Arthroscopic distal hemitrapeziectomy versus open hemitrapeziectomy without interposition in osteoarthritis of the first CMC joint

Arthroscopic distal hemitrapeziectomy versus open hemitrapeziectomy without interposition in osteoarthritis of the first CMC joint

We hypothesize that compared to open surgery, arthroscopic intervention results in:
1. earlier postoperative functional recovery
2. Less chance of damaging the superficial branch of the radial nerve
3. Less postoperative pain

6 weeks, 3, 12 and 24 months

1. Arthroscopic hemitrapeziectomy
The procedure is performed under regional or general anaesthesia. Tourniquet control is applied, the thumb held in longitudinal traction. Traction applied to the thumb is 3-5 kg. The CMC joint is identified with palpation and a needle insertion. Small incisions are made on the radial and ulnar side (1U and 1R [ref]) of the EPB. With small scissors and blunt clamp the joint capsule is perforated and the 1.9 mm or 2.3 mm 30 degrees arthroscope is introduced. After identification, the joint is debrided and a synovectomy is performed using the 2.3 shaver. The hemitrapeziectomy is performed with the burr (2.6 or 3.9 mm), debriding the sclerosed surface of the distal trapezium for about two to three mm. The instruments and arthroscope are changed from portals to achieve adequate resection. Debris is rinsed out and the instruments are removed.

2. Open trapeziectomy
The procedure is performed under regional or general anaesthesia. Tourniquet control is applied, with the arm on an arm rest. According to the surgeon a volar Wagner incision or a dorsal incision is made. Branches of the superficial radial nerve are identified and retracted. The CMC joint is opened, hereby creating a capsule flap which is closed at the end of the procedure. The trapezium is removed using an oscillating saw, osteotome and rongeur in a piecemeal technique. Special attention is given to osteophytes around the CMC I joint (if present, between first and second metacarpal). Care is given not to damage the FCR tendon. Afterwards debris is rinsed out and the capsule is closed with resorbable braided sutures. Skin is closed with nonabsorbable nylon suture.

Rehabilitation
In both groups, directly postoperatively, the thumb is immobilised in a fore arm splint, with only the interphalangeal joint free to move. The splint is changed at the first outpatient visit two weeks later and a thumb spica cast is applied for an additional four weeks. After removal of the cast a hand therapy regime is started and full motion is allowed. Full power and sport can be a resumed at 12 weeks postoperative.