Proximal Femoral Geometry in Indians and its Clinical Applications

Fractures of the proximal femur involving the neck and trochanters are quite common. Internal fixation of these fractures with implants is mandatory for early mobilization and rehabilitation of the patients. These implants have been designed according to the dimensions of the proximal femur. These are exclusively designed according to the Western dimensions. Most of our Indian Orthopaedic surgeons have currently felt the need for modification of these dimensions to suit the Indian standards. The usage of these over-sized implants adversely affects the functional end result of the surgery. To our knowledge references about the proximal femoral dimensions including neck shaft angle, length and width of the femoral neck in the Indian literature are scarce. Therefore this study was carried out in dry bones to enlighten the Orthopaedic surgeons and Biomechanical engineers about the proximal femoral geometry. An attempt has been made to compare the obtained results with the dimensions of existing implants. 578 unpaired femora collected from the departments of Anatomy, Sri Ramachandra Medical College and Research Institute (SRMC & RI)Chennai, Vinayaka Misssions Kirupananda Variyar Medical College (VMKVMC) Salem and Madras Medical College (MMC) Chennai were used for the present study. The data regarding the dimensions of the implants were collected from the department of Orthopaedics SRMC 8 RI, Chennai. The neck-shaft angle, length and width of the neck of femur were studied using goniometer and vernier calipers respectively as per standard guidelines. The results were recorded and worked out statistically. The average neck shaft angle in the present study was found to be 126.55 degrees. The mean neck length was found to be 3.19 cm and the mean width was 3.1 cm. The present study concludes that the dimensions of currently available Western orthopaedic implants do not match the dimensions of the proximal femora of Indians and stresses the need for modification of the same.