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 uln ar collateral ligament of the elbow involves lifting off of the tendon of the common flexor bundle at its origin on the medial epicondyle. H owever, a more limited muscle-splitting approach may be feasible. A mu scle-splitting approach is less traumatic to the flexor-pronator muscl e mass, and it could decrease operative time and lessen immediate morb idity after surgery. A proposed muscle-split through the common flexor bundle extends from the medial humeral epicondyle to a point distal t o the tubercle of the ulna such that repair or reconstruction can be p erformed 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 cadaver ic 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 c ollateral ligament that allows adequate room for repair or reconstruct ion of the ligament without risking denervation of the surrounding mus culature. The safe zone extends from the medial humeral epicondyle to approximately 1 cm distal to the insertion of the ulnar collateral lig ament on the tubercle of the ulna. Twenty-two patients with ulnar coll ateral ligament tears underwent either a direct repair or a reconstruc tion of the ligament using the proposed muscle-splitting approach. Wit h a minimum followup of 1 year, there was no clinical evidence of musc le 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 re pair or reconstruction of the ligament.