Surgical technique

Regional, axillary block anesthesia is performed and a nonsterile tourniquet is placed. After exsanguination with an Esmarch bandage and inflation of the tourniquet to 250 mmHg, a dorsal incision is made from the base of the thumb metacarpal distally for approximately 3 cm. In the subcutaneous tissue the sensory branches of the radial and lateral antebrachial cutaneous nerves are identified and protected. Subperiosteal exposure is obtained without injuring the extensor pollicis longus, and the TM joint is identified with a 25-gauge needle. One cm distal to the TM joint, near circumferential access around the meta-carpal is obtained in anticipation of the osteotomy. The volar extent of the metacarpal is visualized at this location to facilitate accurate resection of a dorsally based 30° wedge of bone (see Fig. 3). A microsagittal saw is used to score the metacarpal 1 cm distal to its base transversely, but a complete cut through the volar cortex is not made. A new saw blade is left in that partial osteotomy site and a second blade is used approximately 5 mm distal to the first cut at an angle of 30°, so that the two blades intersect at the volar cortex. The wedge of bone is removed, the distal metacarpal is extended and compressed against the proximal fragment, and two 11 x 8 staples are placed (Fig. 4). Typically, the author maintains the reduced position of the metacarpal while my assistant predrills, and then places the staples.

A layered closure of the perisoteum and skin is performed, and overlying thumb spica splint is placed for 10 days. After that time sutures are removed and a thumb spica cast with the in-terphalangeal joint of the thumb left free is placed for an additional 4 weeks. Approximately 6 weeks following surgery, a forearm-based thumb spica orthoplast splint is placed, and the patient is instructed to begin gentle TM motion. Grip and pinch exercises are started at approximately 8 weeks after surgery unless union is delayed.

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