Innervation of the supinator muscle and its relationship to two‐incision distal biceps tendon repair: An anatomic study

Abstract

Reinsertion of the ruptured distal biceps tendon has been performed using either a single-anterior incision or a two-incision approach. A systematic review of these two repair methods has identified a higher incidence of supination weakness following the two-incision approach. The objective of this study was to describe the innervation of the supinator muscle and its implications regarding a two-incision distal biceps repair. Twelve fresh upper extremity specimens from 12 males were dissected with the forearm in full pronation. The number of branches of the posterior interosseous nerve (PIN) to the supinator, their site of exit from the PIN trunk, and their distance from a variety of known anatomic landmarks were recorded. Specimens were characterized as high (<5 mm), moderate (6-10 mm), or low (>10 mm) risk of nerve branch injury depending on the proximity of nerve branches to the bicipital tuberosity. In general, we found the innervation of the supinator to be highly variable. There were from two to nine branches of the PIN which supplied the supinator, with 0-3 arising from the ulnar side of the nerve. Four specimens were at low, five at moderate, and three at high risk of nerve branch injury during dorsal exposure of the bicipital tuberosity. We conclude that there is a substantial amount of variability in the innervation of the supinator, with certain patterns being at higher risk of nerve branch injury if dissection of the supinator is carried out over the bicipital tuberosity.

Acute distal biceps rupture in an adolescent weightlifter on chronic steroid suppression: a case report

“…Chavan et al [9] meta-analysis reported a significant increase in unsatisfactory results with a twoincision approach (31 vs. 6% in the single-incision group), mostly because of loss of forearm rotation or supination strength. It is believed that this was caused by robust dissection between the radius and the ulna, leading to denervation or damage of the supinator [18,19]. Complication rates were similar between the two groups (18% in the single-incision group vs. 16% in the twoincision group); however, the single-incision group had a higher rate of nerve injury (12%) whereas the twoincision group had more loss of forearm rotation (9%).…”

Dynamic rotational alteration in positional relationship of neurovascular structures and distal biceps tendon insertion: a cadaveric study

“…The NV anatomy of the cubital fossa is complex and variable, and various studies have described anatomical patterns without surgically useful reference points 4 12–15. Extensive dissection of these structures is often not performed in most surgical procedures, and iatrogenic NV injury is possible 5 10 11 16.…”

Reconstruction after Distal Biceps Tendon Rupture

“…40 Partial denervation of the supinator muscle during the two-incision approach could be an explanation for this common complication. Duquin et al 41 found that, in 25% of their specimens, at least one nerve branch runs close to the radial tuberosity when the forearm is in pronation (as is the case during two-incision approach).…”