Improved Outcomes with Arthroscopic Bone Marrow Aspirate Concentrate and Cartilage-Derived Matrix Implantation versus Chondroplasty for the Treatment of Focal Chondral Defects of the Knee Joint: A Retrospective Case Series

PURPOSE: To compare the outcomes of patients undergoing treatment of focal chondral defects (FCDs) of the knee joint with chondroplasty versus bone marrow aspirate concentrate (BMAC) and cartilage-derived matrix (CDM) implantation. METHODS: A retrospective chart review was performed for patients diagnosed with Outerbridge grade 3-4 FCDs. Patients were included if they were treated arthroscopically with BMAC/CDM implantation or chondroplasty alone between March 2016 and May 2019 and had more than 1-year follow-up. Postoperative outcomes included the visual analog scale (VAS) for pain; University of California, Los Angeles (UCLA) activity scores; Knee Outcome Survey (KOS) Activities of Daily Living (ADL) and Sports subscores; postoperative corticosteroid or hyaluronic acid injections; subsequent surgeries; and conversion to total knee arthroplasty. RESULTS: A total of 98 patients were identified with a mean follow-up in BMAC/CDM of 24 months (range 13-41 months) and in chondroplasty of 44 months (range 34-55 months). A subanalysis was performed to control for significant differences in age, which yielded 39 patients, ages 40-60 years. Within the subanalysis group, mean VAS scores were significantly lower in the BMAC/CDM group (1.7 vs 4.4; P = .005) and mean UCLA scores were significantly greater (7.1 vs 5.0; P = .002). Mean improvement in VAS and UCLA scores were similar between the BMAC/CDM and chondroplasty groups (–3.7 vs –1.3; P = .71, 1.9 vs 0.1; P = .14, respectively). Mean KOS ADL and Sports subscores were significantly greater among patients in the BMAC/CDM group (87% vs 55%; P = .001, 71% vs 41%; P = .002, respectively). There were no differences in postoperative injections, subsequent surgeries, or conversion to total knee arthroplasty between the BMAC/CDM and chondroplasty groups. CONCLUSIONS: Patients with grade 3-4 FCDs of the knee had improved postoperative outcomes when treated with BMAC/CDM implantation versus chondroplasty alone, as evidenced by a significant improvement in VAS and UCLA scores and significantly greater postoperative KOS ADL, and KOS Sport subscores. LEVEL OF EVIDENCE: IV, therapeutic case series.