The Intraseptal Course of the Superficial Peroneal Nerve: An Anatomic Study

Sciatic and tibial neuropathies

The sciatic nerve is the body's largest peripheral nerve. Along with their two terminal divisions (tibial and fibular), their anatomic location makes them particularly vulnerable to trauma and iatrogenic injuries. A thorough understanding of the functional anatomy is required to adequately localize lesions in this lengthy neural pathway. Proximal disorders of the nerve can be challenging to precisely localize among a range of possibilities including lumbosacral pathology, radiculopathy, or piriformis syndrome. A correct diagnosis is based upon a thorough history and physical examination, which will then appropriately direct adjunctive investigations such as imaging and electrodiagnostic testing. Disorders of the sciatic nerve and its terminal branches are disabling for patients, and expert assessment by rehabilitation professionals is important in limiting their impact. Applying techniques established in the upper extremity, surgical reconstruction of lower extremity nerve dysfunction is rapidly improving and evolving. These new techniques, such as nerve transfers, require electrodiagnostic assessment of both the injured nerve(s) as well as healthy, potential donor nerves as part of a complete neurophysiological examination.

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.

A Traumatic Neuroma Formation Following Fasciotomy for the Treatment of Tibialis Anterior Muscle Herniation: A Case Report

Muscle herniation of the lower extremity, such as tibialis anterior muscle herniation (TAMH), is not a rare cause of leg pain in athletes. However, a few studies have reported surgical treatment for TAMH, and the optimal surgical procedure remains controversial. Fasciotomy was reported to be effective for patients with TAMH. However, this procedure would be associated with a risk of intraoperative injury to the superficial peroneal nerve (SPN), although no previous literature has reported this complication. This case report aimed to report a case of bilateral TAMHs in which a traumatic neuroma of the SPN developed after fasciotomy. A 16-year-old baseball player presented with painful swelling lesions of the bilateral lower extremities (1 lesion on the right, 3 lesions on the left) after sports activities. An ultrasonographic evaluation showed swelling lesions of the anterolateral parts of the bilateral lower extremities in the standing position after dashing, while these lesions were not detected in the supine position. A fasciotomy of the crural fascia was performed after conservative treatment failed. Several days after surgery, the patient presented with weakened touch sensation over the dorsal area of the left foot. At the three-month follow-up examination, a swelling lesion with hard elasticity was identified. The palpation of this lesion caused a radiating sensation in the area supplied by the SPN. He was able to return to playing baseball six months after surgery. The patient was asymptomatic without palpation of the traumatic neuroma of the SPN at the latest follow-up examination. In conclusion, the present case report suggests that orthopedic surgeons need to consider the risk of iatrogenic injury to the SPN during fasciotomy for the treatment of TAMHs. However, there may be a risk of injuring the SPN because of the many variants of the course of the SPN within the compartment of the lower extremities.

Ultrasound-guided hydrodissection of the superficial peroneal nerve for chronic neuropathic pain: a war veteran's story

Aim: This case report presents the application of ultrasound-guided hydrodissection of the superficial peroneal nerve to treat chronic refractory neuropathic pain, rated by the patient with an average intensity of 6/10 on the numerical rating scale. Materials & methods: Under ultrasound guidance, the nerve was identified compressed by a herniation of the peroneus brevis. An in-plane hydrodissection was performed using a solution of 10 ml of ropivacaine and methylprednisolone until the epineurium was entirely separated from the surrounding tissue. Results: At the 2-month follow-up, the patient reported a decrease of pain, which he rated a 2/10 on the numerical rating scale. At this point, night-time episodes of moderate pain persisted. The procedure was repeated and at the 6-month follow-up, the patient remained pain free. Conclusion: This case report suggests that consecutive ultrasound-guided hydrodissection techniques might be a valuable option in the treatment of superficial peroneal nerve entrapment neuropathy.