title: Correlations between BMP-4 gene expression, heterotopic ossification and function after uncemented total hip replacement.
abstract: BACKGROUND
  Heterotopic ossification (HO) is the abnormal, non-neoplastic presence of lamellar bone in soft tissue. Bone morphogenetic proteins (BMP) are among factors that may lead to HO. The purpose of the study was to evaluate correlations between BMP-4 gene expression and HO and the influence of those factors on outcomes of cementless total hip replacement (THR).
  
  
  METHODS
  A series of sixty-four (64) patients were enrolled. The patients were at a mean age of 52.3 years and all of them had undergone unilateral THR. Mean duration of follow-up was 56.74 months. At the last follow-up visit, 1 ml blood samples were collected and BMP-4 gene expression was measured by the RT-PCR technique. Hip radiographs were also obtained and a clinical examination was performed during that visit.
  
  
  RESULTS
  A strong statistical correlation was observed between HO grades according to Brooker's scale and BMP-4 expression levels (rho=0.946, p<0.0001), while there was no correlation between clinical outcomes according to the Harris Hip Score (HHS) and Brooker's grades (rho= -0.188, p=0.3) as well as between Harris hip scores and BMP-4 expression levels (rho=0.1, p=0.6).
  
  
  CONCLUSIONS
  BMP-4 expression strongly correlates with HO as measured by Brooker's scale and may play a role in the aetiology of this condition. The over-expression of BMP-4 may exert a certain influence on ectopic bone formation after total hip arthroplasty.
authors: Department of Orthopaedics and Paediatric Orthopaedics, Medical University in Łodź.
authors: Adam
authors: A
authors: Kwapisz
authors: Piotr
authors: P
authors: Kozłowski
authors: Janusz
authors: J
authors: Szemraj
authors: Marek
authors: M
authors: Synder
authors: Marcin
authors: M
authors: Sibiński
mesh_terms: D000328:Adult; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging* / Q000235:genetics*; D015207:Osteoarthritis, Hip / Q000235:genetics / Q000601:surgery; D011183:Postoperative Complications / Q000517:prevention & control; D011859:Radiography; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D055415:Bone Morphogenetic Protein 4