TOTAL WRIST ARTHROPLASTY: THE CANADIAN EXPERIENCE AND SUCCESS RATE WITH FOURTH-GENERATION IMPLANTS

Fourth generation total wrist arthroplasty (TWA) represents a novel option for patients with all types of wrist arthritis. Largely because of variable results following early generation TWAs, the indications for 4th generation TWAs are thought to be limited and outcomes are not commonly reported. We report a retrospective case series of 39 TWAs by two surgeons from two Canadian institutions over the last 12 years using only 4th generation implants. Patient-reported wrist pain was recorded preoperatively and years postoperatively. Range of motion and grip strength were measured and DASH scores were recorded. The average patient age at surgery was 55 years, 17 (43 %) were female, and 12 (30%) were work injuries on compensation. Seven patients (18%) had a diagnosis of rheumatoid or psoriatic arthritis, 18 (49%) had painful SNAC or SLAC arthritis, 2 (5%) had Kienbock and 4 (10%) patients had previous distal radius fractures. 30% had previous wrist surgeries. There were no serious complications reported. Wrist pain was measured at 9.1/10 preoperatively and decreased to 2.7/10 postoperatively. Range of motion did not improve significantly postoperatively and was on average a total flexion-extension arc of 50 degrees. Grip strength improved from 46 to 70% compared to the unaffected side (p-value=0.04). DASH scores varied greatly preoperatively (30 to 64) and improved postoperatively (range 9–89). Nine patients (21%) required a subsequent OR following TWA but only one patient required a revision of the distal component for loosening at 5 years post op. Two patients underwent a total wrist fusion at 2 and 10 years after TWA for ongoing chronic pain and neither had loosening of their TWA components. Of note, in the remaining 6 patients the second procedure was not related to an issue of the radiocarpal implant itself but rather issues with the DRUJ, impingement, or tendon adhesions. We report the safety and significant improvement of patients undergoing TWA. With this information, TWA could be incorporated into the surgical strategy for patients with wrist issues including complications from trauma.