Identifying key factors associated with subscapularis tendon tears and developing a risk prediction model to assist diagnosis

Abstract

Background There are still some challenges in diagnosing subscapularis (SSC) tendon tears as accurately as posterosuperior rotator cuff tears on MRI. The omission of SSC tendon tear can lead to muscle atrophy, fatty infiltration, and increased tearing accompanied by aggravated shoulder pain and loss of function. An effective non-invasive evaluation tool will be beneficial to early identification and intervention. The study aims to identify sensitive predictors associated with SSC tendon tears and develop a risk prediction model to assist in diagnosis. Methods Data on 660 patients who received shoulder arthroscopic surgery with preoperative shoulder MRI were collected retrospectively. Of these, patients with SSC tendon tears were defined as the SSC tear group, and patients with intact SSC tendon were enrolled in the non-SSC tear group. Logistic regression analysis was used to identify the key predictors of SSC tendon tears which were then incorporated into the nomogram. Results Among 22 candidate factors, five independent factors including coracohumeral distance (CHD, oblique sagittal plane) (OR, 0.75; 95%CI, [0.67–0.84]), fluid accumulation (Y-face) (OR, 2.29; 95%CI, [1.20–4.38]), long head of biceps tendon (LHB) dislocation/subluxation (OR, 3.62; 95%CI, [1.96–6.68]), number of posterosuperior (PS) rotator cuff tears (OR, 5.36; 95%CI, [3.12–9.22]), and MRI diagnosis (based on direct signs) (OR, 1.88; 95%CI, [1.06–3.32]) were identified as key predictors associated with SSC tendon tears. Incorporating these predictors, the nomogram achieved a good C index with a good agreement on the risk estimation of calibration plots. Higher total points of the nomogram were associated with a greater risk of SSC tendon tears. Conclusion When evaluating the severity of SSC tendon injury, the combination of reliable predictors can improve the sensitivity and diagnostic performance of MRI. This model provides an individualized probability of risk prediction, which is convenient for clinicians to identify patients at high risk for SSC tendon tears to avoid missed diagnosis.

Preoperative Shoulder MRI Findings to Predict Subscapularis Tendon Tear Requiring Surgical Repair

“…Surgical repair of STT was not an uncommon procedure during arthroscopy for rotator cuff tears, accounting for 36.0% (31/86) of the patients. Detecting these clinically significant STT using MRI is challenging because of the low sensitivity of 48.4%, similar to the results of previous studies ( 7 10 17 ).…”

“…Two readers (a dedicated musculoskeletal radiologist with 24 years of experience and a third-year radiology resident) independently interpreted or measured the MR parameters and resolved all disagreements by consensus. Candidate parameters included MRI diagnoses based on visual assessments using all suspicious direct signs such as alterations in signal intensity, thickness changes, and musculotendinous retraction ( 10 12 ). If an STT was present, it was evaluated for surgical repair.…”

“…A recent systematic review and meta-analysis demonstrated unclear sensitivity of MRI for detecting STT, ranging from 25% to 94% with an overall sensitivity of 68% ( 9 ). However, this overall sensitivity was overestimated because more than half of the studies included in this review used MR arthrography ( 10 ). Although the recognition of STT during arthroscopy has improved, and surgical outcomes are good, the current diagnostic performance of preoperative MRI is not ideal ( 11 ).…”

Clinical Approach to Inconclusive Subscapularis Tear Diagnosis: a Meta-analysis

“…Leite et al, suggested that the optimal sensitivity and specificity for predicting SSC tears was a CHD of 7.95 mm [13]. Xu et al, and Seo et al showed that a decreased CHD was closely related to SSC tears and had high predictive value and diagnostic sensitivity [17,25]. According to Zhu et al, there was a significant difference between affected and contralateral CHD in patients with SSC tears, and the bilateral discrepancy (ΔCHD) was closely related to SSC tears and subcoracoid impingement [9].…”

“…LHB injury was reported in three studies [6,15,17]. There were 907 patients included, with 283 patients in the experimental group and 624 patients in the control group.…”