Ultrasonography for the Busy Orthopaedic Surgeon: The Upper Extremity.

Ultrasonography is increasingly used in the diagnosis and treatment of musculoskeletal conditions and injuries. Ultrasonography possesses multiple advantages compared with other methods of imaging, including low cost, lack of radiation exposure, speed, and means for dynamic examination. Because of these advantages, many orthopaedic surgeons are routinely using ultrasonography to diagnose musculoskeletal conditions of the upper extremity. Musculoskeletal ultrasonography is technically challenging, but with proper guidance and practice, every orthopaedic surgeon can confidently integrate ultrasonography into their clinical practice.

Ultrasonography for the Busy Orthopaedic Surgeon: The Lower Extremity.

Ultrasonography has the potential to become a fundamental component of the diagnosis and management of musculoskeletal conditions and injuries. Moreover, in the context of modern healthcare systems that are focused on optimizing value, ultrasonography has the advantage of minimizing costs when compared with other advanced imaging modalities. Because of its low cost, lack of radiation exposure, speed, and capability to diagnose dynamic conditions, more orthopaedic surgeons are routinely integrating musculoskeletal ultrasonography into their daily practice. It is important to provide a comprehensive review of and approach to common musculoskeletal conditions of the lower extremity for the busy orthopaedic surgeon.

Effects of a Neonicotinoid Insecticide and Population Density on Behavior and Development of Wood Frogs (Rana sylvatica).

Amphibians have been facing global declines over the last decades from direct and indirect effects of anthropogenic activities. A contributor to declines is waterway contamination from agricultural runoffs of pesticides such as neonicotinoids. Beyond direct and indirect effects of the pesticide, few studies have investigated the possible interactions between neonicotinoids and natural environmental stressors across larval development, which could alter the strength and direction of observed neonicotinoid effects. The present study used a fully crossed design to investigate how a concentration of imidacloprid (a neonicotinoid; 10 µg/L) measured in surface waters interacted with low and high population densities (0.33 and 1 tadpole/L, respectively), an important environmental stressor, to influence behavior and development across metamorphosis in wood frogs (Rana sylvatica), known to breed in agricultural landscapes. Behaviors were measured in the absence and presence of predation cues using open-field tests at three distinct developmental stages, up to the metamorph stage. We found that imidacloprid did not interact with population density or independently affect behaviors in the absence of predation cues. However, individuals raised at high density compared with low density were more active at an early developmental stage but less active at metamorphic climax. Furthermore, both density and imidacloprid independently decreased the natural freezing response of tadpoles to predation cues. Finally, we found that distance traveled in the open-field test was weakly repeatable between aquatic stages but not repeatable across metamorphosis, a pattern that was not affected by treatments. The present study provides novel insights on the ecotoxicology of imidacloprid in the presence of a natural stressor, highlighting the importance of including behavioral assays and natural stressors in studies of amphibian ecotoxicology. Environ Toxicol Chem 2022;41:2968-2980. © 2022 SETAC.

Intercellular communication controls agonist-induced calcium oscillations independently of gap junctions in smooth muscle cells.

In this study, we report the existence of a communication system among human smooth muscle cells that uses mechanical forces to frequency modulate long-range calcium waves. An important consequence of this mechanical signaling is that changes in stiffness of the underlying extracellular matrix can interfere with the frequency modulation of Ca2+ waves, causing smooth muscle cells from healthy human donors to falsely perceive a much higher agonist dose than they actually received. This aberrant sensing of contractile agonist dose on stiffer matrices is completely absent in isolated smooth muscle cells, although the isolated cells can sense matrix rigidity. We show that the intercellular communication that enables this collective Ca2+ response in smooth muscle cells does not involve transport across gap junctions or extracellular diffusion of signaling molecules. Instead, our data support a collective model in which mechanical signaling among smooth muscle cells regulates their response to contractile agonists.

Variable impact of tizanidine on the medium latency reflex of upper and lower limbs.

Sudden limb displacement evokes a complex sequence of compensatory muscle activity. Following the short-latency reflex and preceding voluntary reactions is an epoch termed the medium-latency reflex (MLR) that could reflect spinal processing of group II muscle afferents. One way to test this possibility is oral ingestion of tizanidine, an alpha-2 adrenergic agonist that inhibits the interneurons transmitting group II signals onto spinal motor neurons. We examined whether group II afferents contribute to MLR activity throughout the major muscles that span the elbow and shoulder. MLRs of ankle muscles were also tested during walking on the same day, in the same participants as well as during sitting in a different group of subjects. In contrast to previous reports, the ingestion of tizanidine had minimal impact on MLRs of arm or leg muscles during motor actions. A significant decrease in magnitude was observed for 2/16 contrasts in arm muscles and 0/4 contrasts in leg muscles. This discrepancy with previous studies could indicate that tizanidine's efficacy is altered by subtle changes in protocol or that group II afferents do not substantially contribute to MLRs.

Utilization of sonography and a stress device in the assessment of partial tears of the ulnar collateral ligament in throwers.

The non-invasive assessment of medial elbow pain in throwers can be challenging. Valgus stress transmitted to the elbow during the late cocking and acceleration phases of the throwing motion can result in injury to the medial ligamentous structures of the elbow, bony surfaces, and common tendon of the forearm flexors. The utilization of musculoskeletal (MSK) ultrasound in combination with the Telos Stress Device (TSD) (Austin & Associates Fallston, MD) can be an alternate quick assessment when radiography is not be available.

Snowboarding injuries: a review of the literature and an analysis of the potential use of portable ultrasound for mountainside diagnostics.

Snowboarding has become a popular recreational and professional sport. Participants suffer a variety of injuries, especially of the extremities, that require medical evaluation. This article reviews the reported injuries to both leisure and elite athletes. To many, an injured extremity requires travel to a medical facility for accurate evaluation. Musculoskeletal ultrasound is an accurate and portable technology that can be used for real time, mountainside diagnoses of these injuries.

A pilot study of comprehensive ultrasound education at the Wayne State University School of Medicine: a pioneer year review.

OBJECTIVE: Ultrasound is a versatile diagnostic modality used in a variety of medical fields. Wayne State University School of Medicine (WSUSOM) is one of the first medical schools in the United States to integrate an ultrasound curriculum through both basic science courses and clinical clerkships. METHODS: In 2006, 25 portable ultrasound units were donated to WSUSOM. First-year medical students were provided an ultrasound curriculum consisting of 6 organ-system sessions that addressed the basics of ultrasound techniques, anatomy, and procedural skills. After the last session, students were administered 2 anonymous and voluntary evaluations. The first assessed their overall experience with the ultrasound curriculum, and the second assessed their technical skills in applying ultrasound techniques. RESULTS: Eighty-three percent of students agreed or strongly agreed that their experience with ultrasound education was positive. On the summative evaluation, nearly 91% of students agreed or strongly agreed that they would benefit from continued ultrasound education throughout their 4 years of medical school. Student performance on the technical assessment was also very positive, with mean class performance of 87%. CONCLUSIONS: As residency programs adopt ultrasound training, medical school faculty should consider incorporating ultrasound education into their curriculum. Portable ultrasound has the potential to be used in many different settings, including rural practice sites and sporting events. The WSUSOM committee's pilot ultrasound curriculum will continue to use student feedback to enhance the ultrasound experience, helping students prepare for challenges that they will face in the future.

Battling fire and ice: remote guidance ultrasound to diagnose injury on the International Space Station and the ice rink.

BACKGROUND: National Aeronautical and Space and Administration (NASA) researchers have optimized training methods that allow minimally trained, non-physician operators to obtain diagnostic ultrasound (US) images for medical diagnosis including musculoskeletal injury. We hypothesize that these techniques could be expanded to non-expert operators including National Hockey League (NHL) and Olympic athletic trainers to diagnose musculoskeletal injuries in athletes. METHODS: NHL and Olympic athletic trainers received a brief course on musculoskeletal US. Remote guidance musculoskeletal examinations were conducted by athletic trainers, consisting of hockey groin hernia, knee, ankle, elbow, or shoulder evaluations. US images were transmitted to remote experts for interpretation. RESULTS: Groin, knee, ankle, elbow, or shoulder images were obtained on 32 athletes; all real-time US video stream and still capture images were considered adequate for diagnostic interpretation. CONCLUSIONS: This experience suggests that US can be expanded for use in locations without a high level of on-site expertise. A non-physician with minimal training can perform complex, diagnostic-quality examinations when directed by a remote-based expert.

Optimization and scale-up of a fluid bed tangential spray rotogranulation process.

The production of pellets in the pharmaceutical industry generally involves multi-step processing: (1) mixing, (2) wet granulation, (3) spheronization and (4) drying. While extrusion-spheronization processes have been popular because of their simplicity, fluid-bed rotogranulation (FBRG) is now being considered as an alternative, since it offers the advantages of combining the different steps into one processing unit, thus reducing processing time and material handling. This work aimed at the development of a FBRG process for the production of pellets in a 4.5-l Glatt GCPG1 tangential spray rotoprocessor and its optimization using factorial design. The factors considered were: (1) rotor disc velocity, (2) gap air pressure, (3) air flow rate, (4) binder spray rate and (5) atomization pressure. The pellets were characterized for their physical properties by measuring size distribution, roundness and flow properties. The results indicated that: pellet mean particle size is negatively affected by air flow rate and rotor plate speed, while binder spray rate has a positive effect on size; pellet flow properties are enhanced by operating with increased air flow rate and worsened with increased binder spray rate. Multiple regression analysis enabled the identification of an optimal operating window for production of acceptable pellets. Scale-up of these operating conditions was tested in a 30-l Glatt GPCG15 FBRG.

Relationship between radiation injury and Alzheimer-related neurodegenerative changes.

The relationship between radiation injury and other neurodegenerative changes such as the formation of neuritic or diffuse plaques and tangles have received little attention in the literature. In the current study, archival tissue was examined from 485 patients with the diagnosis of either a primary or metastatic brain tumor, who had received radiation therapy between the initial and subsequent pathological study (either surgical or autopsy). Of those cases, 20 were identified that also contained cerebral cortex in both specimens. Sections were stained with the modified Bielschowsky technique and immunohistochemical preparations for beta-amyloid. Contrary to previous reports, the present study did not identify neurodegenerative changes typical of Alzheimer's disease as a consequence of radiation therapy.

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.

Ultrasound for the early diagnosis of clinically suspected scaphoid fracture.

PURPOSE: To test the ability of ultrasound to diagnose clinically suspected occult scaphoid fractures. METHODS: Eighteen wrists in 18 patients with an average age of 35 years (range, 10-77 years) were seen in the emergency room, each with a single traumatic wrist injury, snuffbox tenderness, swelling, and a negative wrist x-ray result. They were evaluated in this prospective, blind, controlled study by physical examination, x-ray, and high-resolution ultrasound. One hand surgeon performed the examination, and ultrasounds were read by a musculoskeletal radiologist. Patients were immobilized in a thumb spica splint and then seen in the office 1 to 14 days after the emergency room visit, at which time a repeat physical examination, wrist x-ray, and the single investigative ultrasound were done using the opposite wrist as a control. All patients were immobilized and evaluated until symptoms resolved or x-ray showed scaphoid fracture site resorption or callus, in which case they were kept immobilized until healed. RESULTS: Ultrasound identified correctly 7 of 9 cases that were eventually positive for scaphoid fracture on plain x-ray. Ultrasound was read correctly as negative in 8 of 9 x-ray-negative cases; this was statistically significant. The 1 false-positive case had radioscaphoid arthrosis and radial wrist swelling. Sensitivity was 78% and specificity was 89%. The positive predictive value was 88% and negative predictive value was 80%. CONCLUSIONS: We recommend that high-frequency ultrasound be used to investigate occult suspected scaphoid fractures because of its ability to allow early diagnosis and to eliminate the need for a more invasive or expensive diagnostic test in most cases.

Neuropathology of the brain and spinal cord in human West Nile virus infection.

OBJECTIVE: To describe the histopathology of the brain and spinal cord in human West Nile virus (WNV) infection. MATERIALS AND METHODS: Single case report, including premortem clinical and laboratory findings, and autopsy. RESULTS: An 83-year-old female presented with acute confusion, high fevers, dysarthria and generalized subjective weakness, with decreased deep tendon reflexes and weakness on physical examination. Electromyography showed evidence of a sensorimotor axonal polyneuropathy of the right-sided extremities. She became ventilator-dependent and died after a 2-week ICU stay, following withdrawal of life support. WNV infection was confirmed premortem by detection of IgM antibodies from serum and CSF and postmortem by RT-PCR from brain tissue. Examination of the brain parenchyma showed scattered microglial aggregates accompanied by perivascular chronic inflammation. The leptomeninges showed focal lymphocytic infiltrates. Examination of the spinal cord showed lymphocytic infiltrates in nerve roots and within the cord proper, with focal microglial nodules and neuronophagia in the ventral horns. Special stains were negative for a demyelinating process. General autopsy revealed only emphysema and atelectasis. CONCLUSIONS: The findings in this case suggest direct viral infection of the spinal cord and nerve roots as the mechanism of the flaccid paralysis often observed in patients infected with WNV. Findings are reviewed in comparison with other reports of neuropathologic findings in human WNV infection.

Intracranial aneurysms associated with unsuspected aortic coarctation.

Intracranial aneurysms (IAs) are found more often in patients with aortic coarctation (AC) than in the general population and aneurysm rupture occurs much earlier in the lives of these patients when there is coexistent AC. The diagnosis of AC is frequently made only after a serious cerebrovascular complication has developed. The aim of this paper is to call attention to AC in patients presenting with aneurysmal subarachnoid hemorrhage. The literature is reviewed, the key clinical features are highlighted, and the proposed pathogenesis of this association is discussed. The authors present clinical information and imaging data obtained in three young patients with ruptured IAs that were associated with initially unnoticed AC. Abnormal results of cardiovascular examinations led the authors to consider an underlying AC, which was later confirmed by aortography. These aneurysms were successfully treated prior to correction of the ACs. The diagnosis of AC should be considered in adolescent and young adult patients presenting with IAs.

Normal and acutely torn posterior cruciate ligament of the knee at US evaluation: preliminary experience.

PURPOSE: To determine the ultrasonographic (US) findings of normal and acutely torn posterior cruciate ligament (PCL) of the knee and evaluate the usefulness of US in the injured PCL. MATERIALS AND METHODS: US images were obtained in 30 knees in 15 asymptomatic volunteers as a control group and in 35 patients clinically suspected of having an acute PCL injury. Only the distal half of the PCL was evaluated. Of the 35 patients, 28 had their PCL status confirmed: 13 had a normal PCL at magnetic resonance (MR) imaging plus clinical examination, and 15 had a torn PCL at either MR imaging and surgery or MR imaging and clinical follow-up. RESULTS: Normal PCLs were homogeneously hypoechoic, with a well-defined posterior border. Torn PCLs were heterogeneously hypoechoic (12 [80%] of 15 patients), with an indistinct posterior margin (11 [73%] of 15 patients). Torn PCLs were significantly thicker (range, 12.0-20.0 mm; mean, 15.6 mm +/- 2.5 [SD]; P <.01), as compared with normal PCLs in 13 patients (range, 3.8-5.8 mm; mean, 4.6 mm +/- 1.0; P <.01) and in the volunteers (range, 3.7-6.2 mm; mean, 4.5 mm +/- 1.2; P <.01). CONCLUSION: An acutely torn PCL thickens (>10 mm), loses its sharply defined posterior border, and has a heterogeneously hypoechoic appearance. US may be useful as a screening examination for patients suspected of having PCL injury and for deciding whether to perform more expensive MR imaging or surgical intervention.

Ultrasonography of the shoulder.

Musculoskeletal ultrasound (MSUS) is an important modality in evaluating shoulder disease. Following a baseline shoulder conventional radiographic examination, MSUS can be used to screen the painful shoulder. It is accurate in diagnosing full- and partial-thickness tears of the rotator cuff. Both types of tears can be further characterized by size, location, and extension. Postoperatively, the rotator cuff can also be evaluated for recurrent full-thickness tears. MSUS is the only modality that can visualize and characterize synovial disease, without radiographic contrast, and when necessary, US-guided aspiration and biopsy can be performed. Real-time scanning shows the actual motion of the shoulder and its parts. Multiple attempts can be made to achieve optimal images for accurate documentation. Accessibility to MSUS facilitates the rapid turnaround of patients. US imagers and bone radiologists would do well to use MSUS to help their referring physicians establish a quick and accurate diagnosis of shoulder disorders. This article presents a comprehensive, pictorial review of the technical aspects of shoulder sonography as well as major types of pathology that can be diagnosed with US.

Sonography of the knee, a pictorial review.

The use of ultrasound for evaluation of the knee is increasing. Although it cannot replace magnetic resonance imaging (MRI), which has been the modality of choice in conjunction with plain radiographs, ultrasound does have certain advantages in knee diagnosis. For example, in South Africa the cost of an ultrasound examination is approximately 10% of the cost of an MRI scan. Ultrasound is a very cost-effective alternative for imaging of the knee, providing the indications, advantages, and limitations are understood. Probably the greatest advantage of ultrasound, however, is for the detailed evaluation of the soft tissues within and surrounding the knee. These include ligamentous, tendinous, fibrous, fatty, synovial, and neurovascular structures. These tissues can be assessed for size, continuity, anatomic orientation, and echogenecity; furthermore, they can be readily compared contralaterally. Evaluation of intra-articular elements such as the menisci, cruciate ligaments, and articular cartilage is limited mainly by inaccessibility, which results from the small acoustic windows obtainable in most patients. This liberally illustrated article reviews ultrasound of the knee, including anatomy, ultrasound technique, and pathologic findings.