Musculoskeletal Sonography: A Dynamic Tool for Usual and Unusual Disorders

Asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts

BACKGROUND

The hindfoot region is commonly injured in gymnasts, and musculoskeletal ultrasound can be used to identify structural abnormalities in this region. Although prior studies have shown that sonographic abnormalities may not correlate with symptomatic pathology, the presence of asymptomatic sonographic abnormalities of the hindfoot in Division I collegiate gymnasts has not been evaluated.

OBJECTIVE

To identify and describe commonly seen asymptomatic sonographic abnormalities of the hindfoot region in Division I collegiate gymnasts.

DESIGN

Cross-sectional study.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

39 Division I NCAA men's and women's collegiate gymnasts without current hindfoot pain or history of hindfoot injury.

INTERVENTIONS

Diagnostic musculoskeletal ultrasound of the hindfoot region.

MAIN OUTCOME MEASURES

Sonographic appearance of the hindfoot region, specifically the plantar fascia, plantar fad pad, and Achilles tendon.

RESULTS

A total of 37 of 39 gymnasts included in the study were found to have at least one asymptomatic sonographic abnormality of the hindfoot region. A total of 28.2% of athletes were found to have sonographic abnormalities within the Achilles tendon, with Doppler flow being the most common finding, and 35.8% of athletes were found to have a Haglund's deformity. However, only 7% of athletes with a Haglund's deformity demonstrated abnormal sonographic findings within the tendon. Sonographic abnormalities of the plantar fascia and plantar fat pad were seen in 30.7% and 69.2% of athletes, respectively.

CONCLUSIONS

Asymptomatic sonographic abnormalities of the hindfoot region are common in collegiate gymnasts. Clinicians should use clinical judgment when interpreting these findings as they may not represent symptomatic pathology.

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.

Evaluation of the knee joint with ultrasound and magnetic resonance imaging

The knee joint relies on a combination of deep and superficial structures for stability and function. Both ultrasound and high-resolution magnetic resonance imaging are extremely useful in evaluating these structures and associated pathology. This article reviews a combination of critical anatomic structures, joint abnormalities, and pathologic conditions at the knee joint, while highlighting the merits, limitations, and pitfalls of the two imaging modalities. A clear appreciation of each method paired with its relative strengths will aid in expediting diagnosis and appropriate treatment for a wide range of knee joint conditions.

Advanced Imaging of Ulnar Wrist Pain

Ulnar-sided wrist pain can be a diagnostic challenge for clinicians and radiologists. The ulnar wrist has complex morphology and is composed of many small bone and soft tissue structures. Within these structures, a wide variety of pathologic conditions can occur. To successfully diagnose and treat these pathologic conditions, clinicians and radiologists must have a strong understanding of the advanced imaging techniques available to them. In this review, the authors present a brief review of the normal ulnar wrist anatomy, discuss the differential diagnosis of ulnar-sided wrist pain, and examine the indications for different advanced imaging modalities.

A problem-based approach in musculoskeletal ultrasonography: heel pain in adults

Musculoskeletal ultrasonography (US) has unique advantages, such as excellent spatial resolution for superficial structures, the capability for dynamic imaging, and the ability for direct correlation and provocation of symptoms. For these reasons, US is increasingly used to evaluate problems in small joints, such as the foot and ankle. However, it is almost impossible to evaluate every anatomic structure within a limited time. Therefore, US examinations can be faster and more efficient if radiologists know where to look and image patients with typical symptoms. In this review, common etiologies of heel pain are discussed in a problem-based manner. Knowing the common pain sources and being familiar with their US findings will help radiologists to perform accurate and effective US examinations.

Problem Solved: Integral Applications of Musculoskeletal Ultrasound

Musculoskeletal ultrasound has grown substantially in use over the past several years as an indispensable companion to magnetic resonance imaging and other imaging modalities. This article reviews 10 integral applications of musculoskeletal ultrasound as a problem-solving tool with correlative case examples. These applications include the following: (1) accessibility and portability, (2) targeted imaging, (3) dynamic imaging, (4) contralateral comparison, (5) Doppler imaging, (6) increased spatial resolution, (7) solid versus cystic comparison, (8) posttraumatic imaging, (9) postsurgical imaging, and (10) treatment delivery and optimization. The review will help the radiologist recognize the complementary uses of musculoskeletal ultrasound with radiography, computed tomography, and magnetic resonance imaging.

Diagnostic Value of Dynamic High-frequency Ultrasound for the Slipping Rib and Twelfth Rib Syndrome: A Case Series with Review

BACKGROUND

High-frequency ultrasound (HFUS) is a mobile, radiation-free imaging tool for the diagnosis of musculoskeletal disorders. We aim to demonstrate the diagnostic value of dynamic HFUS for undiagnosed lower chest, upper abdomen, and loin pain with this case series.

CASE SERIES

A cricketer presented with long-standing left-sided dull ache lower chest and upper abdominal pain, aggravated on exertion and leaning forward. His previous laboratory and previous imaging tests were unrevealing. Dynamic HFUS of his left ribs during hooking maneuver demonstrated slipping of the eighth rib over the seventh rib associated with clicking. He also reported tenderness over this region. He was diagnosed with slipping rib syndrome (SRS), and was treated with the eighth nerve block under the HFUS guidance. The second and third cases presented with chronic undiagnosed waxing and waning loin pain despite extensive laboratory and radiological workup. Both patients demonstrated twelfth rib HFUS probe tenderness in a sitting position with a specific movement that reproduced the pain during the dynamic HFUS study. The diagnosis of twelfth rib syndrome (TRS) was confirmed and treated successfully with a local intercostal nerve block.

REVIEW OF THE LITERATURE

HFUS is the most underutilized imaging tool for the diagnosis of unexplained upper abdominal and lower chest pain syndromes. We identified only a few such reported cases managed with the help of HFUS.

CONCLUSION

The dynamic HFUS is a valuable imaging modality for the undiagnosed lower chest, upper abdominal, or loin pain.

Magnetic resonance imaging of the ankle and foot

This article reviews the magnetic resonance imaging (MRI) findings of the normal anatomy and various pathologic conditions of the ankle and foot commonly encountered in clinical practice. The spectrum of entities discussed includes osseous and osteochondral injuries, ligamentous injuries, common traumatic and degenerative tendon pathology, abnormalities of transverse tarsal joint (Chopart) and tarsometatarsal joint (Lisfranc) complexes, pathological conditions affecting capsuloligamentous structures of the great toe and lesser toes, as well as pedal infection, with a focus on diabetic osteomyelitis and neuropathic osteoarthropathy.

Changes in Current Procedural Terminology Coding and Its Effect on Specialty-Level Utilization of Musculoskeletal Ultrasound

PURPOSE

Concerns regarding increasing utilization of non-vascular extremity ultrasound (US) imaging led to the Current Procedural Terminology (CPT) Editorial Panel separating a singular billing code into distinct comprehensive and focused examination codes with differential reimbursement. We explore this policy change's temporal association with utilization.

METHODS

Using Physician/Supplier Procedure Summary Master Files, we identified all nonvascular extremity US services billed for Medicare fee-for-service beneficiaries between 1994 and 2017. These included generic (CPT code 76880 from 1994 to 2010), complete (code 76881 from 2011 to 2017), and limited (code 76882 from 2011 to 2017) examinations. Annual utilization per 100,000 beneficiaries was computed and stratified by billing specialty. Compound annual growth rates were calculated.

RESULTS

Radiologists and podiatrists were the top 2 billing specialties for nonvascular extremity US examinations. From 1994 to 2010, radiologist services increased 6.1% annually. Following the 2011 code separation, radiologists' utilization increased 2.7% annually for complete and 12.3% for limited exams. Between 1994 and 2017, radiologists' market share decreased 72.8% to 40.4%. From 1994 to 2010, podiatrist services increased 87.1% annually. Following the code separation, podiatrists' annual utilization growth stabilized 0.4% for complete and 0.6% for limited exams. Podiatrists' market share was 9.1% in 2001, peaked at 31.3% in 2009, and declined to 14.3% in 2017.

CONCLUSIONS

Prior rapid growth in extremity nonvascular US for podiatrists slowed considerably following CPT code separation in 2011. Subsequent service growth has largely been related to less costly, focused examinations performed by radiologists. Further study may help better understand how CPT coding changes alter imaging utilization more broadly.

The peroneus longus muscle and tendon: a review of its anatomy and pathology

This article will review the anatomy and common pathologies affecting the peroneus longus muscle and tendon. The anatomy of the peroneus longus is complex and its long course can result in symptomatology referable to the lower leg, ankle, hindfoot, and plantar foot. Proximally, the peroneus longus muscle lies within the lateral compartment of the lower leg with its distal myotendinous junction arising just above the level of the ankle. The distal peroneus longus tendon has a long course and makes two sharp turns at the lateral ankle and hindfoot before inserting at the medial plantar foot. A spectrum of pathology can occur in these regions. At the lower leg, peroneus longus muscle injuries (e.g., denervation) along with retromalleolar tendon instability/subluxation will be discussed. More distally, along the lateral calcaneus and cuboid tunnel, peroneus longus tendinosis and tears, tenosynovitis, and painful os peroneum syndrome (POPS) will be covered. Pathology of the peroneus longus will be illustrated using clinical case examples along its entire length; these will help the radiologist understand and interpret common peroneus longus disorders.

ACR Appropriateness Criteria® Chronic Ankle Pain

Chronic ankle pain is a common clinical problem whose cause is often elucidated by imaging. The ACR Appropriateness Criteria for chronic ankle pain define best practices of image ordering. Clinical scenarios are followed by the imaging choices and their appropriateness. The information is in ordered tables with an accompanying narrative explanation to guide physicians to order the right test. 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.

High-Frequency Color Doppler Ultrasound in Diagnosis, Treatment, and Rehabilitation of Achilles Tendon Injury

Background

This study evaluated the clinical application of high-frequency color Doppler ultrasonography (HFCDU) in the diagnosis, treatment, and rehabilitation of Achilles tendon injury.

Material/Methods

A total of 68 patients with suspected Achilles tendon injury were examined by HFCDU. There were 42 Achilles tendon injury patients who underwent surgery, and they were randomly divided into a routine treatment group (n=21) and a rehabilitation group (n=21). HFCDU was performed at weeks 1, 3, 6, and 9, and months 3, 6, 9, 12, and 24 after the operation. The thickness of the injured Achilles tendon, echo, blood flow, and tissue adhesion were compared to those of the uninjured side.

Results

Of the 68 patients, 14 had normal ultrasound presentation with strong echo; 7 had laceration, presenting as swelling and decreased echo; 26 had partial tear, presenting as discontinued rupture with no or low echo; 19 had complete rupture, presenting as discontinued fibers with hypoechoic hemorrhage and hyperechoic fat tissue between ends; 1 had plantar tendon rupture and periapical hemorrhage; and 1 had acute Achilles tendonitis. The postoperative tendon thickness decreased over time, echo turned homogeneous, blood flow and adhesions decreased, and these results were consistent with clinical symptoms. Patient condition and ultrasound recovery were better in the rehabilitation group, and the diameter of the injured tendon increased compared with the uninjured side.

Conclusions

HFCDU can determine the types and extent of tendon injuries, and can help in the diagnosis, treatment, and rehabilitation of Achilles tendon injury.

Peroneal tendon pathology: Pre- and post-operative high resolution US and MR imaging

Peroneal tendon pathology is an important cause of lateral ankle pain and instability. Typical peroneal tendon disorders include tendinitis, tenosynovitis, partial and full thickness tendon tears, peroneal retinacular injuries, and tendon subluxations and dislocations. Surgery is usually indicated when conservative treatment fails. Familiarity with the peroneal tendon surgeries and expected postoperative imaging findings is essential for accurate assessment and to avoid diagnostic pitfalls. Cross-sectional imaging, especially ultrasound and MRI provide accurate pre-operative and post-operative evaluation of the peroneal tendon pathology. In this review article, the normal anatomy, clinical presentation, imaging features, pitfalls and commonly performed surgical treatments for peroneal tendon abnormalities will be reviewed. The role of dynamic ultrasound and kinematic MRI for the evaluation of peroneal tendons will be discussed. Normal and abnormal postsurgical imaging appearances will be illustrated.

Soleus Muscle Herniation With Magnetic Resonance Imaging and Ultrasound Correlation in a Female Long-Distance Runner: A Case Report

This is a case of a 40-year-old female endurance athlete with right leg pain while running. A comprehensive workup revealed a fascial defect with soleus muscle herniation. Although historically in many practice settings magnetic resonance imaging is the diagnostic imaging modality of choice for suspected muscle herniation through the fascia, the use of ultrasound is increasing because of lower cost, ease of access, and dynamic evaluation. To the authors' knowledge, there has not been a direct comparison between the accuracy of magnetic resonance imaging versus ultrasound in determining the size or location of a soleus muscle herniation.

LEVEL OF EVIDENCE

Not applicable.

An orthopedist's guide to shoulder ultrasound: a systematic review of examination protocols

BACKGROUND

The utilization of musculoskeletal ultrasound has expanded within the setting of the orthopedic clinic as a cost-effective, point-of-care diagnostic tool for shoulder pathology. In experienced hands, ultrasound exhibits capabilities equivalent to that of magnetic resonance imaging in the diagnosis of many shoulder diseases including full-thickness and partial-thickness rotator cuff tears. Although similarly effective in identifying additional shoulder disease processes, major obstacles to its widespread use include user dependence and intrinsic limitation to extra-articular diagnosis.

OBJECTIVES

The purpose of this review is to present a step-by-step guide of how to perform a comprehensive shoulder examination and to discuss the appropriate use, economic benefit and implementation of ultrasound within the clinic.

METHODS

A systematic search (June 2016) of PubMed, Scopus, and EMBASE databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for literature presenting shoulder ultrasound examination protocols. Included studies were peer-reviewed articles or academic society endorsed protocols presenting comprehensive sonographic examinations of the adult shoulder. Papers with limited or single structure examination descriptions, non-English language, and publication dates before 1980 were excluded. Final papers meeting criteria were secondarily screened for publication after 2005 to reflect the current state of ultrasound imaging.

RESULTS AND CONCLUSIONS

The search yielded 1,725 unique articles with 17 studies meeting final selection criteria. Information from identified studies was summarized to formulate a 4-part shoulder examination protocol, including steps most pertinent to orthopedic in-office diagnoses. In agreement with previous studies, the inexperienced orthopedic surgeon can be quickly trained to expert level proficiency in shoulder ultrasound diagnosis. Using an established protocol, a comprehensive, yet effective shoulder ultrasound examination can be performed within ten minutes. Further, ultrasound provides opportunity to off-set costs through the engagement of revenue generating activity for the orthopedic practice.

Correlation Between Sonographic and In Vivo Measurement of A1 Pulleys in Trigger Fingers

The thickness of 210 A1 pulleys of 21 male and female healthy volunteers in two different age groups (20-35 y and 50-70 y) were measured by ultrasound. In a second group, the thickness of 15 diseased A1 pulleys and 15 A1 pulleys of the corresponding other hand of 10 patients with the clinical diagnosis of trigger finger were measured by ultrasound. During open trigger finger release, a strip of A1 pulley was excised and immediately measured using an electronic caliper. The average pulley thickness of healthy volunteers was 0.43-0.47 mm, compared to 0.77-0.79 mm in patients with trigger finger. Based on the receiver operating characteristic (ROC) curve, a diagnostic cut-off value of the pulley thickness at 0.62 mm was defined in order to differ a trigger finger from a healthy finger (sensitivity and specificity of 85%). The correlation between sonographic and effective intra-operative measurements of pulley thickness was linear and very strong (Pearson coefficient 0.86-0.90). In order to distinguish between healthy and diseased A1 pulleys, 0.62 mm is a simple value to use, which can be applied regardless of age, sex, body mass index (BMI) and height in adults.

Dynamic sonography of snapping hip due to gluteus maximus subluxation over greater trochanter

We report on the dynamic sonographic findings of a 10-year-old avid female dancer who presented with symptoms of abrupt left hip motion and associated painful snapping sensation while performing lateral motions of the pelvis suggesting external snapping hip syndrome. Dynamic sonographic evaluation of both hips demonstrated that symptoms were due to gluteus maximus subluxation over the greater trochanter. This etiology of external snapping hip syndrome is rare with limited imaging descriptions in the literature. We present case history, physical examination, and dynamic ultrasound examination, including multiple still images and cine clips, comprehensively characterizing this uncommon source of external snapping hip syndrome.

High-resolution US and MR imaging of peroneal tendon injuries

Injuries of the peroneal tendon complex are common and should be considered in every patient who presents with chronic lateral ankle pain. These injuries occur as a result of trauma (including ankle sprains), in tendons with preexisting tendonopathy, and with repetitive microtrauma due to instability. The peroneus brevis and peroneus longus tendons are rarely torn simultaneously. Several anatomic variants, including a flat or convex fibular retromalleolar groove, hypertrophy of the peroneal tubercle at the lateral aspect of the calcaneus, an accessory peroneus quartus muscle, a low-lying peroneus brevis muscle belly, and an os peroneum, may predispose to peroneal tendon injuries. High-resolution 1.5-T and 3-T magnetic resonance (MR) imaging with use of dedicated extremity coils and high-resolution ultrasonography (US) with high-frequency linear transducers and dynamic imaging are proved to adequately depict the peroneal tendons for evaluation and can aid the orthopedic surgeon in injury management. An understanding of current treatment approaches for partial- and full-thickness peroneal tendon tears, subluxation and dislocation of these tendons with superior peroneal retinaculum (SPR) injuries, intrasheath subluxations, and peroneal tendonopathy and tenosynovitis can help physicians achieve a favorable outcome. Patients with low functional demands do well with conservative treatment, while those with high functional demands may benefit from surgery if nonsurgical treatment is unsuccessful. Radiologists should recognize the normal anatomy and specific pathologic conditions of the peroneal tendons at US and MR imaging and understand the various treatment options for peroneal tendon and SPR superior peroneal retinaculum injuries. Online supplemental material is available for this article.

The utility of ultrasound in the assessment of traumatic peripheral nerve lesions: report of 4 cases

Ultrasound technology continues to improve with better image resolution and availability. Its use in evaluating peripheral nerve lesions is increasing. The current review focuses on the utility of ultrasound in traumatic injuries. In this report, the authors present 4 illustrative cases in which high-resolution ultrasound dramatically enhanced the anatomical understanding and surgical planning of traumatic peripheral nerve lesions. Cases include a lacerating injury of the sciatic nerve at the popliteal fossa, a femoral nerve injury from a pseudoaneurysm, an ulnar nerve neuroma after attempted repair with a conduit, and, finally, a spinal accessory nerve injury after biopsy of a supraclavicular fossa lesion. Preoperative ultrasound images and intraoperative pictures are presented with a focus on how ultrasound aided with surgical decision making. These cases are set into context with a review of the literature on peripheral nerve ultrasound and a comparison between ultrasound and MRI modalities.

Sonographic evaluation of the iliotibial band at the lateral femoral epicondyle: does the iliotibial band move?

OBJECTIVES

The purpose of this study was to determine whether the iliotibial band (ITB) moves relative to the lateral femoral epicondyle (LFE) as a function of knee flexion in both non-weight-bearing and weight-bearing positions in asymptomatic recreational runners.

METHODS

Five male and 15 female asymptomatic recreational runners (10-30 miles/wk) aged 18 to 40 years were examined with sonography to assess the distance between the anterior fibers of the ITB and the LFE in full extension, 30° of knee flexion, and 45° of knee flexion. Measurements were obtained on both knees in the supine (non-weight-bearing) and standing (weight-bearing) positions.

RESULTS

The distance between the anterior fibers of the ITB and the LFE decreased significantly from full extension to 45° of knee flexion in both supine (0.38-cm average decrease; P < .001) and standing (0.71-cm average decrease; P < .001) positions. These changes reflect posterior translation of the ITB during the 0° to 45° flexion arc of motion in both the supine and standing positions.

CONCLUSIONS

Sonographic evaluation of the ITB in our study population clearly revealed anteroposterior motion of the ITB relative to the LFE during knee flexion-extension. Our results indicate that the ITB does in fact move relative to the femur during the functional ranges of knee motion. Future investigations examining ITB motion in symptomatic populations may provide further insight into the pathophysiologic mechanisms of ITB syndrome and facilitate the development of more effective treatment strategies.

The value of high-frequency ultrasonographic imaging for quantifying trigger digits: a correlative study with clinical findings in patients with different severity grading

Trigger digit is recognized as thickening and constriction of the flexor tendon sheath at the base of digits. This study investigates the correlation between the severity grading of trigger digits and clinical findings from high-frequency ultrasonography. We measured and compared thicknesses, areas and pathological changes of the flexor digit tendons among total, contracture and noncontracture trigger digits and noninvolved contralateral digits. Forty-seven patients with 55 idiopathic trigger digits (36 contracture and 19 noncontracture) and 55 noninvolved contralateral digits were examined using high-frequency ultrasonography. The thickness of the flexor tendons was measured in a longitudinal plane at the A1 pulley: Inlet (metacarpal head-neck junction), Outlet (proximal phalangeal base-shaft junction) and Interpulley (middle of Inlet and Outlet). The cross-sectional and extratendinous tissue areas of the flexor tendons in a transverse plane at the point of Interpulley were measured. Pathological changes including irregular internal echotextures, fluid collection, dominant A1 pulley and abnormal metacarpophalangeal joint were analyzed. All thicknesses and areas of total and contracture trigger digits were significantly greater than those of noninvolved contralateral digits (p < 0.05), whereas no significant difference was observed in noncontracture trigger digits. The pathological changes were all significantly different from noninvolved contralateral digits in total, contracture and noncontracture trigger digits (p < 0.05). In contracture and noncontracture trigger digits, there were significant differences only in the thickness of the Inlet and the pathological change of the dominant A1 pulley (p < 0.05). In conclusion, the results of the ultrasonographic measurements and findings provided evidence of Notta's node and correlated with clinical findings and severity grades.

Ultrasonography of the shoulder with arthroscopic correlation

Ultrasonography is a well-established and widely accepted modality for the evaluation of rotator cuff tears and injury to the biceps brachii tendon. Ultrasonography and magnetic resonance imaging have comparable sensitivity and specificity for diagnosing both full-thickness and partial-thickness rotator cuff tears. This article addresses the ultrasonographic diagnosis of abnormalities of the rotator cuff, rotator interval, and biceps brachii, with magnetic resonance imaging and arthroscopic correlation. Characteristic ultrasonographic findings as well as imaging pitfalls are reviewed.

Dynamic ultrasonography: a cadaveric model for evaluating aseptic loosening of total ankle arthroplasty

Aseptic loosening is the primary method of failure in total ankle replacements. Currently, loosening is defined by morphologic changes in osseous architecture determined by plain radiography. The loss of bone noted at diagnosis presents difficulties in future ankle revisions. A method by which early aseptic loosening could be detected before bony deformation or reaction could lead to improved patient outcomes. A cadaveric fresh frozen ankle specimen (mid-tibia to include the foot) was used in the present study. An anterior approach to the ankle was performed. A total ankle prosthesis was implanted in the standard fashion (Salto Talaris, Tornier). The initial cuts were made for a size 1 ankle, and a size 1 ankle was implanted. Dynamic ultrasonography was used to evaluate the bone-implant interface. The prosthesis was removed, and sequential removal of bone was performed at the interface of the medial tibial tray until visible motion was seen with flexion and extension. The reimplanted prosthesis was then re-evaluated using dynamic ultrasonography and dynamic and static fluoroscopy. In the loose prosthesis model, dynamic ultrasonography was able to determine the motion at the bone-prosthesis interface. Dynamic ultrasonography might be a useful tool in the evaluation of early loosening in a total ankle arthroplasty model.

Sonographic appearance of nontraumatic tear of flexor carpi radialis muscle-a case report

We present an unusual case of a man with a nontraumatic tear of the flexor carpi radialis muscle after a regular swimming exercise, without known precipitation factors. The muscle tear was diagnosed by ultrasonography, which showed a cystic mass with increased peripheral vascularity, and was confirmed by magnetic resonance imaging. After conservative treatment, follow-up ultrasonography showed resolution of the hematoma. The patient was able to continue swimming without pain or limitation of function.

Snapping knee: imaging findings with an emphasis on dynamic sonography

OBJECTIVE

The purpose of this article is to illustrate the causes of snapping knee. The value of imaging techniques is discussed with an emphasis on dynamic sonography in light of the available surgical and radiologic literature.

CONCLUSION

Because of its dynamic capabilities, dynamic sonography provides real-time visualization of snapping knee syndrome and may be used as a first-line modality.

Paralabral cysts of the hip: sonographic evaluation with magnetic resonance arthrographic correlation

This retrospective study demonstrates the sonographic appearance paralabral cysts of the hip with magnetic resonance (MR) arthrography as the reference standard. Consensus review by 2 musculoskeletal radiologists was used to assess the paralabral cysts and determine their characteristics. The 3 paralabral cysts seen on sonography and confirmed with MR arthrography in this study were anechoic or hypoechoic, lobulated, and filled with contrast on MR imaging. A labral tear was also noted in all cases on both sonography and MR arthrography. Sonographic assessment for an anterior hip paralabral cyst and labral tear may be of diagnostic benefit.

Ultrasound of the knee

Ultrasound is one of the standard imaging modalities of the knee. In the recent decades many new ultrasound techniques have been introduced, including power Doppler, dynamic examination, and ultrasound-guided techniques. Some of them have clear advantages over magnetic resonance imaging-today's knee imaging gold standard-whereas others have failed to meet expectations. This pictorial article reviews and demonstrates the use of sonography in different knee joint pathologies underlining recent findings and their practical approach.

Ultrasound in the diagnosis of clinical orthopedics: The orthopedic stethoscope

Ultrasonography has advantages over other imaging modalities in terms of availability and comfort, safety, and diagnostic potential. Operating costs are low compared with both computed tomography (CT) and magnetic resonance imaging (MRI). The portable equipment is accessible at locations distant from medical centers. Importantly, ultrasonography is performed while patients lie in a comfortable position, without pain or claustrophobia. Ultrasonography is a totally safe noninvasive imaging technique. In contrast to CT and X-rays, it does not emit ionizing radiation. Unlike MRI, it is safe for all patients, including those with cardiac pacemakers and metal implants, without any contraindications. Of the many indications for musculoskeletal ultrasonography, the evaluation of soft tissue pathology is particularly common. In addition, ultrasonography is useful for the detection of fluid collection, and for visualization of cartilage and bone surfaces. Color or power Doppler provides important physiological information, including that relating to the vascular system. The capability of ultrasonography in delineating structures according to their echotextures results in excellent pictorial representation. This imaging principle is based on physical changes in composition, as compared to imaging with MRI, which is based on changes in chemical composition. This article reviews the contribution of sonography to the evaluation of the musculoskeletal system.

Ultrasonography of the shoulder

The shoulder is the most common region to be evaluated with musculoskeletal ultrasound. The shoulder's complex anatomy enables an exceptional range of mobility at the expense of static stability. Consequently, the shoulder is susceptible to a multitude of traumatic and atraumatic injuries. This article presents an overview of shoulder anatomy, recommends a standardized approach to the sonographic shoulder evaluation, and discusses common sonographically apparent pathology of the shoulder.

Snapping biceps femoris tendon: a dynamic real-time sonographic evaluation

Snapping of the distal arms of the biceps femoris tendon may explain pain and discomfort at the lateral aspect of the knee. We report two cases in which dynamic sonography was able to confirm the diagnosis and document which of the main arms was involved in the process.

[Ultrasound diagnostics of muscle and tendon injuries]

INTRODUCTION

Sonography is a useful technique for the investigation of a number of musculoskeletal disorders. The most common indication for ultrasonography of muscles and tendons is the diagnosis of traumatic lesions, distinguishing them from other disorders and follow- up of healing process.

OBJECTIVE

The purpose of this paper is to show the importance of ultrasound in the diagnosis of muscle and tendon injuries.

METHODS

The study included 170 patients (148 male and 22 female), mean age 29.6 years (range 14-60 years). All examinations were performed by linear transducer of 7.5-10 MHz, with longitudinal and transverse scanning. Ultrasound examination followed physical examination.

RESULTS

Traumatic lesions of muscles were diagnosed in 113 patients (66.7%) and tendon injuries in 57 cases (33.2%). The muscle changes detected by ultrasonography were the following: 70 (61.9%) partial and two (1.76%) complete ruptures, 22 (19.46%) haematoma, 9 (7.96%) strains grade I, 4 fibroses and 4 ossifying myositis 4 (3.5%, respectively). Complications of muscle injuries were diagnosed in two cases, a muscular hernia and an arteriovenous fistula. Among tendon injuries, 21 (33.8%) ruptures and 36 (66.1%) tendinitis were diagnosed. Accompanying effusion in the bursa of patients with tendon injuries was found in 9 cases.

CONCLUSION

Ultrasonography allowed visualization and objective assessment of the type and the extent of traumatic pathomorphological changes of muscles and tendons. Such diagnostic possibilities of ultrasonography are especially important in the choice of appropriate therapy.

Ultrasonographic assessment of clinically diagnosed trigger fingers

This study examines flexor digitorum tendons and A1 pulley in patients presenting trigger fingers using high-resolution ultrasonography (US), determines the accurate causes of trigger fingers, and analyzes the relationship between clinical data and US findings. As much as 50 trigger fingers of 41 patients were examined by high-resolution US, and the US findings were analyzed as tendon thickness, fibrillar echotexture, tendon margin, fluid collection, A1 pulley thickening, tendon sheath cyst, and metacarpophalageal (MCP) joint abnormalities. The affected fingers were compared with the asymptomatic opposite sides. Right thumb and ring finger were the most common fingers involved. Mean thickness of flexor digitorum tendons of the affected fingers was increased significantly, compared with that of the opposite fingers. There were various US findings in flexor digitorum tendons as follows; loss of normal fibrillar echogenic pattern (14%), irregularity or blurring of the tendon margin (62%), and fluid collection in the tendon sheath (16%). Thickening of A1 pulley was noted in 44% of fingers, and mean thickness of A1 pulley was 0.7 mm. As much as 6% of fingers had the sheath cysts and 4% of fingers had abnormalities of MCP joints. The patients with extension difficulty of the fingers had thicker flexor digitorum tendon than those without. The patients with locking fingers had more blurred margin of the tendon than those without. US can detect various lesions in clinical trigger fingers, and some US findings correlated with clinical findings.

Musculoskeletal ultrasound: focused impact on MRI

OBJECTIVE

This article will compare and contrast image interpretation, accuracy, observer variability, economic impact, and education with regard to musculoskeletal ultrasound and MRI because these factors will influence the growth of musculoskeletal ultrasound and the impact on MRI.

CONCLUSION

The use of musculoskeletal ultrasound continues to grow and there are a number of factors that impact MRI. The development of less expensive portable ultrasound machines has opened the market to nonradiologists, and applications for musculoskeletal ultrasound have broadened. Selective substitution of musculoskeletal ultrasound for MRI can result in significant cost saving to the health care system. Although this change could decrease the use of MRI, issues related to accuracy, variability, education, and competence must be addressed.