Ligament Reconstruction

65 Ligament Reconstruction

Indications

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

Also indicated for persistent instability after thumb CMC joint dislocation

Technique

Plan incision along the dorsoradial aspect of the thumb at the junction between the glabrous and dorsal hair-bearing skin. Incision begins at midportion of the thumb metacarpal and extends to wrist crease. Extend the incision along the flexor carpi radialis (FCR) tendon for 2 cm (Fig. 65-1).
Protect sensory branches of the radial and lateral antebrachial sensory nerves. Ligate the superficial branch of the radial artery. Avoid the palmar cutaneous branch of the median nerve.
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 on the thumb.
Open the FCR tendon sheath at the wrist and isolate the tendon. Follow the tendon in a distal direction. Incise the transverse fascial fibers that form a separate fibro-osseous canal for the FCR tendon. Trace the tendon beneath the crest of the trapezium to its insertion point on the second metacarpal. Removal of a portion of the crest facilitates this dissection (Fig. 65-2).
Isolate the first dorsal extensor compartment. Retract the tendons in a radial direction. Identify the extensor pollicis longus tendon and retract in an ulnar direction. Select a location between the tendons about 1 cm distal to the joint and perpendicular to the nail bed. This point serves as the initiation point for the bony channel created through the metacarpal base.
Drill a small extra-articular bone tunnel from the dorsum of the metacarpal (perpendicular to the nail bed) to the volar beak of the metacarpal. Progressively enlarge the hole by using sequential drill bits. Make the drill large enough to accept one half of the FCR tendon. Curette any remaining bone within the channel (Fig. 65-3).
Harvest the radial half of the FCR tendon 6 cm proximal to the wrist to the base of the index metacarpal. Multiple techniques are available for tendon harvest. Two transverse incisions (3 and 6 cm proximal to the wrist) allow safe harvest with minimal scarring (Fig. 65-4).
Pass the free end of the harvested tendon graft through the drill hole from volar to dorsal. A tendon passer eases passage of the tendon. Fully reduce the thumb CMC joint and seat the metacarpal against the trapezium. Hold reduction with a percutaneous 0.045 in. wire inserted from the dorsoradial aspect of the thumb metacarpal into the second metacarpal or carpus. Angle wire from distal to proximal during insertion (Fig. 65-5).
Draw the tendon taut and place a suture between the tendon and dorsal periosteum of metacarpal. Route the tendon in a radial direction across the dorsal capsule of the CMC joint and beneath the first dorsal compartment. Pass the tendon around the remaining FCR tendon and back to the radial margin of the trapezium. Suture tendon to metacarpal periosteum.
Repair the origin of the thenar musculature back to the metacarpal. Close the subcutaneous tissue and skin.