Leg length and offset following hip resurfacing and hip replacement

Area of Science:

• Orthopedic surgery
• Radiographic analysis
• Biomechanical engineering

Background:

• Hip replacement surgery aims to restore function and reduce pain.
• Hybrid hip replacement (CPS/EPF) and cemented hip resurfacing (Cormet) are common procedures.
• Accurate restoration of hip biomechanics is crucial for optimal outcomes.

Purpose of the Study:

• To compare the accuracy of femoral offset and leg length restoration between hybrid hip replacement and cemented hip resurfacing.
• To evaluate radiographic parameters including acetabular offset and cup height.
• To assess the impact of each surgical technique on proximal femoral anatomy.

Main Methods:

• Retrospective radiographic analysis of 28 patients undergoing hybrid hip replacement and 28 undergoing cemented hip resurfacing.
• Measurement of femoral offset, acetabular offset, cup height, and leg length on pre- and post-operative anteroposterior radiographs.
• Statistical comparison using independent sample t-tests to determine significant differences between groups.

Main Results:

• Cemented hip resurfacing demonstrated significantly more accurate restoration of femoral offset (p<0.05) and less post-operative leg length change (p<0.001) compared to hybrid hip replacement.
• No statistically significant difference was found in the restoration of the center of rotation between the two groups.
• Proximal femoral anatomy was better preserved with hip resurfacing through precise bone resection based on templating.

Conclusions:

• Cemented hip resurfacing offers superior accuracy in restoring femoral offset and maintaining leg length compared to hybrid hip replacement.
• Hip resurfacing may lead to better preservation of native proximal femoral anatomy.
• Further research could explore long-term functional outcomes and complication rates.