Single-tendon tears of the rotator cuff. Evaluation and treatment of subscapularis tears and principles of treatment for supraspinatus tears

Subscapularis Insufficiency: What’s All the Fuss About?

There has been increase attention to the surgical treatment of the subscapularis (SSC) tendon with risk of postoperative dysfunction and early failures following shoulder arthroplasty. Studies investigating the clinical results after shoulder arthroplasty indicate that SSC tendon detachment or incision techniques and rehabilitation concepts may impair SSC recovery and consequently the postoperative function. In response to these results, technical modifications have been proposed and evaluated anatomically, biomechanically, and clinically. The aim of this article is to give an overview of current SSC take-down approaches, subsequent repair techniques, and postoperative rehabilitation protocols as well as to present the diagnostic algorithm and clinical impacts of the increasingly acknowledged condition of SSC insufficiency following shoulder arthroplasty procedures.

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.

Optimal Lateral Row Anchor Positioning in Posterior-Superior Transosseous Equivalent Rotator Cuff Repair: A Micro-Computed Tomography Study

Background:

The optimal placement of suture anchors in transosseous-equivalent (TOE) double-row rotator cuff repair remains controversial.

Purpose:

A 3-dimensional (3D) high-resolution micro–computed tomography (micro-CT) histomorphometric analysis of cadaveric proximal humeral greater tuberosities (GTs) was performed to guide optimal positioning of lateral row anchors in posterior-superior (infraspinatus and supraspinatus) TOE rotator cuff repair.

Study Design:

Descriptive laboratory study.

Methods:

Thirteen fresh-frozen human cadaveric proximal humeri underwent micro-CT analysis. The histomorphometric parameters analyzed in the standardized volumes of interest included cortical thickness, bone volume, and trabecular properties.

Results:

Analysis of the cortical thickness of the lateral rows demonstrated that the entire inferior-most lateral row, 15 to 21 mm from the summit of the GT, had the thickest cortical bone (mean, 0.79 mm; P = .0001), with the anterior-most part of the GT, 15 to 21 mm below its summit, having the greatest cortical thickness of 1.02 mm (P = .008). There was a significantly greater bone volume (BV; posterior, 74.5 ± 27.4 mm³; middle, 55.8 ± 24.9 mm³; anterior, 56.9 ± 20.7 mm³; P = .001) and BV as a percentage of total tissue volume (BV/TV; posterior, 7.3% ± 2.7%, middle, 5.5% ± 2.4%; anterior, 5.6% ± 2.0%; P = .001) in the posterior third of the GT than in intermediate or anterior thirds. In terms of both BV and BV/TV, the juxta-articular medial row had the greatest value (BV, 87.3 ± 25.1 mm³; BV/TV, 8.6% ± 2.5%; P = .0001 for both) followed by the inferior-most lateral row 15 to 21 mm from the summit of the GT (BV, 62.0 ± 22.7 mm³; BV/TV, 6.1% ± 2.2%; P = .0001 for both). The juxta-articular medial row had the greatest value for both trabecular number (0.3 ± 0.06 mm^–1; P = .0001) and thickness (0.3 ± 0.08 μm; P = .0001) with the lowest degree of trabecular separation (1.3 ± 0.4 μm; P = .0001). The structure model index (SMI) has been shown to strongly correlate with bone strength, and this was greatest at the inferior-most lateral row 15 to 21 mm from the summit of the GT (2.9 ± 0.9; P = .0001).

Conclusion:

The inferior-most lateral row, 15 to 21 mm from the tip of the GT, has good bone stock, the greatest cortical thickness, and the best SMI for lateral row anchor placement. The anterior-most part of the GT 15 to 21 mm below its summit had the greatest cortical thickness of all zones. The posterior third of the GT also has good bone stock parameters, second only to the medial row. The best site for lateral row cortical anchor placement is 15 to 21 mm below the summit of the GT.

Clinical Relevance:

Optimal lateral anchor positioning is 15 to 21 mm below the summit of the greater tuberosity in TOE.

Outcome of arthroscopic subscapularis tendon repair: Are the results improving with improved techniques and equipment?: A retrospective case series

BACKGROUND

Rotator cuff tears are a common cause of shoulder pain and dysfunction. More recently, there has been a renewed interest in understanding the subscapularis tears. There are multiple articles in the literature showing the short term results of isolated subscapularis tendon repair. However, the midterm and long term outcome studies for arthroscopic subscapularis repair are few. This study evaluates the functional outcome after arthroscopic subscapularis repair.

MATERIALS AND METHODS

The records of 35 patients who underwent an arthroscopic subscapularis repair between May 2008 and June 2012 were included in this retrospective study. The records of all patients were reviewed. There were 22 males and 13 female patients with mean age of 58.2 years (range 41-72 years). All patients had a complete history, physical examination, and radiographs of their shoulders. Visual analogue scale (VAS), range of movements, power of cuff muscles, and modified University of California at Los Angeles (UCLA) score were assessed.

RESULTS

The mean followup was 2.8 years (range 2-4 year). Functional outcome after arthroscopic subscapularis repair has an excellent outcome as analysed by clinical outcome, VAS score and UCLA score. Results were analyzed and had statistically significant values. The VAS for pain improved significantly (P < 0.001), and the mean modified UCLA score improved significantly (P < 0.001) from 14.24 ± 4.72 preoperatively to 33.15 ± 2.29 at 2 years postoperative. According to the UCLA system, there were 22 excellent, 11 good, and 2 fair results. Around 95% of patients returned to their usual work after surgery.

CONCLUSION

At a median followup of 2 years, 95% of patients had a good to excellent result after an arthroscopic subscapularis tendon repair. We conclude that the midterm results show that arthroscopic subscapularis repair remains a good option for the treatment of patients with subscapularis tendon repair.

In vivo microstructural analysis of the humeral greater tuberosity in patients with rotator cuff tears using multidetector row computed tomography

BACKGROUND

In arthroscopic surgery, the suture anchor technique has become popular for rotator cuff repair. Preoperative evaluation of the bone microstructure is of utmost importance because, especially in elderly patients, osteoporotic changes may cause anchor pullout, which results in failure of rotator cuff repair. Many groups have reported humeral microstructural analysis; however, most studies were experiments using porcine specimens or human cadavers. In this study, we used multidetector row computed tomography to successfully perform in vivo evaluation of the bone microstructure of the humeral greater tuberosity in patients with rotator cuff tears.

METHODS

Ten patients were examined. Regions of interest were defined in six quadrants of the greater tuberosity (medial, lateral, and far lateral rows of the anterior and posterior areas). The local bone mineral density and the trabecular microstructural parameters, including the mean bone volume to total volume (BV/TV), trabecular thickness, trabecular separation, and structure model index (SMI), were measured using bone analysis software.

RESULTS

The BV/TV of the posteromedial region was highest and the SMI of the posteromedial region was lowest. These findings suggest that the bone quality of the posteromedial portion is the highest within the greater tuberosity.

CONCLUSION

Because the bone quality may be correlated with the pullout strength of suture anchors, our method can help to understand the individual and regional variance in bone quality and may lead to the creation of personalized surgical protocols.

A systematic approach for diagnosing subscapularis tendon tears with preoperative magnetic resonance imaging scans

PURPOSE

To determine and propose a systematic approach to evaluating magnetic resonance imaging (MRI) scans for subscapularis tears and compares preoperative MRI interpretations with findings of the same shoulders at arthroscopy.

METHODS

The study was composed of 202 patients who underwent shoulder arthroscopy by 1 of 5 orthopaedic surgeons during a 3-month period. All patients had MRI scans performed within 6 months before arthroscopy.

RESULTS

Of the 202 patients, 82 had subscapularis tendon tears confirmed at the time of arthroscopy. The orthopaedic surgeons correctly diagnosed 60 of 82 patients (73%) with subscapularis tendon tears on preoperative MRI that were subsequently identified by arthroscopy. The orthopaedic surgeons correctly diagnosed 113 of 120 patients (94%) as not having subscapularis tendon tears. This resulted in an overall sensitivity of 73%, specificity of 94%, positive predictive value of 90%, negative predictive value of 84%, and accuracy of 86%. The frequency of subscapularis tears was highest when the long head of the biceps was displaced from the groove (88%), a combined supraspinatus/infraspinatus tear existed (71%), or the long head of the biceps tendon was torn (69%).

CONCLUSIONS

Preoperative MRI scans of the shoulder interpreted by orthopaedic surgeons with the described systematic approach resulted in improved accuracy in diagnosing subscapularis tendon tears compared with previous studies. A consistent finding is that larger subscapularis tendon tears are more easily detected using MRI scans whereas smaller tears are more frequently missed.

LEVEL OF EVIDENCE

Level III, development of diagnostic criteria with universally applied reference (nonconsecutive patients).

Why repair the subscapularis? A logical rationale

Tears of the subscapularis tendon are now more frequently recognized and are often associated with tears of the posterosuperior rotator cuff tendons. This has been facilitated by arthroscopic approaches, and repair techniques have been developed. In the setting of a rotator cuff repair, when a subscapularis tendon tear is found in continuity with a supraspinatus tendon tear, it is essential to recognize how the repair of both tendon tears can influence the overall security of the entire repair construct. When a repairable subscapularis tendon tear is left unrepaired, the function of the subscapularis muscle will be lost. In addition, the posterosuperior rotator cuff tear will be more difficult to repair, and it will be less securely repaired. When the subscapularis tendon is repaired initially, the posterosuperior rotator cuff repair can be more easily and more reliable achieved.

Subscapularis tendon integrity: an examination of shoulder index tests

CLINICAL QUESTION

The systematic review focused on various index tests for the shoulder. We concentrated on the subscapularis tendon results to determine the accuracy of reported index tests for clinically diagnosing subscapularis integrity.

DATA SOURCES

Studies were identified by an OVID search using MEDLINE, SPORTDiscus, and CINHAL databases (1966-2006) and a hand search by 2 authors (E.J.H. and S.C.). Primary search terms were shoulder, examination, and diagnosis. In addition to the database searches, personal files were hand searched by one of the authors (E.J.H.) for publications, posters, and abstracts. The reference lists in review articles were cross-checked, and all individual names of each special test were queried using MEDLINE and PubMed.

STUDY SELECTION

The search was limited to English-language journals. Studies were eligible for inclusion if the criterion standard was surgery, magnetic resonance imaging, or injection (subacromial or acromioclavicular joint); at least 1 physical examination test or special test was studied; and one of the paired statistics of sensitivity and specificity was reported or could be determined. Excluded were studies in which the index test was performed under anesthesia or in cadavers, studies in which the index test was assigned the status of composite physical examination, and review articles. Studies were grouped according to the subscapularis index test assessed: lift off, internal-rotation lag sign, Napoleon sign, bear hug, belly off, and belly press.

DATA EXTRACTION

Studies were selected in a 2-stage process. First, all abstracts and articles found through the search process were independently reviewed by 2 authors (E.J.H. and S.C.). Disagreement on inclusion of an article was resolved by consensus. Second, each selected study was assessed by each reviewer independently. A third reviewer made the final decision on any disagreements for the selected studies. The primary outcome measures were sensitivity and specificity and positive and negative likelihood ratios. The quality of a study was determined by assessing its internal and external validity. Validity was determined by the primary author (E.J.H.) using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) statement. Our work required data extraction from the original articles, which we used to generate 2 x 2 contingency tables for each index test. Pooled indices of clinical usefulness were then determined for each index test.

MAIN RESULTS

The specific search criteria identified 922 articles for review. Of these, 4 met the inclusion and exclusion criteria for subscapularis tendon tears, resulting in the number of studies assessing each index test as follows: 4 for lift off, 2 for internal-rotation lag sign, 2 for Napoleon sign, 1 for bear hug, 1 for belly off, and 1 for belly press. Subscapularis tears were identified by the criterion standard of surgery to visually assess the torn fibers. Across all 4 studies, a total of 304 shoulders were examined, 95 of which had a subscapularis tear (45 full thickness, 50 partial thickness), and 106 were injury free. Indices of clinical usefulness for full-thickness and partial-thickness subscapularis tears are reported in Tables 1 and 2 , respectively.

Pectoralis major transfer for the treatment of irreparable anterosuperior rotator cuff tears

The purpose of this study was to evaluate the outcome of subcoracoid pectoralis major transfer for the treatment of irreparable anterosuperior rotator cuff tears. This type of tear involves complete rupture of the subscapularis in combination with either the supraspinatus alone or the supraspinatus and infraspinatus. These ruptures are characterised by a poor quality of the rotator cuff that does not allow for a direct tendon-to-bone reconstruction. Between 2000 and 2006, 15 patients were treated using a deltopectoral approach and transfer of the clavicular part of the pectoralis major to the lesser tuberosity and to the anterior part of the greater tuberosity. After an average follow-up (follow-up rate 100%) of 37 months the average functional rating using the Constant and Murley score (CS) increased from 51.73 +/- 16.18 to 68.17 +/- 8.84 points (p = 0.005). The mean subcategories of the Constant score for pain (p = 0.005), activities of daily living (p = 0.008) but not for range of motion (p = 0.9), significantly improved. At follow-up 13 patients (87%) were available for magnetic resonance imaging (MRI) of the shoulder. Nine patients (70%) had an intact transferred pectoralis major muscle, two (15%) had one that was thin but intact and two patients a rupture (one complete). Two patients had postoperative haematoma and one patient developed cuff tear arthropathy. The good results confirm that pectoralis major transfer is a reliable treatment option for irreparable anterosuperior rotator cuff injuries with significant improvement in pain and function.

The results of arthroscopic subscapularis tendon repairs

PURPOSE

The purpose of this study was to evaluate patients after an arthroscopic subscapularis tendon repair to determine their intermediate-term results.

METHODS

The records of all patients who underwent an arthroscopic rotator cuff repair by the senior author (S.S.B.) between January 1, 2000, and December 31, 2003, were reviewed. Patients were excluded from the study if their rotator cuff was repaired but there was not a subscapularis tear. Forty patients were included in this study. The median follow-up from the date of surgery to the last clinical evaluation was 5.0 years (range, 3.2 to 7.1 years). All patients had a complete history, physical examination, and plain radiographs of their shoulders. Both the modified University of California at Los Angeles (UCLA) and American Shoulder and Elbow Society (ASES) scores were calculated.

RESULTS

The visual analog scale for pain (mean +/- standard deviation) improved significantly (P < .001) from 6.1 +/- 2.4 preoperatively to 0.9 +/- 1.4 at the latest clinical follow-up evaluation; similarly, the mean modified ASES score improved significantly (P < .001) from 40.5 +/- 15.7 preoperatively to 91.2 +/- 12.7, and the mean modified UCLA score improved significantly (P < .001) from 15.7 +/- 4.2 preoperatively to 31.6 +/- 4.8. According to the UCLA scoring system, there were 18 excellent, 14 good, 6 fair, and 2 poor results. Eighty-three percent of patients returned to their usual work, sport, or hobbies after the operation.

CONCLUSIONS

At a median follow-up of 5 years, 80% (32 of 40) of patients had a good or excellent result after an arthroscopic subscapularis tendon repair. Eighty-eight percent of patients were satisfied with their shoulders at the latest follow-up evaluation. We conclude that the intermediate-term results show that arthroscopic subscapularis tendon repairs remain a good option for the treatment of patients with subscapularis tendon tears.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Traumatic anterosuperior rotator cuff tears: the outcome of open surgical repair

BACKGROUND

Anterosuperior rotator cuff tears involving the subscapularis and supraspinatus tendons are less common than posterosuperior tears and are rarely discussed in the literature. The purpose of this study was to identify the unique features of this injury and to assess the outcome of operative treatment.

METHODS

Thirty consecutive patients, with a mean age of fifty-seven years (range, forty-three to seventy-three years), had an open repair of a traumatic anterosuperior rotator cuff tear. Twenty-four patients (80%) were male. Sixteen patients (53%) had involvement of the dominant shoulder, twenty-three (77%) had a biceps tendon disorder, and sixteen (53%) had a positive lift-off maneuver prior to surgery. Surgical approaches included an isolated superior deltoid-splitting approach in twenty patients, an isolated deltopectoral approach in five patients, and a combined approach in five patients. Open repair was performed at a mean of 4.5 months after the injury or the onset of symptoms. The final outcomes were determined with a physical examination and patient self-assessed outcome tools.

RESULTS

At a mean follow-up of fifty-six months, twenty-one of the thirty patients were satisfied with their symptoms, and twenty-nine would have the surgery again. The mean pain score on the visual analog scale improved from 6.2 to 1.2 (p < 0.001). The mean score on the Disabilities of the Arm, Shoulder and Hand questionnaire improved from 41.7 to 12.2 (p < 0.001). The mean percentage of functions that patients were able to perform on the Simple Shoulder Test improved from 36.4% to 82.8% (p < 0.001). The mean age and sex-adjusted Constant score was 93.4 postoperatively. The mean elevation, external rotation, and internal rotation of the involved shoulders were 97%, 109%, and 97%, respectively, of those of the contralateral side. The mean strength of elevation, external rotation, and internal rotation were 85%, 93%, and 101%, respectively, of those of the contralateral side. Infraspinatus involvement (p = 0.04), the extent of the supraspinatus tear (p = 0.03), and a Workers' Compensation claim (p = 0.03) were associated with worse outcomes and decreased satisfaction.

CONCLUSIONS

Patients with a traumatic anterosuperior rotator cuff tear present with internal rotation weakness, and they usually have a biceps tendon disorder. While larger tears involving greater portions of the supraspinatus and extending into the infraspinatus are associated with poorer outcomes, early recognition of this injury and open repair can reliably restore shoulder function to near normal levels.

Subscapularis dysfunction following anterior surgical approaches to the shoulder

Subscapularis dysfunction following open surgical exposure of the glenohumeral joint has recently received attention. Clinical studies, in particular those that have investigated the results after open shoulder stabilization or shoulder replacement surgery, indicate that anterior approaches using different subscapularis tendon take-down or incision techniques may impair subscapularis recovery and can negatively influence the final clinical outcome. This review article will focus on the potential pathogenesis, diagnosis, and clinical impact of this more and more recognized condition and summarizes the currently available literature.

The subscapularis footprint: an anatomic description of its insertion site

PURPOSE

The purpose of this study was to describe the anatomic footprint of the subscapularis tendon.

METHODS

We examined 19 cadaveric shoulder specimens in this study. Dissection was carried out to the level of the subscapularis through a deltopectoral approach. The subscapularis tendon was identified, and the dissection was continued, elevating the tendon, subperiosteally, from its insertion site at the lesser tuberosity. The dimensions of the footprint were measured superior to inferior, as well as medial to lateral, by a single observer.

RESULTS

The insertion of the subscapularis tendon on the lesser tuberosity was trapezoidal in shape. The mean length of the subscapularis tendon footprint was 2.5 cm (range, 1.5 to 3.0 cm). The superior portion of the footprint was the widest part of the subscapularis insertion. The mean width at the most superior aspect of the insertion site was 1.8 cm (range, 1.5 to 2.6 cm). The most inferior aspect of the footprint was much narrower, with a mean width of 0.3 cm (range, 0.1 to 0.7 cm).

CONCLUSIONS

The subscapularis insertion footprint has a broad and wide superior attachment that narrows distally to form a trapezoidal shape. We found the mean length of the footprint to be 2.5 cm. The mean superior width of the footprint was 1.8 cm, which was maintained for the upper 60% of the tendon insertion, at which point the footprint began to rapidly narrow to a minimum width of 0.3 cm at its most inferior aspect. The upper 60% of the footprint provided by far the major surface area for tendon insertion, consistent with prior findings of superior load transmission at the superior aspect of the footprint.

CLINICAL RELEVANCE

This broad attachment site superiorly is likely important in load transmission. Knowledge of the shape of the footprint of the subscapularis, with a broad superior attachment, makes it easier for the surgeon to perform an accurate anatomic surgical reconstruction of the torn subscapularis.

The subscapularis footprint: an anatomic study of the subscapularis tendon insertion

PURPOSE

Arthroscopic repair of the subscapularis tendon has become more prevalent in recent years. Tears of the subscapularis insertion can be measured arthroscopically when the size of the average subscapularis tendon insertion is known. This anatomic study was performed to measure the dimensions and describe the anatomy of the subscapularis footprint.

METHODS

A total of 6 male and 6 female shoulders were dissected down to the insertion of the subscapularis tendon. The insertion was demarcated, the tendon was detached, and the dimensions of the insertion site were measured.

RESULTS

The footprint is the insertion of the subscapularis tendon onto the lesser tubercle. The shape of the footprint was characterized as resembling a human ear. The insertion is broad proximally and tapered distally and has a straight medial border that is almost parallel to the longitudinal axis of the humerus. The total average cephalocaudal height of the footprint was 25.8 mm (+/-3.2 mm). The total average width was 18.1 mm (+/-1.6 mm). Average male cephalocaudal height was 26.7 mm (range, 22 to 32 mm), and width was 18.3 mm (range, 16 to 21 mm). Average female cephalocaudal height was 24.8 mm (range, 22 to 29 mm), and width was 17.8 mm (range, 15 to 19 mm). Although the male footprint was slightly larger than the female footprint, differences were not statistically significant (P = .18 and .31 for height and width, respectively).

CONCLUSIONS

An anatomic study was performed to determine the size of the footprint of the subscapularis tendon. We found that the average cephalocaudal height of the footprint was 25.8 mm, and the average width was 18.1 mm.

CLINICAL RELEVANCE

Subscapularis tears are now more frequently addressed arthroscopically. This anatomic study was performed to characterize the anatomy of the subscapularis footprint so that the surgeon can achieve a more anatomic repair.

Isolated and combined tears of the subscapularis tendon

BACKGROUND

Isolated and combined subscapularis tendon tears are rare and are described in the literature only in small numbers.

HYPOTHESIS

The outcome of surgical intervention for isolated and combined subscapularis tendon tears may be influenced by the tear pattern of the anterior rotator cuff and the period of time between trauma and surgical procedure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 1994 and 1999, 34 shoulders with isolated traumatic tears (16 shoulders) or subscapularis tendon rupture combined with a supraspinatus tendon tear were treated operatively. The average patient age was 51 years, and the mean follow-up period was 37 months. For statistical analyses, the Friedman and Mann-Whitney tests were used.

RESULTS

In patients with isolated tears, the Constant score rose from an average of 43.9 to 88.7 points (P < .01), and in patients with combined tears, it rose from an average of 40.6 to 74.7 points (P <.01). Isolated tears improved 14 points more than combined tears (P <.05). The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was -0.97 in isolated tears and -0.89 in combined tears.

CONCLUSIONS

Young patients with isolated traumatic tears of the subscapularis tendon and immediate repair have the best prognostic factors for treatment. Accuracy in the trauma history and the clinical and radiographic examination is demanded.

Relation between narrowed coracohumeral distance and subscapularis tears

PURPOSE

To determine whether coracohumeral distance was significantly narrowed in the presence of a torn subscapularis.

TYPE OF STUDY

Retrospective cohort study.

METHODS

The coracohumeral distance of a consecutive series of patients (n = 35, 36 shoulders) requiring an arthroscopic repair of the subscapularis was compared with a control group (n = 35). The control group consisted of patients who underwent shoulder arthroscopy but who did not have any rotator cuff, subscapularis, or subcoracoid pathology. The coracohumeral distance was measured from the tip of the coracoid to the cortex of the proximal humerus on an axial cut of preoperative magnetic resonance imaging. A Student t test was used to determine the statistical differences between the 2 groups.

RESULTS

The average coracohumeral distance in the subscapularis group was 5.0 +/- 1.7 mm and the average coracohumeral distance in the control group was 10.0 +/- 1.3 mm. Statistical analysis, using the Student t test, showed that the coracohumeral distance was significantly narrowed in the group of patients with a torn subscapularis.

CONCLUSIONS

These results show a significant relationship between a narrowed coracohumeral distance and subscapularis pathology.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Subscapularis tendon tears

Pathology of the subscapularis tendon is both infrequently identified and not commonly considered as a major source of shoulder pain and dysfunction. Subscapularis tendon pathology can present as isolated tears; partial-thickness tears; anterosuperior tears, also involving the supraspinatus tendon; complete rotator cuff avulsion; and rotator interval lesions, in which instability of the long head of the biceps tendon may dominate the clinical presentation. Although an accurate physical examination is paramount, modalities such as arthroscopy, magnetic resonance imaging, and ultrasound have advanced knowledge of the spectrum of abnormalities involving the subscapularis tendon. Nonsurgical management may be effective for most partial tears. Surgically, open repair is more frequent than use of arthroscopic techniques. Tears of the subscapularis tendon portend a different prognosis than do supraspinatus tendon tears, especially when the injury is acute and diagnosis is delayed.

Comparison of total and partial traumatic tears of the subscapularis tendon

We treated surgically 16 shoulders with an isolated traumatic rupture of the subscapularis tendon over a six-year period. Nine patients had a total and seven a partial tear of the subscapularis tendon. Repair was undertaken through a small deltopectoral groove approach. The mean Constant score improved in total tears from 38.7 to 89.3 points (p = 0.003) and in partial tears from 50.7 to 87.9 points (p = 0.008). The total tears were significantly more improved by surgery than the partial tears (p = 0.001). The delay between trauma and surgery was inversely proportional to the improvement in the Constant score suggesting that early diagnosis and surgical repair improves outcome.

Open operative treatment for anterior shoulder instability: when and why?

The treatment of anterior glenohumeral instability continues to evolve. Open capsulolabral repairs are time-tested and reliable. In an era in which arthroscopic techniques continue to improve, open surgery remains an acceptable option, and there are still certain injury patterns that cannot be adequately addressed arthroscopically. Decision-making regarding surgery for instability is influenced by the surgeon's experience and the relevant pathological findings. Open operative treatment is the preferred approach in many instances of recurrent anterior instability, particularly when there is bone and soft-tissue loss and in revision settings.

Anchor design and bone mineral density affect the pull-out strength of suture anchors in rotator cuff repair: which anchors are best to use in patients with low bone quality?

BACKGROUND

Different metal and biodegradable suture anchors are available for rotator cuff repair. Poor bone quality may result in anchor loosening and tendon rerupture.

HYPOTHESES

Higher bone mineral density is associated with higher pull-out strength of suture anchors. Depending on anchor placement, pull-out strengths of anchors are different within the greater tuberosity.

STUDY DESIGN

Cadaveric biomechanical study.

METHODS

Trabecular and cortical bone mineral densities were determined for different regions within the greater tuberosity. Metal screw-type and biodegradable hook-type anchors were cyclically loaded.

RESULTS

Mean failure load of metal and biodegradable anchors was 273 N and 162 N, respectively, for the proximal part (P < .01) and 184 N and 112 N, respectively, for the distal part (P < .01). Both types of anchors showed higher failure loads in the proximal-anterior and -middle parts of the greater tuberosity than in the distal part (P < .01). A significant positive correlation was found between cortical bone mineral density and failure load of metal anchors (P < .01).

CONCLUSION

Bone quality, anchor type, and anchor placement have a significant impact on anchor failure loads.

CLINICAL RELEVANCE

Suture anchors should be placed in the proximal-anterior and -middle parts of the greater tuberosity. In the distal parts, biodegradable hook-like anchors should be used with caution.

The anatomy of the subscapularis tendon insertion as applied to rotator cuff repair

The tendons constituting the rotator cuff (RC) are often torn, and several techniques for their repair have been established. The existence of an extension of the supraspinatus tendon into that of the subscapularis has often been overlooked. The purpose of this study was to study this extension in human dissections. The possible posterolateral extension of the subscapularis tendon and the interdigitating of this extension with the supraspinatus tendon were addressed. A horizontal band of tissue 1 cm below the superior ridge of the greater tuberosity of the humerus was harvested from 43 cadavers and thus included tissue constituting the greater tuberosity, bicipital groove, and lesser tuberosity. The sample extended 2 cm medially along the lesser tuberosity and 1 cm laterally along the greater tuberosity. Macroscopic findings suggest a continuous band of tissue extending across the bicipital groove. High collagen content was microscopically confirmed at different sections, and the collagen was densely distributed along the horizontal axis of the tissue samples.

The etiology and assessment of subscapularis tendon tears: a case for subcoracoid impingement, the roller-wringer effect, and TUFF lesions of the subscapularis

With the advent of arthroscopy and arthroscopic repair techniques, the diagnosis and treatment of subscapularis tears have been significantly advanced. The precise etiologic factors related to subscapularis tears remain unclear. We propose that subcoracoid stenosis and subcoracoid impingement cause a "roller-wringer effect" on the subscapularis tendon. This effect increases the tensile loads on the articular surface of the subscapularis tendon that may lead to tensile undersurface fiber failure (TUFF) of the subscapularis insertion. Collectively, these factors may in part contribute to the pathogenesis of subscapularis tears.

Pullout strength of suture anchors used in rotator cuff repair

BACKGROUND

Surgical treatment of rotator cuff tears may be complicated by osteoporosis of the proximal part of the humerus. The purpose of this study was to determine whether pullout strength of suture anchors is affected by the location of the anchor placement and by bone mineral density. We hypothesized that higher bone mineral density is associated with higher pullout strength of suture anchors.

METHODS

Peripheral quantitative computed tomography was used to measure total, trabecular, and cortical bone mineral density in different regions of the lesser and greater tuberosities in seventeen cadaveric humeri. Suture anchors were inserted into individual regions and subjected to cyclic loading. Repeated-measures analysis of variance was used to assess differences in bone mineral density and load to failure between regions of interest. Pearson correlation was used to determine the association between bone mineral density and pullout strength of suture anchors.

RESULTS

Total, trabecular, and cortical bone mineral densities were an average of 50%, 50%, and 10% higher, respectively, in the proximal part of the tuberosities compared with the distal part (p < 0.01). Within the proximal part of the greater tuberosity, trabecular bone mineral density of the posterior region and cortical bone mineral density of the middle region were, on the average, 25% and 16% higher, respectively, than the densities in the other regions (p < 0.01). Load to failure in the proximal part of the tuberosities was an average of 53% higher than that in the distal part (p < 0.01). The lesser tuberosity showed, on the average, a 32% higher load to failure than did the greater tuberosity (p < 0.01). Within the proximal part of the greater tuberosity, loads to failure in the anterior and middle regions were, on the average, 62% higher than the load to failure in the posterior region (p < 0.01). Overall positive correlations were found between bone mineral density and load to failure (0.65 </= r </= 0.74, p < 0.01).

CONCLUSIONS

We found that pullout strength of suture anchors correlates well with bone mineral density of the tuberosities. Higher loads to failure were found in regions in the proximal part of the tuberosities. Placement of anchors in these regions may prevent anchor loosening, formation of a tendon-bone gap, and failure of the rotator cuff repair.

Subscapularis tears: arthroscopic repair techniques

The subscapularis is an essential component of normal shoulder function. An intact subscapularis muscle provides the anterior moment for the transverse plane force couple. Any disruption of the subscapularis disrupts normal glenohumeral biomechanics. If this occurs the shoulder functions abnormally, leading to pain and disability. A thorough history and physical examination lead the surgeon to the diagnosis of a torn subscapularis. Radiographs and MRI are helpful in delineating the rotator cuff tear pattern and other intra-articular lesions and in determining subcoracoid stenosis. Advancements with arthroscopic techniques have enabled surgeons to deal with subscapularis tears arthroscopically. There are seven key points to arthroscopic subscapularis repair: (1) portal placement (posterior portal, anterior portal, anterolateral portal, and accessory anterolateral portal), (2) visualization of the pathology by using a 30 degree and a 70 degree arthroscope, (3) manipulating the arm into maximal internal rotation to assist in assessing the tendon's relationship to its footprint, (4) appropriate anchor placement, (5) suture passage through the tendon, (6) tying secure arthroscopic knots, and (7) appropriate rehabilitation that minimizes stress on the repair. With these principles in mind, the shoulder surgeon can address disruptions of the anterior rotator cuff by repairing the subscapularis, thus alleviating the disability associated with this overlooked and under-appreciated pathology.

Tears in the subscapularis tendon: descriptive analysis and results of surgical repair

Although not well known, lesions of the subscapularis tendon are more common than usually reported. We conducted a descriptive study of 22 patients (23 shoulders), who underwent surgical repair of subscapularis tendon tears. Mean follow-up was 73 months. The findings were compared to the results of a prospective study published by one of us (R.H.C.), who reviewed 97 other patients (105 shoulders) with a mean follow-up of 13.4 years after surgical repair of a rotator cuff tear. This comparison allowed us to identify the specific features of rotator cuff tears involving the subscapularis tendon. Subscapularis tears were more likely to be related to a shoulder injury and caused more severe functional impairment, as compared to lesions of the other tendons. Time to surgical treatment was shorter when the subscapularis was torn. Subscapularis tears required adaptation of the surgical approach and postoperative protection of external rotation for 4-6 weeks. Outcomes were less satisfactory when the subscapularis tendon was torn. However, the outcomes in both studies were correlated to tear size. The outcomes were often favorable after isolated subscapularis tendon tears and less so when other tendons were involved.

Current concepts in arthroscopic rotator cuff repair

The interest in arthroscopic rotator cuff repair has increased exponentially over the last 5 years. Although the operative technique of repair continues to evolve, there are now several studies reporting excellent results after arthroscopic repair of rotator cuff tears. In this review, we focus on new concepts and techniques related to arthroscopic rotator cuff repair that have been recently introduced.

The comma sign: An arthroscopic guide to the torn subscapularis tendon

Subscapularis tears are becoming increasingly recognized as a cause of shoulder pain and disability. However, identifying the subscapularis tendon stump is often difficult during repair of chronic, retracted subscapularis tears that are scarred to the deltoid fascia. The authors have found the "comma sign," an arc formed by a portion of the superior glenohumeral ligament/coracohumeral ligament complex, to be a useful marker of the superolateral corner of the torn subscapularis tendon.

Arthroscopic repair of isolated subscapularis tears: A prospective cohort with 2- to 4-year follow-up

PURPOSE

The goal of this study was to evaluate the outcomes of the arthroscopic repair of isolated subscapularis tears. Additionally, this study explores details of the clinical diagnosis, magnetic resonance arthrography findings, and surgical repair techniques.

TYPE OF STUDY

A prospective cohort.

METHODS

The preoperative and postoperative status of patients with isolated subscapularis tears were analyzed using the Constant Score, American Shoulder and Elbow Society Index (ASES Index), a visual analog pain scale (VAS), a single question of percent function compared with the opposite unaffected extremity, and a single question reflecting satisfaction: "Would you undergo the surgery and the postoperative rehabilitation to achieve the result you have today."

RESULTS

There was a statistically significant difference for all outcome measures from preoperative to postoperative follow-up at 2 to 4 years, except for the objective Constant Score. There were no differences based on gender. Preoperative magnetic resonance arthrography aids in the confirmation of the subscapularis tear.

CONCLUSIONS

The arthroscopic repair of the isolated subscapularis tear provides for reliable expectations of improvement in function, particularly the use of the arm behind the back, decreases in pain, decreases in biceps subluxation or instability, and the return of active normal internal rotation. Subjectively, magnetic resonance arthrography is better than magnetic resonance imaging for visualizing the subscapularis tear.

Fractures and tendon injuries of the athletic shoulder

Athletic injuries in the shoulder range from a routine strain or sprain to a potentially disabling fracture or tendon rupture. The level of sports participation plays an important role in diagnosis and treatment. The nonprofessional athlete may be more likely to sustain injuries secondary to under-training or improper technique. The professional athlete may be capable of play under much higher velocities and applied loads and, therefore, may be subject to higher energy trauma than the amateur athlete. In addition to standard treatment considerations, return to play time must also be decided. Decisions regarding definitive treatment may be modulated depending on an athlete's desire to return to his or her previous level of competition.

Arthroscopic subscapularis tendon repair: Technique and preliminary results

PURPOSE

Our objective was to evaluate the preliminary results of 25 consecutive arthroscopic subscapularis tendon repairs.

TYPE OF STUDY

Case series.

METHODS

All 25 shoulders had longer than 3 months follow-up, with an average of 10.7 months (range, 3 to 48 months). The average age was 60.7 years (range, 41 to 78 years). The average time from onset of symptoms to surgery was 18.9 months (range, 1 to 72 months). The shoulders were evaluated using a modified UCLA score, Napoleon test, lift-off test, radiographs, and magnetic resonance imaging (MRI). Indications for surgery included clinical and/or MRI evidence of a rotator cuff tear. An arthroscopic suture anchor technique devised by the senior author (S.S.B.) was used for repair.

RESULTS

UCLA scores increased from a preoperative average of 10.7 to a postoperative average of 30.5 (P <.0001). By UCLA criteria, excellent and good results were obtained in 92% of patients, with 1 fair and 1 poor result. Forward flexion increased from an average 96.3 degrees preoperatively to an average 146.1 degrees postoperatively (P =.0016). Eight of 9 patients with a positive Napoleon test had complete tears of the subscapularis. All 7 patients with a negative Napoleon test had a tear of the upper half only. The lift-off test could not be performed reliably due to pain or restricted motion in 19 of the 25 patients. Eight patients had isolated tears of the subscapularis. The remaining 17 patients had associated rotator cuff tears with an average total tear size of 5 x 8 cm. Ten patients had proximal migration of the humerus preoperatively. Eight of these 10 patients had durable reversal of proximal humeral migration following surgery. These 8 patients improved their overhead function from a preoperative "shoulder shrug" with attempted elevation of the arm to functional overhead use of the arm postoperatively.

CONCLUSIONS

(1) The senior author has been able to consistently perform arthroscopic repair of torn subscapularis tendons, with good and excellent results, in 92% of patients. (2) The Napoleon test is useful in predicting not only the presence of a subscapularis tear, but also its general size. (3) Combined tears of the subscapularis, supraspinatus, and infraspinatus tendons are frequently associated with proximal humeral migration and loss of overhead function. Arthroscopic repair of these massive tears can produce durable reversal of proximal humeral migration and restoration of overhead function.

Arthroscopic visualization of the subscapularis tendon

PURPOSE

This study was conducted to define what portion of the subscapularis tendon is visualized during standard diagnostic glenohumeral arthroscopy and to determine the distance between the inferior aspect of the visible portion of the subscapularis tendon and the axillary nerve.

TYPE OF STUDY

Anatomic (cadaveric) analysis.

METHODS

Six fresh-frozen human cadaveric shoulders were placed in a simulated lateral decubitus position with longitudinal traction and 45 degrees of shoulder abduction. Glenohumeral arthroscopy was performed on each specimen using a standard posterior portal for visualization. The 4 corners of the visible portion of the subscapularis were tagged with arthroscopic sutures. The shoulders were subsequently dissected. The surface area defined by the 4 suture tags and the surface area of the entire subscapularis tendon were calculated for each specimen. The dimensions of these areas and the distance between the inferior aspect of the visible portion of the subscapularis tendon and the axillary nerve were measured with calipers.

RESULTS

The arthroscopically tagged portion of the subscapularis tendon represented only a small percentage (26% +/- 11%) of the entire tendon. The majority of the subscapularis tendon is veiled by the middle and inferior glenohumeral ligaments. There was a significant distance between the inferior aspect of the visible portion of the subscapularis tendon and the axillary nerve (32.8 +/- 6.0 mm). The mean height of the visible portion of the tendon represented 44% of the mean overall height of the subscapularis.

CONCLUSIONS

These data suggest that arthroscopic visualization of the subscapularis is incomplete. Lesions involving the concealed portion of the subscapularis tendon may not be detected arthroscopically. The wide margin of safety between the inferior aspect of the visible portion of the subscapularis tendon and the axillary nerve is relevant to the placement of anteroinferior (trans-subscapularis) arthroscopy portals as well as to performing arthroscopic anterior capsular releases.

Technique for repair of the subscapularis tendon

Patients with sudden loss of active motion after an external rotation or hyperextension injury should be viewed with a high index of suspicion for a subscapularis tear. Exaggerated external rotation and the presence of a positive lift off or belly press test on physical examination combined with appropriate imaging studies will lead to an early diagnosis. Careful surgical repair combined with a thoughtful rehabilitation program will lessen both the length and degree of disability from this clinical entity.

Diagnosis and treatment of anterosuperior rotator cuff tears

Nineteen of 407 patients who underwent rotator cuff repair surgery over a 6-year period were found to have a tear of the subscapularis in combination with the supraspinatus and infraspinatus tendons. Nine of these patients had an unsuccessful prior surgery, which failed to recognize the extent of the subscapularis component. Surgical repair of the subscapularis tendon required a deltopectoral approach, and repair of the supraspinatus and infraspinatus components of the tear could only be accomplished through this approach in 4 patients. In the remaining 15, an extended superior approach was required to mobilize and repair the supraspinatus and infraspinatus tendons. In all cases, the biceps tendon was either torn or severely degenerated, requiring tenodesis. At a mean follow-up of 40 months (range 24 to 75 months), subjective results were excellent in 5 patients, good in 3, fair in 4, and poor in 7. The modified Constant score improved to a mean of 69% (range 23% to 130%), compared with a preoperative mean of 38% (range 23% to 100%). Physical findings positive for subscapularis insufficiency persisted in 14 of 19 patients. A significant correlation (P <.05) was found between a lower Constant score and duration of symptoms longer than 6 months as well as an appearance of severe fatty degeneration and atrophy of the subscapularis muscle on magnetic resonance imaging. We conclude that anterosuperior rotator cuff tears are an infrequent configuration that may require surgical repair through an extended approach combining deltopectoral mobilization of the subscapularis with transdeltoid mobilization of the supraspinatus and infraspinatus. Repair before 6 months of symptoms is associated with a better functional outcome and is the result of less involution of muscle and tendon tissue.