Fresh osteochondral allografts in the knee: comparison of primary transplantation versus transplantation after failure of previous subchondral marrow stimulation.

Background: In most treatment algorithms, osteochondral allograft (OCA) transplantation is regarded as an alternative salvage procedure when other, previous reparative treatments have failed.

Purpose: To compare the outcomes of a retrospective matched-pair cohort of (1) primary OCA transplantation and (2) OCA transplantation after failure of previous subchondral marrow stimulation.

Study Design: Cohort study; Level of evidence, 3.

Methods: An OCA database was used to identify 46 knees that had OCA transplantation performed as a primary treatment (group 1) and 46 knees that underwent OCA transplantation after failure of previous subchondral marrow stimulation (group 2). All patients had a minimum of 2 years' follow-up. Patients in each group were matched for age (±5 years), diagnosis (osteochondral lesion, degenerative chondral lesion, traumatic chondral injury), and graft size (small, <5 cm2; medium, 5-10 cm2; large, >10 cm2). The groups had similar body mass indexes, sex distributions, and graft locations (femoral condyle, patella, and trochlea. The number and type of further surgeries after the OCA transplantation were assessed; failure was defined as any reoperation resulting in removal of the graft. Functional outcomes were evaluated by use of the modified Merle d'Aubigné-Postel (18-point) scale, International Knee Documentation Committee (IKDC) subjective knee evaluation form, Knee injury and Osteoarthritis Outcomes Score (KOOS), and the Knee Society function (KS-F) scale. Patient satisfaction, according to a 5-point scale from "extremely satisfied" to "dissatisfied," was recorded at the latest follow-up.

Results: Eleven of 46 knees (24%) in group 1 had reoperations, compared with 20 of 46 knees (44%) in group 2 (P = .04). The OCA was classified as a failure in 5 knees (11%) in group 1 and 7 knees (15%) in group 2 (P = .53). At 10 years of follow-up, survivorship of the graft was 87.4% and 86% in groups 1 and 2, respectively. Both groups showed improvement in pain and function on all subjective scores from preoperatively to the latest follow-up (all P < .001). Results showed that 87% of patients in group 1 and 97% in group 2 were "satisfied" or "extremely satisfied" with the OCA transplantation.

Conclusion: Favorable results were shown in both groups with significant improvement of functional scores and excellent survivorship. Despite the higher reoperation rate in the previously treated group, previous subchondral marrow stimulation did not adversely affect the survivorship and functional outcome of OCA transplantation.