The evaluation of a de novo biplanar distal humerus plate: A biomechanical study

Objectives: The aim of this study was to compare the stability of a novel biplanar distal humerus plate with the single-and double -columns J-plating techniques. Materials and methods: Eighteen sawbones humera were divided into three groups. In Groups 1, 2 and 3, biplanar plate, single lateral J-plate and double J-plate, were used, respectively. Transverse osteotomies at the upper portion of the olecranon fossa were made. Blocks of 10-mm was removed from each sample. Axial, torsional, and extensional stiffness of each group were measured. Results: The mean axial stiffness values in Groups 1, 2, and 3 were 64.80 +/- 6.75, 33.70 +/- 5.71, and 171.48 +/- 9.53 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.032), whereas Group 3 showed a statistically significant difference compared to Groups 1 and 2 (p=0.025 and p=0.014, respectively). The mean torsional stiffness values of Groups 1, 2, and 3 were 0.23 +/- 0.01, 0.14 +/- 0.008, and 0.30 +/- 0.007 N/ degree, respectively. Groups 1 and 3 demonstrated a statistically significant difference compared to Group 2 (p=0.042 and p=0.028, respectively). No statistically significant difference was detected between Groups 1 and 3 (p=0.27). The mean extensional bending stiffness values of Groups 1, 2 and 3 were 2.64 +/- 0.31, 1.17 +/- 0.13, and 3.2 +/- 0.1 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.041). There was no statistically significant difference between Groups 1 and 3 (p=0.083). Conclusion: Biplanar plate allows applying enough numbers of long sagittal screws and offers more biomechanical stability than lateral column J-plate and in some aspects strong as dual J-plating in torsional and bending tests