Biomechanical analysis of ridged dorsal wrist backslabs
Year: 2025
Type: article
Abstract: BackgroundWhile variations in casting technique exist, wrist backslab casts are typically constructed from 8 or 10 layers of plaster material. Moulding a reinforcement ridge in the longitudinal axis of volar slab casts has been shown to increase their tensile strength enormously. This biomechanical study compared the failure force of pragmatically designed dorsal wrist backslab casts in flexion and extension. MethodsRidged and non-ridged 8-layered casts were created using a mould of an investigator’s forearm, wrist and hand (n=24). Six casts in each group were subjected to simulated wrist flexion and 6 to simulated wrist extension. Failure of the cast was defined by the point at which plastic deformation began. Failure load was recorded in each test. Independent two-sample t-test and effect size were used to compare force. Variance in failure load was analysed with Levene’s test.FindingsRidges protruded 8.1 +/- 1.6 mm above cast surface for the combined flexion and extension groups, with no significant difference between groups. Ridged casts had a 1.6 times greater failure load in extension compared to non-ridged casts (p=0.00064; Cohen d=3.42). In flexion, ridged cast failure load was not significantly stronger than in non-ridged (1.15 times, p=0.16; Cohen d=0.98). The variance of failure load was significantly different between the two groups (p=0.0025).InterpretationThe addition of a dorsal longitudinal ridge on a dorsal wrist backslab increases its failure force in wrist extension but not in flexion. The benefit conferred by the ridge in our study varied due to minor differences in ridge height.
Source: Journal of Orthopaedic Reports
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $600
OpenAlex ID: W4408929954