Summary

VCA provides a single-stage option to treat focal cartilage lesions in the knee that demonstrates promising results in decreasing knee pain and improving clinical outcomes in young to middle-aged patients with articular cartilage defects.

Abstract

Purpose

Viable Cartilage Allograft (VCA) is a cartilage tissue matrix that contains cryopreserved viable allogeneic cartilage fibers. This study aimed to assess safety and benefits in treating focal knee cartilage defects with VCA. We hypothesized VCA is a safe single stage procedure in isolated chondral defects with results comparable or better than other single stage procedures.

Methods

Symptomatic International Cartilage Repair Society (ICRS) grade 3/4A lesions of the femoral condyle or patella were implanted with VCA. 20 patients were implanted, mean age 28.1 (16-56), mean BMI 27.9 ± 5.6, mean follow-up 24.1 months (range 12.0–36.0 months). Lesions were either in the femoral condyle (n=7) or patella (n=13). Lesion sizes ranged from 1.5-6.0 cm2 (mean defect size was 4.58 cm2). International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome (KOOS) subscales, Lysholm, Short Form-12 (SF-12), visual analog scale (VAS) and pain frequency levels were prospectively assessed. Radiographic and magnetic resonance imaging (MRI) was performed at regular intervals post-operatively. Statistical analysis of continuous variables was performed with alpha set at 0.05.

Results

Outcome scores at 6 months increased from pre-operative baseline (POB) and continued to increase at 12 months: IKDC (78.2), Lysholm (89.0), KOOS: Pain (95.8), Symptoms (86.3), ADL (87.8), Sports (85.0), and QOL (75.0). MRI imaging at 3-, 6- and 12-month timepoints showed viable preliminary cartilage tissue with no significant bone edema or graft delamination. Second look arthroscopy (n=2) demonstrated complete fill and incorporation (Brittberg Scores 11/12). Functional scores were maintained at 24(M): IKDC (86.2), Lysholm (87.2), KOOS: Pain (91.7), Symptoms (84.9), ADLs (93.8), Sports (84.4), QOL (81.3).

Conclusion

VCA is an off-the-shelf, single-stage, conformable allogeneic graft that treats chondral defects with no additional fixation. Short-term prospective clinical data show VCA can safely treat chondral defects. Young to middle aged active patients with articular cartilage defects demonstrated decreased knee pain and improvements in functional outcome scores.