Ultrasound evaluation in combination with finger extension force measurements of the forearm musculus extensor digitorum communis in healthy subjects

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the usefulness of an ultrasound-based method of examining extensor muscle architecture, especially the parameters important for force development. This paper presents the combination of two non-invasive methods for studying the extensor muscle architecture using ultrasound simultaneously with finger extension force measurements.</p> <p>Methods</p> <p>M. extensor digitorum communis (EDC) was examined in 40 healthy subjects, 20 women and 20 men, aged 35–73 years. Ultrasound measurements were made in a relaxed position of the hand as well as in full contraction. Muscle cross-sectional area (CSA), pennation angle and contraction patterns were measured with ultrasound, and muscle volume and fascicle length were also estimated. Finger extension force was measured using a newly developed finger force measurement device.</p> <p>Results</p> <p>The following muscle parameters were determined: CSA, circumference, thickness, pennation angles and changes in shape of the muscle CSA. The mean EDC volume in men was 28.3 cm³and in women 16.6 cm³. The mean CSA was 2.54 cm²for men and 1.84 cm²for women. The mean pennation angle for men was 6.5° and for women 5.5°. The mean muscle thickness for men was 1.2 cm and for women 0.76 cm. The mean fascicle length for men was 7.3 cm and for women 5.0 cm. Significant differences were found between men and women regarding EDC volume (p < 0.001), CSA (p < 0.001), pennation angle (p < 0.05), muscle thickness (p < 0.001), fascicle length (p < 0.001) and finger force (p < 0.001). Changes in the shape of muscle architecture during contraction were more pronounced in men than women (p < 0.01). The mean finger extension force for men was 96.7 N and for women 39.6 N. Muscle parameters related to the extension force differed between men and women. For men the muscle volume and muscle CSA were related to extension force, while for women muscle thickness was related to the extension force.</p> <p>Conclusion</p> <p>Ultrasound is a useful tool for studying muscle architectures in EDC. Muscle parameters of importance for force development were identified. Knowledge concerning the correlation between muscle dynamics and force is of importance for the development of new hand training programmes and rehabilitation after surgery.</p

Ultrasound Examination in Infant Clubfoot with Special Emphasis on the Talonavicular and the Calcaneocuboid Joints

The purpose of the study was to develop an ultrasound (US) protocol for evaluating congenital clubfoot pathoanatomy before and during early treatment. By using 3 easily defined and reproducible US projections the talonavicular and the calcaneocuboid joints were assessed. Normal configurations of the relationships at these joints were obtained by investigating 54 healthy babies at the ages of 0, 4, 7 and 12 months. Variations in clubfoot pathoanatomy before treatment are described in 22 children with 30 clubfeet. Morphological changes taking place during early clubfoot treatment were assessed by following two differently treated groups of clubfeet with US and clinical investigations in the neonatal period, after 2-3 months of non-surgical treatment and 1-2 months post-surgically. Seven children (9 clubfeet, Group A) were treated with the Ponseti method with serial casting and 14 children (19 clubfeet, Group B) were treated with an adjustable plexidur splint and intensive physiotherapy (the Copenhagen method). Intra- and inter-observer agreement was assessed by two investigators examinating 17 clubfeet by US independently. The clubfeet showed medial displacement of the navicular, significant shorter medial malleolus-navicular distance (MM-N distance), and medial displacement of the cuboid compared with controls. After 2-3 months of non-surgical treatment the MM-N distance had increased significantly more in the Group A feet. The Group B feet required more extensive surgery (posterior or posteriomedial release in 13 feet) to obtain the same degree of correction as the Group B feet (tenotomy of the Achilles tendon). Inter-observer agreement expressed as kappa values were 0.70 for navicular displacement, 0.68 for talar head pointing laterally and 0.36 for medial deviation of the talar head, 1.00 indicating full agreement and 0.00 representing random agreement. Conclusions: Important aspects of clubfoot pathoanatomy can reliably be evaluated using US. Ultrasound can play an important role in the treatment of clubfoot in monitoring and evaluating the effects of treatment. It can also be used as an aid in teaching

Repeatability of sonographic measurements in clubfeet

Purpose: To assess the intra- and interobserver agreement of ultrasound assessment of clubfoot patho-anatomy in early childhood. Material and Methods: Seventeen clubfeet in 12 children were sequentially scanned by 2 examiners and repeat assessments were carried out independently. Three well-defined imaging planes were chosen to evaluate navicular displacement: the medial malleolus-navicular (MM-N) distance, soft tissue thickness, talar deformity and the calcaneocuboid (C-C) distance. Intra- and interobserver agreement was analysed using Cohen's kappa for the discrete variables and by Bland-Altman's graphic technique for measurements. Results: Kappa values for intra-observer agreement were 0.82 for navicular displacement, 0.93 for "talar head pointing laterally", and 0.70 for medial deviation of the talar neck. The corresponding interobserver kappa values were 0.70, 0.68, and 0.36. The mean difference between the two observers for the MM-N distance was 0.42+/-3.0 mm and for the soft tissue thickness 0.35+/-2.0 mm; the C-C distance showed a mean interobserver distance of 0.0+/-2.8 mm. Conclusion: The imaging planes used to study the talo-navicular and calcaneo-cuboid relationships are reproducible and relatively easy to learn. Intra- and interobserver assessments were acceptable for MM-N distance, soft tissue thickness, navicular displacement and "talar head pointing laterally", but questionable for the C-C distance and medial deviation of the talar neck

Dual energy CT findings in gout with rapid kilovoltage-switching source with gemstone scintillator detector

BackgroundA definite diagnosis of gout requires demonstration of monosodium urate crystals in synovial fluid or in tophi, which in clinical practice today seldom is done. Dual energy CT (DECT) has repeatedly been shown to be able to detect monosodium urate crystals in tissues, hence being an alternative method to synovial fluid microscopy. The vast majority of these studies were performed with CT scanners with two X-ray tubes. In the present study we aim to investigate if and at what locations DECT with rapid kilovoltage-switching source with gemstone scintillator detector (GSI) can identify MSU crystals in patients with clinically diagnosed gout. We also performed a reliability study between two independent readings.MethodsPatients with new or established gout who had been examined with DECT GSI scanning of the feet at Sahlgrenska University Hospital, Molndal between 2015 and 2018 were identified. Their medical records were sought for gout disease characteristics using a structured protocol. Urate deposits in MTP1, MTP 2-5, ankle/midfoot joints and tendons were scored semiquantatively in both feet and presence of artifacts in nail and skin as well as beam hardening and noise were recorded. Two radiologists performed two combined readings and scoring of the images, thus consensus was reached over the scoring at each occasion (Espeland et al., BMC Med Imaging. 2013;13:4). The two readings were compared with kappa statistics.ResultsDECT GSI could identify urate deposits in the feet of all 55 participants with gout. Deposits were identified in the MTP-joints of all subjects but were also present in ankle/midfoot joints and tendons in 96 and 75% respectively. Deposition of urate was predicted by longer disease duration (Spearman's Rho 0.64, p &lt;.0001) and presence of tophi (p =0.0005). Artifacts were common and mostly found in the nails (73%), a minority displayed skin artifacts (31%) while beam hardening and noise was rare. The agreement between the two readings was good (&lt;Kappa&gt;=0.66, 95% CI=0.61-0.71).ConclusionThe validity of DECT GSI in gout is supported by the identification of urate in all patients with clinical gout and the good correlations with clinical characteristics. The occurrence of artifacts was relatively low with expected locations