Effect of subchondral bone sclerosis in repair tissue after bone marrow stimulation for osteochondral talar lesions

Abstract

Category: Arthroscopy Introduction/Purpose: The arthroscopic bone marrow stimulation (ABMS) technique is the first-line procedure for the treatment of osteochondral lesions of the talus (OLT). Recently, T2 mapping was used to evaluate repair cartilage tissue, but the prognostic factors for T2 values after ABMS have never been clarified. Some patients have OLT with sclerotic changes in the subchondral bone, and several articles have suggested that the subchondral bone condition affects the condition of the articular cartilage. Furthermore, subchondral bone sclerosis (SBC) was found to be associated with an inferior outcome after ABMS.The purpose of this study was to investigate the relationship between subchondral bone sclerotic changes and repair tissue T2 values on MRI after ABMS. Methods: Twenty ankles in 20 patients treated with ABMS for OLT were evaluated. The patients included 7 males and 13 females (age, 30.52±21.44 years, lesion length 10.4±3.0mm, lesion area 55.7±26.5mm2). Repair tissue was assessed using a 3T MRI unit, and T2 maps were calculated at the one-year post-ABMS follow up. The patients were divided into two groups; with SBC and without SBC on pre-ABMS CT images. We investigated the relationship between T2 values and SBC. Clinical results were measured using the Japanese Society for Surgery of the Foot (JSSF) Ankle-Hindfoot Scale. Results: No significant mean differences were found in T2 values or JSSF scores between the with SBC and without SBC groups post-ABMS (T2 values; 48.2±3.3ms vs. 50.1±2.9ms, P=0.7 / JSSF scale score; 89.4±5.8 points vs. 93.3±8.2 points, P=0.25). Lesion length was correlated with the T2 values of repair tissue (Length; r=0.3 P=0.01). Age and BMI were not significantly correlated with T2 values of the repair tissue. Conclusion: The presence of SBC prior to ABMS did not affect the T2 values of repair tissue after ABMS. However, we believe that lesion size affected the condition of the repair tissue.