Scapholunate Ligament Reconstruction Using an Acellular Dermal Matrix: A Mechanical Study

Abstract

Numerous surgical techniques have been described for the treatment of chronic scapholunate ligament instability. We hypothesized that scapholunate ligament reconstruction using an acellular dermal matrix was biomechanically comparable to previously described surgical reconstructions. The scaphoid and lunate with the entire scapholunate ligament were harvested from 15 cadaveric specimens. The scapholunate ligament was transected and reconstructed using an acellular dermal matrix (Arthroflex; LifeNet Health, Virginia Beach, VA) and 4 micro suture anchors in 10 specimens. Five specimens were kept with the native scapholunate ligament intact. Five other specimens were reconstructed using a 1.0-mm-thick dermal matrix, and a second cohort of 5 specimens was reconstructed using a 1.5-mm-thick matrix. Tensile testing of all specimens was performed using a servohydraulic material testing system and data acquisition software. The tensile test apparatus applied a distractive load of 10 mm/min (0.17 mm/s) until the specimens reached ultimate failure. Failure force, failure displacement, stiffness, and energy to failure were calculated. All 5 specimens in the intact group failed at the scapholunate ligament midsubstance. The mean ultimate failure force was 172 N, with mean stiffness of 74 N/mm. In the reconstruction group with 1.0-mm dermal matrices, the mode of failure was at the suture-matrix interface in all specimens, whereas the 1.5-mm dermal matrix reconstruction cohort all failed at the bone-suture anchor interface. In the 1.0-mm reconstruction group, the mean ultimate failure force was 77 N, with mean stiffness of 24 N/mm. In the 1.5-mm dermal matrix reconstruction cohort, the mean ultimate failure force was 111 N, with mean stiffness of 30 N/mm. Scapholunate ligament reconstruction using acellular dermal matrix and suture anchors demonstrated similar biomechanical properties to previously described reconstruction techniques. Scapholunate ligament reconstruction using acellular dermal matrix warrants clinical investigation as a potential treatment alternative for chronic scapholunate instability.