Current concepts review in the management of subscapularis tears

Arthroscopic management of isolated partial-thickness rotator cuff tears

PURPOSE

The aim of the present study is to provide a comprehensive review on the surgical outcomes following arthroscopic treatments of partial-thickness rotator cuff tears (PT-RCTs) and to compare the postoperative American Shoulder and Elbow Surgeons (ASES) score following in situ transtendon repair and tear completion, followed by repair.

METHODS

Medline, EMBASE, Scopus, CINAHL and CENTRAL bibliographic databases were searched. Papers including patients with PT-RCTs of any grade who underwent treatment using debridement, in situ transtendon repair, tear completion and repair or bioinductive collagen implants were reviewed. Primary PT-RCTs were the sole indication for surgery. Primary postoperative outcomes assessed included the ASES score, the Absolute Constant-Murley score, the Simple Shoulder Test, the Visual Analogue Scale, the University of California-Los Angeles Shoulder Scale, the Western Ontario Rotator Cuff Score, range of motion, complications and revisions. A meta-analysis of comparative studies compared the postoperative ASES score between patients treated with in situ transtendon repair versus tear completion repair.

RESULTS

Twenty-eight studies were included. The ASES score was reported by four comparative studies with contrasting results. The heterogeneity was high (I2 = 86%), and effect sizes ranged from -0.49 in favour of the tear completion and repair technique to an effect size of +1.07 favouring in situ transtendon repair. The overall effect size of 0.02 suggests an equivalence between the two techniques in terms of the ASES score. Two studies with a total sample size of 111 patients reported on debridement, and four studies with a total sample size of 155 patients reported on bioinductive collagen implants.

CONCLUSION

Debridement alone is suitable for Ellman grades I-II PT-RCTs. In situ transtendon and tear completion repair techniques yield similar postoperative outcomes. Bioinductive collagen implants hold promise but lack long-term efficacy data. High-quality comparative studies are needed to determine the best treatment for PT-RCTs.

LEVEL OF EVIDENCE

Level IV.

Partial Subscapularis Tear: State-of-the-Art

The Subscapularis (SSC) muscle is a crucial anterior glenohumeral stabilizer and internal rotator of the shoulder joint. The partial tears of the SSC might result from traumatic injury or intrinsic degeneration. Partial SSC tears can range in severity and be classified into different categories based on the location of the tear, size of the lesion, and associated pathology. The tear usually begins from the superolateral margin in the first facet and propagates downwards. It is frequently associated with biceps pathology or anterosuperior lesions. These tears are now increasingly recognized as distinct pathology that requires specific diagnostic and management approaches. The current management approaches are shifting towards operative, as partial SSC tears are increasing recognized as distinct pathology. At present, there is no consensus regarding the timing of repair, but the relative tendency of the SSC to retract much faster than other rotator cuff muscles, and difficulty in mobilization, advocates an early repair for SSC irrespective of the lesion size. An associated biceps pathology can be treated with either tenotomy (biceps delamination/erosion) or tenodesis. The techniques of partial SSC repair are constantly improving. There is no reported difference in use of 2-anchor-based conventional single-row (SR), a 3-anchor-based interconnected double-row technique, or a 2-anchor-based interconnected hybrid double-row construct in the repair construct. However, the 2-anchor-based interconnected double-row provides an advantage of better superolateral coverage with the leading-edge protection, as it helps in placing the superolateral anchor superior and lateral to the original footprint. A timely intervention and restoration of the footprint will help restore and rehabilitate the shoulder. Future directions should prioritise injury prevention, early diagnosis with clinic-radiological cues and targeted interventions to mitigate risk.

Diagnostic Performance of Belly-Press Angle in Predicting the Severity of Subscapularis Tear

BACKGROUND

Neglected partial subscapularis tears often cause functional impairment even after repair of the supraspinatus and infraspinatus tear is done. Numerous physical examinations for detecting partial subscapularis tears have been described in previous studies.

PURPOSE

To analyze the relationship between the preoperative clinical features and the severity of a partial subscapularis tear and to provide diagnostic clues for patients requiring subscapularis repair.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

This retrospective study included 286 patients who underwent arthroscopic shoulder surgery between 2020 and 2022. Preoperative clinical features, including range of motion, functional scores, muscle strength ratio, modified belly-press test (measuring belly-press angle), and bear-hug test, were collected. Magnetic resonance imaging (MRI) evaluation was done according to the Yoo and Rhee classification. Types of subscapularis tear, supraspinatus lesion, and biceps lesion were recorded during arthroscopic surgery. A comparison of preoperative clinical features between the no-repair group (type 2A or less) and surgical repair group (type 2B or more) was done. The optimal cutoff value of the belly-press angle was determined and the diagnostic performance of the belly-press angle, bear-hug test, and MRI were evaluated using the receiver operating characteristic curve.

RESULTS

Among 286 patients, 189 (66.1%) had subscapularis tears with type 2A or more. There was a significant difference in muscle strength ratio of the belly-press (P < .001), belly-press angle (P < .001), and bear-hug test (P < .001) between the no-repair group (type 2A or less) and the surgical repair group (type 2B or more). With a belly-press angle of 15° as a new cutoff value, the modified belly-press test showed 67.6% sensitivity, 73.9% specificity, and 69.6% accuracy in detecting type 2B or higher subscapularis tear.

CONCLUSION

Patients with type 2A and 2B subscapularis tears (according to the Yoo and Rhee classification) showed differences in belly-press strength ratio, belly-press angle, and bear-hug test. The cutoff value of the 15° belly-press angle showed an accuracy of 69.6% in detecting subscapularis tears with type 2B or higher.

The prevalence, classification, radiological and arthroscopic findings of intratendinous subscapularis tears

PURPOSE

To investigate the clinical characteristics of intratendinous subscapularis (inSSC) tears.

METHODS

Retrospectively, 69 patients with arthroscopically confirmed inSSC tears were identified from 2018 to 2019. Preoperatively and at final follow-up, thorough physical examination was performed and clinical outcomes (American Shoulder and Elbow Surgeons [ASES] score; University of California, Los Angeles [UCLA] score; visual analogue scale [VAS] for pain; and Simple Shoulder Test [SST]) were recorded. Features of pre-operative magnetic resonance image (MRI) such as high signalling within the tendon substance, communication to the bicipital groove and long head of biceps tendon (LHBT) lesions were investigated. Characteristics of arthroscopic view were investigated. Bear-hug and internal rotation resistance test at 90° abduction and external rotation (IRRT90°) test were used to assess the SSC strength.

RESULTS

The mean follow-up was 2.4 (2-3) years. The prevalence of arthroscopically confirmed inSSC tears was 69/675 (10.2%) among arthroscopic rotator cuff repairs. Pre-operative physical examination found positive IRRT90° and bear-hug test in 41/60 (68.3%) and 42/69 (60.8%) patients, respectively. The Cohen kappa coefficient was interpreted to be substantial for the evaluation of all MRI parameters. According to the conditions of LHBT, inSSC tears were classified into 3 types: type I: without LHBT subluxation and tear; type II: with LHBT subluxation or tears and type III: with LHBT dislocation. At final follow-up, mean ASES, UCLA, VAS, and SST scores improved significantly from mean of 50.6 ± 14.7, 19.4 ± 3.07, 6.2 ± 2.0, and 6.1 ± 2.5 to mean of 90.7 ± 9.5, 32.2 ± 1.8, 1.4 ± 1.2 and 9.8 ± 2.2, respectively (P < 0.001). Bilateral symmetric strength was found by bear-hug and IRRT90° test in all patients postoperatively.

CONCLUSION

Understanding features of pre-operative MRI, physical examination and arthroscopic view is helpful to identify inSSC tears. Arthroscopic repair yielded satisfactory clinical outcomes in patients with inSSC tears.

LEVEL OF EVIDENCE

Level IV.