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Insights Into Imaging Oct 2023Peripheral nerves of the lower limb may become entrapped at various points during their anatomical course. While clinical assessment and nerve conduction studies are the... (Review)
Review
Peripheral nerves of the lower limb may become entrapped at various points during their anatomical course. While clinical assessment and nerve conduction studies are the mainstay of diagnosis, there are multiple imaging options, specifically ultrasound and magnetic resonance imaging (MRI), which offer important information about the potential cause and location of nerve entrapment that can help guide management. This article overviews the anatomical course of various lower limb nerves, including the sciatic nerve, tibial nerve, medial plantar nerve, lateral plantar nerve, digital nerves, common peroneal nerve, deep peroneal nerve, superficial peroneal nerve, sural nerve, obturator nerve, lateral femoral cutaneous nerve and femoral nerve. The common locations and causes of entrapments for each of the nerves are explained. Common ultrasound and MRI findings of nerve entrapments, direct and indirect, are described, and various examples of the more commonly observed cases of lower limb nerve entrapments are provided.Critical relevance statement This article describes the common sites of lower limb nerve entrapments and their imaging features. It equips radiologists with the knowledge needed to approach the assessment of entrapment neuropathies, which are a critically important cause of pain and functional impairment.Key points• Ultrasound and MRI are commonly used to investigate nerve entrapment syndromes.• Ultrasound findings include nerve hypo-echogenicity, calibre changes and the sonographic Tinel's sign.• MRI findings include increased nerve T2 signal, muscle atrophy and denervation oedema.• Imaging can reveal causative lesions, including scarring, masses and anatomical variants.
PubMed: 37782348
DOI: 10.1186/s13244-023-01514-6 -
Journal of Nippon Medical School =... 2024Tarsal tunnel syndrome (TTS) is a common entrapment neuropathy that is sometimes elicited by ganglia in the tarsal tunnel.
BACKGROUND
Tarsal tunnel syndrome (TTS) is a common entrapment neuropathy that is sometimes elicited by ganglia in the tarsal tunnel.
METHODS
Between August 2020 and July 2022, we operated on 117 sides with TTS. This retrospective study examined data from 8 consecutive patients (8 sides: 5 men, 3 women; average age 67.8 years) with an extraneural ganglion in the tarsal tunnel. We investigated the clinical characteristics and surgical outcomes for these patients.
RESULTS
The mass was palpable through the skin in 1 patient, detected intraoperatively in 1 patient, and visualized on MRI scanning in the other 6 patients. Symptoms involved the medial plantar nerve area (n = 5), lateral plantar nerve area (n = 1), and medial and lateral plantar nerve areas (n = 2). The interval between symptom onset and surgery ranged from 4 to 168 months. Adhesion between large (≥20 mm) ganglia and surrounding tissue and nerves was observed intraoperatively in 4 patients. Of the 8 patients, 7 underwent total ganglion resection. There were no surgery-related complications. On their last postoperative visit, 3 patients with a duration of symptoms not exceeding 10 months reported favorable outcomes.
CONCLUSIONS
Because ganglia eliciting TTS are often undetectable by skin palpation, imaging studies may be necessary. Early surgical intervention appears to yield favorable outcomes.
Topics: Male; Humans; Female; Aged; Tarsal Tunnel Syndrome; Retrospective Studies; Magnetic Resonance Imaging; Skin
PubMed: 38462440
DOI: 10.1272/jnms.JNMS.2024_91-203 -
Journal of Ultrasonography Sep 2023Plantar intrinsic muscles play a pivotal role in posture control and gait dynamics. They help maintain the longitudinal and transverse arches of the foot, and they...
Plantar intrinsic muscles play a pivotal role in posture control and gait dynamics. They help maintain the longitudinal and transverse arches of the foot, and they regulate the degree and velocity of arch deformation during walking or running. Consequently, pathologies affecting the plantar intrinsic muscles (for instance, acquired and inherited neuropathies) lead to foot deformity, gait disorders, and painful syndromes. Intrinsic muscle malfunctioning is also associated with multifactorial overuse or degenerative conditions such as pes planus, hallux valgus, and plantar fasciitis. As the clinical examination of each intrinsic muscle is challenging, ultrasound is gaining a growing interest as an imaging tool to investigate the trophism of these muscular structures and the pattern of their alterations, and potentially to follow up on the effects of dedicated rehabilitation protocols. The ten plantar intrinsic muscles can be dived into three groups (medial, central and lateral) and four layers. Here, we propose a regional and landmark-based approach to the complex sonoanatomy of the plantar intrinsic muscles in order to facilitate the correct identification of each muscle from the superficial to the deepest layer. We also summarize the pathological ultrasound findings that can be encountered when scanning the plantar muscles, pointing out the patterns of alterations specific to certain conditions, such as plantar nerves mononeuropathies.
PubMed: 37732108
DOI: 10.15557/jou.2023.0024 -
American Family Physician Oct 2011Heel pain is a common presenting symptom in ambulatory clinics. There are many causes, but a mechanical etiology is most common. Location of pain can be a guide to the... (Review)
Review
Heel pain is a common presenting symptom in ambulatory clinics. There are many causes, but a mechanical etiology is most common. Location of pain can be a guide to the proper diagnosis. The most common diagnosis is plantar fasciitis, a condition that leads to medial plantar heel pain, especially with the first weight-bearing steps in the morning and after long periods of rest. Other causes of plantar heel pain include calcaneal stress fracture (progressively worsening pain following an increase in activity level or change to a harder walking surface), nerve entrapment (pain accompanied by burning, tingling, or numbness), heel pad syndrome (deep, bruise-like pain in the middle of the heel), neuromas, and plantar warts. Achilles tendinopathy is a common condition that causes posterior heel pain. Other tendinopathies demonstrate pain localized to the insertion site of the affected tendon. Posterior heel pain can also be attributed to a Haglund deformity, a prominence of the calcaneus that may cause bursa inflammation between the calcaneus and Achilles tendon, or to Sever disease, a calcaneal apophysitis in children. Medial midfoot heel pain, particularly with continued weight bearing, may be due to tarsal tunnel syndrome, which is caused by compression of the posterior tibial nerve as it courses through the flexor retinaculum, medial calcaneus, posterior talus, and medial malleolus. Sinus tarsi syndrome occurs in the space between the calcaneus, talus, and talocalcaneonavicular and subtalar joints. The syndrome manifests as lateral midfoot heel pain. Differentiating among causes of heel pain can be accomplished through a patient history and physical examination, with appropriate imaging studies, if indicated.
Topics: Achilles Tendon; Calcaneus; Diagnosis, Differential; Fasciitis, Plantar; Foot Diseases; Fractures, Stress; Heel; Heel Spur; Humans; Pain; Tarsal Tunnel Syndrome; Tendinopathy
PubMed: 22010770
DOI: No ID Found