Four-corner arthrodesis with a radiolucent locking dorsal circular plate: technique and outcomes

Scaphoid excision and four-corner arthrodesis (FCA) is an acceptable motion sparing procedure used to treat wrist arthritis. Recently, a locking dorsal circular plate composed of polyether-ether-ketone has been introduced (Xpode®; TriMed Inc.). The purpose of this study is to assess the efficacy of this specific plate design with regard to FCA.

A retrospective chart review of all patients who underwent FCA with an Xpode® between January 1, 2008 and December 31, 2012 was conducted. Patients were contacted and asked to return to clinic for clinical and radiographic follow-up. Patient demographics, range of motion, grip strength, and complications were collected from medical records. Patients completed a patient-rated wrist evaluation (PRWE). A paired t test was used to compare means, and p values <0.05 were considered statistically significant.

Twenty-six procedures (24 patients) were identified. One patient required full wrist fusion following the initial procedure. Of the 25 remaining wrists, arthrodesis was successfully achieved in 20 (80 %). Eleven patients (13 wrists, 52 %) returned to clinic for an average follow-up of 28 months. Mean wrist extension improved from 30 to 47°, and flexion decreased from 33 to 23°. Average grip strength was 77 % of the uninjured side. The mean PRWE scores for pain and function were 19.7 and 17.1, respectively. Five patients underwent additional operations (two hardware removals, two contracture releases, and one distal radial ulnar joint arthroplasty).

FCA with the Xpode® yielded reasonable results for pain and function and demonstrated a fusion rate of 80 %.