Three-dimensional quantitative measurements of atrophy and fat infiltration in sub-regions of the supraspinatus muscle show heterogeneous distributions: a cadaveric study.

INTRODUCTION: Rotator cuff tears are common in the older population. Atrophy and fat infiltration develop un-evenly in torn supraspinatus (SSP) muscles leading to pre- and post-surgical complications. The purpose of the current study was twofold: first, to implement a volumetric and quantitative magnetic resonance imaging (MRI) approach to quantify the degree of muscle atrophy and fat infiltration within the SSP muscle and its four sub-regions (AS, PS, AD, and PD); second to compare 3-D MRI outcomes to the standard 2-D assessment and investigate their relationship with tear size. MATERIALS AND METHODS: Fifteen cadaveric shoulders were obtained and MRI performed. Quantitative 3-D outcomes included SSP muscle volume, fossa volume, fat-free muscle volume, and fat fraction for the whole SSP muscle and its four sub-regions. 2-D and qualitative measurements included tear size, 2-D fat infiltration using the Goutallier classification, tangent sign, and occupation ratio. RESULTS: Linear regression outcomes with tear size were not significant for both cross-sectional area (r = - 0.494, p = 0.061) and occupation ratio (r = - 0.011, p = 0.969). Tear size negatively correlated with fat-free muscle volume for both AS and PS sub-regions (AS: r = - 0.78, p < 0.001; PS: r = - 0.68, p = 0.005, respectively) while showing no significant correlation with fat fraction outcomes. AD and PD sub-regions positively correlated with tear size and fat fraction outcomes (AD: r = 0.70, p = 0.017; PD: r = 0.52, p = 0.045, respectively), while no significant correlation was observed between tear size and fat-free muscle volumes. CONCLUSION: Quantitative 3-D volumetric assessment of muscle degeneration resulted in better outcomes compared to the standard 2-D evaluation. The superficial supraspinatus muscle sub-regions primarily presented muscle atrophy, while the deep sub-regions were mainly affected by fat infiltration. 3-D assessments could be used pre-surgically to determine the best course of treatment and to estimate the muscles' regenerative capacity and function.

Influence of fat infiltration, tear size, and post-operative tendon integrity on muscle contractility of repaired supraspinatus muscle.

BACKGROUND: The purpose of this study was to evaluate the effect of fat infiltration, tear size, and post-operative tendon integrity, on post-operative contractility. METHODS: Thirty-five patients who underwent rotator cuff repair were included. The fat infiltration, tear size, and post-operative tendon integrity were evaluated by Goutallier stage, Cofield classification, and Sugaya classification, respectively. The muscle elasticity at rest and at contraction was assessed by real-time tissue elastography pre- and one-year post-operatively. We defined the difference in elasticity between at rest and at contraction as the activity value which reflects muscle contractility. RESULTS: The activity value in patients with Sugaya Type I tended to increase regardless of Cofield classification, whereas those with Sugaya Type III and IV tended to decrease. While the activity value in the patients classified as stage 1 and Type I tended to increase, patients classified as stage 2 showed decreased or constant in contractility even in those subjects classified as Type I. Stepwise multiple regression analysis showed both pre- (p = 0.004, r = -0.47) and post-operative activity values (p = 0.022, r = -0.39) to be significantly correlated only with the Goutallier stage. CONCLUSION: Multiple regression analysis indicated only the Goutallier stage was a significant independent factor for contractility of the supraspinatus muscle. Supraspinatus muscle contractility in patients classified as Types III and IV based on the Sugaya classification tended to decrease post-operatively, while patients whose contractility increased post-operatively were characterized by having a Type I tendon integrity.

Shoulder scaption is dependent on the behavior of the different partitions of the infraspinatus muscle.

PURPOSE: The purpose of this study was to investigate if the three partitions (superior, middle, and inferior partitions) of the infraspinatus muscle previously described in anatomical studies will present different behavior during scapular plane abduction (scaption) as described using shear-wave elastography, especially during initial range of motion. METHODS: Eight volunteers held their arm against gravity 15° intervals from 30° to 150° in scaption. Shear-wave elastography was implemented at each position to measure shear modulus at rest and during muscle contraction, as a surrogate for muscle stiffness, of each partition. Muscle activity was defined as the difference in stiffness values between the resting positions and those during muscle contraction (ΔE = stiffness at contraction-stiffness at rest). RESULTS: The activity value for the middle partition was 25.1 ± 10.8 kPa at 30° and increased up to 105° (52.2 ± 10.8 kPa), with a subsequent decrease at larger angle positions (p < .001). The superior partition showed a flatter and constant behavior with smaller activity values except at higher angles (p < .001). Peak activity values for the superior partition were observed at 135° (23.0 ± 12.0 kPa). Increase activity for inferior partition began at 60° and showed a peak at 135° (p < .001; 32.9 ± 13.8 kPa). CONCLUSION: Stiffness measured using shear-wave elastography in each partition of the infraspinatus muscle demonstrated different behavior between these partitions during scaption. The middle partition generated force throughout scaption, while the superior and inferior partitions exerted force at end range.

Capsular attachment of the subregions of rotator cuff muscles.

PURPOSE: This study aimed to morphologically and histologically investigate the relationship between deep subregions of the rotator cuff muscle and shoulder joint capsule as well as the relationship between the rotator cuff tendon or capsule and bony insertion. METHODS: We examined 13 shoulders of embalmed cadavers and measured the capsular attachments and footprints macroscopically. We also histologically examined the fibres in three shoulders. RESULTS: Loose attachment, which was less tight with spaced connective tissue, and firm attachment, which was tight with dense connective tissue, were found under the surface of the supraspinatus and infraspinatus. The anterior-deep and posterior-deep subregions of the supraspinatus and the middle partition and inferior partition of the infraspinatus formed firm attachments to the capsule. The mean areas of firm attachment for the anterior-deep subregion, posterior-deep subregion and middle partition were 118.8 mm2, 267.8 mm2 and 399.3 mm2, respectively, while the area of the inferior partition was small. The transverse fibres were located just lateral to the medial edge of the firm attachment area. The thick capsule had a substantial footprint. Both tendon fibres and the capsule inserted into the superior and middle facets through the attachment fibrocartilage. CONCLUSIONS: The posterior-deep subregion of the supraspinatus and middle partition of the infraspinatus evenly occupied the capsular attachment area. The transverse fibres were located just lateral to the medial edge of the firm attachment area, and the thick capsule had a substantial footprint. Both tendon fibres and the capsule inserted into the superior and middle facets through the attachment fibrocartilage.

Contractile property measurement of the torn supraspinatus muscle using real-time tissue elastography.

HYPOTHESIS: In the restoration of shoulder abduction, decreased contractility of the torn rotator cuff muscle may be a cause of a poor result. The aim of this study was to investigate the relationship between the contractile property of the torn supraspinatus muscle measured by real-time tissue elastography and the Goutallier stage as modified by Fuchs et al. METHODS: The muscular hardness of the torn supraspinatus muscle was measured in 32 patients at rest and during isometric contraction with the shoulder abducted to 60° in the scapular plane. The muscular hardness was calculated as the strain ratio. Fatty degeneration was assessed according to the modified Goutallier stage. Because the activity value (defined as the difference between the strain ratio at rest and the strain ratio during isometric contraction) estimated the contractile property of the muscle, stepwise multiple regression analysis was used to compare the activity value with age, sex, side, time from injury onset to obtaining the measurements, and modified Goutallier stage. RESULTS: The mean activity value was 0.26 ± 0.16. Fatty degeneration of the supraspinatus muscle was grade 0 in 5 patients, grade 1 in 16, grade 2 in 10, and grade 3 in 1. The activity value was significantly correlated only with the modified Goutallier stage (r = -0.78, P < .001). CONCLUSION: The contractile property of the supraspinatus muscles decreased with an increase in the modified Goutallier stage. Real-time tissue elastography can measure the contractile property of the muscles before surgery and thus may be a predictor for the resulting restoration of lost muscle function.

Functions of the subregions of the supraspinatus muscle.

The aim of this study was to investigate the functions of the six subregions of the supraspinatus muscle (SSP) determined by Kim et al. in Clin Anat 2007;20:648-655, using real-time tissue elastography (RTE). Twelve young male volunteers participated. The muscular hardness of the SSP was measured at rest and with contraction of the MMT3 in internal, neutral and external rotations. The SSP was functionally divided into five groups on the basis of the RTE results. These functional areas were roughly classified into three property groups: the anterior-superficial, anterior-middle, and anterior-deep subregions, which produce contractile force for abduction; the posterior-deep subregion, which produces contractile force for external rotation; and the posterior-superficial and posterior-middle subregions, which maintain tension. RTE was appropriate for measuring the functions of these muscular subregions. Clin. Anat. 30:347-351, 2017. © 2017 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Functions of the subregions of the infraspinatus during lateral rotation.

PURPOSE: Although recent morphological studies have revealed that the infraspinatus muscle is subdivided, the functions of the subregions remain unknown. The aim of this study is to investigate the functions of the infraspinatus subregions during lateral rotation using real-time tissue elastography (RTE). METHODS: Ten young male volunteers participated in the study. In addition to the infraspinatus subregions, the teres minor and two of six subregions of the supraspinatus determined by Kim were examined. The muscle stiffness of these subregions was measured in six conditions during lateral rotation, i.e., at rest and during manual muscle testing (MMT) 3 contraction at 0°, 35°, and 70° of lateral rotation. RESULTS: The middle and inferior subregions of the infraspinatus, teres minor, and the posterior deep supraspinatus acted as a lateral rotator. The inferior subregion of the infraspinatus was somewhat an abductor. The superior subregion of the infraspinatus was an abductor but did not contribute to the lateral rotational motion at 35° and 70° of rotation. The anterior superficial supraspinatus played an abduction role at neutral rotation but this role gradually decreased with an increasing lateral rotational angle. CONCLUSIONS: Three subregions of the infraspinatus are functionally distinct. The superior subregion contributes to abduction, the middle subregion acts as a lateral rotator, and the inferior subregion has both functions.

The functional role of the supraspinatus and infraspinatus muscle subregions during forward flexion: a shear wave elastography study.

Background: Knowledge of the morphological and functional differences in the anatomic subregions of the supraspinatus (SSP) and infraspinatus (ISP) muscles during forward flexion will provide useful information in the management of shoulder joint disorders. The purpose of this study was to investigate whether the SSP and ISP muscle subregions exhibit independent roles during forward flexion of the shoulder joint. Methods: Eight healthy male volunteers without any restriction in their shoulder joints were recruited for this study. Participants were instructed to sit on a chair with their back against the backrest. Shear modulus (kPa) was measured as a surrogate for muscle stiffness using shear wave elastography on the SSP and ISP muscle subregions. Active measurements of the nondominant arm were obtained during isometric contraction at a neutral position and every 15° intervals from 30° to 150° during forward flexion. Friedman test and Dunn's post hoc test were used to evaluate differences in measurement outcomes among angles during forward flexion in each muscle subregion. Results: Active stiffness outcomes of the anterior-middle subregion of the SSP muscle during forward flexion increased from 30° up to 45°, reaching a value of 182.4 ± 32.1 kPa (P < .001). Stiffness of the anterior-superficial subregion of the SSP muscle was highest at 30° (125.0 ± 20.6 kPa; P < .019) and linearly decreased up to 105° with increasing shoulder angle position. Stiffness of the superior, middle, and inferior subregions of ISP muscle presented a mountain-shaped trend, with peaks of 99.9 ± 23.5 kPa at 90° (P < .013), 144.2 ± 11.2 kPa at 90° (P < .013), and 122.9 ± 27.9 kPa at 105° (P < .007), respectively. Finally, the stiffness outcomes of the pectoralis major and anterior region of the deltoid muscles showed a mountain-shaped trend with peaks of 89.4 ± 23.5 kPa at 60° (P < .007) and 176.7 ± 22.9 kPa at 90° (P < .026), respectively. Conclusions: The SSP and ISP muscle subregions play a significant role during active forward flexion motion. While closely overlapped, the activity of the muscle subregions changed during the forward flexion motion range, starting with an active anterior-superficial subregion of the SSP muscle at the initial range of motion and an active inferior subregion of the ISP muscle toward midrange of motion. The SSP and ISP subregions did not demonstrate independent functional behavior during forward flexion.

The effect of a shoe lift on tensor fasciae latae length during standing with an artificial functional leg length discrepancy: An ultrasonic shear wave elastography study.

BACKGROUND: Shortening of tensor fasciae latae is one factor that causes a functional leg length discrepancy. A shoe lift has been used to correct the compensatory posture resulting from the discrepancy. Despite the potential therapeutic benefit of a shoe lift, the mechanism by which it exerts its effect is unclear. OBJECTIVE: To investigate the effect of a shoe lift on tensor fasciae latae length during standing with an artificial functional leg length discrepancy using ultrasonic shear wave elastography. METHODS: Twenty-two healthy individuals performed static standing under three conditions: drop of the pelvis and flexion of the leg resulting from fixing in the hip abduction position using a hip orthosis (functional leg length discrepancy condition); drop of the pelvis by the orthosis, but no flexion of the leg due to a shoe lift (shoe lift condition); and normal bilateral standing condition. The shear elastic modulus of tensor fasciae latae was calculated using ultrasonic shear wave elastography. RESULTS: The shear elastic modulus was significantly lower in the functional leg length discrepancy condition than in the shoe lift and normal conditions (p= 0.038). CONCLUSIONS: Using a shoe lift for the functional leg length discrepancy can result in a functional hip position that elongates tensor fasciae latae.

Elastographic Region of Interest Determination for Muscle with Fat Infiltration.

PURPOSE: Ultrasound elastography has been used to evaluate the skeletal muscle stiffness as a biomarker for sarcopenia assessment. However, there is no consensus with respect to the size and location of the region of interest in assessing such fat infiltrated muscle. The objective of this study was to determine which cross-sectional area should be measured in torn disuse muscle with fat infiltration to accurately measure muscle activity using real-time tissue elastography (RTE). METHODS: Twenty-seven patients, whose rotator cuff muscle with torn tendon was successfully repaired, were followed by programmed rehabilitation. RTE measurements of the supraspinatus muscle were obtained during muscle contraction before and one-year after surgery so that the activity value was defined as the difference between elastography measurements at rest and elastography measurements during contraction. Given that the patients with successfully repaired and completed rehabilitation showed an increased activity value, the sensitivity for three regions of interest; posterior portion of the anterior-middle subregion (AM-p), anterior region (AR), and whole cross-sectional area of the supraspinatus (whole) were compared with the number of patients showing an increase in activity values as sensitivity analysis. RESULTS: The sensitivity showing an increase in activity values was 74.1% for the AM-p area, 70.4% for the AR area, and 81.5% for the whole area. Intraclass correlation coefficient1,3 was 0.87-0.97 for the AM-p area, 0.88-0.98 for the AR area and 0.92-0.99 for the whole area. CONCLUSION: The whole cross-sectional area is suitable to measure muscle activity in muscle with fat infiltration. The results in this study will provide some beneficial information when ultrasound elastography is used for the assessment of sarcopenia muscle with fat infiltration.

Stiffness of the infraspinatus and the teres minor muscles during shoulder external rotation: An in-vitro and in-vivo shear wave elastography study.

BACKGROUND: A better understanding of the morphological and functional differences in the anatomical sub-regions of the rotator cuff muscles is critical so that appropriate surgical and rehabilitation methodologies can be implemented in patients with shoulder-related injuries. The purpose of the current study was to develop a comprehensive imaging protocol using shear-wave elastography for the infraspinatus and teres minor muscles, and investigate differences in elastic properties of three distinct infraspinatus muscle sub-regions and of the teres minor muscle. METHODS: First, we developed a protocol for probe positioning for both muscles using three cadaveric shoulders. Second, we evaluated in-vivo elastic properties [passive and active stiffness (kPa)] and excursion (mm) outcomes from these muscles during shoulder external rotation. FINDINGS: Elastic properties were significantly different among the infraspinatus muscle sub-regions and teres minor muscle. Passive stiffness decreased with increasing rotation angles except for the middle sub-region of the infraspinatus muscle which showed a decreased up to mid-range followed by an increment towards the end-range. Overall, active stiffness of the infraspinatus muscle and teres minor muscle decreased with increasing rotation angles, while that of the middle sub-region increased up to mid-range, and decreased at the end-range. INTERPRETATION: Distinct characteristics of the infraspinatus and teres minor muscles, and more importantly, of the individual sub-regions within the infraspinatus muscle call for an in-depth analysis of their morphological and functional differences. Special attention should be put into these sub-regions when performing surgical and rehabilitation procedures for patients with shoulder-related injuries.

Evaluation of the activities of the medial and lateral heads of quadratus plantae in flexion movements of the lateral four toes using ultrasound real-time tissue elastography.

Quadratus plantae (QP), one of the plantar intrinsic foot muscles, assist plantarflexion of the lesser toes. QP has medial and lateral muscle heads with different anatomical structures. The two heads of this muscle may have different roles in foot function. Ultrasound real-time tissue elastography (RTE) measurements have allowed quantitative assessment of deep-layer muscle elasticity. The purpose of this study was to determine the activity of the QP in flexion movements of the lateral four toes using RTE. Thirteen healthy subjects performed maximal voluntary contractions using a hand-held dynamometer with external belt fixation for each toe flexion movement. The elasticity of the muscles were measured using RTE during rest and flexion of each toe. The strain ratio of the muscle to that in an acoustic coupler was calculated as an index of muscle elasticity. Higher strain ratio values imply lower elasticity. The strain ratio of the medial head of QP for second toe flexion (0.10±0.11) was significantly stiffer than at rest (0.34±0.33). The strain ratios of the lateral head of QP for flexion of the second (0.32±0.19), third (0.41±0.37), fourth (0.33±0.26), and fifth (0.45±0.39) toes were significantly stiffer than at rest (1.02±0.68). These results suggest that the medial head of QP has a role in assisting second-toe flexion, and the lateral head has a role in assisting flexion of all four lateral toes.

Fat infiltration in the gluteus minimus muscle in older adults.

PURPOSE: Fat infiltration (FI) in the gluteus minimus muscle (GMin) has been reported as being restricted to the anterior part. The aim of this study was to verify whether FI is localized only to the anterior part of the GMin through the dissection of large number of elderly cadavers and to clarify the underlying mechanism of FI localized to a specific region. MATERIALS AND METHODS: Thirty-eight hips from 20 embalmed elder cadavers were dissected for verification of FI localization. The samples of three regions - the fat infiltrated region of the anterior part (FI), the region without FI (non-FI), and the posterior region - were harvested from nine hips for the histological fiber type assessment. RESULTS: The FI area was distributed at 2.6°-38° from the anterior border within the anterior part, of which function is responsible for hip extension and internal rotation and is likely reduced by disuse following aging. The number of type I fibers was lowest in FI, followed by non-FI, while the number of type I fibers was highest in the posterior. Meanwhile, the number of type II fibers was equivalent across the three regions. Atrophic type II fibers were observed in overall samples of the three regions, and grouped atrophy, which is evidence of denervation, was observed in FI and non-FI samples. Type grouping, which suggests to be reinnervated, was found in the non-FI and posterior samples but very little in the FI samples. CONCLUSION: FI in the GMin in older adults restricted to deep within the anterior part is secondary to disuse and is strongly related to impaired denervation-reinnervation process.

A case of intramuscular cysticercosis diagnosed definitively by mitochondrial DNA analysis of extremely calcified cysts.

A case of obsolete intramuscular cysticercosis diagnosed definitively by mitochondrial DNA analysis of extremely calcified cysts was reported. X-ray and computed tomography findings highly suggested cysticercosis due to Taenia solium; however, no direct evidence of cysticercosis was obtained through serological or histopathological examinations. Mitochondrial DNA analysis of a histopathological specimen confirmed the causative agent to be the Asian genotype of T. solium.

Condylar stabilizing technique for intra-articular fracture of distal radius.

I previously reported a new reduction and fixation technique for extra-articular distal radius fracture associated with osteoporosis. I developed the technique and applied it to intra-articular fracturea. I present here the technique and verify its reliability, comparing the functional results of intra-articular fracture cases to those of extra-articular cases.

Fatty degeneration of gluteus minimus muscle as a predictor of falls.

The cause of falls is multifactorial, however, hip fractures in elderly would be prevented if accidental falls are predictable. We assessed magnetic resonance images of 38 patients with groin pain after taking a fall whose fracture could not be detected by plain X-rays, and 45 patients with no episode of falls. Their ages were over 65 years. Fatty degeneration of muscles, gluteus maximus, gluteus medius, gluteus minimus, obturator externus, adductor longus, rectus femoris and iliopsoas muscles, were evaluated by Goutallier's staging. Odds ratio was calculated by a logistic regression analysis allocating dependent variable for falls and independent variables for Goutallier's stage, age and gender. The fatty degeneration of gluteus maximus muscle was generalized, while that of gluteus minimus muscle was unevenly distributed, especially in anterior area. Gluteus minimus muscle initiated its fatty degeneration earlier than gluteus medius muscle. Odds ratio of falling was 3.2 (95% confidence intervals: 1, 14, 8.94) for Goutallier' stage of the gluteus medius muscle. Fatty degeneration of gluteus medius muscle has a crucial role in providing stability of the pelvis including hip joint. Evaluating fatty streaks in the gluteus minimus muscle could help give early indication to those who have a higher risk of falling.

Condylar Stabilizing Technique with AO/ASIF Distal Radius Plate for Colles' Fracture Associated with Osteoporosis.

The author established a new reduction and fixation technique for osteoporotic distal radius fracture with a use of AO/ASIF volar distal radius plate, referring to the condylar plating technique in distal femoral fracture. This technique is performed in three steps. First, distal fixation is through the insertion of buttress pins just beneath the subchondral bone with a convergent angle of 10 degrees to the articular surface under fluoroscopic assistance. Second, the proximal limb of the plate is lined up with the radius shaft so that the fracture is reduced automatically and anatomically. Third, by rotating the proximal limb of the plate ulnarly and lifting up the ulnar border of the articular surface, the fracture is fixed less than the contralateral ulnar variance, to apply an adequate tension on the triangular fibrocartilage complex (TFCC). This method represents a valuable treatment modality for the most frequent types of unstable distal radius in elderly women.

Morphological analysis of articularis genus and involvement in muscle synchronicity with vastus intermedius / Análisis morfológico del músculo articular de la rodilla y su participación en la sincronicidad muscular con el músculo vasto intermedio

The articularis genus, which lies under the vastus intermedius, has been regarded as part of the quadriceps femoris. However, they are well known to have different function because their respective origins and insertions are mutually distinct. These muscles are considered to work almost simultaneously when the knee is extended. The electromyogram has been used to demonstrate muscle co-contraction. However, the articularis genus is deeper than other muscles. Moreover, it is difficult to analyze it by surface electromyogram. The relative proportions of muscle fiber types and the characteristics of these fiber types are important determinants of the surface electromyogram. Furthermore, biomechanical analysis of AG has remained unclear. This study investigated the ratio of muscle fiber types in these muscles. Muscle samples from seven human cadaveric specimens were used with application of immunofluorescence double staining. Results show that in the vastus intermedius and articularis genus, the percentage of Type I fibers was significantly higher than that of Type II fibers. No significant difference was found in the mean percentages of Type I and Type II fiber types. The percentages of Type I and Type II fibers in articularis genus muscle were correlated positively to the percentage in the vastus intermedius. These results suggest that similar muscle fiber compositions of these muscles might reflect their contraction during the same active phase of knee extension, despite their different functions.

El músculo articular de la rodilla, que se encuentra cubierto por el músculo vasto intermedio, se ha considerado como parte del músculo cuádriceps femoral. Sin embargo, es sabido que tienen diferentes funciones debido a que sus respectivos orígenes e inserciones son mutuamente distintas. Se considera que estos músculos trabajan de forma casi simultánea cuando la rodilla está extendida. El electromiograma se ha usado para demostrar la contracción muscular. Sin embargo, el músculo articular de la rodillas es más profundo que otros músculos. Además, es difícil analizarlo por electromiograma de superficie. Las proporciones relativas de los tipos de fibras musculares y las características de estos tipos de fibras son importantes determinantes del electromiograma de superficie. Además, el análisis biomecánico de músculo articular de la rodilla no ha sido claro. Este estudio investigó la proporción de tipos de fibras musculares en estos músculos. Se usaron muestras musculares de siete cadáveres humanos con la aplicación de doble tinción de inmunofluorescencia. Los resultados muestran que en los músculos articular de la rodilla y vasto intermedio, el porcentaje de fibras de Tipo I fue significativamente mayor que el de las fibras de Tipo II. No se encontraron diferencias significativas en los porcentajes medios de los Tipo I y Tipo II. Los porcentajes de fibras Tipo I y Tipo II en el músculo articular de la rodilla se correlacionaron positivamente con el porcentaje en el músculo vasto intermediario. Estos resultados sugieren que las composiciones de las fibras musculares similares de estos músculos podrían reflejar su contracción durante la misma fase activa de la extensión de la rodilla, a pesar de sus diferentes funciones.

Distribution of myeloid dendritic cells and plasmacytoid dendritic cells in the synovial tissues of rheumatoid arthritis.

OBJECTIVE: To examine the precise tissue distribution of dendritic cells (DC) and indoleamine 2,3-dioxygenase (IDO)-expressing cells in synovial tissue and synovial fluid (SF) from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: Synovial tissues from 30 patients with RA and 7 with OA were immunohistochemically stained for DC markers. The examined areas were classified into 5 categories based on pathobiological staging and histopathological grading systems. Myeloid DC (mDC) and plasmacytoid DC (pDC) were isolated using positive and negative magnetic sorting systems, respectively, from SF samples (7 patients with RA and 4 with OA) and synovial tissues (3 RA, 4 OA). RESULTS: mDC were mainly observed in lymphoid aggregations. pDC were scattered around perivenular infiltration areas, and small and large lymphoid aggregations in RA. The mDC/pDC ratio increased significantly, with higher grading in RA SF tissues compared to OA synovial tissues (p<0.05). IDO-immunoreactivity was detected in pDC by serial sectioning and staining of RA synovial tissues. CONCLUSION: Our results indicate that mature mDC play a central role in the RA inflammatory process. Although there were fewer pDC than mDC, the presence of IDO-positive pDC suggests a possible tolerance mechanism in RA synovial tissues. However, it is probably modest due to the marked inflammation in RA, in which mDC are dominant.

Inherited risk factors for deep venous thrombosis following total hip arthroplasty in Japanese patients: matched control study.

BACKGROUND: Inherited predisposing risk factors for deep venous thrombosis (DVT) have been clearly identified in Caucasians, but there are fewer reports evaluating these factors in the Japanese. This study was undertaken to assess the predisposing risk factors for DVT following elective total hip arthroplasty (THA) in Japanese patients. METHODS: We studied 60 patients who underwent THA. The study group consisted of 30 patients who developed DVT diagnosed by duplex sonography examination; the 30 patients who did not develop DVT served as a control group. They were matched in age, sex distribution, diagnosis (osteoarthritis secondary to dysplastic hip), and operation side(s) (bilateral or unilateral). Protein C, protein S, antithrombin III, and plasminogen activities and the plasma homocysteine level were measured. Three polymorphisms were screened for the factor V Leiden polymorphism, the factor II G20210A polymorphism, and the methylene tetrahydrofolate reductase C677T polymorphism. RESULTS: Plasma protein C activity was 82.39% +/- 14.24% in the DVT patients and 88.76% +/- 23.27% in the controls. Plasma protein C activity was significantly reduced in the study group, whereas other serologic and genetic analyses revealed no significant differences. CONCLUSIONS: Three genetic risk factors established in Caucasian patients are not valuable for evaluating DVT risk in Japanese patients. Reduced protein C activity may be a risk factor for DVT after THA.