Functional outcome of tardy ulnar nerve palsy manifests after 25 years due to nonunion of lateral epicondyle left humerus treated by ulnar nerve transposition: A case report.

INTRODUCTION: Tardy ulnar nerve palsy is a chronic clinical condition characterized by delayed-onset ulnar neuropathy.

CASE PRESENTATION: Male 36 years old with 5 years clawing left ring and little finger, weakness of intrinsic muscle and grip, and paresthesia on ulnar nerve distribution. There was a history of elbow trauma 30 years ago. The radiological finding is a non-union of the lateral condyle without significant valgus. Intraoperatively, an intact ulnar nerve was discovered with no significant fibrous tissue. The author performed anterior transposition of the ulnar nerve. After 6 months, there is improvement in power and sensibility, with the quick dash score decreasing from 18 to 6.

DISCUSSION: Any increase in a valgus deformity at the elbow joint would lead to stretching of the nerve resulting in neuropraxia. On this case we found there is slight valgus deformity, but there is malunion of lateral epicondyle that causes incongruency of elbow joint that will lead to chronic impingement ulnar nerve. The patient work as officer working in front of computer typing for hours and sometimes lifting heavy objects. These activities irritate ulnar nerve on incongruent joint which causes tardy ulnar nerve palsy. The treatment of choice is ulnar nerve transposition.

CONCLUSION: The treatment of choice is anterior ulnar transposition. Any condition that impairs the anatomical structure of the elbow joint can cause ulnar nerve palsy. From this case, we also learn that it is not necessary to correct bone deformity or stabilize the non-union condyle if there is no significant deformity.