ObjectiveTo compare the early clinical and radiographic outcomes of hemiarthroplasty by a minimal invasive Supercap approach and by a conventional approach for elderly displaced femoral neck fractures. MethodsBetween January and June 2015, 70 geriatric patients with displaced femoral neck fracture underwent cementless bipolar hemiarthroplasty by minimally invasive Supercap approach (group A, n=35) or by posterolateral approach (group B, n=35). One patient was excluded from the study in group B because of too wide femur cavity. There was no significant difference in gender, age, body mass index, fracture cause, time from fracture to operation, fracture side, fracture classification, and preoperative visual analogue scale (VAS), and hemoglobin-level between the 2 groups (P > 0.05). The operation time, intraoperative blood loss, incision length, and complications were recorded. The early clinical evaluations included timed up and go test (TUG), hemoglobin-level, VAS score, and satisfaction. The anteroposterior and lateral X-ray films were taken to measure the stem alignment, difference in leg length, and difference in femoral offset. ResultsAll the patients were followed up 6-11 months (mean, 7.32 months). No patients died during follow-up. There was no significant difference in operation time and intraoperative blood loss between the 2 groups (P > 0.05). The incision length of group A was significantly smaller than that of group B (P < 0.05). One patient had delayed union of incision in group A (2.86%); 2 patients had deep vein thrombosis in group B (5.88%); and there was no significant difference in the complication rate (χ2=0.764, P=0.512). The postoperative hemoglobin level showed no significant difference between the 2 groups (P > 0.05). Group A had lower VAS score and higher subjective satisfaction than group B, showing significant difference at 1, 5, and 14 days after operation (P < 0.05). The TUG of group A was significantly shorter than that of group B at 5, 14, and 30 days (P < 0.05). There was no significant difference in femoral offset or leg length on the X-ray films (t=1.273, P=0.851; t=0.409, P=0.327). The good rate of stem alignment was 82.86% (29/35) in group A, and was 85.30% (29/34) in group B, showing no significant difference (χ2=0.584, P=0.497). ConclusionBoth minimal invasive Supercap approach and conventional posterolateral approach are effective and safe for elderly displaced femoral neck fractures in hemiarthroplasty. Supercap approach has the advantages of less trauma, pain relief, and improvement of mobility and rapid rehabilitation.