The Achilles tendon is the strongest and thickest tendon in the human body. It is also the commonest tendon to rupture. It begins near the middle of the calf and is the conjoint tendon of the gastrocnemius and soleus muscles. The relative contribution of the two muscles to the tendon varies. Spiralisation of the fibres of the tendon produces an area of concentrated stress and confers a mechanical advantage. The calcaneal insertion is specialised and designed to aid the dissipation of stress from the tendon to the calcaneum. The insertion is crescent shaped and has significant medial and lateral projections. The blood supply of the tendon is from the musculotendinous junction, vessels in surrounding connective tissue and the osteotendinous junction. The vascular territories can be classified simply in three, with the midsection supplied by the peroneal artery, and the proximal and distal sections supplied by the posterior tibial artery. This leaves a relatively hypovascular area in the mid-portion of the tendon where most problems occur. The Achilles tendon derives its innervation from the sural nerve with a smaller supply from the tibial nerve. Tenocytes produce type I collagen and form 90% of the cellular component of the normal tendon. Evidence suggests ruptured or pathological tendon produce more type III collagen, which may affect the tensile strength of the tendon. Direct measurements of forces reveal loading in the Achilles tendon as high as 9 KN during running, which is up to 12.5 times body weight.
In sonoelastography, the recognition of normal tendon structure will be useful in assessing pathologies of the Achilles tendon. Additionally, in patients with excellent American Orthopedic Foot and Ankle Society (AOFAS) scores and surgically repaired complete ruptures, a hard and heterogeneous pattern of tendon structure may be a natural consequence of tendon healing.
Pelvic floor dysfunction (PFD), although seems to be simple, is a complex process that develops secondary to multifactorial factors. The incidence of PFD is increasing with increasing life expectancy. PFD is a term that refers to a broad range of clinical scenarios, including lower urinary tract excretory and defecation disorders, such as urinary and anal incontinence, overactive bladder, and pelvic organ prolapse, as well as sexual disorders. It is a financial burden on the health care system and disrupts women's quality of life. Strategies applied to decrease PFD are focused on the course of pregnancy, mode and management of delivery, and pelvic exercise methods. Many studies in the literature define traumatic birth, usage of forceps, length of the second stage of delivery, and sphincter damage as modifiable risk factors for PFD. Maternal age, fetal position, and fetal head circumference are nonmodifiable risk factors. Although numerous studies show that vaginal delivery affects pelvic floor structures and their functions in a negative way, there is not enough scientific evidence to recommend elective cesarean delivery in order to prevent development of PFD. PFD is a heterogeneous pathological condition, and the effects of pregnancy, vaginal delivery, cesarean delivery, and possible risk factors of PFD may be different from each other. Observational studies have identified certain obstetrical exposures as risk factors for pelvic floor disorders. These factors often coexist; therefore, the isolated effects of these variables on the pelvic floor are difficult to study. The routine use of episiotomy for many years in order to prevent PFD is not recommended anymore; episiotomy should be used in selected cases, and the mediolateral procedures should be used if needed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.