Distal radioulnar joint kinematics before surgery and 12 months following open foveal reinsertion of the triangular fibrocartilage complex: comparison with the contra-lateral non-injured joint

Abstract

Background and purpose — Foveal triangular fibrocar-tilage complex (TFCC) lesion may cause distal radioulnar joint (DRUJ) instability. Dynamic radiostereometry (dRSA) has been validated for objective measurement of DRUJ kine-matics. We evaluated DRUJ kinematics by dRSA before surgery and 12 months following open foveal reinsertion of the TFCC in comparison with contralateral non-injured DRUJs. Patients and methods — In a prospective cohort study, 21 patients (11 men) of mean age 34 years (22–50) with arthroscopically confirmed foveal TFCC lesion were evaluated preoperatively, and at 6 and 12 months after open foveal TFCC reinsertion with QDASH, PRWE, pain on NRS, and bilateral dRSA imaging during a patient active press test motion cycle, including a force-loaded downstroke and a release phase. Results — Preoperatively, the force-loaded part (> 2.3 kg; 95% CI 1.6–3.0) of the press test motion cycle (from 15% to 75%) revealed a more volar position of the ulnar head in the sigmoid notch (DRUJ position ratio) and increased distance in DRUJs with foveal TFCC lesion compared with the patients’ contralateral non-injured DRUJ (p < 0.05). 6 months postoperatively, the DRUJ position was generally normalized and remained normalized at 12 months. However, the DRUJ distance remained higher on the injured side. 12 months post-operatively, patients reported less pain during activities, with improved QDASH and PRWE scores (p < 0.007). Interpretation — DRUJ kinematics during the press test showed increased DRUJ translation to a more volar position of the ulnar head after foveal TFCC lesion compared with the contralateral non-injured DRUJs. Open foveal TFCC reinsertion had a stabilizing effect on DRUJ kinematics towards normalization, and improved patient-reported outcomes 6 and 12 months after surgery.