Patient Preparation and Positioning

The procedure is performed under regional anesthesia. The patient’s arm is secured to the arm board. An atraumatic hand holder is used to apply 5 to 7 kg of traction along the arm’s axis.

Debridement and Exploration of the Radiocarpal Joint

The radiocarpal joint is typically affected by significant synovitis, often with accompanying bone and cartilage fragments. The sheath and arthroscope are inserted through the 3–4 portal. The shaver is inserted in the 6R portal to start debriding the medial side of the radiocarpal joint. The synovectomy is completed after reversing the position of the scope and shaver. All cartilage fragments must be removed.

Expanded Styloidectomy

The scope can be placed in either or both the 3–4 and the 6R portals. The joint assessment will often reveal that no cartilage remains on the scaphoid fossa of the radius or on the proximal pole of the scaphoid ( Fig. 26.2 ). All other cartilage surfaces will be intact.

After locating the 1–2 portal with a needle, the shaver is inserted to complete the synovectomy around the radial styloid process. A bur is used to perform the styloidectomy as in a typical arthroscopic styloidectomy procedure ( Fig. 26.3 ) (Chapter 6). The styloid is resected at an angle while preserving the volar and dorsal attachments of the extrinsic ligaments (dorsal radiocarpal and radioscaphocapitate).

The entire scaphoid fossa is then resected until vascularized subchondral bone is exposed (~2–3 mm or roughly the size of the bur). This bleeding bone will help ensure the success of the interposition arthroplasty by creating conditions favorable to fibrosis. After the styloidectomy, a suture anchor is introduced through the 1–2 portal and inserted into the tip of the styloid process under arthroscopic control ( Fig. 26.4a, b ). The anchor’s sutures are externalized by the 1–2 portal and will be used to secure the tip of the V-shaped interposition implant.

Stabilization of the Scapholunate Joint

Repairing the SL ligament is unrealistic at this point; nevertheless, dorsal capsule-to-ligament suture repair (Chapter 15) can be carried out to stabilize the SL joint and avoid further damage. This is performed using the same technique as is used for SL ligament repair in less advanced SLAC patients. It is rare to find the dorsal SL ligament stump still attached to the scaphoid.

The following technical trick can be used instead. A 1.2 mm K-wire is inserted through the 3–4 portal as vertically as possible. The scope, in the 6R portal, is used to follow the dorsal recess and verify the proper K-wire position in the posterior horn of the proximal pole of the scaphoid. The K-wire creates a small bone tunnel in this proximal pole ( Fig. 26.5 ). A needle with one suture is passed through the tunnel and retrieved in the midcarpal joint; the other suture is placed in the SL stump on the lunate ( Fig. 26.6 ). Suturing is then carried out as typically done for SL repair. The final phase of the dorsal capsule-to-ligament repair will be carried out at the end of the procedure.