ANALYSIS OF TARDY ULNAR NERVE PALSY ASSOCIATED WITH CUBITUS VARUS DEFORMITY AFTER A SUPRACONDYLAR FRACTURE OF THE HUMERUS - A REPORT OF 4 CASES

Four cases of tardy ulnar nerve palsy associated with a cubitus varus deformity of the elbow secondary to a supracondylar fracture of the hu merus are presented. All patients had surgical management of their uln ar nerve palsy, In two patients, the ulnar nerve was entrapped by scar tissue at the abnormal position and the nerve developed a sharp V-sha ped kink when the elbow was flexed. In one patient, the ulnar nerve di splaced anteriorly with elbow flexion and spontaneously reduced into t he ulnar nerve groove with elbow extension. In one patient, the ulnar nerve remained in the ulnar nerve groove; however, it was entrapped by fibrous bands arising from the flexor carpi ulnaris. It is speculated that malunion resulting in cubitus varus deformity will alter the ana tomy at the elbow and that this can have a direct effect on the positi on and instability of the ulnar nerve. Incongruity of the elbow joint due to cubitus varus deformity also may cause osteoarthritic changes. As a result, ulnar neuropathy may develop from irritation to the ulnar nerve from the posttraumatic osteoarthritic changes at the elbow join t.