title: Influence of cell quality on clinical outcome after autologous chondrocyte implantation.
abstract: BACKGROUND
  Several factors influence clinical outcome after autologous chondrocyte implantation (ACI) for the treatment of cartilage defects of the knee joint.
  
  
  OBJECTIVE
  The aim of the present study was to investigate the influence of cell quality on clinical outcome after ACI. The hypothesis of the authors was that cell quality at the time of transplantation influences clinical outcome after ACI for cartilage defects.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A total of 80 patients were included in the present study. Knee function was assessed before surgery as well as 6, 12, and 24 months after ACI using standard instruments (International Knee Documentation Committee [IKDC], Lysholm, and Tegner scores). Cell quality was evaluated by determination of antigen expression of CD44 expression, aggrecan, collagen type II, and cell viability. A linear regression analysis including preoperative knee function, defect size, defect location, defect origin, body mass index, patient age, and other parameters was performed to evaluate the influence of these parameters on postoperative knee function.
  
  
  RESULTS
  Preoperative IKDC score increased from 49.6 ± 13.8 points to 75.5 ± 14.6 points at 24 months (P < .05). Postoperative IKDC score at 6, 12, and 24 months was significantly influenced by collagen type II expression, CD44 expression, and cell viability (all P < .05). No correlation between aggrecan and outcome was found. Quantitative influence of individual factors differed between different time points.
  
  
  CONCLUSIONS
  Cell quality seems to be one of many factors that influences clinical outcome after ACI in patients with cartilage defects of the knee joint. It constitutes one aspect among various others affecting clinical outcome.
authors.affiliation: Freiburg University Hospital, Department of Orthopedic Surgery and Traumatology, Hugstetter Str. 55, 791016 Freiburg, Germany. philipp.niemeyer@uniklinik-freiburg.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Niemeyer
authors.forename: Jan M
authors.initials: JM
authors.lastname: Pestka
authors.forename: Gian M
authors.initials: GM
authors.lastname: Salzmann
authors.forename: Norbert P
authors.initials: NP
authors.lastname: Südkamp
authors.forename: Hagen
authors.initials: H
authors.lastname: Schmal
mesh_terms: D000293:Adolescent; D000328:Adult; D053674:Aggrecans / Q000096:biosynthesis; D002358:Cartilage, Articular / Q000293:injuries* / Q000601:surgery*; D002470:Cell Survival / Q000502:physiology; D019902:Chondrocytes / Q000637:transplantation*; D024043:Collagen Type II / Q000096:biosynthesis; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D007717:Knee / Q000503:physiopathology / Q000601:surgery; D008297:Male; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C508319:ACAN protein, human; D053674:Aggrecans; C497483:CD44 protein, human; D024043:Collagen Type II; D018960:Hyaluronan Receptors