Local administration of enriched mononuclear cells, platelets and zoledronic acid for preventing collapse of the femoral head in the early stage of osteonecrosis: study protocol for a prospective randomized parallel-controlled clinical trial

Abstract

Background: Although there are many treatments for osteonecrosis of the femoral head, conservative treatment is often ineffective. Once collapse of the femoral head occurs, the damage is irreversible. Our previous animal studies have shown that local administration of zoledronic acid prevents collapse of the osteonecrotic femoral head. Additionally, bone marrow mononuclear cell therapy has a good short-term clinical effect on osteonecrosis of the femoral head. Currently, it is unclear whether a combination of bone marrow mononuclear cells and platelet-rich plasma may have efficacy in preventing early-stage collapse of the osteonecrotic femoral head. Methods/Design: A prospective, randomized, parallel-controlled, single-center clinical trial will be completed at the Chinese PLA General Hospital, China. One hundred patients with Ficat I-II osteonecrosis of the femoral head will be recruited and equally randomized into treatment and control groups. The treatment group will be given injection of enriched autologous mononuclear cells and zoledronic acid into the necrotic area following core decompression by drilling. In the control group, core decompression by drilling will be done, but no treatment will be given. Patients will be followed up at 3, 6, 12 and 18 months. Dynamic perfusion MR imaging, three-dimensional CT reconstruction, and anteroposterior and lateral X-ray observations of the hip joint will be performed to observe blood supply, bone formation and femoral appearance in the necrotic area. Harris score of the hip joint and a numeric rating scale score will be used to evaluate hip function and pain. These indicators will be used as primary outcome measures. Scores from the 36-Item Short-Form Health Survey and activity of daily living scale will be used as secondary outcome measures. Discussion: The outcomes of this trial will provide quantitative data and related information for evaluating the efficacy of local administration of enriched bone marrow mononuclear cells, platelets and zoledronic acid for the clinical prevention of collapse of the early-stage osteonecrotic femoral head. Trial registration: ClinicalTrial.gov identifier: NCT02721940. Written approval for this protocol was obtained from the ethics committee of the Chinese PLA General Hospital in China (approval No. S2015-082-01).