2015 ISAKOS Biennial Congress Paper #65
BST-CarGel Treatment Results in Sustained Cartilage Repair Superiority Compared to Microfracture at 5 Years
Matthew Shive, PhD, Toronto, ON CANADA
William David Stanish, MD, FRCS, FACS, AOA, Halifax, NS CANADA
Robert G. McCormack, MD, New Westminster, BC CANADA
Nick Mohtadi, MD, MSc, FRCSC, Dip. Sport Med; Clinical Professor, Calgary, AB CANADA
Stephane Pelet, MD, Quebec, QC CANADA
Jacques Desnoyers, MD, FRCS(c), Ville Lemoyne, AC CANADA
Francisco Forriol, MD, PhD, Madrid SPAIN
Kendra Vehik, PhD, Tampa, FL UNITED STATES
Stéphane Méthot, BEng, PhD, Laval, QC CANADA
Alberto Restrepo, MD, Montreal, QC CANADA
Piramal Healthcare, Laval, Quebec, CANADA
FDA Status Not Applicable
Summary: An international cartilage repair RCT demonstrated sustained structural superiority of the repair tissue by quantitative 3D MRI for BST-CarGel treatment over microfracture alone at 5 years post-treatment. Both treatment groups showed significant and equivalent improvement over baseline at 5 years for all 3 WOMAC subscales (p < 0.0001). Equivalent safety for both treatments was demonstrated.
Abstract:
Introduction
BST-CarGel (Piramal Life Sciences, Bio-Orthopaedics Division, Laval, Canada) is a chitosan-based device which is applied over a microfractured cartilage lesion where it enhances early marrow-derived repair processes. A multicenter RCT was conducted to evaluate the efficacy and safety of BST-CarGel for cartilage repair in the knee compared to microfracture alone at 1 year and was continued under an extension protocol to evaluate 5 year post-treatment outcomes.
MATERIALS & METHODS
The international (Canada, Spain, South Korea) RCT enrolled 80 patients, aged 18 to 55, with BMIs<30 and symptomatic grade III or IV focal lesions on the femoral condyles. Patients were randomized (1:1) at the time of surgery to BST-CarGel or microfracture alone, and followed standardized 12 week rehabilitation. Repair tissue quantity and quality was evaluated as the primary endpoint up to 5 years by standardized MRI and three-dimensional quantification of lesion %Fill and T2 relaxation times. Secondary endpoints were clinical benefit determined using WOMAC questionnaires and safety at 1 and 5 years. General estimating equations were used for longitudinal statistical analysis of repeated measures.
Results
Blinded MRI analysis demonstrated that BST-CarGel-treated patients showed a significantly greater treatment effect for lesion filling over the 5 year follow-up (p=0.017) compared to microfracture. A significantly greater treatment effect for BST-CarGel was also observed for repair tissue T2 relaxation times (p=0.026), indicating a more ordered and cartilage-like collagen structure compared to the microfracture group. The BST-CarGel and microfracture treatment groups both showed significant improvement from pre-treatment baseline at 5 years for all 3 WOMAC subscales of pain, stiffness and function (p < 0.0001). There was no difference between the treatment groups over the 1 to 5 year period for the WOMAC subscales. Safety by recording of adverse events was comparable for both groups over the 5 year study.
Conclusion
At 5 years post-treatment, patients treated with BST-CarGel demonstrated sustained and significantly superior durability of repair over microfracture for repair tissue quantity and quantity. Additionally, the clinical benefit at 5 years for BST-CarGel was highly significant over the baseline levels of pain, stiffness and function, illustrating that BST-CarGel is a safe and effective treatment for symptomatic full-thickness cartilage lesions.