Multicompartmental Osteochondral Allografts of Knee and Concomitant High Tibial Osteotomy

The Large Focal Isolated Chondral Lesion

Focal chondral defects (FCDs) of the knee can be a debilitating condition that can clinically translate into pain and dysfunction in young patients with high activity demands. Both the understanding of the etiology of FCDs and the surgical management of these chondral defects has exponentially grown in recent years. This is reflected by the number of surgical procedures performed for FCDs, which is now approximately 200,000 annually. This fact is also apparent in the wide variety of available surgical approaches to FCDs. Although simple arthroscopic debridement or microfracture are usually the first line of treatment for smaller lesions, chondral lesions that involve a larger area or depth require restorative procedures such as osteochondral allograft transplantation or other cell-based techniques. Given the prevalence of FCDs and the increased attention on treating these lesions, a comprehensive understanding of management from diagnosis to rehabilitation is imperative for the treating surgeon. This narrative review aims to describe current concepts in the treatment of large FCDs through providing an algorithmic approach to selecting interventions to address these lesions as well as the reported outcomes in the literature.

Patient-Reported Outcomes for Large Bipolar Osteochondral Allograft Transplantation in Combination with Realignment Osteotomies for the Knee

Effective treatment for bipolar articular cartilage lesions in the knee remains a clinical challenge. Lower extremity malalignment is a risk factor for treatment failures, which can be addressed by tibial or femoral osteotomy. The purpose of this study was to compare outcomes among patients who underwent knee joint restoration by osteochondral allograft (OCA) transplantation with concurrent or staged realignment osteotomy. With Institutional Review Board approval, patients undergoing bipolar OCA transplantation with concurrent or staged distal femoral osteotomy (DFO) or high tibial osteotomy (HTO) were analyzed. Patients were categorized by osteotomy type (DFO and HTO) and timing (concurrent and staged). Patient-reported outcome measures (PROMs), revisions, failures, and complications were examined preoperatively (baseline), 3, 6, 12, and 24 months after OCA transplantation; change scores from preoperative values were used for analysis. A total of 23 patients met inclusion criteria (15 males); 13 (56.5%) received HTO (5 concurrent), while 10 (43.5%) received DFO (5 concurrent). There were no significant differences in complication rates between concurrent and staged osteotomies. Primary bipolar OCA transplantation with osteotomy was associated with successful outcomes in 70% of patients; four patients underwent revision (17.4%) and three (13.0%) failed and were treated by total knee arthroplasty. Further, the four patients undergoing revision met functional criteria for success at final follow-up, resulting in a 2-year functional survival rate of 87.4%. Aside from Patient-Reported Outcomes Measurement Information System (PROMIS) physical function, all PROMs for concurrent and staged osteotomies improved from baseline to 2 years postoperatively. Concurrent osteotomies of both types were associated with significantly lower pain scores at 12 months (p = 0.04), compared with staged osteotomies. Apart from Single Assessment Numerical Evaluation (SANE), more PROM improvement was observed for concurrent osteotomies at 2 years. Improvements in PROMs for patients undergoing OCA transplantation combined with osteotomy were observed at 2-year follow-up. PROMs for concurrent osteotomy were consistently greater than staged osteotomy, lending support to addressing lower extremity malalignment with bipolar OCA transplantation in the knee during a single surgery when possible.