Soft tissue vibrations within one soft tissue compartment

The concept of muscle tuning suggests that vibrations of the soft tissue compartments of the leg initiated by impacts are minimized by muscular activity prior to heel-strike of heel-toe running. For the quantification of muscle tuning it has been assumed (1) that the soft tissue compartment acts as one lumped mass and (2) that vibration energy dissipation does occur within one muscle. The purpose of this study was to test these two assumptions. It was hypothesized that (H1) the movement of the soft tissue compartment is not homogeneous, (H2) the vibration frequencies for different muscles within one soft tissue compartment are different and (3) attenuation of vibration movement within one muscle does occur. Soft tissue vibrations were measured using accelerometers on four locations on the quadriceps soft tissue compartment during heel-toe running. There were differences in the peak soft tissue acceleration and time of peak acceleration between accelerometer locations. The dominant frequency was similar throughout the soft tissue compartment, however; there was an attenuation of high-frequency vibration energy between distal and proximal points overlying one muscle. This evidence suggests that accelerometer placement is important when quantifying the acceleration magnitude and timing of peak soft tissue compartment but not when estimating the resonant vibration characteristics of a soft tissue compartment. It also provides initial evidence to support the idea that vibration control through muscle tuning may be achieved through changes in energy dissipating properties within the soft tissue compartment.     

Soft tissue tumors of the penis: a review

Penile soft tissue tumors comprise 5% of tumors at this site and most have been reported as isolated case reports. The purpose of this review is to aid the practicing surgical pathologist in distinguishing penile soft tissue tumors, such as sarcomatoid squamous cell carcinoma, from other prognostically and therapeutically important entities in the differential diagnosis. Clinical presentation, management, prognosis and factors influencing behavior are reviewed. The immunohistochemical profiles and salient morphologic clues that may help distinguish penile spindle cell tumors from sarcomatoid carcinomas are evaluated. Soft tissue tumors of the penis may be classified as benign or malignant, as superficial or deep and in terms of age at presentation. All are rare. The most common benign soft tissue tumors that affect the penis are vascular neoplasms, followed by tumors of neural, myoid and fibrous origin. Among reported cases, the most frequent malignant penile soft tissue tumors are Kaposi sarcoma and leiomyosarcoma. Correctly diagnosing penile soft tissue tumors is imperative, because the biologic behavior and the clinical management of these neoplasms vary considerably. Distinguishing sarcomas from sarcomatoid carcinoma and melanoma is particularly important. Accurate diagnosis is best facilitated by consideration of all available aspects of the case, including clinical information, histopathologic findings and immunohistochemical results.     

Soft tissue tumors of the prostate: a review

Prostate cancer is a leading cause of cancer-related death in adult men. Some prostates that are suspected to be involved by prostatic adenocarcinoma or nodular prostatic hyperplasia through clinical examination and imaging studies proves on histologic examination to be a soft tissue tumor. This paper outlines the most common soft tissue tumors of the prostate and categorizes them into benign, malignant or miscellaneous. Pathologists must be aware that most, if not all, soft tissue tumors of the body may also be found in the prostate. Diagnostic immunohistochemistry is an important adjunct to histopathology for proper diagnosis and tumor subclassification.     

Primary intramuscular infestation of Echinococcus granulosus misdiagnosed as a soft tissue tumor: a case report

BACKGROUND: The occurrence of a primary intramuscular infestation of Echinococcus granulosus is extremely rare. CASE: A 70-year-old woman with primary skeletal muscle hydatidosis initially presented with a soft tissue mass. Clinical and radiologic examination revealed a huge cystic mass in the right quadriceps muscle without any visceral organ involvement. Since the differential diagnosis included a soft tissue tumor, fine needle aspiration cytology was performed, and a diagnosis of hydatid disease was made. CONCLUSION: This very rare case of primary intramuscular infestation of E granulosus was clinically misdiagnosed as a soft tissue tumor. Hydatid disease, albeit rare, should be considered in the differential diagnosis of a soft tissue mass.     

Cytological diagnosis of soft tissue tumours

Cytological diagnosis of soft tissue tumours The aims of this study were to determine the patterns of soft tissue tumours and also to try to assess the utility of fine needle aspiration cytology (FNAC) in diagnosing soft tissue tumours. Of 15 361 patients who visited the cytology diagnostic service of the Pathology Department, Medical Faculty, Addis Ababa University, 623 (4.1%) cases with a diagnosis of soft tissue tumours were retrieved from the department's records for the years 1991-96. Fifty-three soft tissue tumours (25 benign and 28 malignant tumours) with combined FNAC and surgical biopsy results were traced for cyto-histological correlations. Twenty-two out of 25 benign soft tissue tumours were correctly diagnosed, with three false cytologic diagnoses where one mesenchmal neoplasm, one haemangioma, and one haemorragic lesion were identified; and out of 28 malignant soft tissue, 23 were correctly diagnosed however, the five false cytological diagnoses were one soft tissue sarcoma, one dermatofibrosarcoma, one malignant mesenchymal neoplasm, one spindle cell neoplasm and one menechymal neoplasm. Thus, in this study a sensitivity and specificity of 88.5% and 81.5% respectively for the diagnosis of soft tissue tumours were reported. In conclusion, FNAC of soft tissue tumours is a fast, effective and reliable diagnostic tool that may help in categorizing soft tissue tumours into benign and malignant groups for clinical management.     

Interaction of stress and growth in a fibrous tissue

The influence of stress on the growth and remodeling of a soft biological tissue is considered. For this purpose, the soft tissue is idealized as a fiber network. The stress-free lengths of the fibers composing the network are not fixed as in an inert elastic solid, but are assumed to evolve as a result of growth and stress adaptation. Similarly, the topology of the fiber network may also evolve under the application of stress. A set of constitutive equations are proposed which relate the tissue stress to the deformation of the tissue as well as to its growth and microstructure. It is shown that distinctly different growth patterns which may arise during initial growth or wound healing can be modeled by the proposed mathematical analysis.     

Thick calcification from a GIST of the stomach penetrating into pericolic soft tissue - report of a case

Thick calcification is a rare presentation of gastrointestinal stromal tumor (GIST). Penetration into gastric mucosa and pericolic soft tissue has never been reported. We report a case of gastric GIST with cystic degeneration and thick calcification in an 81-year old female, who presented with hematemesis and severe abdominal pain. Thick calcification of this tumor penetrating into pericolic soft tissue was noted and successfully treated by distal gastrectomy and partial colectomy. For gastrointestinal tumors with thick calcification, even with benign behavior, surgical intervention should be considered for both oncological considerations and prevention of catastrophes like perforation or penetration into surrounding soft tissue.     

Cytopathological diagnosis of alveolar soft part sarcoma,a rare soft tissue neoplasm

S. Agarwal, R. Gupta, V. K. Iyer, S. R. Mathur and R. Ray Cytopathological diagnosis of alveolar soft part sarcoma, a rare soft tissue neoplasm Objective: Alveolar soft part sarcoma (ASPS) is a rare soft tissue neoplasm, having various morphological mimics, especially on fine needle aspiration cytology (FNAC). Because no definite immunohistochemical markers are available to aid a correct diagnosis, knowledge of the cytomorphological features is essential for correct patient management. Cytological features of five cases of ASPS are discussed, along with the ultrastructural findings available in one of them. Methods: Cytology records from 1997 to 2009 were reviewed for cases with a diagnosis of ASPS on cytology. The histology slides of the cases were also assessed for confirmation of the diagnosis. All the slides were reviewed by three pathologists. Results: There were five cases of ASPS diagnosed on FNAC. Their cytological features were noted in detail. The diagnoses in all the cases were confirmed on histology, and ultrastructural findings available in one of them were also assessed. Conclusions: The knowledge of cytological features may aid in diagnosing this rare tumour correctly on FNA smears, thus enabling correct patient management.     

Effect of adrenaline on kidney lysosome function in rats during prolonged soft tissue crushing

The total and unsedimentable activity of acid DNase, RNase, phosphatase and arylsulfatases A and B was examined in the rat kidneys during long-term compression of soft tissues in the presence of high excitability of the sympathoadrenal system. Injection of adrenalin to rats with trauma reduced the total activity of DNase, acid phosphatase and arylsulfatases A and B, particularly at the late periods of soft tissue compression, whereas the total activity of acid RNase slightly increased as compared with control. Compression of soft tissues after adrenalin preinjection was accompanied by a substantial rise of unsedimentable activity of the lysosomal enzymes under study in the kidneys. The activity of the enzymes in cytosol progressively ascended as the time of soft tissue injury increased.     

Region-specific constitutive modeling of the plantar soft tissue

Recent research has shown that hyperelastic properties of the plantar soft tissue consisting of adipose tissue and fibrous septa change from region to region. However, relatively little research has been conducted to develop analytical or computational models to describe the region-specific behavior of the plantar soft tissue. The objective of the research is to develop a region-specific constitutive model of the plantar soft tissue. Plantar soft tissue specimens were dissected from six regions [subcalcaneal (CA), sublateral (LA), subnavicular (Nav), 1st, 3rd, and 5th submetatarsal (M1, M3, M5)] from cadaveric foot samples, and a picrosirius red staining technique was used to visualize the collagen fibers in fibrous septa. The volume fractions of adipose tissue and fibrous septa and the volume fractions of the principal orientations of the fibrous septa were calculated with the intensity gradient method. Region-specific constitutive models were then developed in finite element analysis considering the microstructure of the plantar soft tissue. The hyperelastic region specific material properties of the plantar soft tissue were validated with experimental unconfined compression tests and indentation tests from the literature. The results show that the models give reasonable predictions of the stiffness of the soft tissue within a standard deviation of the tests. The region-specific constitutive models help to explain how changes in the constituents are related to mechanical behavior of the soft tissue on a region specific basis.     

The effect of perfusion on soft tissue mechanical properties: a computational model

Some simple finite element models were constructed to investigate the magnitude and character of changes in mechanical properties of very soft tissues due to the loss of perfusion. Changes in the apparent stress-strain curve were used to characterise the effect of simulated blood perfusion pressure on the engineering stress-strain curve. The results indicated that the blood to tissue volume ratio and the perfusion pressure have the strongest effect on the effective stress-strain response of a representative tissue cell. Tissue viscoelasticity increased the sensitivity of the system to perfusion pressure changes.     

An evaluation of the radiation similarity between soft biological tissue and a modified ferrosulfate dosimeter

On the basis of recent recommendations on soft biotissue composition and data concerning value of specific neutron kerma for a number of element atoms within the energy from thermal one to 29 MeV obtained were the values of electron density, effective atomic number and specific kerma of neutrons for soft biotissue and ferrosulphate dosimeter sensitized by benzoic acid. The data are proposed for practical use in radiobiological experiments.     

Experimentally observed soft‐tissue preservation near a marine brine seep

A sea urchin placed on the sea floor near an active brine seep was recovered after 13 years with detailed soft‐tissue preservation. Growth of an amorphous calcium carbonate solid with small amounts of the mineral bassanite occurred on the spines and test. The solid also exhibits striations at both the macro‐ and microscopic scales that preserve the muscle texture of the sea urchin. Such soft‐tissue replacement and mineralization could lead to exquisite fossilization. Soft‐tissue mineralization has been previously replicated in controlled laboratory conditions; however, this is the first report of the lithologic replication of soft tissues in an open marine experiment. Examples of extraordinary fossil preservation, or Lagersätten, give a distinct snapshot of the past and have led to a greater understanding of the history of life. Soft‐tissue lithification occurs in special circumstances in which local chemical conditions (often mediated by decay or bacterial factors) promote early diagenetic mineralization, the first steps of which are observed in this instance. The preservation of articulated skeletons, especially within echinoderms, is normally attributed to rapid burial, but that may not be necessary given that this urchin was at or very near the sediment–water interface for 13 years.     

Effect of rocker shoes and running speed on lower limb mechanics and soft tissue vibrations

Previous studies have shown a possible effect of running speed and the sole material of footwear on lower-limb mechanics and soft tissue vibrations, while little information has been offered concerning the influence of the shape of the footwear’s sole. The purpose of this study is to assess the effect of running speed and rocker shoes on muscular activity, ground reaction force, and soft tissue vibrations. Twenty participants performed heel-toe running with two shoes, differentiated only by their sole shape (i.e. rocker and non-rocker), at four running speeds. Ground reaction force and electromyograms of the gastrocnemius medialis and vastus lateralis were measured, and soft tissue accelerations of the same muscles were recorded with tri-axial accelerometers. A continuous wavelet transform was applied to the accelerometer’s signals to analyse them in the time-frequency domain. The rocker of the shoes did not change the muscular activations, ground reaction force, nor power of soft tissue vibrations. In opposite, increased running speed led to an augmentation of all of the measured parameters. Interestingly, running speed augmentation led to a greater increase in high frequencies component of soft tissue vibrations (25–50 Hz, 242%) than lower ones (8–25 Hz, 111%). Consequently, we indicated a 10% increase in the relative part of the high frequencies of the total power. In conclusion, although rocker shoes have shown an effect on lower-limb kinetics in some studies, no influence on soft tissue vibration is denoted. By contrast, soft tissue vibrations may be modulated by changing running speed.     

The role of the heel pad and shank soft tissue during impacts: a further resolution of a paradox

The aim of this study was to test the hypothesis that the motion of the soft tissue of the lower leg contributes significantly to the attenuation of the forces during heel impacts. To examine this, a two-dimensional model of the shank and heel pad was developed using DADS. The model contained a heel pad element and a rigid skeleton to which was connected soft tissue which could move relative to the bone. Simulations permitted estimation of heel pad properties directly from heel pad deformations, and from the kinematics of an impacting pendulum. These two approaches paralleled those used in vitro and in vivo, respectively. Measurements from the pendulum indicated that heel pad properties changed from those found in vitro to those found in vivo as relative motion of the bone and soft tissue was allowed. This would indicate that pendulum measures of the in vivo heel pad properties are also measuring the properties of the whole lower leg. The ability of the wobbling mass of the shank to dissipate energy during an impact was found to be significant. These results demonstrate the important role of both the heel pad and soft tissue of the shank to the dissipation of mechanical energy during impacts. These results provide a further clarification of the paradox between the measurements of heel pad properties made in vivo and in vitro.     

Primary giant cell tumor of soft tissue. Report of a case with fine needle aspiration cytologic and histologic findings

BACKGROUND: So-called primary giant cell tumor of soft tissue of low malignant potential is the rare soft tissue analogue of giant cell tumor of bone, occurring primarily in superficial soft tissue. To our knowledge, the cytologic findings in bulky giant cell tumor of deep soft tissue were described only once, and no further report on the subcutaneous giant cell tumor could be retrieved from the literature. CASE: A 58-year-old woman presented with a well-demarcated, 1.5-cm-diameter dermal tumor. Fine needle aspiration smears contained numerous osteoclastlike giant cells and mononuclear cells showing bland and vesicular nuclei. A small fragment of branching vasculature and 1 mitosis were found. Those cytologic findings were enough to suggest a diagnosis of giant cell tumor of soft tissue, confirmed as a deep dermal giant cell on surgical resection. CONCLUSION: Primary giant cell tumor of soft tissue of low malignant potential should be considered in the differential diagnosis of bland-looking giant cell-rich lesions. Awareness of its existence and knowledge of its cytologic features are important for a correct preoperative cytologic diagnosis.     

Soft tissue structures resisting anterior instability in a computational glenohumeral joint model

The glenohumeral joint is the most dislocated joint in the body due to the lack of bony constraints and the dependence on soft tissue for stability. The roles that various structures provide to joint function are important for understanding injury treatment and orthopaedic device design purposes. The goal of this study was to develop a computational model of the glenohumeral joint whereby joint behaviour was dictated by articular contact, ligamentous constraints, muscle loading and external perturbations. The bone structure of the computational model consisted of assembled computer tomographic images of the scapula, humerus and clavicle. The soft tissue elements were composed of forces and tension-only springs that represented muscles and ligaments. Validation of this model was achieved by comparing computational predictions to the results of a cadaveric experiment in which the relative contribution of muscles and ligaments to anterior joint stability was examined. The computational model predicted an anterior subluxation force that was similar to the cadaveric experimental results in humeral external rotation. The individual structure results showed the subscapularis to be critical to stabilisation in both neutral and external rotations, the biceps stabilised the joint in neutral but not in external rotation, and the inferior glenohumeral ligament resisted anterior displacement only in external rotation. The model's predictions were similar to the conclusions of the cadaveric experiment and the literature. Knowledge gained from this type of model could assist in further understanding the contribution of soft tissue stabilisers to joint function, pre-operative planning or the design of orthopaedic implants.     

Adipose derived stem cells and platelet rich plasma improve the tissue integration and angiogenesis of biodegradable scaffolds for soft tissue regeneration

Molecular Biology Reports - Current surgical reconstruction for soft tissue replacement involves lipotransfer to restore soft tissue replacements but is limited by survival and longevity of the fat...     

Design and evaluation of a cryogenic soft tissue fixation device -- load tolerances and thermal aspects

Mechanical studies of soft connective tissues often encounter methodological difficulties, particularly in the secure fixation of the tissues. A simple, inexpensive technique which allowed stable cryofixation of soft tissues in uniaxial loading machines was developed. The cryogenic fixation device was evaluated in terms of its fixation strength and the temperature gradients within the tested tissues. Human patellar ligaments and quadriceps tendons were tested successfully to an average failure load of 2219N (S.D. 448N) with mid-substance failures occurring in 90% of the specimens. The temperature gradients within porcine flexor and extensor tendons were determined and found to exhibit a typical diffusion profile. The fixation quality was dependent upon the initial block temperature and the desired testing time. In summary, the cryofixation device presented here is an effective tool for soft tissue fixation but the effect of this type of fixation on internal tissue temperatures and possible testing times must be acknowledged.     

A review of histomorphometric analysis techniques for assessing implant-soft tissue interface

Abstract

The success of dental implant treatment depends on the healing of both hard and soft tissues. While osseointegration provides initial success, the biological seal of the peri-implant soft tissue is crucial for maintaining the long term success of implants. Most studies of the biological seal of peri-implant tissues are based on animal or monolayer cell culture models. To understand the mechanisms of soft tissue attachment and the factors affecting the integrity of the soft tissue around the implants, it is essential to obtain good quality histological sections for microscopic examination. The nature of the specimens, however, which consist of both metal implant and soft peri-implant tissues, poses difficulties in preparing the specimens for histomorphometric analysis of the implant-soft tissue interface. We review various methods that have been used for the implant-tissue interface investigation with particular focus on the soft tissue. The different methods are classified and the advantages and limitations of the different techniques are highlighted.