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Journal of Applied Physiology... May 2019This review, the first in a series of minireviews on the passive mechanical properties of skeletal muscles, seeks to summarize what is known about the muscle... (Review)
Review
This review, the first in a series of minireviews on the passive mechanical properties of skeletal muscles, seeks to summarize what is known about the muscle deformations that allow relaxed muscles to lengthen and shorten. Most obviously, when a muscle lengthens, muscle fascicles elongate, but this is not the only mechanism by which muscles change their length. In pennate muscles, elongation of muscle fascicles is accompanied by changes in pennation and changes in fascicle curvature, both of which may contribute to changes in muscle length. The contributions of these mechanisms to change in muscle length are usually small under passive conditions. In very pennate muscles with long aponeuroses, fascicle shear could contribute substantially to changes in muscle length. Tendons experience moderate axial strains even under passive loads, and, because tendons are often much longer than muscle fibers, even moderate tendon strains may contribute substantially to changes in muscle length. Data obtained with new imaging techniques suggest that muscle fascicle and aponeurosis strains are highly nonuniform, but this is yet to be confirmed. The development, validation, and interpretation of continuum muscle models informed by rigorous measurements of muscle architecture and material properties should provide further insights into the mechanisms that allow relaxed muscles to lengthen and shorten.
Topics: Aponeurosis; Humans; Muscle Contraction; Muscle, Skeletal; Tendons
PubMed: 30571291
DOI: 10.1152/japplphysiol.00673.2018 -
Indian Journal of Plastic Surgery :... Dec 2023Bulldog scalp syndrome or cutis verticis gyrata (CVG) is a rare cutaneous disorder with an incidence of just 0.026 to 1 per 100,000 population and cosmetic problems...
Bulldog scalp syndrome or cutis verticis gyrata (CVG) is a rare cutaneous disorder with an incidence of just 0.026 to 1 per 100,000 population and cosmetic problems should not be ignored as they can affect the quality of life of patients in social and psychological aspects. In CVG the scalp thickens to form folds resembling sulci and gyri just as the skin fold of bulldog. It is a clinical diagnosis with various etiologies. It is classified as primary essential or nonessential and secondary CVG. It can manifest with symptoms ranging from mild to severe intensity. Cosmetic problems are the major concern that can affect patients' social and psychological health. If the folds are heavy, they can cause mass symptoms. Thus, surgery remains the definitive treatment option for improving the cosmetic appearance. Both our cases have different etiologies, however, were managed surgically with removal of skin folds (gyrae) and scoring of aponeuroses of the scalp followed by stretching of the scalp and closure to improve appearance. The surgical team as well as patients were satisfied with the appearance of the scalp after healing. CVG though a rare disease with various etiologies is a benign condition with good prognosis with no reports of malignant transformation so far.
PubMed: 38105879
DOI: 10.1055/s-0043-1776897 -
Hand Clinics Aug 2018Needle aponeurotomy is an effective, minimally invasive treatment for metacarpophalangeal and interphalangeal joint contractures caused by Dupuytren disease. Multiple... (Review)
Review
Needle aponeurotomy is an effective, minimally invasive treatment for metacarpophalangeal and interphalangeal joint contractures caused by Dupuytren disease. Multiple joints and digits can be safely treated in 1 session. Needle aponeurotomy is more cost-effective and has a significantly lower complication rate compared with open fasciectomy and collagenase injections. Recurrence rates are higher compared with open fasciectomy and collagenase injections. Patient satisfaction rates are high following needle aponeurotomy; the single clinic visit required and the minimal downtime after treatment are advantages unique to this procedure compared with other treatment modalities, including open fasciectomy, dermatofasciectomy, collagenase injections, and lipofilling.
Topics: Adipose Tissue; Ambulatory Surgical Procedures; Anesthetics, Local; Aponeurosis; Contraindications, Procedure; Dupuytren Contracture; Fibroma; Glucocorticoids; Humans; Injections, Intralesional; Minimally Invasive Surgical Procedures; Needles; Orthopedic Procedures; Patient Satisfaction; Postoperative Care; Postoperative Complications; Preoperative Care; Quality-Adjusted Life Years; Recurrence; Triamcinolone; Ultrasonography, Interventional
PubMed: 30012293
DOI: 10.1016/j.hcl.2018.03.003 -
The Journal of Hand Surgery Jun 2018To evaluate the thumb dorsal aponeurosis anatomy. Consideration of structural differences between the fingers and thumb will provide an improved clinical understanding...
PURPOSE
To evaluate the thumb dorsal aponeurosis anatomy. Consideration of structural differences between the fingers and thumb will provide an improved clinical understanding of the thumb dorsal aponeurosis anatomy.
METHODS
Ten fresh cadaver hands from 5 patients with an average age of 31.6 (range, 22-41) years were dissected. The thenar muscles were identified and insertion sites were documented. The fibers of the dorsal aponeurosis and contributions were identified.
RESULTS
The flexor pollicis brevis superficial head contributed to the radial fibers of the dorsal aponeurosis in 8 specimens and contributed to the deep head in 1 specimen. The abductor pollicis brevis provided fibers to the radial dorsal aponeurosis in all 10 specimens. The oblique and transverse heads of the adductor pollicis contributed to the ulnar dorsal aponeurosis in 8 and 9 hands, respectively. The fibers of the intrinsic apparatus were composed of 3 major types: transverse, oblique, and long.
CONCLUSIONS
This investigation provides a detailed anatomic study of the dorsal aponeurosis of the thumb with observation of both intrinsic and extrinsic contributions.
CLINICAL RELEVANCE
Understanding the anatomy of the dorsal aponeurosis of the thumb remains important not only for evaluation of the classic Stener lesion, but also for the appropriate treatment of deformity, contracture, and neuromuscular disorders involving the thumb.
Topics: Adult; Aponeurosis; Cadaver; Humans; Male; Muscle, Skeletal; Tendons; Thumb; Young Adult
PubMed: 29361325
DOI: 10.1016/j.jhsa.2017.11.009 -
Hand Clinics Aug 2018Treatment of recurrent Dupuytren disease is challenging. Multiple options exist, each having relative benefits and weaknesses. Choice for optimal treatment is made on a... (Review)
Review
Treatment of recurrent Dupuytren disease is challenging. Multiple options exist, each having relative benefits and weaknesses. Choice for optimal treatment is made on a case-by-case basis, with shared decision making with the patient. Percutaneous and enzymatic techniques are best reserved for patients with well-defined recurrent disease and offer the benefit of quicker recovery with minimal or no scarring. Surgical treatments have higher risks of neurovascular injury and scarring, but lower recurrence rates. Staged continuous passive elongation followed by dermofasciectomy may lower neurovascular injury and improve outcomes. Salvage procedures may be necessary in patients with poor tissue beds and neurovascular compromise.
Topics: Aponeurosis; Clostridium histolyticum; Dupuytren Contracture; External Fixators; Fasciotomy; Humans; Injections, Intralesional; Microbial Collagenase; Needles; Orthopedic Procedures; Postoperative Care; Preoperative Care; Recurrence; Salvage Therapy; Secondary Prevention; Surgical Flaps
PubMed: 30012300
DOI: 10.1016/j.hcl.2018.03.009 -
Journal of the Belgian Society of... Apr 2021Subgaleal lipoma is a benign tumor of adipose tissue. It should be suspected when a semi-spherical avascular mass with well-defined margins, iso- or hyperechoic in most...
UNLABELLED
Subgaleal lipoma is a benign tumor of adipose tissue. It should be suspected when a semi-spherical avascular mass with well-defined margins, iso- or hyperechoic in most cases, with thin internal echogenic lines parallel to the long axis of the tumor, is observed between the galea aponeurosis and periosteum of the cranial bone. We report a series of cases of three patients who underwent surgical lesion excision and whose histopathological examination findings confirmed the diagnosis of lipoma.
MAIN TEACHING POINT
The presence of long continuous echogenic lines within a lens-shaped soft tissue mass located beneath the galea aponeurosis may suggest the diagnosis of subgaleal lipoma.
PubMed: 33977221
DOI: 10.5334/jbsr.2372 -
European Journal of Sport Science Sep 2018There is an abundance of evidence that suggests elastic tendons can enhance both animal and human muscle performance. However, in many terrestrial animals, including... (Review)
Review
There is an abundance of evidence that suggests elastic tendons can enhance both animal and human muscle performance. However, in many terrestrial animals, including humans, a large proportion of the elastic tissue within the muscle-tendon unit is located within the muscle. This continuous elastic sheet, which provides muscle fibre attachment, is known as the aponeurosis. The aponeurosis has a much more complicated shape than the free tendon and it undergoes a more complicated loading regime during contraction, due to its relationship with the bulging muscle fibres, which remain isovolumetric during force production. Muscle contraction may dynamically modulate the stiffness of the aponeurosis at the same active versus passive force, by increasing the intramuscular pressure and transverse forces within the muscle, which may stretch the aponeurosis in width and subsequently reduce its longitudinal strain. Some evidence also suggests that the aponeurosis mechanical properties may be affected by muscle length, which appears to reduce the fascicle strains for a given muscle force at longer muscle lengths. This narrative review outlines the animal and human studies that have investigated aponeurosis behaviour during contraction and discusses how an elastic sheet with a variable stiffness under activation might be beneficial for muscle performance. While it is clear that our understanding of the role of aponeurosis is lacking, it is hoped that further work will attempt to determine how this tissue contributes to power amplification and elastic energy savings during locomotion and potentially uncover how aponeurosis behaviour contributes to injury risk.
Topics: Animals; Aponeurosis; Humans; Locomotion; Muscle Contraction; Muscle, Skeletal; Tendons
PubMed: 29806988
DOI: 10.1080/17461391.2018.1472299 -
Polski Przeglad Chirurgiczny Oct 2022Dupuytrens disease is a common fibrotic disorder of the palmar aponeurosis characterized by the formation of nodules and cords, as well as development of progressive... (Review)
Review
Dupuytrens disease is a common fibrotic disorder of the palmar aponeurosis characterized by the formation of nodules and cords, as well as development of progressive flexion deformities in the digits, leading to functional impairment. Surgical excision of the affected aponeurosis remains the most common treatment. Quite a few new information appeared about epidemiology, pathogenesis and particularly treatment of the disorder. The objective of this study is an updated review of scientific data in this topic. Results of epidemiologic studies showed that Dupuytrens disease is not so uncommon in Asian and African population as it was earlier believed. An important role of genetic factors on development of the disease in a proportion of patients was demonstrated, however, it did not translate neither to the treatment nor to the prognosis. The most changes concerned the management of Dupuytrens disease. A positive effect of steroids injections into the nodules and cords for inhibition of the disease in early stages was shown. In the advanced stages, a standard technique of partial fasciectomy was partly replaced by mini-invasive methods such as needle fasciotomy and collagenase Clostirdium hystolyticum injections. Unexpected withdrawal of collagenase from the market in 2020 resulted in considerable limitation of the availability of this treatment. It seems that updated knowledge on Dupuytrens disease may be interested and useful for surgeons involved in management of the disorder.
Topics: Humans; Dupuytren Contracture; Collagenases; Fasciotomy
PubMed: 36808068
DOI: 10.5604/01.3001.0016.0058