SUPRACONDYLAR FRACTURES OF THE HUMERUS

Abstract

Non operative treatment of supracondylar fractures of the humerus has almost always resulted in failure. Closed reduction followed by prolonged immobilization until union, may be associated with an acceptable X-ray but with unacceptable function because of marked stiffness. Traction and early motion preserves movement but the incongruity of the joint leads to instability, early post-traumatic arthritis and pain. Traction also requires prolonged hospital admission which is not possible in modern health care settings. Attempts at early motion without reduction, the so called “bag of bones treatment” leads to gross malunions, non-unions and poor function.

In order to function normally an elbow requires stability, a congruent articulation, freedom from pain, and a functional range of motion. After fracture one can achieve a normal elbow only after anatomic reduction fracture which is combined with absolutely stable fixation and early motion.

These fractures are classified according to the Comprehensive Classification into Types: A, B, and C, with their respective groups and subgroups, all arranged in an ascending order of severity. Once a surgeon classifies a fracture he gains insight into the associated problems in treating it. Classification thus helps in proper decision making.

In young patients these fractures are usually the result of a high energy trauma. Although multifragmentary and at times open, these are fractures of normal bone and are therefore often amenable to secure fixation.

In the elderly the commonest mechanism is a slip and fall on to the point of the elbow. The olecranon is driven into the trochlea and splits the osteoporotic condyle of the humerus into a multitude of fragments. The resultant fractures are multifragmentary, displaced and often defy attempts at reduction and fixation.

When one is deciding on treatment the factors which must be considered are patient factors, the fracture factors, and the treatment factors. The most important factors are: the patients age and the degree of osteoporosis, the comminution and displacement of the fractures, the association of neurovascular injuries, and whether the fracture is open or closed.

An open reduction and internal fixation is best performed with the patient on the side with the injured elbow uppermost, or with the patient prone. The best surgical approach is posterior. Once the skin is incised one must isolate and protect the ulnar nerve. The facture is exposed by carrying out an osteotomy of the olecranon. In elderly patients in whom a prostheses might become the salvage, one should consider using a triceps splitting approach or a triceps peal as for an elbow arthroplasty.

Commence fixation with an anatomic reduction of the trochlear fragment to the capitellar fragment. If bone is missing than instead of lag screws one uses fully threaded screws to prevent the narrowing of the distal articulation. Once securely fixed, the articular complex is fixed to the metaphysis and shaft. The fixation is carried out with two plates which should be positioned at 90 degrees to each other to achieve the strongest biomechanical construct. The plates commonly used are the 3.5mm LCDCP plates or the 3.5mm reconstruction plates. The choice of one or the other plate depends on the fracture pattern and on the necessary contouring of the plates. The usual choice are two reconstruction plates one medially and one posteriorly contoured to fit the posterior aspect of the capitellum which is devoid of articular cartilage. Such fixation is particularly useful in distal fractures. If there is metaphyseal bone loss one should use at least one LCDCP since these are stronger than the reconstruction plates.

Post-operatively the elbow is immobilized in 120–150 degrees of extension and is elevated for 24–48 hours. Early active motion should commence no later than day three in order to regain a range of motion.

Delay in internal fixation beyond day 5 often leads to the formation of heterotopic bone with marked stiffness. If surgery is delayed the patient should receive Indocid to prevent heterotopic bone formation. If heterotopic bone develops and blocks motion it should be resected early. One should not delay until the alkaline phosphatase and the bone scans return to normal.

Supracondular fractures in the elderly present special problems since they defy attempts at reduction and stable fixation. As a result many elderly patients, whether operated or not, end up with poor and painful elbow function. To prevent these therapeutic disasters recently primary total elbow arthroplasty has been used as a primary form of treatment. Bernard Morrey published encouraging early results of elderly patients with supracondylar fractures treated primarily with the semi-constrained Coonrad Morrey prosthesis. Since then this rationale has been adopted by a number of trauma centers and there are numerous multicenter trials underway to evaluate this form of treatment and place it in its proper perspective.

Open supracondylar fractures present a special problem. If they occur in young patients with good bone and if they are reconstructible, then after a thorough irrigation and debridement a primary open reduction and internal fixation should be carried out. If stable fixation is not possible one should carry out an open reduction and fixation of the articular component, and span the elbow with an external fixator. Once a stable and closed soft tissue envelope has been achieved one can carry out a delayed reconstruction of the metaphyseal component. This greatly reduced risks of infection. In elderly patients with osteoporotic bone this may not be possible as indicated. Every open fracture must be irrigated and debrided. Stable internal fixation greatly lessens the risk of infection. Because of poor bone mobilization of the joint in these patients must be delayed and the internal fixation often supplemented with external fixation to prevent fixation failure. A primary arthroplasty should not be considered because of the risk of sepsis.

In young patients with good bone with Type C1 and C2 fractures 80–90% of good functional results are to be expected. C3 fractures particularly if open and fractures in the elderly, except those treated with primary arthroplsty, lead to unsatisfactory outcomes.