Detection and measurement of rotator cuff tears with sonography: analysis of diagnostic errors

OBJECTIVE: The purpose of this study was to analyze the causes of errors in the detection and measurement of rotator cuff tears in our patient population. SUBJECTS AND METHODS: Seventy-one consecutive patients with shoulder pain who were prospectively studied with sonography had subsequent arthroscopy that showed a full-thickness or partial-thickness tear or intact cuff. For sonography and arthroscopy, the length or degree of retraction and width of a tear, when present, was recorded. When there were discrepant findings, representative images were jointly evaluated by the radiologist and orthopedic surgeon to determine the cause of the error. RESULTS: Fifteen detection errors were found, including five misses (three < 5-mm subscapularis and two small partial-thickness tears), four errors inherent with the test (distinguishing large bursal side or extensive partial-thickness from full-thickness tears and tendinopathy from partial-thickness tears), three errors of an unknown cause, two due to misinterpretation, and one error inherent with the patient. Seventeen measurement errors occurred with full-thickness tears, 15 of those in patients with large or massive tears. Bursal thickening (n = 4), non-visualization of the torn tendon end (n = 2), nonretracted tear (n = 2), and complex tear (n = 1) contributed to the errors. Eight measurement errors occurred with partial-thickness tears. Difficulty distinguishing tendinopathy from partial-thickness tears (n = 3) and complex tears (n = 3) accounted for six errors. CONCLUSION: Although infrequent, detection errors were due to limitations inherent with the test or misses. Limitations inherent with the patient and misinterpretation of the findings were rare. Most measurement errors occurred in patients with large or massive cuff tears.     

Gadolinium MR Arthrography of the Rotator Cuff

Conventional magnetic resonance imaging (MRI) of the rotator cuff has not done well in distinguishing partial-thickness tears from tendonitis or small, full-thickness tears. However, these are important distinctions for orthopedic surgeons who are deciding whether to operate and what type of surgery to perform on a patient with suspect rotator cuff pathology. Gadolinium magnetic resonance arthrography (MRA) involves injecting dilute gadolinium into the shoulder under fluoroscopy. Subsequent multiplanar T1-weighted fat-suppressed fast spin echo combined with T2-weighted fast spin echo and short tau inversion recovery (STIR) produces images that can accurately differentiate absence of tear from partial-thickness tear and from small, full-thickness tear; as a fringe benefit, this combination of sequences can identify the inflammation associated with tendonitis. Furthermore, the technique differentiates articular from bursal surface partial-thickness tears, and it accurately quantitates the size of full-thickness tears to help surgeons choose between arthroscopic versus open surgery.     

Ultrasonography of symptomatic rotator cuff tears compared with MR imaging and surgery

Purpose

To compare the accuracy of ultrasonography and magnetic resonance imaging in the detection of rotator cuff tears.

Materials and methods

Ninety-six patients with clinically suspected rotator cuff pathology underwent ultrasonography and magnetic resonance imaging of the shoulder. The findings in 88 patients were compared with arthroscopy or open surgery.

Results

Full-thickness tear was confirmed in 57 cases, partial-thickness tear in 30 cases and degenerative changes without tear in 1. In all 57 cases of full-thickness tear and in 28 out of 30 cases of partial-thickness tear the supraspinatus tendon was involved. The accuracy in the detection of full-thickness tears was 98 and 100% for ultrasonography and magnetic resonance imaging, respectively. The accuracy in the detection of bursal or articular partial-thickness tears was 87 and 90% for ultrasonography and magnetic resonance imaging, respectively.

Conclusions

In experienced hands ultrasonography should be considered as an accurate modality for the initial investigation of rotator cuff, especially supraspinatus, tears.     

Comparison of the MR findings on indirect MR arthrography in patients with rotator cuff tears with and without symptoms

Purpose To compare indirect magnetic resonance (MR) arthrography findings in patients with rotator cuff tears with and without symptoms. Materials and Methods Indirect MR arthrography results of 15 asymptomatic and 23 symptomatic rotator cuff tears were retrospectively reviewed, comparing the type and size of tears and amount of subacrominal-subdeltoid bursal fluid. Results There were 14 partial-thickness tears and one full-thickness tear in the asymptomatic group, with 4 small and 11 medium tears. In the symptomatic group, there were 16 partial-thickness and 7 full-thickness tears, with 14 small, 5medium, and 4 large tears. In the asymptomatic group, the amount of subacrominal-subdeltoid bursal fluid was grade 0, 6 patients; grade 1, 6 patients; grade 2, 2 patients; and grade 3, 1 patient. In the symptomatic group, the amount of subacrominal-subdeltoid bursal fluid was grade 0, 4 patients; grade 1, 3 patients; grade 2, 8 patients; and grade 3, 8 patients. We found no statistically significant difference between symptomatic and asymptomatic tears in the kind and size of tears, and in the amount of subacrominal-subdeltoid bursal fluid. Conclusion We found no difference in the MR findings between symptomatic and asymptomatic rotator cuff tears.     

Cystic changes at supraspinatus and infraspinatus tendon insertion sites: association with age and rotator cuff disorders in 238 patients

PURPOSE: To retrospectively determine the frequency of posterior and anterior cystic abnormalities at rotator cuff insertion site on the greater tuberosity and to determine their relationship to patient age and rotator cuff disorders. MATERIALS AND METHODS: Institutional review board approval was given; informed consent was waived. The study was HIPAA compliant. In 238 patients with rotator cuff diagnoses at surgery, preoperative magnetic resonance (MR) imaging studies were reviewed to localize osseous cystic changes as anterior (supraspinatus insertion site) or posterior (infraspinatus insertion site) on the greater tuberosity. If rotator cuff tear was present, tendon retraction and location of partial tear (articular or bursal surface) were recorded. Two radiologists reached conclusions by consensus. Locations of cysts were correlated to surgical cuff diagnoses: no tear, tendinopathy, partial-thickness tear, and complete tear. Prospective interpretations from original MR reports were compared with surgical results. Statistical analyses included one-way analysis of variance, chi(2), Fisher exact, and Student t tests, as well as logistic regression and receiver operating characteristic curve comparison. RESULTS: There were 238 consecutive patients (150 men, 88 women; mean age, 43 years). Cysts were located at or near footprint of cuff tendon and demonstrated fluid or soft-tissue signal intensities. Posterior cysts occurred in 56.7% of shoulders and showed no statistical correlation to age or cuff diagnosis. Anterior cysts occurred in 22.7% of shoulders and were strongly associated with cuff disorders (P<.001). Controlling for cuff disorders, there was no relationship between anterior cysts and age (P>.50). Anterior cysts were more common in partial-thickness articular (48%) than in bursal (13%) tears (P<.001). CONCLUSION: Posterior cysts were more common than anterior cysts and showed nearly random distribution among patients, regardless of age and cuff diagnosis. Anterior cysts were closely associated with cuff disorders.     

Sonography of the rotator cuff: analysis of interobserver variability

OBJECTIVE: The purpose of our study was to determine the interobserver variability in the sonographic evaluation of the rotator cuff. SUBJECTS AND METHODS: Two radiologists independently scanned 61 patients with shoulder pain. Each radiologist categorized the rotator cuff as normal, partially torn, or fully torn. When a tear was present, the tendons involved were specified. All diagnoses were made prospectively without knowledge of the findings of the other radiologist. RESULTS: The radiologists were in full agreement in the categorization of 92% (56/61) of the patients. In four of the five discrepant cases, the disagreement was whether there was a full-thickness or a partial-thickness tear. The radiologists were in agreement concerning which tendons were involved in 80% (41/51) of the patients in whom a tear was detected by both observers. In all 10 discrepant cases, the disagreement was whether a tear involved both the supraspinatus and infraspinatus tendons or was isolated to one or the other of these tendons. CONCLUSION: The level of interobserver variability in the sonographic detection and characterization of rotator cuff tears is low.     

Greater tuberosity changes as revealed by radiography: lack of clinical usefulness in patients with rotator cuff disease

OBJECTIVE: Studies linking greater tuberosity findings on radiographs with rotator cuff disease have largely been uncontrolled and biased toward more severe disease. We correlated greater tuberosity changes seen on radiography with rotator cuff disease seen on MR images in a broadly symptomatic patient population. MATERIALS AND METHODS: Both radiography and MR imaging were performed in 108 shoulders. Unaware of the MR imaging findings, three radiologists independently reviewed the radiographs for cortical thickening, subcortical sclerosis, and cystlike lesions in the humeral greater tuberosity. Interobserver agreement was analyzed using kappa statistics. We correlated the radiographic findings with MR imaging evidence of rotator cuff tears and tendonopathy. The positive predictive value of each finding for rotator cuff disease was also calculated. RESULTS: Interobserver agreement for the three radiographic findings was poor to fair: Kappa values ranged from .06 to .41. Cortical thickening and subcortical sclerosis were not seen more frequently in shoulders with rotator cuff disease than in normal shoulders. Cystlike lesions were more prevalent in shoulders with rotator cuff disease, but the association reached statistical significance (p < .05) for one observer only. Positive predictive values for each finding were low (14-48% for predicting full-thickness rotator cuff tears). CONCLUSION: Cortical thickening of the greater tuberosity and subcortical sclerosis are not associated with rotator cuff disease. For some observers, identifying cystlike lesions is associated with rotator cuff disease, but the clinical usefulness of the observation is limited by high interobserver variability and poor positive predictive value.     

肩袖损伤的影像学及关节镜诊疗价值

目的探讨肩袖损伤的影像学改变及关节镜检查在诊疗中的价值。方法18例肩袖损伤术前行造影和磁共振成像(MRI)。关节镜手术18例，其中关节镜下肩峰成形减压术16例，小切口肩峰成形2例。全层肩袖损伤10例行小切口肩袖缝合，肩袖部分磨损8例行关节镜下刨削清理术。结果肩关节造影13例，其中9例显示肩关节腔与肩峰下滑囊和三角肌下滑囊沟通，4例未见异常。MRI检查18例，其中10例显示肩袖全层损伤，8例冈上肌腱信号异常为部分损伤。根据关节镜检查结果判断其诊断准确率，MRI为100％，肩关节造影69％。术后随访时间3～22个月，平均7个月。根据美国加州洛杉矶大学(UCLA)肩关节评分标准，优9例，良6例，可3例，优良率达83％。结论肩关节造影有助于全层肩袖损伤的诊断；MRI对肩袖部分和全层损伤正确诊断率和敏感性最高；关节镜治疗肩袖损伤具有微创，有利于功能恢复。     

Repair of full-thickness rotator cuff tears in professional baseball players

BACKGROUND: Despite the relative frequency of partial-thickness rotator cuff tears seen in baseball players, full-thickness rotator cuff tears in baseball players are uncommon. HYPOTHESIS: Return to competitive baseball is difficult after surgical treatment of a full-thickness rotator cuff tear. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We evaluated the results of 16 professional baseball players after a mini-open repair of a full-thickness rotator cuff tear. Twelve patients were pitchers with injury to their dominant shoulders. Four patients were position players; 2 had injuries involving their dominant shoulders, and 2 had injuries to their nondominant shoulders. RESULTS: At a mean follow-up of 66.6 months for the pitchers, only 1 player (8%) was able to return to a high competitive level of baseball with no significant shoulder dysfunction after mini-open repair of a full-thickness rotator cuff tear. Of the 2 position players with mini-open repairs of the full-thickness rotator cuff tear of their dominant shoulders, 1 was able to return to professional baseball. Of the 2 position players with mini-open repairs of the full-thickness rotator cuff tear of their nondominant shoulders, both were able to return to professional baseball at the same or higher level. CONCLUSION: It is very difficult for a professional baseball pitcher to return to a competitive level of pitching after a full-thickness rotator cuff repair with a mini-open approach.     

Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

AIM: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. MATERIALS AND METHODS: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. RESULTS: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p<0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p<0.05). There were no significant differences in coraco-humeral distances between the groups. CONCLUSION: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.     

Arthroscopic transtendon suture-bridge technique for concurrent articular- and bursal-side partial-thickness rotator cuff tears

The transtendon suture-bridge technique is primarily indicated in concurrent articular- and bursal-side partial-thickness rotator cuff tears. The articular aspect of the footprint is restored using the transtendon technique while maintaining the remaining lateral footprint of the rotator cuff. The bursal aspect of the footprint is restored via the suture-bridge technique using the tied suture stands, after applying the transtendon technique while maintaining the remaining medial footprint of the rotator cuff. Using a combination of the transtendon and suture-bridge techniques, the articular and bursal aspects of the footprint are restored while maintaining the remaining footprint of the rotator cuff.     

Learning curve of office-based ultrasonography for rotator cuff tendons tears

Purpose

To compare the accuracy of ultrasonography and MR arthrography (MRA) imaging in detecting of rotator cuff tears with arthroscopic finding used as the reference standard.

Methods

The ultrasonography and MRA findings of 51 shoulders that underwent the arthroscopic surgery were prospectively analysed. Two orthopaedic doctors independently performed ultrasonography and interpreted the findings at the office. The tear size measured at ultrasonography and MRA was compared with the size measured at surgery using Pearson correlation coefficients (r). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and false-positive rate were calculated for a diagnosis of partial-and full-thickness rotator cuff tears. The kappa coefficient was calculated to verify the inter-observer agreement.

Results

The sensitivity of ultrasonography and MRA for detecting partial-thickness tears was 45.5 and 72.7 %, and that for full-thickness tears was 80.0 and 100 %, respectively. The accuracy of ultrasonograpy and MRA for detecting partial-thickness tears was 45.1 and 88.2 %, and that for full-thickness tears was 82.4 and 98 %, respectively. Tear size measured based on ultrasonography examination showed a poor correlation with the size measured at arthroscopic surgery (r = 0.21; p < 0.05). However, tear size estimated by MRA showed a strong correlation (r = 0.75; p < 0.05). The kappa coefficient was 0.47 between the two independent examiners.

Conclusions

The accuracy of office-based ultrasonography for beginner orthopaedic surgeons to detect full-thickness rotator cuff tears was comparable to that of MRA but was less accurate for detecting partial-thickness tears and torn size measurement. Inter-observer agreement on the interpretation was fair. These results highlight the importance of the correct technique and experience in operation of ultrasonography in shoulder joint.

Level of evidence

Diagnostic study, Level II.     

Tear progression of symptomatic full-thickness and partial-thickness rotator cuff tears as measured by repeated MRI

Purpose

The purpose of this study was to analyse the natural course of symptomatic full-thickness and partial-thickness rotator cuff tears treated non-operatively and to identify risk factors affecting tear enlargement.

Methods

One hundred and twenty-two patients who received non-surgical treatment for a partial- or full-thickness supraspinatus tear were included in this study. All rotator cuff tears were diagnosed with magnetic resonance imaging (MRI), and the same modality was used for follow-up studies. Follow-up MRI was performed after at least a 6-month interval. We evaluated the correlation between tear enlargement and follow-up duration. Eleven risk factors were analysed by both univariate and multivariate analyses to identify factors that affect enlargement of rotator cuff tears. The mean follow-up period was 24.4 ± 19.5 months.

Results

Out of 122 patients, 34 (27.9%) patients had an initial full-thickness tear and 88 (72.1%) patients had a partial-thickness tear. Considering all patients together, tear size increased in 51/122 (41.8%) patients, was unchanged in 65/122 (53.3%) patients, and decreased in 6/122 (4.9%) patients. Tear size increased for 28/34 (82.4%) patients with full-thickness tears and 23/88 (26.1%) patients with partial-thickness tears. From the two groups which were followed over 12 months, a higher rate of enlargement was observed in full-thickness tears than in partial-thickness tears (6–12 months, n.s.; 12–24 months, P = 0.002; over 24 months, P < 0.001). Logistic regression revealed that having a full-thickness tear was the most reliable risk factor for tear progression (P < 0.001).

Conclusions

This study found that 28/34 (82.4%) of symptomatic full-thickness rotator cuff tears and 23/88 (26.1%) of symptomatic partial-thickness tears increased in size over a follow-up period of 6–100 months. Full-thickness tears showed a higher rate of enlargement than partial-thickness tears regardless of the follow-up duration. Univariate and multivariate analyses suggested that full-thickness tear was the most reliable risk factor for tear enlargement. The clinical relevance of these observations is that full-thickness rotator cuff tears treated conservatively should be monitored more carefully for progression than partial-thickness tears.

Level of evidence

IV.

     

Ultrasonography of the rotator cuff: a comparison with arthroscopy in one-hundred-and-ninety consecutive cases

PURPOSE: To evaluate the accuracy of high-resolution ultrasonography compared to arthroscopy in the detection of rotator cuff tears. MATERIAL AND METHODS: Preoperative ultrasonography (US) with a 10-MHz commercially available linear-array transducer and a standardized study protocol was performed in 190 consecutive shoulders in 185 patients with a history of shoulder pain for more than 3 months. The findings at US were classified into intact cuff, partial-thickness, and full-thickness rotator cuff tears, and correlated with findings at shoulder arthroscopy. RESULTS: US correctly depicted 118 of 124 rotator cuff tears with sensitivity 95%, specificity 94%, PPV 97%, NPV 91% and accuracy 95%, all 94 full-thickness tears (sensitivity 100%, specificity 91%, PPV 91%, NPV 100%, and accuracy 95%), 24 of 30 partial-thickness tears (sensitivity 80%, specificity 98%, PPV 86%, NPV 96%, and accuracy 95%). CONCLUSION: US is a highly accurate diagnostic method for detecting full-thickness rotator cuff tears, but is less sensitive in detecting partial-thickness rotator cuff tears.     

Angled oblique sagittal MR imaging of rotator cuff tears: comparison with standard oblique sagittal images

Objective. To compare the accuracy for diagnosing rotator cuff tears of oblique coronal images supplemented with standard oblique sagittal images versus thinner-section angled oblique sagittal images. Design and patients. The study included 75 consecutive patients who had a shoulder MR scan followed by arthroscopy. MR images included oblique coronal, oblique sagittal (4 mm thick, 1 mm interslice gap), and angled oblique sagittal (3 mm/0.2 mm) images perpendicular to the lateral cuff. A musculoskeletal staff radiologist and fellow separately evaluated the cuff for tears on the oblique coronal images supplemented with either the oblique sagittal or the angled sagittal images. Results. For distinguishing a cuff tear from no tear, the staff radiologist had an accuracy of 0.76 (95% confidence interval: 0.67, 0.85) with the standard sagittal set, and 0.88 (0.80, 0.95) with the angled set (P=0.04). There was a nonsignificant improvement in accuracy for the fellow, calculated as 0.73 (0.63, 0.83) on the standard sagittal set and 0.76 (0.67, 0.85) on the angled set. Both readers also improved their diagnostic accuracy for partial-thickness tears with the angled set, although the improvement was statistically significant only for the staff radiologist. Conclusion. There is a slight improvement in accuracy for diagnosing rotator cuff tears, particularly partial-thickness tears, for the more experienced radiologist using thinner-section angled oblique sagittal images. These images may be useful as a supplemental sequence in patients where it is important to identify partial-thickness tears accurately. Received: 7 August 2000 Revision requested: 13 October 2000 Revision received: 27 November 2000 Accepted: 12 December 2000     

Ultrasonography for diagnosis of rotator cuff tear

 In this study the clinical usefulness of ultrasonography in the diagnosis of rotator cuff tears was assessed. One hundred twenty-two patients undergoing preoperative ultrasonography were evaluated surgically. Three different ultrasonographic machines were applied with a 7.5-MHz linear-array transducer. Surgery confirmed a sensitivity of 79% for full-thickness tears and 50% for partial thickness tears. In 73 patients with negative ultrasonographic findings, the specifity was 100% for full-thickness tears and 90% for partial-thickness tears. The diagnostic sensitivity for full-thickness tears of the Hitachi EUB-340 system was significantly lower than those of Hitachi EUB-415 and EUB-515, and thus the former cannot be recommended for detection of rotator cuff tears. The sensitivity with regard to partial-thickness tears was also significantly lower with the Hitachi EUB-340 system as compared to the Hitachi EUB-515. There were no significant differences in false-positive rate among the three machines used. In conclusion, accurate ultrasonographic diagnosis of rotator cuff tear requires a high-resolution machine, as well as considerable experience in interpretation.     

Rotator cuff tears: assessment with MR arthrography in 275 patients with arthroscopic correlation

We assessed the diagnostic performance of magnetic resonance (MR) arthrography in the diagnosis of articular-sided partial-thickness and full-thickness rotator cuff tears in a large symptomatic population. MR arthrograms obtained in 275 patients including a study group of 139 patients with rotator cuff tears proved by arthroscopy and a control group of 136 patients with arthroscopically intact rotator cuff tendons were reviewed in random order. MR imaging was performed on a 1.0 T system (Magnetom Expert, Siemens). MR arthrograms were analyzed by two radiologists in consensus for articular-sided partial-thickness and full-thickness tears of the supraspinatus, infraspinatus, and subscapularis tendons. At arthroscopy, 197 rotator cuff tears were diagnosed, including 105 partial-thickness (93 supraspinatus, nine infraspinatus, three subscapularis) and 92 full-thickness (43 supraspinatus, 20 infraspinatus, 29 subscapularis) tendon tears. For full-thickness tears, sensitivity, specificity, and accuracy were 96%, 99%, and 98%, respectively, and for partial tears 80%, 97%, and 95%, respectively. False negative and positive assessments in the diagnosis of articular-sided partial-thickness tears were predominantly [78% (35/45)] observed with small articular-sided (Ellman grade1) tendon tears. MR arthrography is highly accurate in the diagnosis of full-thickness rotator cuff tears and is accurate in the diagnosis of articular-sided partial-thickness tears. Limitations in the diagnosis of partial-thickness tears are mainly restricted to small articular-sided tears (Ellman grade 1) due to difficulties in differentiation between fiber tearing, tendinitis, synovitic changes, and superficial fraying at tendon margins.     

Sonography of the painful shoulder: role of the operator’s experience

Objective  The aim of our study was to determine the role of the operator’s experience in the sonographic evaluation of the painful shoulder and to validate assumptions about its technical performance in routine practice. Materials and methods  Two radiologists, respectively standard and expert sonographic operators, independently and prospectively scanned 65 patients with clinical suspicion of rotator cuff lesion. Magnetic resonance arthrography was the reference standard. Results  The sensitivity of the expert ultrasound operator was 95.3% for full-thickness rotator cuff tears (41/43), 70.6% for partial-thickness tears (12/17), 64.3% for intratendinous tears (9/14), 100% for abnormality of the long head of biceps tendon (seven of seven), 88.9% for supraspinatus tendinosis (16/18), 96.4% for subacromial bursa abnormalities (53/55), and 91.7% for acromioclavicular joint osteoarthritis (33/36). The two sonographic operators were in very good agreement about full-thickness rotator cuff tears (κ = 0.90), supraspinatus tendinosis (κ = 0.80), abnormalities of the long head of biceps tendon (κ = 0.84), subacromial bursa abnormalities (κ = 0.89), and acromioclavicular osteoarthritis (κ = 0.81). The agreement was only moderate for partial-thickness tears (κ = 0.63) and intratendinous tears (κ = 0.57). Conclusions  Our results show that in moderately experienced hands as in experts’ hands, sonography has a low level of interobserver variability for full-thickness rotator cuff tears. Considering partial-thickness and intratendinous rotator cuff tears, our data suggest that interobserver variability is higher.     

Comparisons of the Various Partial-Thickness Rotator Cuff Tears on MR Arthrography and Arthroscopic Correlation

Objective

To assess the diagnostic performance of MR arthrography in the diagnosis of the various types of partial-thickness rotator cuff tears by comparing the MR imaging findings with the arthroscopic findings.

Materials and Methods

The series of MR arthrography studies included 202 patients consisting of 100 patients with partial-thickness rotator cuff tears proved by arthroscopy and a control group of 102 patients with arthroscopically intact rotator cuffs, which were reviewed in random order. At arthroscopy, 54 articular-sided, 26 bursal-sided, 20 both articular- and bursal-sided partial-thickness tears were diagnosed. The MR arthrographies were analyzed by two radiologists for articular-sided tears, bursal-sided tears, and both articular- and bursal-sided tears of the rotator cuff. The sensitivity and specificity of each type of partial-thickness tears were determined. Kappa statistics was calculated to determine the inter- and intra-observer agreement of the diagnosis of partial-thickness rotator cuff tears.

Results

The sensitivity and specificity of the various types of rotator cuff tears were 85% and 90%, respectively for articular-sided tears, 62% and 95% for bursal-sided tears, as well as 45% and 99% for both articular- and bursal-sided tears. False-negative assessments were primarily observed in the diagnosis of bursal-sided tears. Conversely, both articular- and bursal-sided tears were overestimated as full-thickness tears. Inter-observer agreement was excellent for the diagnosis of articular-sided tears (k = 0.70), moderate (k = 0.59) for bursal-sided tears, and fair (k = 0.34) for both articular- and bursal-sided tears, respectively. Intra-observer agreement for the interpretation of articular- and bursal-sided tears was excellent and good, respectively, whereas intra-observer agreement for both articular- and bursal-sided tears was moderate.

Conclusion

MR arthrography is a useful diagnostic tool for partial-thickness rotator cuff tears, but has limitations in that it has low sensitivity in bursal- and both articular- and bursal-sided tears. In addition, it shows only fair inter-observer agreement when it comes to predicting both articular- and bursal-sided tears.     

The rotator cuff functional index

BACKGROUND: Despite improvements in the clinical assessment of rotator cuff injuries, shortcomings exist in diagnosing rotator cuff tears. PURPOSE: To formulate a clinical rotator cuff functional index for predicting rotator cuff tears based on handheld dynamometer measurements for shoulder strength testing and to assess its ability to diagnose a rotator cuff tear. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Preoperative handheld dynamometer measurements, including supraspinatus, external rotation, internal rotation, adduction, and lift-off force, were compared in 100 patients with full-thickness rotator cuff tears (> 1.0 cm) and 100 patients with no rotator cuff injury (confirmed by arthroscopy). Using multiple logistic regression analysis, the rotator cuff functional index and index for rotator cuff tear size were formulated in which 100 represented excellent rotator cuff function and less than 0 indicated a full-thickness supraspinatus tear. Each patient's index was calculated to determine its clinical value in predicting a rotator cuff tear; the Pearson correlation coefficient was established for the rotator cuff functional index for rotator cuff size. RESULTS: Two handheld dynamometer measurements predicted a rotator cuff tear (P < .001, r = 0.53), with rotator cuff functional index = 1.27 * supraspinatus (N) - 0.72 * adduction (N) - 11.6, but not tear size (r = 0.38). In predicting a rotator cuff tear (rotator cuff functional index < 0 = rotator cuff tear; rotator cuff functional index > 0 = no tear), the rotator cuff functional index had 83% sensitivity, 79% specificity, 80% positive predictive value, 82% negative predictive value, likelihood ratio of 4.0 for a positive test result and 0.2 for a negative test result and an accuracy of 81%. CONCLUSION: The 2 most useful tests for determining a rotator cuff tear with a handheld dynamometer were supraspinatus force and adduction force (as negative control). A functional index based on these measurements was able to rule out a rotator cuff tear and predict the presence but not the size of the tear.