Needle biopsy-derived myofascial tissue samples are sufficient for quantification of myofibroblast density.

Quantification of myofibroblasts is a promising method for assessing tissue properties in the field of fascia research. This is commonly performed by immunohistochemistry for α-smooth muscle actin. However, usually larger tissue samples sizes are required for quantification. The aim of this investigation was to explore whether a microscopic quantification of myofibroblasts can be conducted with fascial tissue samples derived via percutaneous needle biopsy. Fascial tissues were derived via percutaneous needle biopsy from the fascia lata of 11 persons (aged 19-40 years). Following immunohistochemistry, selected fields for photomicroscopic analysis were chosen by a Monte Carlo method based randomization procedure. On these fields, a digital quantification for the relative density of α-smooth muscle actin was attempted. The newly developed quantification method could successfully be applied in all tissue samples. The median α-smooth muscle actin density in the selected tissue samples ranged between 0% and 1.7% (median 0%, IQR 0%-0.001%). The applied protocol proved to be workable for the purpose of an estimation of the α-smooth muscle actin density in fascial tissue samples derived via percutaneous needle biopsy. Since this type of biopsy is less invasive than the commonly performed open muscle biopsy, this offers a new and useful perspective for future histological investigations of fascial tissue properties in living patients. Clin. Anat. 31:368-372, 2018. © 2018 Wiley Periodicals, Inc.

Functional in vitro tension measurements of fascial tissue - a novel modified superfusion approach.

INTRODUCTION: While two laboratory techniques are commonly used to assess the tensile properties of muscle tissue, emerging evidence suggests that the fascial components of these tissues also serve an active role in force generation. Hence, we investigated whether these techniques are sensitive for assessment of fascial micromechanics. METHODS: Force measurements on dissected fascial tissue were performed either using the classical immersion organ bath or using an improved superfusion approach simulating pulsed pharmacological triggers. Rat deep dorsal fascial strips as well as rat testicular capsule were pharmacologically challenged either with mepyramine or oxytocin. RESULTS: The classical immersion technique yielded a lower force response to mepyramine than the superfusion method (median: 367.4 vs. 555.4µN/mm(2)). Pause in irrigation before application reduced irregularities during bolus application. The superfusion approach was improved further by the following points: The high sensitivity of the superfusion method to bolus addition was voided by deviation of fluid supply during bolus addition. CONCLUSION: Although both methods demonstrated pharmacologically induced contractile responses in lumbar fascia samples, the modified superfusion method may improve force registrations of slow contracting fascial tissue and minimize artefacts of fluid application.

Contractile elements in muscular fascial tissue - implications for in-vitro contracture testing for malignant hyperthermia.

Malignant hyperthermia is a dreaded complication of general anaesthesia. Predisposed individuals can be identified using the standardised caffeine/halothane in-vitro contracture test on a surgically dissected skeletal muscle specimen. Skeletal muscle is composed of muscle fibres and interwoven fascial components. Several malignant hyperthermia-associated neuromuscular diseases are associated with an altered connective tissue composition. We analysed adjacent fascial components of skeletal muscle histologically and physiologically. We investigated whether the fascial tissue is sensitive to electrical or pharmacological stimulation in a way similar to the in-vitro contracture test for diagnosing malignant hyperthermia. Using immunohistochemical staining, α-smooth muscle actin-positive cells (myofibroblasts) were detected in the epi-, endo- and perimysium of human fascial tissue. Force measurements on isolated fascial strips after pharmacological challenge with mepyramin revealed that myofascial tissue is actively regulated by myofibroblasts, thereby influencing the biomechanical properties of skeletal muscle. Absence of electrical reactivity and insensitivity to caffeine and halothane suggests that, reassuringly, the malignant hyperthermia diagnostic in-vitro contracture test is not influenced by the muscular fascial tissue.

Clinical relevance of fascial tissue and dysfunctions.

Fascia is composed of collagenous connective tissue surrounding and interpenetrating skeletal muscle, joints, organs, nerves, and vascular beds. Fascial tissue forms a whole-body, continuous three-dimensional viscoelastic matrix of structural support. The classical concept of its mere passive role in force transmission has recently been disproven. Fascial tissue contains contractile elements enabling a modulating role in force generation and also mechanosensory fine-tuning. This hypothesis is supported by in vitro studies demonstrating an autonomous contraction of human lumbar fascia and a pharmacological induction of temporary contraction in rat fascial tissue. The ability of spontaneous regulation of fascial stiffness over a time period ranging from minutes to hours contributes more actively to musculoskeletal dynamics. Imbalance of this regulatory mechanism results in increased or decreased myofascial tonus, or diminished neuromuscular coordination, which are key contributors to the pathomechanisms of several musculoskeletal pathologies and pain syndromes. Here, we summarize anatomical and biomechanical properties of fascial tissue with a special focus on fascial dysfunctions and resulting clinical manifestations. Finally, we discuss current and future potential treatment options that can influence clinical manifestations of pain syndromes associated with fascial tissues.

The thoracolumbar fascia: anatomy, function and clinical considerations.

In this overview, new and existent material on the organization and composition of the thoracolumbar fascia (TLF) will be evaluated in respect to its anatomy, innervation biomechanics and clinical relevance. The integration of the passive connective tissues of the TLF and active muscular structures surrounding this structure are discussed, and the relevance of their mutual interactions in relation to low back and pelvic pain reviewed. The TLF is a girdling structure consisting of several aponeurotic and fascial layers that separates the paraspinal muscles from the muscles of the posterior abdominal wall. The superficial lamina of the posterior layer of the TLF (PLF) is dominated by the aponeuroses of the latissimus dorsi and the serratus posterior inferior. The deeper lamina of the PLF forms an encapsulating retinacular sheath around the paraspinal muscles. The middle layer of the TLF (MLF) appears to derive from an intermuscular septum that developmentally separates the epaxial from the hypaxial musculature. This septum forms during the fifth and sixth weeks of gestation. The paraspinal retinacular sheath (PRS) is in a key position to act as a 'hydraulic amplifier', assisting the paraspinal muscles in supporting the lumbosacral spine. This sheath forms a lumbar interfascial triangle (LIFT) with the MLF and PLF. Along the lateral border of the PRS, a raphe forms where the sheath meets the aponeurosis of the transversus abdominis. This lateral raphe is a thickened complex of dense connective tissue marked by the presence of the LIFT, and represents the junction of the hypaxial myofascial compartment (the abdominal muscles) with the paraspinal sheath of the epaxial muscles. The lateral raphe is in a position to distribute tension from the surrounding hypaxial and extremity muscles into the layers of the TLF. At the base of the lumbar spine all of the layers of the TLF fuse together into a thick composite that attaches firmly to the posterior superior iliac spine and the sacrotuberous ligament. This thoracolumbar composite (TLC) is in a position to assist in maintaining the integrity of the lower lumbar spine and the sacroiliac joint. The three-dimensional structure of the TLF and its caudally positioned composite will be analyzed in light of recent studies concerning the cellular organization of fascia, as well as its innervation. Finally, the concept of a TLC will be used to reassess biomechanical models of lumbopelvic stability, static posture and movement.

Active fascial contractility: Fascia may be able to contract in a smooth muscle-like manner and thereby influence musculoskeletal dynamics.

Dense connective tissue sheets, commonly known as fascia, play an important role as force transmitters in human posture and movement regulation. Fascia is usually seen as having a passive role, transmitting mechanical tension which is generated by muscle activity or external forces. However, there is some evidence to suggest that fascia may be able to actively contract in a smooth muscle-like manner and consequently influence musculoskeletal dynamics. General support for this hypothesis came with the discovery of contractile cells in fascia, from theoretical reflections on the biological advantages of such a capacity, and from the existence of pathological fascial contractures. Further evidence to support this hypothesis is offered by in vitro studies with fascia which have been reported in the literature: the biomechanical demonstration of an autonomous contraction of the human lumbar fascia, and the pharmacological induction of temporary contractions in normal fascia from rats. If verified by future research, the existence of an active fascial contractility could have interesting implications for the understanding of musculoskeletal pathologies with an increased or decreased myofascial tonus. It may also offer new insights and a deeper understanding of treatments directed at fascia, such as manual myofascial release therapies or acupuncture. Further research to test this hypothesis is suggested.