SUMMIT Prospective, Randomized, Controlled Trial: Response Rates To Matrix-induced Autologous Chondrocyte Implant (MACI) Versus Microfracture (MFX) By Lesion Characteristics

Objectives:To compare the response rates of patients treated with the MACI implant with those treated with MFX for the repair of symptomatic articular cartilage defects of the knee, based on lesion characteristics, in the phase 3 SUMMIT (Superiority of Matrix-induced autologous chondrocyte implant versus Microfracture for Treatment of symptomatic articular cartilage defects) trial (sponsored by Sanofi/Genzyme Biosurgery).Methods::Patients with ≥1 symptomatic focal articular cartilage defect of the femoral condyles (MFC/LFC) and/or trochlea and baseline Knee Injury and Osteoarthritis Outcome Score (KOOS) pain score ≤55 participated in this prospective, randomized, controlled trial (NCT00719576). The co-primary endpoint was improvement in KOOS pain and function (sports/recreational activities) at 2-year follow up. A patient was considered a responder if they had at least a 10-point improvement over baseline in KOOS pain and function scores. The Cochran-Mantel-Haenszel χ2 (α=0.05) was used to analyze differe...