Patient Preparation and Positioning

The procedure is done in two phases: an open procedure to excise the scaphoid and then a fully arthroscopic procedure to carry out the arthrodesis. An open technique is used for the scaphoidectomy because excision is faster than when performed arthroscopically, although the final result is the same. The arthroscopic phase of the procedure is performed with the arm secured to an arm board and traction applied along the hand axis with an atraumatic hand holder.

Scaphoidectomy

Only a plain distal lateral volar incision over the scaphoid tubercle is needed ( Fig. 27.1 ). This incision can be either horizontal or longitudinal. The volar scaphotrapezial ligaments are always more difficult to cut if a dorsal approach is used. After cutting these ligaments, a bone rasp and spatula can be used to excise all or part of the scaphoid.

In patients with scapholunate (SL) ligament injury sequelae, the SL ligament is torn and the entire scaphoid fossa of the radius is arthritic. The scaphoid is removed as a single piece. In patients with scaphoid nonunion sequelae, only the radial styloid is arthritic; the segment of the scaphoid fossa of the radius across from the pole will be intact. The proximal pole remains attached to the lunate by the SL ligament. In these patients, only the distal part of the scaphoid is removed ( Fig. 27.2a, b ). The incision is reclosed layer by layer ( Fig. 27.3a, b ). Grafts can be harvested from the resected scaphoid.

Exploration of Radiocarpal Joint

Traction is placed on the wrist using an atraumatic hand holder and 5 to 7 kg of counterweight. The 3–4 portal is used to explore the radiocarpal joint. The main purpose is to inspect the lunate fossa of the radius and assess the quality of the lunate cartilage.

In stage III SNAC wrists, the proximal pole of the scaphoid and the cartilage across from the scaphoid fossa of the radius must also be inspected. At this point, a styloidectomy may be needed (Chapter 6). If so, a bur is introduced through the 1–2 portal to resect the radial styloid process without disturbing the volar and dorsal attachments of the extrinsic ligaments (dorsal radiocarpal and radioscaphocapitate).