Assessment of Wrist Function After Simulated Total Wrist Arthrodesis: A Comparison of 6 Wrist Positions

Background: There is poor consensus in the literature regarding associated functional limitation and the preferred wrist position for total wrist arthrodesis. The purpose of the current investigation was twofold: (1) to assess the functional limitations of wrist arthrodesis and (2) to determine the optimal position for wrist arthrodesis using a simulated wrist fusion model. Methods: Twenty healthy volunteers underwent simulated wrist arthrodesis in 6 different positions using custom-molded wrist splints: 15° extension with 0° radio-ulnar deviation, 15° extension with 10° ulnar deviation, 15° extension with 10° radial deviation, 0° extension with 0° radio-ulnar deviation, 0° extension with 10° ulnar deviation, and 0° extension with 10° radial deviation. Each volunteer was independently assessed for wrist function using the Jebsen-Taylor hand function test, grip strength, and satisfaction in the simulated wrist fusion positions. Comparisons between all simulated fusion wrists and the baseline unsplinted wrist as well as among the 6 simulated fusion positions were performed. Results: Turning over a card (5.1 vs 4.3 seconds), picking up small objects (7.1 vs 5.8 seconds), and simulated feeding (8.3 vs 7.1 seconds) as well as total Jebsen-Taylor test duration (41.8 vs 37.9 seconds) was significantly longer in simulated fusion wrists. Both grip strength (55.9 vs 80.7 kg) and satisfaction scores (6.4 vs 9.6) were lower in simulated fusion wrists. Wrists in 0° extension also demonstrated significantly shorter durations in stacking checkers than wrists in 15° extension. Conclusion: Our findings suggest that wrist arthrodesis may only compromise select wrist functions. Among the tested wrist fusion positions, wrists fused in neutral may demonstrate better function than wrist fused in slight extension. However, grip strength and satisfaction seem to be unaffected by wrist fusion position.