Background: Microfracture, the standard of care, is recognized to be an incomplete solution for cartilage damage. BST-CarGel, a chitosan-based medical device, is mixed with autologous whole blood and is applied to a microfractured cartilage lesion in which it physically stabilizes the clot and guides and enhances marrow-derived repair. An international, multicenter, randomized controlled trial was conducted to evaluate BST-CarGel treatment compared with microfracture alone in the repair of cartilage lesions in the knee.
Methods: Eighty patients between the ages of eighteen and fifty-five years with a single, symptomatic focal lesion on the femoral condyles were randomized to BST-CarGel and microfracture treatment (n = 41) or microfracture treatment alone (n = 39). The primary end points of repair tissue quantity and quality at twelve months were assessed by quantitative three-dimensional magnetic resonance imaging measuring the degree of lesion filling and T2 relaxation time with use of standardized one and twelve-month posttreatment scans. The secondary end point at twelve months was clinical benefit determined with the Western Ontario and McMaster Universities Osteoarthritis Index. The tertiary end point was quality of life determined by the Short Form-36. Safety was assessed through the recording of adverse events.
Results: Patient baseline characteristics were similar in the two groups, although baseline lesion areas were slightly larger on quantitative magnetic resonance imaging for the BST-CarGel group compared with the microfracture group. Blinded quantitative magnetic resonance imaging analysis demonstrated that, at twelve months, when compared with microfracture treatment alone, BST-CarGel treatment met both primary end points by achieving statistical superiority for greater lesion filling (p = 0.011) and more hyaline cartilage-like T2 values (p = 0.033). The lesion filling values were 92.8% ± 2.0% for the BST-CarGel treatment group and 85.2% ± 2.1% for the microfracture treatment group, and the mean T2 values were 70.5 ± 4.5 ms for the BST-CarGel treatment group and 85.0 ± 4.9 ms for the microfracture treatment group. Western Ontario and McMaster Universities Osteoarthritis Index subscales for pain, stiffness, and function yielded equivalent improvement for both groups at twelve months, which were significant (p < 0.0001) from baseline. Treatment safety profiles were considered comparable.
Conclusions: At twelve months, BST-CarGel treatment resulted in greater lesion filling and superior repair tissue quality compared with microfracture treatment alone. Clinical benefit was equivalent between groups at twelve months, and safety was similar.
Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
1Department of Surgery, Dalhousie University, 5595 Fenwick Street, Suite 311, Halifax, NS B3H 4M2, Canada. E-mail address: email@example.com
2Department of Orthopaedic Surgery, University of British Columbia, 65 Richmond Street, Suite 102, New Westminster, BC V3L 5P5, Canada. E-mail address: firstname.lastname@example.org
3School of Medicine, CEU San Pablo University, Campus Monteprincipe, 28668 Boadilla del Monte, Madrid, Spain. E-mail address: email@example.com
4University of Calgary Sport Medicine Centre, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada. E-mail address: firstname.lastname@example.org
5Département d’orthopédie, Hôpital de l’Enfant-Jésus, Centre de Recherche du CHU de Québec, 1401 18ème Rue, local B-2416, Québec, QC G1J 1Z4, Canada. E-mail address: email@example.com
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