39 – MEAN 20 YEARS FOLLOW UP FOR DISTAL FEMUR FRESH OSTEOCHONDRAL ALLOGRAFTED PATIENTS – PROSPECTIVE STUDY

Abstract

Purpose: An Osteochondral defect in the knees of young active patients represents a challenge to the orthopedic surgeon. Early studies on allogenic cartilage transplantation showed this tissue to be immunologically privileged, showed fresh grafts to have hyaline cartilage, and surviving chondrocytes present several years after implantation.

Method: Since January 1978 until October 1995 we enrolled 72 patients in a prospective non-randomized study of fresh osteochondral allografts in our institute. Ten international patients which were lost to follow-up were excluded. The major indications for the procedure were: patients younger than 60 years of age having post-traumatic unipolar defects larger than three cm in diameter and one cm in depth.

Results: Sixty two patients, ages 11–57 (mean 28) were followed for 15–31 years (mean 20.4 years). The etiology for the osteochondral defect was traumatic injury to the knee in 41 patients (66%), Osteochondritis Dissecans in 15 patients (24%), and in six patients (10%) due to other pre-existing conditions. Twenty of the 62 grafts have failed, with five having graft removal and 15 converted to total knee replacement. Three patients died during the course of this study due to unrelated causes. The Kaplan-Meier survivorship analysis showed: 92%, 79%, 56%, and 49% graft survival at 10, 15, 20, and 25 years respectively, (median survival = 23 years). Patients with surviving grafts had good function, with a modified Hospital for Special Surgery score of an average 88 at 20 years or more following the allograft transplantation surgery.

Conclusion: Through this long term study the authors confirm the value of fresh osteochondral allografts as a long term solution for large articular defects in the knees of young patients. The improvement of patients’ outcome compared to the previous published results of our earlier studies could be attributed to improved surgical techniques and increasing expertise of the senior authors. We therefore recommend the use of fresh osteochondral allografts for treatment of large osteochondral defects in the distal femur of young and active patients.