title: Treatment of Pre-Collapse Stages of Osteonecrosis of the Femoral Head: a Systematic Review of Randomized Control Trials.
abstract: BACKGROUND
  Treatment for osteonecrosis of the femoral head (ONFH) remains controversial. Current reviews include low-level evidence studies evaluating the treatment of both pre-collapse and collapse stages of the disease.
  
  
  OBJECTIVE
  The purpose of the current study is to systematically review the literature evaluating core decompression (CD) with bone marrow mesenchymal cells (BMMCs), CD alone, and bisphosphonate treatment in pre-collapse ONFH by focusing just on randomized clinical trials (RCTs) reporting functional and radiologic outcomes. We aim to determine if the literature provides evidence supporting any single approach.
  
  
  METHODS
  Using PubMed and EMBASE databases, we reviewed the clinical evidence of treatments for pre-collapse ONFH following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Twelve RCTs met the inclusion criteria.
  
  
  RESULTS
  Results showed that CD with BMMCs has lower risk of femoral head collapse when compared to the CD alone excluding hips lost to follow-up (relative risk (RR) [95% CI]:0.25 [0.11, 0.60];p= 0.002) and when assumed that hips lost to follow-up experienced collapse (RR [95% CI]: 0.11 [0.03, 0.47];p= 0.003). Neither CD nor bisphosphonate treatments showed lower risk to femoral head collapse when compared to control treatments (p= 0.46 and 0.31, respectively).
  
  
  CONCLUSIONS
  Current literature shows that there is a lower risk of femoral head collapse in patients with ONFH treated with CD combined with BMMCs when compared to CD alone; however, there is no robust evidence to determine the effect on functional outcomes. More RCTs assessing new combination therapies and using standardized outcome measures are required.
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Jordan C
authors.initials: JC
authors.lastname: Villa
authors.affiliation: Weill Cornell Medical College, New York, NY 10065 USA.
authors.forename: Solomon
authors.initials: S
authors.lastname: Husain
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Jelle P
authors.initials: JP
authors.lastname: van der List
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Arianna
authors.initials: A
authors.lastname: Gianakos
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Lane
keywords: femoral head; osteonecrosis; pre-collapse treatment