Sonographic Evaluation of Superficial Peroneal Nerve Abnormalities.

OBJECTIVE: The objective of this study was to review the anatomy of the superficial peroneal nerve (SPN) and describe the sonographic appearances of various abnormalities affecting it. We performed a retrospective chart review of ultrasound (US) examinations of the SPN performed from 2014 to 2016. CONCLUSION: SPN abnormalities are well shown on US. Of 181 patients examined with US, the most commonly detected abnormality was scar encasement and neuroma or laceration.

Ultrasound to depict anatomical abnormality: an example of potential alliance of rehabilitation professionals.

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The developmental and genetic basis of 'clubfoot' in the peroneal muscular atrophy mutant mouse.

Genetic factors underlying the human limb abnormality congenital talipes equinovarus ('clubfoot') remain incompletely understood. The spontaneous autosomal recessive mouse 'peroneal muscular atrophy' mutant (PMA) is a faithful morphological model of human clubfoot. In PMA mice, the dorsal (peroneal) branches of the sciatic nerves are absent. In this study, the primary developmental defect was identified as a reduced growth of sciatic nerve lateral motor column (LMC) neurons leading to failure to project to dorsal (peroneal) lower limb muscle blocks. The pma mutation was mapped and a candidate gene encoding LIM-domain kinase 1 (Limk1) identified, which is upregulated in mutant lateral LMC motor neurons. Genetic and molecular analyses showed that the mutation acts in the EphA4-Limk1-Cfl1/cofilin-actin pathway to modulate growth cone extension/collapse. In the chicken, both experimental upregulation of Limk1 by electroporation and pharmacological inhibition of actin turnover led to defects in hindlimb spinal motor neuron growth and pathfinding, and mimicked the clubfoot phenotype. The data support a neuromuscular aetiology for clubfoot and provide a mechanistic framework to understand clubfoot in humans.

Prevalence of the accessory deep peroneal nerve: A cadaveric study and meta-analysis.

OBJECTIVES: The accessory deep peroneal nerve (ADPN) is a common anatomical variant arising from the superficial peroneal nerve (SPN) and, when present, is often responsible for partial or complete innervation of the extensor digitorum brevis muscle (EDBM). The nerve lies posterior to the peroneus brevis muscle, traveling posterior to the lateral malleolus to terminate in the ankle by giving off sensory branches to the ankle and joints. Although the EDBM is usually supplied by the deep peroneal nerve (DPN), in the presence of an ADPN, electrodiagnostic procedures may be complicated. Due to the lack of detailed anatomical knowledge on the topography of the ADPN, its presence posterior to the lateral malleolus can be iatrogenically injured during surgical procedures on the ankle using a lateral approach. Therefore, this meta-analysis aimed to provide a comprehensive, evidence-based assessment of the anatomical characteristics of the ADPN, supplemented with data from our own cadaveric dissection. PATIENTS AND METHODS: A comprehensive search of all major electronic databases, including Pubmed, Embase, Scopus, Web of Science, ScienceDirect, SciELO, and BIOSIS was performed. All articles with data on prevalence, symmetry and innervation of the EDBM by the ADPN were included. The anatomical data was then extracted and pooled into a meta-analysis using MetaXL 2.0. In addition, we dissected 21 cadavers (n=42 lower limbs) bilaterally to find the ADPN. RESULTS: A total of 19 studies (n=6070 lower limbs) were included in the meta-analysis. The pooled prevalence of the ADPN was 18.8% (95%CI:14.2-24.0) with a 39.3% prevalence rate for cadaveric studies. The ADPN was present more commonly unilaterally (67.0%) and when it was present, provided branches to the EDBM in 79.5% of cases. In our cadaveric study, the ADPN was identified in 5 of the 42 lower limbs dissected (11.9%); on the right side in 3 lower limbs and on the left side in 2 lower limbs. CONCLUSIONS: The ADPN is a clinically important nerve and has been inculpated in unexplained cases of chronic ankle pain and EDBM atrophy. The variability in detection of the ADPN using electrophysiological techniques can lead to misdiagnoses of peroneal nerve lesions and increase the risk for iatrogenic injury to the ADPN, especially in laterally approaching ankle procedures and sural nerve biopsies.

Efeitos da irradiação com laser de baixa potência nas glândulas salivares submandibulares de ratas diabéticas induzidas por estreptozotocina / Low-power laser irradiation effects in submandibular glands of streptozotocin-induced diabetic rats

O diabetes mellitus (DM) pode levar à disfunção das glândulas salivares. A ativação do receptor de produtos finais de glicosilação avançada e de seus ligantes tem sido reportado em várias doenças crônicas, entre estas, a diabetes e suas complicações. Este estudo analisou a expressão do RAGE, proteína do grupo de alta mobilidade B1 (HMGB1) e de produtos de glicosilação avançada (AGE), bem como os efeitos da irradiação com laser de baixa potência (ILBP) em glândulas salivares submandibulares (GSMs) de ratas diabéticas. Ratas Wistar com 12 semanas de vida foram divididas em 3 grupos: controle (C), diabético (D) e diabético com laser (DL). A indução de DM nos grupos D e DL foi realizada com injeção intraperitoneal de estreptozotocina 60 mg/kg de peso corporal, no 1° dia experimental. No 29°dia, os animais do grupo DL receberam a ILBP (660 nm, 70 mW, 20 J/cm² e 0,56 J por ponto), aplicado no total de quarenta pontos cobrindo a área correspondente as GSMs, e os seus efeitos foram avaliados 24 h após a irradiação (eutanásia). As análises de parâmetros metabólicos, histológicos e de marcadores de inflamação, apoptose e proliferação foram realizadas. Nossos achados mostram que a ILBP diminuiu a glicemia das ratas diabéticas irradiadas, melhorando a resistência à insulina (HOMA-IR), sensibilidade à insulina (HOMA-IS) e função de células beta (HOMA-?). Em GSM, o DM parece aumentar a expressão do eixo HMGB1/AGE/RAGE, possivelmente associado à ativação do fator de transcrição nuclear kappa B (NF?B). A ILBP reduziu os marcadores de inflamação, HMGB1 e TNF-? em GSM de ratas diabéticas, e parece regular a expressão de proteínas relacionadas à proliferação e à apoptose, pela via do AMP cíclico, parcialmente mediado por proteína kinase regulada por sinais extracelulares. No entanto, mais estudos são necessários para melhor entender os efeitos do laser neste tecido.

Diabetes (DM) can lead to dysfunction of the secretory capacity in salivary glands. Since the activation of the receptor for advanced glycation end-products (RAGE) and its ligands has been suggested to participate in chronic disorders, such as diabetes and its complications. This study analyzed the expression of RAGE, high mobility group box protein B1 (HMGB1) and advanced glycation end-products (AGEs) were evaluated, as well as the effects of low-power laser irradiation (ILBP), in diabetic submandibular glands (GSM). Wistar rats 12 weeks-old were divided in three groups: control (C), diabetic (D) and diabetic with laser (DL). The D and DL rats were intraperitoneally injected with streptozotocin 60 mg/kg, in the 1st experimental day. On the 29° day, the DL rats received the ILBP (660 nm, 70 mW, 20 J/cm² e 0,56J per point), with a total of forty points covering the GSMs area, its effects were evaluated 24h after irradiation (euthanasia). Metabolic parameters, histology and the inflammatory, apoptosis and proliferation markers were evaluated. Our findings show that ILBP reduced the blood glucose levels of the irradiated diabetic rats, improving their insulin resistance (HOMA-IR), insulin sensitivity (HOMA-IS) e beta cell function (HOMA-?). In GSM, DM seems to upregulate the expression of HMGB1/AGE/RAGE axis, possibly associated with the activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF?B). The ILBP reduced the inflammatory markers HMGB1 and TNF-? in diabetic GSM, and seems to regulate the expression of proteins related to proliferation and apoptosis, by cyclic AMP pathway, partially mediated by extracellular signal-regulated kinase. However, more studies are necessary to better understand the laser effects on this tissue.

Anatomical variations of the formation and course of the sural nerve: A systematic review and meta-analysis.

INTRODUCTION: The sural nerve (SN) is a sensory nerve in the lower extremity which branches to supply the skin on the distal posterolateral third of the lower limb. Typically, the medial sural cutaneous nerve (MSCN) and the peroneal communicating nerve (PCN) unite to form the SN. Other variations in the formation, course, and morphometry of the SN have also been described in the literature. OBJECTIVE: To study anatomical variations in the formation and course of the SN and establish a new classification system for formation patterns of the SN. METHODS: A systematic search of all major databases identified articles that studied the prevalence of variations in the formation of the SN. No date or language restrictions were set. Anatomical data was extracted according to our new classification system where the SN is formed by: union of the MSCN and the PCN (Type 1); union of the MSCN and the Lateral Sural Cutaneous Nerve (LSCN) (Type 2); continuation of the MSCN with absent PCN (Type 3); the PCN alone (Type 4); the LSCN (Type 5); or the Sciatic Nerve (SCN) directly (Type 6). Pooled prevalence rates were calculated using MetaXL 2.0. RESULTS: A total of 39 studies (n=3974 limbs) were included in the meta-analysis. The most common patterns were Type 1, Type 3, and Type 2 with a pooled prevalence of 51.5% (95% CI: 0.293-0.591), 31.2% (95% CI: 0.143-0.410), and 13.8% (95% CI: 0.035-0.234), respectively. The rest of the patterns were rare, with pooled prevalence of Types 4, 5, and 6 calculated to be 1.8% (95% CI: 0-0.063), 1.1% (95% CI: 0-0.050), and 0.7% (95% CI: 0-0.041), respectively. In 83.7% (95% CI: 0.765-0.899) of limbs, the site of union was in the lower half of the lower extremity. The pooled mean length of the SN from the formation to the lateral malleolus was 14.78 (±5.76) cm, while the mean diameter of the SN was 0.28 (±0.03) cm. CONCLUSIONS: Anatomical variations in the formation and course of the SN are common in the population. Clinicians, especially surgeons, should be aware of these variations to avoid iatrogenic injury to the nerve during operative procedures.

[Rare anatomical variation of absence of the sciatic nerve: completely substituted by the tibial and common fibular nerve]. / Variação anatómica rara de ausência do nervo ciático: completamente substituído pelos nervos tibial e fibular comum.

INTRODUCTION: There are several reports of sciatic nerve anatomical variations. Some are associated with clinical entities, such as piriformis syndrome. We aim to report a rare anatomical variation of this nerve. CASES REPORT: Two leucodermic, 74 and 78-year-old male subjects, deceased of natural causes, without lower limb relevant medical history. In both subjects, the right sciatic nerve was absent, with an independent origin and course of the tibial and common fibular nerves. The contralateral sciatic nerve had the common anatomical presentation. DISCUSSION: After the analysis of the available data indexed in Medline, we conclude that we are reporting two cases of a rare anatomical variation (the absence of sciatic nerve, with an independent origin and course of the tibial and common fibular nerve). This anatomical variation may have clinical importance, as it may be, for example, a risk factor to unsuccessful sciatic nerve popliteal blocks and to the pyriformis syndrome.

Introdução: Existem várias publicações referindo variantes anatómicas do nervo ciático, algumas associadas a síndromes clínicos (como sendo a síndrome do músculo piriforme). Neste contexto, pretendemos apresentar uma variante anatómica rara do nervo ciático.Casos clínicos: Dois cadáveres leucodérmicos, masculinos, com 74 e 78 anos, falecidos de morte natural, sem patologia do membro inferior. Em ambos os casos, observou-se ausência do nervo ciático direito, tendo os nervos tibial e fibular comum origem e trajecto independentes, desde a sua origem nas raízes lombo-sagradas até à região poplítea. O nervo ciático contralateral apresentava a anatomia habitual.Discussão: Analisando a literatura, na Medline, realçamos que apresentamos dois casos raros de ausência do nervo ciático, com origem e trajecto independentes dos nervos tibial e fibular comum. Esta variante poderá ter implicações clínicas, nomeadamente ser um factor de risco para o insucesso de bloqueios anestésicos poplíteos e para a síndrome do músculo piriforme.

The accessory deep peroneal nerve and anterior tarsal tunnel syndrome: case report.

The accessory deep peroneal (ADPN) nerve has been regarded as an anomalous nerve derived from the superficial peroneal nerve or its branch and supplies motor innervations for extensor digitorum brevis (EDB) and sensory innervations for the lateral part of the ankle and foot regions. The EDB is usually innervated exclusively by the deep peroneal nerve, a major branch of the the common peroneal nerve, however, in as many as 28% of patients (with same male/female frequency), one or both of the EDB muscles are (partially or exclusively) innervated by the ADPN nerve. This anomaly appears to be inherited in autosomal dominant fashion with incomplete gene penetrance. ADPN existence is of great clinical and surgical importance, and the aim of this study is to describe a very rare case of coexistence ADPN and anterior tarsal tunnel syndrome.

Unique distribution by the peroneal nerves: a case report.

PURPOSE: Among the branches of common peroneal nerve, the superficial peroneal provides cutaneous innervation to major part of the dorsum of the foot and deep peroneal nerve supplies the skin over the first interdigital cleft region. METHODS: The present rare case was observed during routine dissection of leg for undergraduate students, in a 52-year-old male, formalin fixed cadaver. RESULTS: The superficial peroneal nerve provided solely motor branches to peroneus longus and brevis, whereas cutaneous branches were provided by deep peroneal nerve. In the lower one-third of the leg deep peroneal nerve divided into medial and lateral branches. The medial branch supplied tibialis anterior and the lateral branch supplied skin of medial three and half toes. Moreover, the sural nerve supplied the skin of lateral one and a half toes. CONCLUSION: Awareness of this type of variations in the course of nerves helps to alert the surgeons when there are complaints of atypical or unique pain in that particular region.

Ultrasound diagnosis of peroneal nerve variant in a child with compressive mononeuropathy.

We report on a 6-year-old child presenting with subacute foot drop. Neurophysiologic and radiologic studies revealed a peroneal nerve compression secondary to fibular exostosis. Before undergoing surgical removal of the exostosis, the patient underwent further neurophysiologic and ultrasonographic evaluation that showed the presence of an accessory peroneal nerve branch that caused gastrocnemius involvement. Findings at surgery confirmed the supposed anatomical variant. Both nerve components were carefully preserved during the operative procedure. The association of ultrasonographic and neurophysiologic studies was crucial in identifying the etiopathologic mechanism and anatomical picture and provided clinicians and surgeons with important information in planning the procedure.

The drop toe sign: an indicator of neurologic impairment in congenital clubfoot.

UNLABELLED: Nine patients presenting during infancy were identified with clubfeet and absent anterior and lateral compartment functions. We considered these to be neurogenic clubfeet. All patients had the drop toe sign: resting posture of the toes in plantarflexion and absent active dorsiflexion movement after plantar stimulation of the foot. Two patients (three feet) underwent exploration of the peroneal nerve, which revealed anatomic abnormalities. Six patients required more casts than typical for initial correction of deformity; all but two had Achilles tenotomy. Four relapsed despite full-time bracing and eventually needed intraarticular surgery to achieve a plantigrade foot. Idiopathic absent peroneal nerve function is not a well-described entity in the clubfoot literature. All babies with clubfoot should be examined for the drop toe sign. When noted, the feet will likely be more difficult to correct initially, may need early Achilles tendon lengthening, will likely need permanent bracing, are likely to relapse and need intraarticular surgery, and may need multiple surgeries to remain plantigrade throughout growth. LEVEL OF EVIDENCE: Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Lesion of the common peroneal nerve during arthroscopy.

Arthroscopic knee surgery has been well accepted worldwide and has become an important part of orthopaedic surgery. The use of arthroscopy has reduced the duration of hospitalization, overall costs, and time required for the patient to return to sports activities or work. However, because of the closed nature of the procedure and proximity of neurovascular structures to instruments, substantial risk of injuries exists. Significant anatomic variability in the nerve course has not been reported in previous literature as a cause of a knee arthroscopy complication. We present a case of complete transection of an unusually located common peroneal nerve during a knee arthroscopy for lateral meniscal repair in a 22-year-old football player.

MR imaging of popliteal pterygium syndrome in pediatric patients.

OBJECTIVE: Our purpose was to describe the use of MR imaging in the evaluation of the positions of the popliteal artery and peroneal nerve in children with popliteal pterygium syndrome for preoperative planning and to describe the typical appearance of popliteal pterygium on MR imaging. CONCLUSION: By depicting the popliteal artery and peroneal nerve either in normal positions or abnormally located immediately adjacent to the pterygium, MR imaging provides useful information for preoperative planning in children with popliteal pterygium syndrome. The MR appearance of a popliteal pterygium is that of a band of abnormal tissue extending from the ischium to the os calcis that has signal characteristics of fibrous tissue often attached to a belly of anomalous muscle.

Innervation anomalies in upper and lower extremities (an electrophysiological study).

A hundred and eight subjects were studied for the frequent occurrence innervation anomalies in upper and lower extremities. Martin-Gruber Anomalies (MGA) were found in 19 (17.5%) subjects. The anomaly was bilateral in 14 subjects (73.6%). No case of motor ulnar to median nerve anastomosis in the forearm could be found. The 73.1, 20.8 and 14.3% incidences of the neural communication between the ulnar and median nerves in the hand were detected, in the Abductor Pollicis Brevis (APB), in the First Dorsal Interosseus (FDI) and in the Abductor Digiti Minimi (ADM) muscles, respectively. The existence of an accessory deep peroneal nerve was found in 23 (21.3%) subjects and 40 (18.5%) of legs. The anomaly was bilateral in 17 subjects (74%). We observed both MGA and accessory deep peroneal nerve in 9 cases.

The consistent presence of the human accessory deep peroneal nerve.

Twenty-four human legs were dissected macroscopically to study the morphological details of the accessory deep peroneal nerve. This nerve arose from the superficial peroneal nerve and descended in the lateral compartment of the leg, deep to peroneus longus along the posterior border of peroneus brevis. Approaching the ankle joint, this nerve passed through the peroneal tunnels to wind around the lateral malleolus; it then crossed beneath the peroneus brevis tendon anteriorly to reach the dorsum of the foot. The accessory deep peroneal nerve was found in every case examined and constantly gave off muscular branches to peroneus brevis and sensory branches to the ankle region. In addition, this nerve occasionally had muscular branches to peroneus longus and extensor digitorum brevis, and sensory branches to the fibula and the foot. The anomalous muscles around the lateral malleolus were also innervated by this nerve. Neither cutaneous branches nor communicating branches with other nerves were found. The present study reveals that the accessory deep peroneal nerve is consistently present and possesses a proper motor and sensory distribution in the lateral region of the leg and ankle. It is not an anomalous nerve as has previously been suggested.

Total innervation of the extensor digitorum brevis by the accessory deep peroneal nerve.

We describe a patient with complete (100%) innervation of the extensor digitorum brevis muscle by the accessory deep peroneal nerve, which resulted in an erroneous diagnosis of peroneal mononeuropathy.

Congenital tibial aplasia with preaxial polydactyly. A case report.

An anatomical study of a left lower limb with congenital tibial aplasia and preaxial polydactyly amputated at 10 months of age was carried out. The tibia was replaced by a fibrous band (a band of connective tissue) and there were four cuneiforms, six metatarsal bones and seven toes. The second metatarsal bone showed characteristics of the hallux. An intermuscular septum which showed an orifice for the anterior tibial artery was found on the medial side of the leg and foot. All the muscles of the leg and foot were present except for the tibialis posterior muscle, which was replaced by two atypical muscles. No muscular attachments reached the fibrous band. Several intertendinous connection bands were found. Also, an accessory muscular belly split from the tibialis anterior tendon and attached to the common flexor tendinous sheet of the foot. An unusual motor branch of the deep peroneal nerve ran together with this belly to supply the intrinsic muscles of the hallux. We also observed other minor anomalies of the nerve pattern. The arterial pattern was complete, except for some arteries which showed both an anomalous origin and course. The findings of this study suggest that the development of the skeletal elements plays an important role in the differentiation of the muscles, tendons, arteries and nerves. We postulate that a dysmorphogenic event involving the development of the tibial field of the limb could give rise to both defective histodifferentiation of the tibia and defective programmed cell death in the pre-hallucial anlage. These anomalies would determine secondary adaptations of muscles, tendons, vessels and nerves of the limb.