Endoscopic carpal tunnel release: results with special consideration to possible complications

Single-portal endoscopic carpal tunnel release (Agee technique) was carried out in 148 patients. Of these, 100 were examined clinically and electrophysiologically 1 day before surgery and 1 and 3 months thereafter. Ten patients experienced transient ulnar neuropraxia and two patients complained postoperatively of intense pain in the middle and ring fingers. Three patients suffered residual symptoms. In one of these an incomplete release of the distal portion of the retinaculum flexorum was suspected and later confirmed by magnetic resonance imaging. Another patient had applied for pension due to problems associated with a vertebral fracture in addition to his carpal tunnel symptoms. A third patient with residual symptoms was rheumatic, and upon reexamination 6 months later he was virtually symptom free. Five of the 148 operations were converted to an open procedure due to poor visualization. A review of literature on carpal tunnel release (biportal Chow technique and uniportal Agee technique) uncovered 31 intra- and postoperative complications, including 14 affecting nerve structures, 2 tendon structures, 2 bony structures, and 9 the surrounding tissues. We discuss the most common complications, considering in particular the anatomical characteristics in the carpal tunnel region.