Does Far Cortical Locking Improve Fracture Healing in Distal Femur Fractures: A Randomised, Controlled, Prospective Multicentre Study.

(1) Background: Bone healing is influenced by various mechanical factors, such as stability, interfragmentary motion, strain rate, and direction of loading. Far cortical locking (FCL) is a novel screw design that promotes bone healing through controlled fracture motion. (2) Methods: This study compared the outcome of distal femur fractures treated with FCL or SL (standard locking) screws and an NCB plate in a randomised controlled prospective multicentre trial. The radiographic union scale (RUST) and healing time was used to quantify bone healing on follow-up imaging. (3) Results: The study included 21 patients with distal femur fractures, 7 treated with SL and 14 treated with FCL screws. The mean working length for patients with SL screws was 6.1, whereas for FCL screws, it was 3.9. The mean RUST score at 6 months post fracture was 8.0 for patients with SL plates and 7.3 for patients with FCL plates (p value > 0.05). The mean healing time was 6.5 months for patients with SL plates and 9.9 months for patients with FCL plates (p value < 0.05). (4) Conclusions: Fractures fixed with SL plates had longer working lengths and faster healing times when compared to FCL constructs, suggesting that an adequate working length is important for fracture healing regardless of screw choice.

Fracture reduction has a dominant effect over cerclage wiring in increasing stiffness of intertrochanteric OTA/AO 31-A3.1 (reverse oblique) fractures managed with cephalomedullary osteosynthesis.

OBJECTIVES: To investigate the mechanical properties of cephalomedullary nailing of intertrochanteric OTA/AO 31-A3.1 (reverse oblique) fractures and to test the hypothesis that anatomical reduction and augmentation with cerclage wire produces a more stable construct. METHODS: A standardized fracture model in composite saw bone was created to stimulate an intertrochaneric 31-A3.1 fracture, using a 3D printed cutting guide. Simulated osteosynthesis was performed with 12 femurs divided into anatomically reduced and varus malreduced groups. Each femur was tested with and without cerclage wire augmentation. All femurs were fixed with a 215 mm, 130 degree, 11.5 mm nail. An Instron 8874 biaxial materials testing machine was used to assess the axial stiffness. Cyclic loading consisted of 5000 cycles of sinusoidal combined axial-torsion loading at 3 Hz. Axial load was 100 N to 2000 N and torsion -4.5 Nm to +4.5 Nm. Stiffness was measured before and after cyclic loading. RESULTS: Reduced constructs were stiffer than residual varus constructs. The mean overall fracture stiffness was 508.7 N/mm for reduced constructs and 379.2 N/mm for varus constructs. Removing the cables significantly decreased the fracture stiffness for both constructs (mean difference 60.0 N/mm, 95% CI 7.7-112.3, P = .032). CONCLUSIONS: Anatomical reduction has a dominant effect on facture stiffness. Anatomically reduced fractures are stiffer than varus malreduced fractures. A cerclage wire further improves construct stiffness if anatomical reduction is achieved. Cerclage wiring is less effective if anatomical reduction is not achieved.

Cardiac transplant due to metal toxicity associated with hip arthroplasty.

Concerns regarding metal-on-metal (MoM) bearing couples in total hip arthroplasty are well documented in the literature with cobalt (Co) and chromium (Cr) toxicity causing a range of both local and systemic adverse reactions. We describe the case of a patient undergoing cardiac transplantation as a direct result of Co and Cr toxicity following a MoM hip replacement. Poor implant positioning led to catastrophic wear generating abundant wear particles leading to Co and Cr toxicity, metallosis, bony destruction, elevated metal ion levels, and adverse biological responses. Systemic symptoms continued for 3 years following cardiac transplantation with resolution only after revision hip arthroplasty. There was no realization in the initial cardiac assessment and subsequent transplant workup that the hip replacement was the likely cause of the cardiac failure, and the hip replacement was not recognized as the cause until years after the heart transplant. This case highlights the need for clinicians to be aware of systemic MoM complications as well as the importance of positioning when using these prostheses.