Metacarpal Osteotomy

67 Metacarpal Osteotomy

Indications

Mild to moderate painful thumb carpometacarpal (CMC) joint arthritis recalcitrant to nonoperative management

Technique

Incision along the dorsoradial aspect of the thumb at the junction between the glabrous skin of the palm and dorsal hair-bearing skin. Incision begins at mid-portion of the thumb metacarpal and extends to wrist crease (Fig. 67-1).
Protect sensory branches of the radial and lateral antebrachial sensory nerves.
Elevate the thenar muscles in an extraperiosteal fashion from the thumb metacarpal and CMC joint. Identification of the CMC joint is facilitated by longitudinal traction to the thumb (Fig. 67-2).
Isolate the first dorsal extensor compartment. Retract the abductor pollicis longus (APL) tendon in a radial direction and the extensor pollicis brevis (EPB) tendon in a radial direction.
Place subperiosteal reverse retractors around the thumb metacarpal ~1 cm distal to the CMC joint. Prepare wedge resection with apex based along volar aspect of metacarpal and base along the dorsal cortex.
Cut bone parallel to joint surface using a fine-bladed microsagittal saw. Do not cut completely through the bone. Make second cut ~5 mm distal to the first cut to delineate a 30 degree wedge of bone. Do not violate volar cortex (Fig. 67-3).
Remove the wedge of bone and crack the remaining volar cortex. Reduce the osteotomy site until the triangular defect closes. Obtain provisional fixation with a 0.045 in. wire (Fig. 67-4).
Add additional fixation using another wire, interosseous wiring, or a small plate and screws. Verify position of internal fixation using fluoroscopy.
Repair the origin of the thenar musculature to the metacarpal using absorbable suture. Close the subcutaneous tissue and skin.