LATERAL OPENING WEDGE DISTAL FEMORAL V-OSTEOTOMY: BIOMECHANICS COMPARISON BETWEEN ANGLES OF 60∘ AND 90∘ IN SHEEP

Abstract

Objective: To evaluate whether 60[Formula: see text] and 90[Formula: see text] V-shaped osteotomies in sheep femurs have statistically significant differences when submitted to compressive strength tests. Material and Methods: A total of 30 left femurs of recently slaughtered sheep were removed, the proximal segment was discarded, and the bones were randomly divided into two groups of 15 specimens each. The bones underwent distal osteotomy at the supracondylar region at a 90[Formula: see text] angle between cuts, in group 1, and at a 60[Formula: see text] angle in group 2. The osteotomy was V-shaped and the distal apex started in the lateral face of the femur; medial cortical bone remained intact. Compressive tests were conducted, and four points of the deformation curve were collected for the calculation of the deformation rate using an interpolation scheme. Deformation patterns were evaluated according to two groups: intercondylar fracture and medial cortical fracture. Results: Group 1 had a mean resistance to failure to compressive load of 232[Formula: see text]kgf (SD 59.551; 150-400), whereas in group 2, mean resistance to failure to compressive load was 157.13[Formula: see text]kgf (SD 67.4; 70-346); this difference was statistically significant ([Formula: see text], Kruskal–Wallis). Conclusions: Osteotomy at a 90[Formula: see text] angle had a greater resistance to compression and resulted in less weakening of the distal area of the femur after osteotomy. There were no differences in the pattern of fracture generated by compression according to osteotomy angle.