title: The role of "cell therapy" in osteonecrosis of the femoral head. A systematic review of the literature and meta-analysis of 7 studies.
abstract: OBJECTIVE
  The value of core decrompression for treatment of osteonecrosis of the femoral head (ONFH) is unclear. We investigated by a literature review whether implantation of autologous bone marrow aspirate, containing high concentrations of pluripotent mesenchymal stem cells, into the core decompression track would improve the clinical and radiological results compared with the classical method of core decompression alone. The primary outcomes of interest were structural failure (collapse) of the femoral head and conversion to total hip replacement (THR).
  
  
  METHODS
  All randomized and non-randomized control trials comparing simple core decompression with autologous bone marrow cell implantation into the femoral head for the treatment of ONFH were considered eligible for inclusion. The methodological quality of the studies included was assessed independently by 2 reviewers using the Cochrane Collaboration tool for assessing risk of bias in randomized studies. Of 496 relevant citations identified, 7 studies formed the basis of this review.
  
  
  RESULTS
  The pooled estimate of effect size for structural failure of the femoral head favored the cell therapy group, as, in this treatment group, the odds of progression of the femoral head to the collapse stage were reduced by a factor of 5 compared to the CD group (odds ratio (OR) = 0.2, 95% CI: 0.08-0.6; p = 0.02). The respective summarized estimate of effect size yielded halved odds for conversion to THR in the cell therapy group compared to CD group (OR = 0.6, 95% CI: 0.3-1.02; p = 0.06).
  
  
  CONCLUSIONS
  Our findings suggest that implantation of autologous mesenchymal stem cells (MSCs) into the core decompression track, particularly when employed at early (pre-collapse) stages of ONFH, would improve the survivorship of femoral heads and reduce the need for hip arthroplasty.
authors.affiliation: a 1 Department of Trauma and Orthopaedics, G. Hatzikostas General Hospital , Ioannina, Greece.
authors.forename: Costas
authors.initials: C
authors.lastname: Papakostidis
authors.affiliation: b 2 Academic Department of Trauma and Orthopaedic Surgery, University of Leeds , Leeds.|d 4 NIHR Leeds Biomedical Research Unit, Chapel Allerton Hospital , Leeds, UK.
authors.forename: Theodoros H
authors.initials: TH
authors.lastname: Tosounidis
authors.affiliation: c 3 Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds , Leeds.
authors.forename: Elena
authors.initials: E
authors.lastname: Jones
authors.affiliation: b 2 Academic Department of Trauma and Orthopaedic Surgery, University of Leeds , Leeds.|d 4 NIHR Leeds Biomedical Research Unit, Chapel Allerton Hospital , Leeds, UK.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Giannoudis
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D064987:Cell- and Tissue-Based Therapy / Q000379:methods; D018849:Controlled Clinical Trials as Topic; D005260:Female; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D011379:Prognosis; D011859:Radiography; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012380:Role; D012720:Severity of Illness Index; D014182:Transplantation, Autologous; D016896:Treatment Outcome