gms | German Medical Science

Objectives/Interrogation: To compare the in-vitro efficacy of a knotless suture anchor internal brace technique with the percutaneous pin fixation for wrist stabilization in the setting of scapholunate interosseous ligament injury (SLIL) injury.

Methods: 10 cadaveric forearm pairs were randomly assigned to two groups based upon repair techniques, either internal brace reconstruction or percutaneous pinning (Figure 1 [Fig. 1]). The SLIL was transected utilizing a dorsal approach. A modified Henry approach was utilized to isolate the flexor tendons, which were secured with #5 Ethibond suture. Kirschner wires were placed in the lunate and scaphoid for use as joysticks to aid in reduction, which was held with two transcaphoid, translunate k-wires and one transcaphoid, transcapitate k-wire. In the internal brace group, an Arthrex Swivelock anchor with labral tape was first placed dorsally in the proximal pole of the scaphoid and then secured under tension to the dorsal aspect of the lunate using a second Swivelock anchor. The "V"-shaped construct was completed by bringing the labral tape back to the distal pole of the scaphoid and securing it under tension with a third Swivelock anchor dorsally. For the k-wire repair group, two k-wires were placed percutaneously spanning the scaphoid and lunate and a third was placed spanning the scaphoid and capitate. Retroreflective markers were attached to the distal radius, scaphoid, and lunate to track the 3D motions of each bone. The flexor tendons were loaded to 20 lb at 1 Hz for 300 cycles to simulate physiologic gripping. The change in scapholunate gap (mm) and scapholunate angle (degrees) were calculated after completion of cyclic loading. Paired t-tests were used for statistical comparisons with a p-value <0.05 considered to be statistically significant. All values reported as mean ± standard error.

Results and Conclusions: There was no difference in the increase of the scapholunate gap (0.51 ± 0.14 vs. 0.26 ± 0.18, p>0.05) or angle (0.97 ± 0.23 vs. 1.12 ± 0.33, p>0.05) between repair techniques. The use of an internal brace technique is biomechanically comparable to k-wire fixation in a cadaveric model.