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。     

Shoulder magnetic resonance imaging

MRI provides excellent soft tissue contrast and allows for multiplanar imaging in anatomic planes. Because of these advantages MRI has become the study of choice for imaging of shoulder pathology. Some structures, such as the rotator cuff, humeral head contour, and glenoid shape, are evaluated well with conventional MRI. When more sensitive evaluation of the labrum, capsule, articular cartilage, and glenohumeral ligaments is required or when a partial-thickness rotator cuff tear is suspected,magnetic resonance arthrography with intra-articular contrast can be performed. For MR arthrography contrast is injected directly into the glenohumeral joint. This article reviews the appearances of normal anatomic structures in MRI of the shoulder and disorders involving the rotator cuff and glenoid labrum.     

Shoulder instabilities. Radiological evaluation]

In case of anteromedial instability of the shoulder, the radiological investigation should start by comparative plain films including glenoid lateral views looking for a lesion of the anteroinferior glenoid margin of the scapula. If plain films are normal, CT arthrography of the shoulder is indicated looking for a lesion of the anteroinferior glenoid labrum. If no traumatic abnormality is present, a plain CT scan may sometimes show glenoid dysplasia, which is frequently bilateral. Posterior dislocation of the shoulder is less common and is obvious on plain films. The inventory of the lesions is established by CT arthrography. In case of multidirectional instability, the radiological investigation determines the preferential direction of instability, generally by means of dynamic manoeuvres.     

CT arthrography of capsular structures of the shoulder

The capsular mechanism of the shoulder joint consists of the joint capsule, which is strengthened by the glenohumeral ligaments and the rotator cuff, the glenoid labrum, and a variable number of synovial recesses. Although the fibrous capsule is a lax structure, the normal function of the capsular mechanism makes it an effective barrier against anterior dislocation, particularly in external rotation. There has been a tendency in the past to overestimate the role of the glenoid labrum in stability of the shoulder joint. In patients with instability, the significance of the capsular attachment or its anomalous insertions to the glenoid has not been adequately recognized. Labral tears may develop as secondary lesions due to repeated dislocations and subluxations rather than representing the primary lesion responsible for instability. Operative visualization of capsular defects or detachments is often difficult. Prior knowledge of these lesions can effectively help the choice of an appropriate surgical procedure and reduce operating time. The results of computed tomographic (CT) arthrography of the shoulder joint in 45 patients are reported and the normal and pathologic variations of the joint capsule and particularly the capsular insertions are described. Configuration of the joint recesses and the glenoid labrum are also evaluated. These CT findings were correlated and verified by surgery or arthroscopy in 26 cases.     

Glenoid labrum: preliminary work with use of radial-sequence MR imaging

The authors describe a magnetic resonance imaging method for examination of the glenoid labrum of the shoulder joint that utilizes a radial fast-imaging sequence. Seven shoulders were examined: a total of five in three healthy asymptomatic volunteers, one in a symptomatic patient not suspected of having a lesion of the glenoid labrum, and one in a patient with recurrent shoulder dislocation and surgical proof of an extensive tear of the labrum. The preliminary results suggest that this technique may advantageously demonstrate pathologic changes in the glenoid labrum and may contribute to the evaluation of the unstable and painful shoulder.     

Hypoplasia of the glenoid neck of the scapula: imaging findings and report of 16 patients

OBJECTIVE: Our purpose was to describe the primary and associated imaging findings in patients with glenoid hypoplasia required for an accurate diagnostic appraisal of this uncommon abnormality. METHODS: The medical records and imaging studies of 16 patients with glenoid hypoplasia were retrospectively reviewed. Plain films were available in all patients, arthrography in 2, computed tomography (CT) in 5, CT arthrotomography in 3, magnetic resonance (MR) imaging in 9, and MR arthrography in 3 patients. The imaging studies were reviewed with special attention to the primary and secondary findings associated with glenoid hypoplasia. RESULTS: On radiographs, the 21 abnormal shoulders documented in the 16 patients with glenoid hypoplasia had an irregular (n=15) or shallow and smooth (n=6) articular surface of the glenoid. Computed tomography findings showed subluxation of the humeral head in 5 cases. On MR images, the hypoplastic bony glenoid and scapular neck were replaced by abnormal tissue of inhomogeneous signal intensity, showing the signal intensity characteristics of fibrocartilage (n=6) or fat (n=5). Widening of the inferior glenohumeral joint space was seen in all cases. Magnetic resonance imaging or MR arthrography revealed variable abnormalities of the labrum, including enlargement (10 shoulders), detachment of labrum from the bony glenoid (6 shoulders), intrasubstance tear (4 shoulders), and perilabral cyst (2 shoulders). The posterior labrum was absent (n=1) or torn (n=1) in one patient with bilateral deformity. Other findings included partial tear of the subscapularis tendon (n=1) and rotator cuff atrophy (n=1) and tear (n=2). CONCLUSION: Glenoid hypoplasia is a developmental skeletal anomaly comprising a spectrum of associated osseous and cartilaginous changes of the articular cartilage and glenoid labrum. Cross-sectional imaging studies, with or without arthrography, may help further characterize associated derangements of the shoulder, some of which are indicative of shoulder instability.     

Glenoid labrum ossification and mechanical restriction of joint motion: extraosseous manifestations of melorheostosis

We report a case of a 47-year-old man who presented with progressive loss of motion and pain in the right shoulder. Radiographs of the shoulder demonstrated dense ossification in the glenoid and humeral head with extension into the periarticular soft tissues. CT and MRI scans confirmed the radiographic findings and also revealed ossification of the glenoid labrum. A radiographic diagnosis of melorheostosis, an uncommon benign sclerosing bone dysplasia, was made. Because of the patient’s severe symptomatology, he underwent total shoulder arthroplasty. Histological analysis of the resected masses was consistent with melorheostosis with a few areas covered by a cartilage cap. This case illustrates several uncommon but important features of melorheostosis, including mechanical obstruction of joint motion requiring joint replacement, ossification of the glenoid labrum, and cartilage-covering portions of the intra-articular masses, not to be confused with cartilage-producing tumors. Presented at the 34th members meeting of the International Skeletal Society, Budapest, Hungary, October 2007.     

Glenohumeral instability associated with Buford complex

Buford complex is described as a normal anatomical variant of the anterosuperior part of the glenoid consisting of the absence of the anterosuperior labrum with the presence of a cord-like middle glenohumeral ligament. Traditionally, reattachment to the glenoid has been discouraged. We present a case of a Buford complex associated with glenohumeral instability. The patient was operated for recurrent instability without a preoperative diagnosis of Buford complex. The diagnosis was made during shoulder arthroscopy and reattachment to the glenoid was performed with a satisfactory outcome. Here, we discuss the relationship of the Buford complex with intraarticular pathology and the surgical treatment in cases when this variant is associated with instability.     

Computerized tomography imaging of shoulder joint injuries

In addition to conventional radiography using standard and special projections, CT offers valuable information in selected cases. Native CT allows detection of minimal bony lesions, which may cause severe pain that is resistant to therapy. Small amounts of joint effusion as well as the Hill-Sachs impression fracture of the humeral head can be detected with a high degree of accuracy. Following intra-articular injection of contrast medium, CT-arthrography enables visualization of capsular and ligamentous injuries of the shoulder joint. Lesions of the glenoid labrum following shoulder dislocation can be detected and classified by this method.     

Glenoid labrum tears related to the long head of the biceps

Tears of the glenoid labrum were observed in 73 baseball pitchers and other throwing athletes who underwent arthroscopic examination of the dominant shoulder. Most of the tears were located over the anterosuperior portion of the glenoid labrum near the origin of the tendon of the long head of the biceps muscle into the glenoid. At arthroscopy, the tendon of the long head of the biceps appeared to originate through and be continuous with the superior portion of the glenoid labrum. In many cases it appeared to have pulled the anterosuperior portion of the labrum off the glenoid. This observation was verified at arthroscopy by viewing the origin of the biceps tendon into the glenoid labrum as the muscle was electrically stimulated. With stimulation of the muscle, the tendinous portion became quite taut, particularly near its attachment to the glenoid labrum, and actually lifted the labrum off the glenoid. Three-dimensional high-speed cinematography with computer analysis revealed that the moment acting about the elbow joint to extend the joint through an arc of about 50 degrees was in excess of 600 inch-pounds. The extremely high velocity of elbow extension which is generated must be decelerated through the final 30 degrees of elbow extension. Of the muscles of the arm that provide the large deceleration forces in the follow-through phase of throwing, only the biceps brachii traverses both the elbow joint and the shoulder joint. Additional forces are generated in the biceps tendon in its function as a "shunt" muscle to stabilize the glenohumeral joint during the throwing act.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased risk of posterior glenoid labrum tears in football players

OBJECTIVE: This study was designed to test our hypothesis that football players with shoulder pain, shoulder instability, or both requiring MR arthrography for evaluation are at an increased likelihood relative to non-football players for having a tear of the posterior glenoid labrum. CONCLUSION: We conclude that posterior glenoid labrum tears are more prevalent in football players than in non-football players.     

Superior labrum anterior posterior lesions of the shoulder: Operative techniques of management

Since the advent of shoulder arthroscopy, pathology of the superior glenoid labrum and biceps anchor has been increasingly recognized as a source of shoulder pain and disability. Additional biomechanical testing has substantiated the role of the superior labrum and biceps anchor in glenohumeral stability. The diagnosis of superior labral injury such as the superior labrum anterior posterior (SLAP) lesion remains difficult, as the history, clinical examination, and radiographic evaluation can only raise suspicion. The ultimate diagnosis of the SLAP lesion can only be made with a well-directed diagnostic glenohumeral arthroscopy. The treatment of SLAP lesions depends on the type of SLAP lesion encountered at arthroscopy. This includes debridement of most type I and III lesions, and repair of type II and many type IV SLAP lesions. In this report, we will present our basic approach towards evaluation and treatment of SLAP lesions at the Southern California Orthopedic Institute.     

CT and MR evaluation of the labral capsular ligamentous complex of the shoulder.

Stability of the glenohumeral articulation is dependent on the integrity of the rotator cuff, labrum, glenohumeral ligaments, capsular elements, and bony glenoid. The importance of the soft-tissue elements in maintaining stability has been well documented in the surgical literature but has only recently been introduced into the radiologic literature. The purpose of this essay is to illustrate the normal labrum, capsular complex, and glenohumeral ligaments, including common congenital variations as depicted by CT arthrography and MR imaging, and to describe the pathologic findings leading to shoulder instability.     

肩关节MR造影对肩关节前方盂唇病变的诊断价值

目的明确肩关节造影MR对肩关节前方盂唇病变的诊断价值，并比较中立位肩关节造影MR和外展外旋（abduction and external rotation, ABER）造影MR的价值。方法回顾性分析经证实的44例肩关节造影MR资料，以肩关节镜检查结果为金标准，对比中立位肩关节造影MR和ABER造影MR对肩关节前方盂唇病变的诊断价值。结果中立位肩关节造影MR对前方盂唇的诊断敏感度为79．3％（23／29），特异度为100％（15／15），准确度为86．4％（38／44）；ABER造影MR的敏感度为93．1％（27／29），特异度为100％（15／15），准确度为95．5％（42／44）。ABER造影MR显著提高了前方盂唇病变的诊断敏感度（P=0．037）。结论ABER造影MR可以提高肩关节前方盂唇病变的诊断敏感度。     

Normal anatomy and common labral lesions at MR arthrography of the shoulder

MR arthrography of the shoulder is the most accurate imaging modality in demonstrating abnormalities of the glenoid labrum and associated structures. Tears of the labrum, the capsule or the gleno-humeral ligaments can lead to pain, catching, popping or instability. The anatomy of this region is complex. We present the normal anatomy of the glenoid labrum, biceps anchor and gleno-humeral ligaments together with their normal variants and then describe common labral-ligamentous pathologies.     

Magnetic resonance imaging of the glenoid labrum

Shoulder complaints are common in the athletic population. Successful treatment is dependent upon the ability to correctly identify the pathologic changes associated with a specific disorder and arrive at an accurate diagnosis. Labral abnormalities are traditionally associated with glenohumeral instability. Isolated labral tears or degenerative changes may also cause shoulder dysfunction. A reliable clinical tool to assess the status of the labrum would be useful for diagnosis and management of shoulder disorders. The magnetic resonance images of 48 shoulders that had subsequent surgical examination of their labra were reviewed with respect to labral appearance. Labra appearing as abnormal were further classified as torn, degenerative, or eroded. Surgical examination was used as the reference standard. Magnetic resonance imaging demonstrated high levels of sensitivity, specificity, positive and negative predictive values, and accuracy for evaluation of the glenoid labrum. Magnetic resonance imaging is a reliable and accurate method for depicting the status of the glenoid labrum. Magnetic resonance imaging appearance of the labrum may assist the clinician in distinguishing the varying forms of shoulder dysfunction and facilitate diagnosis and effective treatment.     

Antero-posterior lesions of the superior glenoid labrum. Magnetic resonance evaluation

PURPOSE: To assess MR potentials in the evaluation of superior glenoid labrum disease and possible associated conditions of the rotator cuff and of the anterior mechanism of the shoulder. MATERIAL AND METHODS: We retrospectively evaluated 51 patients (age range 18 to 53 years) with a diagnosis of anteroposterior lesion of the superior glenoid labrum. MR examinations were performed with a 0.2 T permanent magnet and a dedicated coil, using T1- and T2-weighted SE sequences on mostly coronal-oblique planes. Slice thickness was 4 mm. In 8 cases, the examination was completed with intra-articular injection of contrast agent. Twenty-eight patients were submitted to surgery (arthrotomy in 7 cases; arthroscopy in 21 cases). RESULTS: We considered only the cases with surgical confirmation and divided them into 2 groups: 15 patients with isolated alteration of the superior glenoid labrum and 13 patients with an anteroposterior lesion of the glenoid labrum associated with disease of the rotator cuff or of the anterior mechanism of the shoulder. MRI demonstrated 5 cases of superior labrum irregularities at the level of its glenoid insertional portion (type I lesion); 6 cases of detachment of the superior portion of the labrum (type II); 9 cases of bucket handle tear of the superior labrum with involvement of the insertional portion of the long head of the biceps tendon (type III); 8 cases of superior labrum tear extending within the long head of the biceps tendon (type IV). In the patients with associated disease MRI demonstrated supraspinatus tendon tear in 5 cases, lesion of the labrum also in its anteroinferior portion in 1 case, Hill-Sachs intraspongious fracture with involvement of the inferior glenohumeral complex in 1 case, and complete tear of the rotator cuff in 7 cases. Subsequent surgery always confirmed the presence of associated lesions, while the superior labrum lesion was not confirmed in 3 patients. In 4 cases, surgical findings provided a different classification of the lesion type than MRI. DISCUSSION: In the presence of a type I anteroposterior lesion of the superior glenoid labrum, coronal MRI can depict the loss of the triangular shape of the labrum. Type II lesions show detachment of the labrum, which appears on the MR images as a high signal intensity band passing through the labrum with caudocranial orientation. A superior glenoid labrum tear with a low signal intensity area within the joint indicates a type III lesion. Complete tear of the superior glenoid labrum with involvement of the long head of the biceps tendon demonstrated on the coronal T1-weighted SE and T2-weighted GE sequences is a sign of a type IV lesion. CONCLUSIONS: MRI can be a valuable diagnostic technique in type III and IV lesions of the superior glenoid labrum. It often provides important information about the possible presence of associated diseases, especially of the rotator cuff, which are helpful for treatment planning.     

MR imaging of recurrent anterior dislocation of the shoulder: comparison with CT arthrography

Posttrauma damage due to anterior glenohumeral joint dislocation may result in recurrent dislocation. Currently CT arthrography is the method of choice to evaluate the extent of osseous and soft-tissue changes before reconstructive surgery. This study was undertaken to determine if MR was able to depict postdislocation abnormalities and if MR is a possible replacement for CT arthrography. Thirteen patients with recurrent anterior shoulder dislocation were evaluated with conventional radiography and MR; CT arthrography was performed in 10. Twelve patients underwent surgery, and the findings of MR and CT arthrography were verified. MR and CT arthrography showed the integrity of the glenoid labrum equally well. All humeral head defects, detected in nine patients with plain film radiography and CT, were easily identified with MR. Information about anterior joint capsule abnormalities is difficult to obtain with MR. However, separation of the capsule from the bony glenoid can be detected if a joint effusion is present to adequately distend the joint. Preliminary results of this study indicate that MR is useful in the assessment of postdislocation abnormalities and may possibly replace CT arthrography in the evaluation of patients with recurrent shoulder dislocation.     

Shoulder biomechanics

The biomechanics of the glenohumeral joint depend on the interaction of both static and dynamic-stabilizing structures. Static stabilizers include the bony anatomy, negative intra-articular pressure, the glenoid labrum, and the glenohumeral ligaments along with the joint capsule. The dynamic-stabilizing structures include the rotator cuff muscles and the other muscular structures surrounding the shoulder joint. The combined effect of these stabilizers is to support the multiple degrees of motion within the glenohumeral joint. The goal of this article is to review how these structures interact to provide optimal stability and how failure of some of these mechanisms can lead to shoulder joint pathology.     

The Bankart repair illustrated in cross-section. Some anatomical considerations

The Bankart repair for chronic anterior shoulder instability effectively addresses the pathologic components responsible for repeated dislocation or subluxation. However, contrary to popular belief, the Bankart repair does not precisely restore the premorbid anatomy. The capsule is reattached to the boney rim of the anterioinferior glenoid deep to and lateral to the torn cartilagenous labrum, thus excluding the labrum from the joint anteriorly. This was demonstrated by cross-sectional cadaver dissections performed to illustrate this complex surgical anatomy to orthopaedic residents in training. In addition, when correlated with double-contrast computerized axial tomography, we noted five predominant patterns of anatomical lesions which by common use have been collectively termed the "Bankart lesion." These are: 1) the rare "classic" Bankart lesion in which the cartilagenous labrum and capsular origin are torn from the glenoid rim; 2) the capsule stripped from the scapular neck and the labrum detached from the glenoid rim remaining fixed to the overlying capsule; 3) the capsule stripped from the scapular neck and the labrum separated from the glenoid rim, but separately; 4) the labrum abraded away and no longer radiographically detectable; and 5) glenoid rim fracture.