The “Sign of Horns” deformity following the Thompson’s approach to the proximal radius—A rare case report and literature review

The Thompson’s approach is used as the standard posterior approach by many surgeons. Although posterior interosseous nerve palsy following the Thompson’s approach has been reported by several authors, isolated paralysis of the extensor digitorum communis (EDC) is a rare occurrence. We report to you a case of isolated paralysis of EDC following the Thompson’s approach in a 14-year-old boy who recovered completely on the 5th postoperative day. Each of the approaches to the proximal radius poses a risk of damage to the posterior interosseous nerve and its branches because of traction. Damage may occur during exposure or implant insertion. Any surgery around the supinator and the radial tunnel region is dangerous because of complex anatomy, lack of intermuscular planes and varying distribution of the radial nerve. Avoiding excessive posterior or ulnar retraction of the EDC and improper dissection can avoid the “sign of horns” deformity following the Thompson’s approach.