title: Arthroscopic matrix-induced autologous chondrocyte implantation: 2-year outcomes.
abstract: OBJECTIVE
  To determine the safety and efficacy of a new arthroscopic technique for matrix-induced autologous chondrocyte implantation (MACI) for articular cartilage defects in the knee.
  
  
  METHODS
  We undertook a prospective evaluation of the first 20 patients treated with the MACI technique (including 14 defects on the femoral condyle and 6 on the tibial plateau), followed up for 24 months after surgery. A 12-week structured rehabilitation program was undertaken by all patients. Patients underwent clinical assessment (Knee Injury and Osteoarthritis Outcome Score, Short Form 36 Health Survey, visual analog pain scale, 6-minute walk test, knee range of motion) before surgery and at 3, 6, 12, and 24 months after surgery and underwent magnetic resonance imaging (MRI) assessment at 3, 12, and 24 months after surgery. MRI evaluation assessed 8 previously defined pertinent parameters of graft repair, as well as a combined MRI composite score.
  
  
  RESULTS
  A significant improvement (P < .05) was shown throughout the postoperative time line for all Knee Injury and Osteoarthritis Outcome Score subscales, the physical component score of the Short Form 36 Health Survey, the frequency and severity of knee pain, and the 6-minute walk test. An improvement in pertinent morphologic parameters of graft repair was observed to 24 months, whereas a good to excellent graft infill score and MRI composite score were observed at 24 months after surgery in 90% and 70% of patients, respectively.
  
  
  CONCLUSIONS
  We report a comprehensive 24-month follow-up in the first 20 patients who underwent the arthroscopic MACI technique. This technique is a safe and efficacious procedure with improved clinical and radiologic outcomes over the 2-year period.
authors.affiliation: School of Sport Science, Exercise and Health, University of Western Australia, Crawley, Australia. jay.ebert@uwa.edu.au
authors.forename: Jay R
authors.initials: JR
authors.lastname: Ebert
authors.forename: Michael
authors.initials: M
authors.lastname: Fallon
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Ackland
authors.forename: David J
authors.initials: DJ
authors.lastname: Wood
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Janes
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy / Q000534:rehabilitation; D002358:Cartilage, Articular / Q000293:injuries*; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D007718:Knee Injuries / Q000534:rehabilitation / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D020127:Recovery of Function; D054457:Tissue Scaffolds; D016896:Treatment Outcome; D055815:Young Adult