Thumb Arthritis: Hard Body Anchor and Tape CMC Suspensionplasty

Thumb Arthritis: Hard Body Anchor and Tape CMC Suspensionplasty

This surgical technique for a patient with thumb CMC arthritis addresses the pain by removal of the trapezium bone and maintains function and mobility of the thumb with a sling of graft reinforced with a synthetic SutureTape construct between 2 anchors. A single 4 cm to 5 cm incision is made on the side of the wrist. Care is taken to protect nearby vessels and nerves.

The trapezium bone is removed with a trapeziectomy tool. The rongeur tool may remove this bone in one piece with a rotational maneuver, as seen here. This will alleviate the patient's pain from the constant bone-on-bone contact. The surgeon checks that essential anatomy, such as vessels and nerves, even this tendon behind the trapezium, is not damaged.

The surgeon is now assessing where he will be placing anchors for the best position of the sling. A tendon is harvested as a free graft or autograft. This will serve as the suspension sling between the thumb and the index finger. To harvest a tendon graft like this is a very common procedure all over the body. This tendon in particular is very thick and its function after surgery is not compromised.

As the surgeon isolates the tendon, its thickness, and several slips can be appreciated here. The harvested tendon must be 2 mm in width and about 5 cm to 6 cm long, as it must fit the anchor's forked tip and the drilled anchor socket. The width is measured and is 2 mm. The tendon is stitched at both ends for ease of use and loaded onto the anchor forked tip.

The free tendon will be augmented with a synthetic tape called a SutureTape to provide added strength and resist stretching of the construct. This will also provide a quicker return activity. Suture ends are secured onto the anchor tab. The SutureTape is then loaded onto the anchor tip.

The thumb metacarpal is dissected for clearance, and the first metal wires are inserted to guide the cannulated drill for the anchor's socket. The metal wire is inserted midline. This allows the sling to be right in the middle of the saddle of the thumb metacarpal. The cannulated drill is next, and its depth is controlled by a positive stop. This only allows the drill to be inserted exactly 10 mm into the bone and no more.

This tunnel is ready for anchor insertion shortly. The second metacarpal's anchor socket is planned and drilled with the same steps. Retractors aid the surgeon and visualization. The anchor with the graft and SutureTape construct is now inserted into the thumb metacarpal. Suture is unwrapped from the tab, and the anchor is tested.

The graft and tape are twisted together for ease of tensioning into the index base. The thumb is slightly distracted to align the joint between the thumb and index. The second anchor secures the tendon and SutureTape construct into the index metacarpal. Correct tensioning of the sling is checked for full range of motion of the thumb.

All remaining graft and suture is cut and the capsule is stitched up. The trapezial void will fill with the hematoma or scar ball over the next couple of weeks as the wound heals.