Exploring Factors Causing Damage to Articular Cartilage Due to Curettage in Subchondral Region: Is There Any Effect of Adjuvant Therapies?

This study investigated the factors that cause articular cartilage damage after subchondral curettage. Twenty-six male New Zealand White rabbits were divided into four groups: A (control), B (bone cementation post-curettage), C (phenol post-curettage), and D (phenol and bone cementation post-curettage). Each group had 13 knees treated similarly. The rabbits were monitored for 8 weeks postoperatively. A lateral subchondral bone window was created, after which the curettage procedure was performed. Serum cartilage oligomatrix protein (COMP) levels were analyzed before and after the procedure. At week eight, Magnetic Rezonance Imaging (MRI) was performed on both knees. Cartilage deterioration was assessed using OARSI cartilage. Fibrillation index and cartilage thickness were measured histopathologically. The lateral condyle cartilage thickness was lower than the medial thickness in all regions on the MRI. No significant differences were observed in the femoral condyle of the control group; however, differences were found in the other groups. Serum COMP levels increased at week 8 but were not significant, with no differences across the groups before (p = 0.507) or after (p = 0.199). The lateral condyle had a higher OARSI grade, stage, and total scores than the medial condyle (p < 0.001). Significant differences between the lateral and medial condyle in the OARSI scores were found between the phenol, cement, and phenol+cement groups (p = 0.014, p = 0.019, and p = 0.006, respectively). The lateral condyle showed a higher fibrillation index and lower cartilage thickness than the medial condyle (p < 0.001). Adjuvant therapy after curettage causes more subchondral cartilage damage. Changes in the subchondral bone microenvironment resulting from curettage and adjuvant therapies affect cartilage metabolism and contribute to osteoarthritis-related degradation.