Subscapularis tendon tears: Management and arthroscopic repair

Anatomical and surgical considerations of the pectoralis muscle

Introduction

The pectoralis major (PM) muscle is the largest and most superior muscle of the anterior chest wall. The PM plays an important role in flexion, adduction, and internal rotation of the arm. The pectoralis major's size, strength, and anatomical location make it an excellent candidate in transfer surgeries due to its ability to restore balancing forces that may be lost in scapular winging and subscapularis tears. Each of these injuries and pathologies involves the PM muscle in some way, and careful consideration of its anatomy and physiology is necessary. This review article aims to provide a comprehensive overview of the anatomy, physiology, and surgical considerations of the pectoralis muscle with a specific focus on the surgical techniques involving the muscle.

Methods

A comprehensive literature search using a combination of the following terms: pectoralis major, rupture, transfer, chronic subscapularis tear, pectoralis surgery, anatomy, scapular winging, and long thoracic nerve anatomy. There were no limitations with regards to article type or publishing date, but article language was limited to only English.

Conclusion

The pectoralis muscle is an important muscle when it comes to function of the upper extremity primarily or through transfer procedure. Injuries and impairments of the pectoralis major or other muscles of the upper extremity can significantly impact an individual's quality of life, limiting their ability to perform activities of daily living. A thorough understanding of anatomical, functional, and surgical purposes of the pectoralis muscle is crucial for achieving optimal outcomes and avoiding complications.

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.

A Machine Learning Model Demonstrates Excellent Performance in Predicting Subscapularis Tears Based on Pre-Operative Imaging Parameters Alone

PURPOSE

To develop a machine learning model capable of identifying subscapularis tears before surgery based on imaging and physical examination findings.

METHODS

Between 2010 and 2020, 202 consecutive shoulders underwent arthroscopic rotator cuff repair by a single surgeon. Patient demographics, physical examination findings (including range of motion, weakness with internal rotation, lift/push-off test, belly press test, and bear hug test), and imaging (including direct and indirect signs of tearing, biceps status, fatty atrophy, cystic changes, and other similar findings) were included for model creation.

RESULTS

Sixty percent of the shoulders had partial or full thickness tears of the subscapularis verified during surgery (83% of these were upper third). Using only preoperative imaging-related parameters, the XGBoost model demonstrated excellent performance at predicting subscapularis tears (c-statistic, 0.84; accuracy, 0.85; F1 score, 0.87). The top 5 features included direct signs related to the presence of tearing as evidenced on magnetic resonance imaging (MRI) (changes in tendon morphology and signal), as well as the quality of the MRI and biceps pathology.

CONCLUSIONS

In this study, machine learning was successful in predicting subscapularis tears by MRI alone in 85% of patients, and this accuracy did not decrease by isolating the model to the top features. The top five features included direct signs related to the presence of tearing as evidenced on MRI (changes in tendon morphology and signal), as well as the quality of the MRI and biceps pathology. Last, in advanced modeling, the addition of physical examination or patient characteristics did not make a significant difference in the predictive ability of this model.

LEVEL OF EVIDENCE

Level III, diagnostic case-control study.

Role of ultrasound and MRI in the evaluation of postoperative rotator cuff

Rotator cuff tears are common shoulder injuries in patients above 40 years of age, causing pain, disability, and reduced quality of life. Most recurrent rotator cuff tears happen within three months. Surgical repair is often necessary in patients with large or symptomatic tears to restore shoulder function and relieve symptoms. However, 25% of patients experience pain and dysfunction even after successful surgery. Imaging plays an essential role in evaluating patients with postoperative rotator cuff pain. The ultrasound and magnetic resonance imaging are the most commonly used imaging modalities for evaluating rotator cuff. The ultrasound is sometimes the preferred first-line imaging modality, given its easy availability, lower cost, ability to perform dynamic tendon evaluation, and reduced post-surgical artifacts compared to magnetic resonance imaging. It may also be superior in terms of earlier diagnosis of smaller re-tears. Magnetic resonance imaging is better for assessing the extent of larger tears and for detecting other complications of rotator cuff surgery, such as hardware failure and infection. However, postoperative imaging of the rotator cuff can be challenging due to the presence of hardware and variable appearance of the repaired tendon, which can be confused with a re-tear. This review aims to provide an overview of the current practice and findings of postoperative imaging of the rotator cuff using magnetic resonance imaging and ultrasound. We discuss the advantages and limitations of each modality and the normal and abnormal imaging appearance of repaired rotator cuff tendon.

Can subcoracoid effusion be a more specific finding for subscapularis tear among rotator cuff pathologies on magnetic resonance imaging?

HYPOTHESIS AND BACKGROUND

Magnetic resonance imaging (MRI) is a well-known, noninvasive diagnostic method for rotator cuff tendon pathologies that are not very sensitive for subscapularis tendon tears. Subcoracoid effusion (SE) is an easily recognizable radiologic sign on MRI. In this study, we aimed to examine the relationship of SE with rotator cuff tear and to investigate whether SE could be a supportive finding in the diagnosis of subscapularis tear in preoperative MRI. Our hypothesis was that SE was a more specific finding of subscapularis tear than other rotator cuff tears.

METHODS

The data of patients who underwent shoulder arthroscopy in our clinic between 2017 and 2021 were analyzed retrospectively. Four groups were included in the study: patients with a rotator cuff tear accompanied by a subscapularis tear (group 1, n = 273), patients with isolated subscapularis tear (group 2, n = 57), patients with rotator cuff tear with intact subscapularis tendon (group 3, n = 190), and patients without any rotator cuff pathology (group 4, n = 263). Arthroscopic video records and MRIs of all patients were evaluated retrospectively. Subscapularis tendon tears were classified according to the Lafosse classification.

RESULTS

There was a statistically significant difference between the groups in terms of the presence of SE on MRI (P = .001). The presence of SE in group 1 and group 2 was statistically significantly higher than that in both group 3 and group 4 (P = .001), and there was no significant difference between group 3 and group 4 (P > .05). A significant relationship was found between Lafosse classification and SE (P = .001). When the diagnostic powers of the detection of SSC tear and the presence of SE on MRI for SSC tear were compared, Kappa values were 0.615 (P = .001) and 0.701 (P = .001), and overall diagnostic accuracy rates were 80.3% and 85.5%, respectively.

CONCLUSION

We conclude that SE is a more specific finding for subscapularis tears than other rotator cuff pathologies. We suggest that SE on MRI should also be considered in patients with a rotator cuff tear in whom a subscapularis tear was not detected in preoperative MRI and that the subscapularis tendon should be carefully evaluated during surgery in cases where the effusion is positive.

Merged Lateral Row Modification of the Suture Bridge Technique for Simultaneous Supraspinatus and Subscapularis Repair

Concomitate supraspinatus and subscapularis tear is not rare, and the suture bridge technique is one of the most effective methods for rotator cuff repair. However, some limitations exist in the use of such a technique for simultaneous supraspinatus and subscapularis repair. We introduce the technique of a merged lateral row for suture bridge rotator cuff repair, in which the lateral suture of the supraspinatus and subscapularis is placed in the greater tuberosity. We believe that this technique can reduce both the duration and cost of surgery and decrease soft-tissue damage. It can also allow the "comma tissue," to be simultaneously repaired.

Arthroscopic Subscapularis Tendon Repair Using the Mason-Allen Technique

BACKGROUND

Arthroscopic rotator cuff repair has recently been popularized for treating tears. In a biomechanical trial, the Mason-Allen stitch improved the fixation quality of poorly vascularized tendons. The use of this technique involving the subscapularis tendon remains rare. The aim of this study was to evaluate the clinical outcomes of Mason-Allen technique repaired subscapularis tendons.

METHODS

A retrospective research of collected data from 98 patients with subscapularis tears who had undergone arthroscopic repair between May 2015 and December 2018. There were 75 males and 23 females. The mean age was 56.4 ± 9.6 years and the mean follow-up was 12.5 ± 4.0 months. The visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) score, and Constant-Murley score were used to analyze shoulder function. An MRI was performed to assess the integrity of the repair.

RESULTS

Patients had significantly less pain and a better active range of motion compared with preoperative levels. VAS improved significantly from a preoperative mean of 3.42 to a postoperative mean of 1.91. ASES increased significantly from the preoperative mean of 43.6 to the postoperative mean of 74.5. Seven cases suffered from retears, which were confirmed by an MRI examination.

CONCLUSION

Arthroscopic rotator cuff repair with the Mason-Allen method resulted in a decreased level of pain and satisfied function recovery.

Shoulder Injury Following Overzealous Manipulation in Adhesive Capsulitis by Untrained Professional Managed with Shoulder Arthroscopy

Introduction

Adhesive capsulitis of shoulder is a commoner condition in middle aged population and is classified into primary and secondary types based on etiology. Treatment options depend on stages of disease which ranges from physical therapy, non-steroidal anti-inflammatory medications, intra-articular steroid injection, hydro-dilatation therapy, manipulation under anesthesia, and arthroscopic capsular release. However, the condition is generally mismanaged by untrained professionals in the periphery center leading to complications. We report one such case, which was then managed arthroscopically.

Case Report

A 58-year-old female patient presented to our outpatient department with a severe painful left shoulder following overzealous manipulation by untrained professional and she was diagnosed with severe traumatic capsulosynovitis with a subscapularis tear, biceps tendon subluxation, and shoulder subluxation. We managed patient arthroscopically with extensive capsulosynovectomy, biceps tenotomy, and upper subscapularis repair. Postoperatively, she was immobilized for 6 weeks and was put on proper rehabilitation program. At the 2-year follow-up, the patient had an excellent outcome and had complete pain-free movements at the left shoulder with significant increase in pre-operative constant shoulder score of 12-82.

Conclusion

?Overzealous manipulation shoulder in frozen shoulder patients has serious complications and has to be avoided and therefore has to be done by trained professional gently under anesthesia. Shoulder arthroscopy plays a pivotal role in managing such complications successfully.

Association Between Medial Displacement of the Middle Glenohumeral Ligament and Subscapularis Tear Severity

Background:

The intraoperative invisible middle glenohumeral ligament (MGHL) test has been shown to be associated with a subscapularis tendon retraction. However, the preoperative location of the MGHL and its association with subscapularis tear severity has not been evaluated.

Purpose:

To determine (1) the interrater reliability for identification and position of the MGHL, (2) any association between the MGHL position and subscapularis tears, and (3) the cutoff point at which MGHL position can predict subscapularis tear severity.

Study Design:

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

Methods:

The magnetic resonance imaging (MRI) scans and surgical records of 176 patients were retrospectively reviewed by 3 independent orthopaedists. MGHL's identification, level (its position on axial MRI), and medial retraction ratio (distance from the lesser tuberosity to the MGHL divided by the width of the glenoid) were documented, and the interobserver agreement of the 3 indices was assessed. We calculated the association between subscapularis tears and the MGHL level and medial retraction ratio. Receiver operating characteristic (ROC) curve analyses were conducted to establish the optimal threshold of the MGHL medial retraction ratio to predict subscapularis tear.

Results:

The MGHL was identified by at least 2 reviewers in 124 individuals (70.5%). The interobserver reliability was very good for MGHL identification (κ = 0.766), moderate for MGHL level (κ = 0.582), and excellent for MGHL medial retraction ratio (intraclass correlation coefficient = 0.848). A low, positive correlation between MGHL level and subscapularis tear severity was found (Somers d = 0.392, P < .001), as well as a significant association between the medial retraction ratio and Lafosse classification of subscapularis tear size ( P < .001). A medial retraction ratio of ≥1.25 had a sensitivity of 0.70, a specificity of 0.83, and a positive likelihood ratio of 4.20, with excellent accuracy (area under the ROC curve = 0.820) to predict severe subscapularis tear.

Conclusion:

The MGHL was identified in 70.5% of shoulder MRIs. The location of the MGHL on preoperative MRI, as described by its level and the medial retraction ratio, was significantly associated with subscapularis tear severity, and a medial retraction ratio of ≥1.25 was predictive of a severe subscapularis tear.

Computational analysis of subscapularis tears and pectoralis major transfers on muscular activity

BACKGROUND

Pectoralis major is the most common muscle transfer procedure to restore joint function after subscapularis tears. Limited information is available on how the neuromuscular system adjusts to the new configuration, which could explain the mixed outcomes of the procedure. The purpose of this study is to assess how muscles activation patterns change after pectoralis major transfers and report their biomechanical implications.

METHODS

We compare how muscle activation change with subscapularis tears and after its treatment by pectoralis major transfers of the clavicular, sternal, or both these segments, during three activities of daily living and a computational musculoskeletal model of the shoulder.

FINDINGS

Our results indicate that subscapularis tears require a compensatory activation of the supraspinatus and is accompanied by a reduced co-contraction of the infraspinatus, both of which can be partially recovered after transfer. Furthermore, although the pectoralis major acts asynchronously to the subscapularis before the transfer, its activation pattern changes significantly after the transfer.

INTERPRETATION

The capability of a transferred muscle segment to activate similarly to the intact subscapularis is found to be dependent on the given motion. Differences in the activation patterns between intact subscapularis and the segments of pectoralis major may explain the difficulty in adapting psycho-motor patterns during the rehabilitation period. Thereby, rehabilitation programs could benefit from targeted training on specific motion and biofeedback programs. Finally, the condition of the anterior deltoid should be considered to improve joint function.

Preoperative Magnetic Resonance Imaging Accurately Detects the Arthroscopic Comma Sign in Subscapularis Tears

PURPOSE

To assess the accuracy and reliability of routine preoperative magnetic resonance imaging (MRI) in the detection of the comma sign compared with the gold standard of arthroscopic findings.

METHODS AND MATERIALS

Preoperative MRI exams in consecutive patients undergoing arthroscopic subscapularis tendon repair, over a 5-year time frame, were retrospectively reviewed for full-thickness tears of the subscapularis and supraspinatus tendons, fatty atrophy of the subscapularis and supraspinatus muscles, and status of the long head of the biceps tendon. Each case was also evaluated for presence or absence of a comma sign on MRI. Surgical findings served as the diagnostic standard of reference in determination of a comma sign.

RESULTS

The study cohort included 45 male and 10 female patients (mean age, 56; range, 32-80 years). A comma sign was present at arthroscopy in 19 patients (34.5%). Interclass and intrarater correlation showed 100% agreement in preoperative assessment of a comma sign on MRI. MRI showed an overall accuracy of 83.6% in diagnosis of a comma sign (sensitivity, 63.2%; specificity, 94.4%; positive predictive value, 85.7%; negative predictive value, 82.9%; positive likelihood ratio, 11.37; negative likelihood ratio, 0.39). No statistically significant association was observed between an arthroscopic comma sign and patient demographics or MRI findings of full-thickness rotator cuff tears, muscle fatty atrophy, or long head of the biceps tendon pathology.

CONCLUSIONS

MR imaging illustrates excellent reliability and good specificity and accuracy in detection of the arthroscopic comma sign in the setting of subscapularis tendon tearing. Detection of a comma sign on MRI may be important preoperative planning information in the arthroscopic management of patients with subscapularis tendon tears.

LEVEL OF EVIDENCE

Level IV, retrospective diagnostic study.

Single-Portal, Single-Anchor Repair of a Superior Third Subscapularis Tear Using a Self-Punching Knotless Soft Suture Anchor

Numerous techniques exist for arthroscopic subscapularis repair with varying degrees of complexity based on tear morphology, all of which have established satisfactory outcomes in function and patient satisfaction. Arthroscopic subscapularis repair can require several working portals and suture anchors, increasing both technical complexity and operative time. This Technical Note describes an arthroscopic repair of a superior one-third subscapularis tear using a self-punching knotless soft suture anchor through a single anterior working portal. Thus, we offer a unique approach to arthroscopic repair of superior one-third subscapularis tears that is time-saving, reproducible, and highly efficient while minimizing iatrogenic damage and postoperative complications.

Subscapularis (SSC) tendon tears: diagnostic performance and reliability of magnetic resonance arthrography (MRA) with arthroscopic correlation and comparison with clinical tests

OBJECTIVE

To evaluate the diagnostic performance and reliability of magnetic resonance of arthrography (MRA) in diagnosis of subscapularis (SSC) tendon tears between two reviewers with varying levels of experience, and compare the results with clinical tests.

MATERIALS AND METHODS

SSC tendons were retrospectively evaluated in a total of 272 patients with arthroscopic confirmations. A total of 548 shoulder MRAs were evaluated by two musculoskeletal radiologists, and SSC tendon pathologies were classified into three groups: intact tendon (n = 149), partial-thickness tear (n = 92), or full-thickness tear (n = 31). Diagnostic performance was determined using arthroscopy as gold standard and compared with results of four clinical tests. Intra- and inter-observer reliabilities of two reviewers were evaluated using kappa statistics.

RESULTS

For full-thickness tears, mean values of sensitivity, specificity, and accuracy of reviewer 1/reviewer 2 were 71.0%/87.1%, 97.3%/98.3%, and 94.4%/95.5%, respectively. For partial-thickness tears, mean values of sensitivity, specificity, and accuracy were 72.8%/73.4%, 78.3%/81.2%, and 76.5%/78.5%, respectively. Intra- and inter-observer reliabilities for both reviewers were good to very good (k = 0.85/0.93, p < 0.001; k = 0.74-0.89, p < 0.001). For all clinical tests, while specificity was very high, sensitivity was very low and the overall accuracy was also low.

CONCLUSION

MRA showed high diagnostic performance for the diagnosis of SSC tendon tears, especially full-thickness tears, with good inter- and intra-observer reliabilities, regardless of the level of experience of the reviewer.

Arthroscopic Subscapularis Repair Using a Clever Hook and Lasso Loop Technique in the Beach Chair Position: A Simple and Reproducible Guide

Addressing subscapularis tendon pathology has garnered increased attention during shoulder arthroscopy in attempt to adequately restore glenohumeral force couples. The appropriate rebalancing of force couples of the rotator cuff musculature by repairing subscapularis tendon tears in patients with large rotator cuff tears has been shown to improve functional outcomes while decreasing retear rates. However, subscapularis tendon tears may be particularly challenging to diagnose and present a significant degree of technical difficulty with the description of multiple arthroscopic and open surgical techniques. In this comprehensive guide, we put forth a simple, concise, and reproducible arthroscopic technique using a Clever Hook and Lasso Loop stitch technique for repairing both high-grade partial and full-thickness tears of the subscapularis tendon.

A very rare case of an accessory subscapularis muscle and its potential clinical significance

The subscapularis muscle is the largest muscle of the rotator cuff and its main function is internal rotation. It is morphologically variable in both point of origin and insertion. The presence of an accessory subscapularis muscle can lead to brachial plexus neuropathy. This report presents a very rare accessory subscapularis muscle originating from two distinct bands on the subscapularis and teres major muscles. The insertion was divided among four tendons. The fourth tendon is bifurcated. One of these was connected to the tendon of the subscapularis muscle and the other three inserted into the base of the coracoid process of the scapula. This anomalous muscle has the potential to entrap the nerves of the posterior cord such as the axillary, lower subscapular, and thoracodorsal nerves.

Physical therapy and precision rehabilitation in shoulder rotator cuff disease

PURPOSE

To describe the main features of the rehabilitation protocols for RC disease based on the phases of tendon healing and to investigate about the use of wearable devices as monitoring systems.

METHODS

We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL, and EMBASE databases using various combination of the keywords "rotator cuff," "rotator cuff tear," "rehabilitation protocol," "accelerated," "conservative," "stiffness," "exercises," and "wearable devices." All articles concerning precision orthopaedic rehabilitation therapy in rotator cuff disease were retrieved.

RESULTS

To date, rehabilitation protocols are not comparable due to wide heterogeneity of RC diseases. Wearable technologies are becoming a revolutionary tool for movement and posture monitoring.

CONCLUSION

Rehabilitation protocols for RC disease should be tailored on the basis of the different phases of tendon healing. Wearable devices hold the promise to offer a new outlook for long-term follow-up during the postoperative period providing information to the clinician about patient's status.

Floating Subscapularis Tear: A Variation of the Partial Subscapularis Tear

A variation of subscapularis tear has been identified, named floating subscapularis, where the tendon is completely detached from the lesser tuberosity but is continuous with the tissue covering the bicipital groove. An accurate diagnosis can be made using arthroscopic observation with passive external and internal rotation of the affected shoulder, which shows mismatched movement between the humerus and the subscapularis tendon. The purpose of this study is to examine the prevalence of this particular tear pattern. Clinical records during the study period (from January 2011 to December 2017) were retrospectively examined. Overall, 1295 arthroscopic rotator cuff repair procedures were performed. Among these, the subscapularis tendon was repaired in 448 cases, and 27 cases were diagnosed as floating subscapularis. The prevalence of floating subscapularis was 6% in the subscapularis repair population. This particular tear pattern has not previously been described and it seems to be ignored. The floating subscapularis is thought to be the tear of the deep layer preserving the superficial layer connected to the greater tuberosity by fibrous extension of the soft tissue covering the bicipital groove.

Patient-Reported Outcomes After Isolated and Combined Arthroscopic Subscapularis Tendon Repairs

PURPOSE

To analyze minimum 2-year postoperative patient-reported outcomes of a large group of patients after arthroscopic subscapularis (SSc) repair with respect to surgical findings and concurrent procedures.

METHODS

Patients who underwent arthroscopic SSc repair from January 2010 to April 2016 completed the Patient-Reported Outcomes Measurement Information System for Upper Extremity (PROMIS-UE) test and postoperative visual analog scale pain score. Medical records were reviewed for the preoperative visual analog scale pain score and surgical findings. SSc tears were considered partial or complete. Concomitant pathology and treatment of the supraspinatus (SS), infraspinatus (IS), and biceps tendon were recorded. We compared preoperative variables and outcomes between isolated partial SSc repair, partial SSc with SS and/or IS repair, isolated complete SSc repair, and complete SSc with SS and/or IS repair.

RESULTS

One hundred forty-five shoulders were included with an average age of 62.0 ± 9.8 years and average follow-up period of 52.2 ± 19.5 months. A significant reduction in the pain score occurred, from 4.8 (95% confidence interval [CI], 4.4-5.2) to 0.9 (95% CI, 0.6-1.1) (P < .001), with a mean postoperative PROMIS-UE score of 50.7 (95% CI, 49.5-52.0). Most SSc tears were partial with SS and/or IS repair (44.1%). Isolated partial SSc tears (29.9%), complete SSc tears with SS and/or IS repair (20.1%), and isolated complete SSc tears (5.9%) were less common. A significant difference in the mean postoperative PROMIS-UE score was not found between groups (P = .609). Biceps tendon pathology was significantly more common in complete SSc tears than partial SSc tears (P < .001), but there was no difference in the rate of biceps intervention (P = .110) or the PROMIS-UE score based on biceps intervention (P = .471).

CONCLUSIONS

We observed significant improvements in pain and patient-reported outcomes in line with population means for a large group of patients after SSc tendon repair. Importantly, outcomes were similar despite the size of SSc tear or concurrent SS and/or IS repairs. Biceps pathology was common, and neither its presence nor its treatment influenced postoperative patient outcomes.

LEVEL OF EVIDENCE

Level IV, retrospective case series.