Single versus double knot tension band wiring: Biomechanical analysis of compression forces in chevron olecranon osteotomies

Purpose Olecranon fractures and osteotomies worldwide are commonly stabilized using tension band wiring (TBW), traditionally tightened with two knots to achieve optimal compression. However, soft tissue irritation and technical issues have led to the adoption of a simplified single-knot technique. This study aimed to compare compression forces at the medial, lateral, and ventral osteotomy surface between single- (SKO) and double-knot osteosynthesis (DKO) using ultra-thin custom pressure sensors. Methods Standardized V-shaped olecranon osteotomies were performed on composite ulnas and fixed with TBW using either SKO or DKO, each performed 10 times. Three pre-calibrated pressure sensors were placed medially (PM), laterally (PL), and ventrally (PV) on each specimen. A 1.25 mm cerclage wire was tightened using a 0.45 Nm torque limiter. Compression forces were compared between SKO and DKO using t-tests, and intra-group differences assessed compression symmetry. Results No significant differences in PM, PL, or PV were found between SKO and DKO ( p = .62, .89, .20). In both groups, ventral pressure was significantly lower than medial and lateral ( p < .001), and lateral pressure exceeded medial in both SKO ( p = .003) and DKO ( p = .004). Conclusion Single-knot TBW provides comparable compression to the traditional double-knot technique, challenging the standard approach. Given its simplicity and similar biomechanical performance, SKO may offer a viable alternative, warranting further clinical evaluation regarding outcomes and complication rates.