12.11 Functional bracing

During the past five decades, considerable progress has been made in the surgical treatment of a number of fractures, so much that many non-surgical modalities have been rendered obsolete and replaced by more effective surgical approaches. The most obvious examples are the fractures of the hip, and the femoral shaft. Rarely, are these fractures treated non-surgically.

Despite such progress, surgical treatments have their limitations and the potential for anatomical reduction is not necessarily synonymous with excellent clinical results. In some instances, complications such as infection are difficult to overcome. Plating and external fixators that rigidly immobilize fracture fragments can delay healing, because the osteogenic stimulus of interfragmentary motion is absent. In addition, the cost of surgical treatment is in many cases a great deal higher than that of conservative treatment.

It must be concluded that a rational balance between the two therapeutic approaches is essential for the best way to deal with specific clinical conditions.

Functional casting or bracing of certain long-bone fractures is a relatively new approach to care. It is a philosophy of management predicated on the premise that immobilization of fractured long bones and their adjacent joints is unphysiological and detrimental to healing, and that physiologically induced motion at the fracture site enhances osteogenesis. This premise does not fail to recognize that immobilization of fractures is often desirable, and in many instances the best means to achieve healing, while providing final acceptable cosmesis and limb function.

Our initial techniques for functional casting and bracing of fractures have undergone major change over the years, and have proven to be inappropriate in the care of many fractures such as metaphyseal and diaphyseal femoral fractures where internal fixation is more appropriate. Bracing of fractures of both bones of the forearm was practically abandoned because the implementation of the technique was difficult and the maintenance of reduction was often impossible. However, some profitable lessons were learned in the process, such as the realization that closed oblique or comminuted fractures of both bones if simply appropriately aligned, maintain the initial, usually acceptable, shortening without synostosis, while permitting unencumbered motion of the elbow and wrist. In addition it provided information regarding the ultimate limitation of motion that accompanies various degrees of angular deformity.

Bracing of diaphyseal tibial, humeral, and isolated ulnar fractures has been proven highly successful in most instances.

Functional casting and bracing offers good results in the vast majority of closed axially unstable diaphyseal tibial fractures that experience, at the time of the injury, an acceptable degree of shortening and an easily correctable angular deformity. Transverse fractures can also be managed in this way when a stable reduction can be manually obtained. These criteria were established upon recognition that the vast majority of closed fractures initially suffer less than 0.5cm of shortening. This degree of final shortening is inconsequential from the physiological, functional, and aesthetic point of view. Through clinical and laboratory investigations we have proven that the initial shortening does not increase with the introduction of graduated weight-bearing ambulation. Beyond those criteria, tibial fractures with intact fibula that demonstrate initial varus angulation should not be braced because of the likelihood of increased deformity.

Diaphyseal tibial fractures that are to be treated by non-surgical means are best stabilized initially with a well-padded above-the knee cast that extends from below the groin to the base of the toes. The knee joint is flexed to approximately 7–10 degrees. Further knee flexion to prevent weight bearing is not necessary as additional shortening does not increase in the case of closed tibias. If there is significant swelling at the time of the first evaluation of the patient, or additional swelling is anticipated because of the severity of the injury, a circular cast is not advisable. A posterior splint may be used or the posterior half of the bivalved above-the-knee cast. The ankle joint is best held at 90 degrees of flexion. Forceful dorsiflexion should be avoided in order to prevent the development of recurvatum deformity at the fracture site. The limb should be elevated at rest and observed for compartment syndrome. The functional cast may be applied as soon as the acute symptoms subside, which in most instances occurs within the first 2 post-injury weeks. To apply it while the leg is still painful is an unwarranted and unnecessary experience. On the other hand, postponing its application until ‘early callus’ is seen on radiographs is also a misguided and erroneous practice. By the time callus is seen on the tibia, the faster healing fibula is likely to be solidly healed, creating a situation similar to that of an acute tibial fracture with an intact fibula, leading to the development of angular varus deformity.

If the cast is to be used in preference to the brace, it is best to postpone its application until the swelling has decreased to a greater degree, simply because the circular cast lacks the adjustable features to accommodate the reduction of swelling and limb atrophy that the brace possesses.

The functional cast, mistakenly called a PTB (patellar tendon bearing) cast because it resembles the moulding of the PTB prosthesis worn by the amputee, is applied in three stages.

The freedom of the knee joint is made possible by trimming the proximal cast (Figure 12.11.1D). Anteriorly, to just above the proximal pole of the patella; laterally, as far posteriorly as possible without impinging on the hamstring tendons; posteriorly, at a point opposite the tibial tubercle. The completed trimming should make possible full flexion and extension of the knee (Figure 12.11.1E, F).

Once the casting material has dried, ambulation with the aid of a walker or crutches may begin. Symptoms should dictate the degree of weight bearing. It is increased gradually.

The surgeon might prefer to askew the functional cast, and go directly to the functional brace. The appropriate timing for its application is the same used for the application of the functional cast. That is, evidence of subsidence of acute pain and disappearance of significant swelling distally. If applied before these criteria are met, undesirable discomfort and persistence of distal oedema will result.

The brace can be custom-made or prefabricated. It extends from the level of the proximal pole of the patella and extends to just above the ankle. It must be held firmly in place against the soft tissue with Velcro straps (Figure 12.11.3A,B).

The brace is applied with the patient sitting on a high table, holding the hip and knee at 90 degrees of flexion. The functional brace is fitted over a layer of stockinette. The completed brace should allow full flexion and extension of the knee and ankle. If this is not possible because the brace is too long, the proximal or distal ends of the shells can be trimmed down with scissors (Figure 12.11.3C).

Instructions to the patient should consist of avoidance, during the first few days, of prolonged sitting with the knee flexed. Elevation of the leg and frequent active flexion and extension of the ankle expedite the subsidence of swelling and the restoration of motion. Ambulation can begin from the outset with the use of crutches. The degree of weight bearing is determined by the degrees of discomfort. There is nothing to be gained from forcing patients to bear weight if such an action is painful. The straps must be adjusted frequently several times during the first few days, and twice a day afterwards, in order to accommodate the new geometry of the limb created by the reduction of swelling. It is this firm compression that controls angular deformities.

The brace should not be removed for approximately 1 week, at which time the surgeon removes the brace and inspects the extremity. New x-rays are taken at this time. If clinically and radiographically there appear to be no problem, the patient is taught how to apply and remove the brace without assistance (Figure 12.11.4).

Non-surgical functional treatment of diaphyseal humeral fractures has been highly successful, with a very low incidence of non-union and acceptable functional and cosmetic results.

Patients with diaphyseal humeral fractures who are selected for non-surgical functional management are usually those with closed fractures that do not suggest extreme degrees of soft tissue damage, which is usually depicted by major axial separation between the major fragments. In order to provide comfort during the early acute stage of the process, an above the elbow cast or a coaptation splint is applied (Figure 12.11.5). The elbow should be held at approximately 90 degrees of flexion. A sling is essential, and must be attached while the shoulder is in a relaxed position; otherwise an angular deformity is likely to develop when the shrugged shoulder relaxes (Figure 12.11.6).

Circumduction (pendulum) exercises, in the sling, should begin within the first couple of days following the initial injury. Under no circumstances should the patient be encouraged to actively abduct or elevate the shoulder. These active exercises readily lead to angular deformity and increase the likelihood of non-union.

In most patients with diaphyseal humeral fractures sustained from relatively low energy injuries, the functional brace may be applied within the first week of injury. However, if the extremity is still very painful and significant swelling is present at that time, it is best to postpone the application of the brace by a few more days.

The brace is applied while the patient is sitting in a high chair with the arm in a relaxed position. Since it is likely that the elbow will be limited in flexion because of the preceding days of immobilization, the arm should be supported by the patient’s normal hand (Figure 12.11.7). A layer of stockinette is rolled over the upper arm, extending from the acromioclavicular level to below the elbow.

The prefabricated brace, which is made of two separate shelves, is slipped over the arm until it reaches a point below the axilla. Once this has been accomplished, the Velcro straps are firmly adjusted.

Braces that extend over the acromium do more harm than good. They have been allegedly designed to prevent their distal slippage. Although it is possible that in some stances this is accomplished, the necessary soft tissue compression is lost and pain or discomfort ensues.

Following the application of the brace, circumduction exercises, in sling, should be reinitiated. A few days later, in accordance with the degree of symptoms, the patient is instructed to start passive flexion and extension of the elbow. These exercises are then combined with active contractions of the flexors and extensors of the elbow. These exercises might favourably correct any rotary deformity that may have developed at the time of the injury. Once the elbow reaches full extension, and the acute symptoms have disappeared, circumduction exercises in extension may be started. These exercises must be conducted gingerly and without pain. During rest, the arm is best held in the sling until clinical evidence of early intrinsic healing has been demonstrated (Figure 12.11.8). Active flexion and abduction should be postponed until the fracture shows early callus formation in order to avoid angular deformities.

Plating of isolated ulnar fractures is a popular method of treatment. Postoperative infection is low and non-union and implant failure do not occur with great frequency. However, refracture following plate removal is not uncommon and the costs of surgical treatment remain high.

The popularity of surgical plating came as a result of observing that non-union was not infrequently encountered when the limb was immobilized in a cast that extended from the head of the metacarpals to above the elbow. Such a cast had been used as it was believed that the joint above and below a fracture required immobilization. Today, the theory of rigid immobilization has been proven flawed, and replaced with evidence-supported data that freedom of motion of joints and physiologically induced motion at the fracture site are conducive to diaphyseal fracture healing. The high rate of success with functional bracing of isolated ulnar fractures makes it difficult to justify the routine plating of these fractures. There are, however, instances when open surgery is the treatment of choice, such as in the case of open fractures with severe soft tissue damage or major displacement of the fragments.

Since isolated ulnar fractures are usually the result of direct blows over the forearm, the most common displacement of the fragments is in a radial direction. Since the injury produces minimal to moderate damage to the interosseous membrane, its stabilizing role is rarely compromised. Shortening is not possible, since the intact radius prevents such a development. When the forearm is placed in a relaxed attitude of supination, the angular deformity usually improves. In any event, the common residual angulation does not result in a noticeable loss of prono-supination. It is our view that the surgical trauma produced at the time of plate fixation is more likely to create a greater degree of limitation of motion. A synostosis between the two bones is a complication we have not observed with the use of functional braces.

Initial angular deformity in a volar direction is usually of a mild degree and the clinical consequences are rarely of any significance. This type of angulation is easily correct by gently, steady pressure at the apex of the fracture for a few minutes. Major angular deformity may be seen in severe open fractures associated with significant amount of soft tissue damage. These fractures require stabilization with internal or external fixation. Low-grade open fractures can be treated with functional bracing following appropriate debridement of the injured soft tissues.

These observations suggest that the majority of isolated ulnar fractures can be successfully treated with functional braces that permit early use of the extremity without the need for complete prevention of prono-supination of the forearm and flexion and extension of the elbow and wrist.

We recognize that the functional brace does not immobilize the fractured fragments. This is a desirable feature, since immobilization retards healing. This is true for all other types of braces used in the care of tibial or humeral fractures. In the case of the ulna, the brace simply provides comfort and holds the forearm in the desirable relaxed attitude of supination, which assists in maintaining the two bones as far apart as possible.

Successful results have been achieved treating isolated ulnar fractures with the simply use of an elastic bandage. However, the brace provides a degree of comfort the bandage does not accomplish.

Patients are encouraged to use the extremity to the maximum degree allowed by pain. In most instances the pain present at the time of application of the brace is only moderate. It is our opinion that the early introduction of function results in a more rapid disappearance of acute symptoms and faster healing. The brace should be short enough to make possible free motion of the wrist and elbow, regardless of the location of the fracture (Figure 12.11.9).

Flexion and extension of the elbow are rapidly regained. Pronation and supination required a longer period of time because such motions are more painful. In a few instances we have treated with functional braces patients who had sustained bilateral isolated ulnar fractures. Their recovery was rapid and uneventful.

The brace should be adjusted on a frequent basis during the first few days in order to maintain the desirable compression of the soft tissues and to prevent the distal displacement of the sleeve over the wrist. The brace may be removed for hygienic purposes as often as necessary and the collar-and-cuff permanently discontinued as soon as the symptoms subside.

Obviously, rigid immobilization of fragments is not necessary. All the brace accomplishes is probably nothing more than provision of comfort and protection to the arm from inadvertent forceful contact with hard objects (Figure 12.11.10).