Ultrasonic Anchor-Assisted Restoration of the Scapholunate Ligament Complex: A Cadaveric Study.

PURPOSE: Scapholunate interosseous ligament injuries pose a substantial challenge in hand surgery because of the risk of altered carpal biomechanics and progressive carpal collapse. Although numerous repair techniques exist, an optimal fixation method remains elusive. Advances in ultrasonic technology-transitioning from diagnostic to implant applications-offer potential benefits including enhanced pullout strength, ease of insertion, and reduced bony disruption. This study evaluated the efficacy of an ultrasonic fusion anchor in restoring scapholunate (SL) alignment in a cadaveric model.

METHODS

Eight fresh-frozen cadaveric wrists underwent standardized scapholunate interosseous ligament transection followed by repair with a 1.6 mm ultrasonic fusion anchor. Radiographic measurements, including posteroanterior, clenched fist, and lateral views (LV), along with direct spacer assessments, were obtained at four time points: intact, post-transection, postrepair, and after 500 cycles of loading.

RESULTS

Posteroanterior radiographs demonstrated an increase in the SL interval from intact to postsectioned states, and a reduction toward intact values after repair. Clenched fist views showed a significant increase postsectioning and a reduction toward intact values after repair. LV radiographs revealed an increased SL angle after sectioning and a reduction toward more normal values after repair. Spacer measurements demonstrated a marked widening of the SL interval after transection, and a reduction toward intact values after repair. All measurements demonstrated partial maintenance of SL alignment after cyclic loading.

CONCLUSIONS

Ultrasonic fusion anchors partially restore SL alignment toward intact values and partially maintain alignment after cyclic loading in a cadaveric model.

CLINICAL RELEVANCE: The strength, bioabsorbability, radiolucency, and innovative ultrasonic liquefaction mechanism may offer unique advantages over traditional fixation methods and warrants further investigation in hand surgery.