Diagnostic value of MR Arthrogram in SLAP lesions of the shoulder

Biceps Tenodesis Demonstrates Lower Reoperation Rates Compared to SLAP Repair for Treatment of SLAP Tears in a Large Cross-Sectional Population

PURPOSE

To use a contemporary cross-sectional data set to evaluate trends in surgical treatment for superior labrum anterior and posterior (SLAP) tears and compare surgical outcomes with respect to 2-year revision surgery rates following index SLAP repair versus biceps tenodesis (BT).

METHODS

Patients diagnosed with a SLAP tear between 2010 and 2017 were queried using the Mariner PearlDiver database and stratified by demographic variables and surgical treatment with arthroscopic SLAP repair or arthroscopic/open BT. From 2015 to 2017, Current Procedural Terminology (CPT) and International Classification of Diseases 10th revision (ICD-10) codes were used to track ipsilateral subsequent reoperation within 2-years of index surgery.

RESULTS

Between 2010 to 2017, 16.6% of 377,463 patients diagnosed with a SLAP tear underwent surgery (62.3% SLAP repair vs 37.7% BT). 52.4% of BT procedures were arthroscopic (47.6% open). The frequency of SLAP repairs decreased from 74.0% to 46.2% (61%), while the frequency of BTs increased from 26.0% to 53.8% (202%) during the study period. Patients under age 50 were more likely to undergo SLAP repair, and those undergoing BT were more likely to be over 50 with higher CCI and comorbidity risk. 6.3% of 16,186 patients identified with ICD-10 coding required reoperation within 2-years postoperatively. SLAP repair demonstrated a higher revision rate (6.8%; 95% CI, 6.3-7.4%) than BT (5.7%; 95% CI, 5.2-6.2%; P =.0002), (open 5.8% vs arthroscopic BT 5.5%). Arthroscopic debridement, including biceps tenotomy, revision SLAP repair, and revision BT were the most common subsequent procedures. Patients aged 40 to 49 had the highest rate of revision surgery (7.8%).

CONCLUSIONS

The treatment trend for SLAP tears is changing, with SLAP repair becoming significantly less utilized and BT now becoming the preferred option, especially in patients over 50. Arthroscopic and open BT demonstrated slightly lower risk for reoperation than SLAP repair.

LEVEL OF EVIDENCE

IV, cross-sectional study.

Imaging of Patients Suspected of SLAP Tear: A Cost-Effectiveness Study

Background: Superior labral anterior-to-posterior (SLAP) tears are a common shoulder pathology. While MRI is the imaging gold standard for diagnosis of this pathology, the cost-effectiveness of the common MRI strategies is unclear. Objective: The primary objective of our study was to determine the cost-effectiveness of the common MRI-based strategies used for the diagnosis of SLAP tears. Methods: We created decision analytic models from the U.S. health care system perspective over a two-year time horizon for a hypothetical patient population of 25-year-olds with a previous diagnosis of SLAP tear. We used the decision models to compare the differences in incremental cost-effectiveness of the common MRI strategies and resulting treatment applied for this patient type, which included combinations of 1.5T and 3T imaging and unenhanced MRI and MR arthrogram protocols. Input data on cost, probability, and utility estimates were obtained through a comprehensive literature search. The primary effectiveness outcome was quality-adjusted life years (QALY). Costs were estimated in 2017 U.S. dollars. Results: When all imaging strategies were considered, the unenhanced 3T MRI based imaging strategy was the preferred and dominant option over 3T MR arthrography (MRA) and 1.5T imaging (MRI/MRA). When the model was run without 3T imaging as an option, 1.5T MRA was the favored option. Probabilistic sensitivity analyses confirmed the same preferred imaging strategy results. Conclusion: An unenhanced 3T MRI based strategy is the most cost-effective imaging option for patients with suspected SLAP tear. When 3T imaging is not available, 1.5T MRA is more cost-effective than 1.5T imaging. The main driver of these results is the fact that 3T MRI and 1.5T MRA are the most specific tests in these respective scenarios which results in fewer false positives and prevents unnecessary surgeries leading to decreased costs. Clinical Impact: Our cost-effectiveness model findings complement prior diagnostic accuracy work, helping produce a more comprehensive approach to define imaging utility for the SLAP patient population for radiologists, clinicians, and patients who have access to various types of MRI options.

ACR Appropriateness Criteria® Shoulder Pain-Traumatic

Traumatic shoulder pain is pain directly attributed to a traumatic event, either acute or chronic. This pain may be the result of either fracture (the clavicle, scapula, or proximal humerus) or soft-tissue injury (most commonly of the rotator cuff, acromioclavicular ligaments, or labroligamentous complex). Imaging assessment of traumatic shoulder pain begins with conventional radiography and, depending on physical examination findings, will require MRI or MR arthrography for assessment of soft-tissue injuries and CT for delineation of fracture planes. Ultrasound excels in assessment of rotator cuff injuries but has limited usefulness for assessment of the deep soft-tissues. CT angiography and conventional arteriography are helpful for assessment of vascular injury, and bone scintigraphy can be used in assessment of complex regional pain syndrome after traumatic shoulder injury. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Current Concepts in the Evaluation and Management of Type II Superior Labral Lesions of the Shoulder

Background:

Superior labrum tears extending from anterior to posterior (SLAP lesion) are a cause of significant shoulder pain and disability. Management for these lesions is not standardized. There are no clear guidelines for surgical versus non-surgical treatment, and if surgery is pursued there are controversies regarding SLAP repair versus biceps tenotomy/tenodesis.

Objective:

This paper aims to briefly review the anatomy, classification, mechanisms of injury, and diagnosis of SLAP lesions. Additionally, we will describe our treatment protocol for Type II SLAP lesions based on three groups of patients: throwing athletes, non-throwing athletes, and all other Type II SLAP lesions.

Conclusion:

The management of SLAP lesions can be divided into 4 broad categories: (1) nonoperative management that includes scapular exercise, restoration of balanced musculature, and that would be expected to provide symptom relief in 2/3 of all patients; (2) patients with a clear traumatic episode and symptoms of instability that should undergo SLAP repair without (age < 40) or with (age > 40) biceps tenotomy or tenodesis; (3) patients with etiology of overuse without instability symptoms should be managed by biceps tenotomy or tenodesis; and (4) throwing athletes that should be in their own category and preferentially managed with rigorous physical therapy centered on hip, core, and scapular exercise in addition to restoration of shoulder motion and rotator cuff balance. Peel-back SLAP repair, Posterior Inferior Glenohumeral Ligament (PIGHL) release, and treatment of the partial infraspinatus tear with debridement, PRP, or (rarely) repair should be reserved for those who fail this rehabilitation program.

What are the anatomical predictive factors of degenerative superior labrum anterior to posterior lesion in rotator cuff tear?

The purpose of this study was to evaluate the influence of anatomical factors degenerative superior labrum anterior to posterior lesion in rotator cuff tear. The study included 421 middle-aged patients treated using arthroscopic surgery for rotator cuff tears. Patients were divided into two groups based on the superior labrum anterior-to-posterior (SLAP). Glenoid inclination, glenoid length, humeral head diameter, acromio-humeral distance (AHD) head-glenoid difference (HGD), head glenoid angle (HGA), size and retraction of rotator cuff tears were evaluated in both groups. In conclusion, a HGD exceeding 10 mm could be anatomically predictive of degenerative SLAP.

LEVEL OF EVIDENCE

Case series, Level IV.

A systematic review and meta-analysis of diagnostic test of MRA versus MRI for detection superior labrum anterior to posterior lesions type II-VII

OBJECTIVE

To determine the diagnostic performance of magnetic resonance arthrography (MRA) and magnetic resonance imaging (MRI) in superior labrum anterior to posterior lesions (type II-VII) of the shoulder.

MATERIAL AND METHODS

PubMed and Scopus search engines, an electronic search of articles was performed from inception to February 19, 2016. Diagnostic performance of index tests was compared by the summary area under receiver operator characteristic curve (AUROC).

RESULTS AND CONCLUSIONS

In all, 117 of 493 studies were eligible and 32 studies (2,013 shoulders) and 11 studies (1,498 shoulders) were evaluated with MRA and MRI. The summary sensitivity, specificity, likelihood ratio (positive and negative) and AUROC were 0.87 (95 % confidence interval, CI: 0.82, 0.91), 0.92 (95 %CI: 0.85, 0.95), 10.28 (95 %CI: 5.84, 18.08), 0.14 (95 %CI: 0.10, 0.20) and 0.94 (95 %CI: 0.92, 0.96) respectively for MRA, and 0.76 (95 %CI: 0.61, 0.86), 0.87 (95 %CI: 0.71, 0.95), 5.89 (95 %CI: 2.5, 13.86), 0.28 (95 %CI: 0.17, 0.47) and 0.94 (95 %CI: 0.92, 0.96) respectively for MRI. The diagnostic performance of MRA was superior to MRI by both direct and indirect comparisons for the detection of SLAP lesions.

Reliability of magnetic resonance imaging versus arthroscopy for the diagnosis and classification of superior glenoid labrum anterior to posterior lesions

PURPOSE

The physical examination of the shoulder is usually not reliable for the true diagnosis of superior glenoid labrum anterior to posterior (SLAP) lesions. Magnetic resonance imaging (MRI) has been routinely used for the diagnosis. This prospective study investigates the radiological diagnosis of the SLAP lesions and compares accuracy of arthroscopic and MRI classifications.

METHODS

One hundred thirty-two patients with positive physical examination signs using O'Brien, Yergason, resistance supination external rotation and Krank tests and MRI findings are included in the study. Shoulder MRIs were obtained for all patients within three months prior to the surgeries. SLAP lesion is detected in 90 and 102 patients according to MRI and arthroscopy, respectively. Arthroscopic and MRI classifications of the patients were performed according to modified Snyder classification.

RESULTS

Sensitivity and specificity of the MRI were found as 70.59 and 40%, respectively. No difference was detected between MRI and arthroscopy classifications in 52 (39%) patients. Although the diagnosis was compatible with arthroscopy in 34 (25%) patients, the classification was incompatible. In 46 (34%) of patients the diagnosis was incompatible with the MRI.

CONCLUSION

Although MRI is a good diagnostic tool for SLAP lesions, its use for the classification is limited. Level of evidence Level III, Diagnostic study.

Correlation between MRI and Arthroscopy in Diagnosis of Shoulder Pathology

INTRODUCTION

Shoulder pain can cause significant pain, discomfort and reduce the ability to perform activities of daily living, thus making it the third most common cause of musculoskeletal consultation. The current gold standard diagnostic investigation is arthroscopy. MRI is a proved sensitive and accurate non-invasive tool in investigating shoulder pathology, but false and misleading results are equally reported.

AIM

The aim of the study is to compare the efficacy of MRI in diagnosing shoulder pathologies in comparison to arthroscopy, considering arthroscopy as the gold standard.

MATERIALS AND METHODS

Thirty nine consecutive patients, between 18-80 years of age, presenting with chronic shoulder pain or instability of more than 6 weeks, or with clinical signs of impingement or tear were included in the study. MRI of the shoulder joint was done followed by shoulder arthroscopy. The data collected was analysed for the significant correlation between MRI of shoulder and arthroscopic findings by kappa statistics.

RESULTS

Out of 39 patients, Rotator cuff (RC) tear was the most common pathology. MRI showed excellent sensitivity in the diagnosis of rotator cuff tears (0.91) and osteochondral defects (OCD), very good sensitivity for Bankart's lesion (0.8) and had poor sensitivity to detect SLAP tear (0.15). MRI was specific for all shoulder pathologies. MRI detected RC tears with kappa score of 0.73, Bankart's tear and OCD's with kappa score of 0.83 and 1.0 respectively and SLAP lesion with kappa score of 0.14. The accuracy of MRI was highest in diagnosing OCD's (1.0), followed by RC tear (0.9), Bankart's tear (0.9) and accuracy was least in diagnosing SLAP lesion (0.7). False negative results were more than false positives.

CONCLUSION

The present study supports that MRI is effective in diagnosing rotator cuff tears, Bankart's tear and ostechondral defects but was not found to be helpful in diagnosing SLAP lesions. MRI and arthroscopy have complimentary roles in the diagnosis of shoulder pathology.

Are radiologists superior to orthopaedic surgeons in diagnosing instability-related shoulder lesions on magnetic resonance arthrography? A multicenter reproducibility and accuracy study

BACKGROUND

We compared the diagnostic reproducibility and accuracy of musculoskeletal radiologists with orthopaedic shoulder surgeons in 2 large medical centers in assessing magnetic resonance arthrograms (MRAs) of patients with traumatic anterior shoulder instability.

METHODS

Forty-five surgically confirmed MRAs were assessed by 4 radiologists, 4 orthopaedic surgeons, 2 radiologic teams, and 2 orthopaedic teams. During MRA assessment and surgery, the same 7-lesion scoring form was used. κ Coefficients, sensitivity, specificity, and differences in percentage of agreement or correct diagnosis (P < .05, McNemar test) were calculated per lesion and overall per the 7 lesion types.

RESULTS

The overall κ between the individual radiologists (κ = 0.51, κ = 0.46) and orthopaedic surgeons (κ = 0.46, κ = 0.41) was moderate. Although the overall percentage of agreement between the radiologists was slightly higher than that between the orthopaedic surgeons in both centers (80.0% vs 77.5% and 75.2% vs 73.7%), there was no significant difference. In each medical center, however, the most experienced orthopaedic surgeon was exceedingly more accurate than both radiologists per the 7 lesion types (81.9% vs 72.4%/74.6% and 76.5% vs 67.3%/73.7%). In 3 of 4 cases, this difference was significant. Overall accuracy improvement through consensus assessment was merely established for the weakest member of each team.

CONCLUSION

Experienced orthopaedic surgeons are more accurate than radiologists in assessing traumatic anterior shoulder instability-related lesions on MRA. In case of diagnosis disagreement, these orthopaedic surgeons should base their treatment decision on their own MRA interpretation.

Accuracy of magnetic resonance imaging to diagnose superior labrum anterior-posterior tears

PURPOSE

The purpose of this study was to evaluate the accuracy of magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) in diagnosing superior labral anterior-posterior (SLAP) lesions. We hypothesized that the accuracy of MRI and MRA was lower than previously reported.

METHODS

Between 2006 and 2008, 444 patients who had both shoulder arthroscopy and an MRI (non-contrast or MR arthrography) for shoulder pain at our institution prior to surgery were identified and included in the study. The radiologic diagnosis and surgical evaluation were compared to determine the accuracy of diagnosing a SLAP lesion by MRI. Using arthroscopy as the standard, sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated for all MRIs, as well as separately for the non-intra-articular contrast MRI group and the MR arthrography group.

RESULTS

Of the 444 patients having an MRI and arthroscopy for shoulder pain, 121 had a SLAP diagnosis by MRI and 44 had a SLAP diagnosis by arthroscopy. Overall, MRI had an accuracy of 76 %, a PPV of 24 %, and a NPV of 95 %. Sensitivity was 66 %, and specificity was 77 %. MR arthrography had an accuracy of 69 %, sensitivity of 80 %, and a PPV of 29 %. Non-contrast MRI had an accuracy of 85 %, sensitivity of 36 %, and a PPV of 13 %.

CONCLUSIONS

In our retrospective study of 444 patients, sensitivity, specificity, and accuracy were all lower than previously reported in the literature for diagnosing SLAP lesions. Our data indicated that while MRI could exclude a SLAP lesion (NPV = 95 %), MRI alone was not an accurate clinical tool. MR arthrography had a large number of false-positive readings in this study. We concluded that even with intra-articular contrast, MRI had limitations in the ability to diagnose surgically proven SLAP lesions.

Does the experience level of the radiologist, assessment in consensus, or the addition of the abduction and external rotation view improve the diagnostic reproducibility and accuracy of MRA of the shoulder?

AIM

To prospectively evaluate the influence of observer experience, consensus assessment, and abduction and external rotation (ABER) view on the diagnostic performance of magnetic resonance arthrography (MRA) in patients with traumatic anterior-shoulder instability (TASI).

MATERIALS AND METHODS

Fifty-eight MRA examinations (of which 51 had additional ABER views) were assessed by six radiologists (R1-R6) and three teams (T1-T3) with different experience levels, using a seven-lesion standardized scoring form. Forty-five out of 58 MRA examination findings were surgically confirmed. Kappa coefficients, sensitivity, specificity, and differences in percent agreement or correct diagnosis (p-value, McNemar's test) were calculated per lesion and overall per seven lesion types to assess diagnostic reproducibility and accuracy.

RESULTS

Overall kappa ranged from poor (k = 0.17) to moderate (k = 0.53), sensitivity from 30.6-63.5%, and specificity from 73.6-89.9%. Overall, the most experienced radiologists (R1-R2) and teams (T2-T3) agreed significantly more than the lesser experienced radiologists (R3-R4: p = 0.014, R5-R6; p = 0.018) and teams (T2-T3: p = 0.007). The most experienced radiologist (R1, R2, R3) and teams (T1, T2) were also consistently more accurate than the lesser experienced radiologists (R4, R5, R6) and team (T3). Significant differences were found between R1-R4 (p = 0.012), R3-R4 (p = 0.03), and T2-T3 (p = 0.014). The overall performance of consensus assessment was systematically higher than individual assessment. Significant differences were established between T1-T2 and radiologists R3-R4 (p<0.001, p = 0.001) and between T2 and R3 (p<0.001/p = 0.001) or R4 (p = 0.050). No overall significant differences were found between the radiologists' assessments with and without ABER.

CONCLUSION

The addition of ABER does not significantly improve overall diagnostic performance. The radiologist's experience level and consensus assessment do contribute to higher reproducibility and accuracy.

Analysis of Low-Field MRI Scanners for Evaluation of Shoulder Pathology Based on Arthroscopy

BACKGROUND

Many studies have compared the diagnostic capabilities of low-field magnetic resonance imaging (MRI) scanners to high-field MRI scanners; however, few have evaluated the low-field MRI diagnoses compared with intraoperative findings.

PURPOSE

To determine the accuracy and sensitivity of low-field MRI scanners in diagnosing lesions of the rotator cuff and glenoid labrum.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Over a 2-year period, MRI examinations without intra-articular contrast were performed on 79 patients for shoulder pathologies using an in-office 0.2-T extremity scanner. The MRI examinations were read by board-certified, musculoskeletal fellowship-trained radiologists. All patients underwent shoulder arthroscopy performed by a single sports fellowship-trained orthopaedic surgeon within a mean time of 56 days (range, 8-188 days) after the MRI examination. The mean patient age was 54 years (range, 18-81 years). Operative notes from the shoulder arthroscopies were then retrospectively reviewed by a single blinded observer, and the intraoperative findings were compared with the MRI reports.

RESULTS

For partial-thickness rotator cuff tears, the sensitivity, specificity, positive predictive value, and negative predictive value were 85%, 89%, 79%, and 92%, respectively. For full-thickness rotator cuff tears, the respective values were 97%, 100%, 100%, and 98%. For anterior labral lesions, the values were 86%, 99%, 86%, and 99%, and for superior labral anterior-posterior (SLAP) lesions, the values were 20%, 100%, 100%, and 79%, respectively.

CONCLUSION

Low-field MRI is an accurate tool for evaluation of partial- and full-thickness rotator cuff tears; however, it is not effective in diagnosing SLAP lesions. More information is needed to properly assess its ability to diagnose anterior and posterior labral lesions.

Diagnostic performance of magnetic resonance arthrography of the shoulder in children

BACKGROUND

No reported data demonstrate the usefulness of magnetic resonance arthrography of the shoulder in children.

OBJECTIVE

To evaluate the sensitivity, specificity and accuracy of MR arthrography in the assessment of superior labral anteroposterior (SLAP) tears of the shoulder, Bankart-type injuries and Hill-Sachs lesions in children as compared to arthroscopy.

MATERIALS AND METHODS

We retrospectively interpreted 66 MR arthrograms of the shoulder and compared them with surgical findings. Assessment included evaluation of the osseous structures, labral-ligamentous complex and determination of skeletal maturity. We calculated sensitivity, specificity and accuracy and compared sensitivity and specificity between skeletally mature and immature children.

RESULTS

MR arthrography demonstrated a sensitivity, specificity and accuracy of 88%, 98% and 94%, respectively, for depiction of SLAP tears; 94%, 92% and 94% for detection of Bankart-type injuries; and 100%, 94% and 97% for diagnosing Hill-Sachs lesions. There was no statistical difference between the skeletally immature and skeletally mature groups.

CONCLUSION

There is no significant difference in the diagnostic accuracy of MR arthrography in skeletally immature versus skeletally mature children. MR shoulder arthrography is an effective method for the detection of labral and bone pathology.

Accuracy of abduction-external rotation MRA versus standard MRA in the diagnosis of intra-articular shoulder pathology

The goal of this study was to compare the accuracy of abduction-external rotation magnetic resonance arthrography (ABERMRA) with standard MRA in the diagnosis of intra-articular shoulder pathology.One hundred three consecutive patients undergoing preoperative direct MRA and subsequent arthroscopic examination were included in the study. Seventy-eight patients underwent standard MRA and 25 underwent ABERMRA. Specialist-trained musculoskeletal radiologists reported all scans, and attending shoulder surgeons performed all arthroscopies. Arthroscopic assessment revealed 11 partial-thickness rotator cuff tears, 3 full-thickness tears, 64 labral lesions (48 soft tissue and 16 significant bony), and 17 superior labrum anterior-posterior (SLAP) tears. The sensitivity/specificity for standard MRA was 0.56/0.99 for partial-thickness rotator cuff tears, 1.00/1.00 for full-thickness rotator cuff tears, 0.75/0.91 for soft tissue labral tears, 0.58/1.00 for significant bony glenoid lesions, and 0.50/0.91 for SLAP tears. Abduction-external rotation magnetic resonance arthrography increased the sensitivity/specificity to 1.00/0.85 for soft tissue labral tears, 0.75/1.00 for significant bony glenoid lesions, and 1.00/1.00 for SLAP tears, although it missed 2 of 2 partial-thickness rotator cuff tears.This study suggests that standard MRA is a valuable investigation tool for instability, SLAP tears, and rotator cuff tears, although limitations exist. Additional ABERMRA sequences appear to improve the diagnostic accuracy of soft tissue anterior and posterior labral tears, SLAP tears, and significant bony glenoid lesions and should be routinely requested by shoulder surgeons when ordering MRAs to obtain the maximum benefit from this invasive investigation.

Validity of noncontrast magnetic resonance imaging in diagnosing superior labrum anterior-posterior tears

BACKGROUND

The biceps labral complex has received much interest in recent years as a source of shoulder pain. Magnetic resonance imaging (MRI) is the imaging modality of choice for those patients with a suspected superior labrum anterior-posterior (SLAP) tear. The goal of this study was to look at the accuracy of MRI without arthrography to correctly identify SLAP tears.

METHODS

The study had a prospective, case-based, case-control design. Participants were consecutive patients seen at an orthopaedic outpatient clinic who received an MRI scan as part of their diagnostic cycle. All patients were aged at least 18 years, with various shoulder dysfunctions (impingement, rotator cuff tear, and so on) that were evaluated during a routine clinical evaluation. Arthroscopic surgery was performed as the reference standard for a SLAP lesion.

RESULTS

Seventy-seven patients were evaluated during arthroscopic surgery. The pretest probability of a SLAP lesion-only diagnosis was 18.2%, and for a SLAP lesion with or without a concomitant diagnosis, the pretest probability was 66.2%. In both cases, use of MRI led to post-test probability values that were worse when a positive finding was identified on the MRI scan.

DISCUSSION

The results of this study suggest that SLAP tears are often incorrectly diagnosed based on MRI evaluation, with MRI providing a high level of sensitivity and low level of specificity. On the basis of the results of this study, conventional MRI is not a suitable test to accurately evaluate the biceps labral complex for the presence of a SLAP tear.

A meta-analysis of the diagnostic test accuracy of MRA and MRI for the detection of glenoid labral injury

PURPOSE

Magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) have gained increasing favour in the assessment of patients with suspected glenoid labral injuries. The purpose of this study was to determine the diagnostic accuracy of MRI or MRA in the detection of gleniod labral lesions.

MATERIALS AND METHODS

A systematic review was undertaken of the electronic databases Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, AMED and CINAHL, in addition to a search of unpublished literature databases. All studies which compared the ability of MRI or MRA (index test) to assess gleniod labral tears or lesions, when verified with a surgical procedure (arthroscopy or open surgery-reference test) were included. Data extraction and methodological appraisal using the QUADAS tool were both conducted by two reviewers independently. Data were analysed through a summary receiver operator characteristic curve and pooled sensitivity and specificity analysis were calculated with 95% confidence intervals.

RESULTS

Sixty studies including 4,667 shoulders from 4,574 patients were reviewed. There appeared slightly greater diagnostic test accuracy for MRA over MRI for the detection of overall gleniod labral lesions (MRA-sensitivity 88%, specificity 93% vs. MRI sensitivity 76% vs. specificity 87%). Methodologically, studies recruited and identified their samples appropriately and clearly defined the radiological procedures. In general, it was not clearly defined why patients were lost during the study, and studies were poor at recording whether the same clinical data were available to the radiologist interpreting the MRI or MRA as would be available in clinical practice. Most studies did not state whether the surgeon interpreting the arthroscopic procedure was blinded to the results of the MR or MRA imaging.

CONCLUSIONS

Based on the available literature, overall MRA appeared marginally superior to MRI for the detection of glenohumeral labral lesions.

LEVEL OF EVIDENCE

Level 2a.

Is MRA an unnecessary expense in the management of a clinically unstable shoulder? A comparison of MRA and arthroscopic findings in 90 patients

BACKGROUND AND PURPOSE

In detection of glenoid labrum pathology, MR arthrography (MRA) has shown sensitivities of 88-100% and specificities of 89-93%. However, our practice suggested that there may be a higher frequency of falsely negative reports. We assessed the accuracy of this costly modality in practice.

PATIENTS AND METHODS

We retrospectively reviewed MRA reports of 90 consecutive patients with clinical shoulder instability who had undergone shoulder arthroscopy. All had a history of traumatic anterior shoulder dislocation and had positive anterior apprehension tests. All underwent arthroscopy and stabilization during the same procedure. We compared the findings, using arthroscopic findings as the gold standard in the identification of glenoid labrum pathology.

RESULTS

83 of the 90 patients had glenoid labrum tears at arthroscopy. Only 54 were correctly identified at MRA. All normal glenoid labra were identified at MRA. This gave a sensitivity of 65% and a specificity of 100% in identification of all types of glenoid labrum tear. 74 patients had anterior glenoid labral tears that were detected at an even lower rate of sensitivity (58%).

INTERPRETATION

The sensitivity of MRA in this series was substantially lower than previously published, suggesting that MRA may not be as reliable a diagnostic imaging modality in glenohumeral instability as previously thought. Our findings highlight the importance of an accurate history and clinical examination in the management of glenohumeral instability. The need for MRA may not be as high as is currently believed.