Ligament Reconstruction with Tendon Interposition

69 Ligament Reconstruction with Tendon Interposition

Indications

Moderate to severe painful thumb carpometacarpal (CMC) joint arthritis recalcitrant to nonoperative management. Considerable joint degeneration precludes metacarpal osteotomy or ligament reconstruction without tendon interposition.

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 travels to wrist crease. Extend the incision along the flexor carpi radialis (FCR) tendon for 2 cm (Fig. 69-1).
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 to 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 or the FCR tendon. Trace the tendon beneath the crest of the trapezium to its insertion point on the second metacarpal. Remove the crest to ease tendon dissection. Retract the tendon in an ulnar direction (Fig. 69-2).
Expose the articulations about the trapezium by a U-shaped capsulotomy based at the thumb metacarpal. Incise the capsule sharply and elevate it from the trapezoid and scaphoid. Visualize the scaphotrapeziotrapezoid (STT) and CMC joints. Mobilize the entire trapezium by sharp dissection around its borders. Do not stray from the bone because the radial artery, adjacent tendons, and superficial nerves are in close proximity (Fig. 69-3).
Divide the trapezium into a radial and ulnar half using an osteotome. Remove each section by sharp dissection and upward traction. Protect the FCR tendon during extirpation of the ulnar section (Fig. 69-4).
Elevate the thumb metacarpal base from the wound and remove peripheral rim osteophytes with a rongeur. Inspect the scaphotrapezoid joint for degeneration. Remove any degenerated trapezoid by osteotomy using an osteotome or bur (Fig. 69-5).
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 bone tunnel from the dorsum of the metacarpal (perpendicular to the nail bed) to the volar base of the metacarpal (Fig. 69-6). Progressively enlarge the hole by using sequential drill bits. Make the drill large enough to accept a tendon-pulling forceps (e.g., Carroll tendon passer; Jarit Surgical Instruments, Hawthorne, New York) and accommodate one half of the FCR tendon. Curette any remaining bone within the channel.
Harvest the radial half of the FCR tendon from 8 cm proximal to the wrist to the base of the index metacarpal. Multiple techniques are available for tendon harvest. Multiple transverse incisions allow safe harvest with minimal scarring.
Pass the free end of the harvested tendon graft through the drill hole from volar to dorsal using the tendon passer (Fig. 69-7). Apply longitudinal traction to the thumb to re-create the trapezial space and position the first ray. The thumb metacarpal base should align with the index metacarpal base. Avoid pulling too hard and overdistracting the trapezial space.
Hold thumb position 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.
Draw the tendon taut and place suture between tendon and dorsal periosteum of metacarpal (Fig. 69-8). 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.
Weave the remaining strip of the harvested FCR in a figure-of-eight fashion between the remaining FCR and abductor pollicis longus (APL) tendons (Fig. 69-9).
Repair the origin of the thenar musculature back to the metacarpal. Close the subcutaneous tissue and skin.