ObjectiveTo investigate the technique and short-term effectiveness of the umbrella-shaped memory alloy femoral head support device (umbrella-shaped support device for short) for the treatment of avascular necrosis of femoral head (ANFH). MethodsThe umbrella-shaped support device was fabricated with Ni-Ti alloy, and its biomechanics characteristics were tested by three-dimensional finite element analysis with pro/mechanica software. Between October 2009 and December 2012, 10 patients (18 hips) with ANFH were treated. There were 7 males (12 hips) and 3 females (6 hips), aged 21-53 years (mean, 40.6 years). The disease duration was 1-5 years (mean, 3.3 years). According to Ficat staged criteria, 10 hips were rated as stage Ⅱ, 6 hips as stage Ⅲ, and 2 hips as stage IV. Microtrauma methods were used to erase the necrotic tissue of the femoral head, and the umbrella-shaped support device, autogenous iliac bone graft, and artificial bone were implanted to support the collapsed femoral head. ResultsThree-dimensional finite element analysis showed that the largest stress of umbrella-shaped support device was 1 500 MPa and the largest displacement was 1.75 mm. Operation was successfully completed in the other 10 patients (17 hips) except 1 failure hip (total hip arthroplasty was performed after 6 months). The average follow-up period was 19.7 months (range, 15-26 months). At last follow-up, the results were excellent in 5 hips, good in 9 hips, fair in 2 hips, and poor in 1 hip; the excellent and good rate was 82.35%. The Ficat stage had no change when compared with preoperative stages. ConclusionThe advantages of the umbrella-shaped support device for the treatment of ANFH are to thoroughly remove the sequestrum, to rebuild blood circulation of the femoral head, to increase the machinery supporting of subchondral bone in weight-bearing area of femoral head, and to decrease the localized stress, and it has good short-term effectiveness, but long-term effectiveness needs further observation.