Superior survivorship and plate-related results of TomoFix compared to Puddu plate fixation for opening-wedge high tibial osteotomy: A systematic review of the literature

Biomechanical and biocompatibility study of carbon fibre/kevlar high tibial osteotomy elastic composite plate

INTRODUCTION

Currently, the T-shaped titanium Tomofix bone plate is the most commonly used internal fixation bone plate in Open-wedge high tibial osteotomy (HTO). However, the modulus of elasticity of the hard titanium alloy plate does not match the modulus of elasticity of the human cortical bone, resulting in a large "stress shielding effect." At the same time, HTO bone plates have a certain elasticity of demand.

MATERIALS AND METHODS

In this study, the classical mechanical properties of carbon fibre/Kevlar composite plates were tested in bending, tensile and compression with different weaves ((plain weave/twill weave/W-weave/I-weave) and thicknesses. The biomechanical results after internal fixation of titanium and carbon fibre/Kevlar composite HTO bone plates of three different thicknesses (2.0 mm, 2.5 mm, and 3.0 mm) were analyzed and compared using the finite element analysis (FEA) method, and their biocompatibility was investigated by the cell proliferation assay, and the analysis of live/dead staining activity.

RESULTS

The combination of mechanical strength and toughness of the 2.0 mm thick twill weave carbon fibre/Kevlar composite bone plate showed the best performance and a modulus of elasticity of 44.5 GPa.The finite element simulation shows that the 2.0 mm thick twill carbon fibre/Kevlar elastic composite bone graft plate has the best effect in reducing the "stress shielding effect". In addition, the carbon fibre/Kevlar material has good biocompatibility, and it does not react with hemolysis.

CONCLUSION

The 2.0 mm twill weave carbon fibre/Kevlar elastic composite bone plate has sufficient strength and excellent toughness, and its modulus of elasticity is more compatible with human cortical bone, which fully meets the special demand for elasticity of HTO bone plate and at the same time, reduces the "stress shielding effect" with the best effect. Therefore, carbon fibre/Kevlar composites have great potential in the application of HTO bone plates.

Risk Factors and Clinical Outcomes of Osteotomy Plane Violation by D-Hole Screws in Medial Open Wedge High Tibial Osteotomy: A Simulation and Comparative Study

Background and Objectives: Stable fixation is essential for successful healing after medial open wedge high tibial osteotomy (MOWHTO) to minimize the risk of non-union and correction loss. In Asians, potential complications such as D-hole screw osteotomy plane violation (D-hole violation) and inadequate plate fitting arise due to improper plate size. This study aimed to evaluate the risk factors for D-hole violation and compare the conventional anatomic (CA) plate with an individualized anatomic (IA) plate in MOWHTO procedures. Materials and Methods: A simulation study on D-hole violation using the CA plate was conducted, involving preoperative radiographs and CT scans of 64 lower extremities from 47 MOWHTO patients. Additionally, a randomized controlled study compared CA and IA plates in MOWHTO procedures with 34 patients (17 in the CA plate group; 18 in the IA plate group). Patient demographics, patient-reported outcome measures (PROMs), and radiological measures were analyzed. Results: In the simulation study, the rates of D-hole violation ranged from 20.3% to 59.4%, with an increase observed as the plate was distalized from 5 mm to 10 mm away from the joint line. Short stature was identified as an independent risk factor for D-hole violation (p < 0.001), with a cutoff value of 155.3 cm. In the randomized controlled study, no significant difference in PROMs and D-hole violation was observed between the CA plate and IA plate groups. However, the IA plate group showed better plate fitting compared to the CA plate group (p = 0.041). Conclusions: This study identified a high risk of D-hole screw osteotomy plane violations in MOWHTO procedures, particularly when the plate is positioned more distally and in individuals with a stature below 155.3 cm. It also revealed that individualized plates provide better tibial fitting compared to conventional anatomic plates, particularly in Asian populations where tibial morphology tends to be shorter than in Western populations. Therefore, evaluating patient stature and selecting tailored plates are essential to optimize plate positioning and minimize plate-related complications in MOWHTO procedures.

Fixation method can affect posterior tibial slope in opening-wedge high tibial osteotomy: a retrospective study

BACKGROUND

Posterior tibial slope (PTS) alterations following open-wedge high tibial osteotomy (OWHTO) can cause instability and excessive tibial translation in the sagittal plane. These changes can be influenced by the type of fixation. This study aims to compare PTS changes between patients undergoing OWHTO with Puddu plate or TomoFix plate fixation.

METHODS

In this retrospective cohort study, we included 104 knees from 85 patients undergoing OWHTO, with a mean age of 41.98 ± 9.95 years; 51.8% of the participants were male. Seventy-two knees were fixed with Puddu plates, while 32 knees were fixed with TomoFix plates. PTS changes, demographic factors, Cincinnati Knee Rating Score (CKRS), Tegner-Lysholm score (TLS), length of stay (LOS), and complications were evaluated. PTS changes were measured preoperatively, immediately postoperatively, and at the 6-month follow-up.

RESULTS

Demographic factors were similar between the Puddu plate and TomoFix groups. There were no significant differences in preoperative, postoperative, or follow-up PTS measurements between the two groups. PTS changes were not significant in the TomoFix group postoperatively or at follow-up. However, the Puddu plate group showed a significant increase in PTS both postoperatively (P = 0.027) and at follow-up (P = 0.014). CKRS, TLS, LOS, and complications did not significantly differ between the groups.

CONCLUSION

While overall PTS changes did not significantly differ between the Puddu Plate and TomoFix Plate groups, analyzing changes within each group revealed distinct results. TomoFix fixation exhibited nonsignificant PTS changes, while Puddu plate fixation resulted in a significant increase in PTS after surgery and at the 6-month follow-up. Our findings suggest that the choice of fixation may influence PTS changes after OWHTO.

LEVEL OF EVIDENCE

Level III.