Patient Factors Associated with Osteochondral Allograft Success in Knees with or without Co-morbidities

OBJECTIVES: To determine preoperative variables that may influence outcomes after osteochondral allograft transplantation for treatment of large cartilage defects in the knee. METHODS: A retrospective review of 75 patients who underwent osteochondral allograft transplantation for large (>1 cm) grade IV cartilage defects in knees was performed. Patient variables evaluated included: smoking, workers compensation, BMI, pre-injury activity level (high level athlete, recreational athlete, active non-athlete, minimal activity, sedentary), number and type of co-morbidities in the operated knee (meniscal, ligament, and/or other cartilage pathology), lesion location (medial femoral condyle, lateral femoral condyle or multiple lesions), number of grafts placed (1, 2 or >2) and patients who underwent revision surgery related to OCA transplantation. Preoperative and postoperative VAS pain scores were used as the primary outcome measure. Success was defined as a VAS pain score of 0 or improvement in score (decrease) of 2 or more at final follow-up. The mean follow-up time was 19.5 months (3-53 months). Statistically significant (p<0.05) effects on successful outcomes were evaluated using Fisher's exact tests and odds ratios. RESULTS: The study population was 41 males and 34 females with an average age of 34.2 years (14-61). 53 patients (71%) had successful outcomes. 59 patients (79%) had co-morbidities with the average being 2 comorbidities (1-4) per patient. 68% of patients with co-morbidities achieved a successful outcome versus 81% of patients with no co-morbidities, but this difference in proportions was not statistically significant (p=0.46). Active patients (HLA, REC, ACT) were significantly (p=0.023) and 4.5 times more likely to have a successful outcome than minimally active or sedentary patients. Patients with BMI <30 were 3.7 times more likely to have a successful result and the difference was significant (p=0.011). Smoking, workman's compensation, OCA-related revision surgery, lesion location and number of grafts placed did not have statistically significant effects on outcome. CONCLUSION: Osteochondral allograft transplantation can be a successful treatment option for large cartilage defects in the knee with patients having no intra-articular co-morbidities achieving an 81% success rate. Patients who are more active preoperatively and those with BMI <30 were significantly more likely to have successful outcomes.