title: Long-term durability of autologous chondrocyte implantation: a multicenter, observational study in US patients.
abstract: BACKGROUND
  Autologous chondrocyte implantation for full-thickness lesions of the distal femur has demonstrated good short- to midterm clinical improvement. However, long-term durability (>5 years) of autologous chondrocyte implantation has not been evaluated in US patients to date.
  
  
  OBJECTIVE
  Patients who improve from baseline to early follow-up will sustain improvement at later follow-up.
  
  
  METHODS
  Case series, Level of evidence, 4.
  
  
  METHODS
  Cartilage Repair Registry patients with full-thickness distal femur lesions who were treated with autologous chondrocyte implantation before December 31, 1996 and had modified overall Cincinnati scores at baseline and 1- to 5-year follow-up scores were re-evaluated at 6- to 10-year follow-up. Autologous chondrocyte implantation durability was determined by comparing early (1-5 years) to long-term (6-10 years) outcomes. Adverse events and treatment failures were recorded. Results Seventy-two patients met eligibility criteria (at baseline: mean age, 37 years; mean lesion size, 5.2 cm(2); and overall condition score, 3.4 points [poor]). Eighty-seven percent of patients (47 of 54) who improved at the earlier follow-up period sustained a mean improvement in overall condition score of 3.8 points from baseline to the later follow-up period (P < .001). From baseline to 10-year follow-up (mean follow-up, 9.2 years), 69% improved, 17% failed, and 12.5% reported no change from baseline. Most failures (75% [9 of 12]) occurred at a mean follow-up of 2.5 years. Thirty patients (42%) had 42 operations after autologous chondrocyte implantation; 24 operations (57%) occurred in patients who met the study definition of failure.
  
  
  CONCLUSIONS
  Treatment with autologous chondrocyte implantation for large, symptomatic, full-thickness lesions of the distal femur can result in early improvement that is sustained at longer follow-up (up to 10 years) in the majority of patients.
authors.affiliation: Richmond Bone and Joint Clinic, 15035 Southwest Freeway, Houston, TX 77478, USA. bmoseley@rbjc.com
authors.forename: J Bruce
authors.initials: JB
authors.lastname: Moseley
authors.forename: Allen F
authors.initials: AF
authors.lastname: Anderson
authors.forename: Jon E
authors.initials: JE
authors.lastname: Browne
authors.forename: Bert R
authors.initials: BR
authors.lastname: Mandelbaum
authors.forename: Lyle J
authors.initials: LJ
authors.lastname: Micheli
authors.forename: Freddie
authors.initials: F
authors.lastname: Fu
authors.forename: Christoph
authors.initials: C
authors.lastname: Erggelet
mesh_terms: D000293:Adolescent; D000328:Adult; D002358:Cartilage, Articular / Q000473:pathology / Q000601:surgery; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D005269:Femur / Q000473:pathology / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019370:Observation; D017063:Outcome Assessment, Health Care; D012042:Registries; D013997:Time Factors; D014182:Transplantation, Autologous / Q000009:adverse effects; D014481:United States; D055815:Young Adult