Fibular (Peroneal) Neuropathy

Foot drop in critically ill patients: a narrative review of an elusive complication with intricate implications for recovery and rehabilitation

Foot drop is a condition characterized by the inability to lift the foot upwards towards the shin bone. This condition may affect a proportion of critically ill patients, impacting on their recovery after the acute phase of the illness. The occurrence of foot drop in critical care patients may result from various underlying causes, including neurological injuries, muscular dysfunction, nerve compression, or vascular compromise. Understanding the etiology and assessing the severity of foot drop in these patients is essential for implementing appropriate management strategies and ensuring better patient outcomes. In this comprehensive review, we explore the complexities of foot drop in critically ill patients. We search for the potential risk factors that contribute to its development during critical illness, the impact it has on patients' functional abilities, and the various diagnostic techniques adopted to evaluate its severity. Additionally, we discuss current treatment approaches, rehabilitation strategies, and preventive measures to mitigate the adverse effects of foot drop in the critical care setting. Furthermore, we explore the roles of critical care physical therapists, neurologists, and other healthcare professionals in the comprehensive care of patients with foot drop syndrome and in such highlighting the importance of a multidisciplinary approach.

Electrodiagnostic studies and new diagnostic modalities for evaluation of peripheral nerve disorders

Electrodiagnostic studies (EDx) are frequently performed in the diagnostic evaluation of peripheral nerve disorders. There is increasing interest in the use of newer, alternative diagnostic modalities, in particular imaging, either to complement or replace established EDx protocols. However, the evidence to support this approach has not been expansively reviewed. In this paper, diagnostic performance data from studies of EDx and other diagnostic modalities in common peripheral nerve disorders have been analyzed and described, with a focus on radiculopathy, plexopathy, compressive neuropathies, and the important neuropathy subtypes of Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), vasculitic neuropathy and diabetic neuropathy. Overall EDx retains its place as a primary diagnostic modality in the evaluated peripheral nerve disorders. Magnetic resonance imaging and ultrasound have developed important complementary diagnostic roles in compressive and traumatic neuropathies and atypical CIDP, but their value is more limited in other neuropathy subtypes. Identification of hourglass constriction in nerves of patients with neuralgic amyotrophy may have therapeutic implications. Investigation of radiculopathy is confounded by poor correlation between clinical features and imaging findings and the lack of a diagnostic gold standard. There is a need to enhance the literature on the utility of these newer diagnostic modalities.

Case Report: Acute common peroneal nerve injury after posterior lumbar decompression surgery

Spine surgery is a prevalently performed procedure. Some authors have proposed an age-related surge in surgical and general complications. During spine surgery, patients are placed in positions that are not physiologic, would not be tolerated for prolonged periods by the patient in the awake state, and may lead to complications. Understanding these uncommon complications and their etiology is pivotal to prevention and necessary. The patient is a 76-year-old woman referred to the outpatient department of neurosurgery in February 2022 by her physiatrist with a chief complaint of chronic low back pain and numbness over the left leg. Lumbar spine magnetic resonance imaging revealed degenerative disc disease and posterior disc bulging at the levels of L2/3∼L5/S1 with compression of the thecal sac. After receiving anti-inflammatory medication, nerve block and caudal block, her symptoms persisted. She was referred to a neurosurgeon for surgical intervention. We diagnosed spinal stenosis with left L3 and L4 radiculopathy, and elective decompression surgery was scheduled a few days later. We performed discectomies at L2/3 and L3/4 and left unilateral laminectomy at L2 and L3 for bilateral decompression. Following an uneventful surgery, the patient was extubated, and her left leg pain improved, but pain over the right outer calf with drop foot developed. A second lumbar MRI the next day revealed no evidence of recurrent disc herniation or epidural hematoma. Then, she received nerve conduction velocity and needle electromyogram on postoperative day 2, and the studies indicated right common peroneal nerve entrapment neuropathy. After medication with steroids and foot splint use, right leg pain improved. However, weak dorsiflexion of the right ankle persisted. We referred this patient to a physiatrist and OPD for follow-up after discharge. Perioperative peripheral nerve injury (PPNI) is most commonly caused by peripheral nerve ischemia due to abnormal nerve lengthening or pressure and can be exacerbated by systemic hypotension. Any diseases affecting microvasculature and anatomical differences may contribute to nerve injury or render patients more susceptible to nerve injury. Prevention, early detection and intervention are paramount to reducing PPNI and associated adverse outcomes. The use of intraoperative neuromonitoring theoretically allows the surgical team to detect and intervene in impending PPNI during surgery.

Slimmer's Palsy Following Weight Loss Associated With Metastatic Breast Cancer: A Case Report

Common peroneal neuropathy (CPN), also known as Slimmer's Palsy, is an isolated peripheral neuropathy typically associated with rapid weight loss resulting in loss of adipose tissue and subsequent nerve compression at the fibular head and is up to three times more common in individuals with malignancy. In this case report, we describe the diagnosis of CPN in a 54-year-old female with a 2.5-month history of atraumatic left foot drop and left ankle paresthesias, preceded by a 35-40 pound weight loss over the prior 3.5 month period in the setting of metastatic breast cancer.

Acroparesthesias: An Overview

Acroparesthesia is a symptom characterized by a subjective sensation, such as numbness, tingling, prickling, and reduced sensation, affecting the extremities (fingers and toes). Despite its frequency, data regarding its diagnostic approach and management are scarce. The etiological diagnosis of acroparesthesia is sometimes challenging since it can be due to abnormality anywhere along the sensory pathway from the peripheral nervous system to the cerebral cortex. Acroparesthesia can reveal several diseases. It can be associated with rheumatic complaints such as arthritis or myalgia. Further cautions are required when paresthesia is acute (within days) in onset, rapidly progressive, severe, asymmetric, proximal, multifocal, or associated with predominant motor signs (limb weakness) or severe dysautonomia. Acroparesthesia may reveal Guillain-Barré syndrome or vasculitis, requiring rapid management. Acroparesthesia is a predominant symptom of polyneuropathy, typically distal and symmetric, often due to diabetes. However, it can occur in other diseases such as vitamin B12 deficiency, monoclonal gammopathy of undetermined significance, or Fabry's disease. Mononeuropathy, mainly carpal tunnel syndrome, remains the most common cause of acroparesthesia. Ultrasonography contributes to the diagnosis of nerve entrapment neuropathy by showing nerve enlargement, hypoechogenic nerve, and intraneural vascularity. Besides, it can reveal its cause, such as space-occupying lesions, anatomical nerve variations, or anomalous muscle. Ultrasonography is also helpful for entrapment neuropathy treatment, such as ultrasound-guided steroid injection or carpal tunnel release. The management of acroparesthesia depends on its causes. This article aimed to review and summarize current knowledge on acroparesthesia and its causes. We also propose an algorithm for the management of acroparesthesia.

Musculoskeletal manifestations of COVID-19

During the COVID-19 pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected millions of people worldwide, with acute respiratory distress syndrome (ARDS) being the most common severe condition of pulmonary involvement. Despite its involvement in the lungs, SARS-CoV-2 causes multiple extrapulmonary manifestations, including manifestations in the musculoskeletal system. Several cases involving bone, joint, muscle, neurovascular and soft tissues were reported shortly after pandemic onset. Even after the acute infection has resolved, many patients experience persistent symptoms and a decrease in quality of life, a condition known as post-COVID syndrome or long COVID. COVID-19 vaccines have been widely available since December 2020, preventing millions of deaths during the pandemic. However, adverse reactions, including those involving the musculoskeletal system, have been reported in the literature. Therefore, the primary goal of this article is to review the main imaging findings of SARS-CoV-2 involvement in the musculoskeletal system, including acute, subacute, chronic and postvaccination manifestations.

Diagnostic Approach to Lower Limb Entrapment Neuropathies: A Narrative Literature Review

Entrapment neuropathies of the lower limb are a misunderstood and underdiagnosed group of disorders, characterized by pain and dysesthesia, muscular weakness, and specific provoking movements on physical examination. The most frequent of these syndromes encountered in clinical practice are fibular nerve entrapment, proximal tibial neuropathy, sural nerve neuropathy, deep gluteal syndrome or sciatic nerve entrapment, and lateral femoral cutaneous nerve entrapment, also known as meralgia paresthetica. These are commonly mistaken for lumbar plexopathies, radiculopathies, and musculotendinous diseases, which appear even more frequently and have overlapping clinical presentations. A comprehensive anamnesis, physical examination, and electrodiagnostic studies should help clarify the diagnosis. If the diagnosis is still unclear or a secondary cause of entrapment is suspected, magnetic resonance neurography, MRI, or ultrasonography should be conducted to clarify the etiology, rule out other diseases, and confirm the diagnosis. The aim of this narrative review was to help clinicians gain familiarity with this disease, with an increase in diagnostic confidence, leading to early diagnosis of nerve damage and prevention of muscle atrophy. We reviewed the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and EDX technique and interpretation of the entrapment neuropathies of the lower limb, using articles published from 1970 to 2022 included in the Pubmed, MEDLINE, Cochrane Library, Google Scholar, EMBASE, Web of Science, and Scopus databases.

Pediatric Peroneal Nerve Palsy Secondary to Fibular Osteochondroma

Peripheral nerve injuries due to mass effect from bony lesions can occur when the nerve exists in an anatomically constrained location, such as the common peroneal nerve at the fibular head which passes into the tight fascia of the lateral leg compartment. We report a case of a pediatric patient who developed a common peroneal nerve palsy secondary to an osteochondroma of the fibular head and describe the clinical evaluation, radiographic findings, and surgical approach. Rapid diagnosis and nerve decompression after the onset of symptoms restored full motor function at the 8-month postoperative mark.

Common peroneal nerve injury after tibial plateau fractures: A case series

Introduction

Common peroneal nerve (CPN) injury is a rare but significant complication of knee trauma. Given its low incidence, there is limited published evidence, but reports have shown dislocations and fractures associated with varus deformity are more likely to injure the nerve, causing foot drop. This study aims to document the incidence and outcome of CPN palsy in tibial plateau fractures (TPF).

Methods

We reviewed 746 cases of tibial plateau fractures treated between 2011 and 2020. We analysed patients' demographics, injury mechanisms, clinical course, and complications, and identified those with CPN palsies. Fractures were classified using the Schatzker, Luo and AO/OTA systems. The details of the CPN injury, including nerve conduction studies, duration of symptoms and outcome were recorded.

Results

We identified 11 patients who had concurrent TPFs and CPN palsies, an overall incidence of 1.47 %. Most fractures involved the medial column (n = 9), with the C3 fragmentary TPF pattern being the most common (n = 4). The incidence of CPN injury was higher in medial fractures (5 %) and bicondylar fractures (3 %). We also found that most patients (n = 9) recovered full neurological function within 2 years.

Discussion

This is the first study looking at a patient cohort sustaining concurrent TPFs and CPN injuries. It is a rare complication but should be looked for in high-risk medial and bicondylar fractures. We found that prognosis is better in TPF-associated CPN palsy than in other knee trauma, and that the majority of patients can expect a full recovery of nerve function.

Gait analysis of leprosy patients with foot drop using principal component analysis

BACKGROUND

Peripheral nerve injury caused by leprosy can lead to foot drop, resulting in an altered gait pattern that has not been previously described using 3D gait analysis.

METHODS

Gait kinematics and dynamics were analyzed in 12 patients with unilateral foot drop caused by leprosy and in 15 healthy controls. Biomechanical data from patients' affected and unaffected limbs were compared with controls using inferential statistics and a standard distance, based on principal components analysis (PCA).

FINDINGS

Patients walked slower than controls (0.8 ± 0.2 vs. 1.1 ± 0.2 m/s, p = 0.003), with a reduced stance and increased swing percentage. The affected limb increased (p < 0.05) plantar flexion at the initial contact (-16.8^o ± 8.3), terminal stance (-29.1^o ± 11.5), and swing (-12.4^o ± 6.2) in the affected limb compared to unaffected (-6.6^o ± 10.3; -14.6^o ± 11.6; 2.4^o ± 7.6) and controls (-5.4^o ± 2.5; -18.8^o ± 5.8; -1.4^o ± 3.9). Increased pelvic tilt and knee adduction/abduction range, with lower hip adduction, were observed. The second peak of ground reaction force (98.6 ± 5.2 %BW), ankle torque (0.99 ± 0.33 Nm/kg), and net ankle work in stance (-0.03 ± 5.4 J/Kg) decreased in the affected limb compared to controls (104.1 ± 5.5 %BW; 1.24 ± 0.4 Nm/kg; -4.58 ± 5.19 J/kg; p < 0.05). There were decreasing multivariate standard distances in the affected limb compared with the unaffected and controls. PCA loading factors highlighted the major differences between groups.

INTERPRETATION

Leprosy patients with foot drop presented altered gait patterns in affected and unaffected limbs. There were remarkable differences in ankle kinematics and dynamics. Rehabilitation devices, such as ankle foot orthosis or tendon transfer surgeries to increase ankle dorsiflexion, could benefit these patients and reduce deviations from normal gait.

Repair of Long Peripheral Nerve Defects in Sheep: A Translational Model for Nerve Regeneration

Despite advances in microsurgery, full functional recovery of severe peripheral nerve injuries is not commonly attained. The sheep appears as a good preclinical model since it presents nerves with similar characteristics to humans. In this study, we induced 5 or 7 cm resection in the peroneal nerve and repaired with an autograft. Functional evaluation was performed monthly. Electromyographic and ultrasound tests were performed at 6.5 and 9 months postoperation (mpo). No significant differences were found between groups with respect to functional tests, although slow improvements were seen from 5 mpo. Electrophysiological tests showed compound muscle action potentials (CMAP) of small amplitude at 6.5 mpo that increased at 9 mpo, although they were significantly lower than the contralateral side. Ultrasound tests showed significantly reduced size of tibialis anterior (TA) muscle at 6.5 mpo and partially recovered size at 9 mpo. Histological evaluation of the grafts showed good axonal regeneration in all except one sheep from autograft 7 cm (AG7) group, while distal to the graft there was a higher number of axons than in control nerves. The results indicate that sheep nerve repair is a useful model for investigating long-gap peripheral nerve injuries.

The treatment effect of posterior lumbar fusion surgery on patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis

Purpose

The purpose of this study is to investigate the clinical effect of posterior lumbar fusion surgery on patients who suffer from lumbar disc herniation concurrent with peroneal nerve paralysis.

Methods

The patients suffering from peroneal nerve paralysis and undergoing posterior lumbar fusion surgery between January 2012 and December 2019 were retrospectively reviewed. The data of the identified patients were then collected and processed. All patients were followed up post-operatively after discharge from the hospital. The data was analyzed in terms of Oswestry disability index (ODI), visual analogue scale (VAS) score, and relative lower-limb muscle strength.

Results

A total of 87 patients (52 males and 35 females) aged 54 ± 11 years met the inclusion criteria for this study. These patients stayed in hospital for 16 ± 6 days and were followed up for 81 ± 24 months. Data analysis showed that muscle strength of the tibialis anterior and extensor digitorum significantly recovered at the last follow-up with a grade of 3 (median), compared to grade 0 at admission (p < 0.001). Furthermore, the median VAS score decreased to 1 at the last follow-up from 6 at admission (p < 0.001), and the ODI greatly improved with 10% (median) at the last follow-up, while it was 58% at admission (p < 0.001). The ODI improvement rate was 60% on average at the last follow-up. Multivariate regression analysis regarding the ODI and muscle strength improvement rates showed that advanced age was a risk factor for postoperative recovery.

Conclusions

Most of the patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis can improve after undergoing posterior lumbar fusion surgery, but few can reach full recovery. Advanced age might be a risk factor that affects the prognosis of these patients after surgery.

Neuropathic pain in peroneal nerve entrapment at the fibular head

BACKGROUND

Peroneal neuropathy at the fibular head (PNFH) is a mononeuropathy that typically presents with drop foot and sensory abnormalities over the skin area innervated by the peroneal nerve.

OBJECTIVE

The aim of the present study was to evaluate neuropathic pain in patients with PNFH.

METHODS

Patients with clinical and electrodiagnostic features consistent with PNFH associated with weight loss, leg postures, or prolonged sleep were included in the present retrospective cohort study. Nerve conduction studies were performed in the bilateral lower extremities of all patients. The Leeds assessment of neuropathic symptoms and signs scale (LANSS) was applied to all patients.

RESULTS

Thirty-two PNFH patients (78% males) were included in the study. The LANSS score in the majority of patients was lower than 12. There was 1 patient with a LANSS score of 12. The electrodiagnostic features of 16 patients were compatible with axonal degeneration. The mean LANSS scores of PNFH patients with and without axonal degeneration were 4.3 ± 3.7 and 5.2 ± 2.9, respectively (p = 0.255).

CONCLUSION

The present study showed that neuropathic pain is a rare symptom in patients with PNFH associated with weight loss, leg postures, or prolonged sleep.

Repair of Long Nerve Defects with a New Decellularized Nerve Graft in Rats and in Sheep

Decellularized nerve allografts (DC) are an alternative to autografts (AG) for repairing severe peripheral nerve injuries. We have assessed a new DC provided by VERIGRAFT. The decellularization procedure completely removed cellularity while preserving the extracellular matrix. We first assessed the DC in a 15 mm gap in the sciatic nerve of rats, showing slightly delayed but effective regeneration. Then, we assayed the DC in a 70 mm gap in the peroneal nerve of sheep compared with AG. Evaluation of nerve regeneration and functional recovery was performed by clinical, electrophysiology and ultrasound tests. No significant differences were found in functional recovery between groups of sheep. Histology showed a preserved fascicular structure in the AG while in the DC grafts regenerated axons were grouped in small units. In conclusion, the DC was permissive for axonal regeneration and allowed to repair a 70 mm long gap in the sheep nerve.

Neurological Complications Associated With SARS-CoV-2 Infection: A Single-Centre Experience

BACKGROUND

The clinical presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can range from mild or moderate disease (80% of the cases) to severe disease (15%) requiring oxygen support, and critical disease (5%), associated with acute respiratory distress syndrome and admission to the intensive care unit (ICU). In critically ill patients, prone positioning can be used to optimize oxygenation. Although there is a favourable response to this strategy, being a life-saving measure, additional associated complications may appear, including compressive neuropathies. Despite respiratory affection being more common, SARS-CoV-2 infection can also attack other systems and can, under certain conditions, affect the central or peripheral nervous system. It has been described that neurological manifestations can result from the neuroinvasive properties of the SARS-CoV-2 or as an indirect consequence of multiorgan dysfunction.

AIMS

We intend to report the patients who presented with neurological complications associated with coronavirus disease 2019 (COVID-19) and/or complications of its treatment, followed in our physical and rehabilitation medicine (PRM) service.

MATERIALS AND METHODS

A retrospective analysis of patients admitted to the PRM ward with outpatient consultation in the context of post-COVID-19 status between April 2020 and November 2021 (the period of the highest prevalence of infection) was carried out. Patients with neurological complications after SARS-CoV-2 infection and consequently a decline in previous functionality were identified.

RESULTS

Thirteen patients (23.6%) admitted to the PRM ward had peripheral neurological complications, documented by electroneuromyography, including Guillain-Barré syndrome, sensory-motor polyneuropathy, peroneal nerve injury, femoral nerve injury, and lumbar plexus injury. The neurological complications of the patients followed in a post-COVID-19 consultation were also evaluated. Eight patients (20%) reported neurological sequelae. Five patients presented peripheral nerve damage (peroneal, accessory, ulnar, and recurrent laryngeal) of undefined aetiology, diagnosed after the acute phase of hospitalization. Two patients had COVID-19 infection followed by ischemic stroke (vertebrobasilar and middle cerebral artery), requiring hospitalization in the acute phase. One patient had COVID-19 infection followed by longitudinal myelitis, with positive anti-myelin oligodendrocyte glycoprotein (MOG). All patients required follow-up by the rehabilitation team with partial recovery of deficits.

CONCLUSIONS

 All patients admitted to the PRM ward with neurological manifestations had critical disease and symptoms compatible with peripheral nervous system involvement. Patients admitted to the PRM consultation had different levels of viral disease severity and had sequelae related to peripheral and central nervous system disorders. Identifying the aetiology of these injuries is essential for us to act on their prevention, particularly with regard to indirect complications, such as compressive neuropathies. It will be necessary to maintain the follow-up of these patients to understand the evolution of the neurological consequences associated with COVID-19.

Biological Approach in the Treatment of External Popliteal Sciatic Nerve (Epsn) Neurological Injury: Review

The external popliteal sciatic nerve (EPSN) is the nerve of the lower extremity most frequently affected by compressive etiology. Its superficial and sinuous anatomical course is closely related to other rigid anatomical structures and has an important dynamic neural component. Therefore, this circumstance means that this nerve is exposed to multiple causes of compressive etiology. Despite this fact, there are few publications with extensive case studies dealing with treatment. In this review, we propose to carry out a narrative review of the neuropathy of the EPSN, including an anatomical reminder, its clinical presentation and diagnosis, as well as its surgical and biological approach. The most novel aspect we propose is the review of the possible role of biological factors in the reversal of this situation.

Childhood focal compressive mononeuropathies during the COVID-19 pandemic in Buenos Aires, Argentina

Introduction/Aims

Focal peripheral neuropathies are infrequently seen in pediatric patients. The COVID‐19 pandemic has disrupted normal life for many people, including complete lockdowns and school closing for long periods of time in many countries, which prompted children to stay at home. Our aim is to assess whether there has been an increased incidence of focal compressive peripheral neuropathies in the pediatric population during COVID‐19–associated lockdown.

Methods

Clinical, electrophysiological, and imaging characteristics were reviewed for patients referred to the electrodiagnostic (EDx) laboratory with suspicion of a focal neuropathy. The incidence of focal compressive peripheral neuropathies seen during the period of March to September 2020 was compared with the same time period in 2019.

Results

An increased incidence of focal neuropathies was seen in 2020 (31%) compared with 2019 (6.8%). During 2020, 7 fibular (peroneal) mononeuropathies and 2 ulnar neuropathies were diagnosed. Most patients with focal neuropathies were underweight and acknowledged prolonged screen time periods. Electrophysiological findings consisted of mostly demyelinating lesions with an overall good clinical outcome.

Discussion

In this study we raise awareness about a possible increased incidence of focal compressive peripheral neuropathies in children during COVID‐19–associated lockdown, which may be prevented with changing positions during sedentary activities.

An Update on Peroneal Nerve Entrapment and Neuropathy

Peroneal neuropathy is the most common compressive neuropathy of the lower extremity. It should be included in the differential diagnosis for patients presenting with foot drop, the pain of the lower extremity, or numbness of the lower extremity. Symptoms of peroneal neuropathy may occur due to compression of the common peroneal nerve (CPN), superficial peroneal nerve (SPN), or deep peroneal nerve (DPN), each with different clinical presentations. The CPN is most commonly compressed by the bony prominence of the fibula, the SPN most commonly entrapped as it exits the lateral compartment of the leg, and the DPN as it crosses underneath the extensor retinaculum. Accurate and timely diagnosis of any peroneal neuropathy is important to avoid progression of nerve injury and permanent nerve damage. The diagnosis is often made with physical exam findings of decreased strength, altered sensation, and gait abnormalities. Motor nerve conduction studies, electromyography studies, and diagnostic nerve blocks can also assist in diagnosis and prognosis. First-line treatments include removing anything that may be causing external compression, providing stability to unstable joints, and reducing inflammation. Although many peroneal nerve entrapments will resolve with observation and activity modification, surgical treatment is often required when entrapment is refractory to these conservative management strategies. Recently, additional options including microsurgical decompression and percutaneous peripheral nerve stimulation have been reported; however, large studies reporting outcomes are lacking.

Evidence in peroneal nerve entrapment: A scoping review

BACKGROUND AND PURPOSE

Daily management of patients with foot drop due to peroneal nerve entrapment varies between a purely conservative treatment and early surgery, with no high-quality evidence to guide current practice. Electrodiagnostic (EDX) prognostic features and the value of imaging in establishing and supplementing the diagnosis have not been clearly established.

METHODS

We performed a literature search in the online databases MEDLINE, Embase, and the Cochrane Library. Of the 42 unique articles meeting the eligibility criteria, 10 discussed diagnostic performance of imaging, 11 reported EDX limits for abnormal values and/or the value of EDX in prognostication, and 26 focused on treatment outcome.

RESULTS

Studies report high sensitivity and specificity of both ultrasound (varying respectively from 47.1% to 91% and from 53% to 100%) and magnetic resonance imaging (MRI; varying respectively from 31% to 100% and from 73% to 100%). One comparative trial favoured ultrasound over MRI. Variable criteria for a conduction block (>20%-≥50) were reported. A motor conduction block and any baseline compound motor action potential response were identified as predictors of good outcome. Based predominantly on case series, the percentage of patients with good outcome ranged 0%-100% after conservative treatment and 40%-100% after neurolysis. No study compared both treatments.

CONCLUSIONS

Ultrasound and MRI have good accuracy, and introducing imaging in the standard diagnostic workup should be considered. Further research should focus on the role of EDX in prognostication. No recommendation on the optimal treatment strategy of peroneal nerve entrapment can be made, warranting future randomized controlled trials.

Acute Common Peroneal Nerve Decompression After Total Knee Arthroplasty

Common peroneal nerve palsy (CPNP) after total knee arthroplasty has a reported incidence of 0.3% to 4% and can lead to foot drop, equinovarus deformity, and marked disability if not resolved. Patients typically present in the early postoperative period with weakness or inability to dorsiflex the ankle and decreased sensation of the dorsum of the foot. The authors report their experience, technique, and outcomes of acute peroneal decompression within the first 90 days postoperatively for 5 patients with this unique complication. Preoperatively, all patients had valgus deformity with intact dorsiflexion and sensation of the foot. The diagnosis of CPNP was made on postoperative day 0 or 1 in all cases. After diagnosis, patients were offered acute peroneal decompression and returned to the operating room electively. The surgical technique for dissection, release, and decompression of the nerve is described. At an average follow-up of 12 weeks (range, 6-16 weeks), all patients showed return of motor and sensory function, as tested by ankle dorsiflexion and dorsal foot sensation, with average motor strength of 4.6 of 5.3. Acute decompression of acute CPNP after total knee arthroplasty is a prudent treatment option that provides good functional results and rapid recovery. [Orthopedics. 2021;44(4):e556-e562.].

Transfer of the Posterior Tibial Tendon for Chronic Peroneal Nerve Palsy

»

The common peroneal nerve (CPN) is one of the most frequently injured nerves of the lower extremity.

»

One-third of patients who develop CPN palsy proceed to chronic impairment without signs of recovery.

»

Ankle-foot orthoses can provide improvement with respect to gait dysfunction and are useful as a nonsurgical treatment option.

»

Severe cases of CPN palsy demonstrating no signs of recovery may require operative intervention with tendon transfer.

COVID-19 Proned Ventilation and Its Possible Association With Foot Drop: A Case Series

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus causing the coronavirus disease 2019 (COVID-19) pandemic is known to lead to the complicated sequelae of severe acute respiratory distress syndrome. Proning has been used as an adjunctive treatment to improve oxygenation in both ventilated and non-ventilated patients. Although patients respond well to this strategy, complications from this arise as well. It is hypothesized that COVID-19 intensive care unit (ICU) proned ventilation is associated with new cases of foot drops or compressive unilateral ankle dorsiflexion weakness during the early 2020 COVID-19 pandemic. Five patients presented to an acute rehabilitation facility with unilateral ankle dorsiflexion weakness after ICU proned ventilation during the COVID-19 pandemic. Three patients were found to have primarily subacute left sensory-motor dysmyelinating common peroneal neuropathies located around the fibular head. Two patients were found to have primarily subacute sensory-motor dysmyelinating right-sided common peroneal neuropathies above the fibular head and distal to biceps femoris muscle. Compressive unilateral common peroneal neuropathies during the pandemic are possibly related to the impromptu, unconventional, and unfamiliar use of proned ventilation.

Branquinho M, Sousa AC, Zen F, Maurina M, Raimondo S, Mendonça C, Atayde L, Geuna S, Varejão AS, Maurício AC. Establishment of a Sheep Model for Hind Limb Peripheral Nerve Injury: Common Peroneal Nerve

Thousands of people worldwide suffer from peripheral nerve injuries and must deal daily with the resulting physiological and functional deficits. Recent advances in this field are still insufficient to guarantee adequate outcomes, and the development of new and compelling therapeutic options require the use of valid preclinical models that effectively replicate the characteristics and challenges associated with these injuries in humans. In this study, we established a sheep model for common peroneal nerve injuries that can be applied in preclinical research with the advantages associated with the use of large animal models. The anatomy of the common peroneal nerve and topographically related nerves, the functional consequences of its injury and a neurological examination directed at this nerve have been described. Furthermore, the surgical protocol for accessing the common peroneal nerve, the induction of different types of nerve damage and the application of possible therapeutic options were described. Finally, a preliminary morphological and stereological study was carried out to establish control values for the healthy common peroneal nerves regarding this animal model and to identify preliminary differences between therapeutic methods. This study allowed to define the described lateral incision as the best to access the common peroneal nerve, besides establishing 12 and 24 weeks as the minimum periods to study lesions of axonotmesis and neurotmesis, respectively, in this specie. The post-mortem evaluation of the harvested nerves allowed to register stereological values for healthy common peroneal nerves to be used as controls in future studies, and to establish preliminary values associated with the therapeutic performance of the different applied options, although limited by a small sample size, thus requiring further validation studies. Finally, this study demonstrated that the sheep is a valid model of peripheral nerve injury to be used in pre-clinical and translational works and to evaluate the efficacy and safety of nerve injury therapeutic options before its clinical application in humans and veterinary patients.

Peroneal Nerve Function Before and Following Surgical Excision of a Proximal Fibular Osteochondroma

BACKGROUND

Osteochondromas occur most commonly in the distal femur, proximal tibia, and humerus. There are no large studies reviewing the outcome of treatment for patients with an osteochondroma involving the proximal fibula. The purpose of this study is to specifically understand the manifestations of a proximal fibular osteochondroma (PFO) on the preoperative peroneal nerve function, and how surgical management of the osteochondroma affects function immediately postoperatively and at long-term follow-up.

METHODS

This is an institutional review board-approved retrospective review of a consecutive series of patients with a PFO treated operatively at a single institution. The medical record was carefully reviewed to identify demographic data, clinical data especially the status of the peroneal function at various time points.

RESULTS

There were 25 patients with 31 affected extremities who underwent surgical excision of the PFO at an average age of 12.4 years (range, 3.0 to 17.9 y). There were 16 males and 9 females. The underlying diagnosis was isolated PFO in 2 (8%) patients and multiple hereditary exostosis in 23 (92%) patients. Preoperatively, 9 (29%) had a foot drop and 22 (71%) did not. Those with a preoperative foot drop underwent surgery at a younger age (9.1 vs. 13.8 y) (P<0.004) and postoperatively 5 (55.5%) had complete resolution, 3 (33.3%) had improvement, and 1 (11.1%) persisted requiring an ankle foot orthosis. Of the 22 who were normal preoperatively, 5 (22.7%) developed an immediate postoperative foot drop, 3 (60%) completely resolved, 1 (20%) improved, and 1 (20%) persisted and was found to have a transected nerve at exploration. In total, 23 of the 25 (92%) patients who had a PFO excision, had a normal or near-normal peroneal nerve function including those who had poor function preoperatively.

CONCLUSIONS

Patients with a PFO have a preoperative peroneal nerve dysfunction 30% of the time and 23% of those who were normal preoperatively have postoperative dysfunction. Fortunately, nearly all patients have a complete recovery following excision of the osteochondroma.

LEVEL OF EVIDENCE

Level IV.

Peroneal Nerve Palsy due to Bulky Osteochondroma from the Fibular Head: A Rare Case and Literature Review

Common peroneal neuropathy is the most common compressive neuropathy in the lower extremities. The anatomical relationship of the fibular head with the peroneal nerve explains entrapment in this location. We report the case of a 14-year-old boy admitted with a left foot drop. The diagnosis was an osteochondroma of the proximal fibula compressing the common peroneal nerve. The patient underwent surgical decompression of the nerve and resection of the exostosis. Three months postoperatively, there was a complete recovery of the deficits. The association of osteochondroma and peroneal nerve palsy is rare. Early diagnosis is required in order to adjust the management and improve the results. It is worth to underscore that surgical resection is proven to be the appropriate treatment method ensuring high success rates.

Proximal tibiofibular joint changes after closed-wedge high tibial osteotomy. Are they relevant?

BACKGROUND

There is some controversy about how the proximal tibiofibular joint (PTFJ) capsulotomy changes PTFJ anatomy in closed-wedge high tibial osteotomy (CW-HTO) and about how this affects ankle and knee mobility and the onset of lateral knee pain. The aim of this study is to evaluate changes in PTFJ after CW-HTO, and its possible clinical significance.

METHODS

This study includes 50 patients who underwent CW-HTO with tibiofibular capsulotomy from 2000 to 2018 in our hospital. A clinical evaluation was conducted to evaluate pain location. The degrees of osteoarthritis and the proximal fibular subluxation were evaluated on radiographs. A dynamic analysis of the PTFJ was also performed comparing proximal fibular head subluxation on anteroposterior knee radiographs with the ankle placed in neutral position and dorsiflexed.

RESULTS

The clinical evaluation revealed that two patients had a sore scar, five had pain on the PTFJ with manual compression, and none referred lateral compartment pain. The radiological analysis revealed an average proximal subluxation of the fibular head after the osteotomy of 9.64 (range: 0-29) mm, which was greater in oblique PTFJ (p < 0.05). After the surgery, all the patients developed some degree of PTFJ arthritis. There was no correlation between lateral pain and proximal fibular subluxation, tibiofibular arthritis, or lateral compartment arthritis. The dynamic analysis revealed no significant changes.

CONCLUSIONS

After CW-HTO all the patients developed proximal subluxation of the fibular head and a variable degree of PTFJ osteoarthritis, but these changes seem to be unrelated with lateral knee pain.

A simple test to assist with the diagnosis of common fibular nerve entrapment and predict outcomes of surgical decompression

BACKGROUND

Common fibular (peroneal) nerve (CFN) entrapment is the most frequent nerve entrapment in the lower extremity. It can cause pain, sensory abnormalities, and reduced ability to dorsiflex the foot or a drop foot. A simple test to assist with diagnosis of CFN entrapment is described as an adjunctive clinical tool for the diagnosis of CFN entrapment and also as a predictor of successful surgical decompression of a CFN entrapment.

METHODS

The test, a lidocaine injection into the peroneus longus muscle at the site of a common fibular nerve entrapment, was studied retrospectively in 21 patients who presented with a clinical suspicion of CFN entrapment. Patients ages ranged from 17 to 71 (mean 48.5).

RESULTS

The lidocaine injection test (LIT) was positive in 19 patients, and of these, 17 underwent surgical decompression and subsequently experienced improved ability to dorsiflex their foot and reduced sensory abnormalities.

CONCLUSION

The LIT is a simple, safe adjunctive test to help diagnose and also predict a successful outcome of surgical decompression of a CFN entrapment. The proposed mechanism of action of the LIT could lead to new, non-surgical treatments for CFN entrapment.

Identifying Common Peroneal Neuropathy before Foot Drop

BACKGROUND

Common peroneal neuropathy shares the same pathophysiology as carpal tunnel syndrome. However, management is often delayed because of the traditional misconception of recognizing foot drop as the defining symptom for diagnosis. The authors believe recognizing common peroneal neuropathy before foot drop can relieve pain and help improve quality of life.

METHODS

One hundred eighty-five patients who underwent surgical common peroneal neuropathy decompression between 2011 and 2017 were included. The mean follow-up time was 249 ± 28 days. Patients were classified into two stages of severity based on clinical presentation: pre-foot drop and overt foot drop. Demographics, presenting symptoms, clinical signs, electrodiagnostic studies and response to surgery were compared between these two groups. Multivariate regression analysis was used to identify variables that predicted outcome following surgery.

RESULTS

Overt foot drop patients presented with significantly lower preoperative motor function (percentage of patients with Medical Research Council grade ≤ 1: overt foot drop, 90 percent; pre-foot drop, 0 percent; p < 0.001). Pre-foot drop patients presented with a significantly higher preoperative pain visual analogue scale score (pre-foot drop, 6.2 ± 0.2; overt foot drop, 4.6 ± 0.3; p < 0.001) and normal electrodiagnostic studies (pre-foot drop, 31.4 percent; overt foot drop, 0.1 percent). Postoperatively, both groups of patients showed significant improvement in quality-of-life score (pre-foot drop, 2.6 ± 0.3; overt foot drop, 2.7 ± 0.3). Patients with obesity or a traumatic cause for common peroneal neuropathy were less likely to have improvements in quality of life after surgical decompression.

CONCLUSION

Increased recognition of common peroneal neuropathy can aid early management, relieve pain, and improve quality of life.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Subclinical Peroneal Neuropathy Affects Ambulatory, Community-Dwelling Adults and Is Associated with Falling

BACKGROUND

Peroneal neuropathy with an overt foot drop is a known risk factor for falling. Subclinical peroneal neuropathy caused by compression at the fibular neck is subtler and does not have foot drop. A previous study found subclinical peroneal neuropathy in 31 percent of hospitalized patients. This was associated with having fallen. The purpose of this study was to determine the prevalence of subclinical peroneal neuropathy in ambulatory adults and investigate if it is associated with falling.

METHODS

A cross-sectional study of 397 ambulatory adults presenting to outpatient clinics at a large academic hospital was conducted from 2016 to 2017. Patients were examined for dorsiflexion weakness and signs of localizing peroneal nerve compression to the fibular neck. Fall risk was assessed with the Activities-Specific Balance Confidence Scale and self-reported history of falling. Multivariate logistic regression was used to correlate subclinical peroneal neuropathy with fall risk and a history of falls.

RESULTS

The mean patient age was 54 ± 15 years and 248 patients (62 percent) were women. Thirteen patients (3.3 percent) were found to have subclinical peroneal neuropathy. After controlling for various factors known to increase fall risk, patients with subclinical peroneal neuropathy were 3.74 times (95 percent CI, 1.06 to 13.14) (p = 0.04) more likely to report having fallen multiple times in the past year than patients without subclinical peroneal neuropathy. Similarly, patients with subclinical peroneal neuropathy were 7.22 times (95 percent CI, 1.48 to 35.30) (p = 0.02) more likely to have an elevated fall risk on the Activities-Specific Balance Confidence fall risk scale.

CONCLUSION

Subclinical peroneal neuropathy affects 3.3 percent of adult outpatients and may predispose them to falling.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Communications between the superficial and deep fibular nerves in the foot: An anatomical and electrophysiological study

INTRODUCTION

The deep fibular sensory nerve can be recorded to evaluate for peripheral nerve injury; however, it can be challenging in some individuals. Anatomic variation could account for some of this difficulty. Cadaver dissection and electrophysiological testing were used to characterize deep and superficial fibular sensory nerve supply to the foot.

MATERIALS AND METHODS

Nineteen feet from 15 (8 males and 7 females) cadavers were dissected to identify the deep fibular nerves (DFNs) and superficial fibular nerves (SFNs). Sensation to the first dorsal web space was tested electrophysiologically in 101 participants (31 males and 70 females) with an age range of 18-47 years with stimulation over both DFNs and SFNs.

RESULTS

Eleven of the 19 (58%) cadaver limbs had a communication between SFNs and DFNs in the dorsum of the foot. A reliable sensory response was recorded in the first dorsal web space in 88% of the limbs tested. Deep fibular stimulation alone produced a response in 34% of the limbs, while superficial fibular stimulation alone produced a response in 10% of the limbs. A separate response with stimulation of both the DFNs and SFNs was recorded in 44% of the limbs.

CONCLUSIONS

A functional superficial to deep fibular sensory communication is present in a significant portion of the population. Those with the communication may not have the isolated sensory loss that would be expected in the first dorsal web space in conditions impacting the DFNs.

Ultrasound-guided treatment of common peroneal neuropathy caused by Baker's cyst: a clinical note - A case report

Background

Baker's cysts are usually located in the posteromedial side of the knee and seldom cause neuropathy.

Case

We describe the rare case of a 57-year-old woman with a popliteal cyst who presented with limping gait and pain in her lower leg. She was electronically diagnosed with common peroneal neuropathy and transferred to our pain clinic. On ultrasound examination, about 2.0 × 1.2 cm sized popliteal cyst was found to extend to the fibular head, compressing the common peroneal nerve. Therefore, ultrasound-guided aspiration of the cyst and a common peroneal nerve block were performed. Immediately after the procedure, the pain, dysesthesia, and limping gait were relieved. Although her pain and dysesthesia were relieved, she underwent the surgery because of limping gait.

Conclusions

In this case, we found the Baker's cyst, the cause of the common peroneal neuropathy, and treated it immediately by just simple ultrasound examination and aspiration.

Resolution of Preoperative Peroneal Nerve Palsy After Total Knee Arthroplasty: A Case Report

CASE

We present the case of a 71-year-old man with right knee osteoarthritis (OA) and a varus deformity who developed a progressive common peroneal nerve palsy that resolved after total knee arthroplasty (TKA). After decades of knee pain, the patient gradually developed a foot drop as well as numbness and paresthesias over the foot dorsum during the course of 1 month. The patient underwent TKA and within 6 weeks postoperatively had complete resolution of the peroneal nerve symptoms.

CONCLUSION

A progressive common peroneal palsy in advanced varus knee OA may resolve after a properly aligned TKA without nerve decompression.

Indications for neuromuscular ultrasound: Expert opinion and review of the literature

Over the last two decades, dozens of applications have emerged for ultrasonography in neuromuscular disorders. We wanted to measure its impact on practice in laboratories where the technique is in frequent use. After identifying experts in neuromuscular ultrasound and electrodiagnosis, we assessed their use of ultrasonography for different indications and their expectations for its future evolution. We then identified the earliest papers to provide convincing evidence of the utility of ultrasound for particular indications and analyzed the relationship of their date of publication with expert usage. We found that experts use ultrasonography often for inflammatory, hereditary, traumatic, compressive and neoplastic neuropathies, and somewhat less often for neuronopathies and myopathies. Usage significantly correlated with the timing of key publications in the field. We review these findings and the extensive evidence supporting the value of neuromuscular ultrasound. Advancement of the field of clinical neurophysiology depends on widespread translation of these findings.

External neurolysis as a treatment for foot drop secondary to weight loss: a retrospective analysis of 200 cases

BACKGROUND

Peroneal nerve entrapment is the most common peripheral mononeuropathy of the lower limbs. Foot drop, a common presentation, leads to an impaired eversion and dorsiflexion of the foot. An intriguing observation is the occurrence of foot drop secondary to weight loss.

METHODS

A retrospective study of patients surgically treated for peroneal nerve entrapment was performed between January 1, 1995 and December 31, 2016, at the Department of Neurosurgery, Genk, Belgium. Out of a total of 421 patients, 200 patients with foot drop secondary to weight loss were included. For each subject, motor and sensory outcomes after external neurolysis were investigated. As a primary objective, we examined the postoperative outcomes of external neurolysis as a treatment for foot drop in patients with peroneal nerve entrapment at the fibular head secondary to weight loss. As a secondary objective, we analyzed the correlation between patient characteristics and the success rate of external neurolysis.

RESULTS

When defining success as a postoperative MRC score of 4 or 5, external neurolysis has a success rate of 85% in patients with foot drop secondary to weight loss. A significant difference (P = < 0.0001) between postoperative and preoperative MRC scores indicates that external neurolysis leads to significant improvement of motor function in patients with foot drop secondary to weight loss. A multiple logistic regression model showed that "preoperative MRC scores" and "duration of symptoms" were the only variables with an impact on postoperative MRC scores. Other variables such as "age," "gender," and "side of entrapment" had no significant impact on postoperative results.

CONCLUSIONS

Statistical analysis emphasizes the important role of external neurolysis in the treatment of peripheral peroneal nerve entrapment. Therefore, external neurolysis at the fibular head should be regarded as a very effective and safe procedure in patients with foot drop secondary to weight loss.

Causes of peroneal neuropathy associated with orthopaedic leg lengthening in different canine models

Peroneal neuropathy is one of the complications of orthopaedic leg lengthening. Methods of treatment include slowing of distraction and decompression both of which may lead to additional complications. The purpose of this study was to analyse the changes in histologic peroneal nerve structure during experimental orthopaedic lengthening using various modes of manual or automatic distraction. The obtained data provide the basis for better understanding of peroneal neuropathy pathogenesis and refinement of prophylaxis and preventive treatment protocols. Four experimental models of canine leg lengthening using the Ilizarov fixator were studied: 1 (n = 10)—manual distraction—1 mm/day divided into four increments; 2 (n = 12)—automatic distraction—1 mm/day in 60 increments, 3 (n = 9) and 4 (n = 9)—increased rate of high frequency automatic distraction: 3 mm/day in 120 and 180 increments, respectively. In peroneal nerves semi-thin sections cross-sectional fascicular areas, content of adipocytes in epineurium, endoneurial vascularisation, morphometric parameters of nerve fibres were assessed by computerised analysis at the end of distraction and of consolidation periods and 30 days after fixator removal. In Groups 1–2 massive nerve fibre degeneration along with epineural vessels obliteration was revealed in two cases from 22, whereas in Groups 3–4 there were 10 from 18 (p < 0.01). Injuries of perineurium and endoneurial vessels were noted in Group 3, and long-lasting thinning of nerve fascicles in Group 4. The decrease in epineurial fat tissue was revealed in all groups, more drastic in 3. Modifications and injuries of nerve sheaths and blood vessels depending on distraction rate and frequency contribute to peroneal neuropathy. Its mechanical, circulatory and metabolic causes are discussed.

Deep peroneal nerve palsy due to osteochondroma arising from fibular head and proximal lateral tibia

•

Osteochondroma are the most common benign tumors.

•

Disease affecting knee joint in 94% of all cases.

•

Clinicians should be aware of the possible tumoral lesions in drop foot etiology.

Following median and ulnar nerves, peroneal nerve entrapment is the most frequent nerve involvement in the body Katirji and Wilbourn (1998) [1].

Osteochondromas are the most common benign bone tumors comprising 9% of all bone tumors and 35% of benign bone tumors Porter (2000) [2].

Hereditary exostoses (HME) is an autosomal dominant disorder with variable penetrance characterized by multiple osteochondromas near joints. It is one of the most commonskeletal dysplasias with a frequency of about 1.18%.

In this study, we aimed to present a case with a drop foot resulting from osteochondromas of proximal tibia and fibula and help to guide the clinicians in differential diagnosis according to SCARE criteria Agha (2016) [3].

Evidence for small fiber neuropathy in early Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) is neurodegenerative movement disorder affecting primarily the central nervous system with several recognized non-motor symptoms that can occur at various stages of the disease. Recently it has been shown that patients with PD may be prone to peripheral nervous system pathology in the form of a peripheral neuropathy (PN). It is unclear if PN is an inherent feature of PD or if it is an iatrogenic effect of the mainstay PD treatment Levodopa.

METHODS

To determine if peripheral neuropathy occurs in early untreated PD we employed a case-control study design using gold standard tests for PN, including neurological examination according to the Utah Early Neuropathy Scale (UENS) and nerve conduction studies, as well as new, more sensitive and informative tests for PN including the skin biopsy and corneal confocal microscopy (CCM).

RESULTS

We studied 26 patients with PD and 22 controls using the neurological examination and nerve conduction studies (NCS) and found no significant difference between groups except for some reduced vibration sense in the PD group. Epidermal nerve densities in the skin biopsies were similar between our cohorts. However, using CCM - a more sensitive test and a surrogate marker of small fiber damage in PN, we found that patients with PD had significantly reduced corneal nerve fiber densities and lengths as compared to controls.

CONCLUSIONS

We conclude that our positive CCM results provide evidence of preclinical PN in newly diagnosed PD patients.