Comparison of Magnetic Resonance Imaging and Ultrasound Evaluations of Zone II Partial Flexor Tendon Lacerations: A Cadaveric Study.

OBJECTIVES: Surgical intervention for zone II high-grade partial flexor tendon lacerations is often required when more than half of the tendon width is torn. Reliable noninvasive tests are critical for optimizing clinical decision making. Our team previously investigated the use of ultrasound (US) for identification of high-grade zone II flexor digitorum profundus lacerations. In this study, we compared magnetic resonance imaging (MRI) to US for the evaluation of high-grade partial flexor tendon lacerations in cadaveric specimens. METHODS: Dissection of 32 digits in 8 fresh-frozen upper extremity cadaveric specimens was performed. The flexor digitorum profundus tendons were randomized into 3 groups: intact, low-grade laceration, and high-grade laceration. A dynamic US examination was performed by a blinded musculoskeletal radiologist. The same specimens underwent hand coil MRI, which was read by the same blinded radiologist. Magnetic resonance imaging test performance metrics were calculated and compared to those computed for the US evaluation. RESULTS: For US evaluation of high-grade lacerations, the sensitivity and specificity were 0.5 and 1.0, with positive likelihood ratio (LR+) and negative likelihood ratio (LR-) values of ∞ and 0.50, respectively. The sensitivity and specificity for MRI evaluation were 0.2 and 1.0, with LR+ and LR- values of ∞ and 0.80. CONCLUSIONS: Both US and MRI are adequate at determining the presence of a high-grade laceration. Magnetic resonance imaging was more specific than US in identification of high-grade partial flexor tendon lacerations. Although less specific, US is a reasonable and less-expensive alternative to MRI when evaluating for clinically significant high-grade partial flexor tendon lacerations.

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.

Ultrasonographic Evaluation of Zone II Partial Flexor Tendon Lacerations of the Fingers: A Cadaveric Study.

OBJECTIVES: Accurate assessment of zone II partial flexor tendon lacerations in the finger is clinically important. Surgical repair is recommended for lacerations of greater than 50% to 60%. Our goal was to evaluate ultrasonographic test characteristics and accuracy in identifying partial flexor tendon lacerations in a cadaveric model. METHODS: From fresh-frozen above-elbow human cadaveric specimens, 32 flexor digitorum profundus tendons were randomly selected to remain intact or receive low- or high-grade lacerations involving 10% to 40% and 60% to 90% of the radioulnar width within Verdan Zone II, respectively. Static and dynamic ultrasonography using a linear array 14-MHz transducer was performed by a blinded musculoskeletal radiologist. Sensitivities, specificities, and other standard test performance metrics were calculated. Actual and measured percentages of tendon laceration were compared by the paired t test. RESULTS: After randomization, 24 tendons were lacerated (12 low- and 12 high-grade), whereas 8 remained intact. The sensitivity and specificity in detecting the presence versus absence of a partial laceration were 0.54 and 0.75, respectively, with positive and negative likelihood ratio values of 2.17 and 0.61. For low-grade lacerations, the sensitivity and specificity were 0.25 and 0.85, compared to 0.83 and 0.85 for high-grade lacerations. Ultrasonography underestimated the percentage of tendon involvement by a mean of 18.1% for the study population as a whole (95% confidence interval, 9.0% to 27.2%; P < .001) but accurately determined the extent for correctly diagnosed high-grade lacerations (-6.7%; 95% confidence interval, -18.7% to 5.2%; P = .22). CONCLUSIONS: Ultrasonography was useful in identifying and characterizing clinically relevant high-grade zone II partial flexor digitorum profundus lacerations in a cadaveric model.

Lesion size measurement in femoral head necrosis.

BACKGROUND: Management of patients with early stages of osteonecrosis of the femoral head remains controversial. Uniform use of an effective method of evaluation and classification, including both stage and lesion size, would allow for comparison and would significantly improve treatment of patients. There is no consensus on how best to determine lesion size. The purpose of this study was to evaluate and compare accuracy and ease of use of different techniques for determining the size of femoral head lesions. METHODS: Twenty-five hips with stages I or II osteonecrosis were evaluated with radiographs and MRI. 3-D MRI measurements of lesion size were used as the standard against which to compare visual estimates and angular measurements: necrotic angle of Kerboul, index of necrosis, and adjusted index of necrosis. RESULTS: 3-D measurements (necrotic volume) showed regular progression from 2.2 to 59.2% of the femoral head. There was a rough correlation with angular measurements; index of necrosis was closer than the necrotic angle. Visual estimates from serial MRI images were as accurate as angular measurements. CONCLUSIONS: Simple visual estimates of lesion size from serial MRI images are reasonably accurate and are satisfactory for clinical use. Angular measurements provide some indication of prognosis and treatment; however, they have limited accuracy, with considerable variability between techniques. 3-D MRI volumetric measurements are the most accurate. Using current techniques and software, they are easier to use, requiring similar time and effort to angular measurements. They should be considered for clinical research and publications when the most accurate measurements are required.

Ultrasound of the Knee: Common Pathology Excluding Extensor Mechanism.

Ultrasound can be used to diagnose many types of pathology and guide various diagnostic or therapeutic procedures. The most common applications for musculoskeletal ultrasound of the knee include evaluation of the joint recesses, the extensor mechanism, and bursae including Baker's cyst. However, a role exists for ultrasound in the evaluation of cartilage, other tendons, ligaments, peripheral nerves, osseous structures, and vasculature. This article reviews common pathologies of these structures as seen with ultrasound. In addition, various ultrasound-guided procedures pertaining to these pathologies are introduced. The importance of a comprehensive evaluation is also emphasized as a method to maximize information gained from the ultrasound examination.

Ultrasound-Guided Therapy for Knee and Foot Ganglion Cysts.

The present study evaluated the effectiveness of ultrasound-guided aspiration/injection of ganglion cysts in the lower extremities (knee and foot) that required referral to the radiology department for precise localization. The present study is the first series to describe such results. The study population consisted of 15 patients who had undergone treatment from April 2012 to January 2015. Follow-up was by telephone survey, which was performed at a mean of 15 ± 6 months after treatment. Almost 90% of patients experienced immediate improvement in symptoms (mostly pain), and 77% of these patients had not experienced a recurrence of symptoms at a mean follow-up time of 14 ± 6 months. In conclusion, ultrasound-guided therapy is a safe and potentially effective treatment for most cases of symptomatic lower extremity ganglion cysts.

Ultrasound of the Groin: Techniques, Pathology, and Pitfalls.

OBJECTIVE: In a patient with symptoms referable to the groin, there can be a number of causes to consider and at times the cause of the symptoms is multifactorial. Although ultrasound can be effective in the evaluation of the groin, the depth and complexity of the anatomy can be problematic. A protocol-driven approach for ultrasound evaluation of the groin will help to ensure an accurate and comprehensive evaluation. This article summarizes the ultrasound technique and protocol for evaluation of the groin to include evaluation of the hip joint, anterior hip musculature, the iliopsoas bursa, the inguinal lymph nodes, the pubic symphyseal region, and the inguinal region for hernias. Common pathologic conditions and pitfalls related to ultrasound evaluation of the groin will be reviewed. CONCLUSION: There are many potential pathologic conditions in a patient with groin symptoms. Because symptoms may be multifactorial and history may be ambiguous or misleading, a protocol-driven evaluation with ultrasound is recommended. The hip joint is evaluated for effusion, synovitis, and labral abnormalities. The muscles and tendons, including the common aponeurosis at the pubic symphysis, are evaluated for tendinosis and tears. Dynamic evaluation should be considered to assess for snapping hip syndrome. Iliopsoas bursal distention and lymph node enlargement are other considerations. Last, inguinal region hernias must be evaluated during the Valsalva maneuver and documented in two orthogonal planes to avoid several important diagnostic pitfalls.

Magnetic resonance imaging of painful metal-on-metal total hip replacement.

Consecutive patients that had primary metal-on-metal (MoM) or metal-on-polyethylene (MoP) hip arthroplasty were prospectively enrolled to this study. All operated hips were evaluated with MRI by one radiologist who was blinded to the radiographic findings and clinical symptoms. Three groups of patients were formed: (1) thirteen MoM THRs in 13 patients with groin pain (Group 1), (2) ten MoM THRs in 10 patients with no pain (Group 2), (3) five MoP THRs in 4 patients without pain (control group). Abnormal MRI findings were distributed in all groups in a balanced way, irrespective of the patients' symptoms, prostheses, or metal ion levels. Two patients from Group 1 and one patient of Group 3 (control group) were diagnosed with a large periprosthetic mass (pseudotumor).

Sonography as a tool for identifying engaging Hill-Sachs lesions: preliminary experience.

Engaging Hill-Sachs lesions can be a factor predictive of recurrent anterior shoulder instability, yet no method has been recognized as an effective means to predict engagement. We evaluated the ability of sonography to identify engaging Hill-Sachs lesions by using a transaxillary approach and dynamic scanning. In patients with engaging lesions, there was an abrupt change in the contour of the humeral head when the shoulder was in 90° of abduction and 90° of external rotation. Sonography therefore has the potential to be a useful preoperative tool in determining which patients may benefit from a surgical repair that also addresses Hill-Sachs lesions.

Subperiosteal hematoma of the iliac bone: imaging features of acute and chronic stages with emphasis on pathophysiology.

PURPOSE: The goal of this work is to describe the radiological appearance and clinical presentation of subperiosteal iliac hematoma and present a review of the literature. MATERIALS AND METHODS: We retrospectively reviewed the radiological and clinical files of 19 patients (age range: 12-75; mean: 47) who presented with acute or chronic subperiosteal iliac hematomas. Imaging findings and relevant clinical information were recorded. A thorough literature search was performed to find additional cases of this rare condition. RESULTS: Three young patients presented with acute subperiosteal iliac hematoma following a fall. Clinical presentation was characterized by pain and gait disturbance presumed to result from crural nerve compression. Unilateral or bilateral lenticular hematomas deep in the iliacus muscle were demonstrated by CT for all patients while MRI was also available for two of them. In 16 asymptomatic patients, chronic ossified subperiosteal iliac hematomas were incidentally detected by CT. Progressive ossification of acute hematoma was demonstrated at follow-up in two patients. CONCLUSIONS: Subperiosteal iliac hematoma is rare but has typical imaging findings that may present acutely in adolescents or chronically in asymptomatic adults.

"Tenomalacia": a new sonographic sign of tendinopathy?

The purpose of this study was to assess tendon compressibility with sonography in extensor tendinopathy and in asymptomatic extensor tendons of the elbow. Sonography of both elbows was performed in eight patients with a clinical diagnosis of unilateral lateral epicondylitis. Tendons were assessed for compressibility by measuring their thickness before and after compression with the transducer. The same manoeuvre was performed while tendon vascularity was assessed with colour Doppler. All eight cases showed increased compressibility of the common extensor tendon on the painful side compared to the asymptomatic side, as well as increased vascularity with compressible vessels on colour Doppler. Other signs of tendinopathy were hypoechogenicity (n = 8), loss of fibrillar pattern (n = 8), intratendinous calcifications (n = 1), partial tears (n = 3), and enthesophytes (n = 5). Increased tendon compressibility indicative of tendon softening or "tenomalacia" is a new sonographic sign of common extensor tendinopathy.

Ultrasound-Guided Dry Needling of the Healthy Rat Supraspinatus Tendon Elicits Early Healing Without Causing Permanent Damage.

Overuse-induced tendinopathy is highly prevalent in the general population. Percutaneous fenestration, or dry needling, techniques have been increasing in popularity, but despite their current use, there are no controlled laboratory studies to provide fundamental support for this practice. The objective of this study was to establish a model for percutaneous needling of the rat supraspinatus tendon using ultrasound guidance and to evaluate the biological response of needling healthy tendon. A total of 44 male Sprague-Dawley rats (477 ± 39 g) were used to evaluate the effect of dry needling on healthy supraspinatus tendon properties. Ten rats were reserved as un-needled control animals, and the remaining animals underwent either mild or moderate bilateral needling protocols and were sacrificed at 1 or 6 weeks post-needling (n = 8-10/group). Color Doppler ultrasound imaging was performed to analyze blood flow within the tendon. Histological and immunohistochemical analyses were used to determine cellular, inflammatory, and extracellular matrix properties of the tissue. Finally, quasi-static tensile mechanical analysis was performed to obtain viscoelastic, structural, and material properties to evaluate the tendon healing outcome. Data were tested for normality, and then two-way analysis of variance tests were performed followed by post hoc tests for multiple comparisons. Both the mild and moderate needling groups caused a transient healing response at early time points as shown by a statistically significant (p < 0.05) reduction in mechanical properties, and increase in blood flow, inflammation, and production of collagen III and glycosaminoglycans as compared to the control. Furthermore, mild needling properties returned to or exceeded pre-needling values at the 6-week time point. Clinical significance: Needling the rat supraspinatus tendon is a feasible technique that causes a transient healing response followed by a return to, or improvement of, normal tendon properties, indicating potential applicability in understanding the effects of current practices utilizing dry needling of tendons in humans. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2035-2042, 2019.

Atrophy and fatty infiltration of the supraspinatus muscle: sonography versus MRI.

OBJECTIVE: The objective of our study was to compare sonography with MRI for the evaluation of supraspinatus muscle atrophy and fatty infiltration. SUBJECTS AND METHODS: Forty-five shoulders in 39 patients who had undergone shoulder MRI for the assessment of rotator cuff disease were evaluated blindly with sonography. Supraspinatus muscle atrophy was quantitatively assessed by calculating the occupation ratio (cross-sectional surface area of the supraspinatus muscle belly divided by that of its fossa). This was done by reproducing on sonography the equivalent of the "Y" view on MRI. Fatty infiltration was assessed by evaluating supraspinatus muscle echogenicity compared with that of the trapezius muscle and pennate pattern. The occupation ratio and fatty infiltration of the supraspinatus muscle on sonography were compared with these findings on MRI. RESULTS: Occupation ratios calculated on sonography images ranged from 0.07 (severe atrophy) to 0.81 (normal) and correlated with the ratios calculated on MRI (R = 0.90; 95% CI, 0.83-0.95). All 20 shoulders with no fatty infiltration on MRI had normal echogenicity and a pennate pattern on sonography. Eight of the 10 shoulders with mild fatty infiltration on MRI had an effaced pennate pattern and mild hyperechogenicity on sonography. In 13 of the 15 shoulders with moderate to severe fatty infiltration on MRI, the pennate pattern was absent and marked hyperechogenicity was present on sonography. CONCLUSION: Our study suggests that there is a good correlation between sonography and MRI for the assessment of supraspinatus muscle atrophy and fatty infiltration.

Quantitative peripheral muscle ultrasound in sepsis: Muscle area superior to thickness.

PURPOSE: The objective of this study is to describe the relationship between two quantitative muscle ultrasound measures, the rectus femoris cross-sectional area (RF-CSA) and quadriceps muscle thickness, with volitional measures of strength and function in critically ill patients with sepsis. MATERIALS AND METHODS: We performed a prospective study of patients admitted to a medical ICU with sepsis and shock or respiratory failure. We examined the association of two ultrasound measurements - the RF-CSA and quadriceps muscle thickness - with strength and function at day 7. Strength was determined using the Medical Research Council Score and function using Physical Function in the ICU Test, scored. RESULTS: Twenty-nine patients were enrolled; 19 patients had outcome testing performed. Over 7days, RF-CSA and thickness decreased by an average of 23.2% and 17.9%, respectively. The rate of change per day of RF-CSA displayed a moderate correlation with strength (ρ 0.51, p-value 0.03) on day 7. Baseline and day 7 RF-CSA did not show a significant correlation with either outcome. Quadriceps muscle thickness did not significantly correlate with either outcome. CONCLUSIONS: Muscle atrophy as detected by the rate of change in RF-CSA moderately correlated with strength one week after sepsis admission.

Musculoskeletal sonography: a dynamic tool for usual and unusual disorders.

OBJECTIVE: The purpose of this study is to illustrate a wide variety of musculoskeletal disorders that can be diagnosed with dynamic sonography. CONCLUSION: Dynamic sonography is a useful tool for the evaluation of a variety of musculoskeletal disorders. Many of these disorders cannot be diagnosed by any other imaging method.

Correlation Between Femoroacetabular Impingement and Hamstring Tendon Pathology on Magnetic Resonance Imaging and Arthrography.

Femoroacetabular impingement (FAI) is an abnormality of the femoral head or acetabulum that leads to an increased incidence of cartilaginous injury in the hip. Femoroacetabular impingement has been associated with several structural abnormalities, including osteitis pubis and hip flexor dysfunction. The authors propose that, additionally, FAI may lead to increased damage of the hamstring tendon due to the additional stress placed on the tendon from the limited range of motion of the hip. The authors conducted a retrospective matched-pair study with the magnetic resonance imaging and magnetic resonance arthrography images of 40 patients' hamstrings with FAI and 45 age-matched controls. Images were identified and reviewed by 2 musculoskeletal radiologists for various signs of hamstring tendon pathology. Fisher's exact test and an odds ratio were used to assess for a difference in the occurrence of hamstring tendon pathology in the FAI patient cohort compared with the age-matched controls. The results showed a statistically significant increase in the occurrence of hamstring tendon pathology in the FAI patient cohort compared with the age-matched controls (P<.001). The odds ratio for hamstring tendon pathology in a subject with confirmed FAI vs control subjects was 8.30 (95% confidence interval, 3.20-21.5), indicating a significant increase in the risk of developing hamstring tendon pathology among patients with FAI (P<.001). This study suggests that there may be an increased occurrence of hamstring tendon pathology in patients with FAI. The kinetic chain of motion, where restricted rotation at the hip joint increases the stress on the hamstring tendons, leading to damage, may explain this increase. [Orthopedics. 2017; 40(6):e1086-e1091.].

Ultrasonography Detects Ulnar Nerve Dislocation Despite Normal Electrophysiology and Magnetic Resonance Imaging.

BACKGROUND: Dislocation of the ulnar nerve (UN) occurs in a subset of patients with ulnar neuropathy. Electrodiagnostic and magnetic resonance imaging (MRI) studies are performed to support the clinical diagnosis. We report the case of a patient with ulnar neuropathy with normal electrodiagnostic and MRI studies but with ultrasonography (US) showing UN dislocation, which prompted successful treatment by UN submuscular transposition. CASE DESCRIPTION: A healthy 15-year-old female softball player presented with right medial elbow pain and paresthesias of the fourth and fifth digits. She had 4+/5 strength in the right hand intrinsic muscles and a Tinel sign at the right elbow. A snap was palpated at the elbow upon flexion. MRI showed mild common flexor tendonitis, and electrodiagnostic studies showed normal motor responses and no conduction block at the elbow. High-resolution US showed dislocation of the UN over the medial epicondyle. UN dislocation was confirmed intraoperatively, and, after UN submuscular transposition, the patient reported complete resolution of her preoperative symptoms at 6-week follow-up and continued resolution at 1 year. CONCLUSIONS: Normal findings on electrodiagnostic or MRI studies should not immediately dissuade surgeons from operating on a symptomatic patient with a clinical examination supporting ulnar neuropathy and with US evidence of UN dislocation, because such a patient may experience postoperative symptom relief. Furthermore, the dynamic capability of US imaging complements data obtained from electrodiagnostic and MRI studies, especially when these tests are normal, and it should be considered by clinicians when evaluating patients with medial elbow pain or signs of ulnar neuropathy.

Correlation Between Cam-Type Femoroacetabular Impingement and Radiographic Osteitis Pubis.

A mechanistic link has been suggested between cam-type femoroacetabular impingement and increased stress on the symphysis pubis. This retrospective study was conducted to determine whether there is an increased prevalence of osteitis pubis, as evidenced by imaging, in patients with femoroacetabular impingement compared with age-matched control subjects. Search of a radiologic database of a large academic health institution for all patients with cam-type femoroacetabular impingement diagnosed by magnetic resonance imaging or magnetic resonance arthrogram between January 2000 and October 2013 identified 46 cases. Two radiologists reviewed these cases independently and confirmed the presence of femoroacetabular impingement based on alpha angle and other characteristics of cam morphology. The imaging studies were further evaluated for characteristics of osteitis pubis, with severity graded from minimal to severe on a 4-point Likert scale. A control group composed of age-matched subjects without diagnosed femoroacetabular impingement was also evaluated for osteitis pubis. A statistically significant increase in the prevalence of osteitis pubis was found in patients with femoroacetabular impingement compared with age-matched control subjects, with a prevalence of 43.48% in the femoroacetabular impingement group compared with 12.77% in the control group (P=.0012). On the 4-point Likert scale, the average severity of osteitis pubis in the group with femoroacetabular impingement was 1.5 (minimal to mild) compared with 0.53 (no osteitis pubis to minimal findings) in the control population. This significant increase in osteitis pubis in patients with femoroacetabular impingement supports the clinical link between these 2 processes. [Orthopedics. 2016; 39(3):e417-e422.].

Ultrasonographic Evaluation of Peripheral Nerves.

There are a variety of imaging modalities for evaluation of peripheral nerves. Of these, ultrasonography (US) is often underused. There are several advantages of this imaging modality, including its cost-effectiveness, time-efficient assessment of long segments of peripheral nerves, ability to perform dynamic maneuvers, lack of contraindications, portability, and noninvasiveness. It can provide diagnostic information that cannot be obtained by electrophysiologic or, in some cases, magnetic resonance imaging studies. Ideally, the neurosurgeon can use US as a diagnostic adjunct in the preoperative assessment of a patient with traumatic, neoplastic, infective, or compressive nerve injury. Perhaps its most unique use is in intraoperative surgical planning. In this article, a brief description of normal US nerve anatomy is presented followed by a description of the US appearance of peripheral nerve disease caused by trauma, tumor, infection, and entrapment.