Capitate Shortening with Capitohamate Fusion

57 Capitate Shortening with Capitohamate Fusion

Indications

Symptomatic Kienböck disease without lunate (L) collapse (stages 0, I, or II) in a wrist with neutral or positive ulnar variance.

Technique

Longitudinal dorsal incision that begins just ulnar to Lister’s tubercle and extends to the base of the third metacarpal

Protect the radial sensory nerves and lateral antebrachial cutaneous branches using loupe magnification. Elevate flaps at the level of the extensor retinaculum.

The extensor pollicis longus (EPL) tendon is identified and the third compartment opened. The EPL tendon is transposed in a radial direction from the third compartment.

The second compartment is elevated in a radial direction and the fourth compartment in an ulnar direction. The posterior interosseous nerve is located under the fourth compartment and resected.

A longitudinal capsulotomy is performed to expose the underlying radiocarpal and midcarpal joints. The capsule may have to be elevated from the radius (inverted T capsulotomy) for adequate carpal exposure (Fig. 57-1).
The capitate (C) and hamate (H) are exposed by capsular elevation. A capitate shortening (2–4 mm) is desegned at the level of the distal articular surface of the scaphoid (S).
A thin osteotome is used to remove a wafer of bone from the capitate via two parallel cuts. The osteotome is driven partially through the capitate during the first cut and completely for the second. The osteotome is then replace into the first cut and the osteotomy completed followed by removal of the intervening bone fragment (Fig. 57-2). The volar capsule is not disrupted.
The mobile capitate head is reduced onto the distal fragment using an elevator placed into the midcarpal joint. Two 0.045 in. or 0.062 in. wires are placed across the osteotomy site in a crossed configuration (Fig. 57-3).
The articular and subchondral surfaces between the capitate and hamate are removed using curettes, rongeurs, and osteotomes (Fig. 57-4).
Two percutaneous 0.045 in. or 0.062 in. Kirschner wires are placed across the capitohamate joint. Bone graft is harvested from the distal radius. Cancellous bone graft is packed into the depths of the fusion site within the denuded capitohamate surfaces (Fig. 57-5).
Verify pin placement using minifluoroscopy and make necessary adjustments. Pins are usually cut beneath the skin.
The capsule is reapproximated and standard closure is performed and the EPL tendon is transposed dorsal to its compartment.