Open Reduction and Internal Fixation Lunate Dislocation via Combined Dorsal–Palmar Approach

40 Open Reduction and Internal Fixation Lunate Dislocation via Combined Dorsal—Palmar Approach

Indications

Incomplete closed reduction, percutaneous fixation
Failed closed reduction and percutaneous fixation
Some authors recommend early open reduction, Kirschner wire fixation, and ligament repair in all lunate dislocations, regardless of the reduction achieved by closed means. Anatomical reduction by closed means is rare because residual carpal instability usually persists.

Technique

Make a longitudinal incision over the third to fourth extensor compartment (Fig. 40-1).
Incise the extensor retinaculum obliquely.
Raise a V-shaped flap in the capsule preserving the dorsal intercarpal ligament and dorsal radiolunatetriquetral ligament.
Expose the palmar capsule using an extended carpal tunnel approach (Fig. 40-2).
Retract the flexor tendons and the median nerve radially. This will reveal the palmarly dislocated lunate and a transverse rent in the capsule (Fig. 40-3).
From the palmar approach the lunate is reduced by manual pressure with gentle longitudinal traction on the wrist (Fig. 40-4).
Place Kirschner wires into the scaphoid (S) and lunate (L) to use as joysticks to reduce the scapholunate (SL) joint. The scaphoid-lunate relationship is restored when the diastasis is reduced and the head of the capitate (C) is contained by the lunate articulation. Kirschner wires are placed across the reduced SL and scaphocapitate articulation.
Repair the dorsal ligaments. If there is insufficient ligament to suture to, suture anchors are placed in divergent orientations and the ligament is repaired. In rare instances with intersubstance tears a flap of dorsal intercarpal ligament can reinforce the dorsal SL ligament (Fig. 40-5).
Use Kirschner wires as joysticks to reduce the lunotriquetral (LT) joint and fix it with divergent percutaneous K-wires. Repair the LT ligament if possible. Repair the dorsal ligaments (Fig. 40-6).
Close the dorsal capsule but do not overly tighten.
Verify anatomical reduction of the lunate via mini image and repair the palmar rent in the capsule with no. 0 nonabsorbable sutures.
Close the retinaculum with Z-lengthening.