Four-corner Fusion Method Using a Bioabsorbable Plate for Scapholunate Advanced Collapse and Scaphoid Nonunion Advanced Collapse Wrists: a Case Series Study

Background: Scaphoid excision and four-corner arthrodesis is an acceptable salvage procedure for the treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrists, since first popularized in the 1980s. We investigated the potential application of novel bioabsorbable plates and screws made of un-sintered hydroxyapatite/poly-L-lactide composite for the treatment of metacarpal fractures. We used this material for the fixation of four-corner fusions for SLAC or SNAC wrists commencing from April 2009. The purpose of this study was to clarify the controversy in the literature regarding the use of these plates.

Methods: The surgical procedures and clinical outcomes of four-corner fusions using a bioabsorbable (poly-L-lactic acid and hydroxyapatite) plate were reported. Ten patients (mean age, 59.2 years) with SLAC or SNAC wrists underwent fusions between April 2009 and June 2016. The primary diseases were scapholunate ligament injury, Preiser disease, and scaphoid pseudarthrosis. The mean postoperative follow-up period was 45.9 months (range, 12-86).

Results: In all patients, bone union was achieved without dislocation or pain. The mean wrist flexion and extension arc improved from 78.5 degrees before surgery to 90.5 degrees after surgery. Mean grip strength improved from 51 to 69% after surgery, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score improved from 53.5 to 14.3. No complications such as infection, avascular swelling, or tendon adhesion were observed. This implant requires no removal of internal fixation devices, produces stable outcomes, and is an effective fusion technique.

Conclusions: We summarized the outcomes of four-corner arthrodesis using bioabsorbable plates. Satisfactory clinical results were shown, with no obvious complications. This novel plate also serves as a good alternative for patients who are allergic to metals. Furthermore, bioabsorbable plates are advantageous as they do not require removal.