Long-term follow-up of fresh tibial osteochondral allografts for failed tibial plateau fractures.

BACKGROUND: The management of large posttraumatic full-thickness osteochondral defects in the proximal part of the tibia remains a challenge. The goal of treatment is a pain-free range of motion of the knee that provides enduring function and enables a young patient to participate in a wide range of activities. The use of fresh osteochondral allograft transplantation for tibial plateau lesions has been well documented. The purpose of the present study was to assess the survivorship and the long-term functional outcome following fresh osteochondral transplantation for unipolar posttraumatic tibial plateau defects in young, high-demand patients.
METHODS: A cohort study was carried out to assess outcome in patients who had undergone fresh tibial osteochondral grafting for the treatment of a posttraumatic defect that measured at least 3 cm in diameter and 1 cm in depth. Sixty-five (97%) of sixty-seven patients were identified and were evaluated clinically and radiographically. A modified Hospital for Special Surgery (HSS) score was calculated for each patient. Radiographic examination was directed toward the identification of graft union, resorption, or collapse. Degeneration of the joint and alignment of the limb (on standing radiographs) was assessed. The end points that defined survivorship were an HSS score of <70 points, a patient's decision to undergo knee arthroplasty, or revision of the graft for any reason.
RESULTS: At a mean of twelve years, forty-four patients had an intact graft and twenty-one had had conversion to a total knee arthroplasty. The mean modified HSS Score for the patients with an intact graft was 85 points. Radiographs, reviewed for thirty-five of the forty-four patients with an intact graft, revealed union of the graft to host bone in all cases and an 8.6% prevalence of graft collapse in excess of 3 mm. Forty percent of these thirty-five patients demonstrated moderate to severe degenerative changes. Kaplan-Meier survivorship analysis showed that the survival rate was 95% at five years, 80% at ten years, 65% at fifteen years, and 46% at twenty years. A trend toward increased survivorship (p = 0.08) was seen among patients who had undergone meniscal transplantation in conjunction with osteochondral grafting.
CONCLUSIONS: Fresh osteochondral allografts for large traumatic defects of the tibial plateau have provided a long-lasting and reliable reconstructive solution for a high-demand population. Meniscal allografts should be used when clinically warranted. In the present study, all grafts were protected with a coincident realignment osteotomy when preoperative radiographs suggested that the allograft would be placed under increased load. Conversion to knee arthroplasty was required for approximately one-third of the patients at an average of ten years.