When the elbow joint must be sacrificed, an elbow disarticulation is preferable to a more proximal amputation. Not only is greater length preserved, but also the broad flare of the remaining humeral condyles enhances prosthetic fitting and allows humeral rotation to be transmitted to the prosthesis.
Equal anterior and posterior skin flaps are created beginning at the level of the humeral epicondyles. The incisions are extended distally 3 cm distal to the tip of the olecranon posteriorly and to a point just distal to the insertion of the biceps tendon anteriorly. The lacertus fibrosis is identified and divided, which allows the flexor-pronator origin to be freed from the medial epicondyle and exposes the neurovascular bundle underneath. The brachial artery is isolated, doubly ligated, and divided proximal to the joint line. Located medial to the brachial artery, the median nerve is drawn distally, transected as proximally as possible, and allowed to retract into the proximal wound.
The ulnar nerve is identified posterior to the medial epicondyle and is transected in a similar manner. The biceps and brachialis tendons are freed from their insertions on the radius and ulna, respectively. Within the interval between the brachialis and brachioradialis, the radial nerve is identified and transected (as above). The extensor musculature is divided transversely, approximately 7 cm distal to the joint line. Although the skin flaps are approximately equal, the posterior muscle flap remains longer than the anterior muscle flap in order to wrap around and cushion the end of the humerus.
To complete the disarticulation, the anterior capsule and posterior fascia near the level of the olecranon tip are divided, the radiohumeral and ulnohumeral capsules are divided posteriorly, and the forearm is removed. The articular surface of the humerus is left intact. The posterior flap should be carried medially and anchored to the remaining soft tissues on the medial epicondyle. Using additional sutures through the muscle flap and adjacent periosteum, all bony prominences and exposed tendons at the end of the humerus should be covered. In patients with very little subcutaneous tissue and muscle, covering the end of the humerus with a reflected flap of brachialis, biceps, or triceps may be advisable. Because of the flare of the humeral condyles, the distal stump should be expected to be somewhat more bulbous than it is for amputations above the elbow.
An article from Brazil suggests a new surgical procedure to fit electric elbow prostheses to an elbow disarticulation. Normally, the bulky motor hangs several centimeters below the contralateral elbow, causing a cosmetic problem. The authors suggest a shortening osteotomy through the supracondylar area, thus accommodating the prosthetic motor and preserving the condylar flares.