Objective To assess the clinical significance of modular femoral component in restoring femoral offset after total hip arthroplasty.Methods Data of 75 patients,who had undergone THA with modular femoral component from June 2009 to June 2012,were retrospectively analyzed.There were 42 males and 33 females,aged from 44 to 83 years (average,64.7±12 years).There were 40 cases of left hip and 35 cases of right hip.The average Harris hip score was 54±6 (range,32 to 65) before operation.The Zimmer M/L Taper hip prosthesis with Kinectiv technology was used in all patients.Preoperative templating was utilized to accurately predict the prosthetic size and the femoral offset.During the surgery,the femoral offset was measured accurately,and the appropriate femoral neck prosthesis was selected in order to restore the femoral offset and reconstruct hip abductor moment arm.The femoral offset and leg length were measured according to X-rays after operation.The Harris hip score was used to assess the clinical results.Results The femoral offset was reconstructed in all patients,ranging from-3.0 to 3.0 mm (average,1.3±0.3 mm).The average leg length discrepancy was improved to 3.0±0.8 mm.All patients were followed up for 6 to 36 months (average,19.7 months).The average hip abduction angle was 40°±10° at 12 weeks after operation.The average Harris hip score was 86±13 (range,65-94) at 12 weeks after operation and 95±15 (range,78 to 98) at final follow-up.There was no hip dislocation and femoral acetabular impingement syndrome.Conclusion Modular femoral component can restore femoral offset without changing the leg length,which can result in good hip abductor strength,range of motion of the hip and stability,as well as less complications.