Suture Button Compared With K-Wire Fixation for Maintenance of Posttrapeziectomy Space Height in a Cadaver Model of Lateral Pinch

Abstract

Hematoma distraction arthroplasty has regained popularity as a treatment for thumb carpometacarpal arthritis with reports of satisfactory results. Our goal was to investigate the use of a suture button device to maintain the posttrapeziectomy space height of the thumb metacarpal. Our hypothesis is that a suture button that suspends the thumb metacarpal from the second metacarpal, when applied to the hematoma distraction arthroplasty technique, would provide subsidence resistance comparable to traditional K-wire fixation. Ten fresh frozen matched pairs of human cadaveric arms were used. After open trapeziectomy, suspension of the thumb metacarpal was performed with either a 1.4-mm (0.045-inch) K-wire advanced through the base of the thumb metacarpal into the second metacarpal shaft or a suture button device that suspended the thumb metacarpal from the second metacarpal shaft. Cyclic pinch was simulated by using a lateral pinch model previously described and validated. Lateral pinch is simulated by loading the extensor pollicis longus, adductor pollicis, abductor pollicis brevis, and flexor pollicis longus in a 1:5:6:10 ratio. Dynamic pinch is achieved with cyclic unloading of the abductor pollicis brevis, adductor pollicis, and flexor pollicis longus tendons. Measurements were made of the height of excised trapeziums, the distance from the metacarpal base to the scaphoid after trapeziectomy (trapeziectomy space height) at time zero, both loaded and unloaded, and at sequential loading cycles of 1,000, 2,000, 3,000, 4,000, 5,000, and 10,000 cycles. Student t-test evaluation showed no significant differences between the groups in initial trapeziectomy space height (p = .10), postfixation trapeziectomy space height (p = .10), or loss of trapeziectomy space height between precycling and after 10,000 cycles (p = .80). Suture button fixation maintains similar posttrapeziectomy space height and prevents subsidence of the thumb metacarpal when compared with K-wire fixation in this model. This technique may allow for earlier range of motion after the hematoma distraction arthroplasty.