Magnetic resonance imaging versus arthroscopy for the investigation of the osteochondral humeral defect in anterior shoulder instability

A double-blind prospective study was done with 15 patients with anterior shoulder instability to determine the diagnostic efficacy of magnetic resonance (MR) imaging versus arthroscopy in the evaluation of chondral or osteochondral lesions of the humeral head. MR produced 6 true positives, 5 true negatives and 4 false negatives, and its accuracy and sensitivity were 60% and 87%, respectively, whereas arthroscopy gave 8 true positives, 5 true negatives and 2 false negatives, with a sensitivity of 80% and an accuracy of 87%. All lesions diagnosed with either method were regarded as positive by definition, with the result that the specificity was always 100%. The differences in diagnosis sprang from the false negatives. The 40% discrepancy between the two methods was probbly due to our distinction in MR between intra- and extraarticular osteochondral lesions. In the first group (the 4 MR false negatives), there were three instances of firstdegree intra-articular lesion and one diagnostic error (third-degree lesion). In the second (the 2 arthroscopy false negatives), the lesions were of the extra-articular type. It is thus advisable to employ both of these methods to ensure the correct diagnosis of a Hill-Sachs lesion, and hence the correct choice of treatment.     

MR-arthrography in superior instability of the shoulder: correlation with arthroscopy

Purpose

This study was undertaken to evaluate magnetic resonance (MR) arthrography in the detection and classification of lesions that may cause superior instability.

Materials and methods

Forty-two consecutive patients with clinical signs of chronic superior instability of the shoulder underwent MR arthrography followed by arthroscopic surgery. For each patient we retrospectively reviewed the MR arthrography and surgical findings.

Results

We detected 31 superior labral anterior posterior (SLAP) lesions, all confirmed on arthroscopy with three cases of underestimation: in the detection of SLAP lesions, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of MR arthrography were 100%; in the evaluation of the type of SLAP lesion, sensitivity was 100%, specificity was 78.5%, accuracy was 92.8%, PPV was 71.7% and NPV was 100%. All cases of capsular laxity (13/42) and biceps tendon lesions (3/42) were confirmed on arthroscopy with sensitivity, specificity, accuracy, PPV and NPV of 100%. Eleven cuff lesions were detected on MR arthrography, 10 of which confirmed at arthroscopy: sensitivity was 100%, specificity was 96.8%, accuracy was 97.6%, PPV was 90.9% and NPV was 100%. Associated lesions were found in 38/42 patients.

Conclusions

Superior instability is frequently associated with different anatomical variants or pathological conditions, such as SLAP lesions. The role of MR arthrography is to describe the key features of lesions affecting the superior portion of the shoulder, including location, morphology, extent, and associated injuries and leanatomical variants and to correlate these features with clinical symptoms.     

肩关节损伤的MR影像诊断

目的 探讨常规MRI和MR间接关节造影对肩关节损伤的诊断价值.方法 回顾分析经关节镜证实的90例肩关节损伤患者肩关节常规MRI和MR问接关节造影表现,其中肩袖病变组57例、盂肱关节不稳组33例.对常规MRI和MR间接关节造影诊断结果进行Fisher确切概率法比较.结果 (1)肩袖病变组中MR间接关节造影37例,显示部分撕裂10例,1例漏诊;显示完全撕裂17例,2例误诊,7例肩袖无撕裂.MR间接关节造影显示部分撕裂的敏感度、特异度、准确度分别为90.9%(10/11)、92.3%(24/26)、91.9%(34/37);显示完全撕裂的敏感度、特异度、准确度分别为89.5%(17/19)、94.4%(17/18)、91.9%(34/37).MR间接关节造影诊断肩袖部分及完全撕裂的敏感度及准确度均高于常规MRI(P<0.05).(2)盂肱关节不稳组中,盂唇损伤26例,Hill-sachs病变27例、反Hill-sachs病变2例、骨陛Bankart损伤7例、关节囊损伤18例.间接关节造影20例,显示盂唇损伤14例,1例漏诊,5例正常.MR间接关节造影显示盂唇损伤的敏感度、特异度、准确度分别为93.3%(14/15)、100.0%(5/5)、95.0%(19/20).前者诊断盂唇损伤的敏感度及准确度明显高于常规MRI(P<0.05).结论 MR检查特别是MR间接关节造影能够准确显示肩关节常见病变及相关组织的病理发展过程,为临床诊断及治疗提供影像学依据.     

Superior labrum anterior-posterior lesions: diagnosis with MR arthrography of the shoulder

PURPOSE: To determine the accuracy of magnetic resonance (MR) arthrography in the diagnosis of superior labrum anterior-posterior (SLAP) lesions of the shoulder. MATERIALS AND METHODS: From January 1995 to June 1998, MR arthrography of the shoulder was performed in 159 patients with a history of chronic shoulder pain or instability. Fifty-two patients underwent arthroscopy or open surgery 12 days to 5 months after MR arthrography. Diagnostic criteria for SLAP lesion included marked fraying of the articular aspect of the labrum, biceps anchor avulsion, inferiorly displaced bucket handle fragment, and extension of the tear into the biceps tendon fibers. Surgical findings were correlated with those from MR arthrography. RESULTS: SLAP injuries were diagnosed at surgery in 19 of the 52 patients (37%). Six of the 19 lesions (32%) were classified as type I, nine (47%) as type II, one (5%) as type III, and three (16%) as type IV. MR arthrography had a sensitivity of 89% (17 of 19 patients), a specificity of 91% (30 of 33 patients), and an accuracy of 90% (47 of 52 patients). The MR arthrographic classification showed correlation with the arthroscopic or surgical classification in 13 of 17 patients (76%) in whom SLAP lesions were diagnosed at MR arthrography. CONCLUSION: MR arthrography is a useful and accurate technique in the diagnosis of SLAP lesions of the shoulder. MR arthrography provides pertinent preoperative information with regard to the exact location of tears and grade of involvement of the biceps tendon.     

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.     

The diagnostic value of magnetic resonance arthrography of the shoulder in detection and grading of SLAP lesions: comparison with arthroscopic findings

Purpose

The purpose of the study is to determine the usefulness of magnetic resonance arthrography (MRA) in diagnosis and grading of superior labrum anterior to posterior (SLAP) lesions of the Glenoid Labrum Compared with surgery

Material and methods

This was a prospective study including fifty nine clinically diagnosed SLAP patients. The study was done during the period from January 2008 to June 2010. All patients were submitted to history taking, clinical examination and conventional MRI examination of the shoulder, MRA was done in patients with negative conventional MRI, all of these patients underwent arthroscopy for diagnosis wither open or arthroscopy for diagnosis and treatment and results were compared with MRA findings.

Main outcome measures

Sensitivity, specificity, positive and negative predictive values, and overall accuracy of MR arthrography in detection and grading of SLAP lesions of the gelnoid labrum.

Results

Out of fifty nine patients, 25 patients had positive MR findings in conventional MRI, and 34 patients had negative MR findings, who underwent MR arthrography; 10 out of them had normal arthrogram (only 6 of them underwent arthroscopy), 22 had SLAP (superior labrum anterior to posterior) lesions, one had Bankart's lesion and one had internal impingement syndrome. These results were compared with arthroscopy results.The overall sensitivity of MRA in detection of SLAP lesions was 90% while the specificity was 50%, negative predictive value (NPV) was 66.6% and positive predicative value (PPV) was 81.8%. MRA and arthroscopy results were concurrent in 79.3% patients.

Conclusion

MR arthrography is a sensitive minimally invasive technique for detection and grading of SLAP lesions, it can help in avoiding patients unnecessary diagnostic arthroscopy.     

Diagnosis of SLAP lesions with Grashey-view arthrography

OBJECTIVE: To examine the accuracy of Grashey views obtained during shoulder arthrography in the diagnosis of clinically relevant superior labrum anterior-posterior (SLAP) lesions. DESIGN AND PATIENTS: Grashey views obtained during diagnostic arthrography (conventional and MR) were used to examine the superior labrum. Twenty-eight of 118 shoulder arthrograms obtained during a 27-month period fulfilled study criteria and were correlated for accuracy using arthroscopically confirmed grade 2-4 SLAP lesions as the standard of reference. Arthrograms were graded using the consensus method. Prevalence, sensitivity, specificity, and accuracy were 21%, 50%, 86%, and 79%. The appearance of the superior labrum on the Grashey view was compared subjectively with MR arthrography. Sources of errors were analyzed. CONCLUSION: Grashey views obtained during shoulder arthrography can diagnose clinically relevant SLAP lesions with moderately high specificity, moderate accuracy, and limited sensitivity. Findings on the Grashey view closely resemble those seen on coronal oblique MR arthrography. Grashey views should be considered in patients undergoing shoulder arthrography.     

Comparative study of direct MR arthrography and CT arthrography with arthroscopic correlation in preoperative evaluation of anterior shoulder instability

Purpose

To compare direct MR arthrography and CT arthrography for the preoperative planning of shoulder anterior instability.

Patients and methods

47 patients were included in this study. 43 patients with clinical history of anterior GHI or recurrent shoulder pain had no clinical findings of rotator cuff abnormality. They experienced multiple anterior dislocations of the shoulder. No patient showed evidence of multidirectional instability or generalized ligamentous laxity. The remaining 4 patients complained of anterior shoulder instability after anchor repair. All the patients underwent direct CT and MR arthrography. The results of CTA and MRA were compared with results obtained from arthroscopy in each patient to detect the sensitivity and specificity of each modality.

Results

The sensitivity and specificity of CTA for bankart lesion are 89.4% and 96.4% respectively and of MRA 94.7% and 96.4%, for Perthes lesion the sensitivity and specificity of CTA are 33.3% and 100% respectively and of MRA 66.6% and 100%, for ALPSA the sensitivity and specificity of CTA are 85.7% and 97.5% respectively and of MRA 100% and 97.5%, for GLAD the sensitivity and specificity of CTA are 80% and 97.6% respectively and of MRA 60% and 97.6%, for SLAP lesion the sensitivity and specificity of CTA are 100% and 100% respectively and of MRA 100% and 100%, for absent or degenerated labrum the sensitivity and specificity of CTA are 100% and 100% respectively and of MRA 66.6% and 97.7%, for post operative recurrent Bankart lesion the sensitivity and specificity of CTA are 100% and 100% respectively and of MRA 50% and 100%, for bony glenoid fracture the sensitivity and specificity of CTA are 100% and 100% respectively and of MRA 66.6% and 97.5%.

Conclusion

CTA and MRA were equivalent in demonstrating labro-ligamentous and cartilaginous lesions associated with shoulder instability. CTA was superior in detecting post operative instability and glenoid rim osseous lesions that are known to be a decisional element in the surgical strategy. Hence, CTA may be considered a method of choice in the preoperative evaluation of shoulder anterior 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。     

水激发三维VIBE肩关节MR造影对Bankart病变的评价

目的评价肩关节MR造影水激发三维容积内插梯度回波(volumetric interpolated breath-hold examination,VIBE)序列对Bankart病变的诊断价值。资料与方法由2名影像诊断医师独立回顾99例肩关节MR造影常规序列和三维VIBE重建图像,判定有无Bankart病变以及骨性Bankart病变,计算其敏感性和特异性。采用McNemar检验评价常规序列与三维VIBE的诊断价值差异是否存在统计学意义。结果 99例患者中,关节镜证实前下方盂唇完整41例,Bankart病变58例,其中26例为骨性Bankart病变。三维VIBE对Bankart病变的敏感性、特异性分别为91.38%～93.10%和95.12%～97.56%;对骨性Bankart病变分别为96.15%和95.89%～97.26%。常规序列对Bankart病变的敏感性、特异性分别为91.38%～96.55%和97.56%;对骨性Bankart病变分别为42.31%～50%和97.26%～100%。三维VIBE和常规序列对于Bankart病变的诊断性能差异无统计学意义,但前者判断骨性Ban-kart病变的敏感性显著优于后者。结论在肩关节MR造影中,水激发三维VIBE序列可全面评价Bankart病变。     

肩袖撕裂的肩关节MR造影评价

目的 评价肩关节MR造影对肩袖撕裂的诊断价值。方法 分析32例病人的肩关节MR造影图像,评价内容包括肩袖肌腱、盂唇、肱二头肌长头腱,结果与肩关节镜及肩部开放手术比较。结果 以肩关节镜和手术结果为标准,32例病人包括14例全层撕裂,6例下表面部分撕裂,12例无撕裂。肩关节MR造影判定有无肩袖撕裂的敏感性、特异性和准确性都为100％;诊断全层撕裂的敏感性、特异性和准确性分别为100％、94％和97％。同时,肩关节MR造影还正确诊断了所有的多肌腱撕裂、合并的盂唇异常及肱二头肌长头腱异常。结论 肩关节MR造影可以准确、全面地评价肩袖撕裂。     

3D-SPACE序列在肩关节MR造影中评估上盂唇前后撕裂

目的：评价肩关节 MR造影三维各向同性脂肪抑制快速自旋回波（SPACE）序列对上盂唇前后撕裂（SLAP损伤）的诊断价值。方法：影像诊断医师回顾性分析经关节镜证实的肩关节 MR 造影图像,判定有无SLAP 损伤及分型,对比常规二维序列和SPACE序列对SLAP损伤的敏感度、特异度及准确率,比较常规二维序列与SPACE 序列的诊断价值。结果：肩关节镜证实SLAP损伤12例,肩关节 MR造影SPACE序列与常规二维序列对SLAP 损伤的敏感度分别为83．33％（10/12）及91．67％（11/12）,特异度分别为81．25％（13/16）及87．50％（14/16）,准确度分别为82．14％（23/28）及89．29％（25/28）。SPACE序列与常规二维序列对 SLAP 损伤的诊断效能无明显统计学差异（P＞0．05）。结论：肩关节MR造影中SPACE序列是评价SLAP损伤准确、可靠的影像学方法。     

Is a single direct MR arthrography series in ABER position as accurate in detecting anteroinferior labroligamentous lesions as conventional MR arthography?

Purpose  The purpose of this study is to retrospectively compare accuracy of single magnetic resonance (MR) arthrography series in Abduction External Rotation (ABER) with conventional MR arthrography for detection and characterisation of anteroinferior labroligamentous lesions, with arthroscopy as reference standard. Inter-observer variability of both protocols was determined. Methods and materials  Institutional review board approval was obtained; informed consent was waived. MR arthrograms, including oblique axial fat suppressed T1-weighted images in ABER position and conventional imaging directions of 250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and independently evaluated by three reviewers. Reviewers were blinded to clinical information and arthroscopic results. Labroligamentous lesions were registered in both ABER and MRa. The lesions were sub-classified (Bankart, Perthes, anterior labrum periosteal sleeve avulsion (ALPSA) or lesions not otherwise specified). Inter-observer agreement was assessed by Kappa statistics for all 250 patients. Ninety-two of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus conventional MR arthrography were calculated and compared using paired McNemar test. Results  Kappa values of the ABER and conventional MR arthrography ranged from 0.44 to 0.56 and 0.44 to 0.62, respectively. According to arthroscopy, 45 of 92 patients had an intact anteroinferior labrum, and in 44 patients, a labroligamentous lesion (eight Bankart, seven Perthes, 29 ALPSA and three lesions not otherwise specified) was diagnosed. There were no statistically significant differences between ABER and conventional MR arthrography regarding sensitivity (85–89%, 89–96%), specificity (82–91%, 84–89%) and overall accuracy (50–62%, 53–63%). Conclusion  The results of a single MR arthrography series in ABER position are comparable with those of conventional MR arthrography for detecting anteroinferior labroligamentous lesions.     

Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation

OBJECTIVE: Conventional radiography, arthrography, CT arthrography, and MR arthrography--including use of the abduction and external rotation position--were compared, with arthroscopic correlation, to determine the spectrum of abnormalities encountered and the relative benefits of each imaging method in the evaluation of shoulder lesions occurring in 17 throwing athletes. SUBJECTS AND METHODS: Each of 36 athletes with shoulder pain aggravated by abduction and external rotation was examined in a single visit during which conventional radiography, arthrography, CT arthrography, and MR arthrography were performed. In 17 of these athletes, imaging findings were compared with those at arthroscopy. All images were independently evaluated by two groups of musculoskeletal radiologists. RESULTS: Structures found to be affected were, in decreasing order of frequency, the following: the posterosuperior labrum, supraspinatus tendon, infraspinatus tendon, humeral head, glenoid cavity and rim, acromioclavicular joint, anteroinferior capsulolabral complex, biceps tendon, and subscapularis tendon. MR arthrography without and with abduction and external rotation yielded the highest sensitivity and specificity for all lesions with the exceptions of bone sclerosis and enthesophytes (which were best seen with CT arthrography). MR arthrography with abduction and external rotation was most accurate for diagnosis of rotator cuff and anteroinferior capsulolabral complex tears. CONCLUSION: On the basis of these preliminary results, we believe that MR arthrography with abduction and external rotation should be part of the imaging evaluation of shoulder pain in throwing athletes, owing to the high sensitivity of this imaging technique.     

上方盂唇前后向撕裂的肩关节MR造影评价

目的 评价肩关节MR造影对上方盂唇前后向撕裂(SLAP损伤)的诊断价值.方法 由2名影像诊断医师独立回顾分析137例经肩关节镜证实的肩关节造影MR图像,判定有无SLAP损伤,并进行分型.SLAP损伤分4型:Ⅰ型为上盂唇毛糙,Ⅱ型为肱二头肌腱盂唇复合体从关节孟撕裂,Ⅲ型为上盂唇桶柄状撕裂,Ⅳ型为上盂唇桶柄状撕裂并同时累及肱二头肌长头腱.计算肩关节MR造影对SLAP损伤的敏感度、特异度和准确度,以及与肩关节镜分型的符合率.采用Kappa统计计算2名影像诊断医师评价的一致性.结果 137例患者中,肩关节镜证实SLAP损伤59例,包括SLAP损伤Ⅰ型6例(10.2%)、Ⅱ型50例(84.7%)、Ⅲ型3例(5.1%).肩关节MR造影的敏感度、特异度和准确度医师甲分别为86.4%(51/59)、78.2%(61/78)和81.8%(112/137),医师乙分别为88.1%(52/59)、84.6%(66/78)和86.1%(118/137).2名影像诊断医师的评价一致性极好(K=0.796).肩关节MR造影与肩关节镜的分型符合率医师甲为83.1%(49/59),医师乙为79.7%(47/59).结论 肩关节MR造影是评价SLAP损伤比较可靠的影像方法.     

Comparison of MR arthrography with arthroscopy of the hip for the assessment of intra-articular loose bodies

Objective To assess the specificity and sensitivity of MR arthrography of the hip in comparison with arthroscopy for the evaluation of intra-articular loose bodies. Design Over a 3-year period, 81 consecutive patients underwent a total of 82 hip arthroscopies by a single orthopedic surgeon for intractable hip pain. Of the 82 arthroscopies, 70 had pre-operative MR arthrograms. Of these, 57 were available for retrospective review, after which they were compared with the operative notes of the subsequent arthroscopies. Results Of 82 arthroscopies 16 (20%) demonstrated intra-articular loose bodies, while, in the study group, nine of 57 had loose bodies (16%). There was a total of seven discordant cases (five false negatives and two false positives). The sensitivity of MR arthrography for detection of intra-articular loose bodies was 44%, while the specificity was 96%. Conclusion While the specificity of MR arthrography for the detection of intra-articular loose bodies was high (96%), the sensitivity was not nearly as good (44%). Presented at the Special Scientific Section of the ISS in Vancouver, Canada, September 2006.     

Sensitivity of MR arthrography in the evaluation of acetabular labral tears

OBJECTIVE: MRI has historically provided suboptimal visualization of tears of the acetabular labrum. Degenerative fraying and underlying cartilage abnormalities can often mimic tears of the labrum on conventional MRI. Administration of intraarticular gadolinium enhances the MRI appearance of the labrum to improve detection of labral abnormalities. This study examined the improved diagnostic sensitivity of MR arthrography compared with conventional MRI and the importance of confining the study to a small field of view. MATERIALS AND METHODS: Fifty-one hips were imaged in 48 patients. Fourteen hips underwent conventional MRI with a large field of view (30-38 cm). Seven hips underwent conventional MRI with a small field of view (14-20 cm). Thirty hips underwent MR arthrography with a small field of view (14-20 cm). Labral tears were diagnosed when contrast material was identified within the labrum or between the labrum and the acetabulum, when a displaced fragment was noted, or when a paralabral cyst was identified. All study results were compared with findings at the time of hip arthroscopy. RESULTS: Conventional MRI with a large field of view was 8% sensitive in detecting labral tears compared with findings at the time of arthroscopy. Diagnostic sensitivity was improved to 25% with a small field of view. MR arthrography with a small field of view was 92% sensitive in detecting labral tears. CONCLUSION: A combination of MR arthrography and a small field of view is more sensitive in detecting labral abnormalities than is conventional MRI with either a large or a small field of view.     

Indirect magnetic resonance arthrography of the shoulder; a reliable diagnostic tool for investigation of suspected labral pathology

Purpose

Indirect magnetic resonance arthrography (I-MRA) confers significant logistical advantages over direct MRA and does not require articular injection. In this study, we determined the diagnostic performance of I-MRA in relation to conventional MRI and arthroscopy or surgery in detecting tears of the glenoid labrum, including Bankart lesions and superior labral antero-posterior (SLAP) tears in a standard clinical setting.

Patients and methods

Ninety-one symptomatic patients underwent conventional MRI and I-MRA of the affected shoulder, followed by either arthroscopy or open surgery. The scans were interpreted independently by two experienced radiology consultants with a special interest in musculoskeletal radiology. Using the surgical findings as the standard of reference, sensitivity, specificity, and diagnostic accuracy of conventional non-contrast MRI and I-MRA in the detection of labral tears were calculated.

Results

The sensitivity of I-MRA was 95 and 97 %, respectively, for two radiologists as opposed to 79 and 83 % for conventional MRI. For both radiologists, the specificity of I-MRA, as well as MRI, was 91 % for detection of labral tears of all types. Accuracy of diagnosis was 93 and 95 %, respectively, for two radiologists with indirect MRA, compared to 84 and 86 % with non-contrast MRI.

Conclusions

This retrospective study shows that I-MRA is a highly accurate and sensitive method for the detection of labral tears. The data obtained supports the use of I-MRA as standard practice in patients with shoulder instability due to suspected labral pathology where further investigative imaging is indicated.     

The value of ultrasonography in the preoperative diagnostic evaluation of patients with recurrent anterior shoulder dislocation: a prospective study of 44 patients

The purpose of this study was to investigate the value of ultrasonography in the pre-operative assessment of patients with recurrent post-traumatic, anterior shoulder instability. Forty-four consecutive patients, 44 men and 12 women, with unilateral, post-traumatic, recurrent instability of the shoulder were included in the study. One experienced radiologist examined all patients, using a 5.0 or 7.5 MHz linear-array transducer, with the arm in different positions, one of which was used to provoke apprehension of the shoulder. Special attention was paid to the evaluation of the joint capsule, the anterior labrum, especially in terms of the presence of a Bankart lesion. All patients were subsequently treated surgically. After a diagnostic arthroscopy either an open or arthroscopic stabilisation of the shoulder was performed. Ultrasonography disclosed an unstable anterior labrum (equivalent to a Bankart lesion) in 36 shoulders; the lesion was verified in all 36 shoulders during arthroscopy. In three shoulders, arthroscopy disclosed an injured labrum, which had healed in an anterio-medial position on the scapular neck. In these three shoulders, ultrasonography failed to show any lesion. In five shoulders no Bankart lesion was found at arthroscopy. All these patients had increased shoulder laxity, and ultrasonography did not show any Bankart lesion. Furthermore a judgement of the joint capsule was not possible either. A bony Bankart lesion was found in four shoulders, using both arthroscopy and ultrasonography. The sensitivity of the ultrasonographic evaluation was 92%, and the specificity 100%. The positive predictive value was 100%, and the negative predictive value 63%. Ultrasonography showed a high correlation with the arthroscopic findings, with a high sensitivity and specificity. Therefore, we conclude that US can give important pre-operative information in patients with recurrent, unilateral, post-traumatic, anterior shoulder instability.     

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

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.