Prevalence of Sonographic Achilles Tendon, Patellar Tendon, and Plantar Fascia Abnormalities in Division I Collegiate Athletes From a Variety of Sports.

OBJECTIVE: This study aimed to determine the prevalence of ultrasound abnormalities in the Achilles tendon, patellar tendon, and plantar fascia among a large cohort of collegiate student-athletes. DESIGN: Observational cross-sectional study. SETTING: Three Division I institutions. PARTICIPANTS: 243 student-athletes participated in this study. Exclusion criteria included those younger than 18 years or who underwent prior surgery/amputation of structures, including anterior cruciate ligament (ACL) surgeries with patellar tendon grafts. INTERVENTIONS: Ultrasound examination of the Achilles tendon, patellar tendon, and plantar fascia of each leg was performed. An experienced sonographer reviewed each tendon video in a blinded manner, with a separate experienced sonographer separately reviewing to establish inter-rater reliability. MAIN OUTCOME MEASURES: The primary outcome measured was the presence of any sonographic abnormality including hypoechogenicity, thickening, or neovascularity. RESULTS: Ultrasound abnormalities were identified in 10.1%, 37.2%, and 3.9% of all Achilles tendons, patellar tendons, and plantar fasciae, respectively. Abnormalities were significantly associated with the presence of concurrent pain for all structures (P < 0.01). Specifically, athletes with sonographic abnormalities were approximately 4 times [relative risk (RR) = 4.25; 95% confidence interval (CI), 2.05-8.84], 6 times (RR = 5.69; 95% CI, 2.31-14.00), and 5 times (RR = 5.17; 95% CI, 1.76-15.25) more likely to self-report pain in the Achilles tendon, patellar tendon, and plantar fascia, respectively. CONCLUSIONS: This multi-institutional study completed at 3 Division I institutions is the largest study of its kind to identify the prevalence of sonographic abnormalities in the Achilles tendon, patellar tendon, and plantar fascia among collegiate student-athletes of various sports.

Identification of pre-race ultrasonographic abnormalities of the Achilles tendon and association with future injuries in runners.

OBJECTIVE: To determine if specific morphological changes in ultrasonographic images of Achilles tendons are associated with the development of pain in distance runners. METHODS: This study is a blinded, retrospective analysis of 276 Achilles tendon ultrasound images, which were used to determine if specific morphologic findings could positively or negatively predict future Achilles tendon pain development in distance runners. Pre-race ultrasound scans were performed on 138 asymptomatic half- and full marathon runners (276 tendons in total) who were followed for 12 months after their races. Specific patterns of morphologic abnormality were identified (location, size, and appearance of ultrasound abnormality within the tendon). Sonographic findings were blindly assessed by a medical student, a resident, and a physician who has significant sonographic imaging experience. These specific abnormalities were then compared to those who later did or did not develop tendon pain. RESULTS: Three findings were found to have significant odds of association with the development of pain: 1) focal deep midsubstance intratendinous hypoechogenicity, 2) focal superficial midsubstance intratendinous hypoechogenicity, and 3) linear hyperechogenicity extending into middle of tendon from calcaneus. CONCLUSION: These results suggest that the aforementioned specific morphologic abnormalities in the Achilles tendon may be associated with the future development of pain symptoms in distance runners in this cohort. Looking for these specific abnormalities may increase the specificity of identifying precursors to Achilles tendon pain development.

Sonographic peripheral nerve cross-sectional area in adults, excluding median and ulnar nerves: A systematic review and meta-analysis.

INTRODUCTION/AIMS: Although electromyography remains the "gold standard" for assessing and diagnosing peripheral nerve disorders, ultrasound has emerged as a useful adjunct, providing valuable anatomic information. The objective of this study was to conduct a systematic review and meta-analysis evaluating the normative sonographic values for adult peripheral nerve cross-sectional area (CSA). METHODS: Medline and Cochrane Library databases were systematically searched for healthy adult peripheral nerve CSA, excluding the median and ulnar nerves. Data were meta-analyzed, using a random-effects model, to calculate the mean nerve CSA and its 95% confidence interval (CI) for each nerve at a specific anatomical location (= group). RESULTS: Thirty groups were identified and meta-analyzed, which comprised 16 from the upper extremity and 15 from the lower extremity. The tibial nerve (n = 2916 nerves) was reported most commonly, followed by the common fibular nerve (n = 2580 nerves) and the radial nerve (n = 2326 nerves). Means and 95% confidence interval (CIs) of nerve CSA for the largest number of combined nerves were: radial nerve assessed at the spiral groove (n = 1810; mean, 5.14 mm2 ; 95% CI, 4.33 to 5.96); common fibular nerve assessed at the fibular head (n = 1460; mean, 10.18 mm2 ; 95% CI, 8.91 to 11.45); and common fibular nerve assessed at the popliteal fossa (n = 1120; mean, 12.90 mm2 ; 95% CI, 9.12 to 16.68). Publication bias was suspected, but its influence on the results was minimal. DISCUSSION: Two hundred thirty mean CSAs from 15 857 adult nerves are included in the meta-analysis. These are further categorized into 30 groups, based on anatomical location, providing a comprehensive reference for the clinician and researcher investigating adult peripheral nerve anatomy.

Sonographic Screening of Distance Runners for the Development of Future Achilles and Patellar Tendon Pain.

OBJECTIVE: The 2 primary aims of this study were to identify ultrasonographic tendon abnormalities in asymptomatic runners and to examine the likelihood of developing pain in runners with ultrasound abnormalities compared with those without abnormalities. DESIGN: Longitudinal, prospective cohort study. SETTING: 2019 Salt Lake City Marathon. PARTICIPANTS: Recreational half-marathon and full-marathon runners. ASSESSMENT OF RISK FACTORS: The Achilles and patellar tendons of asymptomatic runners were examined with ultrasound imaging before a running event. Runners were monitored for self-reported outcomes of pain in the examined tendons at 1, 3, 6, and 12 months after the event. MAIN OUTCOME MEASURES: Development of pain based on the presence of asymptomatic tendon abnormalities. RESULTS: One hundred thirty-eight runners (36.2 ± 12.0 years, 49.3% men, and 31.2% full-marathon runners) were included. Ultrasound abnormalities of the Achilles and patellar tendons were identified in 24.6% and 39.1% of the runners before the race, respectively. Ultrasound abnormalities were significantly associated with approximately a 3-fold increase [hazard ratio (HR) = 2.55, P = 0.004] in the hazard of developing pain in the Achilles tendon and patellar tendon (HR = 1.67, P = 0.042) over the year after the race. Positive and negative predictive values of developing pain over the year were 34.1% and 87.2%, respectively, for abnormal findings in the Achilles tendon, and 22.9% and 85.0%, respectively, for the patellar tendon. CONCLUSIONS: The presence of ultrasonographic abnormalities is associated with increased development of pain in the Achilles and patellar tendons within 1 year of a marathon or half marathon.

Thoracogenic spinal deformity: a rare cause of early-onset scoliosis.

OBJECTIVESurgery for severe congenital defects, such as congenital diaphragmatic hernia, congenital heart defects, and tracheoesophageal disorders, are life-saving treatments for many infants. However, the incidence of scoliosis following thoracoabdominal surgery has been reported to range from 8% to 50%. Little is known about severe scoliosis that occurs after chest wall procedures in infants. The authors sought to determine the prevalence of thoracogenic scoliosis, disease severity, and need for scoliosis surgery in patients who underwent chest wall procedures in early childhood.METHODSA multicenter database of patients with early-onset scoliosis was queried to identify patients with a history of thoracogenic or acquired iatrogenic scoliosis. Patients with significant congenital spine deformities were excluded. Forty-one patients (1.6%) were noted to have thoracogenic scoliosis. Of these patients, 14 patients were observed; 10 received casts and/or braces; and 17 underwent treatment with rib-based distraction rods, Shilla procedures, or spine-based growing rod devices. Radiographs, complications, and patient characteristics were reviewed.RESULTSThe mean age at scoliosis diagnosis for the 41 patients was 6.0 years. The mean time to follow-up was 2.9 years (4.5 years in the 17 surgical patients). The mean preoperative coronal Cobb angle in the surgical group was 65° and improved to 47° postoperatively (p = 0.01). The mean Cobb angle for the nonoperative group was 31° initially and 32° at follow-up (p = 0.44). Among the 17 patients undergoing surgery for scoliosis, there were 13 complications in 7 patients, including a brachial plexus palsy following rib-based distraction rod placement. This resolved with revision of the rib hooks. There were no known complications in the nonoperative cohort.CONCLUSIONSSevere scoliosis can develop after thoracoabdominal surgeries during infancy. Further work is needed to understand the pathogenesis of scoliosis in this population so as to implement measures for prevention and early diagnosis and to guide appropriate treatment.

Quantifying Effect of Onabotulinum Toxin A on Passive Muscle Stiffness in Children with Cerebral Palsy Using Ultrasound Shear Wave Elastography.

OBJECTIVE: A pilot study was conducted to longitudinally quantify effect of onabotulinum toxin A (BoNT-A) on passive muscle properties in children with cerebral palsy using ultrasound shear wave elastography. DESIGN: This was a prospective longitudinal cohort study. RESULTS: Between 1 and 3 mos post-BoNT-A, a significant improvement in the shear modulus of the lateral gastrocnemius was found at 10-degrees plantar flexion (PF) (-7.57 [-10.98, -5.07], P = 0.02) and 0-degrees PF (-14.74 [-18.21, -9.38], P = 0.03). There was a notable, but nonsignificant, difference in shear modulus at 20-degrees PF, 10-degrees PF, and 0-degrees PF between pre-BoNT-A and 1 mo post-BoNT-A. Pre-BoNT-A shear modulus was not significantly different from 3 mos post-BoNT-A at all foot positions. No significant differences in ankle passive range of motion or spasticity were found. CONCLUSION: Despite no significant change in ankle range of motion or spasticity, shear wave elastography was able to detect a difference in lateral gastrocnemius passive muscle properties in children with cerebral palsy after BoNT-A injections. The difference in passive muscle properties resolved by 3 mos post-BoNT-A.

Quantifying spasticity in individual muscles using shear wave elastography.

Spasticity is common following stroke; however, high subject variability and unreliable measurement techniques limit research and treatment advances. Our objective was to investigate the use of shear wave elastography (SWE) to characterize the spastic reflex in the biceps brachii during passive elbow extension in an individual with spasticity. The patient was a 42-year-old right-hand-dominant male with history of right middle cerebral artery-distribution ischemic infarction causing spastic left hemiparesis. We compared Fugl-Meyer scores (numerical evaluation of motor function, sensation, motion, and pain), Modified Ashworth scores (most commonly used clinical assessment of spasticity), and SWE measures of bilateral biceps brachii during passive elbow extension. We detected a catch that featured markedly increased stiffness of the brachialis muscle during several trials of the contralateral limb, especially at higher extension velocities. SWE was able to detect velocity-related increases in stiffness with extension of the contralateral limb, likely indicative of the spastic reflex. This study offers optimism that SWE can provide a rapid, real-time, quantitative technique that is readily accessible to clinicians for evaluating spasticity.

Quantifying passive muscle stiffness in children with and without cerebral palsy using ultrasound shear wave elastography.

AIM: The aim of this study was to compare passive muscle stiffness in children with cerebral palsy (CP) and children with typical development using a novel ultrasound technique: ultrasound shear wave elastography (SWE). METHOD: We conducted a prospective study of 13 children with CP (six females and seven males, median age 5y 1mo [interquartile range 4y 4mo-7y 8mo]) and 13 children with typical development (six females and seven males, median age 5y 3mo [interquartile range 4y 4mo-9y 4mo]). Demographic information and physical exam measurements were obtained in addition to shear modulus measurements (passive muscle stiffness) of the lateral gastrocnemius muscle at 20° plantar flexion, 10° plantar flexion, and 0° plantar flexion using SWE. RESULTS: Children with CP had significantly greater shear modulus measurements at all three foot positions (p<0.050). When the shear modulus values were normalized to the baseline value for each child, there was no significant difference between the two groups. INTERPRETATION: Passive muscle stiffness, measured without the influence of spasticity, is greater in children with CP than in children with typical development when a muscle is at slack and at stretch. When shear modulus was normalized, the results indicate that muscle in children in both groups responds similarly to passive stretch. Further work includes evaluating effect of botulinum toxin on passive muscle properties.

Feasibility and reliability of quantifying passive muscle stiffness in young children by using shear wave ultrasound elastography.

OBJECTIVES: The purpose of this study was to investigate the feasibility and reliability of passive muscle stiffness measurements in children by shear wave ultrasound elastography. METHODS: We conducted a prospective cross-sectional study quantifying the passive stiffness of bilateral lateral gastrocnemius muscles during passive stretching in 20 typically developing children (age range, 2.0-12.6 years). Data collected included passive stiffness of the lateral gastrocnemius muscle (shear modulus in kilopascals) at 4 positions of progressive passive foot dorsiflexion, demographic characteristics of the participants, and comparison of demographic characteristics with the shear modulus. RESULTS: Passive stiffness increased with increasing stretching (mean [SD] range of stiffness, 7.1 [2.0] to 36.2 [22.0] kPa). For all 4 foot positions, no significant difference was found between right and left legs (range, P = .42 to P = .98) or between the sexes (range, P = .28 to P > .99). No correlation of passive muscle stiffness with age, body mass index, or ankle range of motion was found. The reliability of measurements was good to excellent (mean [95% confidence interval] range of reliability, 0.67 [0.44-0.83] to 0.80 [0.63-0.90]). CONCLUSIONS: Measurements of passive stiffness of the lateral gastrocnemius muscle are feasible and reliable in children as young as 2 years. Because this study found no significant difference between sex and the side tested in this age group, future studies involving children of this age range may not need to be stratified on the basis of these parameters. Defining normal passive muscle stiffness in children is critical for identifying and understanding the implications of abnormal passive muscle stiffness in children with neuromuscular disorders.

Iliac bone grafting of the intact glenoid improves shoulder stability with optimal graft positioning.

BACKGROUND: Bone grafting procedures are increasingly popular for the treatment of anterior shoulder instability. In patients with a high risk of recurrence, open coracoid transplantation is preferred but can be technically demanding. Free bone graft glenoid augmentation may be an alternative strategy for high-risk patients without significant glenoid bone loss. This biomechanical cadaveric study assessed the stabilizing effect of free iliac crest bone grafting of the intact glenoid and the importance of sagittal graft position. METHODS: Eight fresh frozen cadaveric shoulders were tested. The bone graft was fixed on the glenoid neck at 3 sagittal positions (50%, 75%, and 100% below the glenoid equator). Displacement and reaction force were monitored with a custom device while translating the humeral head over the glenoid surface in both anterior and anteroinferior direction. RESULTS: Peak force (PF) increased significantly from the standard labral repair to the grafted conditions in both anterior (14.7 ± 5.5 N vs 27.3 ± 6.9 N) and anteroinferior translation (22.0 ± 5.3 N vs 29.3 ± 6.9 N). PF was significantly higher for the grafts at the 50% and 75% positions compared with the grafts 100% below the equator with anterior translation. Anteroinferior translation resulted in significantly higher values for the 100% and 75% positions compared with the 50% position. CONCLUSIONS: This biomechanical study confirms improved anterior glenohumeral stability after iliac crest bone graft augmentation of the anterior glenoid. The results also demonstrate the importance of bone graft position in the sagittal plane, with the ideal position determined by the direction of dislocation.

Shear wave elastography of passive skeletal muscle stiffness: influences of sex and age throughout adulthood.

BACKGROUND: Numerous structural and compositional changes - related not only to age, but also activity level and sex - may affect skeletal muscle stiffness across the adult age-span. Measurement techniques available thus far have largely limited passive stiffness evaluations to those of entire joints and muscle-tendon units. Shear wave elastography is an increasingly popular ultrasound technique for evaluating the mechanical properties of skeletal muscle tissue. The purpose of this study was to quantify the passive stiffness, or shear modulus, of the biceps brachii throughout adulthood in flexed and extended elbow positions. We hypothesized that shear modulus would be higher in males relative to females, and with advanced age in both sexes. METHODS: Shear wave elastography quantified biceps brachii stiffness at 90° elbow flexion and full extension in a large sample of adults between 21 and 94 years old (n=133; 47 males). FINDINGS: Regression analysis found sex and age were significant parameters for older adults (>60 years) in full extension. As expected, shear modulus values increased with advancing age; however, shear modulus values for females tended to be higher than those for males. INTERPRETATION: This study begins to establish normative trends for skeletal muscle shear modulus throughout adulthood. Specifically, this work establishes for the first time that the higher passive joint torque often found in males relative to females likely relates to parameters other than muscle shear modulus. Indeed, perhaps increases in skeletal muscle passive stiffness, though potentially altering the length-tension curve, serve a protective role - maintaining the tendon-muscle-tendon length-tension curve within a functional range.

Ultrasound elastography: the new frontier in direct measurement of muscle stiffness.

The use of brightness-mode ultrasound and Doppler ultrasound in physical medicine and rehabilitation has increased dramatically. The continuing evolution of ultrasound technology has also produced ultrasound elastography, a cutting-edge technology that can directly measure the mechanical properties of tissue, including muscle stiffness. Its real-time and direct measurements of muscle stiffness can aid the diagnosis and rehabilitation of acute musculoskeletal injuries and chronic myofascial pain. It can also help monitor outcomes of interventions affecting muscle in neuromuscular and musculoskeletal diseases, and it can better inform the functional prognosis. This technology has implications for even broader use of ultrasound in physical medicine and rehabilitation practice, but more knowledge about its uses and limitations is essential to its appropriate clinical implementation. In this review, we describe different ultrasound elastography techniques for studying muscle stiffness, including strain elastography, acoustic radiation force impulse imaging, and shear-wave elastography. We discuss the basic principles of these techniques, including the strengths and limitations of their measurement capabilities. We review the current muscle research, discuss physiatric clinical applications of these techniques, and note directions for future research.

Validation of shear wave elastography in skeletal muscle.

Skeletal muscle is a very dynamic tissue, thus accurate quantification of skeletal muscle stiffness throughout its functional range is crucial to improve the physical functioning and independence following pathology. Shear wave elastography (SWE) is an ultrasound-based technique that characterizes tissue mechanical properties based on the propagation of remotely induced shear waves. The objective of this study is to validate SWE throughout the functional range of motion of skeletal muscle for three ultrasound transducer orientations. We hypothesized that combining traditional materials testing (MTS) techniques with SWE measurements will show increased stiffness measures with increasing tensile load, and will correlate well with each other for trials in which the transducer is parallel to underlying muscle fibers. To evaluate this hypothesis, we monitored the deformation throughout tensile loading of four porcine brachialis whole-muscle tissue specimens, while simultaneously making SWE measurements of the same specimen. We used regression to examine the correlation between Young's modulus from MTS and shear modulus from SWE for each of the transducer orientations. We applied a generalized linear model to account for repeated testing. Model parameters were estimated via generalized estimating equations. The regression coefficient was 0.1944, with a 95% confidence interval of (0.1463-0.2425) for parallel transducer trials. Shear waves did not propagate well for both the 45° and perpendicular transducer orientations. Both parallel SWE and MTS showed increased stiffness with increasing tensile load. This study provides the necessary first step for additional studies that can evaluate the distribution of stiffness throughout muscle.