Relative instability ratios of bone wall defects in trochanteric hip fractures: A finite element analysis

Anteromedial Cortical Support in Reduction of Trochanteric Hip Fractures: From Definition to Application

➤ The concept of anteromedial cortical support (AMCS) serves as valuable guidance for the intraoperative reduction of trochanteric hip fractures.➤ Positive medial cortical support (MCS) and positive or neutral anterior cortical support (ACS) are desirable. Some evidence has suggested that positive MCS is potentially superior to neutral MCS.➤ Experimental studies underscore the vital importance of the anteromedial wall and reveal why positive MCS potentially outperforms neutral MCS.➤ Incorporating the AMCS concept, the Chang reduction quality criteria (CRQC) are a reliable alternative approach to evaluate the reduction quality of trochanteric hip fractures.

[Research progress on weak state of lateral wall in intertrochanteric fractures]

Objective

To review the research progress of the weak state of the lateral wall in intertrochanteric fracture, in order to provide clinical references.

Methods

The relevant research literature on the lateral wall of intertrochanteric fracture at home and abroad in recent years was summarized and analyzed in terms of morphology, fracture line in coronal plane, and bone density.

Results

Assessment of weak state of the lateral wall is particularly important in the treatment of intertrochanteric fractures. Lateral wall thickness is the main way to assess the weak state of the lateral wall, but there are still problems. Many scholars at home and abroad have studied various aspects such as width, height, and length of the anterior cortex, but there is a lack of a comprehensive assessment method. Coronal fractures affect lateral wall morphology and are difficult to detect on X-ray films, requiring vigilance on the part of the clinician. Further research is needed to clarify the correlation between bone density and the weak state of the lateral wall. The femur lesser trochanter fractures interacts with the latertal wall, and the lesser trochanter fracture exacerbates the weak state. The soft tissue around the lateral wall also affects the weak state, so attention must be paid to protecting the soft tissues during operation.

Conclusion

There are more methods for assessing the weak state of the lateral wall, but none of them has formed a unified standard. Most of the current studies assess the weak state from a single perspective and lack a comprehensive assessment of all aspects affecting the lateral wall. Fewer studies have been conducted to assess the residual lateral wall function after a partial fracture of the lateral wall, and further research is needed.

Finite element analysis of the effect of residual lateral wall volume on postoperative stability in intertrochanteric fractures

BACKGROUND

Lateral wall fractures represent crucial risk factors for postoperative internal fixation failure in intertrochanteric femoral fractures. However, no consensus exists on the type of lateral wall fracture requiring interventional management. This study aimed to investigate the effect of residual lateral wall volume on the postoperative stability of intertrochanteric femur fractures with associated lateral wall fractures, providing valuable reference for the clinical management of the lateral wall.

METHODS

Eleven bone defect models of intertrochanteric femur fractures with varying residual lateral wall volumes were constructed using finite element analysis. These models were fixed with proximal femoral nail antirotation (PFNA). Simulations of von Mises stress and displacement distribution of the PFNA and femur during normal walking were conducted. Statistical analysis was performed to assess the correlation between volume and the maximum von Mises stresses and displacements of the PFNA and femur.

RESULTS

In all 11 models, the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and femur occurred at the same locations. As residual lateral wall volume increased, the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and maximum femoral displacement gradually decreased. However, the overall trend of the maximum femoral von Mises stress gradually decreased. At 70% retention of the residual lateral wall volume, there was a more pronounced change in the value of the maximum stress change of the helical blade and the intramedullary nail. Statistical analysis, including the Shapiro-Wilk test and Pearson correlation analysis, demonstrated a significant negative correlation between volume and the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and femur. Linear regression analysis further confirmed this significant negative correlation.

CONCLUSION

Finite element analysis of the residual lateral wall revealed a significant correlation between volume and the postoperative stability of intertrochanteric femur fractures. A volume of 70% may serve as the threshold for stabilizing the residual lateral wall. Volume emerges as a novel index for evaluating the strength of the residual lateral walls.