Context: Matrix-induced autologous chondrocyte implantation (MACI) has become an established technique for the repair of chondral defects in the knee. MACI has traditionally required an open arthrotomy, but now lends itself to an arthroscopic technique, which may decrease the associated comorbidity of arthrotomy, potentially allowing for faster rehabilitation.

Objective: To compare postoperative outcomes between arthroscopic and open arthrotomy techniques of MACI and present a case for faster recovery and accelerated rehabilitation after surgery.

Design: Retrospective cohort study.

Setting: Private functional rehabilitation facility.

Patients: 78 patients (41 arthroscopic, 37 open) treated with MACI for full-thickness cartilage defects to the femoral condyles.

Intervention: According to surgeon preference, patients recruited over the same time period underwent MACI performed arthroscopically or via a conventional open arthrotomy. Both surgical groups were subjected to an identical rehabilitation protocol.

Main outcome measures: Patient-reported (Knee Injury and Osteoarthritis Outcome Score, Short Form Health Survey, and visual analogue scale) and functional (6-minwalk test, 3-repetition straight-leg-raise test [3R-SLR]) outcomes were compared presurgery and at 3, 6, and 12 mo postsurgery. Active knee range of motion (ROM) was additionally assessed 4 and 8 wk postsurgery. MRI evaluation was assessed using magnetic-resonance observation of cartilage-repair tissue (MOCART) scores at 3 and 12 mo. The length of hospital stay was evaluated, while postsurgery complications were documented.

Results: Significant improvements (P < .05) for both groups were observed over the 12-mo period for patient-reported and functional outcomes; however, the arthroscopic cohort performed significantly better (P < .05) in active knee-flexion and -extension ROM and the 3R-SLR. No differences were observed in MOCART scores between the 2 groups at 12 mo. Patients who received arthroscopic implantation required a significantly reduced (P < .001) hospital stay and experienced fewer postoperative complications.

Conclusions: Arthroscopic MACI in combination with “best practice” rehabilitation has shown encouraging early results, with good clinical outcomes to 12 mo, reduced length of patient hospitalization, and reduced risk of postsurgery complications. This may have important implications for postoperative rehabilitation and a faster return to full function.