title: Implantation of tissue-engineered cartilage-like tissue for the treatment for full-thickness cartilage defects of the knee.
abstract: OBJECTIVE
  The purposes of this study were to evaluate early- to midterm clinical results after implantation of tissue-engineered cartilage-like tissue for the treatment for full-thickness cartilage defects of the knee and to identify the factors affecting the final clinical results.
  
  
  METHODS
  Tissue-engineered cartilage-like tissue was prepared by culturing autologous chondrocytes in atelocollagen gel for 3-4 weeks. A total of 73 knees of 72 patients with full-thickness cartilage defects were implanted with this tissue-engineered cartilage-like tissue. The follow-up of these patients for >5 years (range 5-11 years, median 8.0 years) is reported. The patients were evaluated clinically using a rating scale, as well as arthroscopically, biomechanically, and histologically. A modified magnetic resonance observation of cartilage repair tissue (MOCART) system was used to quantify the magnetic resonance imaging (MRI) findings of the lesions. The patient or defect factors influencing the final clinical outcomes were also investigated.
  
  
  RESULTS
  Clinical rating improved significantly after implantation of tissue-engineered cartilage-like tissue. Arthroscopic findings at 2 years after implantation were graded as normal or nearly normal according to the International Cartilage Repair Society (ICRS) scale in 64 of 73 knees (87.7%). Biomechanically, stiffness of the graft almost equalled the surrounding normal cartilage (87.9-102.5%) at 2 years after implantation. Histologically, overall assessment of the repaired tissue by ICRS Visual Assessment Scale II was 70.4 ± 20.8. The average MOCART score was 13.5 ± 11.3 (0-45) preoperatively, 66.6 ± 16.8 (10-90) at 1 year after implantation, 70.4 ± 16.1 (15-90) at 2 years after implantation, and 72.5 ± 17.4 (15-95) at the final follow-up, indicating that MRI results were maintained. Among the factors investigated, only arthroscopic grade of the repaired lesion at 2 years after implantation was significantly correlated with the final clinical scores.
  
  
  CONCLUSIONS
  Implantation of tissue-engineered cartilage-like tissue for the cartilage defects of the knee was effective in short- to midterm post-operatively. This procedure can be proposed as one option for repairing full-thickness cartilage defect of the knee.
  
  
  METHODS
  IV.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan, nadachi@hiroshima-u.ac.jp.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakamae
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
mesh_terms: D000293:Adolescent; D000328:Adult; D001672:Biocompatible Materials; D002358:Cartilage, Articular / Q000601:surgery*; D002648:Child; D019902:Chondrocytes / Q000637:transplantation*; D003094:Collagen; D005260:Female; D005500:Follow-Up Studies; D005782:Gels; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D023822:Tissue Engineering; D014182:Transplantation, Autologous; D014945:Wound Healing; D014947:Wounds and Injuries / Q000601:surgery; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D005782:Gels; C059821:atelocollagen; D003094:Collagen