Repair of acute ulnar collateral ligament injuries of the thumb metacarpophalangeal joint: a retrospective comparison of pull-out sutures and bone anchor techniques.

BACKGROUND

The use of intraosseous suture anchors in the treatment of ruptures of the ulnar collateral ligament of the thumb metacarpophalangeal joint has previously been described. However, no direct comparisons exist of ulnar collateral ligament repair with bone anchor versus repair with a pull-out button and immobilization.

METHODS

Two cohorts of patients with complete rupture of the ulnar collateral ligament of the thumb metacarpophalangeal joint were compared. Thirty patients in each cohort underwent repair of the ulnar collateral ligament with either an intraosseous suture anchor followed by early mobilization or a pull-out suture tied over a button with cast immobilization. Average follow-up was 29 months.

RESULTS

At follow-up, range of motion at the metacarpophalangeal and interphalangeal joints for the anchor group averaged 97 percent of that of the contralateral side compared with 86 percent and 87 percent, respectively, for the button group. For the anchor group, pinch strength averaged 101 percent that of the contralateral side compared with 95 percent for the button group. No significant difference was noted between the groups for grip strength. Average tourniquet time for the anchor group was 28 minutes compared with 43 minutes for the button group. Soft-tissue complications were present in 27 percent of patients (eight of 30) in the pull-out button group compared with 7 percent (two of 30) in the anchor group. Cost analysis demonstrates an approximately $140-per-patient savings when using the suture anchor.

CONCLUSIONS

Both repair methods are safe and effective for treating thumb ulnar collateral ligament injuries. Suture anchors allow for an accelerated rehabilitation protocol, which may account for the improved range of motion and pinch strength at follow-up.