title: Evaluation of magnetic resonance imaging and clinical outcome after tissue-engineered cartilage implantation: prospective 6-year follow-up study.
abstract: BACKGROUND
  Autologous chondrocyte implantation (ACI) is an important procedure when repairing cartilage defects of the knee. We previously reported several basic studies on tissue-engineered cartilage, and conducted a multicenter clinical study in 2009. In this clinical study, we evaluated the patients' clinical scores and MRI findings before and after tissue-engineered cartilage implantation, and compared the data obtained at 1 year and approximately 6 years post-implantation.
  
  
  METHODS
  Fourteen patients who underwent implantation of tissue-engineered cartilage to repair cartilage defects of the knee were evaluated. Tissue-engineered cartilage was produced by culturing autologous chondrocytes three dimensionally in atelocollagen gel. The patients were evaluated clinically using the Lysholm score, and the original knee-function score at pre-implantation and at 1 year and approximately 6 years post-implantation. MRI scans were obtained at the same observation periods. A modified magnetic resonance observation of cartilage repair tissue (MOCART) system was used to quantify clinical efficacy based on the MRI findings.
  
  
  RESULTS
  In approximately 6 years of follow-up, none of the 14 patients reported any subjective symptoms of concern. The mean Lysholm score and the original knee-function score (63.0 ± 10.1, 59.9 ± 5.7) significantly improved at 1 year after implantation (86.4 ± 11.8, 94.1 ± 9.2), and were maintained until 6 years after implantation (89.8 ± 6.2, 89.9 ± 11.2), although some patients showed deterioration of Lysholm and original knee scores between 1 year post-implantation and the final follow-up. The mean MOCART score was 13.2 ± 12.0 pre-implantation, and 62.5 ± 24.7 at 1 year and 70.7 ± 22.7 at approximately 6 years post-implantation. The MOCART scores at 1 year and 6 years were significantly higher than the pre-implantation score, but there was no significant difference between the scores at 1 and 6 years, indicating that the MRI results at 1 year after implantation were maintained for the next 5 years.
  
  
  CONCLUSIONS
  The clinical scores and MRI findings after implantation of tissue-engineered cartilage were improved at 1 year after implantation and were maintained until 6 years after implantation.
authors.affiliation: Department of Orthopaedic Surgery, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
authors.forename: Kobun
authors.initials: K
authors.lastname: Takazawa
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Goki
authors.initials: G
authors.lastname: Kamei
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uchio
authors.forename: Junji
authors.initials: J
authors.lastname: Iwasa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kumahashi
authors.forename: Taku
authors.initials: T
authors.lastname: Tadenuma
authors.forename: Suguru
authors.initials: S
authors.lastname: Kuwata
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yasuda
authors.forename: Harukazu
authors.initials: H
authors.lastname: Tohyama
authors.forename: Akio
authors.initials: A
authors.lastname: Minami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Muneta
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takahashi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D002358:Cartilage, Articular / Q000601:surgery*; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D007718:Knee Injuries / Q000601:surgery; D007719:Knee Joint / Q000601:surgery*; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010008:Osteochondritis Dissecans / Q000601:surgery; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D014182:Transplantation, Autologous; D016896:Treatment Outcome