Morphological and neurophysiological impairment of the nerve in type II macrodactyly
Fig 2
Median nerve damage and compensatory communication branch from ulnar nerve (BA type) in macrodactyly, which was investigated by electromyogram.
(A to D) Median nerve damage. In a typical patient without a communication branch from the ulnar nerve to the median nerve, the median nerve was stimulated and showed a prolonged latency and decreased amplitude of electrophysiological signals in the digital nerve of the second finger (A) before surgery and (B) during surgery. Simultaneously, when the median nerve was stimulated, no electrophysiological signals were recorded in the digital nerve of the second finger (C), which suggested no compensatory communication branch from ulnar nerve to median nerve. When the ulnar nerve was stimulated, a normal electrophysiological signal was recorded in the digital nerve of the fifth finger (D). (E to H) Berrettini anastomosis (BA) type. In a typical patient with a communication branch from the ulnar nerve to the median nerve, when the median nerve was stimulated a prolonged latency and decreased amplitude of electrophysiological signals were recorded in the digital nerve of the second fingers before surgery (E) and during surgery (F). Simultaneously, when the ulnar nerve was stimulated, a significant electrophysiological signal was recorded in the digital nerve of the second finger (G), which suggested a compensatory communication branch from the ulnar nerve to the median nerve. We stimulated the ulnar nerve and recorded a normal electrophysiological signal in the digital nerve of the fifth fingers (H).