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Updated: Jun 17, 2026
Matrix-assisted Autologous Chondrocyte Transplantation for Remodeling and Repair of Chondral Defects in a Rabbit Model
Published on: May 21, 2013
Effect of Lower Limb Alignment and Corrective Osteotomy on Clinical Outcomes After Matrix-Associated Autologous
Akira Maeyama1, Kazuhiko Saeki2, Tetsuro Ishimatsu1
1Department of Orthopaedic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.
Background:
The effectiveness of matrix-associated autologous chondrocyte implantation (MACI) in patients with lower limb malalignment remains debatable.
Hypothesis:
Performing MACI in patients with lower limb alignment abnormalities would result in worse postoperative outcomes than in those without alignment abnormalities.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Patients who underwent MACI using autologous cultured cartilage for traumatic chondral defects and osteochondritis dissecans across 3 institutions between February 2014 and August 2022 were reviewed. Osteotomy was recommended for patients with mechanical alignment (MA) <40% and performed on consenting patients. Evaluation included demographic and clinical variables, Lysholm Knee Score (LKS), Knee injury and Osteoarthritis Outcome Score (KOOS), International Cartilage Regeneration & Joint Preservation Society (ICRS) grade from second-look arthroscopy, and postoperative complications.
Results:
Of 96 cases, 39 showed normal alignment and did not require osteotomy, 44 showed varus alignment and underwent corrective osteotomy, and 13 showed varus alignment but declined osteotomy. All groups showed significant improvement in the LKS and KOOS at 2 years (all P < .05). At 1 year, the normal alignment group showed superior LKS (P = .01) and KOOS Activities of Daily Living (ADL) subscale (P = .04) compared with the varus group without osteotomy. The varus group with osteotomy had significantly better LKS (P = .02) and KOOS ADL (P = .04) than the varus group without osteotomy. ICRS grade-based assessments of medial femoral condylar graft sites showed no significant difference between the normal alignment group and varus group with osteotomy (mean, 10.2 vs 10.0; P = .70). However, significantly worse graft-site repair was noted in patients with MA ≥60% (P = .004), although clinical outcomes were not significantly different. Eight complications were reported in the normal alignment group, with 4 each in the varus groups with and without osteotomy.
Conclusion:
In patients with varus alignment, MACI outcomes were improved when osteotomy was performed to shift alignment toward valgus. The corrected varus group demonstrated cartilage repair status and clinical outcomes comparable with those of the normal alignment group.
