Abstract
OBJECTIVES: Osteochondral allograft transplantation (OCA) is a well-established procedure for the management of osteochondral lesions of the knee. OCA after failed prior cartilage restoration procedures has demonstrated similar improvements in patient-reported outcomes (PROs). Outcomes following OCA after failed autologous chondrocyte implantation (ACI) have been minimally reported in the current literature. The present study aims to compare the clinical outcomes, reoperation rates, and failure rates of OCA following failed ACI with those of a matched cohort of patients undergoing primary OCA. METHODS: A retrospective matched cohort analysis was conducted on 22 patients who underwent OCA following failed ACI between January 2001 and January 2021, with a minimum 2-year clinical follow-up. Patients were included regardless of concomitant procedures. These patients were matched by age, sex, body mass index, defect location, and defect size to a control group of patients who underwent primary OCA without prior ACI with a similar 2-year clinical follow-up. PROs, defect characteristics, reoperations, and failure rates were analyzed individually and compared between the 2 groups. RESULTS: Twenty-two patients (100% follow-up) were included in the study group with an average follow-up of 5.72 ± 4.2 years (range: 2.0-14.5). The average age was 31.2 ± 6.4 years. Sixteen patients were female (73%) and 6 were male (27%). Patients did not differ in the number of previous surgeries, preoperative baseline PROs, or types of concomitant procedures between the study group and the matched cohort. Both cohorts demonstrated statistically significant postoperative improvements for all PROs including Lysholm, International Knee Documentation Committee, and Knee Injury and Osteoarthritis Outcome Score subscales (p < 0.05). There was no statistical difference between both groups when comparing improvements in PROs, number of reoperations, and failure rates (p > 0.05). Ten patients (45%) in the study group required a reoperation. Four patients (18%) failed OCA following an ACI due to significant graft delamination and disease progression at an average 2.4 ± 2.1 years. Two patients required further revision OCA and 2 underwent significant chondral debridement. All 4 patients were clinically asymptomatic at a final follow-up of 5.9 years. CONCLUSIONS: OCA is an excellent treatment option for patients after prior failed ACI. OCA following ACI demonstrates favorable clinical outcomes, comparable reoperation rates, and an acceptable failure rate, similar to OCA performed without prior OCA.