title: Arthroscopic second-generation autologous chondrocyte implantation compared with microfracture for chondral lesions of the knee: prospective nonrandomized study at 5 years.
abstract: BACKGROUND
  Various approaches have been proposed to treat articular cartilage lesions, which are plagued by inherent limited healing potential.
  
  
  OBJECTIVE
  To compare the clinical outcome of patients treated with second-generation autologous chondrocyte implantation implants with those treated with the microfracture repair technique at 5-year follow-up.
  
  
  METHODS
  Cohort study; Level of evidence, 2.
  
  
  METHODS
  Eighty active patients (mean age, 29.8 years) and grade III to IV cartilage lesions of the femoral condyles or trochlea were treated with arthroscopic second-generation autologous chondrocyte implantation Hyalograft C or microfracture (40 patients per group). Patients achieved a minimum 5-year follow-up and were prospectively evaluated.
  
  
  RESULTS
  Both groups showed statistically significant improvement of all clinical scores from preoperative interval to 5-year follow-up. There was a significant improvement for the International Knee Documentation Committee subjective score from pre-operative to 5-year follow-up (Wilcoxon test, P < .001). In the microfracture group, the International Knee Documentation Committee objective score increased from 2.5% normal and nearly normal knees before the operation to 75% normal and nearly normal knees at 5-year follow-up, and the subjective score increased from 41.1 +/- 12.3 preoperatively to 70.2 +/- 14.7 at 5-year follow-up. In the group treated with Hyalograft C, the International Knee Documentation Committee objective score increased from 15% normal and nearly normal knees before the operation to 90% normal and nearly normal knees at 5-year follow-up, and its subjective score increased from 40.5 +/- 15.2 preoperatively to 80.2 +/- 19.1 at 5-year follow-up (Wilcoxon test, P < .001). When comparing the groups, better improvement of the International Knee Documentation Committee objective (P < .001) and subjective (P = .003) scores was observed in the Hyalograft C group at 5-year follow-up. The return to sports at 2 years was similar in both groups and remained stable after 5 years in the Hyalograft C group; it worsened in the microfracture group.
  
  
  CONCLUSIONS
  Both methods have shown satisfactory clinical outcome at medium-term follow-up. Better clinical results and sport activity resumption were noted in the group treated with second-generation autologous chondrocyte transplantation.
authors.affiliation: Department of Orthopaedic and Sports Trauma, Rizzoli Orthopaedic Institute, Bologna, Italy. e.kon@biomec.ior.it
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Kon
authors.forename: Alberto
authors.initials: A
authors.lastname: Gobbi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.forename: Marco
authors.initials: M
authors.lastname: Delcogliano
authors.forename: Stefano
authors.initials: S
authors.lastname: Zaffagnini
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000328:Adult; D054544:Arthroplasty, Subchondral; D001182:Arthroscopy / Q000379:methods; D002357:Cartilage Diseases / Q000473:pathology / Q000601:surgery; D002358:Cartilage, Articular / Q000503:physiopathology / Q000601:surgery*; D019902:Chondrocytes / Q000637:transplantation*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000534:rehabilitation / Q000601:surgery*; D008297:Male; D011446:Prospective Studies; D014182:Transplantation, Autologous