EVALUATION OF PROXIMAL FEMUR GEOMETRY ON PLAIN RADIOGRAPHS AMONG DIFFERENT ETHNIC GROUPS

Abstract

Studies on human proximal femur have been done in different areas of the globe. Variations are found due to different levels of activity, race, genetics, clothing, lifestyle and occupation. Accurate description of femoral morphometry is of great interest for biomedical engineers and orthopedic surgeons, but data from different populations is lacking. Such important data happens to be relevant for surgical issues such as for planning surgery and intervention, correction of neck shaft angle, insertion of surgical screws after a fracture and most importantly for prosthesis and implant design. Adequately shaped implants are critical for fixation of femur after fracture or total hip arthroplasty to reduce implant related complications such as change in leg length, dislocation from improper positioning of implants, implant loosening and dislocation fractures. Significant differences have been noted among African Americans, Caucasians, Chinese and other Asian populations. Femoral head diameter (FHD), femoral neck diameter (FND), femoral neck length (FNL), intertrochanteric length (IL), medial offset (MO), femoral vertical offset (FVO), femoral axis length (FAL), hip axis length (HAL) and neck shaft angle (NSA) are morphological parameters of human proximal femur, taken for diagnosis and surgical intervention. Objective of this study were to compare the differences in proximal femur geometry of right and left femur. To compare the differences in proximal femur geometry among male and female. To compare differences among different ethnic groups and to study associations of proximal femur geometry with BMI, lifestyle factors and comorbidities. The study was conducted in PNS Shifa hospital Karachi from September 2020 to March 2021 after Ethical approval from Bahria University Medical and Dental College. After an informed consent, anteroposterior radiographs of both hips of 75 adults aged 20-70 years were included in the study. This study was designed to compare differences of proximal femur parameters between male and female gender, right and left, different age groups and most importantly between 5 ethnic groups of Pakistan and to note any variations. Statistically significant results were observed between gender in all parameters of proximal femur. The mean values of HD in males was 52.95±2.58mm and females was 45.96±3.08mm. mean value for FND in male was 38.03±3.63mm and in female was 31.99±2.65mm and this was statistically significant (p-value = 0.000). FNL in 2 male was 53.10±7.96mm and in female was 45.82±6.41mm. The obtained mean value of femoral intertrochanteric length in male was 68.93±5.29mm. The mean value in females was 68.93±5.29mm. Mean of the values of femoral medial offset in males was 39.67±7.98mm. The mean value in females was 34.53±6.94mm. In males the mean femoral vertical offset value was 61.82±8.39mm and in female the mean value was 49.02±8.18mm. The following means were observed for male and female FNAL was 108.78±7.16mm for male and 94.47±7.04mm for female. The mean hip axis length (HAL) in males was found to be 126.46±8.19mm and in females it was observed to be 106.21±9.28mm. The mean value of NSA of male was 132.23±5.544º and female was 132.085±6.597º. there was insignificant decrease in NSA between male and female. Significant ethnic differences and a decrease of NSA in age group is observed. It can be concluded that understanding and knowledge of proximal femoral morphometry including variations and correlations among them is vital for an orthopedic surgeon before undertaking any surgical procedure or selection of a proper implant for the patient. Knowing morphological parameters of a population is necessary for designing appropriate medical devices and prosthesis that fit accurately to that population and minimize complications such as implant loosening and implant related fractures