Scapholunate ligament reconstruction

As discussed in Chapter 21 , stage I and II injuries still have good ligament quality after partial or complete injury. Therefore repair should be attempted.

For stage V and VI injuries, where either irreducible malalignment of the carpus (stage V) or cartilage loss with arthritis is present (stage VI), salvage procedures should be pursued ( Chapter 27 Salvage Procedures for Scaphoid Nonunion). Options include proximal row carpectomy, four-corner fusion, or wrist arthrodesis ( Chapter 53 Total Wrist Fusion).

A 6-cm longitudinal incision is designed on the dorsal wrist, ulnar to the Lister tubercle ( Fig. 22.1 ).

After incising the extensor retinaculum between the third and fourth compartments, the extensor pollicis longus (EPL) is identified and retracted radially ( Fig. 22.2 ).

The wrist capsule is opened longitudinally to expose the SL interval.

After exposing the SL interval, scar tissue should be debrided back to healthy bleeding tissue ( Fig. 22.3 ).

If static, reducible instability is present, the scaphoid will need to be anatomically reduced to correct any dorsal intercalated segment instability (DISI) deformity.

Two 0.062-in (1.57-mm) Kirschner wires (K-wires) can be used to reduce the scaphoid and lunate into preinjury anatomic alignment ( Fig. 22.5 ).

Because the scaphoid is flexed and the lunate is extended with a DISI deformity, the K-wires should be placed from distal to proximal in the scaphoid and proximal to distal in the lunate.

Using the K-wire, the lunate should be flexed maximally toward the fingers to ensure that it is neutral with respect to the long axis of the radius.

The scaphoid can be extended to ensure that the flexed, pronated posture is corrected ( Fig. 22.6 ).

To close the gap between the two bones, the wires are compressed.

Reduction is maintained by pinning the scapholunate interval. This can be achieved with one 0.062-in (1.57-mm) K-wire. The entry point for the K-wire is just distal to the radial styloid. The wire should be directed perpendicular to the long axis of the forearm to capture the scaphoid and lunate. Reduction of the scapholunate gap and restoration of the normal scapholunate angle (30–60 degrees) should be confirmed fluoroscopically.

A second 0.062-in (1.57-mm) K-wire can be driven across the scaphocapitate (SC) interval to prevent midcarpal motion ( Fig. 22.7 ).

Using a 5-mm osteotome, create a trough on the dorsal surface of the scaphoid and lunate to accept the BTB graft.

The dimensions of this trough measured 12 mm long, 6 mm wide, and 6 mm deep ( Fig. 22.8 ).

After measuring the defect created in the dorsum of the scaphoid and lunate, transpose this template onto the capitohamate ( Fig. 22.9A–B ).

Using the 5-mm osteotome, harvest the BTB graft ( Fig. 22.10 ).

After contouring and placing the graft in the trough on the dorsum of the scaphoid and lunate, 1.3-mm or 1.5-mm screws can be placed through each side of the graft into the corresponding carpal bone ( Fig. 22.13 ). Alternatively, if precise measurements are obtained, then the graft can be press fit into the trough by gently tapping the bone grafts into the slot with a bone tamp.

The K-wire should be buried and left in place to maintain reduction of the SL interval ( Fig. 22.14 ).

After the tourniquet is deflated and hemostasis is ensured, the dorsal capsule and extensor retinaculum can be closed using 3-0 or 4-0 Vicryl suture.

The skin can be closed using 4-0 Monocryl or 4-0 PDS.