Indirect decompression of the carpal tunnel during basal joint arthroplasty of the thumb

In patients having basal joint arthroplasty, rates of concomitant carpal tunnel syndrome may exceed 43%. Excision of the trapezium during basal joint arthroplasty partially releases the transverse carpal ligament. The objective of this study was to determine whether indirect release of the remaining fibers of the ligament at its insertion on the scaphoid tubercle through the same incision would adequately decompress the carpal canal. This would avoid the morbidity of a second incision.

We retrospectively reviewed 10 consecutive patients treated over a 2-year period who had concurrent ligament reconstruction, tendon interposition basal joint arthroplasty of the thumb with complete trapezial resection, and indirect carpal tunnel release through a single incision. Self-reported postoperative pain relief was documented. Preoperative and postoperative evaluations of light touch sensibility, Tinel's sign, Phalen's test, median nerve compression test, and Weinstein Enhanced Sensory Test monofilament testing were analyzed. All patients had preoperative electrodiagnostic testing.

At mean 12 month follow-up (range, 5-35 months), numbness and paresthesias resolved in all cases: 9 patients had good or excellent pain relief and 1 reported fair pain relief despite transient postoperative reflex sympathetic dystrophy. Tinel's, Phalen's, and median nerve compression tests were each positive in 9 patients preoperatively and 0 patients postoperatively. Diminished light touch sensibility was present in 7 preoperatively and 1 postoperatively. WEST monofilament thresholds improved postoperatively in 8 patients. These improvements were statistically significant. One patient had postoperative nerve conduction studies performed to evaluate an ulnar nerve lesion at the elbow; the preoperative median nerve abnormalities had normalized.

Carpal tunnel syndrome can be successfully managed with indirect release of the transverse carpal ligament during basal joint arthroplasty, thus avoiding a second incision, reducing operating time, and potentially reducing the possibility of perineural adhesions, recurrent motor branch injury, palmar cutaneous nerve damage, weakness, stiffness, and pillar pain.

Therapeutic IV.