Midterm Functional Outcome of the Linked Semiconstrained Distal Radioulnar Joint Prosthesis

Background  A painful unstable distal radioulnar joint (DRUJ) can seriously compromise hand and wrist function. The semiconstrained prosthesis was developed to restore DRUJ function. To date, most outcome reports are coauthored by the designer. Questions  Does independent reporting confirm the promising results of the semiconstrained DRUJ prosthesis? Are complication and failure rates acceptable? Patients and Methods  We evaluated patients with the semiconstrained DRUJ implant and a minimum follow-up of 2 years. We monitored patient satisfaction and function with functionality questionnaires and measured wrist range of motion, grip, and key pinch strength. Statistical analysis was done using descriptive statistics, Pearson correlation coefficients, linear and logistic regression. Results  We included 41 patients with 42 implants. Mean follow-up was 46 months (range: 24-102 months). Eighty percent of wrist had undergone previous surgery. We found a mean pronation of 83 degrees (0-90 degrees), supination of 70 degrees (0-90 degrees), flexion of 42 degrees (0-90 degrees), extension of 49 degrees (0-90 degrees), ulnar deviation of 24 degrees (0-60 degrees), and radial deviation of 14 degrees (0-40 degrees). Grip and key pinch strength were 20.1 (1-50 kg) and 6 kg (1-12 kg), respectively. Average patient-rated wrist and hand evaluation score was 42.7 (0-95), disabilities of the arm, shoulder and hand score was 38 (0-88), and visual analog scale score was 3.6 (0-8). We found a 43% complication rate (mostly minor: ulnar or radial tendinopathy, temporary hypoesthesia) with 24% reoperation and 92% prosthesis survival rate. Conclusion  The linked semiconstrained DRUJ prosthesis has its value in the surgical treatment of DRUJ failure. Currently, most implants are used in secondary surgery and multioperated wrists. More research is required to assess the value of the DRUJ prosthesis as a primary procedure. Level of evidence  This is a level IV, therapeutic study.