Compartments of the crural fascia: clinically relevant ultrasound, anatomical and histological findings.

PURPOSE: Compartment syndrome is a surgical emergency that can occur in any part of the body and can cause cell necrosis when maintained over time. The resulting defects can affect the nerves, muscle cells, bone tissue, and other connective tissues inside the compartment, and fasciotomy has to be performed. The anatomical and histological characteristics of the leg make acute, chronic, and exertional compartment syndrome more likely in this limb. For these reasons, knowledge of the ultrasound, anatomical, and histological features of the crural fascia can help in the treatment of leg compartment syndrome. METHODS: Twenty-one cryopreserved lower limbs from adult cadavers and from one 29-week-old fetus were obtained from the dissection room. They were examined by ultrasound and a subsequent anatomical dissection and microscopy to study the crural fascia and its relationship with the different muscles. Anthropometric measurements were taken of the distances from the head of the fibula and lateral malleolus to the origin of the tibialis anterior muscle in the crural fascia, the exit of the superficial fibular nerve, and the fascia covering the deep posterior muscles of the leg. RESULTS: The crural fascia has very important clinical relationships, which can be identified by ultrasound, as the origin of the tibialis anterior muscle at 16.25 cm from the head of the fibula and the exit of the superficial fibular nerve that crosses this fascia at 21.25 cm from the head of the fibula. Furthermore, the presence of a septum that fixes the deep posterior muscles of the leg and the vessels and nerve can be seen by ultrasound and can explain the possible development of a posterior compartmental syndrome of the leg. Awareness of these features will help to keep these structures safe during the surgical treatment of compartment syndrome. CONCLUSION: The ultrasound study allows identification of anatomical structures in the leg and, thus, avoids damage to them during surgery for compartmental syndromes.

Anatomical causes of compression of the sciatic nerve in the pelvis. Piriform syndrome. / Causas anatómicas de compresión del nervio ciático en la pelvis. Síndrome piriforme.

OBJECTIVE: The piriformis syndrome is one of the etiologies of pelvic pain due to the sciatic nerve's entrapment by the piriformis muscle. Nowadays this syndrome might be difficult to be diagnosed. The aim of this study is to know the prevalence of anatomic variations in our population that may contribute to the appearance of piriformis syndrome. Furthermore, anthropometric measurements of the piriformis muscle and the sciatic nerve procedures are studied for a possible application in the gluteal region. MATERIAL AND METHOD: The study was carried out in 59 pelvis of 32 cryopreserved bodies. The anatomical variations of piriformis and sciatic nerve founded were described following the Beaton and Anson's classification. Anthropometric measurements of both structures with reference to the greater trochanter of the femur were performed. RESULTS: The sciatic nerve and the piriformis had an anatomical variation in a 28.13%. The most frequent variation found was tipus II (21.64%) and tipus III (6.49%).Insertion most frequently observed was an independent piriformis tendon inserted into the trochanteric fossa with 53.85%. CONCLUSION: The anatomic variations' incidence in the population studied indicates that those have to be evaluated as a differential diagnosis of gluteal region pain due to the symptoms and signs resemblance with the vertebral disc pathology involving nerve root injury. In addition, anatomical knowledge of this region can be useful for the interpretation of imaging techniques, especially when ultrasound-guided injections are performed.