2020 journal article

A Biomechanical Comparison of Modified Radioscapholunate Fusion Constructs for Radiocarpal Arthritis

JOURNAL OF HAND SURGERY-AMERICAN VOLUME, 45(10).

By: J. Shapiro*, S. Feinstein*, E. Jewell*, R. Taylor n, P. Weinhold n & R. Draeger*

co-author countries: United States of America 🇺🇸
author keywords: Biomechanical performance; cadaveric model; headless screws; pin plates; plates and screws
MeSH headings : Arthritis; Arthrodesis; Biomechanical Phenomena; Bone Plates; Bone Screws; Cadaver; Humans; Wrist Joint / surgery
Source: Web Of Science
Added: October 26, 2020

Purpose This biomechanical study compared fixation constructs used in radioscapholunate (RSL) arthrodesis. We hypothesized that plates and screws, pin plate, and headless screws would all provide similarly stable fixation constructs. Methods We chose 27 fresh-frozen cadaveric extremities, 14 of which were matched pairs and randomized them into 3 groups to match age, body mass index, and sex. An RSL arthrodesis was simulated with plates and screws, pin plates, or headless compression screws via a standard dorsal approach to the wrist. Specimens were mounted into a custom jig and cycled through an arc of 120° for 5,000 cycles to simulate 6 weeks range of motion (ROM). A 9-mm stroke differential variable reluctance transducer recorded continuous displacement, and gross hardware failure in the form of screw or pin cutout was investigated after the simulation. Results Greater distraction across the RSL articulation was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the plates and screws and pin plates. Greater average displacement was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the pin plates and plates and screws. Gross hardware failure was observed least in plates and screws followed by pin plates. Conclusions Plate-and-screw and pin-plate constructs are biomechanically superior in resisting RSL distraction compared with headless compression screws for RSL arthrodesis over 6 weeks of simulated ROM in the absence of healing. Clinical relevance The results of this study demonstrated negligible arthrodesis site distraction in the plate-and-screws and pin-plate constructs when 6 weeks of ROM was simulated. When translated to a clinical scenario, these findings may allow earlier discontinuation of external immobilization after surgery. This biomechanical study compared fixation constructs used in radioscapholunate (RSL) arthrodesis. We hypothesized that plates and screws, pin plate, and headless screws would all provide similarly stable fixation constructs. We chose 27 fresh-frozen cadaveric extremities, 14 of which were matched pairs and randomized them into 3 groups to match age, body mass index, and sex. An RSL arthrodesis was simulated with plates and screws, pin plates, or headless compression screws via a standard dorsal approach to the wrist. Specimens were mounted into a custom jig and cycled through an arc of 120° for 5,000 cycles to simulate 6 weeks range of motion (ROM). A 9-mm stroke differential variable reluctance transducer recorded continuous displacement, and gross hardware failure in the form of screw or pin cutout was investigated after the simulation. Greater distraction across the RSL articulation was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the plates and screws and pin plates. Greater average displacement was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the pin plates and plates and screws. Gross hardware failure was observed least in plates and screws followed by pin plates. Plate-and-screw and pin-plate constructs are biomechanically superior in resisting RSL distraction compared with headless compression screws for RSL arthrodesis over 6 weeks of simulated ROM in the absence of healing.