Introduction: The hip joint functions on the bio­engineering principle of moment of force with a fulcrum, lever arm, power arm. Hip joint with the hemi­spherical femoral head articulating in the acetabular cup with abductor muscles acting at one end, the body weight on the other, and the joint itself being the fulcrum can be compared to a ‘First order lever’. To describe the force acting on the hip joint, the body weight can be depicted as a load applied to a lever arm extending from the body’s centre of gravity to the centre of the femoral head. Methodology: During our study period 56 patients met inclusion criteria, and all patients underwent total hip replacement either cemented or uncemented through modified lateral approach. Data was collected from previous operative records, regular follow­up x­ray films and follow­up records. Results: In our study, out of 56 patients, 46 patients (82.2%) had negative modified Trendelenburg test, whereas 10 patients (17.8%) had positive modified Trendelenburg test. Most of the positive modified Trendelenburg test patients were in secondary osteoarthritis group, 7 out of 10. Conclusion: The most common indication for Total Hip Arthroplasty in our study is displaced fracture neck of femur in elderly active patients.

Keywords: Total Hip Replacement; Trendelenburg Test; Total Hip Arthroplasty.