Internal rotation resistance test at abduction and external rotation: a new clinical test for diagnosing subscapularis lesions

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.

Diagnostic Accuracy of Clinical Tests for Subscapularis Tears: A Systematic Review and Meta-analysis

Background:

Previous systematic reviews and meta-analyses on the diagnostic accuracy of shoulder clinical tests do not reach conclusions regarding subscapularis tears.

Purpose:

To compare the diagnostic accuracy of commonly used clinical tests for subscapularis tears.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

An electronic literature search was conducted using Medline, Embase, and the Cochrane Library/Central. Eligibility criteria were original clinical studies reporting the diagnostic accuracy of clinical tests to diagnose the presence of rotator cuff tears involving the subscapularis.

Results:

The electronic literature search returned 2212 records, of which 13 articles were eligible. Among 8 tests included in the systematic review, the lift-off test was most frequently reported (12 studies). Four tests were eligible for meta-analysis: bear-hug test, belly-press test, internal rotation lag sign (IRLS), and lift-off test. The highest pooled sensitivity was 0.55 (95% CI, 0.28-0.79) for the bear-hug test, while the lowest pooled sensitivity was 0.32 (95% CI, 0.13-0.61), for the IRLS. In all tests, pooled specificity was >0.90.

Conclusion:

Among the 4 clinical tests eligible for meta-analysis (bear-hug test, belly-press test, IRLS, and lift-off test), all had pooled specificity >0.90 but pooled sensitivity <0.60. No single clinical test is sufficiently reliable to diagnose subscapularis tears.

Registration:

PROSPERO (CRD42019137019).

Bilateral coracohumeral distance discrepancy is associated with subscapularis tear in rotator cuff rupture patients

PURPOSE

To describe the bilateral coracohumeral morphological discrepancy in rotator cuff rupture patients with and without subscapularis (SSC) involvement and to investigate its association with SSC tears.

METHODS

Two hundred and thirteen consecutive patients who were scheduled to have arthroscopic rotator cuff repair were prospectively enrolled in the current study. Patients with acute traumatic rotator cuff rupture, glenohumeral osteoarthritis, bilateral rotator cuff rupture, recurrent shoulder instability, systemic inflammatory disease, and previous shoulder surgery history were excluded. Coracohumeral distance (CHD), coracoid overlap (CO), lesser tuberosity index (LTI) and acromiohumeral interval (AHI) were measured bilaterally using CT scans. Based on arthroscopic findings, patients were included in either the SSC tear group (n = 72) or the control group (n = 141).

RESULTS

In the SSC tear group, the affected shoulder possessed a significantly smaller CHD [95% confidence interval (CI) 6.1-7.2 vs. 7.2-8.0 mm, p < 0.0001], larger LTI (95% CI 9.4-9.9 vs. 9.0-9.6 mm, p < 0.0001), and smaller AHI (95% CI 5.0-5.5 vs. 7.1-7.5 mm, p < 0.0001) than the contralateral normal shoulder. In the control group, there was no significant difference between bilateral CHD and CO, and the AHI bilateral discrepancy was less distinct. CO did not differ significantly in the bilateral comparison in either group. Among all evaluated parameters, bilateral CHD discrepancy was the best predictor of SSC tears, with an area under the curve (AUC) of 0.882. A cutoff value of 0.5 mm had a sensitivity of 76.4% and specificity of 99.3% for SSC tears.

CONCLUSION

The CHD values are significantly different between affected and contralateral shoulders in SSC tear patients. Bilateral CHD discrepancy is closely associated with subcoracoid impingement and SSC tears, and its presence warrants specific intraoperative SSC inspection.

LEVEL OF EVIDENCE

Level II.

Evidence-Based Physical Examination for the Diagnosis of Subscapularis Tears: A Systematic Review

CONTEXT

There is a renewed interest in diagnosing and treating subscapularis tears, but there is a paucity of clinical guidance to optimize diagnostic decision-making.

OBJECTIVE

To perform a literature review to evaluate advanced maneuvers and special tests in the diagnosis of subscapularis tears and create a diagnostic algorithm for subscapularis pathology.

DATA SOURCES

PubMed, MEDLINE, Ovid, and Cochrane Reviews databases.

STUDY SELECTION

Inclusion criteria consisted of level 1 and 2 studies published in peer-reviewed scientific journals that focused on physical examination.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 2.

DATA EXTRACTION

Individual test characteristics (bear hug, belly press, lift-off, Napoleon, and internal rotation lag sign) were combined in series and in parallel to maximize clinical sensitivity and specificity for any special test evaluated in at least 2 studies. A secondary analysis utilized subjective pretest probabilities to create a clinical decision tree algorithm and provide posttest probabilities.

RESULTS

A total of 3174 studies were identified, and 5 studies met inclusion criteria. The special test combination of the bear hug and belly press demonstrated the highest positive likelihood ratio (18.29). Overall, 3 special test combinations in series demonstrated a significant impact on posttest probabilities. With parallel testing, the combination of bear hug and belly press had the highest sensitivity (84%) and lowest calculated negative likelihood ratio (0.21).

CONCLUSION

The combined application of the bear hug and belly press physical examination maneuvers is an optimal combination for evaluating subscapularis pathology. Positive findings using this test combination in series with a likely pretest probability yield a 96% posttest probability; whereas, negative findings tested in parallel with an unlikely pretest probability yield a 12% posttest probability.

A Comprehensive Review of Physical Examination Tests of the Cervical Spine, Scapula, and Rotator Cuff

A thorough physical examination of the shoulder and cervical spine is critical in establishing a focused differential diagnosis of the pathology in and around the shoulder joint. Numerous tests have been described in the literature to help improve the diagnostic accuracy of specific shoulder or cervical spine pathology. A comprehensive approach for the physical examination of the cervical spine, scapula, and rotator cuff is presented and descriptions on how the tests are performed and the evidence behind why specific tests are used in enabling improved diagnosis of shoulder pathology are discussed.

A Correlation Study of Clinical Outcomes by Quantification of Fatty Degeneration of the Subscapularis: Partial vs. Whole Cross-section

Background

Fatty degeneration of rotator cuff is a well-known predictor of postoperative outcome. The purpose of this study was to evaluate the clinical features of rotator cuff tears involving subscapularis, and investigate whether fatty degeneration quantified from only the upper subscapularis correlates better with clinical outcomes than quantified from the whole subscapularis.

Methods

We retrospectively analyzed 315 consecutive patients who underwent arthroscopic repair for rotator cuff tears involving subscapularis with a minimum follow-up of 1 year. Preoperative and postoperative visual analogue score for pain, range of motion and functional scores were assessed. Integrity of the repaired tendon was assessed at the 1-year follow-up with either magnetic resonance imaging or ultrasonography.

Results

The mean Goutallier grade of whole cross-section was significantly lower than that of upper cross-section (1.59 vs. 1.71, p<0.05), but significantly higher than that of lower cross-section (1.59 vs. 1.01, p<0.05). In analysis of 37 re-tears, the occupancy of severe fatty degeneration in upper cross-section was 86.5%, which was significantly higher than that seen in whole cross-section (56.8%, p<0.05). We calculated the cut-off tear size for prediction of re-tears as 19.0 mm for retraction and 11.0 mm for superior-inferior. The cut-off Goutallier grade was 2.5 for both whole and upper cross-sections, but area under the curve was greater in the upper cross-section than the whole (0.911 vs. 0.807).

Conclusions

As fatty degeneration of upper subscapularis demonstrated a more distinct spectrum than whole subscapularis, we suggest that measuring fatty degeneration of upper subscapularis can be a more useful method to predict clinical prognosis.

Diagnostic performance of clinical tests for subscapularis tendon tears

PURPOSE

Tears of the subscapularis (SSC) tendon constitute a diagnostic challenge. The purpose of the present study was to evaluate the diagnostic capabilities of five clinical SSC tests.

METHODS

Five established clinical tests were evaluated in 106 consecutive patients prior to shoulder arthroscopy. The tests included the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test. The integrity of the SSC tendon at surgery was used as the gold standard. Lesions to the SSC were graded according to Fox and Romeo.

RESULTS

There were 32 SSC lesions accounting for an incidence of 30.2%. The sensitivity for all tests was 0.66, while the specificity was 0.82. For all tests, positive tests results were found to be dependent on subscapularis integrity (p < 0.001, respectively). The sensitivity for any type of SSC lesion for the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test was 0.35, 0.41, 0.34, 0.31, and 0.52, respectively. Specificity was found to be 0.98, 0.91, 0.96, 0.97, and 0.85, respectively. If only grade 2-4 tears were analysed, sensitivity was 0.32, 0.42, 0.37, 0.37, and 0.72 and specificity 0.94, 0.86, 0.92, 0.94, and 0.84. A positive correlation was found between the number of positive tests and the severity of the SSC lesions.

CONCLUSION

In the present study, the Bear Hug Test was found to have the highest sensitivity of all tests studied, especially for tears of the upper tendon border. It appears advisable to perform more than one clinical subscapularis test to further improve sensitivity. Nevertheless, SSC tears may still escape clinical recognition. Therefore, a high index of suspicion has to be maintained in order not to miss SSC tears.

LEVEL OF EVIDENCE

Diagnostic study, Level I.

Physical therapists as first-line diagnosticians for traumatic acute rotator cuff tears: a prospective study

BACKGROUND

Early diagnosis of traumatic acute full-thickness rotator cuff tears (FTRCT) is important to offer early surgical repair. Late repairs following fatty infiltration of the rotator cuff muscles have less favorable results. We think that physical therapists are valuable diagnosticians in a screening process. The objective of this study was to evaluate the usefulness of physical therapists as first-line diagnosticians in detecting acute traumatic FTRCT.

METHODS

Between November 2010 and January 2014, 394 consecutive patients having an age between 18 and 75 years who sought medical care because of acute shoulder trauma with acute onset of pain, limited abduction and negative plain radiographs were included in the study. A clinical assessment was conducted by a physical therapist 1 week after the trauma. The patients were divided into three groups by the physical therapist according to the findings: FTRCT (Group I, n = 122); sprain (Group II, n = 62); or other specific diagnoses (Group III, n = 210). Group III patients were discharged and excluded from the study. Magnetic Resonance Imaging shoulder was performed for all Group I patients and for all patients with persistent symptoms in Group II.

RESULTS

79/184 patients had FTRCTs documented by MRI in groups I and II. The clinical assessment of the physical therapist had a sensitivity of 85%, specificity of 68%, and usefulness index of 0.45 (> 0.35 considered useful) for diagnosing FTRCT.

CONCLUSION

Physical therapists can be useful as first-line diagnosticians in detecting traumatic FTRCT.

Diagnostic Value of the Supine Napoleon Test for Subscapularis Tendon Lesions

PURPOSE

The purpose of this study was to compare the diagnostic value of the supine Napoleon test (a variation of the belly-press test that reduces compensatory motion) with other clinical tests for subscapularis tendon (SSC) tears.

METHODS

One hundred thirty consecutive patients who were scheduled for arthroscopic rotator cuff repair were evaluated preoperatively with the lift-off test, Napoleon test, bear-hug test, and supine Napoleon test. The supine Napoleon test was performed by placing the patient's hand on their belly while they lay supine with an examiner holding their hand and shoulder to prevent compensatory motion. The patient was asked to move their elbow upward and the test was considered positive if they were unable to do so. During surgery, SSC lesions were classified with the Lafosse classification system. Sensitivity, specificity, accuracy, and positive and negative likelihood ratios (LR+, LR-) were calculated for each test. The ability to detect partial SSC tears was compared among the clinical tests.

RESULTS

Fifty-two of 130 patients (40%) had SSC tears confirmed arthroscopically. For diagnosis of these tears, the supine Napoleon test was the most sensitive (84%), followed by the bear-hug test (74%), and the bear-hug test was the most specific (97%), followed by the supine Napoleon test (96%). The LR+ was greatest for the bear-hug test (28.4) and next greatest for the supine Napoleon test (21.9). The LR- was lowest for the supine Napoleon test (0.16) and the bear-hug test was second (0.27). The sensitivity of the supine Napoleon test (65%) was highest for detecting partial tears.

CONCLUSIONS

In comparison with other clinical tests for SSC tears, the supine Napoleon test had the greatest diagnostic value for full-thickness SSC tears and was most able to detect partial tears.

LEVEL OF EVIDENCE

Level III, diagnostic nonrandomized study.

Multi-modal imaging of the subscapularis muscle

Abstract

The subscapularis (SSC) muscle is the most powerful of the rotator cuff muscles, and plays an important role in shoulder motion and stabilization. SSC tendon tear is quite uncommon, compared to the supraspinatus (SSP) tendon, and, most of the time, part of a large rupture of the rotator cuff. Various complementary imaging techniques can be used to obtain an accurate diagnosis of SSC tendon lesions, as well as their extension and muscular impact. Pre-operative diagnosis by imaging is a key issue, since a lesion of the SSC tendon impacts on treatment, surgical approach, and post-operative functional prognosis of rotator cuff injuries. Radiologists should be aware of the SSC anatomy, variability in radiological presentation of muscle or tendon injury, and particular mechanisms that may lead to a SSC injury, such as coracoid impingement.

Teaching Points

• Isolated subscapularis (SSC) tendon tears are uncommon.

• Classically, partial thickness SSC tendon tears start superomedially and progress inferolaterally.

• Long head of biceps tendon medial dislocation can indirectly signify SSC tendon tears.

• SSC tendon injury is associated with anterior shoulder instability.

• Dynamic ultrasound study of the SSC helps to diagnose coracoid impingement.

Repair versus shaving of partial-thickness articular-sided tears of the upper subscapularis tendon. A prospective randomized controlled trial

PURPOSE

the purpose of this study was to evaluate whether treating partial-thickness articular-sided tears of the upper subscapularis (SSC) tendon with a dedicated suture anchor would result in an internal rotation strength improvement compared with simple shaving of the SSC tendon and footprint.

METHODS

twenty-six patients with a limited SSC tendon tear (equal or inferior to the most superior centimeter) in association with a posterosuperior cuff lesion were prospectively randomized to two treatments: repair with a dedicated suture anchor versus shaving of the tendon and footprint. The patients also underwent long head of the biceps (LHB) treatment and posterosuperior cuff tear repair. In each patient the following parameters were measured both preoperatively and at a minimum follow-up of 2.5 years: strength in internal rotation in the bear-hug testing position (using a digital tensiometer), DASH score and Constant scores. MRI assessment of tendon healing was performed at the final follow-up.

RESULTS

twenty of the 26 patients (76%) were reviewed after a mean follow-up time of 42 months: 11 patients had undergone SSC tendon repair and nine simple shaving. At final follow-up no significant differences were found between the repaired and shaving group in strength in internal rotation (9.5 ± 3.8 kg versus 10.3±5.4 kg; p=0.7). The DASH score and Constant score also failed to show significant differences between the two groups. Furthermore, no significant difference in SSC tendon healing rate was observed on MRI evaluation.

CONCLUSIONS

partial-thickness articular-sided tear of the upper SSC tendon in association with a posterosuperior rotator cuff repair and LHB treatment, when limited to the superior centimeter of the SSC tendon, shows a comparable performance in terms of strength in internal rotation either after simple shaving or a tendon-to-bone repair.

LEVEL OF EVIDENCE

Level II, prospective comparative study.