Athlete shoulder injuries: CT arthrographic findings

Forty-three professional and amateur athletes with persistent shoulder pain that interfered with their sports activities were evaluated by computed tomographic (CT) arthrography. In 19 patients, glenohumeral instability (14 anterior, two posterior, three multidirectional) was diagnosed with CT arthrography based on the simultaneous presence of labral and capsular lesions. The findings were crucial in establishing the diagnosis of instability in six patients in whom the condition was not suggested or could not be confirmed clinically. Another significant injury consisted of labral lesions not associated with glenohumeral instability. These tears often involved the anterior and parasuperior segments of this structure. Other, less frequently detected lesions included segmental labral enlargement and several labra with abnormal orientation (everted labrum). Early onset of degenerative disease was present in many athletes, especially those with a long history of sports activity. CT arthrographic findings were correlated with arthroscopic or surgical results in 19 patients.     

Shoulder MR arthrography: which patient group benefits most?

OBJECTIVE: We sought to compare the diagnostic accuracy of conventional MRI versus MR arthrography of the shoulder in the assessment of high-performance athletes (professional baseball players) and to compare our findings in these patients with the conventional MRI and MR arthrographic findings in an age-matched control group of nonprofessional athletes. MATERIALS AND METHODS: Conventional MRI and MR arthrographic examinations of the shoulder in 20 consecutive professional baseball players with shoulder pain were reviewed retrospectively by two musculoskeletal radiologists in consensus. These interpretations were compared with retrospective consensus interpretations of conventional MRI and MR arthrographic examinations of the shoulder obtained in a control group of 50 consecutive nonprofessional athletes with shoulder pain. MR images were assessed for full- or partial-thickness supraspinatus tendon tears, superior labral anteroposterior (SLAP) tears, and anterior or posterior labral tears. RESULTS: In the 20 consecutive professional athlete patients, two full-thickness and six partial-thickness undersurface supraspinatus tendon tears were seen on MR arthrography but not seen on conventional MRI as well as six SLAP tears, two anterior labral tears, and one posterior labral tear. Three patients had both SLAP tears and full- or partial-thickness supraspinatus tendon tears. Of 14 patients with findings on MR arthrography that were not seen on MRI, 11 had arthroscopic correlation. In all 11, arthroscopic findings confirmed findings on MR arthrography. In the group of 50 nonprofessional athlete patients, five had additional findings on MR arthrography not seen on conventional MRI: two anterior labral tears, two partial-thickness supraspinatus tendon tears, and two SLAP tears. One patient had both a partial-thickness supraspinatus tendon tear and a SLAP tear seen on MR arthrography. The five patients with additional findings on MR arthrography had arthroscopy. In all five, arthroscopic findings confirmed the findings on MR arthrography. CONCLUSION: MR arthrography is considerably more sensitive for detection of partial-thickness supraspinatus tears and labral tears than conventional MRI. MR arthrography showed injuries in addition to those seen on conventional MRI in 14 of 20 patients in the high-performance athlete group. These results suggest high-performance athletes may be a subgroup of patients for whom MR arthrography yields considerably more diagnostic information than conventional MRI.     

Capsulo-labro-ligamentous lesions of the shoulder: evaluation with MR arthrography

PURPOSE: The aim of the study was to analyse the accuracy of MR arthrography in the evaluation of capsulo-labro-ligamentous lesions of the shoulder in patients with glenohumeral joint instability. MATERIALS AND METHODS: From 1999 to 2001 fifty-eight patients with glenohumeral joint instability were studied by MR arthrography. Twenty-seven patients underwent surgical repair: 11 by arthroscopic and 16 by arthrotomic approach. All shoulder evaluations were performed with T1 and T2 weighted axial, coronal and sagittal oblique images, before and after intra-articular injection of gadolinium contrast. RESULTS: Forty capsulo-ligamentous lesions (including 14 capsular ruptures with extravasation of the contrast medium) were detected by MR arthrography. Fifty-two labral tears (36 of the anterior, 13 of the superior and 3 of the posterior glenoid labrum) were identified: 11 out of 52 were not recognized before gadolinium contrast injection. Five rotator cuff tears were identified, one of which was not shown in the pre-injection examination. Surgical results confirmed the MR arthrographic findings in 25/27 patients. In one case MR arthrography did not recognize a SLAP lesion; in another case it identified a tear of the capsule but not of the glenoid labrum. CONCLUSIONS: In many cases of subacute glenohumeral joint lesions with intracapsular fluid, MR may accurately evaluate capsulo-labral-ligamentous lesions. Indeed, the examination of lesions is limited by the absence of the natural contrast determined by fluid; in such cases, intra-articular injection of gadolinium contrast is necessary. MR arthrography evaluates the degree of capsulo-labro-ligamentous tears and may guide the surgical approach.     

CT空气—碘水双对比造影对肩关节不稳定诊断的意义

目的：探讨ＣＴ空气－碘水双对比造影对诊断肩关节不稳定的临床意义。材料与方法：８例患者做肩前穿刺，分别注入７６％泛影葡胺４ｍｌ和过滤空气１０ｍｌ，在全身ＣＴ机上行肩关节扫描。结果：所有患者气－碘双对比造影ＣＴ表现均与术中所见一致。主要特征为：（１）盂唇前部变钝、撕脱、游离；（２）关节囊前部撕脱或者关节囊破裂；（３）关节囊松弛、囊腔扩大。结论：ＣＴ气－碘双对比造影可以明确诊断肩关节不稳定，并为肩关节不稳定的解剖修复提供重要的影像学信息。     

A new pain provocation test for superior labral tears of the shoulder

We prospectively evaluated the usefulness of a new pain provocation test to diagnose superior labral tears in 32 patients with diagnosed throwing injuries of the shoulder. Results of the pain provocation test were compared with findings on magnetic resonance arthrography (all 32 patients) and arthroscopic examination (15 patients). In 22 patients, detachment of the superior labrum was observed on arthrograms, and all of them had positive results on the new pain provocation test. Nine of the other 10 patients had negative results on the new pain provocation test. However, 1 of the 10 patients had a positive result. Eleven of 15 patients were found to have superior labral lesions arthroscopically, and all of them were classified as type II superior labral anterior posterior lesions. All the 11 patients had positive pain provocation tests. The other four patients without superior labral tears on arthroscopic findings had negative results on the new pain provocation test. The new pain provocation test identified all patients with detachment of the superior labrum confirmed by magnetic resonance arthrography, for a sensitivity of 100%, a specificity of 90%, and an accuracy of 97%. Results of the new pain provocation test were in accord with arthroscopic findings in the 15 patients who underwent arthroscopic examination.     

Shoulder arthroscopy: its role in evaluating shoulder disorders in the athlete

We retrospectively reviewed 100 initial shoulder arthroscopies from a general sports medicine orthopaedic practice to determine if arthroscopy is helpful diagnostically and to see if specific lesions correlate well with specific diagnoses. Seventy-two percent of the patients in the review had glenoid labral tears. Ninety-two percent of patients who had a diagnosis of either recurrent anterior dislocation or recurrent anterior subluxation demonstrated a tear of the anterior inferior margin of the glenoid labrum. Sixty-eight percent of patients with a diagnosis of impingement demonstrated tears at the superior margin of the labrum. There was a significant difference between throwing and nonthrowing athletes. Partial rotator cuff tears were noted in 18 patients, the majority occurring in throwing athletes. Other abnormalities, such as degenerative joint changes and biceps tendon lesions, were also noted at the time of arthroscopy. A large number of glenoid labral tears found at the time of arthroscopy appeared to be associated with conditions other than instability, which may or may not affect the throwing athlete. There also appeared to be a high correlation between tears in the anterior inferior glenoid labrum and anterior instability. Arthroscopy enabled us to identify other significant information about the status of the biceps tendon or the undersurface of the rotator cuff. These are areas in which problems might otherwise have been missed. Degenerative changes of the articular surface, not apparent on plain radiographs, may also be better evaluated arthroscopically.     

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability.Magnetic resonance (MR) imaging,and more recently,MR arthrography,have become the essential investigation modalities of glenohumeral instability,especially for pre-procedure evaluation before arthroscopic surgery.Injuries associated with glenohumeral instability are variable,and can involve the bones,the labor-ligamentous components,or the rotator cuff.Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament,in the form of Bankart lesion and its variants;whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion.Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion.This article reviews the relevant anatomy in brief,the MR imaging technique and the arthrographic technique,and describes the MR findings in each type of instability as well as common imaging pitfalls.     

MR arthrography of the shoulder: comparison with conventional MR imaging

Twenty-three patients underwent both conventional MR imaging of the shoulder and MR shoulder arthrography for clinically suspected labral or rotator cuff abnormalities. Images obtained before and after contrast administration were studied independently, and without knowledge of clinical findings, by two radiologists for the presence of abnormalities of the glenoid labrum or rotator cuff. Results were correlated with surgical findings in all patients. Nine patients had surgically proved labral tears. MR arthrography detected all nine labral abnormalities, while six of the nine were missed on conventional MR imaging. Fourteen patients had surgically proved rotator cuff tears. MR arthrography detected 11 of the 14 tears and missed three partial tears on the bursal surface. Conventional MR imaging detected nine cuff tears and missed five tears; two of these were complete rotator cuff tears and three were partial tears of the undersurface of the rotator cuff. Our results suggest that MR arthrography enhances the accuracy of MR in the evaluation of the glenoid labrum and rotator cuff tendon.     

SLAP lesions: anatomy, clinical presentation, MR imaging diagnosis and characterization

Superior labral anterior posterior (SLAP) tears are an abnormality of the superior labrum usually centered on the attachment of the long head of the biceps tendon. Tears are commonly caused by repetitive overhead motion or fall on an outstretched arm. SLAP lesions can lead to shoulder pain and instability. Clinical diagnosis is difficult thus imaging plays a key diagnostic role. The normal anatomic variability of the capsulolabral complex can make SLAP lesions a diagnostic challenge. Concurrent shoulder injuries are often present including rotator cuff tears, cystic changes or marrow edema in the humeral head, capsular laxity, Hill-Sachs or Bankart lesion. The relevant anatomy, capsulolabral anatomic variants, primary and secondary findings of SLAP tears including MR arthrography findings, types of SLAP lesions and a practical approach to labral lesions are reviewed.     

Arthroscopic assessment of the unstable shoulder

The purpose of this study was to evaluate prospectively the findings during shoulder arthroscopy in patients with recurrent anterior instability of the gleno-humeral joint. One hundred and seventy-eight patietns who fulfilled the criteria of having had at least one documented shoulder dislocation were included in the study. The pathological findings most frequently noted at arthroscopy were: anterior glenoid labral tears (85%), ventral capsule insufficiency (80%), Hill-Sachs compression fractures (67%), glenohumeral ligament insufficiency (55%), rotator cuff tears (20%), posterior glenoid labral tears (8%), and SLAP lesions (5%). Abnormalities were noted more frequently than expected, and there were significant differences between preoperative and postoperative diagnoses. Our study has taught us that a mulitplicity of morphological changes are associated with instability of the glenohumeral joint, and that there is no single cause. The labrum and rim of the anterior inferior glenoid, for instance, showed typical abnormalities corresponding to different entities of anterior instability. In practice, this is very important, as the abnormalities visualized by imaging methods determine the surgical treatment.     

SLAP lesions of the glenoid labrum: CT arthrographic and arthroscopic correlation.

Tears in the superior part of the glenoid labrum in the anterior and posterior directions (SLAP, superior labrum anterior, posterior) result from injuries that place excessive stress on the tendon of the long head of the biceps brachii muscle. The intimate relationship of the tendon and the superior glenoid labrum promotes injury to the latter structure. Four types of SLAP lesions are seen at arthroscopy. Images from 17 patients with surgically proved SLAP lesions who had undergone preoperative computed tomographic (CT) arthrography were retrospectively reviewed to evaluate the value of CT arthrography in the detection and accurate depiction of these labral injuries. The authors compared the findings at videotaped arthroscopic surgery with those from CT arthrography and found that abnormalities of the labral-capsular apparatus could be detected with CT arthrography in 16 of the 17 patients. Furthermore, the CT arthrographic criteria developed during this review helped determine the type of tear in 15 of the 17 patients. CT arthrography appears to be useful in the evaluation of patients with suspected SLAP lesions.     

A prospective comparison study of double contrast computed tomography (CT) arthrography and arthroscopy of the shoulder

Thirty consecutive patients who underwent double contrast CT arthrography prior to shoulder arthroscopy were prospectively studied. Results from both studies were recorded with the radiologist blinded to the arthroscopic findings when making the final CT reading. The sensitivity, specificity, and accuracy, respectively, of CT arthrography findings compared to arthroscopy were 50%, 100%, 96% for rotator cuff; 66%, 100% 96% for bicipital labral complex; 100%, 100%, 100% for loose bodies; 50%, 100% 93% for Hill-Sachs lesions; 90%, 73%, 83% for anterior labral defects; and 100%, 100%, 100% for posterior labral defects. We conclude that shoulder arthroscopy accurately delineates abnormalities of the anterior and posterior labrum, bicipital labral complex, rotator cuff, joint synovium, and humeral head. CT arthrography accurately delineates capsular redundancy, loose bodies, hardware around joints, and bony glenoid rim abnormalities.     

Role of us in the preoperative evaluation of patients with anterior shoulder instability

PURPOSE: To assess the value of ultrasonography (US) in the preoperative evaluation of patients with anterior shoulder instability. MATERIALS AND METHODS: Twenty-two patients with one-sided anterior shoulder instability were examined with US by using three dynamic scanning approaches: two frontal and one axillary. The anterior labrum, the anterior ligamental-capsular complex, and the presence of humeral head and glenoid rim fractures were evaluated. Arthroscopy or arthrotomy was subsequently performed in all patients and was considered the standard. RESULTS: US correctly depicted the presence (n = 20) or absence (n = 1) of humeral head fractures and the presence (n = 10) or absence (n = 9) of glenoid rim fractures. All 22 patients had anterior labral tears; 21 tears were correctly depicted with US. The labral tear was seen as a hypoechoic zone larger than 2 mm (n = 15), labral movement (n = 10), a degenerated labrum (n = 6), or a vacuum phenomenon (n = 3). The anterior ligamental-capsular complex was correctly evaluated in 14 patients. The use of multiple approaches helped to prevent misinterpretation, but there were no substantial differences among the approaches in the depiction of the anterior shoulder structures. CONCLUSION: The high accuracy in the depiction of labral tears and associated fractures indicates that US can provide useful preoperative information in patients with anterior shoulder instability.     

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.     

Double-contrast computed tomography of the glenoid labrum

Imaging of glenoid labrum pathology is useful to help plan surgical repair of the dislocating shoulder. Eleven patients with suspect labrum damage were imaged with computed tomography (CT) immediately after routine double-contrast shoulder arthrography. Lesions identified included attenuation, tears, and displacement of the labrum as well as stripping and stretching of the anterior shoulder joint capsule. Surgical confirmation of pathology was available in all but one case. CT of the glenoid labrum is easy to perform, low in radiation dose, and accurate.     

Evaluation of glenoid labrum by double-contrast shoulder arthrography.

Double-contrast shoulder arthrography was used to define the normal and abnormal arthrographic anatomy of the glenoid labrum. A retrospective study of 12 patients suspected of having labral abnormalities or who had unexplained shoulder disability consistent with capsular laxity was undertaken. In four of the nine patients with abnormal arthrograms, the study revealed critical anatomic alterations not detectable on physical examination or pain radiographs.     

MR arthrographic assessment of suspected posteroinferior labral lesions using flexion, adduction, and internal rotation positioning of the arm: preliminary experience

Objective

Imaging the shoulder in the position of flexion, adduction, and internal rotation (FADIR) may be useful in characterizing lesions of the posteroinferior labrum. The purpose of this preliminary study is to illustrate the diagnostic utility of FADIR positioning in the assessment and characterization of posteroinferior labral tears.

Materials and Methods

In the FADIR position, the arm is placed across the chest, with the hand on the contralateral shoulder and palm facing outwards. FADIR positioning was performed if there was a subtle or equivocal abnormality of the posteroinferior labrum on conventional MR arthrography sequences. A retrospective review of the charts of 9 people who were imaged using FADIR positioning in addition to routine MR arthrographic sequences of the shoulder was performed. The review included the indication for the study, documentation of presence of clinical posterior instability, and surgical correlation, where available.

Results

In all 9 patients, FADIR positioning helped confirm, exclude, or better characterize a posteroinferior labral abnormality by increasing the diagnostic confidence.

Conclusion

Flexion, adduction, and internal rotation positioning appears to be a useful adjunct in evaluating patients with equivocal or subtle posteroinferior labral abnormalities on conventional MR arthrography sequences.     

Schultergelenkinstabilität

Shoulder instability is a common clinical feature leading to recurrent pain and limited range of motion within the glenohumeral joint. Instability can be due a single traumatic event, general joint laxity or repeated episodes of microtrauma. Differentiation between traumatic and atraumatic forms of shoulder instability requires careful history and a systemic clinical examination. Shoulder laxity has to be differentiated from true instability followed by the clinical assessment of direction and degree of glenohumeral translation.Conventional radiography and CT are used for the diagnosis of bony lesions. MR imaging and MR arthrography help in the detection of soft tissue affection, especially of the glenoid labrum and the capsuloligamentous complex.The most common lesion involving the labrum is the anterior labral tear, associated with capsuloperiostal stripping (Bankart lesion). A number of variants of the Bankart lesion have been described, such as ALPSA, SLAP or HAGL lesions.The purpose of this review is to highlight different forms of shoulder instability and its associated radiological findings with a focus on MR imaging.     

MR arthrography of the posterior labrocapsular complex: relationship with glenohumeral joint alignment and clinical posterior instability

OBJECTIVE: The purpose of our study was to investigate the relationship between tears of the posterior labrocapsular complex and glenohumeral alignment on MR arthrography and the presence and extent of posterior labrocapsular tears in patients with posterior instability. MATERIALS AND METHODS: Posterior labrocapsular tears identified on 24 MR arthrograms and surgically confirmed were evaluated for length of tear and labrocapsular avulsion. These examinations and a comparison cohort of 70 normal MR arthrograms with normal findings were also evaluated for humeral head position relative to the glenoid fossa. Medical records were reviewed for clinical diagnosis of posterior instability and history of shoulder trauma. RESULTS: The position of the humeral head relative to the glenoid was significantly more posterior in patients with posterior labral tear than in patients with a normal posterior labrum (4.9 mm versus 0.7 mm; p < 0.0001). The mean length (+/- SD) of posterior labral tear was 15.9 +/- 1.7 mm, and a direct correlation was found between tear length and posterior humeral translation (r = -0.65; p = 0.002). Posterior labral tears were significantly longer (18.6 vs 13.1 mm; p = 0.04), and posterior humeral translation was greater (6.4 vs 3.4 mm; p = 0.006) in patients with labrocapsular avulsion than in those without avulsion. Twelve (50%) of the patients with posterior labrocapsular tear had posterior instability, and 10 (83%) had a history of macrotrauma. On MR arthrography, the mean posterior humeral translation was greater (6.2 mm +/- 0.08; p = 0.019), posterior labral tears were longer (19.4 mm +/- 1.7; p = 0.0008), and labrocapsular avulsion was more common (83%; p = 0.0001) in patients with posterior instability than in patients who had a posterior labral tear but a clinically stable shoulder. CONCLUSION: Clinical posterior instability is associated with excessive posterior humeral translation, long posterior labral tears, and posterior labrocapsular avulsion.     

Anomalies of the long head of the biceps brachii tendon: clinical significance,MR arthrographic findings,and arthroscopic correlation in two patients

Two patients with clinically relevant anomalies of the long head of the biceps brachii tendon (LHBT) are presented with MR arthrography and surgical correlation. Such variations in the LHBT can mimic tears of the tendon itself or the adjacent superior labrum both on MR arthrography and at surgery. MR arthrographic features are recognizable and allow for correct prospective diagnosis, possibly averting unnecessary surgery. Although further study is needed, patients with these anomalies may be at increased risk for developing shoulder instability.