[Lesions of the radial nerve in fractures of the humeral diaphysis. Apropos of 62 cases].

PURPOSE OF THE STUDY: Evaluate outcome of different techniques used for radial nerve repair after humeral shaft fractures. Identify situations where nerve exploration is required or inversely unneeded. Evaluate the risk of more systematic nerve exploration in case of radial nerve palsy.

MATERIAL AND METHODS: Over a 10 year period, we cared for 62 patients with humeral fractures associated with radial nerve palsy who were addressed directly to our unit or referred after prior care. There were 54 men (mean age 30 years, 17 - 66) and 8 women (mean age 40 years, 19 - 80). There were 40 fractures of the mid-third and 22 fractures of the distal third of the humerus. Anatomic severity varied although most fractures were displaced or subsequent to high-energy trauma. Orthopedic treatment was used alone in 14 cases. There were 6 plate fixations and 42 intramedullary nailings. Twenty-four of the 62 cases of radial nerve palsy resulted from nerve tears but a continuous nerve was found in 38 cases. Tears were treated by primary suture (n =4), secondary graft (n =17, 5 with 2 torons and 12 with 3 or 4 torons), or primary muscle transfer (n =3). Neurolysis was used in 6 of the 38 cases with continuous nerve. Motor outcome was assessed using composite criteria taking into account the physiological role of each muscle group.

RESULTS: All primary sutures gave excellent results. Excellent or good outcome was achieved in 12 of the 17 secondary grafts although a complementary transfer was required in 2 cases. Conversely, outcome was average in 2 cases and a failure in 3. Outcome depended on the length of the graft and the number of torons used. The importance of a proximal resection in healthy tissue sometimes required a complementary medial access and a graft between the biceps and the brachialis. Recovery was achieved in 37 of the 38 lesions with continuous nerve including 31 cases which did not require a second procedure.

DISCUSSION: In case of nerve rupture, the outcome of primary suture appears to be better than that of secondary grafts. The success of the graft depends on the length of the tissue loss after sectioning in healthy tissue and on the number of torons used. This difference in prognosis points out the usefulness of systematic exploration in order to use primary or early direct suture in cases of high-energy displaced fractures. Minimally displaced fractures often are accompanied by a simple contusion with spontaneous recovery. However, in intermediary cases, the decision to make a systematic nerve exploration during the osteosynthesis procedure (aimed at early mobilization) is based on the fact that recovery was achieved in 23 cases in which initial exploration of a continuous nerve has been performed. Indirectly, the favorable outcome of postoperative paralyses reported by several authors, also supports this policy.