited at the fracture site), percutaneous pin osteoclasis can liberate the displaced fracture fragment and allow closed reduction and pin fixation. When percutaneous pin osteoclasis is not possible, open reduction or late corrective osteotomy is considered. As with other displaced physeal fractures with remodeling potential that present late, repeated forceful manipulations are avoided to prevent iatrogenic physeal arrest.
Author’s Preferred Method of Treatment
Closed reduction and cast immobilization are used for displaced injuries with excessive angulation or malrotation. In general, 10, 20, 30, and 40 degrees of angulation are acceptable in index, long, ring, and small finger metacarpals, respectively. Casting with the MP joints extended for 3 to 4 weeks is well tolerated and can be used without reservation, given the greater ability to maintain reduction and the infrequency with which long-standing stiffness occurs in young children. In unstable fractures that fail reduction and casting, closed reduction and percutaneous cross-pinning are used. Pins are removed in 3 to 4 weeks, and range-of-motion exercises are then begun.
Metacarpal Shaft Fractures.
Metacarpal shaft fractures usually result from torsional or bending mechanisms, yielding spiral or transverse fracture patterns. As in adults, isolated diaphyseal fractures, particularly of the central rays, do not displace considerably owing to the stabilizing forces of the intermetacarpal ligaments and central CMC articulations. Conversely, fractures of the border rays or multiple metacarpal fractures are inherently more unstable and display greater displacement and angulation. Nondisplaced fractures are treated with 3 to 4 weeks of cast immobilization, followed by range-of-motion exercises. Displaced injuries are treated with closed reduction and well-molded cast immobilization in the majority of cases. Serial radiographs during the period of cast immobilization are required to ensure maintenance of reduction as the soft tissue swelling subsides. Four weeks of cast immobilization is sufficient, followed by range-of-motion exercises.
Surgical indications in children are similar to those in adults and include open fractures, multiple fractures, irreducible fractures, and unstable fractures. Additional indications include fractures with extensive soft tissue injury or neurovascular injury that precludes cast immobilization. A host of surgical stabilization options is available for the treatment of metacarpal shaft fractures, including percutaneous pinning, transmetacarpal pinning, interfragmentary screw fixation, plate and screw fixation, intramedullary fixation, and external fixation. Choice of the surgical stabilization technique depends on the fracture pattern and associated soft tissue injury, as well as surgeon preference. In general, the least invasive technique that achieves the desired goals is the best choice. Surgical techniques are similar to those in adults (see Chapter 16 ), although the presence of the metacarpal physis must be considered during the decision-making process.
Author’s Preferred Method of Treatment
Isolated metacarpal shaft fractures are usually stable and are treated with cast immobilization. In cases of unstable fractures or persistent malrotation, closed reduction and percutaneous pin fixation via transmetacarpal or cross-pinning techniques are performed ( Figure 41.14 ). Pins are removed at 4 weeks, followed by range-of-motion exercises. In cases of multiple metacarpal fractures, open reduction and internal fixation with interfragmentary compression screws (long oblique fractures) or size-appropriate compression plates (transverse, short oblique, comminuted fractures) are performed via a dorsal approach.
Metacarpal Base Fractures.
Metacarpal base fractures account for approximately 13 to 20% of metacarpal fractures in children. The vast majority involve the small finger ray. Rarely, intraarticular extension is possible, with subsequent CMC subluxation or dislocation of the metacarpal shaft (the reverse Bennett fracture equivalent). Clinical evaluation includes a careful assessment of digital rotation, flexion, and extension, as well as the associated soft tissue and neurovascular status. In crush injuries or high-energy trauma, compartment syndrome can occur, and emergent decompression is required. Radiographic evaluation includes AP and lateral radiographs of the affected hand, as well as oblique views to better visualize the border metacarpals.
Nondisplaced or minimally displaced injuries are treated with 3 to 4 weeks of cast immobilization. In displaced injuries, closed reduction is performed under local anesthesia or conscious sedation, with longitudinal traction and volarly directed pressure over the typically dorsal apex of the deformity. Malrotation can be corrected simultaneously by flexing the MP joint of the affected ray and restoring rotational alignment. After cast immobilization, radiographs are necessary to confirm reduction; treatment can then continue as described earlier. In unstable reductions or CMC fracture-dislocations, surgical stabilization is required. If reduction is achieved with closed manipulation, percutaneous pin fixation using transmetacarpal pinning techniques or oblique pins into the proximal fracture fragment or carpus usually suffice. When the fracture is irreducible, formal open reduction is performed via a longitudinal incision, followed by pin fixation. Pins are removed at 4 weeks, and range-of-motion exercises are initiated.
Author’s Preferred Method of Treatment
Closed manipulation and casting are mainstays in the treatment of most metacarpal base fractures. Surgical stabilization via percutaneous pinning is used for malrotated, widely displaced, or multiple adjacent metacarpal base fractures. Transmetacarpal pinning or transarticular pinning into the adjacent carpus can be used with little morbidity or concern for long-term arthrosis.
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Open reduction and internal fixation are recommended for displaced intraarticular metacarpal head fractures.
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Closed reduction and pin fixation are recommended for unstable or rotationally malaligned metacarpal neck and shaft fractures.
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Given the remodeling potential and compensatory CMC joint motion, as much as 30 degrees of angulation may be acceptable in extraarticular metacarpal fractures.
Thumb Fractures
Phalangeal Fractures.
Salter-Harris type III fractures of the thumb proximal phalanx are common injuries in children and represent the pediatric equivalent of “gamekeeper’s thumb” in adults. The anatomy of the thumb MP collateral ligament complex explains the pattern of injury encountered. The collateral ligaments insert almost exclusively onto the proximal phalanx epiphysis, and a valgus force results in an avulsion fracture of the ulnar epiphysis rather than a pure ligamentous disruption. In cases of displaced Salter-Harris III fractures of the proximal phalanx of the thumb, surgical treatment is recommended to restore articular congruity and ligamentous MP joint stability.
Author’s Preferred Method of Treatment
Surgery is performed under general anesthesia and tourniquet control ( Figure 41.15 ). A dorsal curvilinear incision is made over the thumb MP joint. Subcutaneous dissection is performed in line with the skin incision, identifying and protecting terminal branches of the radial sensory nerve. The adductor aponeurosis is incised along its insertion on the extensor tendon. Because the ulnar collateral ligament is usually intact, the MP joint is exposed through the fracture site, and the collateral ligament is protected. If better visualization of the articular surface is necessary, the dorsal capsule is incised. The fracture is reduced under direct visualization, restoring congruity of the articular surface. Two parallel Kirschner wires are placed into the reduced epiphyseal fragment, across the fracture site, and into the opposite radial cortex. In very young children or in cases of small, predominantly cartilaginous fracture fragments, fixation with only one wire may be feasible. Intraoperative fluoroscopy is used to confirm anatomic reduction and appropriate placement of the wires. Additional sutures can be placed between the ulnar collateral ligament and the underlying periosteum. Wires are bent and cut outside of the skin. Closure is performed in layers, with careful reapproximation of the adductor aponeurosis. A thumb spica cast is applied for 4 to 6 weeks, followed by range-of-motion exercises. Formal physical and occupational therapy is usually not required.
Metacarpal Diaphyseal Fractures.
Metacarpal diaphyseal fractures of the thumb are treated according to principles similar to those used for fractures of the index through small finger rays.
Base of Thumb Metacarpal Fractures.
Base of thumb metacarpal fractures are quite common, typically resulting from falls or sporting injuries. The fracture may be metaphyseal, physeal, epiphyseal, or intraarticular; recent investigations suggest that physeal fractures are most common. Owing to the proximity to the proximal thumb metacarpal physis, these injuries demonstrate tremendous remodeling potential in young children. Impairment of hand function following displaced base of thumb metacarpal injuries is further mitigated by the nearly universal motion of the CMC joint. As a result, as much as 30 degrees of angular deformity is well tolerated, with minimal aesthetic or functional compromise ( Figure 41.16 ). In these situations, thumb spica cast immobilization for 3 to 4 weeks may suffice.
Kozin and Waters have classified base of thumb metacarpal fractures into four types. Type A fractures are those in which the fracture line passes between the physis and the junction of the proximal and middle diaphysis. These fractures are transverse or oblique and often amenable to closed reduction and cast immobilization, with excellent functional outcomes.
Type B fractures are Salter-Harris II fractures with an ulnar Thurston-Holland metaphyseal fragment and apex radial angulation. The metacarpal diaphysis is adducted by the pull of the adductor pollicis and displaced proximally by the abductor pollicis longus, thereby effectively narrowing the first web space. Excessive displacement or angulation requires closed reduction and cast immobilization to restore bony and physeal alignment. If the reduction is unstable, percutaneous pin fixation into the intact epiphysis or adjacent trapezium is performed. Rarely, open reduction is required when severe soft tissue injury and swelling preclude the ability to manipulate and maintain reduction of the fracture fragments.
Type C fractures are Salter-Harris II injuries with a radial Thurston-Holland fragment and apex ulnar angulation. Severe displacement or angulation requires closed reduction and pinning; however, comminution or soft tissue interposition may prevent bony realignment, necessitating open reduction and pin fixation.
Type D fractures are Salter-Harris III or IV fractures with intraarticular extension. This fracture pattern is the pediatric equivalent of the adult Bennett fracture, and similar treatment principles apply. Closed or open reduction with pin fixation is recommended to restore articular congruity and maintain bony reduction. As in adults, the reduction maneuver consists of longitudinal traction, pronation, and direct pressure applied to the thumb metacarpal base to adduct the thumb ray.
Author’s Preferred Method of Treatment
Base of thumb metacarpal fractures are usually treated with closed reduction and short-arm thumb spica casting. Excellent functional outcomes can be anticipated with up to 30 degrees of angulation in skeletally immature patients. In instances of fracture instability or excessive displacement not amenable to closed manipulation, closed or open reduction followed by percutaneous pin fixation is recommended ( Figure 41.17 ). When needed, open reduction is performed via a radial skin incision at the junction of the glabrous and nonglabrous skin, centered at the thumb CMC joint. Subperiosteal dissection allows retraction of the thenar muscles in a volar direction, facilitating fracture exposure. Subsequently, fracture reduction is achieved, and percutaneous pin fixation is performed. An oblique crossed-pin configuration is typically used. I avoid pinning the thumb ray to the index metacarpal across the first web space unless this is necessary to achieve adequate stability.
Wrist Fractures
Epidemiology
Although relatively infrequent, scaphoid fractures are the most common carpal bone fractures in children as well as adults, with a peak incidence in the preadolescent and adolescent age group. The lower incidence of scaphoid fractures in children may be due to the relatively thick cartilaginous cover of the developing ossification center, which protects the scaphoid. Furthermore, the anatomy and ossification pattern affect which regions of the scaphoid are susceptible to injury. The scaphoid ossifies from distal to proximal; this explains the greater frequency of distal pole fractures in young children. Previous studies demonstrated that distal pole scaphoid fractures are most common in children, followed by distal third fractures and waist fractures. The patterns of scaphoid fractures are changing, however, owing to the greater athletic and functional demands of children, resulting in an increasing frequency of scaphoid waist fractures. In their retrospective analysis of 351 scaphoid fractures in children and adolescents treated from 1995 to 2010, Gholson and colleagues noted that 71% of fractures occurred at the scaphoid waist. Distal and proximal pole fractures accounted for 23% and 6%, respectively, of that cohort. The authors concluded that with changes in activity patterns and patient characteristics, pediatric scaphoid injury patterns are now more similar to those of adults.
Unlike carpal injuries, distal radial fractures are among the most common fractures in children and adolescents, constituting approximately 20% to 35% of pediatric fractures. Similarly, distal radial physeal fractures account for approximately one-third of all physeal fractures, second in frequency only to physeal fractures of the phalanges. These fractures occur most often in patients between the ages of 10 and 14 years, in part due to the increased porosity of the distal radial metaphysis during accelerated skeletal growth. In addition, recent evidence suggests that the incidence of distal radial fractures in pediatric patients may be increasing due to greater sports participation and higher rates of childhood obesity. The vast majority of distal radial fractures occurs from a fall onto an outstretched upper limb. The wrist position (extension versus flexion) and amount of force imparted influence the ultimate fracture pattern and displacement.
Preoperative Evaluation
As in adults, fractures of the scaphoid may be subtle in clinical presentation. There may be minimal deformity or swelling, but the presence of focal, reproducible tenderness at the anatomic snuffbox or scaphoid tubercle should alert the examiner to a possible carpal fracture. Axial loading of the thumb metacarpal, loading the scaphoid during forceful pinch, and the scaphoid compression test have also been used to elicit clinical signs of a scaphoid fracture.
A suspected scaphoid fracture requires dedicated radiographic evaluation in addition to standard AP and lateral wrist radiographs. An AP radiograph of the wrist with ulnar deviation and oblique views of the wrist allow better visualization of the scaphoid. A frequently encountered clinical scenario is anatomic snuffbox tenderness and negative plain radiographs, raising the question of an occult scaphoid injury. In these situations, brief immobilization in a thumb spica cast or splint is recommended, followed by repeated clinical and radiographic evaluation in 2 to 3 weeks. If persistent tenderness is noted, advanced imaging with computed tomography (CT) or magnetic resonance imaging (MRI) may confirm or exclude the diagnosis of a scaphoid fracture ( Figure 41.18 ). Immediate MRI evaluation of all children presenting with snuffbox tenderness and negative radiographs is not recommended; the majority of these injuries are not scaphoid fractures, making such imaging and its associated time and cost unnecessary.
Similarly, patients with other fractures of the carpus may present with subtle complaints after relatively innocuous traumatic injuries. Careful observation and systematic clinical examination—with specific palpation of each bony structure of the carpus and wrist—should guide the subsequent diagnostic workup and treatment.
Unlike fractures of the carpus, the diagnosis of distal radial fractures is not subtle. Patients present with pain, swelling, and deformity of the affected wrist following trauma, such as a fall onto an outstretched upper limb. Clinical examination of the skin is performed to assess for open injuries. A neurovascular examination is similarly performed to assess for injury or impending compartment syndrome. Compartment syndrome is particularly prevalent in “floating elbow” injuries ( Figure 41.19 ). Plain wrist radiographs usually confirm the diagnosis and guide treatment. A thorough radiographic evaluation should be performed because relatively innocuous findings, such as ulnar styloid fractures or plastic deformation resulting in proximal or distal radioulnar joint disruption, can affect treatment. For example, Galeazzi fracture-dislocations are uncommon in children; instead, distal radial fractures are accompanied by distal ulnar physeal or styloid fractures. Identification of these associated injuries guides decisions regarding both nonoperative and surgical treatment strategies. In general, imaging of the entire forearm, including the elbow, is performed to evaluate for concomitant ipsilateral upper extremity fractures, which may occur in up to 13% of cases.
Distal radial fractures are generally characterized according to anatomic location (metaphysis, physis, epiphysis, intraarticular) and amount of displacement, angulation, and rotation. Physeal fractures are typically categorized according to the Salter-Harris classification. Salter-Harris type I and II patterns predominate, although Salter-Harris type III and other intraarticular fracture patterns may occur in children. In general, it is important to remember that the metaphyseal Thurston-Holland fragment in type II fractures lies opposite the disruption in the periosteum; this anatomic point assists fracture reduction maneuvers and guides the surgical approach when open operative treatment is necessary.
Pertinent Anatomy
Ossification Centers
The radiographic appearance of the carpal centers of ossification occurs in a predictable, ordered sequence. The capitate and hamate typically appear at 6 to 8 months of age. The triquetrum ossifies at 2 to 3 years of age, followed by the lunate at 4 years. The scaphoid becomes radiographically apparent at 4 to 5 years of age, followed by the trapezium and trapezoid at 5 years. The pisiform is the last carpal bone to ossify, typically at 6 to 8 years of age.
The scaphoid ossific nucleus appears between age 4 and 5 years. The bony scaphoid forms via enchondral ossification from distal to proximal until the bone is fully ossified, typically by age 14 to 16 years. Multiple ossification centers may appear, and bipartite scaphoids have been described. As discussed earlier, the gradual distal to proximal ossification process may explain the predisposition for distal pole fractures in young children and more adult patterns of scaphoid fractures (waist and proximal pole fractures) in older children and adolescents.
The secondary center of ossification of the distal radial epiphysis becomes radiographically apparent by the first year of life, whereas the distal ulnar epiphysis appears at approximate 6 years of age. The distal ulnar epiphysis often arises from two distinct centers of ossification, giving rise to a bipartite appearance that may be confused with an ulnar styloid fracture. In general, the distal ulnar physis closes at 16 years in females and 17 years in males, with the distal radial physis closing, on average, 6 months later. Knowledge of this timing and the variable patterns of ossification may assist in distinguishing acute skeletal injuries from developmental norms. Although the radiographic appearance of the distal radius and ulna changes with development, similar parameters delineate “normal alignment” in both children and adults. Evaluation of radial inclination, radial length, ulnar variance, and volar tilt is appropriate in all but the youngest patients.
Growth
Because the distal physis contributes approximately 70 to 80% of the longitudinal growth of the radius and 40% of the upper extremity, distal radial fractures have tremendous inherent remodeling potential. Prior investigations confirmed that up to 10 degrees of dorsal volar angulation per year may remodel with continued skeletal growth. As with other fractures of the developing skeleton, remodeling potential is dependent on the amount of skeletal growth remaining, distance from the bony injury to the adjacent physis, magnitude of the deformity, and plane of the deformity. Fractures close to the distal radial physis with mild to moderate angulation in the sagittal plane in younger patients have the greatest remodeling potential. Therefore, in patients younger than 10 to 12 years, 20 to 30 degrees of angulation in the sagittal plane and 50 to 100% translation of the distal radial fracture fragment may remodel with continued skeletal growth. Radioulnar angulation in the coronal plane is less well tolerated and has less remodeling capacity. Therefore, angulation of more than 10 degrees in the AP plane may not remodel with continued skeletal growth.
Soft Tissue Structures
A number of soft tissue structures impart stability to the wrist and must be considered in the treatment of skeletal injuries. Carpal stability is imparted by both extrinsic and intrinsic ligaments, with anatomic and pathologic considerations similar to those in adults. A discussion of carpal instability due to ligamentous injury is beyond the scope of this chapter; see Chapter 13 for further information. Owing to the relative mechanical strength of these ligaments in relationship to the adjacent bony structures, intrinsic carpal ligamentous injuries are far less common in children than in adults. Furthermore, due to the gradual ossification process of the carpus in skeletally immature patients, the “normal” radiographic parameters used to identify intrinsic ligament disruptions (e.g., scapholunate ligament tears) may not be applicable in younger children.
The triangular fibrocartilage complex (TFCC) refers to a confluence of structures on the ulnar side of the wrist, including the triangular fibrocartilage, dorsal and volar radioulnar ligaments, meniscal homolog, ulnolunate and ulnotriquetral ligaments, and subsheath of the extensor carpi ulnaris tendon. Functionally, the TFCC provides a smooth articular surface in support of the ulnar carpus and stabilizes the distal radioulnar joint (DRUJ). In ulnar-neutral wrists, approximately 20% of the axial load across the wrist is borne by the ulnar carpus through the TFCC. Small changes in ulnar variance, as might be seen with traumatic or posttraumatic deformity, may result in considerable alterations in loads transmitted across the TFCC and ulnar wrist.
Types of Operations for Wrist Fractures
Scaphoid Fractures
As in adults, treatment of scaphoid fractures in skeletally immature patients is dependent on the fracture location, fracture pattern, and degree of displacement. Distal pole fractures have excellent healing potential owing to the vascularity of the distal pole of the scaphoid and their extraarticular locations. Thumb spica cast immobilization for 4 to 6 weeks is adequate, particularly in cases of incomplete or avulsion injuries ( Figure 41.20 ).
Nondisplaced waist fractures can be treated with cast immobilization, with union rates greater than 90% (see Figure 41.17 ). However, cast immobilization for 2 to 3 months may be required in these situations, owing to the limited and retrograde vascular supply to the scaphoid body, which is the same as in adults.
The optimal type of cast immobilization continues to be debated. Incorporation of the thumb into a spica cast has been advocated by some to eliminate forces across the scaphoid, which may inhibit healing or cause displacement. In addition, immobilization of the elbow eliminates forearm rotation, which has been demonstrated to induce scaphoid fracture motion. Gellman and associates performed a prospective randomized study comparing long-arm versus short-arm thumb spica casting for the treatment of acute nondisplaced scaphoid waist fractures. Patients treated with long-arm casts for the first 6 weeks had a faster time to healing (9.5 versus 12.7 weeks) and lower nonunion and delayed union rates than those treated with short-arm casts alone. Other recent investigations have demonstrated no significant differences in times to union between short-arm and long-arm casts. Several biomechanical and clinical studies evaluated the effect of wrist position on scaphoid healing during casting. Arguments have been made for casting with wrist extension, wrist flexion, and radial and ulnar deviation.
As in adults, there is growing enthusiasm for percutaneous screw fixation for nondisplaced injuries, given contemporary expectations of a faster return to sports and activities in younger patients. It is unclear whether these adult principles apply to the pediatric patient with scaphoid fractures, and there is some evidence that percutaneous screw fixation of nondisplaced injuries in children and adolescents does not decrease the time to union. Discussion of percutaneous screw fixation is beyond the scope of this chapter; however, considerations and surgical techniques are similar to those in adults (see Chapter 18 ).
In cases of displaced waist fractures or fractures of the proximal pole, surgical treatment with open reduction and internal stabilization is recommended, as in adults. Because these injuries tend to occur in older children and adolescents, the treatment principles and surgical techniques are similar to those in adults. Internal stabilization with smooth Kirschner wires, headed compression screws, or variable-pitch headless compression screws has been used safely and effectively in children.
Scaphoid fracture nonunion does occur in skeletally immature patients, owing either to late presentation or to inadequate immobilization of acute injuries ( Figure 41.21 ). Indeed, in their retrospective analysis of 351 scaphoid fractures in children and adolescents, Gholson and coworkers noted that 29% of patients presented more than 6 weeks from injury. Typically, patients are older adolescents with waist or proximal pole fractures. Treatment options for established pediatric scaphoid nonunions are quite varied. Historically, cast immobilization has been advocated in injuries that present late. Bone grafting via the Matti-Russe technique, Kirschner wire fixation, and compression screw fixation have also been reported, with successful outcomes in the majority of cases, consistent with the published adult literature ( Case Study 41.1 ). The use of autologous bone graft is common to provide structural support and facilitate healing.
A 10-year-old right-handed patient had hurt his left wrist 6 months previously. He complains of persistent pain and decreased range of motion ( eFigure 41.1, A and B ). The diagnosis was scaphoid nonunion. The treatment options included a long-arm cast, electrical stimulation, open reduction and vascularized bone grafting, and open reduction and nonvascularized bone grafting. The option of open reduction and nonvascularized bone grafting ( eFigure 41.2, A to F ) was performed. Postoperative and 3-month follow-up x-rays are shown ( eFigures 41.3, A and B, and 41.4, A and B ).
Osteonecrosis of the proximal pole of the scaphoid may occur in children, typically in waist or proximal pole fractures in patients nearing skeletal maturity. Reconstructive procedures using pedicled vascularized bone graft from the distal radius have been recommended in these rare but difficult situations.
Little is known of the natural history of scaphoid fracture malunions (e.g., humpback deformity) in skeletally immature patients. Although reports of spontaneous correction of secondary carpal instability and remodeling of scaphoid malunions have been published, no definitive statement can be made owing to the infrequency of these situations and the paucity of data available.
Author’s Preferred Method of Treatment
Fractures of the distal pole of the scaphoid are treated with short-arm thumb spica cast immobilization for 4 to 6 weeks, followed by gradual resumption of activities with the return of wrist motion and strength.
Nondisplaced fractures of the scaphoid waist, confirmed by CT scans with reconstructed images in the plane of the scaphoid, are treated with short-arm thumb spica cast immobilization until there is radiographic evidence of healing (see Figure 41.18 ). Routine CT scans are not performed if there is clinical and radiographic evidence of fracture healing, including bridging trabeculae on multiple radiographic views. In situations in which prolonged cast immobilization is not a viable treatment option (e.g., bilateral upper extremity fractures, high-level athletes), percutaneous screw fixation via a dorsal approach is considered.
Displaced fractures of the scaphoid waist and fractures of the proximal pole are treated with open reduction and internal fixation via standard volar and dorsal approaches, respectively. Internal fixation is performed using a headless, cannulated, variable-pitch compression screw.
Scaphoid nonunions of the waist are treated with open reduction, bone grafting, and internal fixation. In cases of dorsal humpback deformity and dorsal intercalated segment instability, interpositional tricortical iliac crest bone graft is used to restore normal scaphoid architecture and reconstitute carpal alignment. Intraoperative pinning of the radiolunate joint to reduce the lunate out of its dorsiflexed position is often performed, although the pin is removed on completion of the case (see Figure 41.21 and ). Provided appropriate alignment and stability are achieved, patients are placed in a short-arm thumb spica cast, followed by wrist immobilization after radiographic evidence of bony healing.
Capitate Fractures
Capitate fractures are rare and typically result from high-energy mechanisms of injury, such as motor vehicle collisions or falls from great heights during sports. Occasionally, they may be seen in association with a greater-arc perilunate fracture-dislocation injury. Thus, the x-ray should be inspected for concomitant lesser- or greater-arc injuries. Radiographs usually confirm the diagnosis, but advanced imaging studies (e.g., CT, MRI) are helpful to identify fracture displacement and associated wrist pathologic conditions ( Figure 41.22 ).
Treatment is predicated on fracture pattern and displacement. Nondisplaced capitate fractures are effectively managed with cast immobilization. Displaced injuries require open reduction and internal fixation using smooth pins or compression screws. Associated pathologic conditions (e.g., lesser- or greater-arc perilunate fracture-dislocations) should be addressed simultaneously.
Triquetrum Fractures
Although triquetral body fractures are rare and may be seen in the setting of greater-arc perilunate fracture-dislocations, dorsal avulsion fractures do occur, particularly in older adolescents ( Figure 41.23 ). The former require open reduction and internal fixation, but the latter do well with splint or cast immobilization for 3 to 4 weeks until symptoms subside.
Hamate Fractures
Hamate fractures are relatively uncommon in the pediatric population. Fractures of the hamate hook predominate, secondary to a fall. Patients present with point tenderness along the palm and hook of the hamate, along with mild swelling or localized ecchymosis. In acute or chronic cases, patients may complain of paresthesias or weakness in an ulnar nerve distribution or discomfort with small and ring finger flexion, owing to the proximity of the neurovascular and tendinous structures to the hamate hook. Standard radiographs may not delineate the fracture, and the carpal tunnel view may be helpful in suspected cases. CT is becoming the standard of care for the diagnosis of these fractures ( Figure 41.24 ). Although open reduction and internal screw fixation have been advocated by some, short-arm cast immobilization for 4 to 6 weeks often alleviates the symptoms and allows a full return to activities, despite persistence of a radiographic fibrous nonunion. In persistent cases of symptomatic nonunion, fracture fragment excision is performed for relief of symptoms, although athletes should be advised of the possibility of scar irritation or sensitivity. The surgical approach for either fixation or excision is a standard zigzag approach to the Guyon canal or through a carpal tunnel release incision.
