Superior Labral Anteroposterior Lesions Research Articles

Posterior shoulder labrocapsular structures in all aspects; 3D volumetric MR arthrography study.

Pathologies of the posterior labrocapsular structures of the shoulder joint are far less common than anterior labrocapsuloligamentous lesions. Most of these pathologies have been associated with traumatic posterior dislocation. A smaller portion of the lesions include posterior extension of superior labral anteroposterior lesions, posterior superior internal impingement, and damage to the posterior band of the inferior glenohumeral ligament. Labrocapsular anatomic variations of the posterior shoulder joint can mimic labral pathology on conventional MR and occasionally on MR arthrographic images. Knowledge of this variant anatomy is key to interpreting MR images and studying MR arthrography of the posterior labrocapsular structure to avoid misdiagnosis and unnecessary surgical procedures. In this article, we review normal and variant anatomy of the posterior labrocapsular structure of the shoulder joint based on MR arthrography and discuss how to discriminate normal anatomic variants from labrocapsular damage.

Type V superior labral anterior-posterior (SLAP) lesion in recurrent anterior glenohumeral instability

The literature has reported debatable diagnostic accuracy of clinical provocative tests for a type II superior labral anteroposterior (SLAP) lesion, especially in the context of a type V SLAP (concurrent Bankart and type II SLAP) lesion. This study was conducted to determine whether the investigated provocative tests offer reliable predictive values in the diagnosis of type II SLAP lesions in patients with recurrent anterior glenohumeral (GH) instability. This prospective case-control study carried out between September 2014 and September 2018 included 51 patients with post-traumatic recurrent anterior GH instability. Patients were prospectively evaluated for type II SLAP lesions by 9 provocative tests: Jobe relocation test, abduction-external rotation test, anterior slide test, biceps load test I, biceps load test II, pain provocation test, labral tension test, crank test, and the O'Driscoll dynamic labral shear test. The results of these tests were compared with findings of diagnostic arthroscopic GH examinations (control). Statistical analysis revealed the mean age of the studied group to be 26.1 ± 7.56years, with male predominance (50 patients; 98.04%). Arthroscopic examination revealed a Bankart lesion in isolation and in association with a type II SLAP lesion (ie, a type V SLAP lesion) in 15 (29.4%) and 36 (70.6%) patients, respectively. The anterior slide test yielded the highest positive and lowest negative likelihood ratios (2.91 and 0.52, respectively). Except for the anterior slide test, which can be validated for the clinical diagnosis of type II SLAP lesions in patients with traumatic recurrent anterior GH instability, the investigated tests offer poor predictive values and should be cautiously used in clinical practice.

The chondral print sign: what does it really mean?

The chondral print (CP) sign is a chondral change on the humeral head underneath the long head of the biceps (LHB) tendon. Several suggested causative links have been described, but the pathologic mechanism remains unclear. We designed this prospective cohort association study of 102 consecutive shoulder arthroscopies to investigate proposed associations of CP with LHB, rotator cuff, labral pathology, and other chondral lesions. Data collection was by a specifically designed pro forma, and statistical analysis was performed. We identified 24 patients (23.5%) with the CP sign. Patients were a mean age of 58 years. Shoulders with positive CP sign had associated pathologies: 16 superior labral anteroposterior (SLAP) tears, 4 LHB instabilities, and 11 other LHB lesions. We also recorded other chondral lesions, 10 humeral head and 12 on the glenoid surface. The overall arthroscopic appearance of CP signs could be classified into 3 different types. Statistical analysis revealed that the CP sign is not statistically associated with LHB instability, any other LHB pathologies, rotator cuff tears, or instability. The CP sign was statistically positively associated with SLAP lesions (but only if type 1 were included). There was a weak association of CP sign with age and a positive association of SLAP lesions with other (non-CP) humeral chondral lesions. Our prospective association study cannot determine the cause of the CP sign. It does not seem to be a reliable sign of LHB instability or of other LHB pathology. There is an association with age and degenerative SLAP lesions.

Imaging the Glenoid Labrum and Labral Tears.

The shoulder joint is the most unstable articulation in the entire human body. While this certainly introduces vulnerability to injury, it also confers the advantage of broad range of motion. There are many elements that work in combination to offset the inherent instability of the glenohumeral joint, but the glenoid labrum is perhaps related most often. Broadly, clinical unidirectional instability can be subdivided into anterior and posterior instability, which usually raise concern for anteroinferior and posteroinferior labral lesions, respectively. In the special case of superior labral damage, potential dislocation is blocked by structures that include the acromion; hence, while damage elsewhere commonly manifests as clinical instability, damage to the superior labrum is often described by the term microinstability. In this particular case, one of the radiologist's main concerns should be classic superior labral anteroposterior lesions. The glenoid labrum is also subject to a wide range of normal variants that can mimic labral tears. Knowledge of these variants is central to interpreting an imaging study of the labrum because misdiagnosis of labral variants as tears can lead to superfluous surgical procedures and decreased shoulder mobility. This article reviews labral anatomy and normal labral variants, describes their imaging features, and discusses how to discriminate normal variants from labral tears. Specific labral pathologic lesions are described per labral quadrant (anteroinferior, posteroinferior, and superior), and imaging features are described in detail. Online supplemental material is available for this article. ©RSNA, 2016.

Glenohumeral instability

• Normal anatomical variants: ○ Sublabral foramen ○ Sublabral recess ○ Buford complex ○ Capsular insertions • Shoulder instability: ○ Anterior glenohumeral instability • Anteroinferior labral tear ○ Bankart lesion ○ Anterior labroligamentous periosteal sleeve avulsion lesion ○ Perthes lesion ○ Glenolabral articular disruption lesion • Extensive anterior labral tear • Anterosuperior labral tear • Glenohumeral ligament injury ○ SLAP lesion ○ Posterior glenohumeral instability ○ Posterior superior glenoid impingement MR arthrography is useful in diagnosing and characterizing the labral–ligamentous lesions resulting in glenohumeral instability. The sublabral foramen, sublabral recess and Buford complex are normal variants of the glenoid labrum, which must not be confused with true labral abnormalities. The most common type of glenohumeral instability is anteroinferior instability, characterized by avulsion of the anteroinferior labral–ligamentous complex, which is termed a Bankart lesion. Variants of the Bankart lesion, where the scapular periosteum remains intact, are the anterior labroligamentous periosteal sleeve avulsion lesion, the Perthes lesion and the glenolabral articular disruption lesion. Anterosuperior labral tears are uncommon and must be differentiated from a normal sublabral foramen. Anterior glenohumeral instability also occurs following injury to the glenohumeral ligaments, most commonly described as humeral avulsion of the inferior glenohumeral ligament lesion. The superior labral anteroposterior (SLAP) lesion is a superior labral tear that extends both anterior and posterior to the biceps tendon attachment. SLAP lesions have a complex classification but the presence and the extent of biceps tendon involvement is the most important feature. A SLAP II lesion must be distinguished from a normal sublabral recess. Patterns of injury seen in posterior instability are the reverse of those found following anterior dislocation with posterior labral tears referred to as a reverse Bankart lesion. Posterior superior glenoid impingement or internal impingement is when the posterosuperior aspect of the glenoid and the humeral head come into contact, causing injury to the interposed rotator cuff and posterosuperior labrum.

Superior Labral Anteroposterior Lesions of the Shoulder: Part 2, Mechanisms and Classification

The objectives of this article are to discuss the 10 distinct patterns of superior labral anteroposterior (SLAP) tears to facilitate adequate diagnosis and treatment. Correlations with clinical presentation, mechanism of injury, and treatment will enhance understanding. Imaging plays an important role in the diagnosis of SLAP tears. Knowledge of glenolabral anatomy, related structures and variants, proper imaging techniques, and a systematic approach to MRI interpretation is important in the diagnosis and treatment planning of the 10 types of SLAP lesions. Arthroscopy offers a means for definitive diagnosis.

Superior Labral Anteroposterior Lesions of the Shoulder: Part 1, Anatomy and Anatomic Variants

The objectives of this article are to provide a pictorial review of labral anatomy and physiology, with particular attention to commonly seen anatomic variants and pitfalls, and to present standard imaging techniques and approaches to MRI interpretation to facilitate diagnosis and treatment of superior labral anteroposterior (SLAP) lesions. Imaging plays an important role in the diagnosis of SLAP tears. Knowledge of glenolabral anatomy, related structures and variants, proper imaging techniques, and a systematic approach to MRI interpretation is important in the diagnosis and treatment planning of the 10 types of SLAP lesions. Arthroscopy offers a means for definitive diagnosis.

Superior Labral Anteroposterior Tears: Accuracy and Interobserver Reliability of Multidetector CT Arthrography for Diagnosis

To evaluate the accuracy and interobserver reliability of multidetector computed tomographic (CT) arthrography for the diagnosis and classification of superior labral anteroposterior (SLAP) lesions. Institutional review board approval and informed consent were obtained. Retrospective review of images from 161 multidetector CT arthrographic examinations was performed by two radiologists independently for detection and classification of SLAP lesions (type I-X), and sensitivity, specificity, accuracy, and interobserver agreement were evaluated. The SLAP group included 94 patients, and the no-SLAP group included 67 patients with normal labrum. At arthroscopy, a total of 88 SLAP lesions (excluding type I) were found. For detection of SLAP lesions excluding SLAP type I lesions, sensitivity, specificity, and accuracy were 94.3%, 76.7%, and 86.3% for reader 1 and 97%, 72.6%, and 86.3% for reader 2, respectively, and the interobserver agreement was very good (κ = 0.87). The distribution of SLAP lesions was as follows: six type I, 58 type II, one type III, one type IV, 16 type V, one type VI, five type VII, three type VIII, one type IX, one type V and VI, and one type V and VII. Percentages of correct classification of SLAP lesions were variable according to the types, but the overall percentage was noted to be 69.2% for reader 1 and 68.1% for reader 2. The interobserver agreement of classification of SLAP lesions was good (κ = 0.72). Multidetector CT arthrography shows high accuracy and good interobserver reliability for diagnosis of SLAP lesions in spite of its limitations in specific classification.

Identifying SLAP lesions: A meta-analysis of clinical tests and exercise in clinical reasoning

Objectives To identify all published accounts of diagnostic accuracy for clinical tests of Superior Labral Antero-Posterior (SLAP) lesion of the shoulder, and provide an estimate of the pooled likelihood ratio for those tests that have been evaluated at least three times. A clinical reasoning exercise is presented to illustrate clinical useability of the findings. Design Systematic review and meta-analysis. Methods An extensive review of international electronic databases was performed to identify all published works of diagnostic accuracy of any test proposed to be diagnostic for SLAP lesions of the shoulder. Statistical pooling of likelihood ratios was performed using a random-effects model to provide an estimate of the pooled positive likelihood ratio (PLR) for each test with at least three data points available. Results Twelve studies describing 14 tests were identified. Five tests had been evaluated at least 3 times in the published literature. Methodologic quality scoring was performed and data were extracted. The pooled PLR revealed that of the five tests studies, only Yergason's test demonstrates consistent evidence of significant diagnostic accuracy (PLR 2.29). Heterogeneity of effect sizes was present for the Crank test. The heterogeneity was substantially improved through removal of the effect from the study in which the test was initially described and validated. The fail-safe N statistic suggests that the findings for Yergason's test are robust to publication bias. None of the tests reviewed are very strong. Conclusions Among the clinical tests for SLAP lesions that have been published to date, Yergason's test is the only one that shows a significant ability to influence clinical decision making, based on the results of the current analysis. Methodologic inadequacies in the reporting of the publications are common, and caution must be exercised when drawing inferences from the results of these studies.

Magnetic Resonance Imaging of the Long Head of the Biceps Tendon

To evaluate coplanar imaging of the long head of the biceps tendon. We retrospectively compared coronal oblique magnetic resonance images aligned with the principal supraspinatus tendon and with the intra-articular biceps tendon in 21 patients. Magnetic resonance images were analyzed for lesions depicted, including superior labral anteroposterior (SLAP) tears. Arthroscopic findings were reviewed. Coronal oblique images aligned with intra-articular biceps tendon depicted 18 (86%) of 21 coplanar intra-articular biceps tendons. Coplanar images identified 6 cases of tendinosis, 1 tear, 3 intra-articular ruptures, and 20 (95.2%) of 21 exact origins of the tendon. Arthroscopy revealed 18 SLAP tears. The detection of SLAP lesions between both coronal oblique magnetic resonance images was significantly different (P = 0.007). Advantages included imaging of the intra-articular biceps tendon with least partial-volume effects, definition of SLAP lesions and the tendinous origin at the supraglenoid tubercle, depiction of intra-articular bicipital ruptures, and increased sensitivity and specificity for intra-articular lesions.

MR Arthrography in the Differential Diagnosis of Type II Superior Labral Anteroposterior Lesion and Sublabral Recess

MR Arthrography in the Differential Diagnosis of Type II Superior Labral Anteroposterior Lesion and Sublabral Recess

MR Arthrography in the Differential Diagnosis of Type II Superior Labral Anteroposterior Lesion and Sublabral Recess

The objective of our study was to assess the utility of five MR arthrographic findings in differentiating type II superior labral anteroposterior (SLAP) lesion from superior sublabral recess. The MR arthrograms of 55 patients (57 cases) with either type II SLAP lesion (34 cases) or superior sublabral recess (23 cases) who underwent arthroscopic surgery and MR arthrography were retrospectively reviewed. Two independent reviewers searched for the extension, direction, and shape of high signal intensity in the superior labrum on MR arthrograms. In addition, the presence of concomitant anterosuperior labral tear and anteroposterior extension of high signal intensity on axial images was evaluated. The frequencies of these findings in cases of type II SLAP lesion and sublabral recess were evaluated, and the statistical significance of each finding in differentiation of the two groups was assessed. Extension of high signal intensity behind the biceps anchor that extended beneath the labrum on fat-saturated oblique coronal T1-weighted images was found in 33 (97%) of the cases of type II SLAP lesion and 21 (91%) of the cases of sublabral recess. Laterally curved high signal intensity was found in 17 (50%) of the cases of type II SLAP lesion but in only four (17%) of the cases of sublabral recess. Globular or irregular shape of the superior labrum was present in 22 (65%) of the cases of type II SLAP lesion and in 10 (43%) of the cases of sublabral recess. Concomitant anterosuperior labral tear was seen in 14 (41%) of the cases of type II SLAP lesion but in only two (8.7%) of the cases of sublabral recess. Anteroposterior extension of high signal intensity in the superior labrum on fat-saturated axial T1-weighted images was detected in 33 cases of type II SLAP lesion (97%) and in 14 cases of sublabral recess (61%). Although the MR arthrographic findings were similar for type II SLAP lesion and sublabral recess, laterally curved high signal intensity on oblique coronal images, concomitant anterosuperior labral tear, and anteroposterior extension of high signal intensity on axial images were helpful findings in the diagnosis of type II SLAP lesion.

MR imaging in sports-related glenohumeral instability

Sports-related shoulder pain and injuries represent a common problem. In this context, glenohumeral instability is currently believed to play a central role either as a recognized or as an unrecognized condition. Shoulder instabilities can roughly be divided into traumatic, atraumatic, and microtraumatic glenohumeral instabilities. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement syndromes and chronic damage to intraarticular structures. Magnetic resonance (MR) arthrography is superior to conventional MR imaging in the diagnosis of labro-ligamentous injuries, intrinsic impingement, and SLAP (superior labral anteroposterior) lesions, and thus represents the most informative imaging modality in the overall assessment of glenohumeral instability. This article reviews the imaging criteria for the detection and classification of instability-related injuries in athletes with special emphasis on the influence of MR findings on therapeutic decisions.

Suprascapular intraneural ganglia and glenohumeral joint connections

Unlike the more commonly noted paralabral cysts (extraneural ganglia), which are well known to result in suprascapular nerve compression, only four cases of suprascapular intraneural ganglia have been reported. Because of their rarity, the pathogenesis of suprascapular intraneural ganglia has been poorly understood and a pathoanatomical explanation has not been provided. In view of the growing literature demonstrating strong associations between paralabral cysts and labral (capsular) pathology, joint connections, and joint communications, the authors retrospectively reviewed the magnetic resonance (MR) imaging studies and postoperative results in the two featured patients to test a hypothesis that suprascapular intraneural ganglia would have analogous findings. Two patients who presented with suprascapular neuropathy were found to have intraneural ganglia. Connections to the glenohumeral joint could be established in both patients through posterior labrocapsular complex tears. In neither patient was the joint connection identified preoperatively or intraoperatively, and cyst decompression was performed by itself without attention to the labral tear. The suprascapular intraneural ganglia extended from the glenohumeral joint as far proximally as the level of the nerves' origin from the upper trunk in the supraclavicular fossa. Although both patients experienced symptomatic improvement after surgery, neurological recovery was incomplete. In both cases, postoperative MR images revealed cyst persistence. In addition, previously unrecognized superior labral anteroposterior (SLAP) Type II lesions (tears of the superior labrum extending anteroposterior and involving the biceps anchor at the labrum without actual extension into the tendon) were visualized. In one patient with a persistent cyst, an MR arthrogram was obtained and demonstrated a communication between the joint and the cyst. The findings in these two patients support the synovial theory for intraneural ganglia. Based on their experience with intraneural ganglia at other sites, the authors believe that suprascapular intraneural ganglia arise from the glenohumeral joint, egress through a superior (posterior) labral tear, and dissect within the epineurium along an articular branch into the main nerve, following the path of least resistance. Furthermore, these two cases of intraneural ganglia with SLAP lesions are directly analogous to the many cases of paralabral cysts associated with these types of labral tears. By better understanding the origin of this unusual type of ganglia and drawing analogies to the more common extraneural cysts, surgical strategies can be formulated to address the underlying pathoanatomy, improve operative outcomes, and prevent recurrences.

Variants of the superior labrum and labro-bicipital complex: a comparative study of shoulder specimens using MR arthrography, multi-slice CT arthrography and anatomical dissection

The purpose of the present study was to evaluate the anatomical variability of the superior labrum and to compare the value of MR arthrography and multi-slice CT arthrography in the diagnosis of variants of the labro-bicipital complex. Forty-three human shoulder specimens (age range and mean age at death, 61-89 years and 78.3 years) were examined with the use of MR arthrography and multi-slice CT arthrography prior to joint exploration and macroscopic inspection of the superior labrum and labro-bicipital complex. Two radiologists evaluated MR and CT arthrograms, and the results were compared with macroscopic assessments. Anatomical dissection of all shoulder specimens revealed a sublabral recess in 32/43 (74%) cases. The attachment of the superior labrum was categorised as type 1 in ten (23%) cases, as type 2 in eight (19%), as type 3 in ten (23%), and as type 4 in 14 (33%) cases. One superior labrum showed detachment consistent with a superior labral anteroposterior (SLAP) type 3 lesion. On MR arthrography and CT arthrography the attachment of the superior labrum was categorised in concordance with macroscopic assessments in 79% and 84% of cases, respectively. The anteroposterior extension of sublabral recesses was accurately determined with MR and CT arthrography in 59% and 81% of cases, respectively. The attachment of the superior labrum shows considerable variability. Thus, exact depiction of variants is essential in order to avoid the false positive diagnosis of a superior labral tear (SLAP or Andrews lesion). Both, MR arthrography and multi-slice CT arthrography were effective in the detection and classification of sublabral recesses.

Diagnostic performance of MR arthrography in the assessment of superior labral anteroposterior lesions of the shoulder.

The purpose of this study was to evaluate the diagnostic performance of MR arthrography in the assessment of superior labral anteroposterior (SLAP) lesions of the shoulder with emphasis on the classification of SLAP lesions. Two hundred sixty-five MR arthrograms including 68 MR arthrograms of patients with arthroscopically proven SLAP lesions of the shoulder and 197 MR arthrograms of patients with an intact superior labrum and biceps anchor were retrospectively reviewed in random order. MR arthrography was performed using triplanar T1-weighted spin-echo sequences and a coronal oblique T2-weighted fast spin-echo sequence. MR arthrograms were evaluated by two radiologists with agreement by consensus, and the results were compared with arthroscopic findings. Of 68 SLAP lesions, seven (10%) were arthroscopically classified as type I, 41 (60%) as type II (including 20 type II lesions with coexisting Bankart lesions [29%]), 14 (21%) as type III, and six (9%) as type IV. Compared with arthroscopy as the gold standard, MR arthrography showed a sensitivity of 82% and a specificity of 98% for the overall detection of SLAP lesions. MR arthrographic grading and arthroscopic grading were concurrent in 45 (66%) of 68 arthroscopic diagnoses. Of the surgically confirmed SLAP lesions, involvement of the biceps insertion and SLAP type II lesions with coexisting Bankart lesions were assessed correctly in 75% and 95% of cases, respectively. MR arthrography is a highly effective method for the detection of SLAP lesions, but this technique is limited in the classification of different types of SLAP lesions. However, for preoperative planning MR arthrography provides accurate information about the stability of the biceps insertion and the presence of associated anteroinferior labral injuries.

Comparison of High-Field-Strength Versus Low-Field-Strength MRI of the Shoulder

Previous studies have reported similar results of shoulder MRI versus arthroscopy for high-field-strength (1.5-T) and low-field-strength (0.2-T) units. We report our experience with the accuracy of high- versus low-field-strength units versus arthroscopy for detection of supraspinatus tendon tears and labral tears in the same patients. SUBJECTS AND METHODS. Three musculoskeletal radiologists prospectively interpreted shoulder MRIs from 40 patients who had a complete shoulder MRI examination on a 0.2-T system and limited imaging on a 1.5-T unit. Proton-density axial and fat-saturated T2-weighted coronal and sagittal sequences were performed. Each radiologist interpreted the open unit images first and the high-field-strength images second. Results from 28 patients who also underwent arthroscopy were also compared with the MRI interpretations. All scans were then retrospectively reinterpreted by consensus of the three reviewers, who were unaware of the patient's name, results of previous MRI, or arthroscopy report (if any). High-field-strength images altered reviewers' interpretations of low-field-strength scans for nine of 40 patients. In four patients, full-thickness supraspinatus tendon tears could be diagnosed definitively on the high-field-strength unit but not on the open unit. Three labral tears and two superior labral anteroposterior lesions could be depicted definitively on the high-field-strength unit but not on the open unit. All tears were confirmed at arthroscopy. High-field-strength MRI units provide better spatial and contrast resolution and allow more accurate interpretations than low-field-strength units; these findings may affect clinical treatment.

The relationship of superior labralanteroposterior (SLAP) lesions and pseudolaxity to shoulder injuries in the overhead athlete

Understanding the effect of superior labral lesions on the function of the shoulder is essential to successfullytreating the overhead athlete. Recognizing the pseudolaxity owing to superior labral anteroposterior (SLAP) lesions and the pathological "peel-back" sign is critical in evaluating the injured shoulder in general and repairing the SLAP lesion in particular. The mechanical characteristics of suture anchors are more favorable than tacks in resisting the pathological forces responsible for the peel-back mechanism. The higher success rate of arthroscopic suture anchor repair of SLAP lesions in comparison with open capsulolabral reconstruction suggests that SLAP lesions are the usual cause of the "dead arm" syndrome. In our experience, arthroscopic repair of SLAP lesions can return the overhead athlete to their preoperative level of function in the vast majority of cases (87% return to preoperative level for two or more seasons).

Superior labral anteroposterior lesions: MR arthrography with arm traction.

The purpose of this study was to investigate the efficacy of arm traction combined with MR arthrography in the evaluation of superior labral anteroposterior (SLAP) lesions. Cadaveric shoulders were studied with a 1.5-T MR imaging unit with the arm externally rotated. Fifteen milliliters of a gadolinium-containing contrast agent were injected into the glenohumeral joint. Twenty-four sets of images of cadaveric joints were evaluated independently by two observers. These sets consisted of MR arthrographic images obtained with traction (applied to the wrist using 1- to 3-kg weights) and without traction in five shoulders in which SLAP lesions had been excluded arthroscopically or by cadaveric sectioning; and MR arthrographic images obtained with and without traction in seven shoulders in which various types of SLAP lesions had been created arthroscopically and later confirmed by cadaveric sectioning. Analysis of the data indicated that MR arthrography in combination with arm traction and external rotation improved diagnostic accuracy with regard to identification and categorization of SLAP lesions when compared with studies made without traction. The combination of MR arthrography and arm traction with the shoulder in external rotation provides a more effective approach for detection of SLAP lesions than does similar MR arthrography performed without arm traction.