Evaluating functional outcome of patients with limb length discrepancy after total hip replacement: a clinical prospective study

Background: Total hip arthroplasty is a reliable procedure for relief of pain in patients with avascular necrosis of head of femur and osteoarthritis of hip joint. In order to optimize function, hip mechanics should be restored to as near normal as possible. This includes restoration of limb length as well as femoral offset after total hip arthoplasty. There are two types of limb length discrepancies-apparent and true. Apparent Limb length discrepancy is due to pelvic obliquity. True limb length discrepancy is actual discrepancy caused due to under or oversized implants or due to contracture of tissues not allowing bones to achieve their anatomical position. Methods: Surgeries were performed at Dayanand medical hospital. Preoperative templating was performed in all cases. Patients were examined before surgery and six months after surgery. In order to compare the outcomes of patients with different degrees of leg length discrepancy, patients were divided into four groups. The limb length discrepancy was measured both clinically and radiologically. Results: Leg length discrepancies were there in postoperative patients. 3 have shortening of more than 5 mm, 8 have lengthening between 5-10 mm, 7 patients have lengthening more than 10 mm, 28  have  discrepancy within 5mm. Functional outcome of patients was measured by using Harris hip score at a follow up of six months. In our series mean preoperative Harris hip score was 45.59 and mean Harris hip score at follow up was 89.70 (97–84), of which 52.2% graded as excellent and 47.8% as good. Conclusions: In our study we found no correlation between leg length discrepancy and functional outcome following total hip arthroplasty was found.