title: Autologous chondrocyte implantation for treatment of cartilage defects of the knee: what predicts the need for reintervention?
abstract: BACKGROUND
  Autologous chondrocyte implantation (ACI) is a well-established treatment option for isolated cartilage defects of the knee joint, providing satisfying outcome. However, cases of treatment failure with the need for surgical reintervention are reported; typical patient's individual and environmental risk factors have previously not been described.
  
  
  OBJECTIVE
  The need for reintervention after ACI is associated with specific preoperative detectable individual risk factors.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A total of 413 patients following ACI (first, second, and third generation) were filtered for those who required revision surgery during their follow-up time (2-11.8 years). Factors were analyzed that might have significant effects on increased revision rate. Using preoperatively collected data, all patients were grouped according to 12 standard prognostic factors. Apart from odds ratio and Pearson χ(2) test, statistical analysis of risk factors was performed with multivariate binary logistic regression models and Cox regression, the method of choice for survival time data.
  
  
  RESULTS
  After a follow-up of 4.4 ± 0.9 years (limited to 5 years), a total of 88 patients (21.3%) had undergone surgical revision. The time to revision surgery was 1.8 ± 1.1 years. Four prognostic factors associated with a significantly higher risk for reintervention were detected: (1) female gender (Cox survival fit: P = .033), (2) previous surgeries of the affected joint (P = .002), (3) previous bone marrow stimulation (P = .041), and (4) periosteum patch-covered ACI (P = .028). An influence of patient age, body mass index (BMI), defect number, defect size, lesion origin, lesion location, parallel treatment, or smoking on the risk for reintervention could not be observed.
  
  
  CONCLUSIONS
  The study identifies clear facts that significantly increase the risk of revision surgery. These facts can be easily obtained preoperatively and may be taken into consideration when indicating ACI.
authors.affiliation: Department of Orthopedic Surgery and Traumatology, Freiburg University Hospital, Freiburg, Germany. Pia.Jungmann@ucsf.edu
authors.forename: Pia M
authors.initials: PM
authors.lastname: Jungmann
authors.forename: Gian M
authors.initials: GM
authors.lastname: Salzmann
authors.forename: Hagen
authors.initials: H
authors.lastname: Schmal
authors.forename: Jan M
authors.initials: JM
authors.lastname: Pestka
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.forename: Philipp
authors.initials: P
authors.lastname: Niemeyer
mesh_terms: D000328:Adult; D001182:Arthroscopy; D002358:Cartilage, Articular / Q000293:injuries* / Q000601:surgery*; D016009:Chi-Square Distribution; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D015718:Fibrin Tissue Adhesive / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008567:Membranes, Artificial; D010521:Periosteum / Q000601:surgery; D011379:Prognosis; D016016:Proportional Hazards Models; D012086:Reoperation / Q000706:statistics & numerical data*; D012307:Risk Factors; D014014:Tissue Adhesives / Q000627:therapeutic use; D014182:Transplantation, Autologous; D016896:Treatment Outcome
chemical_list: D015718:Fibrin Tissue Adhesive; D008567:Membranes, Artificial; D014014:Tissue Adhesives