Ultrasound evaluations and guided procedures of the painful joint arthroplasty.

The purpose of this article is to describe the use of ultrasound for the diagnosis and treatment of painful joint arthroplasty. Ultrasound plays a crucial role in the diagnosis of the painful joint arthroplasty, especially given its unique dynamic capabilities, convenience, and high resolution. Ultrasound guidance is also instrumental for procedures in both diagnosing and in select cases, treating the painful joint arthroplasty. Topics to be discussed in this article include trends in arthroplasty placement, benefits of the use of ultrasound overall, and ultrasound evaluation of periprosthetic joint infections. We will also review the sonographic findings with dissociated/displaced components and adverse reaction to metallic debris including metallosis, trunnionosis, and metal-on-metal pseudotumors. Additionally, we will discuss ultrasound evaluation of tendon pathologies with arthroplasties, including dynamic maneuvers to evaluate for tendon impingement/snapping. Finally, we will cover ultrasound-guided joint arthroplasty injection indications and precautions. KEY POINTS: • Ultrasound is preferred over MRI in patients with joint arthroplasty and plays a crucial role in diagnosis, especially given its unique dynamic capabilities, convenience and high resolution. • It is especially beneficial for US-guided aspiration in periprosthetic joint infections; effectively used to evaluate periprosthetic fluid collections, facilitating differentiation between abscesses and aseptic collections, and tracking sinus tracts. • Recently, the diagnosis of periprosthetic joint infections has shifted focus to biomarkers in the periprosthetic fluid, specifically α-defensin, which has a high sensitivity and specificity for diagnosing infection. • Cutibacterium acnes is a major pathogen responsible for shoulder arthroplasty infections, often presenting with normal laboratory values and since slow growing, must be kept for a minimum of 14 days.

Thumb Injuries and Instabilities. Part 1: Anatomy, Kinesiology, and Imaging Techniques of the Thumb.

The unique anatomical characteristics of the thumb offer a broad range of motion and the ability to oppose thumb and finger, an essential function for grasping. The motor function of the thumb and its orientation make it particularly vulnerable to trauma. Pathologic lesions encountered in this joint are varied, and imaging techniques play a crucial role in injury detection and characterization. Despite advances in diagnostic accuracy, acute thumb injuries pose a challenge for the radiologist. The complex and delicate anatomy requires meticulous and technically flawless image acquisition. Standard radiography and ultrasonography are currently the most frequently used imaging techniques. Computed tomography is most often indicated for complex fractures and dislocations, and magnetic resonance imaging may be useful in equivocal cases. In this article, we present the relevant anatomy and imaging techniques of the thumb.

Thumb Injuries and Instabilities. Part 2: Spectrum of Lesions.

The motor function of the thumb and its alignment with regard to the hand make it particularly vulnerable to trauma. Pathology encountered in this joint is varied, and imaging techniques play a crucial role in the diagnosis and characterization of injury. Despite advances in imaging technology, acute thumb injuries remain a challenge for radiologists. Currently, standard radiography and ultrasonography are frequently used first-line imaging techniques. Computed tomography is most often indicated for complex fractures and dislocations. Magnetic resonance imaging may be used to optimally characterize soft tissues and bone marrow. In this article, we cover the most common traumatic injuries: fractures, dislocations, collateral ligament injuries of the metacarpophalangeal joint, as well as soft tissue lesions.

Peripheral Polyneuropathy Associated with COVID-19 in Two Patients: A Musculoskeletal Ultrasound Case Report.

As coronavirus disease 2019 (COVID-19) spreads, we are encountering multiple different symptoms and related complications. Although the vast majority of literature is focused on its pulmonary manifestations, recent reports have mentioned neurologic manifestations but typically those related to the central nervous system and diagnosed utilizing magnetic resonance imaging. We present two cases of COVID-19-associated peripheral polyneuropathy diagnosed utilizing musculoskeletal ultrasound (US), which to our knowledge is the first such case report. US is an instrumental portable modality that can be used for COVID-19 patients in isolation. As this virus continues to spread, understanding and recognizing these COVID-19 related complications and their sonographic findings are crucial.

The Hyperechoic Appearance of the Deltoid Muscle on Shoulder Ultrasound Imaging as a Predictor of Diabetes and Prediabetes.

OBJECTIVES: To evaluate whether the ultrasound appearance of the deltoid muscle in diabetic patients differs from that in obese nondiabetic patients. METHODS: Ultrasound images of the deltoid muscle from 137 type 2 diabetic patients (including 13 prediabetic patients) and 49 obese nondiabetic patients were blindly reviewed by 2 musculoskeletal radiologists, and by a third when arbitration was needed, to determine whether the appearance was "normal," "suspected diabetes," or "definite diabetes." Age, sex, race, body mass index (BMI), insulin use, and hemoglobin A1c were analyzed. This retrospective study included patients presenting between October 2005 and November 2017. Statistical analyses included a 2-sided sample t test or Wilcoxon rank sum test and a χ2 or Fisher exact test. Statistical significance was defined as P < .05. RESULTS: The type 2 diabetic patients included 98 women and 39 men aged 29 to 92 years, and the nondiabetic patients included 19 women and 30 men aged 18 to 75 years. A consensus diagnosis of definite diabetes by the musculoskeletal radiologists based on a hyperechoic deltoid was a powerful predictor of diabetes, with a positive predictive value of 89%. A hyperechoic deltoid was also a powerful predictor of prediabetes. Of the 13 prediabetic patients, all had the same hyperechoic appearance of the diabetic deltoid, regardless of BMI. Although obese diabetic patients more often had a diagnosis of definite diabetes, the BMI alone could not explain the increased echogenicity, as obese nondiabetic patients' deltoid muscles did not appear as hyperechoic and were correctly categorized as not having definite diabetes with 82% specificity. CONCLUSIONS: The characteristic hyperechoic deltoid appearance is a strong predictor of both diabetes and prediabetes and differs from that of obese nondiabetic patients.

Sonographic and radiographic findings of posterior tibial tendon dysfunction: a practical step forward.

The purpose of this article is to describe the sonographic and radiographic findings in the diagnosis and treatment of posterior tibial tendon dysfunction. Ultrasound and radiographs play a crucial role in the diagnosis of posterior tibial tendon dysfunction and in imaging the postoperative changes related to posterior tibial tendon dysfunction. Early detection and diagnosis of posterior tibial tendon dysfunction is important in helping to prevent further progression of disease, obviating the need for more invasive and complex procedures.

Compliance assessment and flip-angle measurement of the median nerve: sonographic tools for carpal tunnel syndrome assessment?

OBJECTIVES: To assess the diagnostic performance of median nerve (MN) flip-angle measurements, deformation during wrist flexion [transit deformation coefficient (TDC)], during compression [compression deformation coefficient (CDC)] and fascicular freedom to potentially identify fibrotic MN changes in patients with carpal tunnel syndrome (CTS). METHODS: This prospective study was performed with institutional review board approval; all participants provided oral and written informed consent. Wrists in 21 healthy participants and 29 patients with CTS were examined by ultrasound. MN movement during wrist flexion, MN deformation during transition over the flexor tendons (TDC) and during controlled compression (CDC) as well as fascicular freedom were assessed. Diagnostic properties of these parameters were calculated and compared to clinical findings and cross-section area measurements (ΔCSA). RESULTS: Low flip angles were associated with high ΔCSA at a receiver-operator characteristics area under the curve (AUC) of 0.62 (0.51-0.74). TDC [AUC, 0.83 (0.73-0.92), 76.3% (59.8-88.6%) sensitivity, 88.5% (76.6-95.7%) specificity], restricted fascicular movement [AUC, 0.86 (0.78-0.94), 89.5% (75.2-97.1%) sensitivity, 80.8% (67.5-90.4%) specificity] and compression-based CDC [AUC, 0.97 (0.94-1.00), 82.1% (66.5-92.5%) sensitivity, 94.2% (84.1-98.8%) specificity] demonstrated substantial diagnostic power (95% confidence intervals in parentheses). CONCLUSIONS: Fascicular mobility, TDC and CDC show substantial diagnostic power and may offer insights into the underlying pathophysiology of CTS. KEY POINTS: • Dynamic ultrasonography during wrist flexion and compression enables median nerve deformability assessment. • Overall, reduced median nerve deformability is highly indicative of CTS. • Median nerve compressibility shows higher diagnostic power than conventional cross-section area measurements.

Value of ultrasound before joint aspiration.

OBJECTIVE: The purpose of this article is to illustrate and discuss the value of ultra-sound screening before joint aspiration. CONCLUSION: Before joint aspiration, ultrasound assessment of the overlying and surrounding soft tissues requires little time and is relatively inexpensive. Bursal fluid collections, soft-tissue abscesses, and other fluid collections that would be undetected with fluoroscopy or blind aspiration can thus be identified. Ultrasound screening before joint aspiration can aid diagnosis and decrease the risk of iatrogenic complications.

Apophyseal injuries of the lesser tuberosity in adolescents: a series of five cases.

An isolated avulsion fracture of the lesser tuberosity is an uncommon injury. We present five cases in adolescent athletes which demonstrate the radiographic, ultrasound, and MR appearances of this injury. Clinically and radiologically, the diagnosis can be difficult. In a setting of trauma, careful review of the imaging studies can lead to early diagnosis and appropriate treatment.

Atypical rapid progression of osteoarticular amyloidosis involving the hip in a patient on hemodialysis using polyacrylonitrile membranes.

Amyloidosis related to dialysis is a well-known complication affecting many organ systems, in particular the musculoskeletal system. In 1985 Shirahama et al. (Biochem Biophys Res Commun 53:705-709, 1985) identified beta-2 microglobulin (MG) as the offending constituent by using protein purification techniques. Amyloidosis has been increasing in prevalence because of longer life spans and increased chronic medical conditions such as end-stage renal disease. When dialysis-related amyloidosis involves the musculoskeletal system, it affects the shoulder girdle, the so called shoulder pad sign, the wrist, hip, knee, and spine (Resnick, Diagnosis of bone and joint disorders, 4th edn., pp. 2054-2058 and 2176-2183, 2002). Other osteoarticular manifestations of amyloidosis include osteoporosis, lytic lesions, and pathologic fractures. It has been well documented that the prevalence of amyloid is dependent on duration of dialysis-over 90% in patients on dialysis for over 7 years (Jadoul, Nephrol Dial Transplant 13:61-64, 1998). However, a recent changeover to high-flux membranes used in hemofiltration has been reported to delay its onset (Campistol et al., Contrib Nephrol 125:76-85, 1999). We report on the radiographic, nuclear medicine, and computed tomography (CT) findings of osteoarticular amyloidosis involving the hip, and sequence its atypical rapid onset. The imaging, histopathological findings, and differential diagnosis are discussed.

Sonographic depiction of trigger fingers in acromegaly.

OBJECTIVE: The purpose of this study was to compare the prevalence of trigger fingers in patients with acromegaly versus an unaffected control group. METHODS: This study was performed with Institutional Review Board approval, and informed written consent was obtained from each patient and control participant. The diagnosis was made by a combination of clinical symptoms and sonographically measured thickening of the first annular (A1) pulley. The A1 pulley thickness was measured in 40 patients and 40 control participants by means of a 17-5 MHz high-resolution transducer. Thickening of the A1 pulley and abnormalities of the underlying flexor tendons associated with the clinical sign were diagnostic for a trigger finger. The acromegalic patients were divided into groups according to disease activity and therapy. The study was performed at the baseline and at a follow-up after 1 year. RESULTS: At the baseline, clinical and sonographic findings were consistent with trigger fingers in 25% of patients (6 at presentation and 4 with uncontrolled disease). After 1 year, the trigger fingers recovered in the patients who were not receiving any treatment at the beginning of the study. In patients with uncontrolled disease, the condition remained unchanged. The A1 pulley thickness was greater in the acromegalic patients than control participants (mean +/- SD, 0.44 +/- 0.19 versus 0.24 +/- 0.05 mm; P < .05). In the patients treated for acromegaly, the trigger fingers disappeared, and a reduction in the A1 pulley thickness was noted (P < .05) at the follow-up. CONCLUSIONS: Trigger fingers were observed in 25% of the acromegalic patients but in none of the control participants. The A1 pulley was significantly thicker in the acromegalic patients and normalized after 1 year in some who were treated for the disease.

Ultrasound of the rotator cuff with MRI and anatomic correlation.

Magnetic resonance imaging and high-resolution ultrasound (US) are frequently used for the detection of rotator cuff tears. The diagnostic yield of US is influenced by several factors as technique, knowledge of the imaging characteristics of anatomic and pathologic findings and of pitfalls. The purpose of this article is to illustrates that the standardized high-resolution US examination of the shoulder covers the entire rotator cuff and correlates with MR imaging and anatomic sections.

Radiography and US of os peroneum fractures and associated peroneal tendon injuries: initial experience.

PURPOSE: To retrospectively evaluate the imaging features of os peroneum fractures and associated peroneus longus tendon injuries at radiography and ultrasonography (US) and to retrospectively compare these imaging features with those of multipartite os peroneum. MATERIALS AND METHODS: Institutional review board approval was obtained and informed consent was waived for this HIPAA-compliant study. Retrospective review of findings in nine patients (five men, four women; age range, 35-59 years) with os peroneum fracture at radiography and lateral foot pain after injury who had undergone US of the foot was performed. Three patients underwent magnetic resonance (MR) imaging, and two underwent surgery. Os peroneum fragment separation and displacement relative to the calcaneocuboid joint were measured on radiographs. Os peroneum fracture and peroneus longus tendon injuries were characterized with US and MR imaging. Review of 43 foot radiographs obtained in 36 control subjects (eight men, 28 women; age range, 18-84 years) who were found to have an os peroneum at radiography but were asymptomatic in that area was completed to measure os peroneum distance from the calcaneocuboid joint and bipartite os peroneum fragment distraction. RESULTS: Os peroneum fragment separation of 6 mm or more or displacement of the proximal fragment by 10 mm or more on a lateral radiograph or 20 mm or more on an oblique radiograph was associated with full-thickness peroneus longus tendon tear in seven of seven patients (100%). Os peroneum fragment separation of 2 mm or less or proximal displacement of 8 mm or less was associated with normal tendons, partial-thickness tears, or tendinosis. In the control subjects, os peroneum location ranged from 7 mm proximal to 8 mm distal to the calcaneocuboid joint on lateral radiographs and from 9 mm proximal to 8 mm distal to the joint on oblique radiographs. Bipartite os peroneum fragment separation was 2 mm or less. CONCLUSION: Os peroneum fragment separation of 6 mm or more suggests os peroneum fracture and associated full-thickness peroneus longus tendon tear. Separation of 2 mm or less may be seen with nondisplaced os peroneum fractures and bipartite os peroneum.

Three-tesla imaging of the knee: initial experience.

PURPOSE: To assess 3-T imaging of the knee. MATERIALS AND METHODS: We reviewed 357 3-T magnetic resonance images of the knee obtained using a dedicated knee coil. From 58 patients who had arthroscopy we determined the sensitivity and specificity for anterior cruciate ligament (ACL) tear and medial and lateral meniscal tear. RESULTS: A chemical shift artifact showed prominently at 3 T even after improvements had been made by increasing the bandwidth. For complete ACL tear the sensitivity was 100% (95% confidence interval, CI, 75.30-100.00), and the specificity was 97.9% (95% CI 87.7-99.9). For the medial meniscus the sensitivity was 100.00% (95% CI 90.0-100.00), and the specificity was 83.3%(95% CI 66.6-95.3). For the lateral meniscus the sensitivity was 66.7% (95% CI 38.4-88.2), and the specificity was 97.6% (95% CI 87.1-99.9). CONCLUSIONS: In general 3-T imaging allows a favorable display of anatomy and pathology. The lateral meniscus was assessed to be weaker than the other anatomic structures. Three-tesla imaging allows increased signal-to-noise ratio, increased resolution, and faster scanning times.

Soft-tissue lipomas: accuracy of sonography in diagnosis with pathologic correlation.

PURPOSE: To retrospectively determine the accuracy of sonography in helping to distinguish soft-tissue lipomas from other soft-tissue masses by using histologic proof as the reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was waived. Thirty-nine patients who underwent sonographic evaluation of a soft-tissue mass followed by biopsy or resection were retrospectively evaluated. Two musculoskeletal radiologists (readers 1 and 2) reviewed the sonographic images, characterized the masses, and rated the level of confidence in the diagnosis of lipoma by using a five-point scale. A level of confidence was also rated for the prospective sonographic report, which was reviewed and designated as reader 3. Receiver operating characteristic (ROC) curves, including 95% confidence intervals, were generated, and the area under the ROC curve (A(z)) was calculated for each reader. Sensitivity, specificity, and accuracy for each reader were calculated by using a confidence rating of 4 or 5 as positive for lipoma. Weighted kappa analysis was also performed to assess for interobserver variability. RESULTS: Histologic examination yielded 25 lipomas and 14 nonlipomas. The echogenicity of lipomas ranged from hypoechoic to hyperechoic relative to muscle, although most were isoechoic or hyperechoic. A(z) values were 0.79 for reader 1, 0.56 for reader 2, and 0.77 for reader 3. There was no significant difference between the A(z) for each reader and for chance. Interobserver agreement was fair, with a kappa value of 0.35 among the three readers. Sensitivities were 52%, 40%, and 52%, and accuracies were 64%, 49%, and 64% for readers 1, 2, and 3, respectively. CONCLUSION: Sonography demonstrates low accuracy in the diagnosis of soft-tissue lipomas.

Full-thickness and partial-thickness supraspinatus tendon tears: value of US signs in diagnosis.

PURPOSE: To determine which US signs are important in the diagnosis of a surgically identifiable supraspinatus tendon tear. MATERIALS AND METHODS: Fifty consecutive ultrasonographic (US) studies of the shoulder in patients who underwent arthroscopic follow-up were retrospectively reviewed by a musculoskeletal radiologist. US images of the supraspinatus tendon were evaluated for tendon nonvisualization, abnormal tendon echogenicity, tendon thinning, greater tuberosity cortical irregularity, cartilage interface sign, joint fluid, and subacromial-subdeltoid bursal fluid. US findings were compared with arthroscopic results. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each US sign in the diagnosis of full-thickness tendon tear and again for any type of supraspinatus tendon tear. RESULTS: Arthroscopy revealed 21 full-thickness tears, five bursal surface partial-thickness tears, 10 articular surface partial-thickness tears, and 14 patients without tear of the supraspinatus tendon. The presence of greater tuberosity cortical irregularity and joint fluid was most important in the diagnosis of full-thickness supraspinatus tendon tear (sensitivity, 60%; specificity, 100%; positive predictive value, 100%; negative predictive value, 78%; accuracy, 84%). For diagnosis of any type of supraspinatus tendon tear (partial or full thickness), tendon nonvisualization, greater tuberosity cortical irregularity, and cartilage interface sign are most important, although a combination of signs did not improve accuracy. CONCLUSION: Secondary US signs, such as greater tuberosity cortical irregularity and joint fluid, are most valuable in the diagnosis of supraspinatus tendon tear.