Patient Preparation and Positioning

The procedure is performed under regional anesthesia. The patient’s arm is secured to the table. Upward traction can be placed either on the long fingers or on the thumb alone. If traction is placed on the thumb, only 2 to 3 kg of counterweight is needed and if traction is placed on the long fingers, 5 to 6 kg of counterweight is needed.

Midcarpal Joint Debridement

This procedure requires only a midcarpal joint approach. The ulnar midcarpal (MCU) portal is the most straightforward entrance to the joint. A shaver is introduced through the radial midcarpal (MCR) portal to debride the joint. The scope and shaver positions are then reversed to finish the midcarpal joint debridement.

Scaphotrapeziotrapezoid Joint Exploration

The STT joint can be easily examined with the scope in the MCR portal. From the midcarpal joint, the medial and distal faces of the scaphoid are followed while the scope passes between the scaphoid and the capitate ( Fig. 22.1 ). When the scope reaches the STT joint, the view may be hindered by widespread synovitis. The joint must first be cleaned out through the 1–2 or STT portal. A needle is inserted between the first and second compartments, ~1.5 cm below the trapeziometacarpal joint. Because this joint is straight, the natural angulation of the carpal bones is not a factor as it is when the positions of other portals are determined. The scope is held stationary and used to find the needle tip inside the joint ( Fig. 22.2 ).

A small horizontal incision is made. Mosquito forceps are used to pass through the capsule, and the shaver is inserted into the joint. Synovectomy is performed until the entire joint is completely debrided; any small cartilage fragments are also removed ( Fig. 22.3 ).

Distal Resection of the Scaphoid

A bur is introduced into the 1–2 portal. The tubercle on the distal pole is resected under visual control, starting at its dorsal section and gradually proceeding toward its volar section ( Fig. 22.4a, b ). The resection must be uniform. It is also important to ensure that no bone lip remains, especially on the medial portion against the capitate ( Fig. 22.5 ). When the resection is properly carried out, the scope (2–3 mm), which is still in the MCR portal, can easily be moved into the STT joint. Nevertheless, it is easier to directly inspect the quality of the resection through the 1–2 portal ( Fig. 22.6 ).