Arthroscopic visualization of the subscapularis tendon

Arthroscopic Modified Subacromial Viewing Portal Repair of Upper Third of Subscapularis Tendon Partial-Thickness Tears

At present, the repair pattern of upper third of subscapularis tendon partial-thickness tears (upper-third tendon tears) is performed in the glenohumeral joint and conventional subacromial viewing portal, but the visualization of subscapularis tendon and footprint is poor when using a 30° scope. The modified subacromial viewing portal presented in this Technical Note is a modified surgical technique for the repair of upper-third tendon tears. Since the scope forms an angle of 70° with the subscapularis tendon and footprint of lesser tuberosity, satisfactory visualization can be obtained when using 30° scope; the predesigned surgical portal and working space without bony barrier can offer a smooth surgical procedure. Our surgical technique is described in pearls, pitfalls, advantages, and disadvantages.

Quantification of the Field of View for Standard Lateral Arthroscopy of the Canine Shoulder

OBJECTIVE

 The aim of this study was to define the extent of the biceps tendon, subscapularis tendon, and cranial border of the medial glenohumeral ligament within the field of view during standard lateral shoulder arthroscopy in the dog. We also examine the effect of joint flexion on the field of view of the biceps tendon.

STUDY DESIGN

 This was a cadaveric study using 21 shoulders of large breed dogs. Each shoulder was explored with a 30-degree arthroscope using standard lateral ports. For each supporting structure, the margins within the arthroscopic field of view were marked with ink. In 11 shoulders, the distal margin of the biceps tendon was identified and marked first with the limb at a standing angle and then in flexion. The margins of the cranial border of the medial glenohumeral ligament were marked at the standing angle. In 10 additional shoulders, the margins of the subscapularis tendon were evaluated. Each joint was fully dissected and the portion of each stabilizing structure within the field of view was quantified.

RESULTS

 Fifty-eight percent of the cranial border of the medial glenohumeral ligament was within the arthroscopic view. At a standing angle, 48% of the intra-articular length of the biceps tendon was within the arthroscopic view, compared to 63% with the limb flexed. Twenty percent of the subscapularis tendon was within the arthroscopic view.

CONCLUSION

 A significant portion of the biceps tendon and medial stabilizing structures of the canine shoulder are outside the field of view of arthroscopy through a standard lateral approach. The limitations of the arthroscopic field of view should be appreciated when evaluating the shoulder.

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.

Diagnostic performance of conventional magnetic resonance imaging for detection and grading of subscapularis tendon tear according to Yoo and Rhee classification system in patients underwent arthroscopic rotator cuff surgery

OBJECTIVES

To assess the diagnostic accuracy of conventional MRI for detecting and grading subscapularis (SSC) tears by applying the Yoo and Rhee classification.

MATERIALS AND METHODS

A total of 179 patients who underwent MRI followed by arthroscopic rotator cuff surgery were enrolled. Two musculoskeletal radiologists evaluated the SSC using axial, oblique sagittal, and oblique coronal MRI according to the Yoo and Rhee classification. Using arthroscopic findings as the reference standard, the sensitivity, specificity, accuracy, and interobserver agreement of SSC tears were analyzed.

RESULTS

Arthroscopy confirmed that the numbers of type I, IIA, IIB, III, IV, and V tears were 35, 70, 35, 9, 9, and 0, respectively. The sensitivity, specificity, and accuracy of readers 1 and 2 for the detection of tears (type IIA or higher) were 85%, 75%, and 82%, and 89%, 70%, and 83%, respectively, while those for the detection of surgical candidates (type IIB or higher) were 77%, 75%, and 75%, and 77%, 83%, and 82%, respectively. The interobserver agreement for detecting SSC tear presence was substantial (κ = 0.70) for reader 1 vs. reader 2, and those for detecting the surgical candidate group was substantial (κ = 0.68) for reader 1 vs. reader 2. The interobserver agreement for grading SSC tears was excellent (κ = 0.86) for reader 1 vs. reader 2.

CONCLUSION

Conventional MRI showed 82.5% and 78.5% average accuracy in detecting IIA and IIB or higher tears by applying the Yoo and Rhee classification for the diagnosis of SSC tears with an excellent interobserver agreement in tear grading.

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.

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.

Evaluating subscapularis tendon tears on axillary lateral radiographs using deep learning

OBJECTIVE

To develop a deep learning algorithm capable of evaluating subscapularis tendon (SSC) tears based on axillary lateral shoulder radiography.

METHODS

A total of 2,779 axillary lateral shoulder radiographs (performed between February 2010 and December 2018) and the patients' corresponding clinical information (age, sex, dominant side, history of trauma, and degree of pain) were used to develop the deep learning algorithm. The radiographs were labeled based on arthroscopic findings, with the output being the probability of an SSC tear exceeding 50% of the tendon's thickness. The algorithm's performance was evaluated by determining the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, negative predictive value (NPV), and negative likelihood ratio (LR-) at a predefined high-sensitivity cutoff point. Two different test sets were used, with radiographs obtained between January and December 2019; Test Set 1 used arthroscopic findings as the reference standard (n = 340), whereas Test Set 2 used MRI findings as the reference standard (n = 627).

RESULTS

The AUCs were 0.83 (95% confidence interval, 0.79-0.88) and 0.82 (95% confidence interval, 0.79-0.86) for Test Sets 1 and 2, respectively. At the high-sensitivity cutoff point, the sensitivity, NPV, and LR- were 91.4%, 90.4%, and 0.21 in Test Set 1, and 90.2%, 89.5%, and 0.21 in Test Set 2, respectively. Gradient-weighted Class Activation Mapping identified the subscapularis insertion site at the lesser tuberosity as the most sensitive region.

CONCLUSION

Our deep learning algorithm is capable of assessing SSC tears based on changes at the lesser tuberosity on axillary lateral radiographs with moderate accuracy.

KEY POINTS

• We have developed a deep learning algorithm capable of assessing SSC tears based on changes at the lesser tuberosity on axillary lateral radiographs and previous clinical data with moderate accuracy. • Our deep learning algorithm could be used as an objective method to initially assess SSC integrity and to identify those who would and would not benefit from further investigation or treatment.

Diagnostic accuracy of ultrasound in subscapularis tendon abnormalities and the importance of operator experience

OBJECTIVE

This study aimed to investigate the reasons behind the compliance, diagnostic success, and failure of ultrasound (US) examinations of two radiologists with reference to magnetic resonance imaging (MRI) in the abnormalities of subscapularis (SSC) tendon, including tendinosis.

METHODS

One less experienced radiologist (operator-1) and one senior radiologist, experienced in the musculoskeletal US (operator-2), performed the shoulder US on 78 patients (mean age: 53.18 ± 10.89 [22-73] years), who had undergone MRI for routine reasons except malignancy, within 1-4 weeks of MRI. Tendinopathy, partial (PT), or full-thickness (FT) tears were recorded in the subscapularis. The thickness of the anterior and lateral soft tissues in the shoulder girdle was measured by MRI. The inter-operator agreement on the US results, the US-MRI compliance for each operator, and the relationship between the US-MRI compliance and tissue thickness were investigated.

RESULTS

The inter-operator agreement on the US findings was moderate. The US-MRI compliance was fair for operator-1, but substantial for operator-2. The circumferential soft tissue thickness and US-MRI compliance were not correlated (p>0.05). The interobserver agreement in US was moderate (K: 0.415). The US-MRI compliance was fair for operator-1 (K: 0.344) and substantial for operator-2 (K: 0.616). The accuracy rates for the differentiation of normal tendon, tendinosis, PT, and FT were 59%, 75%, 72%, and 100%, respectively, for operator-1 and 87%, 83%, 85%, and 100%, respectively, for operator-2. However, the respective sensitivity of operator-1 was 46%, 19%, 44%, and 100%; and operator-2 was 91%, 67%, 82%, and 100%. The diagnostic performance of operator-1 was lower, except for FT.

CONCLUSION

The thickness of the surrounding tissue does not affect the US results. The differentiation between tendinosis and PT tear is difficult (more prominent in less experienced user); however, because this would not change the treatment choice, shoulder US is recommended after basic training in subscapularis pathologies.

LEVEL OF EVIDENCE

Level II, Diagnostic.

Arthroscopic Subscapularis Repair Using a Subacromial View

As a result of the continued improvement in arthroscopic equipment and techniques, subscapularis tears are now more reliably identified and are being repaired at higher rates than previously reported. Whereas small upper-border subscapularis tears can usually be effectively managed using an intra-articular view, larger tears often cannot be fully visualized with a standard 30° arthroscope when viewed from the posterior portal. These tears may require either using a 70° arthroscope or viewing through the standard 30° arthroscope from a subacromial portal-site location to completely visualize the tear. This article illustrates and discusses the advantages of using a subacromial-space portal site to view and arthroscopically manage large subscapularis tears.

Arthroscopic visualization of the medial collateral ligament of the elbow

BACKGROUND

This study aimed to determine the extent to which the medial collateral ligament (MCL) can be visualized during a standard posterior arthroscopic view of the elbow.

METHODS

Eight fresh human cadaveric elbows were placed in a simulated lateral decubitus position. Standard elbow arthroscopy was performed on each specimen using a standard posterior portal for visualization with a 30° arthroscope. The most distal borders of the visible part of the MCL were marked using a spinal needle and tagged using nylon sutures. Subsequently, the elbow was dissected. The overall surface area of the entire MCL and that defined by the suture tags were calculated for each specimen.

RESULTS

The mean area of the visible part of the MCL represented 48% of the mean overall area. The arthroscopically tagged part of the posterior band of the MCL represented <50% of the entire MCL. Arthroscopic visualization was not available for most of the posterior bands of the MCL.

CONCLUSIONS

Less than half of the MCL is visible with a 30° arthroscope from standard posterior portal. Thus, sole reliance on arthroscopic visualization with this manner is not enough to release of the MCL. The variable effort is required to improve the limited visualization during the procedure. Moreover, the individual attention is essential to protect the ulnar nerve because the ulnar nerve is very close to the MCL especially to the anterior band.

Rotating Arm Internally Can Change the Arthroscopic Diagnosis of a Partial-thickness Tear of the Subscapularis

Background

The aims of this study were (1) to examine the footprint of the subscapularis tendon using the traditional posterior portal and 30° arthroscope by simple internal rotation of the arm during surgery, and (2) to classify the pattern of a subscapularis partial-thickness tear.

Methods

This study analyzed a total of 231 patients with a partial-thickness subscapularis tear from 550 consecutive patients undergoing an arthroscopic operation who had a visualization of the subscapularis tendon footprint by internal rotation of the arm. First, the patients were classified into four categories according to the tear pattern: (1) stable lamination, (2) unstable lamination, (3) avulsion, and (4) laminated avulsion. Randomized arthroscopic videos were reviewed blindly by two independent orthopedic surgeons. The pattern of the tear of the subscapularis at the neutral position and after internal rotating the arm were assessed and compared with the treatment decision (level IV case series).

Results

Stable lamination, unstable lamination, avulsion, and laminated avulsion were observed in 9.1% (n=21), 20.8% (n=48), 41.1% (n=95), and 29.0% (n=67) of cases, respectively. In 145 out of 231 cases (62.8%), the decision was changed after inspecting the footprint after internal rotation of the arm, and the treatment method was changed in 116 (50.2%) cases.

Conclusions

In a subscapularis tendon partial-thickness tear, inspecting the footprint of the subscapularis tendon is essential to diagnosing and deciding on the appropriate treatment. In addition, simply internal rotating the arm during surgery when using the traditional posterior portal and 30° arthroscope can be a valuable method.

Clinical Outcomes and Tendon Integrity in Patients With Chronic Retracted Subscapularis Tear After Arthroscopic Single-Row Oblique Mattress Suture Repair Technique

PURPOSE

To evaluate clinical outcomes and tendon integrity in patients with chronic retracted subscapularis tears using an arthroscopic single-row oblique mattress suture repair technique.

METHODS

Patients with full-thickness subscapularis tears retracted to the glenoid level and with at least 2 years of follow-up were included. Tendon retraction level was measured on preoperative axial magnetic resonance images and confirmed during arthroscopic surgery. The subscapularis tendon was repaired arthroscopically using the single-row oblique mattress suture technique on the medial margin of the lesser tuberosity. Two double-loaded suture anchors were used to obtain firm fixation between the tendon and the footprint. Clinical outcomes were assessed for all patients preoperatively and postoperatively using active range of motion, a visual analog scale score for pain, and American Shoulder and Elbow Surgeons and Constant scores. To evaluate structural integrity of the repaired tendon, all patients underwent magnetic resonance imaging at 6 months and ultrasonography at 1 year after surgery.

RESULTS

The shoulder function of the 33 patients analyzed was improved significantly after a mean follow-up period of 26.3 ± 3.5 months compared with preoperative values (American Shoulder and Elbow Surgeons score of 52.0 ± 7.9 preoperatively vs 79.6 ± 7.0 at last follow-up, P < .001, and Constant score of 43.0 ± 13.4 preoperatively vs 76.7 ± 9.2 at last follow-up, P < .001). Postoperative active range of motion improved significantly in forward flexion, external rotation, and internal rotation (P < .001). The mean visual analog scale pain score decreased by 3.42 (5.2 ± 1.6 preoperatively vs 1.9 ± 1.4 at last follow-up, P < .001). In 4 patients (12.1%), subscapularis retears were confirmed on postoperative magnetic resonance imaging.

CONCLUSIONS

Despite significant retraction, arthroscopic repair using a single-row oblique mattress suture technique in patients who had chronic subscapularis tears with retraction to the glenoid level yielded satisfactory clinical outcomes and reliable tendon healing.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Accuracy of magnetic resonance imaging (MRI) for subscapularis tear: a systematic review and meta-analysis of diagnostic studies

INTRODUCTION

The accuracy of MRI for subscapularis tear is lower than that of overall rotator cuff tears. Until now, no systematic reviews and meta-analysis have been conducted to compile these data. The purpose of this study was to determine, through a systematic review and meta-analysis, the diagnostic accuracy of MRI in the detection of subscapularis tendon tears.

MATERIALS AND METHODS

A systematic review of PubMed, EMBASE, and MEDLINE databases up to April 2017 was performed. All studies assessing the sensitivity and specificity of the MRI (index test) compared to arthroscopic surgical findings (reference test) for subscapularis tendon tear were included. A meta-analysis was performed to calculate pooled sensitivity, specificity, sROC curve, and diagnostic odds ratio values.

RESULTS

A total of 497 citations were identified. After applying the eligibility criteria, 14 articles were included, including 1858 shoulders with 613 subscapularis tears. For overall subscapularis tears, sensitivity was 0.68 (95% CI 0.64-0.72) and specificity was 0.90 (95% CI 0.89-0.92). Sensitivity was 0.93 (95% CI 0.83-0.98) for full-thickness tears and 0.74 (95% CI 0.66-0.82) for partial tears. Specificity was 0.97 (95% CI 0.94-0.98) for full-thickness tears and 0.88 (95% CI 0.85-0.91) for partial tears. Analyzing only studies with field of strength ≥ 1.5 T, sensitivity was 0.80 (95% CI 0.76-0.84) and specificity 0.84 (95% CI 0.81-0.87).

CONCLUSION

MRI is an accurate method for diagnosing subscapularis tendon tears; however, its accuracy is lower than that of overall rotator cuff tears, due to its lower sensitivity.

LEVEL OF EVIDENCE

III, systematic review of Level II and III studies.

Subscapularis Management in Total Shoulder Arthroplasty: Current Evidence Comparing Peel, Osteotomy, and Tenotomy

The optimal approach to management of the subscapularis in total shoulder arthroplasty (TSA) is controversial. Options include the subscapularis tenotomy, lesser tuberosity osteotomy (LTO), and peel. This review provides a summary of subscapularis anatomy and function, outcomes associated with subscapularis management options in TSA, and postoperative subscapularis deficiency. Based on the available literature, LTO appears to result in improved function and subscapularis integrity relative to tenotomy, while peel and LTO have generally led to equivalent outcomes. The highest level of evidence to date is derived from a randomized controlled trial that demonstrated that outcomes following peel and LTO were not significantly different. There is currently a paucity of high-quality evidence as most studies have consisted of small retrospective series with varying outcome measures. Furthermore, the optimal approach to establishing the diagnosis of subscapularis deficiency following TSA is unclear.

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.

Subscapularis tendon tears: Management and arthroscopic repair

Tears of the subscapularis tendon have been under-recognised until recently. Therefore, a high index of suspicion is essential for diagnosis.A directed physical examination, including the lift-off, belly-press and increased passive external rotation can help identify tears of the subscapularis.All planes on MR imaging should be carefully evaluated to identify tears of the subscapularis, retraction, atrophy and biceps pathology.Due to the tendency of the tendon to retract medially, acute and traumatic full-thickness tears should be repaired. Chronic tears without significant degeneration should be considered for repair if no contraindication exists.Arthroscopic repair can be performed using a 30-degree arthroscope and a laterally-based single row repair; one anchor for full thickness tears ⩽ 50% of tendon length and two anchors for those ⩾ 50% of tendon length.Biceps pathology, which is invariably present, should be addressed by tenotomy or tenodesis.Timing of post-operative rehabilitation is dictated by the size of the repair and the security of the repair construct. The stages of rehabilitation typically involve a period of immobilisation followed by range of movement exercises, with a delay in active internal rotation (IR) and strengthening in IR. Cite this article: EFORT Open Rev 2017;2:484-495. DOI: 10.1302/2058-5241.2.170015.

Isolated lesions of the lower subscapularis tendon: diagnosis and management

PURPOSE

Isolated lesions of the caudal portion of the subscapularis (SSC) tendon are rare and have not been subject of major attention in the literature yet. However, these lesions can lead to tremendous impairment of shoulder function. The purpose of the present study was to raise clinician's awareness for these "hidden lesions" and to present the crucial steps for diagnosis and management.

METHODS

Five patients (three men, two women; mean age 40) with traumatic isolated caudal SSC lesion were enrolled in the present study. After clinical and radiological examination, all patients underwent diagnostic arthroscopy and open inferior SSC repair. The results of the clinical and radiological examination were documented along with the intraoperative findings. Post-operative pain level and shoulder function were assessed.

RESULTS

In all patients the SSC lesion could be detected clinically. In two patients the caudal SSC tear was diagnosed delayed after initial conservative treatment. Preoperatively, all patients showed restricted active movement of the shoulder with positive clinical tests for the SSC. All SSC lesions could be detected on MR images and identified arthroscopically. After a mean follow-up of 12 months, all clinical SSC tests were negative, and the patients have almost regained preinjury shoulder function. The mean post-operative pain score (VAS) was 1 (range 0-1), and the mean ASES score was 93.3 (range 91.6-95).

CONCLUSION

Arthroscopic visualization of the SSC tendon is incomplete rendering caudal SSC tears difficult to detect and easy to overlook. Clinicians' awareness of this pathology along with accurate clinical and radiological examination leads to the correct diagnosis. Open caudal SSC repair provides pain relief and reliable shoulder function after short-term follow-up.

LEVEL OF EVIDENCE

IV.

Long-term Results After Arthroscopic Repair of Isolated Subscapularis Tears

BACKGROUND

Although some reports have presented short- to midterm results after arthroscopic repair of isolated subscapularis (SSC) tendon tears, long-term evaluation is still lacking.

HYPOTHESIS

Long-term results after arthroscopic repair of isolated SSC tears are comparable with the functional and radiological short- to midterm outcomes described in the literature.

STUDY DESIGN

Case series, Level of evidence, 4.

METHODS

This study assessed 17 patients (5 females and 12 males; mean age, 45.6 years) with isolated SSC tears (Fox and Romeo classification types 2-4) who underwent all-arthroscopic suture anchor repair. The mean interval from symptom onset to the time of surgery was 5.3 months in 16 patients (94.1%). One patient (5.9%) was symptomatic for a prolonged period (104 months) before surgery. All patients were assessed with a clinical examination preoperatively. SSC function was investigated using specific clinical tests and common scoring systems, including Constant, American Shoulder and Elbow Surgeons (ASES), Disabilities of the Arm, Shoulder and Hand (DASH), and Simple Shoulder Test (SST) scores. At follow-up, muscular strength was evaluated using an electronic force-measuring plate. Structural integrity of the repair was assessed using magnetic resonance imaging (MRI).

RESULTS

At a mean follow-up of 98.4 ± 19.9 months, the mean Constant score improved from 47.8 preoperatively to 74.2 postoperatively ( P = .001). Higher Constant ( P = .010) and ASES ( P = .001) scores were significantly associated with a shorter time from symptom onset to surgery. The size of the SSC lesion did not correlate with any clinical score outcome ( P = .476, .449, .985, and .823 for Constant, ASES, DASH, and SST scores, respectively). Three patients (17.6%) had persistent positive clinical test results (belly-press/lift-off). Compared with the uninjured contralateral side, SSC strength was significantly reduced in the belly-press position ( P = .031), although active internal ( P = .085) and external ( P = .093) rotation was not affected. In 1 patient, a rerupture was detected by MRI. Six patients had cranial SSC atrophy. Overall, 88.2% of patients were "very satisfied" or "satisfied" with their results.

CONCLUSION

Arthroscopic repair of isolated SSC tears results in significant clinical improvements and enduring tendon integrity, although SSC strength remains reduced in the long term. Early surgical treatment seems to be a relevant factor allowing good shoulder function.

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.

Diagnostic Performance of MR Arthrography with Anterior Trans-Subscapularis versus Posterior Injection Approach for Subscapularis Tendon Tears at 3.0T

OBJECTIVES

To compare the diagnostic performance of shoulder magnetic resonance arthrography (MRA) with the anterior trans-subscapularis versus posterior injection approach to diagnose subscapularis tendon (SCT) tears.

METHODS

One hundred and sixty-seven arthroscopically confirmed patients (84 anterior and 83 posterior approaches) were included. Two readers retrospectively scored SCT tears. Proportions of correctly graded tears between MR arthrography and arthroscopy were calculated. Retrospective error analysis was performed.

RESULTS

The sensitivity and specificity were 80 % (24/30) and 72 % (39/54) by reader 1, 73 % (22/30) and 76 % (41/54) by reader 2 in the anterior approach, and 86 % (30/35) and 79 % (38/48) by reader 1, 80 % (28/35) and 88 % (42/48) by reader 2 in the posterior approach, respectively. There were no significant differences in sensitivity and specificity between the two groups. Proportions of correctly graded tears of both readers were 48 % and 36 % in the anterior approach, and 70 % and 68 % in the posterior approach, respectively. The intratendinous collection of contrast material was not statistically significantly different between anterior (n = 8) and posterior (n = 3) approach group.

CONCLUSIONS

For the MRA diagnosis of SCT tears, there was no significant difference between the anterior trans-subscapularis and the posterior approach.

KEY POINTS

• Anterior trans-subscapularis and posterior approaches showed no significant difference for SCT tears • Intratendinous collection of gadolinium is more frequent in anterior trans-subscapularis approach • Extent of SCT tears tends to be overestimated in anterior trans-subscapularis approach • Posterior approach should be considered for diagnosing SCT tear.

Poor Agreement on Classification and Treatment of Subscapularis Tendon Tears

PURPOSE

To assess the inter- and intraobserver agreement for classification and management of subscapularis tendon pathology based on arthroscopy and magnetic resonance imaging (MRI).

METHODS

Twenty-two orthopaedic surgeons from the Multicenter Orthopaedic Outcomes Network (MOON) shoulder group reviewed still arthroscopic and MRI images of the subscapularis tendon from patients with a random assortment of subscapularis morphology. The surgeons were asked to classify the pathology based on 2 systems (Lafosse and Lyons) and choose whether they would repair the tendon and, if so, the method of repair (open or arthroscopic). The survey was administered 3 times to each surgeon. Inter- and intraobserver reliability between testing rounds was determined by kappa analysis.

RESULTS

Interobserver reliability on classification of tears was poor based on MRI (k = 0.18 to 0.19) and fair based on arthroscopy (k = 0.26 to 0.29). Interobserver agreement on whether surgical treatment was indicated was fair for both MRI (k = 0.28) and arthroscopy (k = 0.38), while the agreement for type of surgery was poor based on MRI (k = 0.18) and fair based on arthroscopy (k = 0.28). Interobserver agreement did not improve when both MRI and arthroscopy were provided simultaneously (k = 0.24 to 0.30). Intraobserver reliability for classification and treatment was fair to moderate for both MRI (k = 0.32 to 0.50) and arthroscopic imaging (k = 0.39 to 0.56). When considering just those patients with normal tendons, surgeon agreement improved. For all questions, the arthroscopic images had a higher level of agreement among surgeons than the MRI (P < .001).

CONCLUSIONS

Although surgeons tended to have higher reliability when presented with arthroscopic images compared with MRI, there was very little agreement on the classification and management of subscapularis tendon tears.

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.

MRI-Arthroscopy Correlation for Shoulder Anatomy and Pathology: A Teaching Guide

OBJECTIVE

The objectives of the article are to improve the radiologist's understanding of shoulder arthroscopy and see how it correlates with MRI. We review the basic principles of arthroscopy followed by a comparison of its strengths and weaknesses relative to MRI. This discussion is supplemented by a series of cases that show the relationship between arthroscopy and MRI in terms of the visualization of normal and abnormal anatomy in the diagnosis of common shoulder abnormalities.

CONCLUSION

By understanding what our orthopedic colleagues are seeing (and not seeing) during arthroscopic shoulder surgery, we can better understand the strengths and weaknesses of MRI, which provides us the opportunity to improve our imaging interpretations and produce valuable management-guiding diagnostic reports.

The influence of partial subscapularis tendon tears combined with supraspinatus tendon tears

BACKGROUND

With the advent of arthroscopy, more partial subscapularis tears are being recognized. The biomechanical effects of partial subscapularis tears are unknown, and there is no consensus as to their treatment. Therefore, the objective of this study was to evaluate and to quantify the changes in range of motion and glenohumeral kinematics for isolated subscapularis partial tears, combined subscapularis and supraspinatus tears, supraspinatus repair, and combined supraspinatus and subscapularis repair.

METHODS

Six cadaveric shoulders were tested in the scapular plane with 0°, 30°, and 60° shoulder abduction under 6 conditions: intact; ¼ subscapularis tear; ½ subscapularis tear; ½ subscapularis and complete supraspinatus tear; supraspinatus repair; and supraspinatus and subscapularis repair. Maximum internal and external rotation and glenohumeral kinematics were measured under physiologic muscle loading condition. A repeated measures analysis of variance with a Tukey post hoc test was used for statistical analysis.

RESULTS

Maximum external rotation was significantly increased after ¼ subscapularis tear at 30° abduction and in all abduction angles with ½ subscapularis tear (P < .05). The 2 repair conditions did not restore external rotation to the intact level. At maximum internal and external rotation, there was a significant superior shift in the humeral head apex position with ¼ subscapularis tear at 30° abduction and with ½ subscapularis tear at 60° abduction (P < .05). Repair of the supraspinatus tendon partially corrected abnormal kinematics; however, neither repair restored abnormal kinematics to intact.

CONCLUSION

Additional repair of the partial subscapularis tear with supraspinatus tear did not affect external rotation or glenohumeral kinematics. Further studies are needed to evaluate different subscapularis repair techniques.

LEVEL OF EVIDENCE

Basic science study, biomechanics.

Correlation of MRI with arthroscopy for the evaluation of the subscapularis tendon: a musculoskeletal division’s experience

OBJECTIVE

To determine the accuracy of MR imaging for the evaluation of the subscapularis tendon as well as define imaging findings that will increase accuracy.

MATERIALS AND METHODS

Retrospective review of the MR and operative (OR) reports of 286 patients was conducted and reviewed for the presence/degree (partial (PT)/full-thickness (FT)) of tearing; only PT articular tears were included. The presence of a supraspinatus tear and time interval between surgery and MRI were also documented. All of the PT tears called on MRI were also reviewed to see if there was a statistically significant association between certain imaging characteristics and the presence of a tear in surgery. Statistical analysis included 95 % confidence intervals, Fisher’s exact, and exact Mann–Whitney tests.

RESULTS

A total of 244 patients were included in the study with a total of 25 subscapularis tears, 16 PT and nine FT, and 219 intact tendons in arthroscopy; 20/25 tears and 200 intact sensitivity of 80%, specificity of 91%, accuracy of 90%, positive predictive value of 51%, and negative predictive value of 98 %. There was a significant association between the presence of a PT tear during arthroscopy and fluid-like signal within the tendon on more than one imaging plane (p<0.001) with an accuracy of 90%.

CONCLUSIONS

This study reflects a musculoskeletal radiology section’s experience with the diagnosis of subscapularis tendon pathology, demonstrating that MRI could be used to accurately evaluate the subscapularis tendon. An understanding of certain imaging pitfalls and the presence of fluid-like signal on multiple imaging planes should increase the diagnostic accuracy of the radiologist evaluating the subscapularis tendon for the presence of a tear.

Reproducibility and reliability of subscapularis tendon assessment using CT-arthrography

BACKGROUND

Computed tomography (CT) coupled with arthrography remains the reference standard for the preoperative evaluation of rotator cuff tears. The objectives of this study were to evaluate intra-observer and inter-observer reproducibilities of CT-arthrographic assessment of the subscapularis tendon and to assess the validity and reliability of this investigation.

HYPOTHESIS

CT-arthrography is reliable and reproducible for the preoperative characterisation of subscapularis tendon lesions.

MATERIAL AND METHODS

We retrospectively reviewed 67 shoulders with rotator cuff tears in one or more tendons managed by arthroscopy, both to confirm the diagnosis and to allow therapeutic interventions. Each of the 67 preoperative CT-arthrograms was evaluated by three readers, of whom the first two evaluated the images twice at an interval of 30 days. The following were recorded at each reading: partial- or full-thickness tear in one or more rotator cuff tendons, intra-tendinous delamination, tendon stump retraction, and fatty degeneration of the muscles. The position of the long head of biceps tendon was assessed. A statistical analysis was performed using Fleiss' method to compute intra-observer and inter-observer variabilities in CT-arthrography assessment of the subscapularis tendon status. Validity of this assessment was measured by computing the concordance coefficients between CT-arthrography and arthroscopy.

RESULTS

Specificity of CT-arthrography was satisfactory for assessing the subscapularis tendon. Sensitivity was low. Significant inter-observer and intra-observer variabilities were documented. The concordance coefficients between CT-arthrography and arthroscopy indicated that major differences were common with all three readers. When assessing the subscapularis tendon by CT-arthrography, all readers experienced difficulties in distinguishing intact tendons, delaminated tendons, and tendons with tears confined to the upper third.

DISCUSSION

Although CT-arthrography remains the reference standard for the preoperative investigation of rotator cuff tears, significant variability occurs in assessing the continuity of the subscapularis tendon. Reliability of this assessment is not optimal, as shown by our evaluation of concordance with arthroscopy. Although our data should be interpreted in the light of the investigation and measurement biases present in our study, they suggest that CT-arthrography may fail to provide a valid and reproducible assessment of the subscapularis tendon. The development of magnetic resonance (MR) imaging and MR-arthrography will probably improve the preoperative evaluation of subscapularis tears in the near future.

LEVEL OF EVIDENCE

Level III; diagnostic value study.

New endoscopic classification for subscapularis lesions

BACKGROUND

The absence of a coherent classification system has hampered communication about the treatment and outcomes of the various types of subscapularis tendon lesions. In addition, a reliable classification system allows comparisons of epidemiological and therapeutic data. The classification systems used until now fail to incorporate the radiological and intraoperative abnormalities of the bicipital sling, and they do not consider the degree of subscapularis tendon cleavage. Here, we describe a new arthroscopy-based classification system intended for therapeutic and prognostic purposes.

METHODS

A prospective multicentre study sponsored by the French Society for Arthroscopy was conducted from March 2010 to January 2011 in 150 isolated subscapularis lesions with or without limited anterosuperior involvement. The bicipital sling and insertion of the deep subscapularis layer were routinely investigated by arthroscopy with video recording. Each lesion was classified after a consensus was reached among four surgeons.

RESULTS

We identified four lesion types based on the bicipital sling findings. Type I was defined as partial separation of the subscapularis tendon fibres from the lesser tuberosity with a normal bicipital sling. Type II consisted of a partial subscapularis tear at the lesser tuberosity attachment combined with partial injury to the anterior wall of the bicipital sling, without injury to the superior glenohumeral ligament. Type III was complete separation of the subscapularis fibres from the lesser tuberosity with extensive cleavage of the bicipital sling. Finally, in Type IV, all the subscapularis fibres were detached and, in some cases, conjunction of the subscapularis and supraspinatus fibres produced the comma sign. Nearly all the lesions identified intraoperatively during the study fit one of these four types.

DISCUSSION

A reproducible classification system that allows different surgeons to establish comparable homogeneous patient groups is useful for both therapeutic and prognostic purposes. We defined four types of subscapularis lesions that are easy to identify as either isolated lesions or combined with anterosuperior rotator cuff tears. Long head of biceps tendon abnormalities and fatty degeneration of the shoulder muscles can be added to our classification system. Studies of intraobserver and interobserver reproducibility are needed to complete the process of validating the diagnostic and/or prognostic usefulness of this new classification scheme.

MR imaging of subscapularis tendon injury in the setting of anterior shoulder dislocation

OBJECTIVE

To evaluate the degree and location patterns of subscapularis tendon injury in patients with prior anterior shoulder dislocation (ASD).

MATERIAL AND METHODS

Forty-five consecutive MR shoulder examinations in patients with a history of ASD and 20 consecutive MR examinations in patients without prior dislocation were reviewed. Two readers assessed for the presence and location of tendinosis and tearing in the subscapularis tendon, which was divided into three segments: superior, middle, and inferior. The readers also documented the presence of anterior labral tears, osseous Bankart defects and Hill-Sachs lesions. Fisher's exact tests were performed to analyze the different types of pathology and their locations.

RESULTS

Subscapularis tendinosis, and partial thickness and full thickness tears were more common in patients with a history of ASD. Tendinosis was found in 60-64.4% of the dislocation patients compared with 40% of the non-dislocation group. When stratified by location, the middle and inferior thirds were the most commonly affected with statistical significance (p < 0.05) found in tearing of the inferior third. Anterior labral tears, osseous Bankart defects, and Hill-Sachs lesions were more common in the dislocation group with statistically significant associations with tendinosis in the middle and inferior thirds and tearing of the middle third (p < 0.05).

CONCLUSION

Our study suggests an association between middle and inferior subscapularis tendon pathology and prior anterior shoulder dislocation. Based on our results, careful MR assessment of the subscapularis tendon by the radiologist is indicated in the setting of ASD as injury of this structure can be symptomatic and may be amenable to treatment.

The frequency of subscapularis tears in arthroscopic rotator cuff repairs: A retrospective study comparing magnetic resonance imaging and arthroscopic findings

PURPOSE

With the advent of arthroscopic shoulder surgery the comprehension and description of rotator cuff tears have strongly evolved. Subscapularis tears are difficult to recognize and are underestimated. Our purpose is to report our observations concerning the relative frequency of subscapularis tears in patients undergoing arthroscopic rotator cuff repair and to compare the arthroscopic observations with the magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

Retrospective cohort study including all patients undergoing arthroscopic rotator cuff repair was performed between March 2006 and March 2009 at our institution. Preoperative MRI findings, intraoperative arthroscopic findings, and details of surgical intervention were collected using medical charts.

RESULTS

We reviewed the medical charts of a total of 348 consecutive arthroscopic rotator cuff repairs. There were 311 supraspinatus tears (89%), 48 infraspinatus tears (14%), and 129 subscapularis tears (37%). MRI sensitivity and specificity were respectively 0.25 and 0.98 for subscapularis tendon tears, 0.67 and 1.0 for supraspinatus tears and 0.5 and 0.99 for infraspinatus tears.

CONCLUSION

Subscapularis tears are frequent lesions and usually appear concomitantly with supra or infraspinatus lesions. We propose a classification of subscapularis tendon tears, based on our observations of the pathoanatomy of the tears. While concordance with MRI results are good for the supraspinatus, MRI often fails to diagnose the presence of subscapularis tears and infraspinatus tears.

Cysts within and adjacent to the lesser tuberosity: correlation with shoulder arthroscopy

OBJECTIVE

The purpose of our study was to determine if cysts in and adjacent to the lesser tuberosity are associated with rotator cuff pathology found at arthroscopy.

MATERIALS AND METHODS

A retrospective review was undertaken of the magnetic resonance (MR) imaging of 286 consecutive arthroscopic procedures performed by a single orthopedic shoulder surgeon from February 2001 to June 2009. Images of the shoulders were reviewed by an experienced fellowship-trained musculoskeletal radiologist, reader 1, and a musculoskeletal fellow, reader 2, for the presence and location of lesser tuberosity cysts. Cysts were grouped by their location into those within the lesser tuberosity and those adjacent to the lesser tuberosity. Interreader agreement was calculated using kappa values.

RESULTS

A total of 26 patients (17 men, 9 women; age range 14–84 years; mean of 61 years) had cysts in or adjacent to the lesser tuberosity. For reader 1, patients with cysts located in the lesser tuberosity were found to be significantly older(p=00.03) and more likely to have subscapularis tendon tears(p=00.02) than patients with cysts located adjacent to the tuberosity. No significant difference in any category between patients with a cyst located in the lesser tuberosity and those adjacent to the tuberosity was identified for reader 2. Interreader agreement of imaging findings ranged from fair to near perfect agreement.

CONCLUSION

Cysts located in the lesser tuberosity at the insertion of the subscapularis tendon are suggestive of subscapularis tendon pathology and may occur in older individuals.

RESULTS FROM ARTHROSCOPIC REPAIR OF ISOLATED TEARS OF THE SUBSCAPULARIS TENDON

OBJECTIVE

To evaluate the functional and clinical outcomes and identify prognostic factors in patients undergoing arthroscopic repair of isolated tears of the subscapularis tendon.

METHODS

Between January 2003 and May 2009, we identified 18 shoulders with isolated tears or deinsertions that were complete or affected at least one third of the subscapularis tendon and underwent arthroscopic repair.

RESULTS

Three shoulders (17%) showed lesions in the upper third of the subscapularis; nine shoulders (50%) showed lesions in the upper two thirds; and six shoulders (33%) presented complete tears. In comparing the range of lateral rotation of the injured shoulder between before surgery and the time of the reevaluation, there was no statistical difference (p = 0.091). The LHBT was damaged in 11 shoulders (61%). According to the Constant score validation, we had excellent and good results in 83% of the cases and 17% were reasonable. The reevaluations on three patients showed re-tearing on MRI. Acromioplasty was performed on ten patients and this procedure did not represent statistical differences in the final results (p = 0.57).

CONCLUSIONS

There was no statistically significant difference in relation to preoperative lateral rotation between the injured shoulder and the contralateral side. There was no significant loss of lateral rotation after surgery. The LHBT may be normal in deinsertions of the subscapularis tendon. Acromioplasty did not influence the results. The re-tearing rate for arthroscopic repair of the subscapularis tendon was 16.6%.

Calcific tendonitis of the rotator cuff: an unusual case

Few case reports have described the surgical treatment of calcifying tendonitis of the subscapularis tendon. We present a case of symptomatic diffuse calcifying tendonitis involving the subscapularis and infraspinatus insertions that was difficult to detect arthroscopically. The patient was treated with arthroscopic incision of the tendinous insertions thorough removal of the calcific deposits and subsequent repair using a suture-anchor technique. Two years after the surgical procedure, the patient was completely pain-free and attained full range of motion. Radiographic evaluation performed 2 years after the procedure revealed no calcific deposits. We conclude that the combination of incision of the subscapularis and infraspinatus insertions, complete removal of the calcific deposits, and subsequent suture-anchor repair in an all-arthroscopic manner can lead to an excellent clinical outcome without compromising the functional integrity of the rotator cuff tendons.

Subscapularis function and structural integrity after arthroscopic repair of isolated subscapularis tears

BACKGROUND

Results of arthroscopic repair of isolated subscapularis tendon tears have not been widely studied. A detailed evaluation of subscapularis function with subscapularis strength quantification has not been performed to date.

PURPOSE

To evaluate postoperative subscapularis muscle function and to assess the clinical outcome and structural tendon integrity with postoperative magnetic resonance imaging after arthroscopic repair of isolated subscapularis tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

In a prospective study, isolated subscapularis tendon tears in 21 patients were treated with an all-arthroscopic repair. The average age of the study population was 43 years. The mean interval between trauma and surgery was 5.8 months. In 19 patients, a traumatic event caused the onset of symptoms. Subscapularis muscle function was assessed with specific clinical tests and the Constant scoring system. Postoperative subscapularis strength was evaluated with a custom-made electronic force measurement plate. All patients underwent postoperative magnetic resonance imaging to assess structural integrity of the repair.

RESULTS

The average duration of follow-up was 27 months. The Constant score increased from 50 points preoperatively to 82 points postoperatively (P < .01). Most positive preoperative lift-off and belly-press tests were reversed by surgery, with a rate of 5 (24%) persistent positive tests after surgery. In operated shoulders, subscapularis strength in the belly-press (65 vs 87 N; P < .05) and the lift-off position (44 vs 68 N; P < .05) was significantly reduced compared with the contralateral shoulder. Magnetic resonance imaging revealed an intact repair in 20 patients. Atrophy of the upper subscapularis muscle portion was present in about one-fourth of the patients and in all patients with a positive postoperative belly-press test.

CONCLUSION

Arthroscopic repair of isolated subscapularis tendon tears achieves substantial improvement of shoulder function and a low rerupture rate. Despite excellent clinical results, a significant postoperative subscapularis strength deficit compared with the contralateral shoulder persists that can be quantified with use of the force measurement plate. Atrophy of the upper subscapularis muscle is present in 25% of the patients in the postoperative course.

The subscapularis: anatomy, injury, and imaging

The subscapularis is the largest and most powerful of the rotator cuff muscles and fulfills an important role in glenohumeral movement and stability. The spectrum and implications of subscapularis muscle or tendon injury differ from injury to other rotator cuff components because of its unique structure and function. Diagnosing subscapularis injury is clinically difficult and assessment of subscapularis integrity may be limited during arthroscopy or open surgery. Diagnostic imaging plays an important part in diagnosing and evaluating the extent of subscapularis injury. The radiologist should be aware of the anatomy of the subscapularis, the variations in muscle or tendon injury, and the potential implications for treatment and prognosis.

Open repair of isolated traumatic subscapularis tendon tears

BACKGROUND

Diagnosis, operative treatment, and outcome assessment of isolated traumatic subscapularis tendon tears have not been widely studied.

PURPOSE

To report the clinical outcome, value of clinical tests, predictive outcome factors, and return to sports in the management of isolated traumatic subscapularis tendon tears.

STUDY DESIGN

Case series; level of evidence, 4.

METHODS

Thirty consecutive patients with a confirmed isolated subscapularis tear, except for associated biceps tendon injury or humeral avulsion of the glenohumeral ligaments (HAGL) lesions, found at arthroscopy were included in the study. The average age of the study population was 43.1 years. In all 30 patients, a traumatic event caused the onset of symptoms. The mean delay between trauma and surgery was 4 months. All patients underwent open tendon reconstruction with a suture anchor technique via a deltopectoral approach. Clinical assessment was done using the Constant score and specific subscapularis tests. Postoperative tendon integrity was assessed with ultrasound and magnetic resonance imaging. Sports activity, including competition level, sports discipline, and postoperative return to sports, was evaluated.

RESULTS

The average duration of follow-up was 46 months (range, 25-72 months). Seven patients had a full-thickness tear of the upper third of the tendon, 11 patients a full-thickness tear of the upper two-thirds of the tendon, and 12 patients had a complete subscapularis tendon tear. The Constant score increased from 51.3 preoperatively to 82.2 postoperatively (P < .01). Twenty-seven patients rated their postoperative result as excellent or good. Most positive preoperative lift-off and belly-press tests were reversed by surgery, with a rate of 6 (20%) persistent positive tests after surgery. Positive postoperative subscapularis tests were more likely related to a higher preoperative degree of fatty subscapularis muscle infiltration (P < .05). Ultrasound and magnetic resonance imaging revealed a structural intact repair at follow-up in 28 shoulders (93%). Seventy-five percent of athletes returned to their previous competition level.

CONCLUSION

Early repair of isolated traumatic subscapularis tendon tears and associated biceps tendon lesions or HAGL lesions achieves good functional outcomes with a low re-rupture rate and allows return to sports activity. Delay of surgery and higher degrees of preoperative fatty infiltration of the subscapularis muscle impair postoperative subscapularis function.

Subscapularis management in open shoulder surgery

Management of the subscapularis in open shoulder surgery is a controversial topic. Subscapularis tenotomy has been the traditional approach, but other techniques have recently been developed to preserve the integrity of the subscapularis tendon. These include subscapularis peel, subscapularis split, and lesser tuberosity osteotomy. The biologic healing and biomechanical properties associated with each surgical approach must be evaluated to determine the best option for each patient. A strong, anatomic repair is required to achieve optimal clinical outcomes.

Subscapularis tendon tears: identifying mid to distal footprint disruptions

We present an arthroscopic technique used to identify mid to distal subscapularis tendon disruptions. These tears can be easy to miss and require a thorough arthroscopic evaluation of the medial biceps sling and the medial side wall of the bicipital groove to detect. The arthroscopic procedure is performed with the patient in the lateral decubitus position, and the same portals used for standard subscapularis repair are used for this technique. If a high degree of clinical suspicion exists for subscapularis pathology and no tendon disruption is initially identified, an inspection of the medial biceps sling and medial side wall of the bicipital groove may show mid to distal subscapularis tendon disruptions. A 70 degrees arthroscope is essential in visualizing the medial sling, the subscapularis tendon, the biceps tendon, and the proximal 2 cm of the bicipital groove. Any disruptions or rents in the medial sling or medial side wall are suggestive of a subscapularis tear. Once a tear is identified, we proceed with a biceps tenodesis and then take down the medial sling from the lesser tuberosity to better delineate the subscapularis footprint. The subscapularis may then be repaired in standard fashion.

Arthroscopic visualization of subscapularis tendon lesions

Certain lesions of the subscapularis tendon are difficult to identify during routine shoulder arthroscopy due to the fact that complete visualization of the tendon's insertion on the lesser tuberosity can be challenging. This article describes a maneuver used during shoulder arthroscopy that provides excellent visualization of the subscapularis tendon insertion on the proximal humerus. This technique is advantageous because (1) it allows for complete visualization of the intra-articular tendinous insertion of the subscapularis using a standard 30 degrees arthroscope inserted through the standard posterior portal and (2) it facilitates the use of standard transrotator interval portals for tendon debridement, suture passage, or implant insertion without the need for accessory portals.

Lesão isolada do tendão do subescapular

OBJETIVOS: Analisar os resultados do tratamento cirúrgico de pacientes com lesão isolada do tendão do músculo subescapular. PACIENTES E MÉTODOS: Foram avaliados 12 pacientes com lesão isolada do tendão do músculo subescapular submetidos a tratamento cirúrgico entre junho de 1987 a abril de 2005. Em 10 pacientes a lesão era de origem traumática. Oito eram do sexo masculino e quatro do feminino. O tempo de dor no período pré-operatório variou de três dias até 72 meses. Sete pacientes foram submetidos a tratamento artroscópico e cinco por cirurgia aberta. Sete possuíam lesão completa do tendão e cinco lesões parciais. RESULTADOS: A mobilidade no período pós-operatório dos pacientes passou de elevação média de 135º para 150º, a rotação lateral média de 60º para 50º e a rotação medial passou de média de T12 para T9. Os seis pacientes que praticavam esportes, retornaram ao nível de atividade prévio. Pelo método da UCLA, 11 pacientes tiveram resultados excelentes e bons. Houve associação de 33,3% de lesão do tendão da cabeça longa do bíceps braquial. CONCLUSÃO: O tratamento cirúrgico da lesão isolada do tendão subescapular propicia bons resultados e satisfação na parte dos pacientes.

The spiral glenohumeral ligament: an open and arthroscopic anatomy study

PURPOSE

The purpose of this study was to visualize arthroscopically and to describe the micro- and macroscopic anatomy of the poorly known ligament of the anterior capsule of the glenohumeral joint: the so-called ligamentum glenohumerale spirale (spiral GHL).

METHODS

Twenty-two fresh shoulder joints were dissected, and the anatomy of the anterior capsular structures (the spiral GHL, the middle glenohumeral ligament [MGHL], and the anterior band as well as the axillary part of the inferior glenohumeral ligament [AIGHL and AxIGHL, respectively]) was investigated. For arthroscopic visualization, 30 prospective arthroscopic clinical cases and 19 retrospective video clips of the patients who had an arthroscopic shoulder procedure with a normal subscapularis tendon, labrum, and anterior joint capsule were evaluated.

RESULTS

The spiral GHL and the AxIGHL were present in all 22 shoulder specimens. The AIGHL was not recognizable on the extra-articular side of the joint capsule. The MGHL was absent in 3 shoulder specimens (13.6%). Arthroscopically, the spiral GHL was found in 22 (44.9%), the MGHL in 43 (87.8%), and the AIGHL in 46 (93.9%) of the cases. The spiral GHL arose from the infraglenoid tubercle and the triceps tendon and inserted together with subscapularis tendon onto the lesser tubercle of the humerus.

CONCLUSIONS

Our results suggest that extra-articular structure of the spiral GHL is consistently recognizable, the upper part of which can be arthroscopically identified.

CLINICAL RELEVANCE

Advanced anatomic knowledge of the spiral GHL helps the clinician better understand the normal anatomy of the shoulder joint and also helps to differentiate it from pathologic findings of the patient. The biomechanical importance of the spiral GHL and its connection with shoulder pathology remains to be determined in further studies.

Subscapularis tendon tear: an anatomic and clinical investigation

PURPOSE

The purpose of this study was to clarify anatomically and clinically how the subscapularis tendon supports the superior portion of the biceps tendon to the intertubercular groove.

METHODS

Thirty-three embalmed shoulder girdles were examined to investigate the subscapularis tendon and the pathway of the biceps tendon. In addition, operation records of 435 consecutive arthroscopic rotator cuff repairs were retrospectively reviewed.

RESULTS

Anatomically, the superior-most insertion of the subscapularis tendon was located on the upper margin of the lesser tuberosity. In addition, a thin tendinous slip extended from the insertion and attached to the fovea capitis of the humerus. The insertion, the tendinous slip, and the lateral portion of the cranial part of intramuscular tendons were in direct contact with the inferior side of the biceps tendon at its corner portion. The clinical study showed that 27.4% of rotator cuff tears (119/435) had subscapularis tendon tears. In cases with an unstable biceps tendon there was no intact subscapularis tendon. The superior-most insertion of the subscapularis tendon was involved in all transverse tears. Of 29 full-thickness transverse tears, 13 (44.8%) showed intra-articular dislocation.

CONCLUSIONS

The trochlea-like structure was composed of the superior-most insertion, the tendinous slip, and the lateral portion of the cranial part of intramuscular tendons supporting the biceps tendon. The transverse tear of the subscapularis tendon, which included this trochlea-like structure, often leads to intra-articular dislocation of the biceps tendon.

CLINICAL RELEVANCE

Instability of the biceps tendon should be carefully assessed because it is associated with subscapularis tendon tears at a very high incidence. When we repair a transverse tear of the subscapularis tendon, we should widely fix sufficiently strong tissue to support the biceps tendon on the uppermost margin, not on the anteromedial portion, of the lesser tuberosity.

Arthroscopic treatment of calcifying tendonitis of subscapularis and supraspinatus tendon: a case report

Reports concerning the surgical treatment of calcifying tendinits of the subscapularis tendon are rare. We present the case of a symptomatic calcifying tendonitis involving the subscapularis and supraspinatus tendons. The patient was treated with an arthroscopic removal of the calcific deposits. One year after the surgical procedure the patient was completely pain free, had full range-of-motion and negative supraspinatus and subscapularis signs on manual muscle testing. The overall constant score was 93 points. Radiographic evaluation revealed a complete removal of the calcific deposits immediately after the procedure without recurrence after 1 year. We conclude that a combined arthroscopic removal of the calcific deposits of the subscapularis and supraspinatus tendons can lead to an excellent clinical outcome without compromising the functional integrity of the rotator cuff tendons.

Die isolierte Subskapularissehnenruptur

Isolated subscapularis tendon tears are rare and often of traumatic origin. Despite specific clinical tests and exact radiological tools (ultrasound, magnetic resonance imaging), these tendon ruptures are often overlooked. For restoration of normal biomechanical joint function, immediate operative reconstruction is recommended. Tears of the upper subscapularis and partial articular-side tendon can be safely managed arthroscopically. The biceps tendon is often involved, and adequate treatment with tenotomy or tenodesis must be given to prevent postoperative pain. Complete subscapularis tendon avulsions should be reconstructed with an open repair technique. Immediate surgical management provides better results than delayed repair.