Sentinel sign: a sign of biceps tendon which indicates the presence of subscapularis tendon rupture

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 increasingly recognized as a 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 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.

Factors associated with long head of the biceps tendon tear severity and predictive insights for grade II tears in rotator cuff surgery

BACKGROUND

In rotator cuff repair, the long head of the biceps tendon (LHB) is commonly used as graft material. However, factors influencing LHB tear severity are poorly understood, and predicting grade II LHB tears is challenging. This study aimed to identify these factors preoperatively.

METHODS

The demographics, medical parameters, and pain severity of 750 patients who underwent arthroscopic surgery from January 2010 to February 2021 were evaluated to determine the factors associated with LHB tear severity and grade II tears. Both overall and largeto-massive rotator cuff tear (RCT) cohorts underwent ordinal and binary logistic regression analyses. Predictive accuracy for grade II LHB tears was determined using the area under the receiver operating characteristic curve (AUC).

RESULTS

In the overall cohort, high-sensitivity C-reactive protein (hs-CRP) >1 mg/L (P<0.001), subscapularis tear (P<0.001), hypothyroidism (P=0.031), and the tangent sign (P=0.003) were significantly associated with LHB tear severity, and hs-CRP>1 mg/L, subscapularis tear, and Patte retraction degree were significantly associated with grade II LHB tears (P<0.001). In the large-to-massive RCT cohort, hs-CRP>1 mg/L, hypertension, and age ≥50 years (P<0.05) were significantly associated with LHB tear severity, and hs-CRP>1 mg/L (P<0.001) and hypertension (P=0.026) were significantly associated with grade II LHB tears. In both cohorts, hs-CRP >1 mg/L demonstrated good predictive accuracy for grade II LHB tears (AUCs: 0.72 and 0.70).

CONCLUSIONS

Serum hs-CRP >1 mg/L is associated with LHB tear severity and serves as a reliable predictor of grade II LHB tears, facilitating preoperative assessment of the LHB as potential graft material in arthroscopic rotator cuff repair. Level of evidence: III.

Editorial Commentary: Artificial Intelligence Models Using Machine Learning Can Improve Preoperative Identification of Subscapularis Pathology

Subscapularis pathology is difficult to diagnose, in part because of decreased sensitivity and accuracy in identifying tears with magnetic resonance imaging (MRI) when compared to other cuff tendons. Artificial intelligence evaluation of patient physical examination and MRI data using a machine learning model shows that arthroscopically confirmed partial- or full-thickness subscapularis tears are highly associated with abnormal subscapularis tendon length, long head of the biceps tears, and subscapularis fatty atrophy, and on physical examination, with weakness with internal rotation and positive lift-off, belly press, and bear hug tests. Today, physicians may use machine learning as a tool, but this model may not currently be sufficient to drastically change practice. However, with continued research and development, which is occurring rapidly, similar models could aid physicians in timely identification of pathology and optimization of preoperative planning, as well as physician training and education.

The long head of biceps at the shoulder: a scoping review

BACKGROUND

This review aimed to explore the available literature to update our understanding of the long head of biceps (LHB) at the shoulder. Synthesise our findings to identify emergent themes and knowledge gaps to inform future research and management directions.

METHODS

PubMed, Embase, Cinahl, SportDiscus, CENTRAL, and Web of Science were searched from inception to 31st December 2021. Articles were included if they referenced adult participants > 18 years of age and were written in English.

RESULTS

214 articles were included in the final analysis, and results were categorised into six emergent themes: (1) Anatomy - Normal anatomical variation of the biceps from aberrant origins, third and fourth accessory heads, and an absence of the LHB tendon (LHBT) are not necessarily benign, with shoulder pain and instability a commonly reported theme. (2) Function - Bicep's role in glenohumeral elevation and stability in healthy shoulders is minimal. In contrast, LHB has a more significant role in shoulder stability and humeral head depression in subjects with rotator cuff failure or an absent LHBT. (3) Pathology - There is an association between LHB tendinopathy, rotator cuff disease, LHBT instability and occult rotator cuff tears. Early recruitment and hyperactivity of the LHB in subjects with symptomatic rotator cuff tears and instability suggest a potential compensatory role. (4) Assessment - The limited diagnostic utility of special orthopaedic tests in assessing LHBT pathology was a consistent theme. The utility of magnetic resonance imaging and ultrasound to identify full-thickness tendon tears and instability of the LHBT was moderate to high. However, the utility of clinical tests and imaging may be underestimated due to arthroscopy's limitations in fully visualising the proximal LHBT. (5) Non-Surgical Management - Ultrasound-guided injections into the biceps sheath show greater accuracy and patient outcomes than blinded injections; however, the entry of injectate into the intraarticular glenohumeral joint may have unwanted complications. (6) Surgical management - For the surgical management of biceps pathology with or without rotator cuff pathology, both biceps tenodesis and tenotomy report similar improvements in pain without any significant adverse effect on strength or function. Tenodesis favoured higher overall constant scores and a lower incidence of Popeye deformity and cramping arm pain, with tenotomy trending to be more cost and time effective. For patients with a healthy LHBT, rotator cuff repair with adjunctive tenodesis or tenotomy fails to provide additional clinical improvements compared to rotator cuff repair in isolation.

CONCLUSIONS

The scoping review highlights the variability of biceps anatomy, which is not necessarily benign and suggests a minimal role of the LHB in shoulder elevation and stability in healthy individuals. In contrast, individuals with rotator cuff tears experience proximal humeral migration and demonstrate hyperactivity of the LHB, suggesting a potential compensation role. The observed prevalence of LHBT pathology with rotator cuff tears is well established; however, the cause-and-effect relationship between LHBT pathology and rotator cuff disease is undetermined. The diagnostic utility of clinical tests and imaging to exclude LHBT pathology may be understated due to the limitations of arthroscopy to visualise the proximal LHBT fully. Rehabilitation programs for the LHB are understudied. Similar post-surgical clinical outcomes are observed for tenodesis and tenotomy for biceps and rotator cuff-related shoulder pain. Subjects undergoing biceps tenodesis are less likely to have cramping arm pain and a Popeye deformity than patients undergoing biceps tenotomy. The significance of routine surgical removal of the LHBT and sequelae on rotator cuff tear progression to failure and long-term shoulder function is unknown, and further research is required.

PRE-REGISTRATION

OSF: https://osf.io/erh9m.

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.

Subscapularis tendon tears hidden by the medial biceps sling can be missed on arthroscopic examination

INTRODUCTION

To investigate (1) the prevalence of "hidden lesions" and "non-hidden lesions" of subscapularis tendon tears requiring repair during arthroscopic examination that would be missed by a 30° arthroscope, but could be identified by a 70° arthroscope, from the standard posterior portal and (2) the correlation of preoperative internal rotation weakness and findings of magnetic resonance imaging (MRI) indicating hidden lesions.

MATERIALS AND METHODS

We retrospectively examined 430 patients who underwent arthroscopic subscapularis repair between was initially nonvisible with a 30° arthroscope but became visible only with a 70° arthroscope from the standard posterior portal. The preoperative and intraoperative findings of the hidden lesion group (n = 82) were compared with those of the non-hidden lesion group (n = 348). 2016 and 2020. A hidden lesion was defined as a subscapularis tendon tear requiring repair that preoperative internal rotation weakness was assessed using the modified belly-press test. Preoperative MR images were reviewed using a systemic approach.

RESULTS

The prevalence of hidden lesions was 19.1% (82/430). No significant difference was found in preoperative internal rotation weakness between the groups. Preoperative MRI showed a significantly lower detection rate in the hidden lesion group than in the non-hidden group (69.5% vs. 84.8%; P = 0.001). The hidden lesions were at a significantly earlier stage of subscapularis tendon tears than the non-hidden lesions, as revealed by the arthroscopic findings (Lafosse classification, degree of retraction; P = 0.003 for both) and MR findings (muscle atrophy, fatty infiltration; P = 0.001, P = 0.005, respectively).

CONCLUSIONS

Among the subscapularis tears requiring repair, 19.1% could be identified by a 70° arthroscope, but not by a 30° arthroscope, through the posterior portal. The hidden lesions showed a significantly lower detection rate on preoperative MRI than the non-hidden lesions. Thus, for subscapularis tears suspected on preoperative physical examination, the 70° arthroscope would be helpful to avoid a misdiagnosis.

[Anatomy and diagnostics of subscapularis tendon lesions]

Among lesions of the rotator cuff, subscapularis tendon tears are one of the less common injuries and mostly occur in combination with additional lesions of the posterosuperior rotator cuff and the long biceps tendon. If a subscapularis tendon rupture is suspected in the initial clinical testing, the primary diagnostics should include modern cross-sectional magnetic resonance imaging to assess the tendon lesion and to detect concomitant pathologies. Nevertheless, subscapularis tendon lesions are often initially overlooked and first correctly diagnosed during shoulder arthroscopy.

Current concepts review in the management of subscapularis tears

Subscapularis (SSc) is the prime internal rotator of shoulder. It is the most powerful rotator cuff muscle, maintaining the anterior force couple of shoulder. The tears in SSc as any other rotator cuff muscles might result from a traumatic event or more commonly from intrinsic degeneration. With the advent and widespread use of shoulder arthroscopy, SSc tears, which were once considered as "forgotten or hidden lesions" are now being increasingly recognized. Isolated SSc tears are relatively rare. They occur in combinations. Clinically internal rotation can be near normal because of the compensation provided by other internal rotators. It is not uncommon for patients with SSc tear to be normal on routine physical examination. The Bear Hug test (BHT) has high sensitivity and accuracy in the diagnosis of SSc tear. The combined use of BHT with Belly Press Test has been found optimal for diagnosis. US is an accurate and reliable method for diagnosing SSc tears and outperformed MRI in diagnosing partial-thickness SSc tears. The MRI is currently the most advanced imaging available for diagnosis. The specificity is up to 100%. However, the sensitivity is between 36 and 40%. The earliest classification system for SSc tears was by Fox et al. The commonly used classification is by Lafosse et al. The recent system by Yoo et al. is based on the insertion of SSc. The comma sign is gaining importance not only in arthroscopic diagnosis but also in MRI identification and repair of SSc. The mode of management is mainly arthroscopic. The techniques of repair of SSc are continuously progressing. However, there is no clear consensus on the double vs single-row repairs, biceps tendon management, and the role of coracoplasty. Future research must focus on these areas. Reserve shoulder arthroplasty is reserved for salvage in older age groups. Tendon transfers are performed in young active individuals with irreparable tears.

The IBTIS score; a new prognostic score for arthroscopic biceps tenotomies

INTRODUCTION

Shoulder pain associated with tendinopathy of the long head of biceps (LHB) is common. Surgical treatment with arthroscopic tenotomy of the LHB has been shown to be effective. However, it's efficacy is inconsistent. The objective of this study was to assess the pre-operative clinical and radiological prognostic factors of arthroscopic tenotomy of the long head of biceps, and to establish a predictive score for good responses to treatment; the IBTIS score (Isolated Biceps Tenotomy Index Score).

HYPOTHESIS

Prognostic factors representing a good response to treatment of LHB tendinopathy by arthroscopic tenotomy exist.

MATERIALS AND METHODS

We conducted a retrospective monocentric study including 64 patients who underwent surgery of the LHB by arthroscopic tenotomy (with or without tenodesis) between January 2018 and March 2020. We identified 2 patient groups (good responder group and poor responder group) from a 3-month post-operative clinical assessment, which included a subjective assessment comprising Single Shoulder Value (SSV), Constant score, C-Test, and pain level. Prognostic factors of a good response were then sought from the 2 groups using interviews, clinical examinations and pre-operative imaging. Based on these findings, a predictive score for a good response was established.

RESULTS

All evaluation criteria demonstrated post-operative improvement: mean SSV (72.2 vs 50.7; p<0.001), relative constant (78.2 vs 64.3; p<0.001), pain level (3.2 vs 7; p<0.001) and C-Test (94.1 vs 85.6; p=0.07). 34 patients (58.6%) were considered good responders, while 24 patients (41.38%) were considered poor responders. There was a trend towards a favourable result for: age>65 years (p=0.01), rotator cuff rupture on preoperative imaging (p=0.01), Cross Arm Test (p=0.02), nocturnal pain (p=0.08), Yergason's test (p=0.16) and Speed's Test (p=0.22). Manual labour appeared to be an unfavourable factor (p=0.07). These factors were incorporated into the 10-point IBTIS score. A score greater than 5 was associated with a favourable result in more than 80% of patients (p<0.001).

DISCUSSION

Our score consists of 7 items. We identified 7 pre-operative prognostic factors for a good result after LHB tenotomy. Over 65 years of age was found to be statistically significant in univariate analysis, as was visualization of rotator cuff rupture on pre-operative imaging. The Cross Arm Test was included given its high statistical significance. The Speed's Test and Yergason's Test are ubiquitous in the literature. Nocturnal pain was found in more than 80% of patients. Undertaking manual labour represented an unfavourable prognostic factor after arthroscopic surgery of the LHB.

CONCLUSION

The IBTIS score (Isolated Biceps Tenotomy Index Score) is a pre-operative clinico-radiological score for the surgical treatment of arthroscopic tenotomy of the long head of biceps. Further studies are required to validate its prognostic accuracy.

LEVEL OF EVIDENCE

III; case-control.

Single-Portal Proximal Biceps Tenodesis Using an All-Suture Anchor

The long head of the biceps is an important pain generator of the shoulder joint. Pathologies of the long head of the biceps involve superior labrum anterior to posterior lesions, pulley lesions, partial tears of the biceps tendon, biceps tendonitis, and medial biceps subluxation caused by full-thickness subscapularis tendon tears. Treatment of an inflamed or injured long head of the biceps by either tenotomy or tenodesis is often mandatory during shoulder arthroscopy to avoid persisting pain and possible revision procedures. In comparison with a tenotomy of the biceps tendon, a biceps tenodesis preserves the tension, anatomy, and cosmesis of the biceps muscle. The presented technique demonstrates a single portal technique for a proximal biceps tenodesis in the bicipital groove using an all-suture anchor.

Comparison of Knotless and Knotted Single-Anchor Repair for Ruptures of the Upper Subscapularis Tendon: Outcomes at 2-Year Follow-up

Background:

Both knotted and knotless single-anchor repair techniques are used to repair transmural ruptures of the upper subscapularis (SSC) tendon. However, it is still unclear which technique provides better clinical and radiological results.

Purpose/Hypothesis:

To compare the clinical and magnetic resonance imaging (MRI) outcomes of knotless and knotted single-anchor repair techniques in patients with a transmural rupture of the upper SSC tendon at 2-year follow-up. It was hypothesized that the 2 techniques would not differ significantly in outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Forty patients with a transmural tear of the upper SSC tendon (grade 2 or 3 according to Fox and Romeo) were retrospectively enrolled. Depending on the repair technique, patients were assigned to either the knotless single-anchor or knotted single-anchor group. After a mean follow-up of 2.33 ± 0.43 years, patients were assessed by the ASES, WORC, OSS, CS, and SSV. A clinical examination that included the bear-hug, the lift-off, and the belly-press tests was performed, in which the force exerted by the subjects was measured. In addition, all patients underwent MRI of the affected shoulder to assess repair integrity, tendon width, fatty infiltration, signal-to-signal ratio of the upper and lower SSC muscle, and atrophy of the SSC muscle.

Results:

No significant difference was found between the 2 groups on any of the clinical scores [ASES (P = .272), WORC (P = .523), OSS (P = .401), CS (P = .328), SSV (P = .540)] or on the range-of-motion or force measurements. Apart from a higher signal-to-signal ratio of the lower SSC muscle in the knotless group (P = .017), no significant difference on imaging outcomes was found between the 2 groups.

Conclusion:

Both techniques can be used in surgical practice, as neither was found to be superior to the other in terms of clinical or imaging outcomes at 2-year follow-up.

Ultrasonography Outperforms Magnetic Resonance Imaging in Diagnosing Partial-Thickness Subscapularis Tear

PURPOSE

To evaluate the diagnostic reliability of ultrasonography (US) and magnetic resonance imaging (MRI) for subscapularis (SSC) tears with shoulder arthroscopy as the gold standard and to investigate the diagnostic value of 2 MRI signs (lesser tuberosity cysts and subcoracoid cysts) for SSC tears.

METHODS

We consecutively enrolled 437 patients who were scheduled to undergo arthroscopic rotator cuff repair from January 2019 to December 2020. Patients with previous shoulder surgery or shoulder fracture, recurrent shoulder instability, and systemic inflammatory disease were excluded. Preoperative US and MRI of the shoulder were performed and interpreted with a standardized approach. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of US and MRI were calculated using arthroscopic findings as the gold standard.

RESULTS

Of the 437 patients, 157 had SSC tears confirmed at the time of arthroscopy, 126 of whom had partial-thickness tears. US correctly diagnosed 122 of 157 patients with SSC tears, with an overall sensitivity of 77.7% (confidence interval [CI] 70.6%-83.5%), which was significantly greater than that of MRI (49.7%, CI 42.0%-57.4%, P < .001). For partial-thickness SSC tears, US correctly diagnosed 93 of 126 positive patients and 276 of 311 negative patients. This resulted in a sensitivity of 73.8% (CI 65.5%-80.7%), specificity of 88.7% (CI 84.8%-91.8%), and accuracy of 84.4% (CI 80.7%-87.5%). As with MRI, the sensitivity, specificity, and accuracy were 38.1% (CI 29.7%-47.2%), 86.5% (CI 82.3%-89.9%), and 72.5% (CI 68.2%-76.5%), respectively. Lesser tuberosity cysts and subcoracoid cysts were 2 MRI signs with high specificity (98.2% and 94.6%); however, their sensitivities were relatively low (19.8% and 33.8%).

CONCLUSIONS

US is a reliable and accurate diagnostic method for SSC tears, especially in easily missed partial-thickness tears. Lesser tuberosity cyst and subcoracoid cyst are highly specific but insensitive MRI signs for SSC tear.

LEVEL OF EVIDENCE

Level I, diagnostic, testing of previously developed diagnostic criteria.

Arthroscopic diagnosis of long head of biceps tendon instability in refractory anterior shoulder pain: A comparison study between pulley tear and non-tear lesions

BACKGROUND

Long head of the biceps tendon (LHBT) instability and biceps reflection pulley (BRP) lesions are common cause of refractory anterior shoulder pain. We described a technique using dynamic arthroscopy to determine associated intraarticular pathologies.

METHODS

Patients with refractory anterior shoulder pain and arthroscopically-diagnosed LHBT instability were enrolled. LHBT instability and the integrity of BRP and concomitant intra-articular lesions were investigated by ramp test. Demographics and arthroscopic findings were compared between patients with and without BRP tear.

RESULTS

Forty patients were enrolled. BRP tear was noted in 25 patients (group A) and superior glenohumeral ligament (SGHL) insufficiency through ramp test in 15 patients (group B). Concomitant intraarticular pathologies were noted in 27 patients, including 19 in group A (76%) and eight in group B (53%), without significant group-wise difference (p = 0.138). The incidence of articular-side subscapularis tear was significantly higher in group A (p = 0.021), and those of the other intraarticular pathologies were similar between groups A and B. Fraying at the articular side of the subscapularis and supraspinatus tendons was frequent in group B, without difference of incidence as compared to group A (p = 0.5 and p = 0.084, respectively).

CONCLUSIONS

LHBT instability was a common disorder in patients with refractory shoulder pain. In those patients, dynamic assessment of BRP lesions and SGHL insufficiency and meticulous survey of associated intra-articular pathologies, including subscapularis tear are necessary for making accurate diagnosis and treatment decision.

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.

Predicting the clinically significant subscapularis tendon tear: malposition and tear of the long head of the biceps tendon on shoulder magnetic resonance imaging

BACKGROUND

The diagnostic accuracy of magnetic resonance imaging (MRI) is low for detecting a subscapularis tendon tear.

PURPOSE

To identify MRI findings that may predict the presence of a clinically significant subscapularis tendon tear requiring surgical repair.

MATERIAL AND METHODS

We reviewed shoulder MR images of patients who had undergone arthroscopic rotator cuff repair at our institution between June 2018 and May 2019. Patients were divided into two groups: the study group (n = 51), with an intermediate- to high-grade partial thickness tear of the subscapularis tendon suspected on preoperative MRI and intermediate or higher grade of the tendon tear proven on arthroscopy; and the control group (n = 18), with an intermediate- to high-grade partial thickness tear of the subscapularis tendon suspected on preoperative MRI but no tear or low-grade partial thickness tear of the tendon shown on arthroscopy. Preoperative MR images were retrospectively evaluated by two readers for the size of the subscapularis tendon tear, bone reactions at the lesser tuberosity, and long head of the biceps tendon (LHBT) pathology.

RESULTS

The subscapularis tendon tear measured by reader 2 was larger in the study group than in the control group. The prevalence of a tear (P = 0.006 for reader 1; P = 0.011 for reader 2) and malposition (P < 0.001 for both readers) of the LHBT were significantly greater in the study group.

CONCLUSION

A tear and malposition of the LHBT on MR images may predict the presence of a clinically significant subscapularis tendon tear.

Arthroscopic Revision Rotator Cuff Repair: The Role of Previously Neglected Subscapularis Tears

BACKGROUND

Concomitant full-thickness tear of the subscapularis tendon is often neglected during primary posterosuperior rotator cuff repair, and its significance has not been investigated by any previous clinical study.

PURPOSE

To investigate (1) the clinical and radiological outcomes of revision arthroscopic rotator cuff repair and (2) the number of neglected concomitant subscapularis full-thickness tears in the revision of posterosuperior rotator cuff retears and their structural integrity after repair.

STUDY DESIGN

Case series, Level of evidence, 4.

METHODS

This study retrospectively examined 58 patients who underwent arthroscopic rotator cuff revision for a retear of a previously repaired posterosuperior rotator cuff. Preoperative and postoperative functional scores and active range of motion (ROM) were assessed. The initial and most recent follow-up magnetic resonance imaging scans before revision and arthroscopic findings at the time of primary repair were reviewed to determine whether the concomitant subscapularis tear was newly developed or preexisting. Final confirmation of the tendon's full-thickness tear was made during the revision procedure.

RESULTS

At final follow-up, mean functional shoulder scores and ROM improved significantly compared with the preoperative values (P < .001). Among the 58 revision cases, 25 (43.1%) had a neglected full-thickness tear of the subscapularis tendon. The fatty infiltration grade of the neglected subscapularis tear progressed from a mean of 1.1 before primary repair to a mean of 1.6 before revision, and the change indicated statistically significant deterioration (P < .001). Despite clinical improvement after revision surgery, the retear rate was considerable in the re-repaired cuff tendons (37.9%) as well as for the repaired concomitant subscapularis tears (24%).

CONCLUSION

Among revision rotator cuff repairs, 43.1% had neglected subscapularis tears, and fatty infiltration of these initially neglected subscapularis tendons showed further progression at the time of revision. The retear rate after the repair of neglected subscapularis tears was higher than expected. Thus, detecting and treating subscapularis tear via meticulous preoperative evaluation and thorough inspection during primary arthroscopy are essential.

Subcapularis tendon tear: A structure-based arthroscopic description

INTRODUCTION

Subscapularis (SSC) tendons differ from supraspinatus tendons, although both have similar histologic structure comprising two layers with distinct collagen fiber organization.

HYPOTHESIS

The partial/full-thickness tear classification for the supraspinatus based on tendon structure can be applied to the subscapularis tendon on objective criteria.

MATERIAL AND METHODS

The present study used 100 films of arthroscopic rotator cuff repair involving SSC lesion. Lesions were reported on 3 objective criteria: horizontal superior tendon edge visibility, lesser tuberosity bone exposure, and lateral tendon edge visibility. Combining the three distinguishes deep, superficial or interstitial partial tear versus full-thickness tear. Degree of retraction was also noted.

RESULTS

Forty-six of the 73 partial lesions involved the deep articular layer, which was often retracted, but conserving the horizontal superior tendon edge and thus misleadingly suggesting SSC integrity; 23 were interstitial, without detachment from the lesser tuberosity; 4 involved only the superficial layer. Full-thickness tears were always retracted, with loss of horizontal superior tendon edge, visibility of the lateral tendon edge and presence of comma sign. Inter- and intra-observer reproducibility was satisfactory.

DISCUSSION - CONCLUSION

Like in superior cuff tear, a structure-based classification can be made of SSC lesions on objective criteria.

LEVEL OF EVIDENCE

IV.

Hidden Long Head of the Biceps Tendon Instability and Concealed Intratendinous Subscapularis Tears

Background:

Few studies have described the characteristics of a concealed intratendinous subscapularis tear (CIST), and there is a lack of research on the preoperative predictability of such lesions.

Purpose:

To describe the characteristics of a CIST as seen on magnetic resonance imaging (MRI) and intraoperatively and to develop a scoring system for predicting such lesions.

Study Design:

Case series; Level of evidence, 4.

Methods:

Retrospectively, we identified 43 patients with CISTs among 442 consecutive patients who had undergone rotator cuff repair from July 2014 to June 2016. Range of motion, visual analog scale results for pain and function, and patient-reported outcome scores were evaluated preoperatively and at 1 and 2 years postoperatively. CISTs were classified arthroscopically as small (<5 mm), medium (5-10 mm), and large (>10 mm). We performed repair (≥50%) or debridement (<50%) depending on the total subscapularis tendon tear size including the CIST. Preoperative MRI findings were analyzed by 2 observers and were correlated with the arthroscopic findings. A 10-point scoring system was developed based on characteristics during the physical examination (anterior tenderness, bear hug sign), MRI (biceps tendon displacement and subluxation, subscapularis signal change just lateral to the lesser tuberosity), and arthroscopic surgery (medial biceps tendon lesion, combined subscapularis tendon tear), with a cutoff value of ≥7 predicting a CIST. After the retrospective study, we prospectively enrolled 95 patients to validate the 10-point CIST scoring system.

Results:

All 43 patients diagnosed with a CIST during the retrospective study improved both range of motion and functional scores at 1 year postoperatively. The interrater agreement of the 2 observers was substantial for the evaluation of all parameters except for subscapularis tear classification, which was moderate. On arthroscopic surgery, 11 small, 19 medium, and 13 large CISTs were detected. The preliminary prospective study showed a sensitivity of 61.9%, specificity of 94.3%, positive predictive value of 89.0%, negative predictive value of 75.7%, and accuracy of 80.0% when the cutoff value was set at ≥7 on the CIST scoring system.

Conclusion:

A CIST can be suspected using a combination of preoperative MRI and intra-articular diagnostic arthroscopic findings, but a definitive diagnosis requires an arthroscopic view. On the 10-point CIST scoring system, a score of ≥5 can be suggestive of a CIST, and a score of ≥7 is most likely to predict a CIST.

The Invisible MGHL Test: Diagnostic Value and Benefits for the Repair of Retracted Subscapularis Tears

BACKGROUND

Some full-thickness subscapularis tendon tears and partial tears of the deep layer are difficult to characterize, leading to misdiagnosis.

PURPOSE

To evaluate the association between displacement of the middle glenohumeral ligament (MGHL) and retracted tears of the subscapularis tendon as a possible test to improve diagnosis.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Videos (N = 100) recorded during arthroscopic rotator cuff repair involving a torn subscapularis tendon were analyzed retrospectively to assess the association between the MGHL test (nonvisibility of the MGHL) and other objective anatomic criteria. The invisible MGHL test was defined as positive if the MGHL was initially nonvisible in the beach-chair position and appeared only when the subscapularis tendon was pulled back into position by using a 30° arthroscope from the standard posterior portal. The parameters considered during the initial exploration were (1) visibility of the horizontal part of the subscapularis tendon; (2) visibility of the MGHL in its usual position, crossing the superior border of the subscapularis tendon; (3) exposure of the lateral border of the subscapularis tendon (full-thickness retracted tear); and (4) complete or partial exposure of the lesser tuberosity of the humerus. Tendon retraction was evaluated in 3 stages according to the Patte classification.

RESULTS

The invisible MGHL test result was positive in 45% of cases. It was positive in 6% of cases (2 of 31) when there was no subscapularis tendon retraction and in 62% of cases (43 of 69) when there was partial or complete retraction (P < .001). The invisible MGHL test was significantly associated with the width of the tear (P < .001) and exposure of the lateral border of the subscapularis tendon (full-thickness retracted tear, P = .0002). After repair, the MGHL was visible in its anatomic position in 96% of cases.

CONCLUSION

A positive invisible MGHL test is an alternative indication of subscapularis tendon retraction, and the relocation of the MGHL can also be used after repair to assess the proper anatomic repositioning of the subscapularis tendon.

The Middle Glenohumeral Ligament Test for the Diagnosis of Subscapularis Lesions

Arthroscopy has improved the diagnosis of subscapularis tendon lesions, and the outcomes of arthroscopic repair are satisfactory. Nonetheless, the diagnosis of some partial- and full-thickness subscapularis tears remains challenging. The middle glenohumeral ligament inserts distally into the articular surface of the subscapularis tendon and can be displaced when the subscapularis tendon is torn with retraction. This article describes the middle glenohumeral ligament test, which allows retracted lesions of the subscapularis tendon to be detected even if the superior edge is visible and normally placed. In addition, it allows control of the subscapularis tendon repair.

Subscapularis tears: hidden and forgotten no more

The subscapularis tendon, at one point, was thought of as the forgotten tendon, with “hidden lesions” that referred to partial tears of this tendon. Better understanding of anatomy and biomechanics combined with improved imaging technology and the widespread use of arthroscopy has led to a higher rate of subscapularis tear diagnoses and repairs.

The bulk mass of the subscapularis muscle is more than that of all 3 other rotator cuff muscles combined. It functions as the internal rotator of the shoulder as the stout, rolled border of its tendon inserts onto the superior portion of the lesser tuberosity. A thorough history combined with specific physical examination maneuvers (including the bear hug, lift-off, and belly-press tests) is critical for accurate diagnosis. A systematic approach to advanced shoulder imaging also improves diagnostic capacity.

Once identified, most subscapularis tendon tears can be successfully repaired arthroscopically. The Lafosse classification is useful as part of a treatment algorithm. Type I and II tears may be addressed while viewing from the standard posterior glenohumeral portal; larger Lafosse type III and IV tears are best repaired with anterior visualization at the subacromial or subdeltoid space. Tendon mobilization for larger tears is critical for adequate repair.

In Lafosse type V tears, in which there is glenohumeral imbalance, tendon transfers and reverse replacement are commonly considered salvage options.

Arthroscopic Repair of Subscapularis Tendon Tears

The subscapularis is the largest and strongest muscle of the rotator cuff, and it plays an essential role in global shoulder function. Beyond its primary function as an internal rotator, the subscapularis also acts to pull the humeral head posteriorly on the glenoid and is an important dynamic and static anterior stabilizer of the glenohumeral joint. In comparison with tears of the tendons of the rest of the rotator cuff, isolated tears of the subscapularis have a tendency for both early retraction and fatty infiltration. Consequently, full-thickness tears of the subscapularis tendon generally require surgical management. Arthroscopic suture-anchor repair allows anatomic reconstruction of the anterior aspect of the rotator cuff, with all of the benefits of arthroscopic surgery. The principal steps of this procedure include (1) verifying the subscapularis tear and identifying any concomitant lesions during diagnostic arthroscopy, (2) exposing the subscapularis tendon, (3) releasing tendon adhesions and so enabling anatomic reduction, (4) placing suture anchors at the anatomic subscapularis footprint on the lesser tuberosity and anatomically repairing the subscapularis tendon to its anatomic insertion, and (5) performing biceps tenodesis or tenotomy, if indicated. Postoperatively, patients with an isolated subscapularis tear are managed with immobilization in a sling for 6 weeks, while those with combined anterosuperior rotator cuff tears are managed with an abduction pillow. Arthroscopic subscapularis reconstruction provides a good structural repair, substantially restores shoulder mobility and strength, reduces pain, and results in high levels of patient satisfaction and return of shoulder function as measured by functional outcome scores.

The Hidden Lesion of the Subscapularis: Arthroscopically Revisited

The "hidden lesion" refers to a tear of the subscapularis in the presence of an intact biceps pulley or rotator interval. Visualization of these tears during open surgery is difficult, yet even with the advancement of arthroscopy, visualization can still be challenging. Incomplete visualization of the subscapularis could lead to failure to diagnose a tear of the tendon and subsequently hinder results after shoulder surgery. With the advancement of arthroscopy, a technique to identify these hidden lesions is needed to avoid inferior results. We describe an arthroscopic technique to visualize, diagnosis, and repair these tears when clinically indicated. Implementing this technique in the setting of suspected subscapularis tendon injury can provide complete visualization of the tendon insertion.