Trial Comparing BST-CarGel and Microfracture in Repair of Articular Cartilage Lesions in the Knee

A Randomized, Comparative Multicenter Clinical Trial Evaluating BST-CarGel™ and Microfracture in Repair of Focal Articular Cartilage Lesions on the Femoral Condyle

This study will investigate whether the treatment of damaged cartilage in the knee with BST-CarGel will increase the amount and quality of cartilage repair tissue when compared with microfracture alone. Furthermore, the effect of BST-CarGel in decreasing cartilage related pain and improving cartilage-related function in the knee will be assessed.

Cartilage repair currently remains a problematic orthopedic concern with no effective solution. The development of new surgical techniques or therapies is critical in meeting this medical need. This Canadian trial will be a pivotal protocol study, conducted as a randomized, controlled trial. A total of 80 subjects, 40 subjects in each of the two groups (BST-CarGel applied to a microfractured lesion or microfracture alone), will be enrolled in this study. The subjects and investigative medical staff will not be blinded to treatment due to the difference in surgical incision size. However, although the treatment will not be blinded, the primary effectiveness assessment will be blinded. The primary endpoint of this study will be cartilage repair at 12 months proved by demonstrating that BST-CarGel treatment effectively fills cartilage lesions with high quality cartilaginous tissue. The secondary endpoints will be pain, stiffness and function while other tertiary endpoints will include safety, quality-of-life (QOL), as well as macroscopic characterizations of tissue repair. The primary measure of this study will occur at 12 months, when imaging of repair tissue using magnetic resonance (MR) and associated analyses will compare tissue volume, quality and other anatomical variables. Radiographic evaluations will be blinded. Volunteer biopsies at 13 months may be obtained. Pain, stiffness, function and QOL will be assessed prior to treatment, and at 3, 6 and 12 months following treatment using self-administered validated scores (WOMAC and SF-36). In addition, subject safety will be assessed through a record of adverse events.

Cartilage repair, Cartilage, Knee, Knee Pain, Microfracture, arthroscopy, bone marrow stimulation, Chondrogenesis, Scaffold, Chitosan, A02.165.165, A10.165.382.332, G07.574.500.325.377.625.180, A10.165.382.400, Articular Cartilage Repair

BST-CarGel applied to a Microfractured lesion in repair of focal articular cartilage lesions on the femoral condyle

Evaluate the efficacy of BST-CarGel® applied to a microfractured lesion as compared to microfracture alone on the degree of lesion filling of the study knee in subjects with symptomatic pain associated with cartilage damage using MRI scans. The MR images will be acquired using high resolution 3D cartilage imaging sequences, so-called cartilage morphology sequences.

Evaluate the efficacy of BST-CarGel® applied to a microfractured lesion as compared to microfracture alone on the repair tissue quality of the study knee in subjects with symptomatic pain associated with cartilage damage using MRI T2 mapping. T2 maps are created by calculating the T2 relaxation times for repair tissue and cartilage plates for every voxel (picture element of a MRI scan containing the average signal information of a specific spatial location of the imaged body).

Change From Baseline for Knee-related Pain, Stiffness and Function at 12 Months (WOMAC Parts A, B, C)

The three sub-scales: 1) Pain, 2.) stiffness and 3.) function scores ranged from 0-10. Pain had 5 items and stiffness had 2 items, and function had 17 items. The total score for pain ranged from 0 no pain to 50 worst pain. The total score for stiffness ranged from 0 no stiffness to 20 worst stiffness. The total score for function raged from 0 no function to 170 worst function.

Inclusion Criteria: Between 18 and 55 years of age Focal articular cartilage lesion on the medial femoral condyle Grade 3 or 4 acute (traumatic) or chronic (degenerative) lesion Stable knee Exclusion Criteria: Multiple lesions or kissing lesions Clinically relevant compartment malalignment (> 5 degrees) Undergone ligament treatments in the affected knee within 2 years prior to trial Inflammatory arthropathy, such as rheumatoid arthritis, systemic lupus, or active gout Previous surgical cartilage treatments in the affected knee in the last 12 months

Hoemann CD, Hurtig M, Rossomacha E, Sun J, Chevrier A, Shive MS, Buschmann MD. Chitosan-glycerol phosphate/blood implants improve hyaline cartilage repair in ovine microfracture defects. J Bone Joint Surg Am. 2005 Dec;87(12):2671-2686. doi: 10.2106/JBJS.D.02536.

Chevrier A, Hoemann CD, Sun J, Buschmann MD. Chitosan-glycerol phosphate/blood implants increase cell recruitment, transient vascularization and subchondral bone remodeling in drilled cartilage defects. Osteoarthritis Cartilage. 2007 Mar;15(3):316-27. doi: 10.1016/j.joca.2006.08.007. Epub 2006 Sep 26.

Hoemann CD, Sun J, McKee MD, Chevrier A, Rossomacha E, Rivard GE, Hurtig M, Buschmann MD. Chitosan-glycerol phosphate/blood implants elicit hyaline cartilage repair integrated with porous subchondral bone in microdrilled rabbit defects. Osteoarthritis Cartilage. 2007 Jan;15(1):78-89. doi: 10.1016/j.joca.2006.06.015. Epub 2006 Aug 8.

Stanish WD, McCormack R, Forriol F, Mohtadi N, Pelet S, Desnoyers J, Restrepo A, Shive MS. Novel scaffold-based BST-CarGel treatment results in superior cartilage repair compared with microfracture in a randomized controlled trial. J Bone Joint Surg Am. 2013 Sep 18;95(18):1640-50. doi: 10.2106/JBJS.L.01345.