Shoulder sonography: why we do it

[Postoperative Imaging of Rotator Cuff Tear]

Postoperative imaging of the rotator cuff may be performed routinely, even if pain or disability develops after surgery or if there are no symptoms. Postoperative images are obtained through MRI or US, and the purpose is to confirm the integrity of the restored tendon in general. Postoperative MRI has a relatively poor diagnostic accuracy compared to that of preoperative images because various materials used in surgeries deteriorate the image quality. US can dynamically check the condition of the restored tendon and avoid artifacts from the surgical instruments used for recovery. Although imaging findings are not always consistent with the clinical symptoms or prognosis, sub-deltoid fluid retention is more important for pain and functional recovery than the thickness of the reconstructed tendon. Strain elastography can also be a useful method for predicting the prognosis.

Diagnostic Ultrasound Shows Reversal of Supraspinatus Muscle Atrophy Following Arthroscopic Rotator Cuff Repair

PURPOSE

Prospective study to assess ultrasonography (US) utility as an imaging tool for supraspinatus muscle atrophy diagnosis, establishing if there is any relationship between repairing supraspinatus tears and its eventual muscular recovery.

METHODS

Observational study.

SELECTION CRITERIA

adults with a full-thickness reparable supraspinatus tear confirmed arthroscopically. Clinical and imaging data pre- and postoperatively with 12 months of follow-up were recorded, including demographic data, Constant scale, Patte classification, repair type, and supraspinatus muscle belly US images in both shoulders, recording height, diameter, echogenicity (mean number of pixels between 0-black and 255-white), and central tendon pennate angle (PA).

RESULTS

In total, 110 supraspinatus tears underwent arthroscopic repair (2015-2018). Mean age was 61 ± 8 years (46-77). We detected a correlation between atrophy and age in terms of echogenicity and PA (P = .01). Echogenicity improved from 54.5 to 51.0 (P = .365) and slightly deteriorated on the contralateral side from 51.6 to 52.9 (P = .351). Supraspinatus echogenicity compared to trapezius muscle reduced from 0.43 to 0.36 (P < .001). PA augmented from 5.8 to 8.6 (P < .001). Mean PA on the contralateral side was 8.6 preoperatively. Patte II cases showed the most significant improvement in terms of imaging evaluation of atrophy. Although Patte III cases almost did not improve in terms of atrophy, they improved clinically. We observed improvement after surgery in Constant score from 35 to 85 (P < .001). Minimal clinically important differences for Constant and visual analog scale were 44.45 ± 12.87 and 6.54 ± 1.41, respectively. Recurrence of symptoms was 13%, related to worse results of PA and echogenicity compared to nonrecurrences.

CONCLUSIONS

Supraspinatus atrophic muscle changes after repair can be reversed. It can be quantified using US imaging (histogram, histogram ratio and echogenicity reduction, pennate pattern, and PA augmentation). Patte II cases showed the best results after repair, demonstrated by US. The faster the repair, the better the results without being influenced by repair type. The bigger the tear and retraction, the more echogenicity and less PA, with worse clinical and US results.

LEVEL OF EVIDENCE

Level III, prospective therapeutic study.

Method Comparison for Detection and Measurement of Rotator Cuff Tears: Office-based Bedside Ultrasonography by a Single Physiatrist versus Imaging Center-based Ultrasonography by Two Expert Musculoskeletal Radiologists

INTRODUCTION

There is increasing interest among physiatrists in using bedside ultrasonography to assess rotator cuff tears.

OBJECTIVE

To conduct a method comparison between ultrasonography performed by a single physiatrist at bedside and two validated expert musculoskeletal radiologists at an imaging center.

DESIGN

Prospective, blinded comparison study.

SETTING

Academic outpatient clinic and imaging center.

PATIENTS

Seventy-two unilateral shoulders were scanned. Inclusion criteria included pain or weakness with rotator cuff testing and compliance with repeat ultrasonography.

INTERVENTIONS

Ultrasonography performed by the physiatrist was done at bedside during the patient's clinical visit, while the radiologists' scan was performed afterwards in an imaging center. The radiologists trained the physiatrist who was performing the scans.

MAIN OUTCOME MEASUREMENTS

The primary outcome was integrity of the rotator cuff (intact, partial tear, full tear). When a posterior cuff (supraspinatus, infraspinatus, teres minor) tear was detected, measurements of length, width, and distance from the biceps tendon were taken.

RESULTS

With use of the radiologists' scan as a criterion standard, bedside ultrasonography performed by the physiatrist for detection of posterior cuff tears had a percent perfect agreement of 72.2% for categorization as no tear, partial tear, or full tear. When evaluating dichotomously for presence of a full tear, sensitivity was 82.1% and specificity was 93.9%. Seven (18%) full-thickness tears were missed, and all were essentially small (<15 mm). When physiatrist and radiologist measurements were compared, the mean ± standard deviation (SD) difference in length was 3.4 ± 4.7 mm, width was 2.7 ± 6.7 mm, and distance to the biceps tendon was -0.8 ± 7.5 mm.

CONCLUSIONS

Office-based bedside ultrasonography is a reasonable modality to rule out medium/large full-thickness posterior cuff tears. However, physicians should be aware that a percentage of small full-thickness tears can be missed. Further imaging should be considered in suspected partial tears and full tears that may be appropriate for surgical repair.

Axillary Sonography of the Shoulder: An Adjunctive Approach

Sonography of the shoulder is widely used to assess various disorders, including tendinous diseases of the rotator cuff and the long head of the biceps brachii muscle. The shoulder is commonly explored through anterior, superior, and posterior approaches, but the inferior axillary approach is rarely considered in the literature. However, this technique allows the direct visualization of relevant anatomic structures. The aim of this pictorial essay is, first, to technically describe this approach and the normal musculoskeletal sonographic anatomy of the region and, second, to present the sonographic findings of shoulder disorders that may be helpfully explored this technique.

Ultrasonographic Findings in 41 Dogs Treated with Bone Marrow Aspirate Concentrate and Platelet-Rich Plasma for a Supraspinatus Tendinopathy: A Retrospective Study

Objective

To report sonographic findings for dogs with a supraspinatus tendinopathy (ST) treated with an ultrasound-guided intratendinous injection of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP).

Methods

Medical records for dogs diagnosed with an ST and treated with a BMAC-PRP injection were reviewed. Data collected included patient signalment, radiographic findings at the time of initial evaluation, and sonographic findings, including cross-sectional area (CSA), fiber pattern, and echogenicity.

Results

Of 70 records reviewed, 41 met the inclusion criteria. Mean CSA of the supraspinatus tendon decreased by 0.06 cm² between baseline and 45 days post-treatment (p = 0.0025), and 0.09 cm² between baseline and 90 days post-treatment (p < 0.0001). Analysis of CSA in dogs with a unilateral ST at baseline revealed a difference of 0.08 cm² between the affected and unaffected tendon at baseline, with the affected tendon measuring larger than the contralateral tendon (p < 0.0001). This difference became statistically insignificant by 45 days after treatment (u₁-u₀ = 0.04 cm², p = 0.2855) and remained so 90 days post-treatment (u₁-u₀ = 0.03 cm², p = 0.1910). In most cases (90.6%), the fiber pattern and echogenicity was considered improved 90 days post treatment. In a minority of these cases (13.8%) the fiber pattern and echogenicity abnormalities were considered resolved.

Conclusions

Using qualitative and quantitative sonographic measures, BMAC-PRP was associated with an improvement in supraspinatus tendon size, fiber pattern, and echogenicity. Given the protracted nature of tendon healing, long-term evaluation may reveal continued improvements in chronic structural changes not captured during the current study. Functional studies are required to evaluate the clinical benefits of BMAC-PRP in the treatment of STs in dogs.

Clinical significance

An ST is a common contributor to forelimb lameness in dogs and remains notoriously difficult to treat. Previous studies have been associated with inconsistent treatment outcomes. In the current study, BMAC-PRP is investigated as a minimally invasive treatment option, revealing positive sonographic results.

Comprehensive Shoulder US Examination: A Standardized Approach with Multimodality Correlation for Common Shoulder Disease

Shoulder pain is one of the most common musculoskeletal conditions encountered in primary care and specialty orthopedic clinic settings. Although magnetic resonance (MR) imaging is typically the modality of choice for evaluating the soft-tissue structures of the shoulder, ultrasonography (US) is becoming an important complementary imaging tool in the evaluation of superficial soft-tissue structures such as the rotator cuff, subacromial-subdeltoid bursa, and biceps tendon. The advantages of US driving its recent increased use include low cost, accessibility, and capability for real-time high-resolution imaging that enables dynamic assessment and needle guidance. As more radiologists are considering incorporating shoulder US into their practices, the development of a standardized approach to performing shoulder US should be a priority to facilitate the delivery of high-quality patient care. Familiarity with and comfort in performing a standardized shoulder US examination, as well as knowledge of the types of anomalies that can be evaluated well with US, will enhance the expertise of those working in musculoskeletal radiology practices and add value in the form of increased patient and health care provider satisfaction. This review describes the utility and benefits of shoulder US as a tool that complements MR imaging in the assessment of shoulder pain. A standardized approach to the shoulder US examination is also described, with a review of the basic technique of this examination, normal anatomy of the shoulder, common indications for shoulder US, and characteristic US findings of common shoulder diseases-with select MR imaging and arthroscopic correlation. Online supplemental material is available for this article. ^©RSNA, 2016.

Sonographic Evaluation of Structural Changes in Post-Stroke Hemiplegic Shoulders

Background

Stroke and hemiplegia are frequent complications of stroke. This study was performed to sonographically evaluate post-stroke hemiplegic shoulders and explore possible relationship(s) between the sonographic findings and clinical indices.

Material/Methods

Forty-five stroke patients and 45 age- and sex-matched controls were recruited. Standard sonographic examination of both shoulders was performed to assess for joint subluxation, rotator cuff tears, tendinosis, subacromial-subdeltoid bursitis or effusion and adhesive capsulitis.

Results

Hemiplegic shoulders exhibited significantly higher number of pathologies compared to the unaffected shoulders and shoulders of controls (p=0.000). One or more structural abnormalities were found in all 45 (100%) hemiplegic shoulders, 25 (55.6%) unaffected shoulders of the stroke subjects, and 39 (43.3%) control shoulders. The most frequent pathologies in the hemiplegic shoulders were the following: tendinosis of the long head of bicep tendon (48.9%), inferior shoulder subluxation (44.4%), co-existing subacromial-subdeltoid bursa/long head of bicep tendon sheath effusion (44.4%), and long head of bicep tendon sheath effusion only (40%). Tendinosis of the long head of bicep tendon was commoner in hemiplegic shoulders with poor motor status than those with good motor status.

Conclusions

Hemiplegic shoulders have significantly higher number of structural abnormalities than unaffected shoulders and the shoulders of controls. Hemiplegic stroke patients should undergo ultrasonography of the hemiplegic shoulder to define the nature and extent of soft tissue injuries prior to physical therapy.

Characterization of Rotator Cuff Tears: Ultrasound Versus Magnetic Resonance Imaging

Ultrasound and magnetic resonance imaging (MRI) are both capable of diagnosing full-thickness rotator cuff tears. However, it is unknown which imaging modality is more accurate and precise in evaluating the characteristics of full-thickness rotator cuff tears in a surgical population. This study reviewed 114 patients who underwent arthroscopic repair of a full-thickness rotator cuff tear over a 1-year period. Of these patients, 61 had both preoperative MRI and ultrasound for review. Three musculoskeletal radiologists evaluated each ultrasound and MRI in a randomized and blinded fashion on 2 separate occasions. Tear size, retraction status, muscle atrophy, and fatty infiltration were analyzed and compared between the 2 modalities. Ultrasound measurements were statistically smaller in both tear size (P=.001) and retraction status (P=.001) compared with MRI. The 2 image modalities showed comparable intraobserver reliability in assessment of tear size and retraction status. However, MRI showed greater interobserver reliability in assessment of tear size, retraction status, and atrophy. Independent observers are more likely to agree on measurements of the characteristics of rotator cuff tears when using MRI compared with ultrasound. As tear size increases, the 2 image modalities show greater differences in measurement of tear size and retraction status. Additionally, compared with MRI, ultrasound shows consistently low reliability in detecting subtle, but clinically important, degeneration of the soft tissue envelope. Although it is inexpensive and convenient, ultrasound may be best used to identify a tear, and MRI is superior for use in surgical planning for larger tears. [Orthopedics. 2017; 40(1):e124-e130.].

Evaluating postoperative rotator cuff healing: Prospective comparison of MRI and ultrasound

BACKGROUND

The objective of this prospective comparative single centre study was to compare postoperative rotator cuff healing rates as assessed by magnetic resonance imaging (MRI) versus ultrasonography (US).

MATERIAL AND METHODS

Between October 2012 and February 2013, 61 patients underwent arthroscopic repair of postero-superior rotator cuff tears. Each patient underwent MRI and US 6 months later. The findings were assessed independently by two observers. We compared intra-observer and inter-observer levels of agreement regarding healing rates assessed by MRI and US.

RESULTS

Intra-observer agreement regarding the MRI interpretation was 95% (κ coefficient, 0.83) for one observer and 98% (κ coefficient, 0.94) for the other. Values of κ for inter-observer agreement ranged across readings from 0.76 to 0.90. When MRI was taken as the reference, US had 80% sensitivity and 98% specificity.

DISCUSSION

MRI and US provide similar assessments of postoperative rotator cuff healing, although US is less sensitive. Intra-observer and inter-observer agreements are very good.

Do subacromial ultrasonography findings predict efficacy of intra-bursal injection? Prospective study in 39 patients

BACKGROUND

Ultrasonography has become an investigation of choice in the management of shoulder pain. The objective of this study was to determine whether the efficacy of subacromial-subdeltoid bursa injection correlated with the ultrasound findings.

MATERIAL AND METHODS

We prospectively recruited patients who were seen between November 2012 and November 2013 for subacromial pain and whose rotator cuff was either intact or showed a full-thickness tear less than 1cm in length. A standardised physical examination of the shoulder was followed immediately by static and dynamic ultrasonography, intra-bursal injection of lidocaine, and a repetition of the same physical examination. Recorded ultrasonography features were the appearance of the bursa, shape of the coraco-acromial ligament, and bursal deformation induced by passage under the coraco-acromial ligament during dynamic imaging. A response to the injection was defined as greater than 75% improvements in at least three of the physical examination parameters.

RESULTS

We included 39 patients with a mean age of 56.7 years. Ultrasonography showed abnormalities of the bursa in 30 patients, including 1 with an intra-bursal effusion, 10 with thickening, and 19 with both. Deformation of the bursa under the coraco-acromial ligament was noted in 26 patients. The proportions of patients with bursal effusion and with bursal thickening were similar in the 20 responders and 19 non-responders. Neither were any significant differences found for coraco-acromial ligament shape or bursal deformation under the ligament.

CONCLUSIONS

No correlation was found between ultrasonography findings and the efficacy of a local anaesthetic injection into the subacromial bursa. These findings suggest that ultrasound abnormalities may constitute mere physiological changes, in keeping with earlier studies in asymptomatic individuals. Thus, subacromial impingement may be currently overdiagnosed.

Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study

BACKGROUND

This study compared ultrasound and magnetic resonance imaging (MRI) evaluation of the repaired rotator cuff to determine concordance between these imaging studies.

METHODS

We performed a concordance study using the data from a prospective nonrandomized multicenter study at 13 centers. A suture bridge technique was used to repair 113 rotator cuff tears that were between 1 and 4 cm wide. Repairs were evaluated with MRI and ultrasound at multiple time points after surgery. The MRI scans were read by a central radiologist and the surgeon, and the ultrasounds were read by a local radiologist or the surgeon who performed the ultrasound.

RESULTS

The concordance between the central radiologist's MRI reading and the investigator's MRI readings at all time points was 89%, with a κ coefficient of 0.60. The concordance between the central radiologist's MRI and ultrasound readings at all time points was 85%, with a κ coefficient of 0.40. The concordance between the investigator's MRI and ultrasound readings was 92%, with a κ coefficient of 0.70.

CONCLUSIONS

In the community setting, ultrasound may be used to evaluate the integrity of a repaired rotator cuff tendon and constitutes a comparable alternative to MRI when evaluating the integrity of a rotator cuff repair. Clinical investigators should compare their postoperative ultrasound results with their postoperative MRI results for a certain time period to establish the accuracy of ultrasound before relying solely on ultrasound imaging to evaluate the integrity of their rotator cuff repairs.