Tardy Ulnar Nerve Palsy.

Tardy ulnar nerve palsy is a chronic clinical condition characterized by a delayed onset ulnar neuropathy after an injury to the elbow. Typically, tardy ulnar nerve palsy occurs as a consequence of nonunion of pediatric lateral condyle fractures at the elbow, which eventually lead to a cubitus valgus deformity. While the child grows, the deformity worsens and the ulnar nerve is gradually stretched until classic symptoms of ulnar nerve neuropathy appear. Other childhood elbow trauma has also been associated with tardy ulnar nerve palsy, including supracondylar fractures resulting in cubitus varus, fractures of the medial condyle and of the olecranon, as well as radial head or Monteggia fractures/dislocation, with or without deformity. The clinical assessment includes obtaining a complete history, physical examination, nerve conduction tests, and elbow imaging studies. Treatment consists of ulnar nerve decompression, with or without corrective osteotomy, with overall successful results usually achieved.