Ultrasound assessment of tendons in asymptomatic volunteers: a study of reproducibility

A New Quantitative Tool for the Ultrasonographic Assessment of Tendons: A Reliability and Validity Study on the Patellar Tendon

Ultrasound is widely used for tendon assessment due to its safety, affordability, and portability, but its subjective nature poses challenges. This study aimed to develop a new quantitative analysis tool based on artificial intelligence to identify statistical patterns of healthy and pathological tendons. Furthermore, we aimed to validate this new tool by comparing it to experts' subjective assessments. A pilot database including healthy controls and patients with patellar tendinopathy was constructed, involving 14 participants with asymptomatic (n = 7) and symptomatic (n = 7) patellar tendons. Ultrasonographic images were assessed twice, utilizing both the new quantitative tool and the subjective scoring method applied by an expert across five regions of interest. The database contained 61 variables per image. The robustness of the clinical and quantitative assessments was tested via reliability analyses. Lastly, the prediction accuracy of the quantitative features was tested via cross-validated generalized linear mixed-effects logistic regressions. These analyses showed high reliability for quantitative variables related to "Bone" and "Quality", with ICCs above 0.75. The ICCs for "Edges" and "Thickness" varied but mostly exceeded 0.75. The results of this study show that certain quantitative variables are capable of predicting an expert's subjective assessment with generally high cross-validated AUC scores. A new quantitative tool for the ultrasonographic assessment of the tendon was designed. This system is shown to be a reliable and valid method for evaluating the patellar tendon structure.

Multispectral Optoacoustic Tomography Enables In Vivo Anatomical and Functional Assessment of Human Tendons

Tendon injuries resulting from accidents and aging are increasing globally. However, key tendon functional parameters such as microvascularity and oxygen perfusion remain inaccessible via the currently available clinical diagnostic tools, resulting in disagreements on optimal treatment options. Here, a new noninvasive method for anatomical and functional characterization of human tendons based on multispectral optoacoustic tomography (MSOT) is reported. Healthy subjects are investigated using a hand-held scanner delivering real-time volumetric images. Tendons in the wrist, ankle, and lower leg are imaged in the near-infrared optical spectrum to utilize endogenous contrast from Type I collagen. Morphology of the flexor carpi ulnaris, carpi radialis, palmaris longus, and Achilles tendons are reconstructed in full. The functional roles of the flexor digitorium longus, hallicus longus, and the tibialis posterior tendons have been visualized by dynamic tracking during toe extension-flexion motion. Furthermore, major vessels and microvasculature near the Achilles tendon are localized, and the global increase in oxygen saturation in response to targeted exercise is confirmed by perfusion studies. MSOT is shown to be a versatile tool capable of anatomical and functional tendon assessments. Future studies including abnormal subjects can validate the method as a viable noninvasive clinical tool for tendinopathy management and healing monitoring.

Fatigue-induced Alterations of the Patellar Tendon in Elite Sprint Track Cyclists

This study aims to investigate morphological and mechanical properties and echogenicity of the patellar tendon (PT) after acute fatigue-induced alterations in sprint track cyclists. Fourteen elite track cyclists participated in this study. The exercise protocol consisted of three maximal start accelerations (over a distance of 62.5 m), one maximal start acceleration (at both 125 m and 250 m), and sprints from the standing start. Immediately after testing all measurements, PT stiffness and thickness were set at 5-10-15-20 mm distal from the apex of the patella and 5-10 mm proximal to the tibial tuberosity. CSA was set at proximal, middle, and distal, while echogenicity was at proximal and distal points. The results showed significant increases in PT stiffness at all reference points after start acceleration (p<0.001). PT thickness showed similar results for stiffness, except for location placed at TT-5 (p<0.001). CSA increased significantly in proximal, middle, and distal regions (p<0.001), while echogenicity of the tendon increased in proximal and distal regions (p<0.001) after start acceleration. Regional-dependent alterations of PT thickness and stiffness may be related to anatomical and physiological mechanisms due to acute isometric contraction in the initial phase of standing start. Tendon echogenicity might be also useful in monitoring tendon mechanical properties and defining acute fatigue-induced changes.

Reliability of a special device for measuring the cross-sectional area of the patellar tendon by ultrasonography

The objective of this study was to evaluate the intra- and inter-rater reliability and agreement between conditions with and without a special device (SD) in the evaluation of the patellar tendon (PT) cross-sectional area (CSA). Forty trained adult volunteers participated in the study. With the knee positioned at 90°, the ultrasound probe was placed in the transverse plane at 25, 50, and 75% of the PT length. Two raters and one analyzer obtained the images. We use a two-way ANOVA with a significance level of α = 0.05. No significant differences were found between raters or conditions. Intra-rater reliability ranged from moderate to good. Inter-rater reliability without the SD ranged from low to good, improving from moderate to good when the SD was used. Evaluation of the PT ends showed a lower coefficient of variation with the SD. We observed a moderate correlation at the ends and a strong correlation in the middle between conditions. The mean difference in the three positions is small (~ 0.013 cm2/ ~ 1.7%) with an upper limit of 43.2% and a lower limit of 32.5%. Therefore, we conclude that the use of the SD can be employed for evaluating the PT ends, while for the central region, it becomes optional.

A New Test for Achilles Tendinopathy Based on Kager's Fat Pad Clinical Assessment Predictive Values

Background This study aimed to check the diagnostic accuracy of a new test to identify Achilles tendinopathy.

STUDY DESIGN

Observational study.

METHODS

Seventy patients recruited from a private medical centre met the diagnostic criteria for unilateral Achilles tendinopathy (age, 45.1 ± 12.7 years; weight, 75.00 ± 10 kg; height, 1.75 ± 0.1 m) and were tested based on both Achilles tendons. Seventy patients with a unilateral Achilles tendinopathy ultrasound diagnosis were tested using David's test.

RESULTS

Most (86%) subjects demonstrated Kager's fat pad asymmetry in relation to the Achilles tendon in the complete passive dorsiflexion in the prone position (David's sign). No healthy tendons had David's sign.

CONCLUSIONS

The presence of asymmetry in Kager's fat pad in relation to the Achilles tendon during complete passive dorsiflexion is strongly indicative of ultrasound-diagnosed tendinopathy. David's test demonstrated a sensitivity of 85.71% (95% CI, 77.51% to 93.91%) and a specificity of 100% (95% CI, 100% to 100%), while noting the lack of blinding of the assessors and the uncertainty of the diagnostic measures (95% CI). Asymmetry of the fat pad could potentially serve as a characteristic marker for patients with Achilles tendinopathy.

Effect of Patient's Positioning on the Grade of Tendinosis and Visible Range of Infraspinatus Tendon on Ultrasound

Purpose

To investigate the effect of patient positioning on tendinosis grade, visible range, and infraspinatus tendon (IST) thickness, and to determine the feasibility of internal rotation (IR) position to assess IST on ultrasound (US).

Materials and Methods

This study included 52 shoulders of 48 subjects who were evaluated for IST in three different positions: neutral position (N), IR, and position with the ipsilateral hand on the contralateral shoulder (HC). Two radiologists retrospectively graded IST tendinosis from grade 0 to grade 3 and the visible range from grade 1 to grade 4. The thickness of the IST was measured by another radiologist with a short-axis view. A generalized estimating equation was used for statistical analysis.

Results

The tendinosis grades were higher in the HC position than in the IR position, with a cumulative odds ratio of 2.087 (0.004, 95% confidence interval [CI]: 1.268-3.433). The tendinosis grades in the HC position (p = 0.370) and IR position (p = 0.146) were not significantly different from those in the N position. The overall difference in IST thickness was significant (p < 0.001), but the visible range (p = 0.530) was not significantly different according to position.

Conclusion

Patient positioning significantly affected the grade of tendinosis and thickness but not the visible range of the IST. The IR position is a feasible position for assessing the IST on US.

Ultrasound imaging of patellar tendon thickness in elite sprint track cyclists and elite soccer players: An intra-rater and inter-rater reliability study

The goal of our study was to investigate the relative and absolute intra-rater and inter-rater reliability of ultrasound assessment of patellar tendon (PT) thickness assessed over four locations, in track cyclists and soccer players. Fifteen male elite track cyclists and 15 male elite soccer players participated. Tendon thickness was measured over 4 locations placed at 5-10-15-20 mm inferior to the apex of the patella by two experienced examiners. Each examiner took two US images for the test measurements with a 10-min rest period. After a 30-min period, the subjects underwent a retest measurements that were also repeated 1-week after. A two-way analysis of variance revealed a significant group x location interaction on PT thickness for Examiner 1 (p = .001, η² = .81) and Examiner 2 (p = 0.001, η² = 0.78). Intra-rater reliability ranged from good to excellent (ICC_2,k ≥ 0.75), whereas inter-rater reliability was good (ICC_2,k ≥ 0.75) in both groups. Ultrasonographic assessment of PT was found to be a reliable method to assess tendon thickness. The middle location of the PT (corresponding to 15 and 20 mm) can be considered the most reliable spot to measure PT thickness. The PT thickness was larger among track cyclists than soccer players, with larger differences over the distal location (15 mm). Ultrasonographic assessment of PT was found to be a reliable method to assess tendon thickness. The middle location of the PT corresponding to 15 mm and 20 mm can be considered the most reliable area to measure PT thickness.

An Isometric and Functionally Based 4-Stage Progressive Loading Program in Achilles Tendinopathy: A 12-Month Pilot Study

Background

Achilles tendinopathy (AT) is a common musculoskeletal disorder, and its management remains challenging. Hypothesis/Purpose. By conducting a pilot study, we aimed to assess the feasibility, safety, and clinical improvement of a new home-based 4-stage rehabilitation program with progressive loading including isometric exercises on a small scale prior to setting up a randomized controlled trial.

Methods

Ten recreational athletes with chronic midportion AT were included. The primary outcome was change in VISA-A score after 1, 2, 3, 6, and 12 months. Secondary outcomes included tenderness on palpation of the tendon and ultrasonographic changes after 6 months.

Results

Average VISA-A improvements of 26.9 points (P=0.004) and 35.4 points (P=0.006) were observed at 6- and 12-month follow-up, respectively. Tenderness on palpation of the tendon (0-10) was reduced from 5.5 to 2.5 (P < 0.001). Color Doppler ultrasound activity (0-4) was reduced by 50%, from an average of grade 2 to grade 1 (P=0.023). The hypoechoic cross-sectional area of the Achilles tendon was reduced from an average of 29.1% to 8.5% (P=0.001). Tendon thickness showed no statistically significant change (P=0.415).

Conclusion

Following the 4-stage rehabilitation program for AT based on isometric training and progressive loading, we observed improvement in both VISA-A score and ultrasonography in a group of athletes who had previously failed to benefit from standard AT rehabilitation. The study was feasible in terms of high adherence to the program and with no observed safety issues. The results of this pilot study support a further assessment of this specific approach for rehabilitation in a future randomized controlled trial.

Validity and reliability of a novel 3D ultrasound approach to assess static lengths and the lengthening behavior of the gastrocnemius medialis muscle and the Achilles tendon in vivo

PURPOSE

Human muscle-tendon units (MTUs) are highly plastic and undergo changes in response to specific diseases and disorders. To investigate the pathological changes and the effects of therapeutic treatments, the use of valid and reliable examination methods is of crucial importance. Therefore, in this study, a simple 3D ultrasound approach was developed and evaluated with regard to: (1) its validity in comparison to magnetic resonance imaging (MRI) for the assessment of the gastrocnemius medialis (GM) MTU, muscle belly, and Achilles tendon lengths; and (2) its reliability for static and dynamic length measurements.

METHODS

Sixteen participants were included in the study. To evaluate the validity and reliability of the novel 3D ultrasound approach, two ultrasound measurement sessions and one MRI assessment were performed. By combining 2D ultrasound and 3D motion capture, the tissue lengths were assessed at a fixed ankle joint position and compared to the MRI measurements using Bland-Altman plots. The intra-rater and inter-rater reliability for the static and dynamic length assessments was determined using the coefficient of variation, standard error of measurement (SEM), minimal detectable change (MDC₉₅), and intraclass correlation coefficient (ICC).

RESULTS

The 3D ultrasound approach slightly underestimated the length when compared with MRI by 0.7%, 1.5%, and 1.1% for the GM muscle belly, Achilles tendon, and MTU, respectively. The approach showed excellent intra-rater as well as inter-rater reliability, with high ICC (≥ 0.94), small SEM (≤ 1.3 mm), and good MDC₉₅ (≤ 3.6 mm) values, with even better reliability found for the static length measurements.

CONCLUSION

The proposed 3D ultrasound approach was found to be valid and reliable for the assessment of the GM MTU, muscle belly, and Achilles tendon lengths, as well as the tissue lengthening behavior, confirming its potential as a useful tool for investigating the effects of training interventions or therapeutic treatments (e.g., surgery or conservative treatments such as stretching and orthotics).

LEVEL OF EVIDENCE

Level II.

Shear wave elastography assessment and comparison study of the Achilles tendons in optimally conditioned asymptomatic young collegiate athletes

OBJECTIVE

To assess the functional parameters of the Achilles tendons among asymptomatic college level athletes using shear wave elastography (SWE) and to describe the relationship to athlete demographics and anthropometric lower extremity measurements.

MATERIAL AND METHODS

Sixty-five athletes were included in this IRB-approved study. SWE measurements were made on two tendon positions (neutral state and active maximum dorsiflexion) with two different probe orientations (longitudinal and transverse). Associations were assessed with BMI, tibial/foot length, type of sports, and resting/maximal dorsiflexion-plantar flexion angles.

RESULTS

Thirty-five (53.8%) males and 30 (46.2%) females with an overall mean age of 20.9 years (± 2.8), mean height of 176 cm (± 0.11), and mean weight of 74.1 kg (± 12) were studied. In the neutral state, the mean wave velocity of 7.5 m sec^-1 and the mean elastic modulus of 176.8 kPa were recorded. In active maximum dorsiflexion, the mean velocity was 8.3 m sec^-1 and mean elastic modulus was 199 kPa. On the transverse view, the mean velocity and elastic measurements were significantly lower (p = 0.0001). No significant differences in SWE parameters were seen between male and female athletes regardless of probe orientation (p < 0.05) with SWE values being higher in the running group vs non-running group (p < 0.05). In neutral state, longitudinal SWE measurements correlated with the tibia-foot length whereas transverse measurements correlated with the tendon diameter and ankle resting angle (ARA) (p < 0.005).

CONCLUSION

SWE can distinguish functional differences in Achilles tendon stiffness between athletes engaged in running-intensive sports compared with other athletes.

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

Ultrasound can be used to assess injury and structural changes to the soft-tissue structure of the foot. It may be useful to assess the feet of people with diabetes who are at increased risk of plantar soft-tissue pathological changes. The aim of this study was to determine if ultrasound measurements of plantar soft-tissue thickness and assessments of tissue acoustic characteristics are reliable in people with and without diabetes mellitus. A repeated measures design was used to determine intra-observer reliability for ultrasound measurements of plantar skin and fat pad thickness and intra- and inter-observer reliability of plantar skin and fat pad tissue characterisation assessments made at foot sites which are at risk of tissue injury in people with diabetes. Thickness measurements and tissue characterisation assessments were obtained at the heel and forefoot in both the unloaded and compressed states and included discrete layers of the plantar tissues: skin, microchamber, horizontal fibrous band, macrochamber and total soft-tissue depth. At each site, relative intra-observer reliability was achieved for the measurement of at least one plantar tissue layer. The total soft-tissue thickness measured in the unloaded state (ICC 0.925-0.976) demonstrated intra-observer reliability and is the most sensitive for detecting small change on repeated measures. Intra-observer agreement was demonstrated for tissue characteristic assessments of the skin at the heel (k = 0.70), fat pad at the lateral sesamoid region (k = 0.70) and both skin and fat pad at the second (k = 0.80, k = 0.70 respectively) and third metatarsal heads (k = 0.90, k = 0.79 respectively). However, acceptable inter-observer agreement was not demonstrated for any tissue characteristic assessment, therefore the use of multiple observers should be avoided when making these assessments.

A Narrative Review of the Classification and Use of Diagnostic Ultrasound for Conditions of the Achilles Tendon

Enthesitis is a cardinal feature of spondyloarthropathies. The Achilles insertion on the calcaneus is a commonly evaluated enthesis located at the hindfoot, generally resulting in hindfoot pain and possible tendon enlargement. For decades, diagnosis of enthesitis was based upon patient history of hindfoot or posterior ankle pain and clinical examination revealing tenderness and/or enlargement at the site of the tendon insertion. However, not all hindfoot or posterior ankle symptoms are related to enthesitis. Advanced imaging, including magnetic resonance imaging (MRI) and ultrasound (US), has allowed for more precise evaluation of hindfoot and posterior ankle conditions. Use of US in diagnosis has helped confirm some of these cases but also identified other conditions that may have otherwise been misclassified without use of advanced imaging diagnostics. Conditions that may result in hindfoot and posterior ankle symptoms related to the Achilles tendon include enthesitis (which can include retrocalcaneal bursitis and insertional tendonopathy), midportion tendonopathy, paratenonopathy, superficial calcaneal bursitis, calcaneal ossification (Haglund deformity), and calcific tendonopathy. With regard to classification of these conditions, much of the existing literature uses confusing nomenclature to describe conditions in this region of the body. Some terminology may imply inflammation when in fact there may be none. A more uniform approach to classifying these conditions based off anatomic location, symptoms, clinical findings, and histopathology is needed. There has been much debate regarding appropriate use of tendonitis when there is no true inflammation, calling instead for use of the terms tendinosis or tendonopathy. To date, there has not been clear examination of a similar overuse of the term enthesitis in conditions where there is no underlying inflammation, thus raising the need for more comprehensive taxonomy.

Intra- and inter-rater reproducibility of ultrasound imaging of patellar and quadriceps tendons in critically ill patients

Since the outset of body image reconstruction for diagnosis purposes, ultrasound has been used to investigate structural changes located in tendons. Ultrasound has clinical applications in the intensive care unit, but its utility for tendon imaging remains unknown. Thus, we aimed to determine intra- and inter-rater reproducibility of measures obtained by images generated through morphological tendon sonographic analysis recorded from critically ill patients. We designed a cross-sectional study to assess thickness, cross-sectional area, and echogenicity of patellar and quadriceps tendons in a convenience sample formed with 20 critically ill patients. Two independent raters (experienced and novice) recorded repeated measures, checking for agreement (Kappa statistics) and reliability (Intraclass coefficient Correlation-ICC and Bland-Altman). The quality of images acquired by the two independent raters substantially agreed (k = 0.571–1.000), regardless of the region on the patellar tendon or the studied tendon (patellar or quadriceps). Regardless of how much experience the rater had, their repeated records (intra-rater reliability) always demonstrated almost complete correlation, ICC ranging from 0.89 to 0.98 for both tendons in all outcomes. At the same way, the statistically significant inter-rater ICC ranging from 0.87 to 0.97. Both repeated measures by the raters (intra-rater) and the repeated single and double measures between the raters (inter-rater) presented a minimum measurement error constituting a predominant pattern of random variability. We conclude that ultrasound imaging acquisition performed by independent raters for tendon thickness, CSA, and echogenicity monitoring of critically ill patients are acceptable and are not influenced by rater experience.

Ultrasonographic assessment of patellar tendon thickness at 16 clinically relevant measurement sites - A study of intra- and interrater reliability

OBJECTIVES

To determine intra- and interrater reliability of ultrasonographic imaging (USI) measurements of patellar tendon (PT) thickness using 16 measurement sites covering the entire tendon.

DESIGN

Reliability study.

SETTING

Physiotherapy outpatient clinic.

PARTICIPANTS

Twenty healthy and physically active volunteers (9 women). Mean age: 24 years (SD ± 2.73). Mean body mass: 75.8 kg (SD ± 11.8).

MAIN OUTCOME MEASURES

Intraclass correlation coefficient (ICC) and 95% limits of agreement (LOA) in cm and in percentage relative to the mean PT thickness.

RESULTS

Intrarater reliability ranged from 0.59 to 0.87 and 0.59 to 0.93 for examiners I and II, respectively. Interrater reliability ranged from 0.37 to 0.89. Measurement precision for examiner I ranged from 0.05 to 0.09 cm (17.5%-26.7%) while ranging from 0.04 to 0.13 cm (13.3%-38.7%) for examiner II. Interrater measurement precision ranged from 0.07 to 0.15 cm (19.1%-42.5%).

CONCLUSION

In an attempt to replicate daily clinical USI practice, this was the first study extensively assessing reliability throughout the full range of the patellar tendon - revealing a considerable variation in intra- and interrater reliability as well as measurement precision throughout the 16 individual PT sites. In a clinical context, the low interrater reliability and precision found at the proximal tendon insertion site may have implications for USI of the symptomatic PT, as this is the site mainly associated with underlying pathologic changes. Further reliability studies are needed to clarify the region-specific reliability of the full length PT.

Comparison of the sonographic features of the Achilles Tendon complex in patients with and without achilles tendinopathy: A case-control study

AIM

The aim of the present study was to evaluate and quantify with ultrasound imaging (USI) the Achilles tendon thickness, cross-sectional area (CSA), Kager's fat pad length and gastrocnemius-soleus pennation angle (PA) between chronic mid-portion Achilles tendinopathy (AT) and healthy subjects.

METHODS

A total sample of 143 individuals (age: 41.3 ± 12.0 y; height: 1.74 ± 0.0 m; weight: 75.0 ± 11.4 kg; body mass index, BMI: 24.4 ± 2.6 kg/m²) was recruited and divided in two groups: chronic mid-portion AT group (n = 71) and a healthy group (n = 72).

RESULTS

The thickness and CSA at 4 cm and 6 cm from the calcaneus was increased showing statistically significant differences (P < .01) in favor the tendinopathy group. For the gastrocnemius-soleus PA and Kager's fat pad length, significant differences (P < .01) were observed for a decrease in favor of the tendinopathy group.

CONCLUSIONS

This study reported an increase of Achilles tendon thickness and CSA at 4 cm and 6 cm from the calcaneus as well as a decrease in gastrocnemius-soleus PA and Kager's fat pad length in patients with chronic mid-portion AT.

Are Ultrasound Measurements of Achilles Tendon Size Reliable? A Systematic Review of Rater Reliability

Ultrasound measurements of Achilles tendon size are used to assess the tendon's response to exercise, aging, rehabilitation, tendon loading and healing. It is important to understand and minimise the measurement error that occurs with these measurements. This review identified and synthesised studies reporting on intra- and inter-rater reliability of ultrasound measurements of Achilles tendon size. Analysis of 21 studies revealed that good to excellent intra- and inter-rater reliability can be achieved for ultrasound measurements of Achilles tendon size. Reliability can be optimised by using one experienced operator, standardising transducer pressure and orientation and averaging two or three measurements. There was a high risk of methodological bias across the included studies. Reporting of reliability studies needs to be improved by the use of existing reporting guidelines and expansion of these guidelines to include important elements of ultrasound imaging.

Ultrasonographic evaluation of the ankle after unilateral traumatic lower limb amputations

BACKGROUND

Unilateral lower limb amputation can alter the tissue morphology leading to increase future risk of degenerative secondary disorders.

METHODS

Thirty-four consecutive male patients with unilateral lower limb amputations of different levels and 34 well matched male controls were included. To explore whether the ankles of traumatic lower limb amputees were undergoing morphological changes, three different tissue types i.e. talar cartilage, plantar fascia and Achilles tendon thicknesses in the intact limb of the lower limb amputee and healthy controls were measured by using ultrasound.

RESULTS

Plantar fascia was found to be thicker (p=0.013) and talar cartilage was thinner (p<0.001) on the intact sides of the patients than those of the controls. Achilles tendon thickness was found to be similar. In patients group, plantar fascia thickness was positively correlated with age (r=0.601, p<0.001), BMI (r=0.454, p=0.007) and durations of amputation (r=0.443, p=0.009) and prosthetic use (r=0.429, p=0.011). Achilles tendon thickness was positively correlated with durations of amputation (r=0.338, p=0.05) and prosthetic use (r=0.468, p=0.005). In controls group, talar cartilage thickness was negatively correlated with age (r=-0.640, p<0.001) and BMI (r=-0.401, p=0.019).

CONCLUSIONS

The talar cartilage seemed to be thinner and the plantar fascia to be thicker on the intact sides of the unilateral limb amputees.

The Achilles Tendon in Healthy Subjects: An Anthropometric and Ultrasound Mapping Study

Ultrasonography is an inexpensive, fast, and reliable imaging technique widely used to assess the Achilles tendon. Although significant data exists regarding pathologic tendon changes, ultrasound data from healthy individuals are more limited. We aimed to better characterize ultrasound Achilles tendon measurements in healthy individuals and identify important correlating factors. The information collected included patient demographics, body habitus, activity level, foot dominance, and resting ankle angle. Ultrasound analysis was performed bilaterally on the Achilles tendons of 50 subjects using a high-frequency transducer to measure tendon width, thickness, cross-sectional area, and length. Males had a significantly larger mean tendon length, width, thickness, and cross-sectional area. No statistically significant difference was found in any tendon dimension between the white and black participants. Similarly, no difference was found in any tendon parameter when comparing right versus left leg dominance. Healthy subjects had a mean ankle resting angle of 45.1° ± 24° with no statistically significant difference between right and left ankles. Considering all individuals, each tendon parameter (tendon length, width, thickness, and cross-sectional area) correlated positively with subject height, weight, tibia length, and foot size. Only the Achilles cross-sectional area correlated significantly with the activity level. The resting angle of the ankle correlated positively with both tendon length and thickness. In conclusion, we found significant variations in Achilles tendon anatomy in the healthy adult population. We have thoroughly characterized significant correlations between healthy tendon dimensions and various body habitus, activity levels, and ankle parameters. Greater knowledge of the normal Achilles tendon anatomy and characterization of its variations in the healthy population will potentially allow for better pathologic diagnosis and surgical repair.

Muscle-tendon-related abnormalities detected by ultrasonography are common in symptomatic hip dysplasia

INTRODUCTION

Hip dysplasia is characterized by reduced acetabular coverage of the femoral head leading to an increased mechanical load on the hip joint and the acting hip muscles. Potentially, the muscles and tendons functioning close to the hip joint may present with overuse-related ultrasonography findings. The primary aim was to report the prevalence of muscle-tendon-related abnormalities detected by ultrasonography in 100 patients with symptomatic hip dysplasia. The secondary aim was to investigate correlations between muscle-tendon-related abnormalities detected by ultrasonography and clinically identified pain related to muscles and tendons.

MATERIALS AND METHODS

One hundred patients (17 men) with a mean age of 29 ± 9 years were included. Muscle-tendon-related abnormalities were detected with a standardized ultrasound examination. Correlations between muscle-tendon-related abnormalities detected by ultrasonography and clinically identified pain related to muscles and tendons were tested with Spearman's rank correlation coefficient.

RESULTS

The most prevalent ultrasonography findings were identified in the iliopsoas tendon [50% (95% CI 40; 60)], the adductor longus tendon [31% (95% 22; 40)] and the gluteus medius/minimus tendons [27% (18; 36)]. Significant correlations between ultrasonography findings and pain related to muscles and tendons were only found for the iliopsoas tendon (ρ = 0.24 and p = 0.02) and the gluteus medius/minimus tendons (ρ = 0.35 and p < 0.001).

CONCLUSIONS

Muscle-tendon-related abnormalities detected by ultrasonography in the hip and groin region are common in patients with symptomatic hip dysplasia, and the ultrasonography findings of the iliopsoas and gluteus medius/minimus tendons are weakly to moderately correlated to pain related to muscles and tendons in these structures. Both the iliopsoas and the gluteus medius/minimus have a pronounced stabilizing role in the dysplastic hip joint, and the common muscle-tendon-related abnormalities in these patients may be caused by injuries related to excessive use or degenerative changes in the muscle-tendon tissue.

Ultrasound measures of tendon thickness: Intra-rater, Inter-rater and Inter-machine reliability

BACKGROUND

Ultrasound imaging is often used by physiotherapists and other healthcare professionals but the reliability of image acquisition with different ultrasound machines is unknown. The objective was to compare the intra-rater, inter-rater and intermachine reliability of thickness measurements of the plantar fascia (PF), Achilles tendon (AT), patellar tendon (PT) and elbow common extensor tendon (ECET) with musculoskeletal ultrasound imaging (MSUS).

METHODS

Tendon thickness was measured in four anatomical structures (14 participants, 28 images per tendon) by two sonographers and with two different ultrasound machines. Intraclass Correlation Coefficients (ICCs) and Bland-Altman plots were calculated. The standard error of measurement (SEM) and minimum detectable difference (MDD) were calculated.

RESULTS

Inter-rater reliability was excellent for AT (ICC=0.98; 95% CI= 0.96-0.99) and very good for PT (ICC=0.85; 95% CI = 0.67-0.93) and ECET (ICC=0.81; 95% CI= 0.72-0.94). Reliability for PF was moderate, with an ICC of 0.63 (CI 95%= 0.20-0.83). Bland-Altman plot for inter-machine reliability showed a mean difference of 1 m for PF measurements and a mean difference of 4 m and 20 m for AT and PT. The relative SEMs were below 7% and the MDCs were below 0.7 mm.

CONCLUSION

The MSUS reliability in measuring thickness of the four tendons is confirmed by the homogeneous readings intra sonographers, between operators and between different machines. Level of evidence: Tendon thickness can be measured reliably on different ultrasound devices, which is an important step forward in the use of this technique in daily clinical practice and research.

LEVEL OF EVIDENCE

III.

A systematic review of the reliability of diagnostic ultrasound imaging in measuring tendon size: Is the error clinically acceptable?

BACKGROUND

Diagnostic ultrasound (US) is a commonly used imaging modality for visualising tendon pathology and morphology. In comparison to magnetic resonance imaging (MRI), diagnostic US is perceived to have a higher risk of error when evaluating tendon size.

AIM

To systematically assess the evidence regarding the Intra rater and Inter rater reliability of diagnostic US measurements of tendon size.

DATA SOURCES

Eight electronic databases were searched using an agreed set of keywords. Studies which investigated the reliability of tendon size (thickness or cross sectional area) using diagnostic US were eligible.

RESULTS

Combined Inter rater and Intra rater ICC values for tendon thickness ranged from 0.45 to 0.99. Combined Inter rater and Intra rater ICC values for tendon cross-sectional area (CSA) ranged from 0.58 to 0.92. Overall, Intra rater ICC values (0.59-0.99) were marginally higher than Inter rater values (0.45-0.99) across all tendon sites. Percentage co-efficient of variation (CV%) for tendon thickness and CSA ranged from 0 to 35% across all tendons. Percentage standard error of the mean SEM% values for tendon thickness ranged from 3.33% to 7.39%.

CONCLUSIONS

The findings of this review suggest diagnostic US measures of tendon size are reliable, both in terms of relative and absolute reliability. However, the findings must be considered in light of the presence of tendon abnormalities in a large percentage of asymptomatic populations.

Ultrasound and magnetic resonance imaging are not interchangeable to assess the Achilles tendon cross-sectional-area

Purpose

The major aim of this study was to compare ultrasound (US) and magnetic resonance imaging (MRI) measurements of the Achilles tendon cross-sectional area (CSA). Further aims were to conduct reliability analyses and to assess the influence of transducer pressure on the tendon properties in US measurements.

Methods

The Achilles tendon CSA of 15 participants was assessed at two positions with US and MRI by use of a standardized protocol. Method comparison was performed by two-way analysis of variance (ANOVA) and paired t test. Reliability was assessed by coefficients of variation (CV), intraclass correlation (ICC_2,2), standard error of measurement (SEM), and minimal detectable change (MDC₉₅). A paired t test was performed to investigate the effect of probe pressure on tendon CSA and thickness.

Results

Mean US measurements provided a ~5.5% smaller CSA compared to MRI measurements. Intra-rater reliability analyses of US demonstrated CV values of 1.5–4.9%, ICC of 0.89–0.97, SEM and MDC₉₅ values of 0.22–0.77 mm² and 0.61–2.16 mm² for both raters, whereby CV values for intra-rater reliability of MRI ranged from 1.0 to 3.7%. Inter-rater reliability was lower for both modalities. Pressure applied on the transducer altered Achilles tendon CSA and thickness significantly (p < 0.05).

Conclusions

Our findings show that US and MRI cannot be used interchangeably for Achilles tendon CSA assessments, however, each imaging modality separately is reliable to assess this property. Pressure applied on the transducer during US measurements causes alterations of the tendon’s morphology and should be avoided.

Sonographic measurements of the achilles tendon, plantar fascia, and heel fat pad are reliable: A test-retest intra- and intertester study

PURPOSE

To determine intra- and interobserver reliability and precision of sonographic (US) scanning in measuring thickness of the Achilles tendon, plantar fascia, and heel fat pad in patients with heel pain.

METHODS

Seventeen consecutive patients referred with heel pain were included. Two evaluators blinded to the diagnosis performed independently US scanning of both feet without any dialogue with the patient. The examiner left the room, and the next examiner entered. All patients had two US scans performed by each examiner. Two months later, the US images were randomly presented to the evaluators for measurements. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC), 95% limits of agreement (LOA), and typical error (TE). LOA was calculated as a percentage of the mean thickness of each structure to obtain a unitless parameter.

RESULTS

We found excellent intratester reliability (ICC 0.78-0.98) and good intertester reliability using one measurement (ICC 0.72-0.91) and excellent (ICC 0.85-0.95) when using average of two measurements. The intratester agreements were good with LOA: 9.5-23.4% and TE: 3.4-8.4%. The intertester agreements were acceptable using one measurement with LOA: 16.1-36.4%, and better using two measurements with LOA: 14.4-33.2%.

CONCLUSIONS

US is a reliable technique of measurement in the daily clinic, and one single measurement is sufficient. In research, we recommend that the same observer performs the US measurements, if one single scanning is preferred; if more researchers are involved, the average measurement of two US scans is recommended. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:480-486, 2016.

Quantitative ultrasound imaging of Achilles tendon integrity in symptomatic and asymptomatic individuals: reliability and minimal detectable change

Background

Quantifying the integrity of the Achilles tendon (AT) is a rehabilitation challenge. Adopting quantitative ultrasound measurements (QUS measurements) of the AT could fill this gap by 1) evaluating the test-retest reliability and accuracy of QUS measurements of the AT; 2) determining the best protocol for collecting QUS measurements in clinical practice.

Methods

A total of 23 ATs with symptoms of Achilles tendinopathy and 63 asymptomatic ATs were evaluated. Eight images were recorded for each AT (2 visits × 2 evaluators × 2 images). Multiple sets of QUS measurements were taken: geometric (thickness, width, area), first-order statistics (computed from a grayscale histogram distribution: echogenicity, variance, skewness, kurtosis, entropy) and texture features (computed from co-occurrence matrices: contrast, energy, homogeneity). A generalizability study quantified the reliability and standard error of measurement (accuracy) of each QUS measurement, and a decision study identified the best measurement taking protocols.

Results

Geometric QUS measurements demonstrated excellent accuracy and reliability. QUS measurements computed from the grayscale histogram distribution revealed poor accuracy and reliability. QUS measurements derived from co-occurrence matrices showed variable accuracy and moderate to excellent reliability. In clinical practice, using an average of the results of three images collected by a single evaluator during a single visit is recommended.

Conclusions

The use of geometric QUS measurements enables quantification of AT integrity in clinical practice and research settings. More studies on QUS measurements derived from co-occurrence matrices are warranted.

Ultrasound-guided dry needling with percutaneous paratenon decompression for chronic Achilles tendinopathy

PURPOSE

Chronic Achilles tendinopathy is a common overuse injury. There are several modalities of treatment, reflecting difficulties in management. In particular, due to the well-recognised surgical morbidity, treatment has steered towards less invasive routes. Previous studies have targeted pathology either inside or outside the tendon in isolation with varying results. This study aimed to target both pathological sites by combining dry needling with percutaneous hydrostatic decompression as a novel treatment.

METHODS

Twenty-one patients with 26 chronic, non-insertional Achilles tendinopathy were prospectively enrolled. Ultrasound-guided dry needling of neovascular areas and small-volume hydrostatic paratenon decompression was performed 6-weekly. Sonographic assessment of tendon thickness and neovascularity was undertaken. Following treatment, a standardised physiotherapy regime was adopted. Visual analogue scores (VAS) were used as the primary outcome measure. Telephonic interviews were carried out 12 and 24 months post-treatment.

RESULTS

Twenty-four tendons (in 19 patients) were successfully treated. The mean treatment session was 2. There was no significant change in neovascularity or tendon thickness. Therapeutic intervention led to a significant improvement in VAS at rest (42.4 ± 24.4 vs. 18.4 ± 26.0, p = 0.0005) and during activity (72.8 ± 16.0 vs. 33.7 ± 23.2, p < 0.0001). At 12 and 24 months, >75 % of patients were highly satisfied with their outcome with nearly half reporting complete resolution of their symptoms. >85 % were also able to return to their sporting interests.

CONCLUSION

Combined therapy of dry needling with percutaneous hydrostatic paratenon decompression under ultrasound guidance is a well-tolerated procedure with good short- and long-term pain and functional outcomes.

LEVEL OF EVIDENCE

Prospective case series, Level IV.

Ultrasound assessment for grading structural tendon changes in supraspinatus tendinopathy: an inter-rater reliability study

AIM

To evaluate the inter-rater reliability of measuring structural changes in the tendon of patients, clinically diagnosed with supraspinatus tendinopathy (cases) and healthy participants (controls), on ultrasound (US) images captured by standardised procedures.

METHODS

A total of 40 participants (24 patients) were included for assessing inter-rater reliability of measurements of fibrillar disruption, neovascularity, as well as the number and total length of calcifications and tendon thickness. Linear weighted κ, intraclass correlation (ICC), SEM, limits of agreement (LOA) and minimal detectable change (MDC) were used to evaluate reliability.

RESULTS

'Moderate-almost perfect' κ was found for grading fibrillar disruption, neovascularity and number of calcifications (k 0.60-0.96). For total length of calcifications and tendon thickness, ICC was 'excellent' (0.85-0.90), with SEM(Agreement) ranging from 0.63 to 2.94 mm and MDC(group) ranging from 0.28 to 1.29 mm. In general, SEM, LOA and MDC showed larger variation for calcifications than for tendon thickness.

CONCLUSIONS

Inter-rater reliability was moderate to almost perfect when a standardised procedure was applied for measuring structural changes on captured US images and movie sequences of relevance for patients with supraspinatus tendinopathy. Future studies should test intra-rater and inter-rater reliability of the method in vivo for use in clinical practice, in addition to validation against a gold standard, such as MRI.

TRIAL REGISTRATION NUMBER

NCT01984203; Pre-results.

Ultrasound measures of supraspinatus tendon thickness and acromiohumeral distance in rotator cuff tendinopathy are reliable

PURPOSE

Rotator cuff (RC) tendinopathy has been widely ascribed to impingement of the supraspinatus tendon (SsT) in the subacromial space, measured as the acromiohumeral distance (AHD). Ultrasound (US) is suitable for measuring AHD and SsT thickness, but few reliability studies have been carried out in symptomatic populations, and interrater reliability is unconfirmed. This study aimed to examine the intrarater and interrater reliability of US measurements of AHD and SsT thickness in asymptomatic control subjects and patients with RC tendinopathy.

METHODS

Seventy participants were recruited and grouped as healthy controls (n = 25) and RC tendinopathy (n = 45). Repeated US measurements of AHD and SsT thickness were obtained by one rater in both groups and by two raters in the RC tendinopathy group.

RESULTS

Intrarater and interrater reliability coefficients were excellent for both measurements (intraclass correlation > 0.92), but the intrarater reliability was superior. The minimal detectable change values in the symptomatic group were 0.7 mm for AHD and 0.6 mm for SsT thickness for a single experienced examiner; the values rose to 1.2 mm and 1.3 mm, respectively, for the pair of examiners.

CONCLUSIONS

The results support the reliability of US for the measurement of AHD and SsT thickness in patients with symptomatic RC tendinopathy and provide minimal detectable change values for use in future research studies.

Longitudinal In Vivo Ultrasound Observations of the Surgically Repaired Zone II Flexor Digitorum Profundus Tendon

The link between the healing process and functional outcomes in the surgically repaired digital flexor tendon is poorly understood. This clinical note describes those gray-scale and power Doppler (PD) ultrasound parameters that can be used to document longitudinal change in the morphologic and dynamic properties of the surgically repaired zone II flexor digitorum profundus (FDP) tendon. The method is supported by ultrasound data obtained from three participants at five points in time post-surgically (two, four, six, 12 and 18 weeks). Longitudinal documentation of the ultrasound properties of echogenicity, defect size, tendon excursion and power Doppler signal is feasible and has the potential to explore the possible link between changes in the structural status of surgically repaired flexor tendons and associated clinical outcomes.

Tendinopathy of the achilles tendon: volume assessed by automated contour detection in submillimeter isotropic 3-dimensional magnetic resonance imaging data sets recorded at a field strength of 3 T

OBJECTIVE

This prospective study assesses volume changes of the Achilles tendon in case of chronic tendinopathy (TEN), using an automated contour detection algorithm in submillimeter isotropic 3-dimensional magnetic resonance imaging data sets, recorded at 3 T.

METHODS

Forty-one subjects (median age, 40 years; range, 19-68 years) were included in this prospective study and underwent nonenhanced magnetic resonance imaging of both Achilles tendons at 3 T, deploying a T2-weighted 3-dimensional Fast-Spin-Echo sequence with submillimeter resolution of 0.8 mm. Of the 41 subjects, 13 were classified as patients with TEN and 28 were healthy volunteers and served as control group. Of the 13 patients, 10 had unilateral TEN and 3 had bilateral TEN. Achilles tendons were automatically segmented in the T2-weighted magnetic resonance data sets for the evaluation of the tendon volume (0-3 cm proximal to the cranial border of the calcaneal bone). The total volume (length, 3 cm) was divided in 3 subvolumes of 1 cm length, named volume (0-1 cm), volume (1-2 cm), and volume (2-3 cm). Minimum and maximum tendon cross-sectional area within the total volume was processed. A standardized pain questionnaire was obtained from all patients.

RESULTS

The automated contour detection algorithm worked reliably in all cases. The TEN group showed a significantly increased tendon volume compared to the control group (mean volume, 2.94 vs 2.43 mm; P < 0.05). The difference was most obvious concerning volume (2-3 cm) (P < 0.0001). Evaluation of clinical severity revealed a moderate correlation between VISA-score and tendon volume (2-3 cm) as well as the maximum/minimum tendon area (ρ = -0.44, ρ = -0.48, and ρ = -0.41). In case of unilateral TEN, the symptomatic side showed an increased tendon volume (2-3 cm) and increased minimum area (P < 0.05).

CONCLUSIONS

Tendon volume and size are adequate surrogate parameters to differentiate patients with chronic TEN from healthy subjects, and may discriminate symptomatic TEN from asymptomatic "silent" TEN in patients with unilateral symptoms.

Ultrasound vs. MRI in the assessment of rotator cuff structure prior to shoulder arthroplasty

BACKGROUND/AIMS

We compared the accuracy of US to 3 T Tesla MRI for the detection of rotator cuff and long biceps tendon pathologies before joint replacement.

METHODS

45 patients were prospectively included.

RESULTS

For the supraspinatus tendon, the accuracy of US when using MRI as reference was 91.1%. For the infraspinatus tendon, the accuracy with MRI as reference was 84.4%. The subscapularis tendon was consistently assessed by US and MRI in 35/45 patients (accuracy 77.8%). For the long biceps tendon the accuracy was 86.7%.

CONCLUSION

US detection of rotator cuff and biceps tendon integrity is comparable to MRI and should be preferred in revision cases.

Ultrasound dimensions of the rotator cuff in young healthy adults

BACKGROUND

No studies have looked at the rotator cuff dimensions in the young healthy population using ultrasonography. Our aim is to define the ultrasound dimensions of the rotator cuff in the healthy young adult population and explore correlations with other patient characteristics.

METHODS

Thirty male and 30 female healthy volunteers (aged 18-40 years), with no shoulder problems, underwent ultrasound assessment of both shoulders by a musculoskeletal radiologist. The dimensions of the rotator cuff, deltoid, and biceps were measured in a standardized manner.

RESULTS

A total of 120 shoulders were scanned. The mean maximum width of the supraspinatus footprint was 14.9 mm in men and 13.5 mm in women (P < .001). The mean thickness of the supraspinatus tendon was 4.9 mm in women and 5.6 mm in men. The mean thickness of the subscapularis was 4.4 in men and 3.8 mm in women and for the infraspinatus was 4.9 mm in men and 4.4 mm in women. There was no correlation between height, weight, biceps, or deltoid thickness with any tendon measurements. Apart from supraspinatus tendon thickness, the difference between dominant and nondominant shoulders in the same sex was not significant for any other tendon dimensions.

CONCLUSION

This study has defined the dimensions of the rotator cuff in the young healthy adult, which has not been previously published. This is important for the documentation of normal ultrasound anatomy of the rotator cuff and also demonstrates that the asymptomatic contralateral shoulder can and should be used to estimate the expected dimensions.

Patellar tendinopathy: preliminary surgical results

Background:

Calcific deposits (CaDs) may be related to chronic postoperative pain and may affect function after patellar tendon surgery.

Study Design:

Cross-sectional.

Hypothesis:

We hypothesized that patients with CaDs (+CaDs) would rate lower than those without (−CaDs) on measures of knee function and quality of life.

Methods:

Patients completed the Tegner Lysholm Knee Scoring Scale (Lysholm), Knee Injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee Subjective Knee Form (IKDC), and the Tegner Activity Level Scale. Sixteen postsurgical and 16 age-matched controls were tested. Patients +CaDs were 5.6 years older than those patients −CaDs and had 4.2 years of longer elapse since surgery. Bilateral patellar tendons were examined for CaDs with musculoskeletal ultrasound imaging. One-way analysis of variance was used to determine if differences existed among patients +CaDs and −CaDs and healthy controls. Hierarchical logistic regressions were used to determine which variables best predicted the presence of CaDs.

Results:

CaDs were found in 44% (7 of 16) of postsurgical patients, who scored lower than controls on all dimensions of the Lysholm, KOOS, and IKDC. Patients +CaD had lower KOOS scores than controls (symptoms, activities of daily living, and quality of life). Age and time since surgery were both moderately related to the presence of CaDs, and both correctly predicted 71% of patients +CaDs.

Conclusion:

Calcific deposits were found in the patellar tendon of 44% of postsurgical patients, who rated themselves lower on all subjective measures of knee function and quality of life following surgery. Age is an important factor for developing CaDs postsurgery.

Clinical Relevance:

Calcific deposits may be present in patellar tendons following surgery, but their direct role in functional or clinical limitations remains unknown.

Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis

Background

Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement.

Methods

20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12- week exercise programme of eccentric calf-muscle training. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire.

Results

In the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment.

Conclusion

In Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.

The opinion and experiences of Dutch orthopedic surgeons and radiologists about diagnostic musculoskeletal ultrasound imaging in primary care: a survey

INTRODUCTION AND AIM

The use of diagnostic musculoskeletal ultrasound (DMUS) in primary health care has increased in the recent years. Nevertheless, there are hardly any data concerning the reliability, accuracy and treatment consequences of DMUS used by physical therapists or general practitioners. Moreover, there are no papers published about how orthopedic surgeons or radiologists deal with the results of DMUS performed in primary care. Therefore, our aim is to evaluate the opinion, possible advantages or disadvantages and experiences of Dutch orthopedic surgeons and radiologists about DMUS in primary care.

METHODS

A cross-sectional survey in which respondents completed a self-developed questionnaire to determine their opinion, experiences, advantages, disadvantages of performing DMUS in primary care.

RESULTS

Questionnaires were sent to 838 Dutch orthopedic surgeons and radiologists of which 213 were returned (response rate 25.4%). Our respondents saw no additional value for health care for diagnostic DMUS in primary care. DMUSs were generally repeated in secondary care. They perceived more disadvantages than advantages of performing DMUS in primary care. Mentioned disadvantages were: 'false positive results' (71.4%), 'lack of experience' (70%), 'insufficient education' (69.5%), not able to relate the outcomes of DMUS with other forms of diagnostic imaging' (65.7%), and 'false negative results' (65.3%).

CONCLUSION

Radiologists and orthopedic surgeons sampled in the Netherlands show low trust in DMUS knowledge of physical therapists and general practitioners. The results should be interpreted with caution because of the small response rate and the lack of representativeness to other countries.

Inter-rater, intra-rater, and inter-machine reliability of quantitative ultrasound measurements of the patellar tendon

The use of ultrasound (US) to perform quantitative measurements of musculoskeletal tissues requires accurate and reliable measurements between investigators and ultrasound machines. The objective of this study was to evaluate inter-rater and intra-rater reliability of patellar tendon measurements between providers with different levels of US experience and inter-machine reliability of US machines. Sixteen subjects without a history of knee pain were evaluated with US examinations of the patellar tendon. Each tendon was scanned independently by two investigators using two different ultrasound machines. Tendon length and cross-sectional area (CSA) were obtained, and examiners were blinded to each other's results. Tendon length was measured using a validated system involving surface markers and calipers, and CSA was measured using each machine's measuring software. Intra-class correlation coefficients (ICCs) were used to determine reliability of measurements between observers, where ICC > 0.75 was considered good and ICC > 0.9 was considered excellent. Inter-rater reliability between sonographers was excellent and revealed an ICC of 0.90 to 0.92 for patellar tendon CSA and an ICC of 0.96 for tendon length. ICC for intra-rater reliability of tendon CSA was also generally excellent, with ICC between 0.87 and 0.96. Inter-machine reliability was excellent, with ICC of 0.91-0.98 for tendon CSA and 0.96-0.98 for tendon length. Bland-Altman plots were constructed to measure validity and demonstrated a mean difference between sonographers of 0.03 mm(2) for CSA measurements and 0.2 mm for tendon length. Using well-defined scanning protocols, a novice and an experienced musculoskeletal sonographer attained high levels of inter-rater agreement, with similarly excellent results for intra-rater and inter-machine reliability. To our knowledge, this study is the first to report inter-machine reliability in the setting of quantitative musculoskeletal ultrasound.

[Is routine implant removal after trauma surgery sensible?]

We present a literature review about implant removal after operative extremity and spine fracture treatment. The indication for implant removal procedures has become less frequent in recent years, but is still more common in Europe than for example in North America. The time required to perform a implant removal can easily exceed the planned amount. Implant removal can result in significant complications like soft tissue damage, fractures, infections, and other problems. Not only because of these problems, the decision on whether or not to remove the implant should be made with great care. Therefore good communication with the patient and thorough information about risks and benefits are essential.

Ultrasound assessment of transverse carpal ligament thickness: a validity and reliability study

The transverse carpal ligament (TCL) forms the palmar boundary of the carpal tunnel and plays an important role in carpal tunnel mechanics. TCL hypertrophy has been observed for individuals with carpal tunnel syndrome (CTS) and postulated as a potential etiologic factor. Ultrasound is particularly advantageous for TCL imaging because of its capability of detecting the interfaces between the TCL and other tissues. The purposes of this study were to develop an ultrasound based method to measure the TCL thickness and to test the validity and reliability of this method. Three operators conducted two sessions of ultrasound examination on eight cadaveric specimens and eight healthy volunteers. A custom script was used to calculate TCL thickness along the TCL length from the ultrasound images. The ultrasound based TCL thickness of the cadaveric specimens was compared with the dissection based TCL thickness for validation. The results showed Pearson's correlation coefficients of 0.867-0.928, intraclass correlation coefficient (ICC) values of 0.726-0.865, a standard error of measurement of 0.02-0.07 mm and a minimal detectable difference of 0.05-0.15 mm. The high correlation coefficients and small errors indicate that the ultrasound based method is valid for measuring TCL thickness. Furthermore, ultrasound measurements showed excellent intraoperator and interoperator reliability with ICC values as 0.826-0.933 and 0.840-0.882, respectively. The ultrasound based TCL thickness was in the range of 0.93-2.34 (1.54 ± 0.33) mm and agreed well with previous studies. The ultrasound method developed in this study is a valuable tool to examine morphologic properties of healthy and pathologic TCLs.

A novel sonographic method of measuring patellar tendon length

Obtaining accurate and readily repeatable measurements is a prerequisite for using measures of soft tissue structures both clinically and in the research setting. Few studies have evaluated the interrater reliability of ultrasound measurements of tendons. The objective of this study was to determine the accuracy and reliability of a new method of sonographic measurement of patellar tendon length using direct dissection as the gold standard. Four cadaveric knees were sonographically evaluated by two independent investigators. Two custom designed straps with nylon strapping and stainless steel wire were used to firmly mark position on the leg and create an acoustic shadow on the ultrasound image. Anatomic landmarks were the distal patellar pole and the bony ridge on the anterior proximal tibia. After sonographic evaluation, the knee was dissected to expose the patellar tendon, which was measured using digital calipers. Intraclass correlation coefficients (ICC) were used to determine reliability of measurements between observers, where ICC >0.75 was considered good and >0.9 was considered excellent. Validity was measured using a Bland-Altman plot, which measures bias between measurement methods as well as variability of scatter. Three sonographic measurements were made by each investigator on each tendon. The length of each of the four tendons based on the mean values of sonographic measurements was 53.8 mm, 53.4 mm, 49.4 mm and 46.8 mm. The length based on visual inspection of the dissected tissue was 54.6 mm, 52.8 mm, 49.8 mm and 46.9 mm. The calculated ICC between raters was 0.96. On the Bland-Altman plot, the bias, or mean difference between sonographic and visual measures, was 0.17 mm, with a standard deviation of 0.71. The 95% limit of agreement was -1.55 to 1.22 mm. Measurement of patellar tendon length with ultrasound using adjustable surface markers and calipers is highly accurate and has good interrater reliability.

Reliability of sonographic assessment of tendinopathy in tennis elbow

OBJECTIVE

To assess the reliability and compute the minimum detectable change using sonographic scales to quantify the extent of pathology and hyperaemia in the common extensor tendon in people with tennis elbow.

MATERIALS AND METHODS

The lateral elbows of 19 people with tennis elbow were assessed sonographically twice, 1-2 weeks apart. Greyscale and power Doppler images were recorded for subsequent rating of abnormalities. Tendon thickening, hypoechogenicity, fibrillar disruption and calcification were each rated on four-point scales, and scores were summed to provide an overall rating of structural abnormality; hyperaemia was scored on a five point scale. Inter-rater reliability was established using the intraclass correlation coefficient (ICC) to compare scores assigned independently to the same set of images by a radiologist and a physiotherapist with training in musculoskeletal imaging. Test-retest reliability was assessed by comparing scores assigned by the physiotherapist to images recorded at the two sessions. The minimum detectable change (MDC) was calculated from the test-retest reliability data.

RESULTS

ICC values for inter-rater reliability ranged from 0.35 (95% CI: 0.05, 0.60) for fibrillar disruption to 0.77 (0.55, 0.88) for overall greyscale score, and 0.89 (0.79, 0.95) for hyperaemia. Test-retest reliability ranged from 0.70 (0.48, 0.84) for tendon thickening to 0.82 (0.66, 0.90) for overall greyscale score and 0.86 (0.73, 0.93) for calcification. The MDC for the greyscale total score was 2.0/12 and for the hyperaemia score was 1.1/5.

CONCLUSION

The sonographic scoring system used in this study may be used reliably to quantify tendon abnormalities and change over time. A relatively inexperienced imager can conduct the assessment and use the rating scales reliably.

Alterations of tendons in patients with diabetes mellitus: a systematic review

AIMS

To perform a systematic review of observational studies which analyse tendon alterations in patients with diabetes mellitus compared with healthy individuals.

METHODS

Data collection was performed, with no language restriction, using the databases of PubMed/Medline, BIREME, CINAHL, LILACS and Cochrane, as well as the references found in these studies. Three reviewers performed independent extractions of articles. Subsequently, these reviewers analysed the articles, focusing on their methodological quality, using the appropriate scale to evaluate observational studies from the Agency for Healthcare Research and Quality.

RESULTS

Six articles were included in the analysis. Of these, four had used ultrasonographic diagnostics, one computed tomography and one magnetic resonance imaging. The patient pool comprised 396 individuals. All the articles evaluated tendon thickness and presented heterogeneous results. Two articles stated thickening or increased volume of the tendons in diabetic people, one article did not report any alteration, the fourth failed to determine any alterations and the fifth showed thinning of the tendons. The arrangement of collagen fibrils and the presence of calcification were analysed in only one article (n = 80), showing that 88.10% (n = 68) of individuals with diabetes presented disorientation of collagen fibril arrangement, while only 10% (n = 1) of healthy individuals presented this condition. Regarding tendon calcification, the article showed diabetic individuals with higher values than healthy individuals.

CONCLUSIONS

All the articles indicated some relation between diabetes mellitus and tendon alterations in human beings, but due to methodological drawbacks, this association could not be sustained.

Intra- and interobserver reliability of quantitative ultrasound measurement of the plantar fascia

PURPOSE

To determine intra- and interobserver reliability and measurement precision of sonographic assessment of plantar fascia thickness when using one, the mean of two, or the mean of three measurements.

METHODS

Two experienced observers scanned 20 healthy subjects twice with 60 minutes between test and retest. A GE LOGIQe ultrasound scanner was used in the study. The built-in software in the scanner was used to measure the thickness of the plantar fascia (PF). Reliability was calculated using intraclass correlation coefficient (ICC) and limits of agreement (LOA).

RESULTS

Intraobserver reliability (ICC) using one measurement was 0.50 for one observer and 0.52 for the other, and using the mean of three measurements intraobserver reliability increased up to 0.77 and 0.67, respectively. Interobserver reliability (ICC) when using one measurement was 0.62 and increased to 0.82 when using the average of three measurements. LOA showed that when using the average of three measurements, LOA decreased to 0.6 mm, corresponding to 17.5% of the mean thickness of the PF.

CONCLUSIONS

The results showed that reliability increases when using the mean of three measurements compared with one. Limits of agreement based on intratester reliability shows that changes in thickness that are larger than 0.6 mm can be considered actual changes in thickness and not a result of measurement error.

Reliability and responsiveness of musculoskeletal ultrasound in subjects with and without spinal cord injury

Rehabilitation after spinal cord injury (SCI) aims to preserve the integrity of the paralyzed musculoskeletal system. The suitability of ultrasound (US) for delineating training-related muscle/tendon adaptations after SCI is unknown. The purpose of this study was to quantify within- and between-operator reliability for US and to determine its responsiveness to post-training muscle/tendon adaptations in SCI subjects. Two novice operators and one experienced operator obtained sonographic images of the vastus lateralis, patellar tendon, soleus, and Achilles tendon from seven SCI subjects and 16 controls. For control subjects, within-operator concordance (ICC [3,1]) ranged from 0.58 to 0.95 for novice operators and exceeded 0.86 for the experienced operator. Between-operator concordance (ICC [2,1]) ranged from 0.62 to 0.74. Ultrasound detected muscle hypertrophy (p < 0.05) following electrical stimulation training in subjects with SCI (responsiveness) but did not detect differences in tendon thickness. These error estimates support the utility of US in future post-SCI training studies.

Measurement issues in the sonographic assessment of tennis elbow

Sonography is increasingly being used for assessment in tennis elbow research and clinical practice, but there are a lack of data regarding its validity, reliability, and responsiveness to change for this application. Studies using the modality were reviewed to establish current levels of evidence for these measurement properties. There is reasonable evidence regarding its validity for identifying tennis elbow tendinopathy, but a lack of data addressing its reliability and responsiveness. Practical issues affecting image quality are discussed, and recommendations for further investigation are suggested, to enhance the credible use of sonography with this debilitating condition.

Association between ultrasonographic findings and bone/cartilage biomarkers in patients with early-stage knee osteoarthritis

Little is known regarding the association between ultrasonographic (US) findings and biomarkers of bone and cartilage in individuals with knee osteoarthritis (OA). We investigated (1) US findings in early-stage knee OA and (2) the association between US findings and bone/cartilage biomarkers. A population cohort aged 35-55 years (n = 106) with early-stage knee OA was investigated. US examination was performed according to European League against Rheumatism (EULAR) guidelines using a 7.5-MHz probe. Biomarkers of bone resorption (CTx-I) and formation (PINP), cartilage resorption (U-CTx-II) and synthesis (S-PIIANP), and general bone and cartilage biomarkers (OC, COMP) were assessed. The most prevalent US findings were tendon calcification, synovial thickening, and suprapatellar effusion. In women, the presence of tendon calcification and Baker's cysts could predict 36% of the variability in U-CTx-II levels. The presence of osteophytes and tendon calcification predicted up to 38% of the variability of PIIANP concentration. Defects in subchondral bone, meniscal changes, and effusion predicted up to 29% of the variability in COMP levels. Tendon calcification was related to cartilage synthesis (based on PIIANP levels) in men and to cartilage degradation (based on U-CTx-II concentrations) in women. US signs of synovitis were reflected metabolically by markers of joint tissue metabolism. Tendon calcification, synovial thickening, and effusion were common US findings in early-stage knee OA. US-detectable findings were substantially responsible for the variability in bone and cartilage biomarkers, associations reflective of the active metabolism of soft tissues in early-stage OA.