title: Cell-Seeded Autologous Chondrocyte Implantation: A Simplified Implantation Technique That Maintains High Clinical Outcomes.
abstract: BACKGROUND
  The use of autologous chondrocyte implantation (ACI) remains limited, even though multiple studies have demonstrated success rates exceeding 75%. The procedure is perceived as invasive and technically challenging, presenting barriers to more widespread adoption. Purpose/Hypothesis: The objective of this study was to investigate whether outcomes and the failure rate of a simplified ACI technique (cs-ACI) were comparable with those of the more complicated traditional technique of a chondrocyte suspension injected under a collagen membrane (cACI). We hypothesized that the change in technique would not negatively affect outcomes.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  Thirty-nine patients treated with the cs-ACI technique fulfilled the inclusion requirements. A group of 45 patients treated previously with standard cACI was used as a comparison. The functional outcomes were prospectively collected both preoperatively and postoperatively at the last follow-up. Failure was defined as any graft removal of more than 25% of the original defect size. Magnetic resonance imaging was performed postoperatively, and scans were assessed using a modified MOCART (magnetic resonance observation of cartilage repair tissue) scoring system.
  
  
  RESULTS
  Group demographics were not significantly different, except for the defect size and mean follow-up: 4.09 years in the cACI group and 2.46 years in the cs-ACI group. Significant improvements were seen in all outcome measures except the Tegner score from the preoperative baseline to the latest follow-up for both the cACI group (International Knee Documentation Committee [IKDC] score, from 42.0 to 63.4; Knee injury and Osteoarthritis Outcome Score [KOOS]-Pain subscore, from 58.7 to 77.1; Lysholm score, from 57.2 to 69.7; and Tegner score, from 3.5 to 4.2) and the cs-ACI group (IKDC score, from 45.6 to 68.0; KOOS-Pain subscore, from 66.6 to 84.7; Lysholm score, from 53.7 to 75.4; and Tegner score, from 3.2 to 3.8). No significant difference was found between the groups at the latest follow-up. The failure rate at 2 years was not significantly different, while the total failure rate over the entire study period was significantly lower in the cs-ACI group than the cACI group (5% vs 24%, respectively). The overall MOCART score was not significantly different between the groups.
  
  
  CONCLUSIONS
  The treatment of full-thickness articular cartilage defects with a simplified cell-seeded ACI technique demonstrated no significant differences in the failure rate and patient-reported outcomes when compared with a standard technique utilizing interrupted sutures and the injection of a cell suspension under a collagen membrane.
authors.affiliation: Cartilage Repair Center and Center for Regenerative Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Gomoll
authors.affiliation: Cartilage Repair Center and Center for Regenerative Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.|Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Ambra
authors.affiliation: Cartilage Repair Center and Center for Regenerative Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Phan
authors.affiliation: Cartilage Repair Center and Center for Regenerative Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Marissa
authors.initials: M
authors.lastname: Mastrocola
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts, USA.
authors.forename: Nehal
authors.initials: N
authors.lastname: Shah
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000601:surgery*; D019902:Chondrocytes / Q000637:transplantation*; D015331:Cohort Studies; D003094:Collagen / Q000737:chemistry; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods*; D020370:Osteoarthritis, Knee / Q000601:surgery; D010146:Pain / Q000601:surgery; D014182:Transplantation, Autologous / Q000379:methods; D055815:Young Adult
chemical_list: D003094:Collagen
keywords: ACI; cartilage repair; chondrocyte; collagen membrane