Prior Surgery Negatively Affects Cell Culture Identity in Patients Undergoing Autologous Chondrocyte Implantation

Abstract

Background: Recently, a cell identity assay has been introduced to evaluate the identity of cultured chondrocytes before autologous chondrocyte implantation (ACI), which was shown to be associated with graft survival after ACI. Purpose: To identify the influence of several patient- and lesion-specific factors on cell identity and viability assays. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 187 patients with second-generation ACI were included in this study. Patient and lesion characteristics, cell viability, cell identity, and biopsy specimen weight were recorded for each patient. A binomial logistic regression model was utilized to determine patient-specific predictive factors for cell product quality. Results: The implanted ACI cell products showed a cell viability of 93% ± 2.4% (mean ± SD; range, 84-98) with an identity score of 5.8 ± 2.1 (range, –0.08 to 9.46). Patients with multiple previous surgical procedures on the index knee had significantly lower cell identity scores when compared with patients without previous surgery (odds ratio = 0.31; 95% CI, 0.16-0.59; P < .001). Patients without surgical history had significantly higher cell identity scores than patients with 1 and ≥2 previous surgical procedures on the index knee (6.32 vs 5.32 vs 5.05; P = .006 and P < .001, respectively). Cell viability was not predicted by any preoperative variable (P > .05). Cell identity and viability were not associated with each other or with biopsy specimen weight (P > .05). Conclusion: Cartilage biopsy specimens from patients with ≥1 previous surgical procedures resulted in implants with lower cell identity scores when compared with patients without previous operations. None of the other patient- or lesion-specific factors were correlated, specifically biopsy specimen weight.