RECONSTRUCTION OF THE SCAPHOLUNATE LIGAMENT IN A CADAVER MODEL USING A BONE-LIGAMENT-BONE AUTOGRAFT FROM THE FOOT

This study is an investigation of a new procedure in which the scaphol unate interosseous ligament (SLIL) is reconstructed using a bone-ligam ent-bone autograft from the fool. After investigation, the dorsal medi al portion of the navicular-first cuneiform ligament (NFCL) was chosen for testing as a potential donor since it is similar in length and th ickness to the SLIL and it is easily harvested with minimal potential donor site morbidity. Eight SLILs and NFCLs were harvested from fresh- frozen cadavers. Biomechanical extensometry testing was performed usin g an Instron 1000 machine. A 5-mm-wide central portion of the NFCL was tested since this width was compatible with the technical aspects of reconstructing the SLIL. Both ligaments were tested for elastic proper ties, including stiffness, load to failure, and deformation to failure . Mean length of the NFCL was 7.6 mm (range, 5.5-8.5 mm). Stiffness of the NFCL was 10.6 x 10(5) Nm (range, 8.0-13.0 Nm) compared with 11.4 x 10(5) Nm for the SLIL (range 10.0-19.5 Nm). Peak load to failure for the NFCL was 1,980 N (range, 1,530-2,940 N) compared with 2,940 N for the SLIL (range, 1,780-4,050 N). Total elongation to failure for the NFCL was 2.50 mm (range, 1.7-3.2 mm) compared with 3.2 mm for the SLIL (range, 2.1-5.2 mm). Thus, the biomechanical characteristics of the N FCL were Found to be very similar to those of the SLIL. Having establi shed the biomechanical similarities of the 2 ligaments, we are current ly using the NFCL to reconstruct the sectioned SLIL in a fresh-frozen cadaver model. Early results suggest that this procedure is feasible f or restoration of normal kinematics of the wrist. Copyright (C) 1998 b y the American Society for Surgery of the Hand.