Clinical and magnetic resonance imaging-based outcomes to 5 years after matrix-induced autologous chondrocyte implantation to address articular cartilage defects in the knee

Am J Sports Med. 2011 Apr;39(4):753-63. doi: 10.1177/0363546510390476. Epub 2011 Jan 21.


Background: The availability remains limited of midterm clinical and radiologic results into matrix-induced autologous chondrocyte implantation (MACI). Outcomes are required to validate the efficacy of MACI as a suitable surgical treatment option for articular cartilage defects in the knee.

Hypothesis: A significant improvement in clinical and magnetic resonance imaging-based (MRI-based) outcomes after MACI will exist throughout the postoperative timeline to 5 years after surgery. Furthermore, patient demographics, cartilage defect parameters, and injury/surgery history will be associated with patient and graft outcome, whereas a significant correlation will exist between clinical and MRI-based outcomes at 5 years after surgery.

Study design: Case series; Level of evidence, 4.

Methods: A prospective evaluation was undertaken to assess clinical and MRI-based outcomes to 5 years in 41 patients (53 grafts) after MACI to the knee. After MACI surgery and a 12-week structured rehabilitation program, patients underwent clinical assessments (Knee injury and Osteoarthritis Outcome Score, SF-36, 6-minute walk test, knee range of motion) and MRI assessments at 3, 12, and 24 months, as well as 5 years after surgery. The 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 demonstrated for all Knee injury and Osteoarthritis Outcome Score and SF-36 subscales over the postoperative timeline, as well as the 6-minute walk test and active knee extension. A significant improvement (P < .0001) was observed for the MRI composite score, as well as several individual graft scoring parameters. At 5 years after surgery, 67% of MACI grafts demonstrated complete infill, whereas 89% demonstrated good to excellent filling of the chondral defect. Patient demographics, cartilage defect parameters, and injury/surgery history demonstrated no significant pertinent correlations with clinical or MRI-based outcomes at 5 years, and no significant correlations existed between clinical and MRI-based outcome measures. At 5 years after surgery, 98% of patients were satisfied with the ability of MACI surgery to relieve knee pain; 86%, with improvement in their ability to perform normal daily tasks; and 73%, with their ability to participate in sport 5 years after MACI.

Conclusion: These results suggest that MACI provides a suitable midterm treatment option for articular cartilage defects in the knee. Long-term follow-up is essential to confirm whether the repair tissue has the durability required to maintain long-term patient quality of life.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cartilage, Articular / injuries
  • Cartilage, Articular / pathology
  • Cartilage, Articular / surgery*
  • Child
  • Chondrocytes / transplantation*
  • Female
  • Follow-Up Studies
  • Humans
  • Knee Injuries / pathology
  • Knee Injuries / surgery*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Prospective Studies
  • Transplantation, Autologous
  • Treatment Outcome
  • Young Adult