title: Matrix-induced autologous chondrocyte implantation (MACI) in the knee: clinical outcomes and challenges.
abstract: OBJECTIVE
  Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated effectiveness in treating isolated cartilage defects of the knee but medium- and long-term evidence and information on the management of postoperative complications or partially successful cases are sparse. This study hypothesised that MACI is effective for up to 5 years and that patients with posttreatment problems may go on to obtain clinical benefit from other interventions.
  
  
  METHODS
  A follow-on, prospective case series of patients recruited into a previous controlled, randomised, prospective study or newly enroled. Patients were followed up 6, 12, 24 and 60 months after surgery. Outcome measures were Tegner (activity levels) and Lysholm (pain, stability, gait, clinical symptoms) scores. Zone-specific subgroups were analysed 6, 12 and 24 months postoperatively.
  
  
  RESULTS
  Sixty-five patients were treated with MACI. Median Tegner score improved from II to IV at 12 months; an improvement maintained to 60 months. Mean Lysholm score improved from 28.5 to 76.6 points (±19.8) at 24 months, settling back to 75.5 points after 5 years (p > 0.0001). No significant differences were identified in the zone-specific analysis. Posttreatment issues (N = 12/18.5 %) were resolved with microfracture, debridement, OATS or bone grafting.
  
  
  CONCLUSIONS
  MACI is safe and effective in the majority of patients. Patients in whom treatment is only partially successful can go on to obtain clinical benefit from other cartilage repair options. This study adds to the clinical evidence on the MACI procedure, offers insight into likely treatment outcomes, and highlights MACI's usefulness as part of an armamentarium of surgical approaches to the treatment of isolated knee defects.
  
  
  METHODS
  Prospective case control study with no control group, Level III.
authors.affiliation: ATOS Clinic, Center for Knee and Hip Replacement and Regenerative Joint Surgery, Bismarckstrasse 9-15, 69115, Heidelberg, Germany. basad@atos.de.
authors.forename: Erhan
authors.initials: E
authors.lastname: Basad
authors.affiliation: Department for Trauma and Orthopedic Surgery, Asklepios Klinik Langen, Röntgenstrasse 20, 63225, Langen, Germany. fabian.r.wissing@googlemail.com.
authors.forename: Fabian R
authors.initials: FR
authors.lastname: Wissing
authors.affiliation: Sportklinik Stuttgart GmbH, Taubenheimstr. 8, 70372, Stuttgart, Germany. p.fehrenbach@hotmail.de.
authors.forename: Patrick
authors.initials: P
authors.lastname: Fehrenbach
authors.affiliation: Department for Orthopaedic Surgery, Giessen University Hospital, Klinikstrasse 33, 35392, Giessen, Germany. markus.rickert@ortho.med.uni-giessen.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Rickert
authors.affiliation: Laboratory for Experimental Orthopaedics, University of Giessen, Paul-Meimberg-Str.3, 35392, Giessen, Germany. juergen.steinmeyer@ortho.med.uni-giessen.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Steinmeyer
authors.affiliation: Department for Orthopaedic Surgery, Giessen University Hospital, Klinikstrasse 33, 35392, Giessen, Germany. bernd.ishaque@ortho.med.uni-giessen.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Ishaque
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002358:Cartilage, Articular / Q000601:surgery*; D016022:Case-Control Studies; D019902:Chondrocytes / Q000637:transplantation*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D014182:Transplantation, Autologous; D016896:Treatment Outcome
keywords: Autologous transplantation; Cartilage; Chondrocytes; Knee; Matrix-induced autologous chondrocyte implantation