A muscle-splitting approach to the ulnar collateral ligament of the elbow. Neuroanatomy and operative technique.

The standard surgical approach for repair or reconstruction of the ulnar collateral ligament of the elbow involves lifting off of the tendon of the common flexor bundle at its origin on the medial epicondyle. However, a more limited muscle-splitting approach may be feasible. A muscle-splitting approach is less traumatic to the flexor-pronator muscle mass, and it could decrease operative time and lessen immediate morbidity after surgery. A proposed muscle-split through the common flexor bundle extends from the medial humeral epicondyle to a point distal to the tubercle of the ulna such that repair or reconstruction can be performed on the ulnar collateral ligament. To examine the feasibility of this approach, we performed a study combining anatomic dissections with clinical observations. We dissected 15 fresh-frozen adult cadaveric elbows to examine the neuroanatomy of the medial side of the elbow. All pertinent nerves were identified and mapped. From these data, we defined a "safe zone" for a muscle-splitting approach to the ulnar collateral ligament that allows adequate room for repair or reconstruction of the ligament without risking denervation of the surrounding musculature. The safe zone extends from the medial humeral epicondyle to approximately 1 cm distal to the insertion of the ulnar collateral ligament on the tubercle of the ulna. Twenty-two patients with ulnar collateral ligament tears underwent either a direct repair or a reconstruction of the ligament using the proposed muscle-splitting approach. With a minimum followup of 1 year, there was no clinical evidence of muscle denervation. From the combined anatomic study and clinical data, we believe that a less traumatic muscle-splitting approach to the ulnar collateral ligament affords a safe and simple surgical approach for repair or reconstruction of the ligament.