A Study on the Proximal Femoral Geometry for Standardizing the Femoral Component Design to Suit Indian Needs in Total Hip Replacement

Abstract

Background and aims: The percentage of elderly people above 65 years of age & incidence of Osteoarthritis in India is expected to be very high by 2040 AD. The final weapon in the management armamentarium of osteoarthritis is Total Hip Replacement. The femoral component design plays a major role in the success of the surgery. The anatomy of the upper end of femur varies with different populations. The study is aimed to provide guidelines for future design of the femoral stem for Indian population. Materials and Methods: 200 dry human bones were studied. The parameters including: Femoral head off set, femoral head diameter, femoral neck diameter, canal width, endosteal and extra cortical width, ante version angle and neck shaft angle were studied using UTHSCSA Image tool software. The results were analyzed using statistical package SPSS 17.0 version. Results: The average femoral head offset, neck shaft angle and ante version angle was 40.75 mm, 131.48 degrees and 10.69 degrees respectively. The head diameter and neck diameter was 41.77 mm and 28.66 mm respectively. The canal width was 34.87 mm, 49.27 mm and 30.09 mm respectively at the level, 20 mm above the level and 20 mm below the level of lesser trochanter, endosteal width at the level of isthmus was 15.9 mm and extra cortical width at the level of isthmus was 14.03 mm Conclusion: The guideline values obtained for the parameters, particularly the femoral head offset, ante version angle and neck shaft angle are strongly recommended for designing femoral stems.