Prospective Assessment of Outcomes After Primary Unipolar, Multisurface, and Bipolar Osteochondral Allograft Transplantations in the Knee: A Comparison of 2 Preservation Methods.

BACKGROUND

Articular cartilage lesions in the knee remain a challenging clinical problem.

HYPOTHESIS

A novel graft preservation method combined with surgical technique and patient management improvements would lead to consistently successful outcomes after osteochondral allograft (OCA) transplantation.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

With institutional review board approval and informed consent, patients were prospectively enrolled into a registry to follow outcomes after OCA transplantation. Patients were included when ≥1-year follow-up data were available, including complications and reoperations, patient-reported outcome measures (PROMs), compliance with rehabilitation, revisions, and failures.

RESULTS

For patients meeting inclusion criteria (N = 194), mean ± SD age was 37.9 ± 12.2 years and mean BMI was 28.9 ± 5; 38% received unipolar transplants (44% multisurface) and 62% received bipolar transplants. OCAs were preserved by standard tissue bank methods (standard preservation [SP]; 29%) or the novel method (Missouri Osteochondral Preservation System [MOPS]; 71%). Initial success rates were 79% for all cases combined, 60% for SP, and 84% for MOPS. MOPS cases were significantly ( = .028) more likely to be associated with successful outcomes when compared with SP cases. PROMs improved significantly ( < .05) for all cohorts through 3 to 4 years of follow-up. Revisions were performed in 19 cases (10%). MOPS grafts were associated with a significantly ( = .0014) lower revision rate (5%) than SP grafts (21%). Failures occurred in 26 patients (13%), with all undergoing total knee arthroplasty. Bipolar cases were significantly ( = .008) more likely to be associated with failure. MOPS grafts were associated with a significantly ( = .048) lower failure rate (11%) than were SP grafts (19%). Noncompliance with the prescribed rehabilitation protocol was significantly ( = .00008) more likely to be associated with failure.

CONCLUSION

Prospective data for 194 cases revealed that OCA transplantation for unipolar, multisurface, and bipolar cartilage restoration can be associated with consistently successful outcomes. The 5% revision rate, 11% failure rate, 82%-94% survival probability estimates, and continually improving PROMs through postoperative 3 to 4 years underscore major advances in outcomes as compared with previous reports. These encouraging results were realized with the use of a novel graft preservation method; autogenous bone marrow concentrate pretreatment of donor bone; advancements in graft cutting, implantation, and stabilization techniques; and procedure-specific rehabilitation protocols.