What is the place of ultrasound in MSK imaging?

During the past four decades, ultrasound has become popular as an imaging modality applied to the musculoskeletal (MSK) system, particularly outside the USA, due to its low cost, accessibility, and lack of ionizing radiation. A basic requirement in performing these examinations is to have a core group of radiologists and ultrasound technologists with expertise in MSK ultrasound. The extent to which ultrasound will be part of the imaging offered by a particular radiology practice or in an academic institution will vary according to expertise, availability, and reimbursements. A brief discussion of the technical capabilities of the current generation of ultrasound scanners will be followed by a description of some of the more prevalent MSK ultrasound imaging applications. The extent to which training to perform these exams within and outside of Radiology plays a role is discussed. Applications that are unique to ultrasound, such as dynamic evaluation of musculoskeletal anatomy and some, US-guided interventions are an important part of MSK imaging. Ultrasound is increasingly important in the assessment of superficial structures, such as tendons, small joints, and peripheral nerves. These applications help to establish the place of ultrasound as an important part of the Radiologists approach to MSK imaging. Outside of radiology, for a variety of clinical subspecialties, ultrasound already plays an integral role in MSK imaging.

Pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis: a case report

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

Tips and tricks in ultrasound-guided musculoskeletal interventional procedures

Ultrasound visualization affords proceduralists versatile and accurate guidance for a variety of percutaneous, minimally invasive procedures in the musculoskeletal system including joint (intra-articular) injections or aspirations, intra-bursal injections, peritendinous, and perineural injections. A variety of percutaneous procedures are traditionally performed blindly, but may be more easily or more accurately performed with the real-time assistance of ultrasound guidance. Other procedures are only possible utilizing image-guidance, due to the required precision of the injection because of delicate local anatomy or depth of the injection; ultrasound is a safe, portable, and widespread modality that can be used to assist the proceduralist in localizing the needle tip in such cases, to ensure safe and accurate delivery of the medication, most frequently a solution of steroid and anesthetic. This review aims to provide a foundational approach to ultrasound-guided procedures in the musculoskeletal system, offering tips and tricks that can be employed in many different procedures including intra-articular, juxta-articular, and perineural injections for a multitude of clinical scenarios. Technical considerations regarding ultrasound transducer selection, sonographic technique, as well as common indications, contraindications, and complications of these procedures, are presented. Additionally, a variety of pharmacologic considerations for proceduralists contemplating ultrasound-guided injections are discussed.

Brachial Plexus Nerve Injuries and Disorders

Multimodality imaging of the brachial plexus is essential to accurately localize the lesion and characterize the pathology and site of injury. A combination of computed tomography (CT), ultrasound, and MR imaging is useful along with clinical and nerve conduction studies. Ultrasound and MR imaging in combination are effective to accurately localize the pathology in most of the cases. Accurate reporting of the pathology with dedicated MR imaging protocols in conjunction with Doppler ultrasound and dynamic imaging provides practical and useful information to help the referring physicians and surgeons to optimize medical or surgical treatment regimens.

Interventional Imaging Techniques as Alternative to Surgery of the Foot and Ankle

A variety of foot and ankle pathologies can impair patient's daily activities, ultimately requiring surgical management. However, with improvements in image-guided intervention, the joints, soft tissues, and osseous structures may be accessible using various percutaneous techniques as a potential alternative therapeutic tool, avoiding the need for surgery with its associated risks and morbidity. This article discusses the potential range of image-guided interventional treatments. Injections, aspiration, biopsies, cryoablation, and radiofrequency ablation are described. Newer novel treatments are also covered. Finally, the common pathologies of Morton's neuroma, Achilles tendinopathy, and plantar fasciitis are addressed.

Incidence of infectious complications following ultrasound-guided percutaneous musculoskeletal interventions with the use of an uncovered transducer footprint

OBJECTIVES

To determine the incidence of infectious complications following ultrasound-guided musculoskeletal interventions performed with a disinfected uncovered ultrasound transducer footprint.

METHODS

Electronic medical records of all patients who underwent an ultrasound-guided musculoskeletal procedure (including injection, calcific lavage, or ganglion cyst aspiration) performed by any of the 14 interventional musculoskeletal radiologists at our institution between January 2013 and December 2018 were retrospectively reviewed to identify procedure site infections. Biopsies and joint aspirations were excluded. The procedures were performed using a disinfected uncovered transducer footprint. First, an automated chart review identified cases with (1) positive answers to the nurse's post-procedure call, (2) an International Classification of Diseases (ICD) diagnostic code related to a musculoskeletal infection, or (3) an antibiotic prescription within 30 days post-procedure. Then, these cases were manually reviewed for evidence of procedure site infection.

RESULTS

In total, 6511 procedures were included. The automated chart review identified 3 procedures (2 patients) in which post-procedural fever was reported during the nurse's post-procedure call, 33 procedures (28 patients) with an ICD code for a musculoskeletal infection, and 220 procedures (216 patients) with an antibiotic prescription within 30 post-procedural days. The manual chart review of these patients revealed no cases of confirmed infection and 1 case (0.015%) of possible site infection.

CONCLUSIONS

The incidence of infectious complications after an ultrasound-guided musculoskeletal procedure performed with an uncovered transducer footprint is extremely low. This information allows radiologists to counsel their patients more precisely when obtaining informed consent.

KEY POINTS

• Infectious complications after ultrasound-guided musculoskeletal procedures performed with a disinfected uncovered transducer footprint are extremely rare.

Ultrasound-Guided Musculoskeletal Injections

Musculoskeletal injections serve a variety of diagnostic and therapeutic purposes, with ultrasonography (US) guidance having many advantages: no ionizing radiation, real-time guidance, high spatial resolution, excellent soft tissue contrast, and the ability to identify and avoid critical structures. Sonography can be cost effective and afford flexibility in resource-constrained settings. This article describes US-guided musculoskeletal injections relevant to many radiology practices and provides experience-based suggestions. Structures covered include multiple joints (shoulder, hip), bursae (iliopsoas, subacromial-subdeltoid, greater trochanteric), peripheral nerves (sciatic, radial), and tendon sheaths (posterior tibial, peroneal, flexor hallucis longus, Achilles, long head of the biceps). Trigger point and similar targeted steroid injections, as well as calcific tendinopathy barbotage, are also described.

Ultrasound of the symptomatic shoulder arthroplasty: Spectrum and prevalence of periarticular soft tissue pathology

PURPOSE

To describe our experience using ultrasound (US) to evaluate postoperative complications in the presence of in situ shoulder arthroplasty.

METHODS

Review of patients who underwent US evaluation following total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA) or hemiarthroplasty from 2007 to 2020. All studies were reviewed independently by two musculoskeletal radiologists to assess for joint effusion, periarticular collection, and characterization of associated rotator cuff tears. Tendon tears were assessed with respect to (1) thickness: low grade (<50% thickness), high grade (>50% thickness), full thickness; (2) morphology (focal vs. diffuse) and location (insertion vs. critical zone). Inter-reader agreements were determined using Cohen's kappa test.

RESULTS

Ninety-seven studies were performed in 72 patients following TSA, RTSA, or hemiarthroplasty. Thirty-seven exams were solely for diagnostic purposes, and 59 were for guiding joint or periarticular collection aspiration. Twenty-eight studies assessed the cuff tendons post TSA. The mean time between surgery and US examination was 29.2 months. Complete or high-grade tears were identified in 8/28 (28.6%) diagnostic exams. The most commonly torn tendon among TSA patients was the subscapularis, with 13/28 (46.4%) demonstrating at least partial tearing. Inter-reader agreement was excellent for presence of effusion (k = 0.79, p < .001) and periarticular collection (k = 0.87, p < .001), and excellent agreement for presence of subscapularis tear (k = 0.78, p < .001), with fair agreement for assessment of supraspinatus (k = 0.66, p < .001) and infraspinatus (k = 0.60, p < .001) tears.

CONCLUSION

The most commonly torn tendon following anatomic TSA identified by US was the subscapularis, which was torn or deficient in 46.4% of cases. The majority of studies were performed for the guidance of percutaneous aspiration.

Ultrasound-MRI Correlation for Healing of Rotator Cuff Repairs Using Power Doppler, Sonographic Shear Wave Elastography and MR Signal Characteristics: A Pilot Study

OBJECTIVE

To determine whether the healing response in rotator cuff repairs can be quantitatively characterized using a multimodality imaging approach with MR signal intensity, power Doppler and shear wave elastography (SWE).

MATERIALS AND METHODS

Patients scheduled for rotator cuff repair were prospectively enrolled between September 2013 and June 2016. A 12 patient cohort with unilateral, full-thickness, supraspinatus tendon tears underwent MRI and ultrasound both preoperatively and postoperatively (at 3 and 6 months post-surgery). The MR signal intensity ratio of tendon-to-deltoid muscle (TMR), vascularity score by power Doppler (PD) and shear wave velocity (SWV) were measured. Repaired and asymptomatic control shoulders were compared over time and between modalities.

RESULTS

TMR and vascularity of the tendon repair initially increased and then decreased postoperatively. Although not achieving statistical significance, postoperative SWV initially decreased and later increased, which negatively correlated with the TMR at 3 months (r = -0.73, p = 0.005). PD demonstrated a statistically significant change in tendon vascularity over time compared to the contralateral control (p = 0.009 at 3 months; p = 0.036 at 6 months). No significant correlation occurred between TMR and SWE at 6 months, or with PD at any time point.

CONCLUSION

Despite a small patient cohort, this prospective pilot study suggests a temporal relationship of MRI and ultrasound parameters that parallels the expected phases of healing in the repaired rotator cuff.

Does Magnetic Resonance Imaging After Diagnostic Ultrasound for Soft Tissue Masses Change Clinical Management?

OBJECTIVES

To evaluate whether a follow-up magnetic resonance imaging (MRI) scan performed after initial ultrasound (US) to evaluate soft tissue mass (STM) lesions of the musculoskeletal system provides additional radiologic diagnostic information and alters clinical management.

METHODS

A retrospective chart review was performed of patients undergoing initial US evaluations of STMs of the axial or appendicular skeleton between November 2012 and March 2019. Patients who underwent US examinations followed by MRI for the evaluation of STM lesions were identified. For inclusion, the subsequent pathologic correlation was required from either a surgical or image-guided biopsy. Imaging studies with pathologic correlations were then reviewed by 3 musculoskeletal radiologists, who were blinded to the pathologic diagnoses. The diagnostic utility of MRI was then assessed on the basis of a 5-point grading scale, and inter-reader agreements were determined by the Fleiss κ statistic.

RESULTS

Ninety-two patients underwent MRI after US for STM evaluations. Final pathologic results were available in 42 cases. Samples were obtained by surgical excision or open biopsy (n = 34) or US-guided core biopsy (n = 8). The most common pathologic diagnoses were nerve sheath tumors (n = 9), lipomas (n = 5), and leiomyomas (n = 5). Imaging review showed that the subsequent MRI did not change the working diagnosis in 73% of cases, and the subsequent MRI was not considered to narrow the differential diagnosis in 68% of cases. There was slight inter-reader agreement for the diagnostic utility of MRI among individual cases (κ = 0.10) between the 3 readers.

CONCLUSIONS

The recommendation of MRI to further evaluate STM lesions seen with US frequently fails to change the working diagnosis or provide significant diagnostic utility.

Artificial Intelligence for Classification of Soft-Tissue Masses at US

Purpose

To train convolutional neural network (CNN) models to classify benign and malignant soft-tissue masses at US and to differentiate three commonly observed benign masses.

Materials and Methods

In this retrospective study, US images obtained between May 2010 and June 2019 from 419 patients (mean age, 52 years ± 18 [standard deviation]; 250 women) with histologic diagnosis confirmed at biopsy or surgical excision (n = 227) or masses that demonstrated imaging characteristics of lipoma, benign peripheral nerve sheath tumor, and vascular malformation (n = 192) were included. Images in patients with a histologic diagnosis (n = 227) were used to train and evaluate a CNN model to distinguish malignant and benign lesions. Twenty percent of cases were withheld as a test dataset, and the remaining cases were used to train the model with a 75%-25% training-validation split and fourfold cross-validation. Performance of the model was compared with retrospective interpretation of the same dataset by two experienced musculoskeletal radiologists, blinded to clinical history. A second group of US images from 275 of the 419 patients containing the three common benign masses was used to train and evaluate a separate model to differentiate between the masses. The models were trained on the Keras machine learning platform (version 2.3.1), with a modified pretrained VGG16 network. Performance metrics of the model and of the radiologists were compared by using the McNemar test, and 95% CIs for performance metrics were estimated by using the Clopper-Pearson method (accuracy, recall, specificity, and precision) and the DeLong method (area under the receiver operating characteristic curve).

Results

The model trained to classify malignant and benign masses demonstrated an accuracy of 79% (95% CI: 68, 88) on the test data, with an area under the receiver operating characteristic curve of 0.91 (95% CI: 0.84, 0.98), matching the performance of two expert readers. Performance of the model distinguishing three benign masses was lower, with an accuracy of 71% (95% CI: 61, 80) on the test data.

Conclusion

The trained CNN was capable of differentiating between benign and malignant soft-tissue masses depicted on US images, with performance matching that of two experienced musculoskeletal radiologists.© RSNA, 2020.

Supraspinatus muscle shear wave elastography (SWE): detection of biomechanical differences with varying tendon quality prior to gray-scale morphologic changes

OBJECTIVE

The purpose of this study was to determine whether SWE can detect biomechanical changes in the supraspinatus muscle that occur with increasing supraspinatus tendon abnormality prior to morphologic gray-scale changes.

MATERIALS AND METHODS

An IRB approved, HIPAA compliant retrospective study of shoulder ultrasounds from 2013-2018 was performed. The cohort consisted of 88 patients (mean age 55 ± 15 years old) with 110 ultrasounds. Images were acquired in longitudinal orientation to the supraspinatus muscle with shear wave velocity (SWV) point quantification. The tendon and muscle were graded in order of increasing tendinosis/tear (1-4 scale) and increasing fatty infiltration (0-3 scale). Mixed model analysis of variance, analysis of covariance, and Spearman rank correlation were used for statistical analysis.

RESULTS

There was no statistically significant age or sex dependence for supraspinatus muscle SWV (p = 0.314, 0.118, respectively). There was no significant correlation between muscle SWV and muscle or tendon grade (p = 0.317, 0.691, respectively). In patients with morphologically normal muscle on gray-scale ultrasound, there were significant differences in muscle SWV when comparing tendon grade 3 with grades 1, 2, and 4 (p = 0.018, 0.025, 0.014, respectively), even when adjusting for gender and age (p = 0.044, 0.028, 0.018, respectively). Pairwise comparison of tendon grades other than those mentioned did not achieve statistical significance (p > 0.05).

CONCLUSION

SWE can detect biomechanical differences within the supraspinatus muscle that are not morphologically evident on gray-scale ultrasound. Specifically, supraspinatus tendon partial tears with moderate to severe tendinosis may correspond to biomechanically distinct muscle properties compared to both lower grades of tendon abnormality and full-thickness tears.

Accuracy of Ultrasound-Guided versus Landmark-Guided Intra-articular Injection for Rat Knee Joints

Our aim was to test the effectiveness of ultrasound-guided intra-articular (IA) injection into the knee joint of rodents by an inexperienced operator compared with standard landmark-guided IA injections by a trained injector. Fifty landmark-guided and 46 ultrasound-guided IA injections in 49 rats were analyzed. Animal positioning and injection protocol were designed for use with the ultrasound system. Injection delivery was verified with a secondary imaging modality. We compared the success of IA injections by method (landmark and ultrasound-guided), adjusting for all other confounding factors (age, weight, experience, laterality and presence of surgery). Ultrasound-guided injections had higher success rates overall (89% vs. 58%) and helped to reduce the number of failed attempts per injection. None of the cofounding factors influenced the success of injection. In conclusion, we found higher accuracy for ultrasound-guided IA injection delivery than the traditional landmark-based injection method and also the technical feasibility for untrained personnel.

Ultrasound-Guided Therapeutic Scapulothoracic Interval Injections

Scapulothoracic pain is a common ailment, but the underlying cause can be difficult to diagnose in a timely manner, and treatment options are limited. We retrospectively review our experience using ultrasound-guided therapeutic scapulothoracic interval steroid injections to treat scapulothoracic pain and review correlative magnetic resonance imaging findings over a 5-year period. Although a variety of structural causes are known to cause scapulothoracic pain, in our experience, most cases lack correlative imaging findings. Ultrasound-guided scapulothoracic interval injections provide a safe, easily performed diagnostic and therapeutic tool for treating patients with periscapular pain, providing at least short-term symptom relief.

ACR Appropriateness Criteria® Shoulder Pain-Atraumatic

Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. 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.

Can Elite Dancers Return to Dance After Ultrasound-Guided Platelet-Rich Plasma (PRP) Injections?

Dancers exert tremendous stresses on the lower extremities rendering them prone to injuries that can curtail training and performance. The goal of this study was to evaluate clinical improvement in a population of elite dancers following treatment with ultrasound-guided platelet-rich plasma (PRP) injections of various lower extremity sites by assessing when they were able to return to dance. Nineteen dancers (13 female, 6 male; ages 15 to 42) were treated between 2009 and 2016 at sites that included: hamstring tendon (1), proximal iliotibial band (1), patellar tendon (3), posterior tibial tendon (5), peroneus brevis tendon (3), plantar fascia (3), and the first metatarsophalangeal (MTP) joint capsule (3). Injections were performed by a single radiologist using the same PRP kit under ultrasound guidance. All patients adhered to standard post-care instructions, including non-weightbearing and avoidance of NSAIDs for at least 2 weeks post-injection. Clinical charts were reviewed for factors including: adherence to post-injection immobilization and physical therapy, physical exam assessments, and milestones in returning to dance. The time-point for returning to dance was defined by attendance of class or rehearsal without symptoms referring to the treated site. Eighteen subjects achieved return to dance, 13 in 6 months or less, and the majority (10) within 3 months of injection. Five subjects required more than 6 months recovery time. These cases all involved foot and ankle sites; of these, two subjects required repeat injections, and both returned to dance within 11 months of the second injection. In the single case where PRP treatment failed, the injury treated was severe plantar fasciopathy with a high-grade central cord tear. It is concluded that ultrasound-guided PRP injections may play a role in the treatment of various lower extremity injuries in elite dancers, with the majority of subjects in this series returning to dance within 6 months. Recovery time may vary depending on the site treated and severity of the presenting injury.

Use of a Simple, Inexpensive Dual-Modality Phantom as a Learning Tool for Magnetic Resonance Imaging-Ultrasound Fusion Techniques

We describe an easily constructed, customizable phantom for magnetic resonance imaging-ultrasound fusion imaging and demonstrate its role as a learning tool to initiate clinical use of this emerging modality. Magnetic resonance imaging-ultrasound fusion can prove unwieldy to integrate into routine practice. We demonstrate real-time fusion with single-sequence magnetic resonance imaging uploaded to the ultrasound console. Phantom training sessions allow radiologists and sonographers to practice fiducial marker selection and improve efficiency with the fusion hardware and software interfaces. Such a tool is useful when the modality is first introduced to a practice and in settings of sporadic use, in which intermittent training may be useful.

Shear wave elastography in the pronator quadratus muscle following distal radial fracture fixation: A feasibility study comparing the operated versus nonoperated sides

The aim of this study was to assess changes in shear wave velocity within the pronator quadratus muscle in patients following volar plate fixation for distal radial fractures compared to the contralateral nonoperated side. Shear wave velocity values were obtained in the short and long axis of the pronator quadratus muscle, which were analyzed separately. Patients were also stratified by age below or above 66 years. Statistical analysis was performed using paired sample Wilcoxon signed rank and t tests. Pearson and Spearman rank correlations were also used. Seventeen patients (nine women and eigth men; age range 33-82, mean 62.4 years) were prospectively assessed following open reduction volar plate fixation of distal radial fracture. A statistically significant reduction in the velocities of the treated versus the nontreated side was observed in the long axis of the muscle (3.29 versus 3.59 m/second; t test p = 0.035). The data provide evidence for shear wave elastography as a quantitative measure to assess postoperative changes in muscle and a potential tool to monitor the efficacy of rehabilitation.

Ultrasound-guided therapeutic injections for neural pathology about the foot and ankle: a 4 year retrospective review

OBJECTIVE

To describe a 4-year clinical experience with ultrasound-guided therapeutic perineural injections of peripheral nerves about the foot and ankle.

MATERIALS AND METHODS

Retrospective analysis of foot and ankle perineural injections performed between January 2012 and August 2016. Demographics, clinical indications, presence of structural pathology, immediate and interval pain relief, as well as complications were recorded.

RESULTS

Fifty-nine therapeutic injections were performed among 46 patients, accounting for multiple injections in a single visit or multiple visits [mean age = 43 years (range 18-75), 31 female (67%) and 15 male (33%)]. Most commonly, perineural injections involved the hallux branch of the medial plantar nerve (n = 17, 22%). Least commonly, perineural injections involved the saphenous nerve (n = 3, 4%). Other injections in our series include sural (10), superficial (11) and deep (7) peroneal, medial (5) and lateral (3) plantar nerves, and the posterior tibial nerve (3). Ultrasound evaluation revealed structural abnormality associated with the nerve in 30 cases (51%)-most commonly thickening with perineural scarring (n = 14). Of 45 injections with complete documentation, immediate relief of symptoms was reported in 43 (96%) cases. Interval symptom relief was achieved in 23 injections [short term (n = 12), intermediate (n = 6), and long term (n = 5)] out of 38 for which follow-up was available (61%). Complications are rare, occurring in only one case.

CONCLUSION

Ultrasound-guided perineural injections about the foot and ankle are safe and provide lasting symptomatic relief for many indications. Concomitant sonographic evaluation identifies structural abnormalities that may contribute to neuropathic symptoms, allowing targeting of injection or clinical therapy.

Tibial Nerve Block Using an Ultrasound-Guided Inframalleolar Medial Plantar Nerve Perineural Injection: A Technical Note

Sonographic-guided tibial nerve block allows for rapid anesthetization of the heel and plantar regions of the foot. We describe a variant technique for tibial nerve regional anesthesia utilizing perineural injection of the medial plantar nerve proximal to the sustentaculum tali where the nerve is superficial and readily accessed, with resultant retrograde flow of local anesthetic proximally. Perineural injection of the medial plantar nerve at the inframalleolar level provides a simple, safe, and effective alternative method to achieve tibial nerve block for regional anesthesia in a variety of procedures. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:134-137, 2017.

Quantitative assessment of the supraspinatus tendon on MRI using T2/T2* mapping and shear-wave ultrasound elastography: a pilot study

OBJECTIVE

To determine whether there is an association between T2/T2* mapping and supraspinatus tendon mechanical properties as assessed by shear-wave ultrasound elastography (SWE).

MATERIALS AND METHODS

This HIPAA-compliant prospective pilot study received approval from our hospital's institutional review board. Eight patients (3 males/5 females; age range 44-72 years) and nine shoulders underwent conventional shoulder MRI, T2/T2* mapping on a 3-T scanner, and SWE. Two musculoskeletal radiologists reviewed the MRI examinations in consensus for evidence of supraspinatus tendon pathology, with tear size measured for full-thickness tears. T2/T2* values and ultrasound shear-wave velocities (SWV) were calculated in three corresponding equidistant regions of interest (ROIs) within the insertional 1-2 cm of the supraspinatus tendon (medial, middle, lateral). Pearson correlation coefficients between T2/T2* values and SWV, as well as among T2, T2*, SWV and tear size, were calculated.

RESULTS

There was a significant negative correlation between T2* and SWV in the lateral ROI (r = -0.86, p = 0.013) and overall mean ROI (r = -0.90, p = 0.006). There was significant positive correlation between T2 and measures of tear size in the lateral and mean ROIs (r range 0.71-0.77, p range 0.016-0.034). There was significant negative correlation between SWV and tear size in the middle and mean ROIs (r range -0.79--0.68, p range 0.011-0.046).

CONCLUSION

Our pilot study demonstrated a potential relationship between T2* values and shear wave velocity values in the supraspinatus tendon, a finding that could lead to an improved, more quantitative evaluation of the rotator cuff tendons.

Shear Wave Ultrasound Elastographic Evaluation of the Rotator Cuff Tendon

OBJECTIVES

(1) Assess the association between the B-mode morphologic appearance and elasticity in the rotator cuff tendon using shear wave elastography (SWE). (2) Assess the association between SWE and symptoms.

METHODS

Institutional Review Board approval and informed consent were obtained. A retrospective review identified 21 studies in 19 eligible patients for whom SWE was performed during routine sonographic evaluations for shoulder pain. Evaluations were compared with 55 studies from 16 asymptomatic volunteers and 6 patients with asymptomatic contralateral shoulders. Repeated studies were accounted for by resampling. Proximal and distal tendon morphologic characteristics were graded from 1 to 4 (normal to full-thickness tear), and average shear wave velocity (SWV) measurements were obtained at both locations. In 68 examinations, deltoid muscle SWV measurements were available for post hoc analysis.

RESULTS

The morphologic grade and SWV showed weak-to-moderate negative correlations in the proximal (P < .001) and distal (P = .002) rotator cuff tendon. A weakly significant SWV decrease was found in the proximal tendon in symptomatic patients (P = .049); no significant difference was seen in the distal tendon. The deltoid muscle SWV showed weak-to-moderate negative correlations with the morphologic grade in the proximal (P = .004) and distal (P = .007) tendon; the deltoid SWV was also significantly lower in symptomatic shoulders (P = .001).

CONCLUSIONS

Shear wave elastography shows tendon softening in rotator cuff disease. It captures information not obtained by a morphologic evaluation alone; however, a poor correlation with symptoms suggests that SWE will be less useful in workups for shoulder pain than for preoperative assessments of tendon quality. Deltoid muscle softening seen in morphologically abnormal and symptomatic patients requires further exploration.

Clinical and Ultrasonographic Evaluations of the Shoulders of Elite Swimmers

BACKGROUND

Shoulder pain is a common problem in competitive swimmers, but the structural alterations in elite-level competitive swimmers are not well known.

HYPOTHESIS

Adaptive changes are common in the rotator cuff, bursa, labrum, and capsule in elite swimmers, and such abnormalities are related to factors concerning training and correlate with symptoms.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The study population was the 2008 United States Olympic swimming team. All athletes completed standardized scales on shoulder pain and function and provided data on their training history and history of shoulder pain or injuries. Each athlete also underwent a comprehensive physical examination of both shoulders, followed by an evaluation of the rotator cuff, biceps, and bursa using ultrasound with dynamic images to assess for subcoracoid impingement and subacromial impingement.

RESULTS

A history of shoulder pain was reported by 29 of 42 (66%) athletes. Morphological changes consistent with tendinosis were common in the biceps (33/46 shoulders; 72%) and supraspinatus/infraspinatus (44/46 shoulders; 96%). Subcoracoid impingement was seen in 17 of 46 shoulders (37%), with subacromial impingement seen in 34 of 41 shoulders (83%). There was an increased odds ratio (OR) for biceps tendinosis in older swimmers (OR, 1.92; 95% CI, 1.23-3.00; P = .004) and in swimmers who had missed a competition because of shoulder pain (OR, 9.76; 95% CI, 1.13-84.3; P = .038). There was an increased OR for rotator cuff tendinosis in swimmers who reported worse scores for pain with activities (OR, 0.10; 95% CI, 0.01-0.78; P = .028) and in those with a positive sulcus sign (OR, 33.2; 95% CI, 3.09-355; P = .004). There was an increased OR for impingement in swimmers with a positive sulcus sign (OR, 5.40; 95% CI, 0.80-36.3; P = .083), worse pain scores (OR, 0.44; 95% CI, 0.22-0.87; P = .019), and a partial rotator cuff tear (OR, 31.2; 95% CI, 3.58-272; P = .002).

CONCLUSION

We found a high prevalence of rotator cuff and biceps tendinopathy, which was associated with increased symptoms. Tendinosis was also more common in swimmers with a positive sulcus sign, suggesting a role for shoulder laxity.

ACR Appropriateness Criteria Follow-Up of Malignant or Aggressive Musculoskeletal Tumors

Appropriate imaging modalities for the follow-up of malignant or aggressive musculoskeletal tumors include radiography, MRI, CT, (18)F-2-fluoro-2-deoxy-D-glucose PET/CT, (99m)Tc bone scan, and ultrasound. Clinical scenarios reviewed include evaluation for metastatic disease to the lung in low- and high-risk patients, for osseous metastatic disease in asymptomatic and symptomatic patients, for local recurrence of osseous tumors with and without significant hardware present, and for local recurrence of soft tissue tumors. The timing for follow-up of pulmonary metastasis surveillance is also reviewed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Ultrasound-Guided Biceps Peritendinous Injections in the Absence of a Distended Tendon Sheath: A Novel Rotator Interval Approach

This retrospective study evaluated the technical success rate of a novel injection into the long head of the biceps tendon sheath by a rotator interval approach in 26 patients. A 25-gauge, 1.5-in needle was positioned into the rotator interval from a lateral approach, where a therapeutic injection was performed. Postinjection sonograms images were reviewed to assess for fluid within the sheath to calculate the technical success rate. Fluid distention of the biceps tendon sheath was shown in all 26 cases, corresponding to a 100% technical success rate. In addition, postinjection ultrasound imaging of the anterior shoulder provided additional diagnostic findings in 6 of 26 patients (23%).

Skeletal Muscle in Healthy Subjects versus Those with GNE-Related Myopathy: Evaluation with Shear-Wave US--A Pilot Study

PURPOSE

To determine whether quantitative differences in shear-wave velocity (SWV) exist between normal skeletal muscle and those affected by GNE-related myopathy and to examine the effects of muscle anisotropy, depth, and axial preload on SWV in a healthy control group.

MATERIALS AND METHODS

This study was approved by the institutional review board and compliant with HIPAA. Informed consent was obtained from all study volunteers. Eight patients (four women and four men aged 30-50 years) with genetically and biopsy-proved GNE-related myopathy and five healthy volunteers (three women and two men aged 27-33 years) underwent SWV imaging with use of a 9-MHz linear transducer. The gastrocnemius muscles were evaluated in the patients with GNE-related myopathy, and the gastrocnemius, vastus lateralis, and rectus femoris muscles were evaluated in the healthy cohort. The effect of muscle anisotropy, axial preload, and sample volume depth were examined in the healthy cohort. The effect of anisotropy at a fixed depth and preload were examined in the patients with GNE-related myopathy.

RESULTS

Irrespective of the muscle, the mean SWV was significantly higher with the transverse orientation than with the longitudinal orientation (P < .001). In the healthy cohort, the mean SWV for superficial measurements was significantly lower than that for deep measurements (P < .02). The mean SWV with preload was significantly higher with compression (P < .001) for the rectus femoris only. The mean SWV was significantly lower in patients with GNE-related myopathy than in control subjects (P < .02).

CONCLUSION

SWV parametric imaging may provide a useful quantitative adjunct in the assessment of disease activity in patients with GNE-related myopathy. There is diminished SWV and muscle anisotropy in GNE-related myopathy.

Ultrasound diagnosis and evaluation of plantar heel pain

BACKGROUND

One of the most common causes of heel pain is plantar fasciitis; however, there are other pathologic disorders that can mimic the symptoms and clinical presentation of this disorder. The purpose of this study was to retrospectively review the prevalence of various pathologic disorders on ultrasound in patients with proximal plantar heel pain.

METHODS

The medical records and diagnostic ultrasound reports of patients presenting with plantar heel pain between March 1, 2006, and March 31, 2007, were reviewed retrospectively, and the prevalence of various etiologies was collected. The inclusion criteria were based on their clinical presentation of plantar fasciitis or previous diagnosis of plantar fasciitis from an unknown source. Ultrasound evaluation was then performed to confirm the clinical diagnosis.

RESULTS

We examined 175 feet of 143 patients (62 males and 81 females; age range, 16-79 years). Plantar fibromas were present in 90 feet (51%). Plantar fasciitis was diagnosed in 128 feet (73%). Coexistent plantar fibroma and plantar fascial thickening was found in 63 feet (36%). Of the 47 feet that were negative for plantar fasciitis on ultrasound, 27 (57%) revealed the presence of plantar fibroma.

CONCLUSIONS

Diagnostic ultrasound can effectively and safely identify the prevalence of various etiologies of heel pain. The high prevalence of plantar fibromas and plantar fascial tears cannot be determined by clinical examination alone, and, therefore, ultrasound evaluation should be performed for confirmation of diagnosis.

Postoperative rotator cuff

This article provides a brief overview of the current state of ultrasound (US) imaging of rotator cuff repairs with emphasis on current morphological assessment and development of newer techniques in which US may play an important role in assessing healing response. Emphasis is on the supraspinatus tendon inasmuch as it is the most commonly affected tendon in rotator cuff disease. Assessment of the tendon repair following joint replacement is also commented on in which the standard anterior approach may be associated with dehiscence of the subscapularis tendon.

Platelet-rich plasma for the treatment of lateral epicondylitis: sonographic assessment of tendon morphology and vascularity (pilot study)

OBJECTIVE

To investigate the efficacy of using contrast-enhanced ultrasound to assess the relationship of altered vascularity and tendon morphology following injection of platelet-rich plasma (PRP) for lateral epicondylitis.

MATERIALS AND METHODS

This study prospectively evaluated six patients who had a baseline ultrasound confirming tendinosis of the common extensor tendon. Patients received a single 3-ml PRP injection under ultrasound guidance. Grayscale images of the injected elbow were obtained at baseline and were repeated at 1 and 6 months after injection. DEFINITY® contrast was also injected after by 2 sets of wrist-extension exercises in order to obtain contrast-enhanced images of the elbow. Qualitative and quantitative analyses of the level of enhancement to the regions of interest were performed using off-line quantitative analysis software.

RESULTS

All patients had either moderate or severe common extensor tendinosis as determined on clinical examination and baseline imaging. Five patients demonstrated improved tendon morphology using ultrasound imaging 6 months after PRP injection (one patient was lost to follow-up). At baseline, there was evidence of increased vascularity at the myotendinous junction (MT) of the common extensor tendon when compared to its footprint (FP). There was a trend towards no change in FP vascularity between baseline and 6 months (p = 0.062) and between 1 and 6 months (p = 0.288). There was a trend for increased vascularity to the MT region from baseline to 6 months (p = 0.433) and from 1 to 6 months (p = 0.783).

CONCLUSIONS

Contrast-enhanced ultrasound provides a sensitive method the display alterations in vascularity in the common extensor tendon of the elbow. PRP therapy for lateral epicondylitis can improve extensor tendon morphology. Corresponding increased extensor tendon FP vascularity, however, was not seen. There is a trend for increased vascularity at the MT up to 6 months following PRP injection, based on limited pilot data.

Sonography of supraspinatus tendon abnormalities in the neutral versus Crass and modified Crass positions: a prospective study

OBJECTIVES

The purpose of this study was to investigate how well the neutral arm position correlates with the Crass and modified Crass positions in sonographic evaluation of supraspinatus tendon abnormalities.

METHODS

A prospective study was performed on 32 shoulders in 31 patients with shoulder pain. Images were acquired in the long axis of the supraspinatus tendon in the neutral, Crass, and modified Crass positions and were reviewed independently of each other by 2 radiologists in consensus. The images were evaluated for visualized tendon length, tendinosis, partial- or full-thickness tears, calcific tendinosis, subdeltoid bursitis, and enthesopathic changes. Kappa values of agreement between neutral and Crass and neutral and modified Crass positions were determined.

RESULTS

The mean visualized tendon lengths were 1.78, 2.83, and 2.77 cm in the neutral, Crass, and modified Crass positions, respectively. Kappa agreements between neutral and Crass and neutral and modified Crass positions were as follows: perfect agreement for calcific tendinosis (neutral versus Crass, κ =1.00; neutral versus modified Crass, κ = 1.00), almost perfect agreement for full-thickness tears (neutral versus Crass, κ = 0.85; neutral versus modified Crass: κ= 0.92) and tendinosis (neutral versus Crass, κ = 0.93; neutral versus modified Crass, κ = 0.86), substantial agreement for enthesopathic changes (neutral versus Crass, κ= 0.80; neutral versus modified Crass, κ= 0.61) and subdeltoid bursitis (neutral versus Crass, κ = 0.63; neutral versus modified Crass, κ = 0.75), and moderate agreement for partial tears (neutral versus Crass, κ = 0.44; neutral versus modified Crass, κ = 0.47).

CONCLUSIONS

For patients who cannot tolerate the Crass or modified Crass position, the neutral position can show full-thickness tears, tendinosis, calcific tendinosis, enthesopathic changes, and bursitis.

The effect of platelet-rich fibrin matrix on rotator cuff tendon healing: a prospective, randomized clinical study

BACKGROUND

There is a strong need for methods to improve the biological potential of rotator cuff tendon healing. Platelet-rich fibrin matrix (PRFM) allows delivery of autologous cytokines to healing tissue, and limited evidence suggests a positive effect of platelet-rich plasma on tendon biology.

PURPOSE

To evaluate the effect of platelet-rich fibrin matrix on rotator cuff tendon healing.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Seventy-nine patients undergoing arthroscopic rotator cuff tendon repair were randomized intraoperatively to either receive PRFM at the tendon-bone interface (n = 40) or standard repair with no PRFM (n = 39). Standardized repair techniques were used for all patients. The postoperative rehabilitation protocol was the same in both groups. The primary outcome was tendon healing evaluated by ultrasound (intact vs defect at repair site) at 6 and 12 weeks. Power Doppler ultrasound was also used to evaluate vascularity in the peribursal, peritendinous, and musculotendinous and insertion site areas of the tendon and bone anchor site. Secondary outcomes included standardized shoulder outcome scales (American Shoulder and Elbow Surgeons [ASES] and L'Insalata) and strength measurements using a handheld dynamometer. Patients and the evaluator were blinded to treatment group. All patients were evaluated at minimum 1-year follow-up. A logistic regression model was used to predict outcome (healed vs defect) based on tear severity, repair type, treatment type (PRFM or control), and platelet count.

RESULTS

Overall, there were no differences in tendon-to-bone healing between the PRFM and control groups. Complete tendon-to-bone healing (intact repair) was found in 24 of 36 (67%) in the PRFM group and 25 of 31 (81%) in the control group (P = .20). There were no significant differences in healing by ultrasound between 6 and 12 weeks. There were gradual increases in ASES and L'Insalata scores over time in both groups, but there were no differences in scores between the groups. We also found no difference in vascularity in the peribursal, peritendinous, and musculotendinous areas of the tendon between groups. There were no differences in strength between groups. Platelet count had no effect on healing. Logistic regression analysis demonstrated that PRFM was a significant predictor (P = .037) for a tendon defect at 12 weeks, with an odds ratio of 5.8.

CONCLUSION

Platelet-rich fibrin matrix applied to the tendon-bone interface at the time of rotator cuff repair had no demonstrable effect on tendon healing, tendon vascularity, manual muscle strength, or clinical rating scales. In fact, the regression analysis suggests that PRFM may have a negative effect on healing. Further study is required to evaluate the role of PRFM in rotator cuff repair.

Contrast-enhanced ultrasound characterization of the vascularity of the repaired rotator cuff tendon: short-term and intermediate-term follow-up

BACKGROUND

The objectives of this study were to characterize and compare the vascularity of arthroscopically repaired rotator cuff tendons at short-term and intermediate-term follow-up.

MATERIALS AND METHODS

Nineteen patients who underwent arthroscopic rotator cuff repair were prospectively monitored for an average of 21.2 months. Initial baseline, grayscale ultrasound images of the operated-on shoulder were obtained on all patients at 3 months and at a minimum of 10 months postoperatively. Perflutren-lipid microsphere contrast (DEFINITY, Lantheus Medical Imaging, North Billerica, MA, USA) was injected after baseline grayscale images and after exercise to obtain contrast-enhanced images of the repair. Three regions of interest--supraspinatus tendon, peribursal tissue, and bone anchor site--were evaluated before and after rotator cuff-specific exercises.

RESULTS

The peribursal tissue demonstrated the greatest blood flow, followed by the bone anchor site and tendon, in pre-exercise and postexercise states. Significantly less blood flow was observed in all regions of interest before exercise (P < .05) and only at the bone anchor site after exercise (P < .001) at latest follow-up compared with the 3-month values. Intratendinous blood flow remained relatively low at both evaluation points after surgical repair.

CONCLUSION

Preliminary findings suggest that the peribursal tissue and bone anchor site are the main conduits of blood flow for the rotator cuff tendon after arthroscopic repair, with the supraspinatus tendon being relatively avascular. Blood flow of the repaired rotator cuff tendon decreases with time. Furthermore, exercise significantly enhances blood flow to the repaired rotator cuff.

Comparative analysis of 2- versus 3-dimensional sonography of the supraspinatus tendon

OBJECTIVES

The purpose of this study was to determine the reliability in the analysis of images acquired using a dedicated 3-dimensional (3D) ultrasound transducer and conventional 2-dimensional (2D) images in the detection and characterization of supraspinatus tendon tears.

METHODS

Images of the supraspinatus tendon in 42 patients who had undergone 2D and 3D sonography were classified by two readers independently as no tear, full-thickness tear, or partial-thickness tear. When present, the tear size and location were recorded. Inter- and intra-rater reliability for the two data sets were calculated.

RESULTS

There was substantial agreement between the two readers in the classification of supraspinatus tendon tears on 2D images (κ = 0.79) but only moderate agreement on 3D images (κ = 0.48). There was moderate to substantial agreement in the classification of tears between the 2D and 3D images for both readers (reader 1, κ = 0.64; reader 2, κ= 0.54). The most common cause of a discordant result was the interpretation of a small hypoechoic region at the footprint as a partial tear on 3D images, compared to a normal appearance on 2D images.

CONCLUSIONS

Use of a dedicated 3D ultrasound transducer has poorer inter- and intra-rater reliability for the assessment of supraspinatus tendon tears compared to 2D sonography because of the interpretation of small partial-thickness tears at the footprint on 3D images, a common region affected by anisotropy.

Technique for margin convergence in rotator cuff repair

The purpose of the present study is to describe the technique of margin convergence for U-shaped rotator cuff tears and report the clinical outcomes and ultrasonography with a minimum of 2 years follow-up. Three hundred eleven patients with a rotator cuff tear were prospectively enrolled in a registry at one institution. Inclusion criteria included any patient undergoing arthroscopic margin convergence for a rotator cuff tear. Exclusion criteria included open or mini-open rotator cuff repairs or suture anchor fixation to the cuff insertion without margin convergence. The outcome measurements included physical examination, manual muscle testing, the American Shoulder and Elbow Surgeons (ASES) score, and ultrasonography. Nineteen patients met the study criteria and 13 were available for 2-year follow-up (68.4%). The mean age of this cohort was 62.2 ± 7.5 years with a mean pre-operative rotator cuff tear size of 4.0 ± 1.6 cm. The ASES score increased significantly from 50.0 ± 17.7 before surgery to 83.3 ± 19.5 at 2 years (P = 0.01). The active forward elevation also improved from 156.2 ± 11.9° before surgery to 168.0 ± 12.1 at 2 years (P = 0.03). The active external rotation 54.4 ± 14.5 at baseline and improved to 57.1 ± 19.1 at 2 years (P = 0.04). The strength also increased significantly from 6.7 ± 6.4 to 10.6 ± 4.9 lb at 1 year (P = 0.048). The post-operative ultrasound demonstrated that 46.2% of rotator cuff tears were healed at 2 years. In conclusion, margin convergence is a useful technique for U-shaped tears that are difficult to mobilize.

Prospective evaluation of arthroscopic rotator cuff repairs at 5 years: part I--functional outcomes and radiographic healing rates

BACKGROUND

A rotator cuff registry was established to prospectively evaluate the effectiveness of all-arthroscopic repairs. This study reports those results at 5 years.

MATERIALS AND METHODS

The study enrolled 193 patients who underwent all-arthroscopic rotator cuff repairs. Patients were evaluated preoperatively and at 1, 2, and 5 years postoperatively. Outcome measurements included the American Shoulder and Elbow Surgeons (ASES) score, range of motion, manual muscle testing, and ultrasonography.

RESULTS

At 5-years, 106 patients completed follow-up, representing 55% of the patients originally enrolled but 77% of those who returned for evaluation at 1 year. ASES scores improved from 52.6 ± 23.2 preoperatively to 92.6 ± 14.8 at 5 years (P < .001). Paired analyses showed no differences between the ASES scores at 2 and 5 years, but the scores improved from 1 to 5 years (P = .002). Between years 2 and 5, passive forward elevation decreased from 173° ± 10.3° to 168.6° ± 16.8° (P = .02) and external rotation decreased from 73.6° ± 21.3° to 67.8° ± 19.6° (P = .04). Patients improved a full motor grade in forward elevation and external rotation and this remained stable over time. The healing rates for all patients were 64.3% at 1 year, 75.4% at 2 years, and 81.2% at 5 years. Paired analyses showed increased healing rates from 1 to 5 years (P = .001) and from 2 to 5 years (P = .05).

DISCUSSION

The midrange results of all-arthroscopic rotator cuff repairs are good, and functional results remain constant over 5 years. The ultrasound healing rates continued to increase with time; however, the mechanism and the clinical significance of this are uncertain at this time.

Prospective evaluation of arthroscopic rotator cuff repairs at 5 years: part II--prognostic factors for clinical and radiographic outcomes

BACKGROUND

A rotator cuff registry was established to prospectively evaluate the effectiveness of all-arthroscopic repairs. The purpose of this study is to report prognostic factors for successful clinical and radiographic outcomes at 5 years.

METHODS

One-hundred ninety-three patients underwent all-arthroscopic rotator cuff repairs. Pre- and intraoperative data were compared to the American Shoulder and Elbow Surgeon (ASES) score, range of motion, muscle strength, and ultrasound results at 5 years using univariate, and multivariate analyses.

RESULTS

At 5 years, 106 patients completed follow-up. There were no pre- or intraoperative variables that were predictive of an ASES score >90. Factors predictive of a radiographic defect were larger size of the lesion (OR 1.72, 95% CI 1.04-2.85, P = .03), multiple tendon involvement (OR 5.56, 95% CI 1.23-25.22, P = .02), older age (OR 1.15, 95% CI 1.04-1.28, P = .01), concomitant biceps (OR 16.16, 95% CI 3.01-86.65, P = .001), and acromioclavicular joint procedures (OR 6.70, 95% CI 1.46-30.73, P = .01). Radiographic healing did not correspond to clinical outcomes. Resolution of a radiographic defect was seen in 14 patients. Younger age (OR 0.84, 95% CI 0.74-0.95, P = .004) and single-tendon tears (OR 7.59, 95% CI 1.71-84.45, P = .04) were predictive.

DISCUSSION

Larger tears in older patients who undergo concomitant procedures are predictive of radiographic defects at 5 years; however, radiographic healing did not correspond to clinical results. Younger patients with single tendon tears are more likely to undergo spontaneous resolution of a radiographic defect. This information can be useful in counseling patients regarding the mid-term results of this procedure.

Contrast-enhanced sonographic characterization of the vascularity of the repaired rotator cuff: utility of maximum intensity projection imaging

OBJECTIVES

To characterize the distribution of vascularity of the postoperative rotator cuff tendon using a maximum intensity projection technique after contrast-enhanced sonography.

METHODS

We retrospectively evaluated image data on 23 patients (11 male and 12 female) with intact rotator cuff repairs who had previously undergone contrast-enhanced sonography of their shoulders using lipid microspheres before and after a standardized exercise protocol. The patients were on average 3 months out from their surgery. Using offline image analysis software, a maximum intensity projection image was obtained for each patient, reflecting the regional vascular distribution within the repair and adjacent soft tissue. Subjective analysis was performed in 4 regions of interest: peribursal, articular medial, articular lateral, and suture anchor, independently by 2 musculoskeletal radiologists using a semiquantitative scale ranging from 0 to 4 for each region (0, no enhancement; 1, 1%-25% enhancement; 2, 26%-50%; 3, 51%-75%; and 4, 76%-100%). A combined vascularity score (0-8) was produced for each region and formed the basis for the subjective analysis.

RESULTS

Using a Mann-Whitney nonparametric test, the data showed significantly higher regional enhancement in the peribursal and suture anchor regions compared to the tendon (P < .001). Exercise resulted in a statistically significant increase in the extent of enhancement in all regions (P < .002). Inter-rater reliability analysis using a weighted κ statistic showed strong agreement (0.63-0.64) for the suture anchor site and moderate agreement for the others (peribursal, 0.35-0.39; articular medial, 0.45-0.55; and articular lateral 0.32-0.33).

CONCLUSIONS

The maximum intensity projection technique after contrast-enhanced sonography provides a topographic map of rotator cuff vascularity; the latter has been implicated as an important factor in promoting bone-tendon healing. Approximately 3 months after rotator cuff repair, the suture anchor and peribursal regions showed the most robust vascularity. Maximum intensity projection imaging further establishes that there is a global increase in vascular response at the repair site after exercise.

Sonographic evaluation of femoral trochlear cartilage in patients with knee pain

OBJECTIVES

The purpose of this study was to investigate whether routine clinical sonographic evaluation of femoral trochlear cartilage can identify abnormalities in patients with knee pain.

METHODS

Short-axis sonograms of the femoral trochlear cartilage were obtained from 20 symptomatic knees in 20 consecutive patients (16 women and 4 men; mean age, 54 years; range, 35-75 years) and 20 knees in 10 asymptomatic control participants (7 women and 3 men; mean age, 52 years; range, 31-74 years). Articular cartilage thickness was measured at 3 locations in each knee, and thickness at each site was compared between patients and controls. Subsequently, images from patients and controls were randomly assorted and evaluated by 3 blinded musculoskeletal radiologists, who independently evaluated the femoral trochlear cartilage in each sonogram for cartilage clarity, grade, and presence or absence of cartilage calcifications, osteophytes, and subchondral bony irregularity. The radiologists were instructed to rate the most severe lesion in each evaluated region (medial trochlea, trochlear notch, and lateral trochlea). Cartilage clarity was defined as how well the cartilage borders could be distinguished from the overlying intra-articular soft tissues, and grade was defined as the severity of focal cartilaginous lesions.

RESULTS

Using the Student t test, there was no significant difference (P > .05) between cartilage thickness in patients and controls for any location measured. However, using repeated measures analysis of variance, there were significant differences (P = .02) for both decreased cartilage clarity (df = 1/28; F = 5.76) and increased grade (df = 1/28; F = 5.77) in patients. There was also a nonsignificant (P > .05) trend toward more frequent calcifications, osteophytes, and bony irregularity in patients.

CONCLUSIONS

Routine clinical sonography can identify femoral trochlear cartilage abnormalities in patients with knee pain and therefore can be a useful adjunct to other imaging tests for identifying arthritic changes in the knee.

Thromboembolic Complications Following Spine Surgery Assessed with Spiral CT Scans: DVT/PE Following Spine Surgery

Spine surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). The goal of this study was to determine which symptoms and risk factors were associated with spiral CT scans positive for PE and/or DVT in the postoperative spine surgery patient. We conducted a retrospective review of all spine patients who underwent a postoperative CT to rule out PE during the period of March 2004-February 2006. The type of surgical procedure, risk factors, symptoms prompting scan ordering, anticoagulation, and treatment were recorded. Logistic regression models were used to determine significant predictors of a positive CT in this patient population. Of the 3,331 patients that had spine surgery during the study period, 130 (3.9%) had a spiral CT scan to rule out PE and/or proximal DVT. Thirty-three of the 130 (25.4%) CT scans were positive for PE only, five (3.8%) for PE and DVT, and three (2.3%) for DVT only. Only 24.5% (32) patients had risk factors for thromboembolic disease, and of these, a history of PE and/or DVT was the only significant risk factor for a positive scan (p = 0.03). No presenting symptoms or demographic variables were noted to have a significant association with PE and/or DVT. The type of surgical procedure (i.e., anterior, posterior, and percutaneous) was not associated with an increased risk for PE and/or DVT. Patients who are undergoing spine surgery with a history of thromboembolic disease should be carefully monitored postoperatively and may benefit from more aggressive prophylaxis.

Sonographic evaluation and sonographic-guided therapeutic options of lateral ankle pain: peroneal tendon pathology associated with the presence of an os peroneum

Clinical implications of acute injuries of the os peroneum have been described, with the recommendation in some cases being the excision of the bone fragments. We describe the spectrum of sonographic appearances associated with pain in the region of the os peroneum, document associated peroneal tendon pathology, and describe the use of sonography to direct and guide therapeutic and/or diagnostic injections. All sonographic examinations in our ultrasound database from Jan 1, 2001-Jan 30, 2007 with the words "os peroneum" were reviewed. Patients were cross-referenced in our radiology database to find relevant foot or ankle radiographs for correlation. There were 47 patients (18 men and 29 women, age range 16 to 83) referred for sonographic evaluation of lateral foot and/or ankle pain who had an os peroneum identified during the sonographic evaluation. Eighteen patients were referred specifically for targeted injection of the lateral ankle, including peroneal tendon sheath injections (N = 10), calcaneocuboid joint injections (N = 1), and injections around symptomatic os peroneum (N = 7). All 47 patients had tendinosis of the peroneus longus, in varying degrees of severity. Radiographs were available for correlation in 28 patients. The causes of lateral ankle pain with a co-existent os peroneum are multifactorial and may not directly relate to the presence of an os peroneum. Ultrasound can be of value in separating out the specific etiology for pain, as well as provide a method for problem solving by the performance of targeted diagnostic or therapeutic injections in the lateral ankle.

Using magnetic resonance angiography to measure abnormal synovial blood vessels in early inflammatory arthritis: a new imaging biomarker?

OBJECTIVE

To ascertain whether magnetic resonance angiography (MRA) can reliably detect synovial neovascularization in subjects with early inflammatory arthritis.

METHODS

Subjects with 6 weeks to 6 months of clinical evidence of inflammatory hand arthritis had a radiograph, power Doppler ultrasound (PDU) scan, magnetic resonance imaging (MRI), and contrast enhanced MRA performed on the more symptomatic hand. Ultrasound examination of the wrist and 2nd-5th metacarpophalangeal (MCP) joints was scored for erosions, synovial thickening, and synovial blood flow. MRI were assessed using the OMERACT Rheumatoid Arthritis MRI Score (RAMRIS). MRA was used to assess the number of abnormal vessels in the 2nd-5th MCP and in the wrist.

RESULTS

Of 30 subjects, 66.7% showed abnormal vasculature on MRA in the MCP and/or wrist; mean number of abnormal vessels was 5.24 (range 0-22). Number of abnormal vessels on MRA was strongly correlated with degree of blood flow seen in the corresponding area on PDU (r = 0.79, p <or= 0.0001). The number of abnormal vessels was highly correlated with MRI MCP synovitis scores (r = 0.69, p <or= 0.0001), MRI wrist synovitis scores (r = 0.73, p <or= 0.0001), and ultrasound synovitis scores (r = 0.68, p <or= 0.0001).

CONCLUSION

In this cross-sectional pilot study, MRA identified abnormal vessels in patients with early inflammatory arthritis. This is the first report of MRA visualizing abnormal vessels in this patient population. If the degree of neovascularization in early inflammatory arthritis predicts disease course, MRA evidence of abnormal vessels could be a new imaging biomarker.

Detection of Pulmonary Embolism in the Postoperative Orthopedic Patient Using Spiral CT Scans

Orthopedic surgery is associated with a significant risk of postoperative pulmonary embolism (PE) and/or deep vein thrombosis (DVT). This study was performed to compare the clinical presentations of a suspected versus a documented PE/DVT and to determine the actual incidence of PE/DVT in the post-operative orthopedic patient in whom CT was ordered. All 695 patients at our institution who had a postoperative spiral CT to rule out PE/DVT from March 2004 to February 2006 were evaluated and information regarding their surgical procedure, risk factors, presenting symptoms, location of PE/DVT, and anticoagulation were assessed. Statistical analysis was performed using an independent samples t test with a two-tailed p value to examine significant associations between the patient variables and CT scans positive for PE. Logistic regression models were used to determine which variables appeared to be significant predictors of a positive chest CT. Of 32,854 patients admitted for same day surgery across all services, 695 (2.1%) had a postoperative spiral CT based on specific clinical guidelines. The incidence of a positive scan was 27.8% (193/695). Of these, 155 (22.3%) scans were positive for PE only, 24 (3.5%) for PE and DVT, and 14 (2.0%) for DVT only. The most common presenting symptoms were tachycardia (56%, 393/695), low oxygen saturation (48%, 336/695), and shortness of breath (19.6%, 136/695). Symptoms significantly associated with DVT were syncope and chest pain. A past medical history of PE/DVT was the only significant predictor of a positive scan. Patients who have a history of thromboembolic disease should be carefully monitored in the postoperative setting.

Vascularity of the supraspinatus tendon three months after repair: characterization using contrast-enhanced ultrasound

BACKGROUND

There has been limited in-vivo assessment of rotator cuff vascularity following repair. This study aims to characterize the vascularity of the shoulder 3 months following supraspinatus tendon repair.

METHODS

Twenty-nine patients (average age, 61.4 years) underwent Perflutren lipid microsphere contrast-enhanced shoulder ultrasound examinations 3 months after arthroscopic rotator cuff repair. Each shoulder was scanned at rest and following exercise using linear phased array 9-MHz transducer optimized to detect the contrast agent. Blood flow was quantified off-line using ultrasound imaging quantification and analysis software (QLAB, Philips, Andover, MA). Peak enhancement (vascular volume) and rate of rise (perfusion) were determined for 3 regions of interest: peribursal area, supraspinatus tendon, and anchor site.

RESULTS

Peak enhancement and rate of rise were greatest in the peribursal soft tissue and anchor site. Resting peak enhancement and rate of rise were significantly lower within the tendon compared to the other 2 regions (P < .001). Exercise resulted in increased enhancement and rate-of-rise to all 3 regions, but had a significant predilection towards increasing vascular volume within the peri-bursal region (P = .026).

CONCLUSION

At 3 months following repair, the majority of blood flow to the repair is derived from the peribursal soft tissues and the anchor site. The tendon, particularly those with a defect at 3 months, is relatively avascular. Though limited by inclusion of only a single time point, this study introduces a new technique to quantify vascularity following supraspinatus repairs and suggests that the surrounding vascular milieu may play a role in tendon healing.

LEVEL OF EVIDENCE

Basic Science.

The long-term outcome of recurrent defects after rotator cuff repair

BACKGROUND

Retears of the rotator cuff are not uncommon after arthroscopic and mini-open rotator cuff repairs. In most studies, the clinical results in patients with persistent defects demonstrated significantly less pain and better function and strength compared with their preoperative state at an early follow-up.

HYPOTHESIS

The clinical and structural outcomes of patients with known rotator cuff defects will remain unchanged after a longer period of follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study was performed in 15 patients (18 shoulders) from a previous study who had recurrent rotator cuff defects 3.2 years after repair. Each patient completed the American Shoulder and Elbow Surgeons Scoring Survey, the Simple Shoulder Test, the L'Insalata Scoring Survey, and a visual analog scale for pain. Eleven patients (13 shoulders) were clinically reexamined at an average of 7.9 years for range of motion and strength, with targeted ultrasound.

RESULTS

At the 7.9 year follow-up the average scores were 95 (American Shoulder and Elbow Surgeons), 95 (L'Insalata), 11 (Simple Shoulder Test), and 0 (visual analog for pain), which were not statistically significantly different from the scores at 3.2 years. There was no change in the average range of motion; however, there was a statistically significant reduction in forward flexion strength and external rotation strength, as measured by a dynamometer. The average external rotation strength decreased by a mean of 42% and the mean forward flexion strength decreased by a mean of 45% (P < .001). Furthermore, there was a statistically significant increase in the mean size of the defect, from 273 mm(2) to 467 mm(2) (P < .001). Finally, the size of the defect increased in all patients, and no defects healed structurally.

CONCLUSION

At an average of 7.9 years, patients with recurrent defects after rotator cuff repair still had an improvement in terms of pain, function, and satisfaction. However, the rotator cuff defect significantly increased in size, and there was a progression of strength deficits. These findings suggest that patients with recurrent defects can remain asymptomatic over the long term but will predictably lose strength in the involved extremity. Furthermore, the study demonstrated that defects after rotator cuff repair increase in size but often remain asymptomatic.