Background: Autologous osteochondral transplantation is accepted as one of the major treatment options for cartilage defects of the talus. One disadvantage of this technique is the need to harvest a donor graft from a normal knee. The potentially detrimental effect of graft harvest on knee function remains unclear.
Methods: Two hundred patients who had transplantation of an autologous osteochondral graft obtained from an asymptomatic knee for the treatment of an osteochondral defect of the talus were evaluated. Of the 200 patients, 112 were followed for a minimum of two years (mean duration of follow-up, fifty-five months). The WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and the Lysholm score were used to assess functional outcome. Variables that were examined included the number of grafts, total size of the harvested cylinders, patient age, body mass index, and overall satisfaction of the patient with the result of the procedure at the knee. A multiple linear regression analysis was utilized to determine the influence of each parameter on the WOMAC and Lysholm scores. In addition, the Lysholm scores for the entire patient group were reviewed to determine how long after the index surgery clinical improvement ceased.
Results: The mean postoperative WOMAC score (and standard deviation) for the 112 patients who had been followed for a minimum of two years was 5.5% ± 0.1%, and the mean postoperative Lysholm score was 89 ± 17 points. The number of grafts, the size of the transplanted cylinders, and patient age did not influence either the Lysholm or the WOMAC score. A higher body mass index and lower general satisfaction ratings did negatively influence the Lysholm and WOMAC scores. Gradual clinical improvement, as measured with the Lysholm score for all 200 study subjects, continued throughout the postoperative period.
Conclusions: Donor-site morbidity of a knee from which a graft has been harvested can potentially lead to functional impairment. In our study, the functional outcome of the knee was not affected by the number of donor grafts, the size of the donor grafts, or the age of the patient. Surgeons performing osteochondral transplantations and harvesting autografts from the knee should be aware of the potentially negative effect of a higher body mass index on clinical outcomes after surgery.
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.