The rotator interval: anatomy, pathology, and strategies for treatment

Anterior Rotator Interval Lesion (ARIL), its association with glenoid labrum pathology in patients with anterior shoulder pain and surgical outcome of Arthroscopic Rotator Interval Closure (ARIC)

Background

Anterior rotator interval lesions (ARIL) have been associated with shoulder instability. However, a paucity of data exists on its association with labrum pathology as a source for persistent anterior shoulder pain. This study primarily aims to describe pathoanatomy of ARIL and the parameters we used that aid in the diagnosis of ARIL. Secondly, the objective is to describe and report the prevalence of ARIL in combination with labrum injuries presenting as anterior shoulder pain with mild or no instability. Lastly, we intend to present a cohort of patients with combined labrum injury and ARIL and report on the clinical results after labrum repair with Arthroscopic Rotator Interval Closure (ARIC).

Methods

Consecutive patients at a single center in United States treated for labrum tears were included by retrospective chart-review. Patients presenting with anterior shoulder pain with mild or no instability were included. Patients with recurrent dislocations, moderate to severe instability and those with bony lesions were excluded. Besides history and physical examination, Magnetic Resonance Arthrography (MRA) was used to aid the diagnosis. Labrum tears with ARIL were treated with an additional ARIC procedure along with arthroscopic labrum repair.

Results

Out of two hundred fourty patients with a labrum tear, 114 had associated ARIL. The prevalence of ARIL ranged from 71 % with reverse Bankart tears to 46 % with anterior Bankart and 36 % in Type II SLAP tears. The success rate after labrum tear repair with ARIC performed in patients with ARIL with labrum pathology was 94.7 % at a 2-year follow-up in terms of relief from anterior shoulder pain.

Conclusion

Almost half (47.5 %) of our patients presented with anterior shoulder pain with labrum tears were associated with ARIL. We recommend keeping a high index of suspicion for ARIL in labrum injuries presenting mainly with anterior shoulder pain for better treatment planning.

Level of evidence

Level IV (Retrospective case series without a comparision group).

Ultrasound-guided hydrodistension for adhesive capsulitis: a longitudinal study on the effect of diabetes on treatment outcomes

OBJECTIVE

The effect of diabetes on adhesive capsulitis (AC) and its impact on the outcomes of ultrasound (US)-guided hydrodistension of the glenohumeral joint are still unclear. We aimed to identify predictors of US-guided hydrodistension outcomes, while assessing the performance of the method in diabetic compared to non-diabetic patients.

MATERIALS AND METHODS

A total of 135 patients with AC who underwent US-guided hydrodistension were prospectively included. Demographics and factors linked to chronic inflammation and diabetes were recorded and patients were followed-up for 6 months. Functionality and pain were evaluated with the Disabilities of the Arm, Shoulder and Hand (DASH) and the Visual Analogue Scale (VAS) score. Statistical analysis was performed with Mann-Whitney U test, linear, and binary logistic regression.

RESULTS

Diabetes was identified in 25/135 patients (18.5%). Diabetic patients had worse DASH and VAS score at presentation (P < 0.0001) and presented with a higher grade of AC (P < 0.0001) and lower range of motion (P < 0.01) compared to non-diabetics. Higher DASH (P = 0.025) and VAS scores (P = 0.039) at presentation were linked to worse functionality at 6 months. Presence and duration of diabetes, and the number of hydrodistension repeats, correlated with worse VAS and DASH scores at 6 months. The number of procedure repeats was the only independent predictor of complete pain resolution at 6 months (OR 0.418, P = 003).

CONCLUSION

Diabetes is linked to more severe AC at presentation and worse outcomes in patients undergoing US-guided hydrodistension. In resistant cases, repeating the intervention is independently linked to worse outcomes for at least 6 months post-intervention.

Ultrasound-Guided Hydrodistension for Adhesive Capsulitis: Is There Any Adjunct Effect of Immediate Post-Procedural Manipulation Over Instructed Physical Therapy?

OBJECTIVES

To compare the additive value of immediate post-procedural manipulation versus physiotherapy, following ultrasound (US)-guided hydrodistention of the glenohumeral joint (GHJ) in patients with adhesive capsulitis (AC) and define predictors of outcome.

METHODS

Within a 19-month period, 161 consecutive patients with AC were prospectively enrolled and allocated to two groups according to treatment, based on patients' individual preferences: 1) group-I, US-guided hydrodistension plus immediate post-procedural manipulations and 2) group-II, US-guided hydrodistension plus supervised physiotherapy program. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and a visual analog scale (VAS) were used for clinical assessment at baseline (immediately after treatment), 1, 3, and 6 months. Comparisons were performed with Mann-Whitney U test and Kolmogorov-Smirnov test. Linear regression was used to identify predictors of outcome. P value <.05 defined significance.

RESULTS

GHJ hydrodistension with manipulation or physiotherapy was linked to clinical improvement at all follow-up time-points. DASH scores of group-I remained constantly lower than DASH scores of group-II at all time-points (P < .001). VAS scores were lower in group-I than group-II at 1 and 3 months (P < .001 and P = .0019, respectively). Both groups had improved to a similar degree with respect to pain at 6 months (P = .29). The performance of post-interventional manipulations was predictive of improved shoulder functionality (as assessed with DASH scores) at all time-points, while low-grade disease and milder symptoms at presentation were associated with improved short-term pain.

CONCLUSIONS

Immediate post-procedural manipulations appeared to be superior to physiotherapy following GHJ hydrodistension for AC in terms of shoulder functionality during a 6-month follow-up period. Post-interventional manipulations, the stage of AC and lower DASH and VAS scores at presentations were predictive of improved outcome.

Anchoring Apparatus of Long Head of the Biceps Tendon: Ultrasonographic Anatomy and Pathologic Conditions

The long head of the biceps tendon (LHBT) has been recognized as an important generator of anterior shoulder pain, causing a significant reduction in the shoulder flexion range. Various tendinous and ligamentous structures form the anchoring apparatus of the LHBT along its course to maintain its appropriate location during shoulder movements, including the coracohumeral ligament (CHL), superior glenohumeral ligament (SGHL), subscapularis (SSC) tendon and supraspinatus (SSP) tendon as well as the less recognized tendons of pectoralis major (PM), latissimus dorsi (LD) and teres major (TM). Lesions of this stabilizing apparatus may lead to an instability of the LHBT, resulting in pain at the anterior shoulder. Ultrasonography (US) has been increasingly used in the assessment of shoulder injuries, including the anchoring apparatus of the LHBT. An accurate diagnosis of these injuries is often challenging, given the complex anatomy and wide spectrum of pathologies. In this review article, US anatomy and common pathologic conditions that affect the anchoring apparatus of the LHBT are discussed, including biceps pulley lesions, adhesive capsulitis, chronic pathology of SSC and SSP tendons, tears in the PM tendon and injuries to the LD and TM. Knowledge of a normal anatomy, an appropriate scanning technique and US findings of common pathologic conditions are the keys to accurate diagnoses.

MR arthrography: correlation between anatomic intraarticular variants of the long head of the biceps tendon (long head biceps tendon) and superior labral anterior to posterior (SLAP) lesions

Background

The purpose of this work is to characterize the anatomy of the intraarticular portion of the long head of the biceps tendon (long head biceps tendon) using magnetic resonance (MR) arthrography by investigating whether anatomical variants may facilitate the onset of a supraequatorial lesion (superior labral anterior to posterior, SLAP).

Materials and methods

In 482 shoulder MR arthrographies, we considered the anatomical variants of the intraarticular portion of the long head of the biceps tendon classified according to Dierickx’s arthroscopic classification; lesions of supraequatorial structures were considered in the data analysis. For each anatomical variant, correlation with SLAP and the odd ratio were statistically evaluated, using Fisher’s exact (or chi-squared) test and logistic regression analysis, respectively.

Results

In the mesotenon-type variant, the SLAP frequency was higher than expected [χ² (df = 4) = 14.9, p = 0.005] with a higher risk of developing a type I SLAP (p = 0.0003). In the adherent-type variant, the type II SLAP frequency was higher than expected [χ² (df = 3) = 18.1, p = 0.0004] with a higher risk of developing type II SLAP (p = 0.0001). Two cases of “split” (SPL) long head biceps tendon had III and type IV SLAP, respectively. These patients have a higher risk for type IV SLAP [odds ratio (OR) 19.562, 95% confidence interval (CI) 1.604–238.541, p = 0.001]. An increased risk of developing SLAP type II was calculated for male subjects (OR 3.479, 95% CI 1.013–11.951, p = 0.019).

Conclusions

It is possible that adherence of the long head biceps tendon to the supraspinatus more often predisposes to a lesion of the superior glenoid labrum (SLAP), in view of the close relationships between the fibrocartilage and the bicipital anchor, probably related to the limited excursion of the intraarticular long head biceps tendon.

Anatomical variants of the intraarticular portion of the long head of the biceps tendon should be studied with MR arthrography.

Some anatomical variants are more frequently associated with supraequatorial lesions.

The higher frequency of lesions in the presence of certain anatomical variants is probably related to the limited excursion of the intraarticular long head biceps tendon.

The middle glenohumeral ligament: a classification based on arthroscopic evaluation

BACKGROUND

Although middle glenohumeral ligament (MGHL) variations have been shown in the literature, their clinical effect and relationship with intra-articular pathologies have yet to be revealed, except for the Buford complex. This study was designed to classify MGHL and to reveal its relationship with clinical pathologies.

METHODS

A total of 843 consecutive shoulder arthroscopies were evaluated retrospectively, and a classification system was proposed for MGHL with regard to its structure and its relation to the anterior labrum. The associations of each MGHL type with superior labrum anterior-posterior (SLAP) lesions, subscapularis tears, and anterior instability were investigated.

RESULTS

MGHL variations were grouped into 6 types according to the classification. A significant difference in favor of type 6 MGHL (Buford complex) was observed in the distribution of SLAP lesions (P < .001). There was no significant difference between MGHL types and the distribution of anterior instability history (P = .131) and subscapularis tears (P = .324).

CONCLUSION

SLAP lesions accompany type 6 MGHLs (Buford complex) significantly more frequently than other types. There is also a negative relation between the anterior instability and thicker MGHL variants.

MRI morphological evaluation of humeral head bone profile inside region of the biceps pulley reflection

OBJECTIVE

Evaluating humeral head bone profile inside biceps reflection pulley area in order to identify possible anatomical variants and any causes predisposing to tendon's instability of the long head of the biceps.

MATERIALS AND METHODS

This retrospective study analyzed 326 patients, 183 males and 143 females (age 15-88 years; average 51.5 years), who underwent MRI examination between 2013 and 2019. Biceps pulley reflection area morphology of 192 right shoulders and 134 left shoulders was assessed analyzing 309 MRI and 17 MR arthrography (MRA) shoulder exams. We investigated age and gender and the frequency of morphological variants among the patient groups.

RESULTS

Four possible morphological variants were identified: 95 with convex shape; 127 with flat shape; 77 with spiculated shape; and 12 with mixed morphology. Fifteen humeral bone profiles were not classifiable.

CONCLUSIONS

MRI was effective in defining humeral head anatomic variants inside the biceps pulley reflection area. The most frequent variants were flat or convex types.

The Comma Sign: An Anatomic Study

The "comma sign" is a comma-shaped arc of tissue located at the superolateral edge of the subscapularis at its insertion on the humeral head. It consists of the coracohumeral ligament (CHL) and the superior glenohumeral ligament (SGHL). It was recently recognized as an important landmark to aid surgeons in identifying the edge of a torn subscapularis tendon. The exact proportion of CHL and SGHL has not been precisely defined. The goal of this study was to dissect and more accurately define the composition of the comma tissue and its exact relationship to the subscapularis tendon. A total of 8 fresh frozen cadaveric shoulder specimens (mean age, 74 years; 5 male, 3 female) were dissected via a wide deltopectoral approach. Anatomic landmarks were identified, and measurements were taken with a digital caliper. The midpoint width of the SGHL and CHL and the composite insertion width of the subscapularis were measured. Measurements were taken 3 times each and averaged to calculate mean width. Mean midpoint width of the SGHL, CHL, and composite insertion was 5.99 mm (range, 5.25-6.91 mm), 5.13 mm (range, 4.28-5.72 mm), and 9.93 mm (range, 6.69-12.05 mm), respectively. The comma sign consists of approximately half SGHL (54%) and half CHL (46%) at its insertion to the subscapularis tendon, with an approximate width of 1 cm. With the increase in arthroscopic subscapularis repairs, knowledge of these dimensions will aid surgeons in discerning the comma tissue from other capsular elements and ultimately help in surgical restoration of native anatomy. [Orthopedics. 2021;44(4):e546-e548.].

Effectiveness of new nerve blocks method on the articular branches of the suprascapular and subscapular nerves to treat shoulder pain

To evaluate the effectiveness and safety of performing nerve blocks on the articular branches of the suprascapular and subscapular nerves for the treatment of shoulder pain caused by various pathologies.Fifty-two patients with shoulder pain were included in this study. Suprascapular and subscapular nerve blocks were performed with 2.5 mL anesthetic solution (2 mL of 0.5% bupivacaine and 0.5 mL of 2 mg/mL dexamethasone). The subjects were evaluated before the procedure and 1, 3, and 6 months afterward by means of the numeric rating scale and the shoulder pain and disability index. A post-injection pain reduction of >50% and <50% was considered a positive and negative response to the blocks, respectively.After nerve blocks, the mean numeric rating scale and shoulder pain and disability index scores were significantly reduced from pre-injection values, and this effect persisted for 6 months after injection. The positive and negative response groups consisted of 31 (60%) and 21 (40%) patients, respectively. The positive response group showed significantly better outcomes on the numeric rating scale and shoulder pain and disability index compared with the negative response group. No patients reported adverse effects either during or after the procedure.Performing nerve blocks on the articular branches of the suprascapular and subscapular nerves resulted in positive outcomes for shoulder pain patients. Regardless of shoulder pathology, this new injection method can be safely used in shoulder pain patients.

Does arthroscopic preemptive extensive rotator interval release reduce postoperative stiffness after arthroscopic rotator cuff repair?: a prospective randomized clinical trial

BACKGROUND

To investigate whether preemptive extensive rotator interval (RI) release during arthroscopic rotator cuff repair (ARCR) would reduce postoperative stiffness.

METHODS

From July 2015 to September 2016, a total of 80 patients who were scheduled for ARCR were enrolled and randomly allocated into 2 groups: the preemptive extensive RI release group (group 1, n=40) and the RI nonrelease group (group 2, n=40). The American Shoulder and Elbow Surgeons scale, Constant score, Korean Shoulder Scale (KSS), visual analog scale (VAS) pain score, and range of motion (ROM) were evaluated before surgery; 3, 6, and 12 months after surgery; and at last follow-up. Magnetic resonance imaging was performed at postoperative 12 months.

RESULTS

The mean follow-up period was 26.5 months. The functional and pain scores in both groups were significantly improved at the last follow-up (P < .05). Group 1 showed a significantly higher sum of ROM with a difference of 27° and 1.6 vertebral level of internal rotation compared to group 2 at postoperative 3 months (P < .05). Constant score and KSS were significantly higher in group 1 than in group 2 at this time point (P < .05). Functional scores and ROM were not significantly different between 2 groups at postoperative 6 or 12 months or at the last follow-up (P > .05). The retear rate and pathologic change of the long head of the biceps tendon during follow-up were not significantly different between the 2 groups (P > .05).

CONCLUSION

Arthroscopic preemptive extensive RI release can reduce early postoperative shoulder stiffness after ARCR but does not significantly change the overall clinical outcome after surgery.

Adhesive capsulitis: review of imaging findings, pathophysiology, clinical presentation, and treatment options

Adhesive capsulitis, commonly referred to as "frozen shoulder," is a debilitating condition characterized by progressive pain and limited range of motion about the glenohumeral joint. It is a condition that typically affects middle-aged women, with some evidence for an association with endocrinological, rheumatological, and autoimmune disease states. Management tends to be conservative, as most cases resolve spontaneously, although a subset of patients progress to permanent disability. Conventional arthrographic findings include decreased capsular distension and volume of the axillary recess when compared with the normal glenohumeral joint, in spite of the fact that fluoroscopic visualization alone is rarely carried out today in favor of magnetic resonance imaging (MRI). MRI and MR arthrography (MRA) have, in recent years, allowed for the visualization of several characteristic signs seen with this condition, including thickening of the coracohumeral ligament, axillary pouch and rotator interval joint capsule, in addition to the obliteration of the subcoracoid fat triangle. Additional findings include T2 signal hyperintensity and post-contrast enhancement of the joint capsule. Similar changes are observable on ultrasound. However, the use of ultrasound is most clearly established for image-guided injection therapy. More aggressive therapies, including arthroscopic release and open capsulotomy, may be indicated for refractory disease, with arthroscopic procedures favored because of their less invasive nature and relatively high success rate.

Glenoid and rotator interval dimension in patients older than 40 years after traumatic anterior shoulder dislocation

INTRODUCTION

The number of patients above 40 years suffering an anterior shoulder dislocation for the first time has recently increased. This study investigated the role of glenoid version, inclination and rotator interval dimension in patients older than 40 years with an anterior shoulder dislocation. We hypothesize that the rotator interval plays a more important role than the osseus alignment in older patients.

MATERIALS AND METHODS

Patients aged older than 40 years with a traumatic shoulder dislocation were compared with patients who had undergone magnetic resonance imaging (MRI) for a different reason. The MRIs of 61 dislocation group patients were compared with MRIs of 73 comparison group patients. Two shoulder surgeons measured glenoid version, inclination, height and width, rotator interval (RI) height, base (width) and area. The study and comparison group consisted of 61 patients with a mean age of 59 ± 9 years and 73 patients with a mean age of 57 ± 12, respectively.

RESULTS

The mean glenoid version of the dislocation group was - 4.9° ± 4.4° (retroversion) and mean inclination was 9.8° ± 8° (reclination). Mean rotator interval base, height and the rotator interval area was 46 ± 6 mm, 14 ± 5 mm and 33 ± 14 mm², respectively. The comparison group had a mean glenoid version of - 5.4° ± 5.4° and a mean inclination of 10.8° ± 6.2°. The rotator interval base was 41 ± 6 mm, the height was 16 ± 4 mm and the area was 34 ± 11 mm². The between-group differences were statistically significant for rotator interval height and base (p < 0.0001). A significant difference was revealed for the height-width ratio of the glenoid (p = 0.0001).

CONCLUSIONS

In patients older than 40 years who have suffered anterior shoulder dislocation, the shape of the glenoid rather than its spatial position is of significance. A wide and high rotator interval promotes anterior shoulder dislocation in these patients.

Rehabilitation of symptomatic atraumatic degenerative rotator cuff tears: A clinical commentary on assessment and management

STUDY DESIGN

Clinical Commentary.

INTRODUCTION

Atraumatic rotator cuff (RC) disease, is one of the most common cause of shoulder pain, which encompasses a continuum from tendinopathy to full thickness cuff tears. Extrinsic, intrinsic and environmental factors have been implicated in the pathophysiology of this disorder, affecting the clinical presentation of symptoms including pain and irritability. Successful rehabilitation of symptomatic atraumatic degenerative rotator cuff (SADRC) tears must address the underlying mechanisms causing dysfunction and correct modifiable factors.

PURPOSE OF THE STUDY

The purpose of this paper is to review the shoulder complex anatomy, introduce atraumatic degenerative RC pathology, differentiate between symptomatic and asymptomatic degenerative RC tears, propose an assessment and introduce the Rotator Cuff Protocol 1 (RCP1) designed by the clinical reasoning of one of the lead authors (LW) as a rehabilitation management approach for those clients who present with SADRC tears.

METHODS/RESULTS/DISCUSSION

N/A for clinical commentary.

CONCLUSIONS

The ability to identify SADRC tears should consider shoulder anatomy, extrinsic, intrinsic and environmental factors, and the consideration for the natural history of atraumatic partial and full thickness tears in the general population. A thorough clinical history and examination, which includes shoulder symptom modification tests, allows the examiner to determine at what phase the patient may start their exercise program. The RCP1 is a program that has been used clinically by many therapists and clients over the years and research is underway to test this protocol in atraumatic rotator cuff disease including SADRC tears.

LEVEL OF EVIDENCE

5.

Controversies In The Surgical Management Of Shoulder Instability: Associated Soft Tissue Procedures

Background:

The glenohumeral joint is a ball-and-socket joint that is inherently unstable and thus, susceptible to dislocation. The traditional and most common anatomic finding is the Bankart lesion (anterior-inferior capsule labral complex avulsion), but there is a wide variety of anatomic alterations that can cause shoulder instability or may be present as a concomitant injury or in combination, including bone loss (glenoid or humeral head), complex capsule-labral tears, rotator cuff tears, Kim´s lesions (injuries to the posterior-inferior labrum) and rotator interval pathology.

Methods:

A review of articles related to shoulder anatomy and soft tissue procedures that are performed during shoulder instability arthroscopic management was conducted by querying the Pubmed database and conclusions and controversies regarding this injury were exposed.

Results:

Due to the complex anatomy of the shoulder and the large range of movement of this joint, a wide variety of anatomic injuries and conditions can lead to shoulder instability, specially present in young population. Recognizing and treating all of them including Bankart repair, capsule-labral plicatures, SLAP repair, circumferential approach to pan-labral lesions, rotator interval closure, rotator cuff injuries and HAGL lesion repair is crucial to achieve the goal of a stable, full range of movement and not painful joint.

Conclusion:

Physicians must be familiarized with all the lesions involved in shoulder instability, and should be able to recognize and subsequently treat them to achieve the goal of a stable non-painful shoulder. Unrecognized or not treated lesions may result in recurrence of instability episodes and pain while overuse of some of the techniques previously described can lead to stiffness, thus the importance of an accurate diagnosis and treatment when facing a shoulder instability.

Single anterior portal: A better option for arthroscopic treatment of traumatic anterior shoulder instability?

Objective

The aim of this study was to compare single and double anterior portal techniques in the arthroscopic treatment of traumatic anterior shoulder instability.

Methods

A total of 91 cases who underwent arthroscopic Bankart repair for anterior shoulder instability were reviewed. The patients were divided into 2 groups as Group 1 (47 male and 2 female; mean age: 25.8 ± 6.8) for arthroscopic single anterior portal approach and Group 2 (41 male and 1 female; mean age: 25.4 ± 6.6) for the classical anterior double portal approach. The groups were compared for clinical scores, range of motion, analgesia requirement, complications, duration of surgery, cost and learning curve according to a short questionnaire completed by the relevant healthcare professionals.

Results

No statistically significant difference was found between the 2 groups in terms of pre-operative and post-operative Constant and Rowe Shoulder Scores, range of motion and complications (p > 0.05). In Group 2 patients, the requirement for post-operative analgesics was significantly higher (p < 0.001), whereas the duration of surgery was statistically significantly shorter in Group 1 (p < 0.001). In the assessment of the questionnaire, it was seen that a single portal anterior approach was preferred at a higher ratio (p = 0.035). The cost analysis revealed that the cost was 5.7% less for patients with a single portal.

Conclusion

In the arthroscopic treatment of traumatic anterior shoulder instability accompanied by a Bankart lesion, the anterior single portal technique is as successful in terms of clinical results as the conventional double portal approach. The single portal technique has advantages such as less postoperative pain, a shorter surgical learning curve and lower costs.

Level of Evidence

Level III, Therapeutic study.

Blood supply of the subacromial bursa and rotator cuff tendons on the bursal side

PURPOSE

Vascularity of the subacromial bursa and rotator cuff tendons is key factors in the pathogenesis of subacromial bursitis and impingement syndrome, rotator cuff tendinitis, and rotator cuff tears. The purpose of this study was to investigate and describe blood supply to the cranial and caudal parts of the subacromial bursa and the vascularity of the rotator cuff tendons on the bursal side.

METHODS

Fourteen fresh cadaveric shoulders from six females and eight males with a mean age of 71.7 (±10.8) years were studied. Before dissection, an arterial injection of 10% aqueous dispersion of latex was administered. Post-injection, the shoulders were fixed in an alcohol-formalin-glycerol solution.

RESULTS

The cranial and caudal bursa of all specimens was mainly supplied by the thoracoacromial, suprascapular, and anterior and posterior circumflex humeral arteries. The cranial part of the bursa was supplied anteriorly by the thoracoacromial artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third. The caudal part received arterial blood anteriorly from the anterior circumflex humeral artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third of the caudal bursa. In addition, the suprascapular artery branched at the upper surface of the coracohumeral ligament, and the subcoracoid artery branched at the under surface of the same ligament.

CONCLUSION

The subacromial bursa appears well vascularized. The results of the present investigation showed that blood supply to the subacromial bursa at the caudal part and rotator cuff tendons on the bursal side was linked to the same arteries. The subcoracoid artery supplied interval rotator structures close to the caudal bursa. It is the wish of the authors that this meticulous anatomical work will help surgeons in their day-to-day clinical work, e.g. to minimize the risk of complications such as perioperative bleeding.

Rotator interval closure has no additional effect on shoulder stability compared to Bankart repair alone

PURPOSE

Arthroscopic Bankart repair (ABR) provides satisfactory results for recurrent anterior shoulder instability, but the high recurrence rate post-ABR remain a concern. One of the adjunct procedures proposed to improve ABR results is arthroscopic rotator interval closure (ARIC). This study prospectively evaluated the outcomes of ABRs alone compared to combined ABR + ARIC and identified risk factors related to failure of each procedure.

METHODS

Thirty-nine consecutive patients (mean age 23.1 (18.3-37.5) years; 37 males) underwent arthroscopic stabilization for recurrent anterior traumatic shoulder instability. Twenty patients underwent ABR alone and 19 underwent ABR + ARIC. Remplissage was added when glenoid engagement was observed during surgery. All patients were prospectively followed, and their postoperative courses were reviewed and functionally assessed at the last visit.

RESULTS

The re-dislocation rate was higher in the ABR + ARIC group compared to the ABR only group at a mean follow-up of 4.2 (2-5.6) years (3 vs. 0, P = 0.06). More subluxations were found in the ABR only group (2 vs. 1, respectively; P = 0.58). The final limitation of range of motion (ROM) compared with the preoperative ROM was similar in both groups. Remplissage procedures were performed more often in the ABR only group [12 (60%) vs. 4 (21%), P = 0.013].

CONCLUSIONS

ARIC performed as an adjunct to ABR showed no superiority in attaining value-added stability compared to ABR alone. Adding a remplissage procedure may achieve better stability.

LEVEL OF EVIDENCE

Level 2.

Adhesive capsulitis of the shoulder: review of pathophysiology and current clinical treatments

Adhesive shoulder capsulitis, or arthrofibrosis, describes a pathological process in which the body forms excessive scar tissue or adhesions across the glenohumeral joint, leading to pain, stiffness and dysfunction. It is a debilitating condition that can occur spontaneously (primary or idiopathic adhesive capsulitis) or following shoulder surgery or trauma (secondary adhesive capsulitis). Here, we review the pathophysiology of adhesive shoulder capsulitis, highlighting its clinical presentation, natural history, risk factors, pathoanatomy and pathogenesis. Both current non-operative and operative treatments for adhesive capsulitis are described, and evidence-based studies are presented in support for or against each corresponding treatment. Finally, the review also provides an update on the gene expression profile of adhesive capsulitis and how this new understanding can help facilitate development of novel pharmacological therapies.

The Rotator Interval of the Shoulder: Implications in the Treatment of Shoulder Instability

Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes.

Isolated arthroscopic rotator interval closure for shoulder instability

We present our technique for isolated arthroscopic rotator interval closure in the treatment of mild symptomatic glenohumeral instability in the absence of a labral tear. A careful history, physical examination, and imaging help to identify a select subset of atraumatic instability patients who may benefit from this procedure, and diagnostic arthroscopy can provide further evidence. By use of a posterior viewing portal with anterior and anterolateral working portals, the anterior capsuloligamentous complex is mobilized, and the rotator interval is closed with carefully placed sutures to advance the capsule superiorly and provide tension through decreased capsular volume.

Arthroscopic anatomy of the subdeltoid space

From the first shoulder arthroscopy performed on a cadaver in 1931, shoulder arthroscopy has grown tremendously in its ability to diagnose and treat pathologic conditions about the shoulder. Despite improvements in arthroscopic techniques and instrumentation, it is only recently that arthroscopists have begun to explore precise anatomical structures within the subdeltoid space. By way of a thorough bursectomy of the subdeltoid region, meticulous hemostasis, and the reciprocal use of posterior and lateral viewing portals, one can identify a myriad of pertinent ligamentous, musculotendinous, osseous, and neurovascular structures. For the purposes of this review, the subdeltoid space has been compartmentalized into lateral, medial, anterior, and posterior regions. Being able to identify pertinent structures in the subdeltoid space will provide shoulder arthroscopists with the requisite foundation in core anatomy that will be required for challenging procedures such as arthroscopic subscapularis mobilization and repair, biceps tenodesis, subcoracoid decompression, suprascapular nerve decompression, quadrangular space decompression and repair of massive rotator cuff tears.

Variability of the capsular anatomy in the rotator interval region of the shoulder

PURPOSE

Anterior shoulder anatomy is as complex and variable as its descriptive terminology. A detailed understanding of normal anatomic variability is critical to accurate performance, description, and evaluation of the procedures involving the rotator interval. We aimed to define, arthroscopically, the anatomic variability in the rotator interval region of the shoulder and to compare these results to the findings of previous cadaveric studies.

METHODS

The rotator interval anatomy of 104 consecutive patients was classified according to the system of DePalma. Anatomic variability was evaluated and compared with findings of previous authors.

RESULTS

Shoulders were classified as follows: 59% type 1 (rotator interval capsular opening [RICO] superolateral to the MGHL); 1% type 2 (RICO inferomedial to the middle glenohumeral ligament [MGHL]); 22% type 3 (2 RICOs: 1 above and 1 below the MGHL); 9% type 4 (large RICO, no MGHL); 0% type 5 (the MGHL is manifested as 2 small RICOs); 7% Type 6 (no RICO); and 3% distinct Buford complex. We found a larger percentage of type 1 shoulders and a lower percentage of type 3 shoulders relative to prior open cadaveric dissections. No difference in the distribution of DePalma types was noted based surgical indication.

CONCLUSIONS

The anatomy of the rotator interval as viewed arthroscopically is complex and variable. While DePalma types 1 and 3 are most commonly encountered, other anatomic variants are frequent and should be considered when assessing and manipulating structures in region of the rotator interval and anterior shoulder.

Distributions of types I, II and III collagen by region in the human supraspinatus tendon

The mechanical properties of the human supraspinatus tendon (SST) are highly heterogeneous and may reflect an important adaptive response to its complex, multiaxial loading environment. However, these functional properties are associated with a location-dependent structure and composition that have not been fully elucidated. Therefore, the objective of this study was to determine the concentrations of types I, II and III collagen in six distinct regions of the SST and compare changes in collagen concentration across regions with local changes in mechanical properties. We hypothesized that type I collagen content would be high throughout the tendon, type II collagen would be restricted to regions of compressive loading and type III collagen content would be high in regions associated with damage. We further hypothesized that regions of high type III collagen content would correspond to regions with low tensile modulus and a low degree of collagen alignment. Although type III collagen content was not significantly higher in regions that are frequently damaged, all other hypotheses were supported by our results. In particular, type II collagen content was highest near the insertion while type III collagen was inversely correlated with tendon modulus and collagen alignment. The measured increase in type II collagen under the coracoacromial arch provides evidence of adaptation to compressive loading in the SST. Moreover, the structure-function relationship between type III collagen content and tendon mechanics established in this study demonstrates a mechanism for altered mechanical properties in pathological tendons and provides a guideline for identifying therapeutic targets and pathology-specific biomarkers.

Imaging evaluation of the rotator cuff

The rotator cuff is a complex network of interwoven tendons that plays a key role in glenohumeral movement and stability. Cuff abnormality is a common source of shoulder pain, but the clinical presentation is often nonspecific and, as a result, diagnostic imaging, especially magnetic resonance imaging, plays a key role in evaluating these patients. This article reviews imaging modalities available for evaluating the cuff, normal cuff anatomy, and common pathologic conditions that affect it.

Lesions of the biceps pulley: diagnostic accuracy of MR arthrography of the shoulder and evaluation of previously described and new diagnostic signs

PURPOSE

To retrospectively determine the diagnostic accuracy of magnetic resonance (MR) arthrography of the shoulder in the evaluation of lesions of the biceps pulley and to evaluate previously described and new diagnostic signs.

MATERIALS AND METHODS

Institutional review board approval was obtained; the requirement for informed consent was waived. MR arthrograms of 80 consecutive patients (mean age, 34.2 years; 53 male, 27 female) with arthroscopically proved intact or torn pulley systems were assessed for the presence of a pulley lesion by three radiologists who were blinded to arthroscopic results. Criteria evaluated were displacement of the long head of the biceps tendon (LHBT) relative to the subscapularis tendon on oblique sagittal images (displacement sign), medial subluxation of the LHBT on transverse images, nonvisibility or discontinuity of the superior glenohumeral ligament (SGHL), presence of biceps tendinopathy, and rotator cuff tears adjacent to the rotator interval.

RESULTS

There were 28 pulley lesions noted at arthroscopy. For observers 1, 2, and 3, respectively: MR arthrography showed a sensitivity of 89%, 86%, and 82% and a specificity of 96%, 98%, and 87% in the detection of pulley lesions. Nonvisibility or discontinuity of the SGHL was sensitive (79%, 89%, and 79%) and specific (83%, 79%, and 75%). With the displacement sign, sensitivity was 86%, 82%, and 75% and specificity was 96%, 98%, 90%. Tendinopathy of the LHBT on oblique sagittal images showed a sensitivity of 93%, 82%, 64%; specificity was 81%, 96%, and 85%. Subluxation of the LHBT was insensitive (36%, 50%, and 64%) but specific (100%, 98%, and 96%).

CONCLUSION

MR arthrography is accurate in the detection of pulley lesions; the displacement sign, nonvisibility or discontinuity of the SGHL, and tendinopathy of the LHBT on oblique sagittal images are the most accurate criteria for the detection of pulley lesions.

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%.

Biomechanical and histological analysis after tenotomy of the long head of the biceps in the rabbit shoulder model

Tenotomy of the long head of the biceps tendon (LHBT) is gaining popularity in shoulder surgery. We evaluated biomechanical and histological changes after tenotomy in a rabbit LHBT tenotomy model to confirm that autotenodesis is a phenomenon that occurs after the procedure. Twenty-three rabbits were included. The right shoulder was harvested from 10 randomly selected rabbits. The shoulders were tested to determine the pullout strength of LHBT at the bicipital groove immediately after being tenotomized. The left shoulder of three of these rabbits also underwent histological analysis. The other 13 rabbits underwent LHBT tenotomy (tenotomy model). Six weeks post-operatively, 10 were assigned for biomechanical study, and three underwent histological analysis. The pullout strength and histology were compared with the immediate post-tenotomy data. The pullout strength of the immediate post-tenotomy (5.53 ± 2.22 N) was significantly (p < 0.001) less than the pullout strength of the 6 weeks post-tenotomy model (44.07 ± 7.75 N). On histological analysis, marked fibrosis was noted around the LHBT at the bicipital groove in the 6 weeks post-tenotomy model. Adhesion of the LHBT at the bicipital groove after tenotomy, which is called "autotenodesis," is a definite phenomenon that could help the tendon resist distal migration of the LHBT after tenotomy. These results support execution of biceps tenotomy in shoulder surgery.

The rotator interval and long head biceps tendon: anatomy, function, pathology, and magnetic resonance imaging

The rotator interval is an anatomically defined triangular area located between the coracoid process, the superior aspect of the subscapularis, and the anterior aspect of the supraspinatus. It is widely accepted that the rotator interval structures fulfill a role in biomechanics and pathology of the glenohumeral joint and long head biceps tendon. However, there is ongoing debate regarding the biomechanical details and the indications for treatment. A better understanding of rotator interval anatomy and function will lead to improved treatment of rotator interval abnormalities, and guide the indications for imaging and surgical intervention.

A physician's guide to the physical examination of the shoulder

Shoulder pain is the third most frequent musculoskeletal complaint presented to physicians. Often considered a benign entity by patients and even their physicians, shoulder disorders can have a devastating effect on a patient's ability to function, as well as serve as an indicator of poor general health. For these reasons, it is important for the physician to be able to identify the etiology of a patient's shoulder problem(s). However, making a correct diagnosis is often difficult because there can be many causes for a patient's shoulder pain, weakness, or loss of function. Moreover, the shoulder girdle is an intricate group of structures that work together to allow for the largest range of motion in the body. This complexity makes it difficult to diagnose a patient's condition(s) based on history alone. A thorough and well-performed physical examination is the key to making a correct diagnosis and helping to distinguish different etiologies of shoulder dysfunction. In this article, we review relevant shoulder anatomy and biomechanics, and general shoulder examinations with special tests for various shoulder pathologies. We provide an effective and methodical approach to the physical examination of the shoulder.

Regional variation in human supraspinatus tendon proteoglycans: decorin, biglycan, and aggrecan

While tendons typically undergo primary tensile loading, the human supraspinatus tendon (SST) experiences substantial amounts of tension, compression, and shear in vivo. As a result, the functional roles of the extracellular matrix components, in particular the proteoglycans (PGs), are likely complex and important. The goal of this study was to determine the PG content in specific regions of the SST that exhibit differing mechanical function. The concentration of aggrecan, biglycan, and decorin was determined in six regions of the human SST using immunochemical techniques. We hypothesized that aggrecan concentrations would be highest in areas where the tendon likely experiences compression; biglycan levels would be highest in regions likely subjected to injury and/or active remodeling such as the anterior regions; decorin concentrations would be highest in regions of greatest tensile stiffness. Our results generally supported these hypotheses and demonstrated that aggrecan and biglycan share regional variability, with increased concentration in the anterior and posterior regions and smaller concentration in the medial regions. Decorin, however, was in high concentration throughout all regions. The data presented in this study represent the first regional measurements of PG in the SST. Together with our previous regional measurements of mechanical properties, these data can be used to evaluate SST structure-function relationships. With knowledge of the differences in specific PG content, their spatial variations in the SST, and their relationships to tendon mechanics, we can begin to associate defects in PG content with specific pathology, which may provide guidance for new therapeutic interventions.

Arthroscopic anatomy, variants, and pathologic findings in shoulder instability

Shoulder instability is a common diagnosis that often requires surgical treatment. A detailed knowledge of the shoulder anatomy and its stabilizing structures is of utmost importance for successful treatment of shoulder instabilities. Identifying anatomic variants (e.g., sublabral hole, meniscoid labrum, cordlike middle glenohumeral ligament, and Buford complex) and distinguishing them from pathologic findings may be especially difficult, as shown by the high interobserver variability. Over the last decade, basic research and arthroscopic surgery have improved our understanding of the shoulder anatomy and pathology. In the context of shoulder instability, injuries of the glenoid (bony Bankart), injuries of the glenoid labrum superiorly (SLAP) or anteroinferiorly (e.g., Bankart, anterior labroligamentous periosteal sleeve avulsion, and Perthes), capsular lesions (humeral avulsion of the glenohumeral ligament), accompanying cartilage lesions (Hill-Sachs, glenolabral articular disruption), and rotator interval and pulley lesions, as well as signs of dynamic instability impingement (posterior-superior impingement, anterior-superior impingement) can be exactly diagnosed (magnetic resonance imaging with intra-articular gadolinium, arthroscopy) and treated (arthroscopy). Therefore the purpose of this article is to review the current literature concerning shoulder anatomy/pathology related to shoulder stability/instability to improve clinical diagnosis and surgical treatment of our patients.

Fiber components of the shoulder superior labrum

PURPOSE

The purpose of this study was to investigate the anatomy of the superior glenoid labrum focusing on the fiber arrangement of its components.

METHODS

Forty-nine embalmed shoulder girdles were removed and each posterior capsule was incised. After recording the macroscopic findings 12 superior-half glenoids were histologically examined. In nine serially sectioned glenoids, four were cut parallel to and five were cut vertical to the glenoid surface. The remaining three glenoids were radially sectioned at the clock position for each hour between 10:00 and 14:00.

RESULTS

The superior labrum had a semi-circular fiber component along the outer margin of the glenoid. In addition, a so-called 'sheet-like structure' which branched off the rotator interval and contained many elastic fibers, attached to its anterosuperior portion. The fibers of the sheet-like structure mixes with fibers of the semi-circular component and ran posteriorward. The fibers of the long head of the biceps tendon extended posteriorward from its origin along the glenoid edge. These fibers communicated with other labrum fibers and became a major element of the posterior portion.

CONCLUSION

The superior labrum is not homogenous. The posterior portion mainly consists of the robust fiber component of the long head of the biceps tendon. The anterosuperior portion includes fibers of the sheet-like structure which contains numerous elastic fibers. Tensile stress from the rotator interval might be conveyed to the anterosuperior labrum.

Stretching positions for the coracohumeral ligament: Strain measurement during passive motion using fresh/frozen cadaver shoulders

BACKGROUND

Contracture of the coracohumeral ligament is reported to restrict external rotation of the shoulder with arm at the side and restrict posterior-inferior shift of the humeral head. The contracture is supposed to restrict range of motion of the glenohumeral joint.

METHODS

To obtain stretching position of the coracohumeral ligament, strain on the ligament was measured at the superficial fibers of the ligament using 9 fresh/frozen cadaver shoulders. By sequential measurement using a strain gauge, the ligament strain was measured from reference length (L0). Shoulder positions were determined using a 3 Space Tracker System. Through a combination of previously reported coracohumeral stretching positions and those observed in preliminary measurement, ligament strain were measured by passive external rotation from 10° internal rotation, by adding each 10° external rotation, to maximal external rotation.

RESULTS

Stretching positions in which significantly larger strain were obtained compared to the L0 values were 0° elevation in scapula plane with 40°, 50° and maximum external rotation (5.68%, 7.2%, 7.87%), 30° extension with 50°, maximum external rotation (4.20%, 4.79%), and 30° extension + adduction with 30°, 40°, 50° and maximum external rotation (4.09%, 4.67%, 4.78%, 5.05%)(P < 0.05). No positive strain on the coracohumeral ligament was observed for the previously reported stretching positions; ie, 90° abduction with external rotation or flexion with external rotation.

CONCLUSIONS

Significant strain of the coracohumeral ligament will be achieved by passive external rotation at lower shoulder elevations, extension, and extension with adduction.

Arthroscopic rotator interval closure in shoulder instability repair: a retrospective study

BACKGROUND

Arthroscopic Bankart repair (ABR) is a standard treatment for recurrent anterior shoulder instability. Young age, hyperlaxity, loss of bone stock and multidirectional or voluntary type of instability are all associated with failure of this procedure. Rotator interval laxity is associated with shoulder instability, whereas rotator interval closure increases humeral head stability and reduces shoulder range of motion.

METHODS

The records of patients with recurrent anterior shoulder dislocations who underwent ABR with or without arthroscopic rotator interval closure (ARIC) in our department between 1999 and 2007 were reviewed. Rates of recurrent dislocation or symptomatic subluxation as well as functional outcome were evaluated using Walch-Dupley score.

RESULTS

Three (8.1%) of the 37 ABR+ARIC patients (age 19-44 years, 32 males) had re-dislocated their shoulder at 42±16 months following the procedure, all of which had systemic joint hyperlaxity. Six (13%) of the 46 ABR patients (age 19-39 years, 42 males) had re-dislocated their shoulder at 13±14 months, three of which had systemic joint hyperlaxity and dislocated their shoulder within 1 year following the operation. Systemic joint hyperlaxity (28% of ABR and 41% of ABR+ARIC patients) was significantly associated with recurrent dislocation and poor functional outcome. ABR+ARIC patients had slightly more limited range of motion with similar good and excellent functional results (75%) at final follow up time.

CONCLUSIONS

Systemic joint hyperlaxity is a risk factor for failure of ABR. When ARIC is performed in combination with ABR, it may have an additive effect on shoulder stability.

The rotator interval: a review of anatomy, function, and normal and abnormal MRI appearance

OBJECTIVE

The purpose of this article is to review imaging of the rotator interval, an anatomically complex region in the shoulder that plays an important role in the normal function of the shoulder joint. The rotator interval can be difficult to evaluate by imaging, and it is not routinely evaluated arthroscopically unless the clinical examination or imaging findings suggest an abnormality of the rotator interval. Rotator interval pathology is implicated in glenohumeral instability, biceps instability and adhesive capsulitis-entities which remain a challenge to diagnose and treat.

CONCLUSION

Imaging can play an important role in increasing suspicion for injury to the rotator interval so that this region can be evaluated and appropriate treatment can be initiated.

Anatomy of the superior glenohumeral ligament

BACKGROUND

The aim of the present study was to give a detailed, anatomical description of the superior glenohumeral ligament and its relationship with the neighbouring structures in the rotator interval.

METHOD

Twenty-seven cadaveric shoulder specimens were dissected in fine detail to describe superior glenohumeral ligament and additional histologic examination was performed.

RESULTS

The superior glenohumeral ligament is a constant, gross anatomic structure that was present in all of twenty-seven investigated specimens. The fibers of the superior glenohumeral ligament could be divided into two groups - the oblique and direct fibers. The direct fibers of the superior glenohumeral ligament arise from the glenoid labrum, run parallel with the tendon of the long head of the biceps brachii towards the lesser tubercle, which they also partly insert onto. The rest of the direct fibers course into the bottom of the bicipital groove and bridge over it, forming the superior part of the transverse humeral ligament. The oblique fibers arise from the supraglenoid tubercle, run over the intraarticular part of the tendon of the long head of the biceps brachii and insert below the coracohumeral ligament into the humeral semicircular ligament.

CONCLUSION

Due to its anatomic composition and tight connection with the neighboring articular structures, the superior glenohumeral ligament is involved in the stabilizing mechanisms of the intraarticular part of the tendon of the long head of the biceps brachii and plays an important role in the variety of clinical disorders that occur within the rotator interval.

Coracoid pain test: a new clinical sign of shoulder adhesive capsulitis

Patients with adhesive capsulitis were clinically evaluated to establish whether pain elicited by pressure on the coracoid area may be considered a pathognomonic sign of this condition. The study group included 85 patients with primary adhesive capsulitis, 465 with rotator cuff tear, 48 with calcifying tendonitis, 16 with glenohumeral arthritis, 66 with acromioclavicular arthropathy and 150 asymptomatic subjects. The test was considered positive when pain on the coracoid region was more severe than 3 points (VAS scale) with respect to the acromioclavicular joint and the anterolateral subacromial area. The test was positive in 96.4% of patients with adhesive capsulitis and in 11.1%, 14.5%, 6.2% and 10.6% of patients with the other four conditions, respectively. A positive result was obtained in 3/150 normal subjects (2%). With respect to the other four diseases, the test had a sensitivity of 0.96 and a specificity ranging from 0.87 to 0.89. With respect to controls, the sensitivity and specificity were 0.99 and 0.98, respectively. The coracoid pain test could be considered as a pathognomonic sign in physical examination of patients with stiff and painful shoulder.

A minimally invasive surgical technique to treat distal clavicle fractures

Treatment of distal clavicle fractures ranges from nonoperative to operative approaches. Various surgical procedures have been described in the literature, each with potential complications. For fractures treated operatively, the goal is to maximize stability and functionality while minimizing pain and deformity. This article describes a double-button suture system using a mini-open technique to repair a distal clavicle fracture providing stable fixation with minimal disruption of the surrounding anatomy.

An anatomic and histologic study of the coracohumeral ligament

Although the anatomy and histology of the coracohumeral ligament (CHL) play an important role in the diagnosis and treatment of frozen shoulder, they remain unclear. Our objective was to study the anatomic features of the CHL and analyze its histology. Twenty-six fresh-frozen, normal cadaveric shoulders were used to examine the position and morphology of the CHL and their relationship with the superior glenohumeral ligament and to determine the CHL's histologic features in comparison with the joint capsule and coracoacromial ligament. The CHLs were all located in the rotator interval, with an irregular trapezoidal structure. The subacromial bursa was above the CHL, and the subcoracoid bursa was below the it. The CHLs in all shoulders originated from the lateral aspect of the base of the coracoid process. In 11 shoulders, it inserted into the supraspinatus tendon, whereas in 11 other shoulders, it inserted into the rotator interval. In 3 shoulders, the CHLs were split and inserted into both the supraspinatus and subscapularis tendons, respectively. Finally, the CHL in 1 shoulder only inserted into the subscapularis tendon. We also observed that the pectoralis minor tendons in 4 shoulders passed over the coracoid process top and inserted into the CHLs. In 11 shoulders, a complex of the CHL and the superior glenohumeral ligament was formed. Histologically, the CHL was found to be similar to the joint capsule without any ligament features. The position, morphology, and origin of the CHL did not change much, but its insertion varied greatly. In addition, the CHL had the histologic feature of a capsule, not a ligament.

Rotator interval dimensions in different shoulder arthroscopy positions: a cadaveric study

The rotator interval was defined as a triangular structure, where the base of the triangle was the coracoid base, the upper border was the anterior margin of the supraspinatus, and the lower border was the superior margin of the subscapularis muscle-tendon unit. We evaluated the rotator interval dimensions in 15 shoulders from 10 lightly embalmed adult cadavers in 3 shoulder arthroscopy positions: 0 degrees of abduction and 30 degrees of flexion (beach chair [BC]), 45 degrees of abduction and 30 degrees of flexion (lateral decubitus 1), and 70 degrees of abduction and 30 degrees of flexion (lateral decubitus 2). In each shoulder position, measurements were made in neutral rotation (NR), 45 degrees of external rotation (ER), and 45 degrees of internal rotation (IR). The coracoid base lengthened with IR in all positions and shortened in ER in the lateral decubitus position but not in the BC position. Abduction significantly lengthened the coracoid base, which was shortest in the BC position with ER (24 +/- 4 mm) and longest in the lateral decubitus 2 position with IR (33 +/- 5 mm). The coracoid base, where sutures are placed during plication of the interval, was observed to lengthen and, therefore, loosen with IR and abduction. To prevent postoperative ER restriction, plication should be made in ER or neutral rotation when operating in the BC position and the degree of abduction should be decreased and the shoulder held in ER when operating in the lateral decubitus position.