Anatomic study and clinical analysis of anterior interosseous nerve compression syndrome

Abstract

Objective To investigate the anatomic factors that cause anterior interosseous nerve entrapment and analyze the clinical results of decompression. Methods Twelve fresh cadaver upper limb specimens were dissected. The anatomic characteristics of the anterior interosseous nerve and the possible compression factors along its course were observed. Fifteen cases of anterior interosseous nerve compression syndrome were treated between May 1997 and December 2007. One underwent conservative treatment and 14 had surgical decompression of the anterior interosseous nerve. The tendinous structures that compressed the nerve were resected. In 7 cases the vessels that run across the nerve were ligated. Postoperative fo].low up time ranged from 6 months to 4 years. Results Anatomic studies in the dissected 12 specimens showed 91.7% occurrence ( 11specimens) of tendinous structures of the deep head of pronator teres. The anterinor interosseous nerve was almost always sandwiched between the two heads of pronator teres. The tendinous arch of flexor digitorurn superficialis of the index and middle fingers occurred in 41.7% (5 specimens). Accessory head of flexor pollicis longus occurred in 58.3% (7 specimens). The incidence of abnormal vessels across the median nerve and the anterior interosseous nerve was 66.7% (8 specimens). The 7 cases treated with additional ligation of the abnormal vessels running across the anterior interosseous nerve had better results than those treated only with nerve decompression and resection of the tendinous or fibrous structures. Conclusion Anterior interoaseous nerve compression syndrome is the result of multiple factors. All the structures that can cause entrapment of the nerve on its anatomic course should he released in order to achieve satisfactory results. Key words: Nerve compression syndromes; Anatomy, regional; Anterior interosseous nerve