Chapter 19 Functional bracing of selected upper limb fractures
Functional fracture bracing is a philosophy of fracture care predicated on the premise that rigid immobilization of fractured limbs is unphysiologic and detrimental to fracture healing and that physiologically induced motion at the fracture site enhances osteogenesis.6,21,25
After extensive human and animal experimentation,10,16,19,20–22,25 we concluded that, contrary to popular belief, closed fractures in the two segments of the body with two long bones experience the maximum and final shortening at the time of injury.21,22,25,26 For example, a closed fracture of the tibia and fibula or of both bones of the forearm that demonstrates an initial shortening of 0.5 cm does not shorten any further after introduction of graduated weight-bearing ambulation or active use of the injured extremity. This fact contradicts the long-held perception that weight bearing on a fractured extremity causes additional and progressive shortening.
We initially emphasized the role of functional fracture bracing in the care of many different fractures and under a wide variety of circumstances. However, experience gained over the years prompted us to recommend its use for fewer types of fractures, not only because of failure to attain consistent satisfactory results with some of them but because of the great progress being made with other methods of treatment, particularly closed intramedullary nailing of long bone fractures.
Functional bracing can be accomplished with the wide variety of materials and devices available today. This chapter does not attempt to cover all the possible ways in which the philosophy of functional bracing can be achieved. We focus on the most recent developments and the most recent orthotic designs. The most easily applied devices are fully prefabricated orthoses.
Functional bracing is predicated on the premise that physiologically induced motion at the fracture site is conducive to osteogenesis; therefore, immobilization of joints adjacent to the fracture and rigid fixation of fragments are detrimental to fracture healing.6,26 It also is based on the realization that anatomical restoration of alignment is not necessary in the management of most diaphyseal fractures. Minor shortening, angulation, and rotation are not functional complications but simply inconsequential deviations from normal.
The humeral diaphysis tolerates well the minor posttraumatic deviations. As a matter of fact, the tolerance is greater than it is with most other long bones. Fifteen degrees of varus angulation is cosmetically difficult to detect in most instances. In heavy or flabby people, 25 to 30 degrees may be aesthetically acceptable, without compromise of function.
Not all diaphyseal humeral fractures are suitable for functional bracing. Other methods of treatment, such as internal fixation in the form of plating or intramedullary nailing or external fixation, are more appropriate under certain circumstances.
In order for a patient with a humeral fracture to truly benefit from bracing, he or she must be able to assume the erect position, cooperate with the physician, and be capable of adjusting the brace or have someone available who can provide that service on a regular basis. These are requirements because dependency of the extremity is necessary for restoration of adequate alignment of the fragments (Fig. 19-1) and because, during the early days, the brace must be adjusted several times daily as swelling decreases and muscle atrophy takes place.
The majority of closed humeral diaphyseal fractures can be treated with functional bracing. Patients who cannot follow instructions or for other reasons cannot perform early passive exercise routines, which are crucial for a good outcome, should not be braced. These individuals include patients with multiple injures who are confined to bed for extended periods of time and those with insensitive arms. Patients with major open wounds cannot be managed early with braces and require other means of care until soft-tissue healing is sufficiently improved, after which the brace can be applied. The presence of an associated radial palsy does not preclude functional bracing.
The level of the diaphyseal fracture is not important. The brace does not need to cover the fracture site itself because its effectiveness is dependent on compression of the surrounding soft tissues. However, fractures of the surgical or anatomical neck of the humerus and those with distal intraarticular involvement require other therapeutic approaches.
Patients with closed, isolated low-energy produced fractures of the humeral diaphysis rarely require hospitalization. One of the most typical closed, low-energy mechanisms of injury is a rotational force. In most instances these fractures do very well with functional bracing. The high velocity and high energy of the injury may cause comminution and/or segmental fracture. Most of these fractures also do well with functional bracing. However, if the trauma is severe and significant swelling or pain seems to be disproportional, in-hospital observation is desirable because of the possibility of developing a muscle compartment syndrome. This condition, if diagnosed, requires close attention and early surgery. In the absence of signs and symptoms suggestive of a possible compartment syndrome, the patient with a closed fracture of the humerus should have the injured extremity stabilized in either an above-the-elbow cast or a coaptation splint that leaves the forearm and hand exposed. In either case, a collar and cuff must be applied for additional comfort and to minimize distal edema.
It is of the utmost importance for the patient to relax the shoulder at this time. Ordinarily, the patient is apprehensive about the possibility of experiencing pain during application of the brace and unconsciously shrugs the shoulder. If the brace is fit while the shoulder is elevated, it is very likely that a varus deformity at the fracture site will occur upon relaxation of the musculature.
Once the cast or coaptation splint is applied, the patient should begin exercises of the hand and pendulum exercises of the shoulder. Because the first attempts to actively carry out pendulum exercises of the shoulder likely will be associated with pain, it is best for the patient to hold the injured extremity with the nonaffected hand. In this manner, the patient swings the arm in a circular manner as well as in alternate directions of adduction and abduction and forward and backward motions. These exercises are best conducted while leaning forward. The exercises soon can be conducted in an active manner. The sling should be used while the patient is in the recumbent position and during the early stages of healing. It can be gradually discontinued. Most patients may discard the sling once the elbow reaches full extension.
Open fractures associated with major soft-tissue damage and significant displacement between the fragments require surgical debridement of the wound and some type of stabilization. In these instances, external fixation or plating often is the treatment of choice. Many prefer plating when the fracture is associated with a proven laceration of a major nerve or artery injury. Intramedullary nailing also may be an appropriate treatment under those circumstances, although the complication rate from nailing is high. However, if the soft-tissue damage is not major and there is no vertical distraction between the main fragments, functional bracing can be used effectively.
The presence of separation between the fragments in an axial direction suggests major damage to the surrounding musculature and might lead to nonunion. This is most likely to occur with transverse fractures. At times, the axial distraction between the major fragments disappears spontaneously within a short period of time, suggesting that the soft-tissue damage was not significant. In those instances, functional bracing usually renders good clinical results. Distraction usually is greater when nerve damage is present. Fractures of the humerus associated with brachial plexus injuries have a guarded prognosis. Nonunion is common. Surgical stabilization may be the treatment of choice.
Subluxation of the shoulder is common following the initial immobilization. It is best managed by active flexion and extension of the elbow. Because both flexor and extensor muscles have attachments on the scapula and distal humerus, their contraction forces the humeral head into the glenoid.
Most closed fractures with associated radial palsy can be treated with functional bracing in anticipation of spontaneous recovery. This is true especially if nerve palsy develops immediately after the injury. A dorsal cock-up wrist splint usually is not necessary if no contraindications exist for early gradual extension of the elbow. Once the elbow is extended, the partially paralyzed wrist spontaneously extends, preventing the development of a flexion–contracture of the joint.
If the palsy appears later, the prognosis is more guarded and suggests encroachment of the nerve by the forming callus. Magnetic resonance imaging (MRI) and electrical studies should be conducted to rule out the possibility of serious pathology. If pathology is identified, surgical exploration is necessary. Following repair of the nerve, the fractured humerus should be stabilized with either an external fixator or a plate.
Manipulation of a diaphyseal fracture of the humerus is strongly criticized because of the danger of producing nerve damage. Most angular deformities correct spontaneously as the brace compresses the soft tissues and the weight of the arm assists in improving alignment (Fig. 19-1). Most angular deformities are physiologically and cosmetically tolerated. In rare cases when an unacceptable deformity persists, a surgical intervention is required.
In most instances, it is possible to exchange the cast for a functional brace between the end of the first and second postinjury weeks. This period of time usually is required for the subsidence of acute symptoms and the development of the patient’s ability to perform the necessary exercises.
Whenever possible, the cast should be removed with the patient sitting on a high table. The brace is applied in the same position. After the arm is cleansed, a layer of stockinette is carefully rolled over the extremity, extending from just below the elbow to the level of the acromion process (Fig. 19-1). The appropriate size of brace is selected by measuring the length of the upper arm from approximately 1 inch below the axilla to 1 inch above the lateral condyle of the humerus.
The brace should not press superiorly against the axilla because it will produce discomfort and sufficient pressure to lacerate the skin and force the patient to hold the arm in an abducted position. A varus angular deformity then occurs.
The collar and cuff are applied holding the elbow at 90 degrees. Exercises similar to those carried out during the cast immobilization period should continue. At first, the exercises should be passively assisted with the opposite hand. As soon as the patient realizes that the passive motion of the shoulder is not associated with pain, he or she should begin to combine the passive motion with active contraction of the biceps and triceps. The contraction of the flexors and extensors of the elbow assists in the correction of rotary deformities. This is possible because the two muscle groups have attachments to the proximal and distal fragments of the fracture. The malrotation of the bones at the time of the injury is accompanied by a parallel coiling of the muscles. Once they contract, they correct the rotary bony deformity.21
The brace must be adjustable, otherwise maintenance of firm compression on the soft tissues surrounding the fractured humerus is not possible. The snug fit of the brace provides comfort to the patient and permits the continued use of the injured extremity in a gradually progressive manner.
The brace should extend from approximately 1 inch below the axilla to approximately 1 inch above the humeral epicondyles. It does not necessarily have to extend above and below the fracture site. The important thing is the compression of the soft tissues around the fracture site. The sleeve should not extend over the acromion or the epicondyles of the humerus. The sleeve should not be suspended with a harness over the shoulder.
The proximal extension over the acromion does not add to the effectiveness of the sleeve. However, it can do harm by wrongly suggesting that in this manner the sleeve does not displace distally and provides greater stabilization to the fractured humerus. The extension of the brace over the epicondyles is another exercise in futility because in order for the condyles to prevent its distal slippage, a significant amount of pressure over the skin would be necessary, which might lead to pain and pressure sores.
The patient should be instructed to continue pendulum exercises with the arm held in the sling, to be followed by similar exercises with the elbow in extension at a later date. Only after this time can the sling be temporarily discontinued. The sling should be worn only at night and discontinued once clinical and radiological stability have been achieved.
The exercises of the extremity should not be limited to the shoulder and elbow; they should include the hand and wrist. In this manner swelling is decreased. The arm must hang loosely at the side of the body so that gravity forces can assist in correcting the angular deformities. Leaning on the elbow should be strongly discouraged because it produces angular deformities. This may occur during the initial period of cast immobilization but more likely after application of the brace.
As atrophy takes place and swelling decreases, the brace has a ready tendency to slip distally. This slippage not only can produce irritation of the antecubital space but can result in loss of compression of the soft tissues. This compression is essential for the maintenance of fracture alignment and stabilization of the fragments. Therefore, it is important to use adjustable braces. As swelling subsides and muscle atrophy experiences recovery, the need for frequent adjustment of the brace decreases. The patient should be instructed to remove the brace for hygiene after bathing. The brace should be removed, the stockinette replaced with clean dry stockinette, and the brace reapplied.
Active abduction and elevation of the arm should be avoided until early radiographic evidence of healing is seen. Therefore, only passive exercises and active exercises that do not call for strong contraction of the abductors and elevators of the shoulder should be conducted. Once intrinsic stability at the fracture occurs, active elevation and abduction should be conducted. Physical and/or occupational therapy, if prescribed, should be limited to the exercises described previously.