Relationship between SLAP Lesions and Shoulder Joint Capsule Thickness: An MR Arthrographic Study

<i>Background and Objectives:</i> This study aimed to evaluate the relationship between SLAP lesions and the shoulder joint capsule thickness via MR arthrography. Understanding the relationship between SLAP lesions and the joint capsule thickness is important because an increased capsule thickness may indicate chronic inflammation and contribute to persistent pain and dysfunction. These findings have significant clinical implications for the diagnosis, management, and treatment strategies of shoulder joint pathologies. <i>Materials and Methods:</i> We retrospectively analyzed the MR arthrography results of 78 patients who underwent shoulder imaging at Düzce University Medical Faculty between October 2021 and November 2024. The study included patients diagnosed with SLAP lesions and compared them with a control group without such pathology. Data on joint capsule thickness at the level of the axillary recess, SLAP lesion type, cuff pathology, and demographic information were collected and analyzed. <i>Results:</i> The study included 32 patients with SLAP lesions and 46 control subjects. The mean age of the patients was 44.75 ± 14.18 years, whereas the control group had a mean age of 38.76 ± 13 years. The patient group presented a significantly greater mean anterior capsule thickness (3.13 ± 1.28 mm vs. 1.72 ± 0.7 mm, <i>p</i> = 0.0001), posterior capsule thickness (3.35 ± 1.32 mm vs. 1.95 ± 1.06 mm, <i>p</i> = 0.0001), and maximum capsule thickness (3.6 ± 1.32 mm vs. 2.06 ± 1.01 mm, <i>p</i> = 0.0001) in the axillary recess. SLAP type 2 lesions were the most common type (43.76%) in the patient group. <i>Conclusions:</i> This study revealed a significant association between SLAP lesions and an increased shoulder joint capsule thickness. These findings suggest that MR arthrography is an effective tool for assessing the joint capsule changes associated with labral tears, contributing to the better diagnosis and management of shoulder joint pathologies in clinical practice.