The purpose of this study was to investigate the site- and sex-differences in the morphological and mechanical properties of the plantar fascia (PF) in humans. The thickness and shear wave velocity ...(SWV) of PF at five different sites between the medial calcaneal tubercle and the second toe were measured for 40 healthy young participants (20 males and 20 females) using supersonic shear imaging (SSI). The thickness and SWV measurements were highly repeatable (ICC ≥ 0.93). The proximal sites of PF around the calcaneal attachment were significantly thicker and stiffer (higher SWV values) than the middle and distal sites (p < 0.05). In addition, females had significantly thinner PF in proximal and middle sites than males, while being significantly stiffer in regardless of the sites, compared with males (p < 0.05). The results of the present study partly support previous findings on the site- and sex-differences in PF morphology, and further reveal inhomogeneity and sex-specificity of PF stiffness. The present study widely opens the possibility of evaluating PF functions in vivo.
Traditionally, surgical training meant on-the-job training with live patients in an operating room. However, due to advancing surgical techniques, such as minimally invasive surgery, and increasing ...safety demands during procedures, human cadavers have been used for surgical training. When considering the use of human cadavers for surgical training, one of the most important factors is their preservation. In this review, we summarize four preservation methods: fresh-frozen cadaver, formalin, Thiel’s, and saturated salt solution methods. Fresh-frozen cadaver is currently the model that is closest to reality, but it also presents myriad problems, including the requirement of freezers for storage, limited work time because of rapid putrefaction, and risk of infection. Formalin is still used ubiquitously due to its low cost and wide availability, but it is not ideal because formaldehyde has an adverse health effect and formalin-embalmed cadavers do not exhibit many of the qualities of living organs. Thiel’s method results in soft and flexible cadavers with almost natural colors, and Thiel-embalmed cadavers have been appraised widely in various medical disciplines. However, Thiel’s method is relatively expensive and technically complicated. In addition, Thiel-embalmed cadavers have a limited dissection time. The saturated salt solution method is simple, carries a low risk of infection, and is relatively low cost. Although more research is needed, this method seems to be sufficiently useful for surgical training and has noteworthy features that expand the capability of clinical training. The saturated salt solution method will contribute to a wider use of cadavers for surgical training.
Long‐distance running (LDR) can induce transient lowering of the foot arch, which may be associated with mechanical fatigue of the plantar fascia (PF). However, this has not been experimentally ...tested in vivo. The purpose of this study was to test our hypothesis that LDR induces transient and site‐specific changes in PF stiffness and morphology and that those changes are related to the lowering of the foot arch. Ten male recreational long‐distance runners and 10 untrained men were requested to run overground for 10 km. Before and after running, shear wave velocity (SWV: an index of soft tissue stiffness) and thickness of PF at three different sites from its proximal to distal end were measured using supersonic shear imaging and B‐mode ultrasonography. Foot dimensions including the navicular height were measured using a three‐dimensional foot scanner. SWV at the proximal site of PF and navicular height was significantly decreased in both groups after running, with a higher degree in untrained men (−21.9% and −14.1%, respectively) than in runners (−4.0% and −6.3%, respectively). The relative change (%Δ) in SWV was positively correlated with %Δnavicular height in both groups (r = .69 and r = .65, respectively). Multiple regression analysis revealed that %ΔSWV at the proximal site solely explained 72.7% of the total variance in %Δnavicular height. It is concluded that LDR induces transient and site‐specific decreases in PF stiffness. These results suggest that the majority of running‐induced lowering of the foot arch is attributable to the reduction of PF stiffness at the proximal site.
Human steady-state locomotion modes are symmetrical, leading to symmetric mechanical function of human feet in general; however, track distance running in a counterclockwise direction exposes the ...runner's feet to asymmetrical stress. This may induce asymmetrical adaptation in the runners' foot arch functions, but this has not been experimentally tested. Here, we show that the plantar fascia (PF), a primary structure of the foot arch elasticity, is stiffer for the left than the right foot as a characteristic of runners, via a cross-sectional study on 10 track distance runners and 10 untrained individuals. Shear wave velocity (index of tissue stiffness: SWV) and thickness of PF and foot dimensions were compared between sides and groups. Runners showed higher PF SWV in their left (9.4 ± 1.0 m/s) than right (8.9 ± 0.9 m/s) feet, whereas untrained individuals showed no bilateral differences (8.5 ± 1.5 m/s and 8.6 ± 1.7 m/s, respectively). Additionally, runners showed higher left to right (L/R) ratio of PF SWV than untrained men (105.1% and 97.7%, respectively). PF thickness and foot dimensions were not significantly different between sides or groups. These results demonstrate stiffer PF in the left feet of runners, which may reflect adaptation to their running-specific training that involves asymmetrical mechanical loading.
The iliotibial band (ITB) is the lateral thickening of the fascia lata. The ITB has been extensively studied for its relevance to injury, but not much is known about its elastic properties. We aimed ...to investigate the site- and joint angle-dependence of ITB elasticity. We tested twelve healthy males (22–30 years; in vivo) and twelve male cadavers (69–93 years; cadaver). The Young’s modulus of the ITB was measured in the longitudinal direction at five sites (over the proximal, middle, and distal bellies of the vastus lateralis (VL), superior border of the patella, and between femur and tibia) of the right limb, by ultrasound shear wave elastography (in vivo) and the tensile test (cadaver). Joint angle-dependence was also studied for nine different positions (knee angles at 0, 25, 90˚ x hip angles at 0, 40, 90˚) (in vivo). Over VL, the ITB was more compliant at the distal (17.6–190.1 kPa; in vivo, 219.4 ± 68.8 MPa; cadaver, mean ± SD) than other sites (24.2–221.4 kPa, 337.9–362.7 MPa). The ITB at the superior border of the patella and between femur and tibia was stiffer in vivo (31.8–271.8 and 50.9–208.8 kPa), while it was more compliant in cadavers (113.4 ± 63.7 and 130.4 ± 73.7 MPa), compared to other sites. The ITB became stiffer associated with increasing hip extension angle and knee flexion angle, and the hip remarkably affecting the values regardless of site (in vivo). Our findings have clinical significance with respect to the site- and joint angle-dependence of ITB-related overuse injury.
Abstract
Cerebrospinal fluid (CSF) leakage is a rare but severe complication during dacryocystorhinostomy (DCR). Understanding the details of the anatomy of the lacrimal drainage system and skull ...base is essential to avoid this complication. We examined the positional relationship between the lacrimal sac and skull base using 16 cadavers (22 sides) and using computed tomographic images taken in 81 patients (81 sides). Consequently, the frontal sinus intervened between the lacrimal sac and skull base in 81.8–90.1% of cases. The lacrimal sac fundus and posterior lacrimal crest were far from the skull base/cribriform plate, and the skull base above the lacrimal sac was considerably thick. These results indicate that the risk of skull base injury and consequent CSF leakage during DCR is extremely low. However, surgeons should be cautious of this complication by indirect injury due to a twisting movement of a bone rongeur applied to the maxillary bone during creation of a bony window in patients with no interposition of the frontal and ethmoid sinuses between the lacrimal sac and skull base.
The human triceps surae (two gastrocnemii and soleus) has aponeuroses in the proximal and distal aspects, the latter of which insert into the calcaneus by sharing the common Achilles tendon. These ...tendinous tissues are known to have elasticity and upon muscle contraction the aponeurosis is stretched both longitudinally (along the muscle's line of action) and transversely. Higher aponeurosis transverse deformability has been documented, but there is a paucity of information on the morphology and mechanical properties of human aponeurosis. This study aimed to identify morphological and mechanical characteristics of the human triceps surae aponeuroses. Twenty-five triceps surae muscle-tendon units were procured from 13 human donors (formalin fixed, 6 males, 7 females) aged 67-91 years. Specimens of aponeuroses were excised from the eight regions (posterior and anterior regions of the gastrocnemius medialis and lateralis, medial and lateral parts of soleus; proximal, middle, and distal sites each, 2-4 cm × 2-4 cm). Aponeurosis thickness was measured using a digital caliper. Uniaxial tensile tests were implemented to determine the mechanical properties of specimens loaded longitudinally (along the muscle's line of action) and transversely. The aponeurosis thickness showed significant differences between muscles and sites, while Young's modulus showed direction-dependent (longitudinal vs. transverse) differences within sites. Results show different morphology and mechanical properties of aponeuroses between synergist muscles. The reason for site-dependent differences in stiffness is due to a reduced aponeurosis thickness rather than a reduction in the material property. The anisotropic elastic feature (differences between longitudinal and transverse directions) of the aponeuroses was more pronounced than previous in vivo findings, suggesting inherent material design of the aponeurosis that matches three-dimensional contractile behavior of muscle fibers.
Sprengel's deformity is a congenital abnormality of the shoulder girdle. Because scapular retraction, such as the Green procedure, is usually performed during childhood to improve esthetics and ...shoulder function, Sprengel's deformity is rarely found in older patients.
We presented a unique case of a Japanese female cadaver with Sprengel's deformity at the age of 80 years. Anatomical dissection and radiological imaging revealed musculoskeletal anomalies associated with Sprengel's deformity, including Klippel-Feil syndrome, presence of an omovertebral bone, and absence of the trapezius muscle. In addition, bilateral cervical ribs were in contact with the brachial plexus. These anomalies may lead to numbness, pain, and limited range of motion of the neck and upper girdle with aging.
Because most adult patients with Sprengel's deformity experience neck pain and limited movement of the shoulder, the presented case is a rare case of neglected Sprengel's deformity in an 80-year-old cadaver.
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The liposome–protamine–DNA complex (LPD) is an effective cationic carrier of various nucleic acid constructs such as plasmid DNA and small interfering RNA (siRNA). Hyaluronic acid ...coated on LPD (LPDH) reduces cytotoxicity and maintains the silencing effect of LPD-encapsulated siRNA. Herein, we aim to develop LPD- or LPDH-containing spray-freeze-dried particles (SFDPs) for therapeutic delivery of siRNA to the lungs. LPD- or LPDH-containing SFDPs (LPD- or LPDH-SFDPs) were synthesized and their structure and function as gene carriers were evaluated using physical and biological methods. The particle size of LPDH, but not of LPD, was constant after re-dispersal from the SFDPs and the amount of siRNA encapsulated in LPDH was larger than that in LPD after re-dispersal from the SFDPs. The in vitro pulmonary inhalation properties of LPDH-SFDPs and LPD-SFDPs were almost the same. The cytotoxicity of LPDH-SFDPs in human umbilical vein endothelial cells (HUVEC) was greatly decreased compared with that of LPD-SFDPs. In addition, Bcl-2 siRNA in LPDH-SFDPs had a significant gene silencing effect in human lung cancer cells (A549), whereas Bcl-2 siRNA in LPD-SFDPs had little effect. These results indicate that compared with LPD, LPDH is more useful for developing SFDPs for siRNA pulmonary inhalation.
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