The Cause of Pressure Sores
J G Webster in Prevention of Pressure Sores, 2019
Skeletal muscle constitutes about 40% of the total body weight in man (Heistad and Abboud 1974). Muscle is surrounded and penetrated by layers of fibrous, avascular connective tissue called deep fascia. At rest the total blood flow through muscle is about 1 1/min; strenuous exercise increases this flow up to 25 1/min. Blood flow to muscle is determined by arterial pressure and vascular resistance in muscle. Studies in animals have shown that muscle and subcutaneous tissue are more susceptible to pressure-induced injury than the epidermis (Daniel et al 1981). Harman (1948) demonstrated that muscle is extremely sensitive to ischemia and that degeneration begins after 4 h of ischemia. Muscle fibers degenerate after exposure to contact pressure of 60 to 70 mm Hg for 1 to 2 h (Kosiak 1959). Muscle has a high tensile strength because of its fibers but it has a poor tolerance for compression and angulation (Torrance 1983).
Fascial Syndromes
Kohlstadt Ingrid, Cintron Kenneth in Metabolic Therapies in Orthopedics, Second Edition, 2018
While anatomy books like to divide fascia into discrete units and aggregates, it is vital to remember that all these parts, pieces and layers are part of one system. Starting just under the skin with the more superficial or areolar layer to the deep fascia or fascia profunda. The deep fascia comprises all the layers that interact with the musculoskeletal body (Figure 21.2). The deep fascia is highly organized and very much like an elastic, full-length body stocking – the innermost layer peeling away to form an epimysium, a pocket around each muscle. These epimysial pockets are free to glide due to hyaluronan [5]. This layer continues to the bundled perimysium, down to each individual muscle fiber wrapped in its own endomysium. This honeycomb arrangement allows for load sharing among the individual myofibers. Electron microscope studies have also revealed collagen fibers running in a more perpendicular fashion, creating a longitudinal network through the epimysium to the adjacent antagonistic muscle [16]. Other imaging studies clearly show the collagen fibers getting smaller and smaller, going all the way down to and through individual cell walls [17].
General Anatomy
Gene L. Colborn, David B. Lause in Musculoskeletal Anatomy, 2009
The deep fascia is a variably thick, fibrous layer of connective tissue which lies deep to the superficial fascia, investing the muscles of the limbs and the body wall. This fascia is thickened in some parts of the body to form sites of attachment for the origins or insertions of skeletal muscles, and is often continuous with the connective tissue which invests most muscles. In addition, the limbs are divided into muscle compartments by the attachment of deep fascial septae (plural of septum: partitions) to bones.
Immune-cell infiltration in high-grade soft tissue sarcomas; prognostic implications of tumor-associated macrophages and B-cells
Published in Acta Oncologica, 2023
Helena Nyström, Mats Jönsson, Mef Nilbert, Ana Carneiro
High-grade tumors were defined as grade 3–4, corresponding to grade 3 in the Féderation Nationale des Centers de Lutte Contre le Cancer (FNCLCC) grading system. In Scandinavia, prognostication of STS is based on the combination of the SING- factors, i.e., size >8 cm, vascular invasion, necrosis and growth pattern. Necrosis was defined as the presence of amorphous cellular debris, typically associated with a neutrophil polynuclear response, and was dichotomized as present/absent. Vascular invasion was defined as tumor cells surrounded by an endothelial lining with tumor cells required to be adherent to the luminal aspect of the vessel wall or associated with adherent fibrin, red blood cells or leukocytes, and was classified as absent/present. Depth was defined in relation to deep fascia and was classified as subcutaneous/deep. Growth pattern is defined as either pushing or infiltrative. Clustering of CD20+ lymphocytes within the tumor area was noted when present. Patient data and tumor characteristics are summarized and presented in Table 1.
The superficial peroneal neurocutaneous flap: a cadaveric study
Published in Journal of Plastic Surgery and Hand Surgery, 2023
Thepparat Kanchanathepsak, Katanyata Kunsook, Wasit Panoinont, Chinnawut Suriyonplengsaeng, Sorasak Suppaphol, Ittirat Watcharananan, Panithan Tuntiyatorn, Tulyapruek Tawonsawatruk
To ensure that the vascularity of the flap was provided by the paraneural vessels, and the subcutaneous layer was nourished by neurocutaneous perforators that received blood supply from the perforating branches of the dorsalis pedis artery, the proximally based SPNC flap was harvested before methylene blue injection. The deep fascia was included while the paratenon was left intact during flap dissection. The advantage of deep fascia inclusion is that it helps to protect the neurovascular axis while facilitating dissection [3]. The procedure correlates with that used in our previous study, performed on the upper extremities [23]. In this study, while numerous proximally perforating branches of the dorsalis pedis artery were found 1 cm distal to the anterior ankle joint line, the average distance was calculated as 1.51 cm along the same direction. In addition, to increase the mobility of the flap, the extensor retinaculum was proximally dissected to identify the perforating branches of the anterior tibialis vessel to create the proximal pivot point and long pedicle to cover the lower leg area. These perforator findings are consistent with a previous study that reported branching, at approximately 4 cm proximal to the intermalleolar line [11,24]. However, in this study, we focused on the proximal perforating branch of the dorsalis pedis artery, to avoid injury to the extensor retinaculum. Usually, if the donor site defect is unable to primary closure, it would be cover by split thickness skin graft.
Progressive subcutaneous emphysema of unknown origin: a surgical dilemma
Published in Acta Chirurgica Belgica, 2019
Lynn De Roeck, Lauranne Van Assche, Veronique Verhoeven, Ina Vrints, Jana Van Thielen, Thierry Tondu, Filip Thiessen
Clinical examination showed subcutaneous crepitations and tenderness all over the left arm and axilla. There was no discoloration of the skin or development of blisters. Sensation of the limb was normal and there was no loss of function. Pulsations were clearly palpable and capillary refill time was normal. The patient was clinically stable and underwent a series of investigations. Inflammatory parameters were slightly elevated with a leukocytosis of 11.6 x 109/L and C-reactive protein of 37.2 mg/L. Blood cultures were taken and intravenous broad-spectrum antibiotics (amoxicillin/clavulanic acid and clindamycin) were started. Radiography showed overt SE spreading from the left arm towards the axilla, without any signs of pneumothorax, fracture or osteolysis (Figure 1). On magnetic resonance imaging (MRI) of the arm, SE and inflammation of the superficial and deep fascia were noted, without muscle involvement. An additional computed tomography (CT) scan was performed and excluded pneumothorax and pneumomediastinum. Progression of the SE towards the base of the neck and anterior thorax was noted (Figure 2).
Related Knowledge Centers
- Dense Connective Tissue
- Fascia
- Joint Capsule
- Muscle
- Tendon
- Aponeurosis
- Ligament
- Fascial Compartment
- Retinaculum
- Septum