Patient outcome after common peroneal nerve decompression

Outcomes of Common Peroneal Nerve Decompression

PURPOSE

Common peroneal nerve (CPN) neuropathy is the most common lower extremity mononeuropathy. When delayed or no recovery from CPN neuropathy is suspected, surgical CPN decompression (CPND) is considered to relieve symptoms. This study aimed to evaluate patient outcomes post-CPND performed by a single surgeon at a tertiary medical center.

METHODS

Patient outcomes after CPND performed by a single surgeon were reviewed. Motor, sensation, and pain scores post-CPND were assessed in 47 of the 46 patients. Patient demographics, including age, concomitant morbidities, time from injury to surgery, and body mass index (BMI), were also analyzed for correlations with outcomes after CPND by logistic regression.

RESULTS

29/34 patients with impaired motor function improved by at least one motor grade, 19/42 with altered sensation reported restored normal sensation, and 31/37 reported improved pain after CPND. No correlation of patient demographic factors with motor or pain improvement after CPND was observed. However, a BMI greater than 29.15 and a time between injury and surgery exceeding 506 days were associated with lower odds of reporting restored sensation.

CONCLUSIONS

Operative decompression of CPN neuropathy improves objective motor scores and subjective sensation and pain scores.

Electrical Stimulation Use in Upper Extremity Peripheral Nerve Injuries

Peripheral nerve injuries can be debilitating and often have a variable course of recovery. Electrical stimulation (ES) has been used as an intervention to attempt to overcome the limits of peripheral nerve surgery and improve patient outcomes after peripheral nerve injury. Little has been written in the orthopaedic literature regarding the use of this technology. The purpose of this review was to provide a focused analysis of past and current literature surrounding the utilization of ES in the treatment of various upper extremity peripheral nerve pathologies including compression neuropathies and nerve transection. We aimed to provide clarity on the clinical benefits, appropriate timing for its employment, risks and limitations, and the need for future studies of ES.

Unusual entrapment symptomatology treated in 115 cases by neurolysis of the common fibular nerve at the fibular head combined with neurolysis of the posterior tibial nerve at the tarsal tunnel

INTRODUCTION

Entrapment of the common fibular nerve (CFN) at the head of the fibula and entrapment of the posterior tibial nerve (PTN) at the tarsal tunnel are the most common nerve entrapment syndromes in the lower limb. Our aim was to study the results of combined neurolysis of the CFN and PTN for chronic lower limb pain. We hypothesized that combined neurolysis allowed a reduction of this chronic pain.

MATERIAL AND METHOD

This bi-centric retrospective study took place from January 2015 to November 2018, with a single senior surgeon. The inclusion criteria were all patients operated on for an idiopathic entrapment syndrome with neurolysis of the PTN at the tarsal tunnel, combined with neurolysis of the CFN at the head of the fibula. The primary endpoint was the pain evolution assessed on a numerical analogue scale (NAS) preoperatively and postoperatively on D+21, and at the last follow-up. The secondary endpoint was to determine the prognostic factors on the clinical outcome of neurolysis.

RESULTS

One hundred and fifteen neurolysis were included, comprising 64 women and 38 men with a mean age of 57±17.6 years. The preoperative pain (NAS0) was evaluated at 6±2.4 points. At D+21 postoperatively, there was a significant reduction in pain (NASD+21: 3±2.6 points, p<0.01). Similarly, at the last follow-up (with a mean follow-up of 37±8.4 months), there was a significant reduction in pain (NASLFU: 2±2.5, p<0.01). A history of systemic inflammatory disease was the only factor associated with a less significant decrease in pain at D+21, according to a multivariate analysis (p<0.01). There were 14 complications (12%) not requiring revision surgery.

CONCLUSION

This study is the first to demonstrate the efficacy of combined neurolysis of the CFN at the head of the fibula and the PTN at the tarsal tunnel, in the treatment of idiopathic nerve entrapment syndrome of the lower limb.

LEVEL OF EVIDENCE

IV; Retrospective comparative study.

Mechanomyography as a Surgical Adjunct for Treatment of Chronic Entrapment Neuropathy: A Case Series

BACKGROUND

Chronic entrapment neuropathy results in a clinical syndrome ranging from mild pain to debilitating atrophy. There remains a lack of objective metrics that quantify nerve dysfunction and guide surgical decision-making. Mechanomyography (MMG) reflects mechanical motor activity after stimulation of neuromuscular tissue and may indicate underlying nerve dysfunction.

OBJECTIVE

To evaluate the role of MMG as a surgical adjunct in treating chronic entrapment neuropathies.

METHODS

Patients 18 years or older with cubital tunnel syndrome (n = 8) and common peroneal neuropathy (n = 15) were enrolled. Surgical decompression of entrapped nerves was performed with intraoperative MMG of the hypothenar and tibialis anterior muscles. MMG stimulus thresholds (MMG-st) were correlated with compound muscle action potential (CMAP), motor nerve conduction velocity, baseline functional status, and clinical outcomes.

RESULTS

After nerve decompression, MMG-st significantly reduced, the mean reduction of 0.5 mA (95% CI: 0.3-0.7, P < .001). On bivariate analysis, MMG-st exhibited significant negative correlation with common peroneal nerve CMAP ( P < .05), but no association with ulnar nerve CMAP and motor nerve conduction velocity. On preoperative electrodiagnosis, 60% of nerves had axonal loss and 40% had conduction block. The MMG-st was higher in the nerves with axonal loss as compared with the nerves with conduction block. MMG-st was negatively correlated with preoperative hand strength (grip/pinch) and foot-dorsiflexion/toe-extension strength ( P < .05). At the final visit, MMG-st significantly correlated with pain, PROMIS-10 physical function, and Oswestry Disability Index ( P < .05).

CONCLUSION

MMG-st may serve as a surgical adjunct indicating axonal integrity in chronic entrapment neuropathies which may aid in clinical decision-making and prognostication of functional outcomes.

Complete Foot Drop With Normal Electrodiagnostic Studies: Sunderland "Zero" Ischemic Conduction Block of the Common Peroneal Nerve

ABSTRACT

Common peroneal neuropathy is a peripheral neuropathy of multifactorial etiology often left undiagnosed until foot drop manifests and electrodiagnostic abnormalities are detected. However, reliance on such striking symptoms and electrodiagnostic findings for diagnosis stands in contrast to other commonly treated neuropathies, such as carpal tunnel and cubital tunnel syndrome. Poor recognition of common peroneal neuropathy without foot drop or the presence of foot drop with normal electrodiagnostic studies thus often results in delayed or no surgical treatment. Our cases document 2 patients presenting with complete foot drop who had immediate resolution after decompression. The first patient presented with normal electrodiagnostic studies representing an isolated Sunderland Zero nerve ischemia. The second patient presented with severe electrodiagnostic studies but also had an immediate improvement in their foot drop representing a Sunderland VI mixed nerve injury with a significant contribution from an ongoing Sunderland Zero ischemic conduction block. In support of recent case series, these patients demonstrate that common peroneal neuropathy can present across a broad diagnostic spectrum of sensory and motor symptoms, including with normal electrodiagnostic studies. Four clinical subtypes of common peroneal neuropathy are presented, and surgical decompression may thus be indicated for these patients that lack the more conventional symptoms of common peroneal neuropathy.

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.

Clinical Outcomes After Neurolysis for the Treatment of Peroneal Nerve Palsy: A Systematic Review and Meta-Analysis

BACKGROUND

Neurolysis techniques have been adapted for decompression of peripheral nerves in multiple locations, including the common peroneal nerve (CPN) at the fibular neck. The aim of this study was to conduct a systematic review and meta-analysis to summarize the clinical outcomes of neurolysis for the management of peroneal nerve palsy (PNP).

METHODS

Preferred Reporting Systems for Systematic Reviews and Meta-Analyses guidelines were followed for this meta-analysis. Four databases were queried, and randomized clinical trials, cohort studies, case-control studies, and case series with n > 10 published in English that evaluated clinical outcomes of neurolysis for the treatment of PNP and foot drop were included. Two reviewers completed screening and data extraction. Methodological quality was evaluated using the Newcastle-Ottawa Scale.

RESULTS

A total of 493 articles were identified through literature search. Title and abstract screening identified 39 studies for full-text screening. Ten articles met the inclusion criteria for qualitative analysis, and 8 had complete data for meta-analysis.Overall, there were 368 patients (370 nerves) who had neurolysis of the CPN for PNP, of which 59.2% (n = 218) were men and 40.8% (n = 150) were women. The mean age of the patients was 47.1 years (SD, 10.0 years), mean time to surgery was 9.65 months (SD, 6.3 months), and mean follow-up time was 28 months (SD, 14.0 months). The median preoperative Medical Research Council (MRC) score was 1 (IQR 0, 3), with 42.2% (n = 156) having MRC score of 0. The median postoperative MRC score was 5 (IQR 4, 5), with 53.9% (n = 199) having MRC score of 5. Complications of neurolysis of the peroneal nerve for treatment of PNP included postoperative infection (0.54%, n = 2), wound dehiscence (0.27%, n = 1), hematoma (0.54%, n = 2), bleeding (0.27%, n = 1), relapse of PNP (0.27%, n = 1), and 1 case of mortality due to sepsis.

CONCLUSIONS

Our meta-analysis shows that neurolysis of the CPN is safe and improves ankle dorsiflexion strength in patients with PNP. Future studies should use a standardized method of measuring sensory outcomes, and studies of higher levels of evidence are needed to better assess the clinical outcomes of neurolysis for treatment of PNP.

Transfer of the Posterior Tibial Tendon for Chronic Peroneal Nerve Palsy

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

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

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

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

Surgical treatment of common peroneal neuropathy in schwannomatosis: illustrative cases

BACKGROUND

Neurofibromatosis syndromes such as neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis often result in painful symptoms related to tumor burden.

OBSERVATIONS

Painful symptoms classically associated with common points of peripheral nerve entrapment, such as common peroneal neuropathy at the fibular tunnel, may present in patients both with and without focal tumor involvement.

LESSONS

Surgical decompression at the point of entrapment, with or without resection of tumor, may provide symptomatic relief. Examples of surgical decompression at the point of entrapment, both with and without resection of tumor, are presented.

Reduction and fixation of high-energy proximal tibiofibular joint dislocations: a technical trick

We present our technique for screw stabilization and our clinical experience treating a series of patients presenting with proximal tibiofibular joint fracture-dislocations.

Partial tibial nerve transfer for foot drop from deep peroneal palsy: Lessons from three pediatric cases

Peroneal nerve palsy with resultant foot drop has significant impacts on gait and quality of life. Traditional management includes ankle-foot-orthosis, tendon transfer, and arthrodesis-each with certain disadvantages. While nerve transfers for peroneal nerve injury have been reported in adults, with variable results, they have not been described in the pediatric population. We report the use of partial tibial nerve transfer for foot drop from deep peroneal nerve palsy in three pediatric patients. The first sustained a partial common peroneal nerve laceration and underwent transfer of a single tibial nerve branch to deep peroneal nerve 7 months after injury. Robust extensor hallucis longus and extensor digitorum longus reinnervation was obtained without satisfactory tibialis anterior function. The next patient sustained a thigh laceration with partial sciatic nerve injury and underwent transfer of two tibial nerve branches directly to the tibialis anterior component of deep peroneal nerve 9 months after injury. The final patient sustained a blast injury to the posterior knee and similarly underwent a double fascicular transfer directly to tibialis anterior 4 months after injury. The latter two patients obtained sufficient strength (MRC 4-5) at 1 year to discontinue orthosis. In all patients, we used flexor hallucis longus and/or flexor digitorum longus branches as donors without postoperative loss of toe flexion. Overall, our experience suggests that early double fascicular transfer to an isolated tibialis anterior target, combined with decompression, could produce robust innervation. Further study and collaboration are needed to devise new ways to treat lower extremity nerve palsies.

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.

Chronic Lower Leg Pain in Athletes: Overview of Presentation and Management

BACKGROUND

Athletes with chronic lower leg pain present a diagnostic challenge for clinicians due to the differential diagnoses that must be considered.

PURPOSE/QUESTIONS

We aimed to review the literature for studies on the diagnosis and management of chronic lower leg pain in athletes.

METHODS

A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The PubMed, Scopus, and Cochrane library databases were searched, and articles that examined chronic lower leg pain in athletes were considered for review. Two independent reviewers conducted the search utilizing pertinent Boolean operations.

RESULTS

Following two independent database searches, 275 articles were considered for initial review. After the inclusion and exclusion criteria were applied, 88 were included in the final review. These studies show that the most common causes of lower leg pain in athletes include medial tibial stress syndrome, chronic exertional compartment syndrome, tibial stress fractures, nerve entrapments, lower leg tendinopathies, and popliteal artery entrapment syndrome. Less frequently encountered causes include saphenous nerve entrapment and tendinopathy of the popliteus. Conservative management is the mainstay of care for the majority of cases of chronic lower leg pain; however, surgical intervention may be necessary.

CONCLUSIONS

Multiple conditions may result in lower leg pain in athletes. A focused clinical history and physical examination supplemented with appropriate imaging studies can guide clinicians in diagnosis and management. We provide a table to aid in the differential diagnosis of chronic leg pain in the athlete.

[Chronic lower leg pain: entrapment of common peroneal nerve or tibial nerve-German version]

Young individuals with chronic exercise-induced lower leg pain (ELP) who have normal compartmental muscle pressures and normal imaging occasionally suffer from a nerve entrapment syndrome. These patients have consistently undergone a variety of diagnostic tests and often futile therapies prior to arriving at the correct diagnosis. Awareness among traumatologists regarding these nerve entities is low. A lower leg discomfort that is frequently present at night but worsens during exercise combined with altered foot skin sensations suggests an entrapment of the common peroneal or tibial nerve. If conservative therapies fail, neurolysis is advised.

Chronic lower leg pain: entrapment of common peroneal nerve or tibial nerve

Young individuals with chronic exercise-induced lower leg pain (ELP) who have normal compartmental muscle pressures and normal imaging occasionally suffer from a nerve entrapment syndrome. These patients have consistently undergone a variety of diagnostic tests and often futile therapies prior to arriving at the correct diagnosis. Awareness among traumatologists regarding these nerve entities is low. A lower leg discomfort that is frequently present at night but worsens during exercise combined with altered foot skin sensations suggests an entrapment of the common peroneal or tibial nerve. If conservative therapies fail, neurolysis is advised.

Microneurosurgical treatment options in peripheral nerve compression syndromes after chemotherapy and radiation treatment

Chemotherapy-induced peripheral neuropathy and radiation-induced brachial plexopathy are extremely debilitating conditions which can occur after treatment of malignancy. Unfortunately, the diagnosis can be elusive, and this dilemma is further compounded by the lack of efficacious therapeutics to prevent the onset of neurotoxicity before initiating chemotherapy or radiation or to treat these sequelae after treatment. However, microsurgical nerve decompression can provide these patients with a viable option to treat this complication.

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.

Common Entrapment Neuropathies

PURPOSE OF REVIEW

This article addresses relevant peripheral neuroanatomy, clinical presentations, and diagnostic findings in common entrapment neuropathies involving the median, ulnar, radial, and fibular (peroneal) nerves.

RECENT FINDINGS

Entrapment neuropathies are a common issue in general neurology practice. Early diagnosis and effective management of entrapment mononeuropathies are essential in preserving limb function and maintaining patient quality of life. Median neuropathy at the wrist (carpal tunnel syndrome), ulnar neuropathy at the elbow, radial neuropathy at the spiral groove, and fibular neuropathy at the fibular head are among the most frequently encountered entrapment mononeuropathies. Electrodiagnostic studies and peripheral nerve ultrasound are employed to help confirm the clinical diagnosis of nerve compression or entrapment and to provide precise localization for nerve injury. Peripheral nerve ultrasound demonstrates nerve enlargement at or near sites of compression.

SUMMARY

Entrapment neuropathies are commonly encountered in clinical practice. Accurate diagnosis and effective management require knowledge of peripheral neuroanatomy and recognition of key clinical symptoms and findings. Clinical diagnoses may be confirmed by diagnostic testing with electrodiagnostic studies and peripheral nerve ultrasound.

A nationwide analysis of 30-day adverse events, unplanned readmission, and length of hospital stay after peripheral nerve surgery in extremities and the brachial plexus

Background

Little is known on adverse events and their timing after peripheral nerve surgery in extremities. The aim of this study is to identify predictors and typical timing of complications, unplanned readmission, and length of hospital stay for patients undergoing peripheral nerve surgery in the extremities.

Methods

Data were extracted from the National Surgical Quality Improvement Program (NSQIP) registry from 2005 to 2015. Adult patients undergoing peripheral nerve surgery in the extremities were included. A subgroup analysis was performed for brachial plexus operations. Multivariable logistic regression was performed to identify predictors of any complication, surgical site infection, unplanned readmission, and reoperation.

Results

A total of 2,840 patients were identified; 628 were brachial plexus operations. Overall complications were 4.4% and 7.0%, respectively. Median time for occurrence of any complication was 8 days. The most common complications were wound‐related (1.7%), which occurred at a median of 15 days postoperatively. Reoperation occurred in 1.8% of all cases; most commonly for musculoskeletal repair (16.7%). Unplanned readmissions occurred in 2.3% and were most often due to wound‐related problems (24.1%). Preoperatively contaminated wounds, inpatient procedures, and longer operative time seemed to have the most influence on all adverse events. In brachial plexus pathology, insulin‐dependent diabetes and emergency cases also negatively affected outcomes.

Conclusions

Complications usually occur one to two weeks postoperatively. Preoperatively contaminated wounds, inpatient procedures, and longer operative times influence outcome. Anatomical level of operation results in significantly different lengths of hospital stay; brachial plexus pathology has the longest length of stay.

Dynamic factors involved in common peroneal nerve entrapment neuropathy

BACKGROUND

Common peroneal nerve (CPN) entrapment neuropathy (CPNEN) is the most common peripheral neuropathy of the lower extremities. The pathological mechanisms underlying CPNEN remain unclear. We sought to identify dynamic factors involved in CPNEN by directly measuring the CPN pressure during stepwise CPNEN surgery.

METHODS

We enrolled seven patients whose CPNEN improved significantly after CPN neurolysis. All suffered intermittent claudication, and the repetitive plantar flexion test, used as a CPNEN provocation test, was positive. During decompression surgery we directly measured the CPN pressure during several decompression steps.

RESULTS

Before CPN decompression, plantar flexion elicited a statistically significant increase in the CPN pressure (from 1.8 to 37.3, p < 0.05), as did plantar extension (from 1.8 to 23.1, p < 0.05). The CPN pressure gradually decreased during step-by-step surgery; it was lowest after resection of the peroneus longus muscle (PLM) fascia.

CONCLUSIONS

Dynamic factors affect idiopathic CPNEN. The CPN pressure decreased at each surgical decompression step, and removal of the PLM fascia resulted in adequate decompression of the CPN. Our findings shed light on the etiology of idiopathic CPNEN and recommend adequate CPNEN decompression procedures.

The power function of the ten test for measuring neural sensitivity in clinical pain or sensory abnormalities

This review highlights a simple psychophysical quantitative sensory testing (QST) method (the ten test) for research and clinical practice as it relates to sensitivity change and symptom improvement in pain populations. This cost-effective QST has a three-fold benefit of being diagnostic, prognostic and providing outcome evaluation. The power function of the ten test is discussed with the theoretical foundation of levels of measurement and psychophysical method that can approach ratio scaling in mind. The ratio level measurement might be useful for the researcher as the normative values of different QSTs are not well established. As a reliable and valid testing method, it provides an option for clinicians in busy clinical settings, and/or where QST equipment is unavailable.

Decompression of the superficial peroneal nerve: clinical outcomes and anatomical study

OBJECTIVE

The authors of this study sought to determine the outcomes of patients undergoing superficial peroneal nerve (SPN) release to treat lower-extremity pain and describe consistent anatomical landmarks to direct surgical planning.

METHODS

This retrospective cohort study examined 54 patients with pain in the SPN distribution who were treated with decompression between 2011 and 2014. Patients rated pain and the effect of pain on quality of life (QOL) on the visual analog scale (VAS) from 0 to 10. Scores were then converted to percentages. Linear regression analysis was performed to assess the impact of the preoperative effect of pain on QOL, age, body mass index (BMI), and preoperative duration of pain on the postoperative effect of pain on QOL. Measurements were made intraoperatively in 13 patients to determine the landmarks for identifying the SPN.

RESULTS

A higher BMI was a negative predictor for improvement in the effect of pain on QOL. A decrease in pain compared with the initial level of pain suggested a nonlinear relationship between these variables. A minority of patients (7 of 16) with a preoperative pain VAS score ≤ 60 reported less pain after surgery. A large majority (30 of 36 patients) of those with a preoperative pain VAS score > 60 reported improvement. Intraoperative measurements demonstrated that the SPN was consistently found to be 5 ± 1.1, 5 ± 1.1, and 6 ± 1.2 cm lateral to the tibia at 10, 15, and 20 cm proximal to the lateral malleolus, respectively.

CONCLUSIONS

A majority of patients with a preoperative pain VAS score > 60 showed a decrease in postoperative pain. A higher BMI was associated with less improvement in the effect of pain on QOL. This information can be useful when counseling patients on treatment options. Based on the intraoperative data, the authors found that the SPN can be located at reliable points in reference to the tibia and lateral malleolus.

Subclinical Peroneal Neuropathy: A Common, Unrecognized, and Preventable Finding Associated With a Recent History of Falling in Hospitalized Patients

PURPOSE

Identification of modifiable risk factors for falling is paramount in reducing the incidence and morbidity of falling. Peroneal neuropathy with an overt foot drop is a known risk factor for falling, but research into subclinical peroneal neuropathy (SCPN) resulting from compression at the fibular head is lacking. The purpose of our study was to determine the prevalence of SCPN in hospitalized patients and establish whether it is associated with a recent history of falling.

METHODS

We conducted a cross-sectional study of 100 medical inpatients at a large academic tertiary care hospital in St Louis, Missouri. General medical inpatients deemed at moderate to high risk for falling were enrolled in the summer of 2013. Patients were examined for findings that suggest peroneal neuropathy, fall risk, and a history of falling. Multivariate logistic regression was used to correlate SCPN with fall risk and a history of falls in the past year.

RESULTS

The mean patient age was 53 years (SD = 13 years), and 59 patients (59%) were female. Thirty-one patients had examination findings consistent with SCPN. After accounting for various confounding variables within a multivariate logistic regression model, patients with SCPN were 4.7 times (95% CI, 1.4-15.9) more likely to report having fallen 1 or more times in the past year.

CONCLUSIONS

Subclinical peroneal neuropathy is common in medical inpatients and is associated with a recent history of falling. Preventing or identifying SCPN in hospitalized patients provides an opportunity to modify activity and therapy, potentially reducing risk.

Superior Cluneal Nerve Entrapment Neuropathy and Gluteus Medius Muscle Pain: Their Effect on Very Old Patients with Low Back Pain

OBJECTIVE

In the very elderly, their general condition and poor compliance with drug regimens can render the treatment of low back pain (LBP) difficult. We report the effectiveness of a less-invasive treatment for intractable LBP from superior cluneal nerve entrapment neuropathy (SCN-EN) and gluteus medius muscle (GMeM) pain.

PATIENTS AND METHODS

Between April 2013 and March 2015, we treated 17 consecutive elders with LBP, buttock pain, and leg pain. They were 4 men and 13 women ranging in age from 85 to 91 years (mean 86.6 years). We carefully ascertained that their symptoms were attributable to SCN-EN and GMeM pain. The median follow-up period was 21.5 ± 12.2 months (range 2-35 months).

RESULTS

SCN-EN was diagnosed in 15 patients (28 sites) and GMeM pain in 14 (27 sites). In 5 patients, we obtained symptom control by local block (Numerical Rating Scale for LBP: declined from 7.8 to 0.8 [P < 0.05], Roland-Morris Disability Questionnaire score: declined from 16.5 to 5.2). The other 12 were operated under local anesthesia (SCN neurolysis, GMeM decompression). As 3 patients reported the persistence of leg pain postoperatively, they subsequently underwent peroneal nerve neurolysis and surgery for tarsal tunnel syndrome. These treatments resulted in significantly symptom abatement (Numerical Rating Scale: from 8.2 to 1.7, Roland-Morris Disability Questionnaire score: from 12.8 to 8.6; P < 0.05).

CONCLUSIONS

Even very old patients with intractable LBP, buttock pain, and leg pain due to SCN-EN or GMeM pain can be treated successfully by peripheral block and less-invasive surgery under local anesthesia.

Repetitive Plantar Flexion (Provocation) Test for the Diagnosis of Intermittent Claudication due to Peroneal Nerve Entrapment Neuropathy: Case Report

The diagnosis of peroneal nerve (PN) entrapment neuropathy (PNEN) is based on clinical symptoms and nerve conduction studies. However, these studies do not always detect PNEN. Our 64-year-old patient suffered persistent left L5 numbness after two lumbar surgeries. Two years before admission to our institute his left leg pain gradually reappeared. When walking, his numbness in the left lower thigh to the dorsum of the foot increased. Electrophysiological testing revealed no conduction block on the PN. To identify the origin of his intermittent symptoms we performed loading of repetitive ankle plantar flexion in the at-rest posture to avoid the lumbar factor. We used this provocation test to check for PNEN because it occurs at a site where the PN passes the soleus- and the peroneus longus muscle (SM, PLM). The symptoms appeared reproducibly within 10 s of loading. PN neurolysis under local anesthesia showed that the PN was strongly compressed by the SM and PLM. This procedure eased his symptoms and he was able to walk without elicitation of numbness and pain upon repetitive ankle plantar flexion. In our case, repetitive plantar flexion elicited the symptoms and this provocation test may be useful to identify PN dynamic entrapment neuropathy as the origin of intermittent claudication.

Microsurgical Decompression for Peroneal Nerve Entrapment Neuropathy

Peroneal nerve entrapment neuropathy (PNEN) is one cause of numbness and pain in the lateral lower thigh and instep, and of motor weakness of the extensors of the toes and ankle. We report a less invasive surgical procedure performed under local anesthesia to treat PNEN and our preliminary outcomes. We treated 22 patients (33 legs), 7 men and 15 women, whose average age was 66 years. The mean postoperative follow-up period was 40 months. All patients complained of pain or paresthesia of the lateral aspect of affected lower thigh and instep; all manifested a Tinel-like sign at the entrapment point. As all had undergone unsuccessful conservative treatment, we performed microsurgical decompression under local anesthesia. Of 19 patients who had undergone lumbar spinal surgery (LSS), 9 suffered residual symptoms attributable to PNEN. While complete symptom abatement was obtained in the other 10 they later developed PNEN-induced new symptoms. Motor weakness of the extensors of the toes and ankle [manual muscle testing (MMT) 4/5] was observed preoperatively in 8 patients; it was relieved by microsurgical decompression. Based on self-assessments, all 22 patients were satisfied with the results of surgery. PNEN should be considered as a possible differential diagnosis in patients with L5 neuropathy due to lumbar degenerative disease, and as a causative factor of residual symptoms after LSS. PNEN can be successfully addressed by less-invasive surgery performed under local anesthesia.

A Unique Case of Common Peroneal Nerve Entrapment

The authors present a case of a previously healthy 36-year-old man with a 3-day history of spontaneous complete right lower extremity foot drop. He noticed the symptoms immediately when he attempted to stand after waking from sleep. The patient had no history of similar symptoms, recent trauma, or peripheral nerve disease. Physical examination showed a slap foot gait, complete numbness of the lateral leg and dorsal foot, and 0/5 strength with ankle and great toe dorsiflexion and ankle eversion. Serum laboratory studies showed normal values. Nerve conduction studies confirmed increased latency and decreased amplitude of the right peroneal nerve at the knee, whereas electromyography showed denervation of the tibialis anterior and extensor digitorum brevis. Anteroposterior and lateral radiographs showed a normal right knee with the exception of a posterior fibular neck exostosis. Physical therapy, an ankle-foot orthosis, and a 5-day course of oral prednisone burst (50 mg) were prescribed. After 1 month of therapy without resolution, the patient underwent surgical release of the common peroneal nerve and excision of the bony prominence. Twelve days postoperatively, the patient had no sensory improvements but had improved findings on motor examination. Three months postoperatively, the patient had near-normal sensation to light touch in the superficial and deep peroneal nerves, with 5/5 strength and a normal gait. The patient returned to all activity without limitations. The authors present this unique case describing a fibro-osseous source of common peroneal compressive neuropathy and review the literature for spontaneous peroneal entrapment, highlighting the importance of prompt diagnosis and treatment.

Determinants of nerve conduction recovery after nerve injuries: Compression duration and nerve fiber types

INTRODUCTION

The aims of this study were to determine the influences of: (1) timing of nerve decompression; and (2) nerve fiber types on the patterns of nerve conduction studies (NCS) after nerve injury.

METHODS

Nerve conduction studies (NCS) were performed on 3 models of nerve injury: (1) crush injury due to transient nerve compression (crush group); (2) chronic constriction injury (CCI), or permanent compression (CCI group); and (3) CCI with removal of ligatures, or delayed nerve decompression (De-CCI group).

RESULTS

There were distinct patterns of NCS recovery. The crush and De-CCI groups achieved similar motor nerve recovery, better than that of the CCI group. In contrast, recovery of sensory nerves was limited in the CCI and De-CCI groups and was lower than in the crush group.

CONCLUSIONS

Immediate relief of compression resulted in the best recovery of motor and sensory nerve conduction. In contrast, delayed decompression restored only motor nerve conduction.

Sciatic nerve compression by neurogenic heterotopic ossification: use of CT to determine surgical indications

OBJECTIVE

To describe the characteristics of neurogenic heterotopic ossification (NHO) based on clinical tests, electroneuromyography (ENMG) and CT in a database of patients with lesions of the central nervous system who required sciatic nerve neurolysis along with posterior hip NHO resection, and to determine the respective roles of ENMG and CT in the management of posterior hip NHOs in patients who are unable to communicate or express pain.

METHODS

The consistency of the ENMG results with clinical findings, CT results and macroscopic signs of lesions was retrospectively assessed after sciatic nerve neurolysis and ablation of 55 posterior hip NHOs.

RESULTS

Sciatic nerve neurolysis was necessary in 55 cases (47.4%; 55 out of 116). CT showed contact of the NHO with the nerve in all cases: 5 in contact with no deflection, 3 in contact with deflection, 21 moulded into a gutter and 26 entrapped in the NHO. There were clinical signs of sciatic nerve lesion in 21.8% of cases (12 out of 55). ENMG showed signs of sciatic nerve lesions in only 55.6% (10 out of 18), only 4 of whom presented with clinical signs of a nerve lesion. No significant relationship was found between clinical symptoms and ENMG findings of sciatic nerve compression (n = 13, p = 0.77).

CONCLUSION

Nerve compression by NHO is likely an underdiagnosed condition, particularly in patients who are unable to communicate. Diagnosis of sciatic compression by NHO should be based on regular clinical examinations and CT. ENMG is not sufficiently sensitive to be used alone for surgical decision-making.

Multiple locations of nerve compression: an unusual cause of persistent lower limb paresthesia

A paucity of appreciation exists that the "double crush" phenomenon can account for persistent leg symptoms even after spinal neural decompression surgery. We present an unusual case of multiple locations of nerve compression causing persistent lower limb paresthesia in a 40-year old male patient. The patient's lower limb paresthesia was persistent after an initial spinal surgery to treat spinal lateral recess stenosis thought to be responsible for the symptoms. It was later discovered that he had peroneal muscle herniations that had caused superficial peroneal nerve entrapments at 2 separate locations. The patient obtained much symptomatic relief after decompression of the peripheral nerve. The "double crush" phenomenon and multiple levels of nerve compression should be considered when evaluating lower limb neurogenic symptoms, especially after spinal nerve root surgery.

Clinical characteristics of peroneal nerve palsy by posture

Objective

Posture induced common peroneal nerve (CPN) palsy is usually produced during the prolonged squatting or habitual leg crossing while seated, especially in Asian culture and is manifested by the onset of foot drop. Because of its similarity to discogenic foot drop, patients may be diagnosed with a lumbar disc disorder, and in some patients, surgeons may perform unnecessary examinations and even spine surgery. The purpose of our study is to establish the clinical characteristics and diagnostic assessment of posture induced CPN palsy.

Methods

From June 2008 to June 2012, a retrospective study was performed on 26 patients diagnosed with peroneal nerve palsy in neurophysiologic study among patients experiencing foot drop after maintaining a certain posture for a long time.

Results

The inducing postures were squatting (14 patients), sitting cross-legged (6 patients), lying down (4 patients), walking and driving. The mean prolonged neural injury time was 124.2 minutes. The most common clinical presentation was foot drop and the most affected sensory area was dorsum of the foot with tingling sensation (14 patients), numbness (8 patients), and burning sensation (4 patients). The clinical improvement began after a mean 6 weeks, which is not related to neural injury times. Electrophysiology evaluation was performed after 2 weeks later and showed delayed CPN nerve conduction study (NCS) in 24 patients and deep peroneal nerve in 2 patients.

Conclusion

We suggest that an awareness of these clinical characteristics and diagnostic assessment methods may help clinicians make a diagnosis of posture induced CPN palsy and preclude unnecessary studies or inappropriate treatment in foot drop patients.

Axon counts of potential nerve transfer donors for peroneal nerve reconstruction

BACKGROUND

The common peroneal nerve is the most commonly injured nerve in the lower limb. Nerve transfer using expendable donor nerves is emerging in the literature as an alternative surgical procedure to traditional treatments.

OBJECTIVE

To identify potential donors of motor axons from the tibial nerve that can be transferred to the common peroneal nerve branches.

METHODS

Using 10 human cadaveric lower extremities, all motor nerve branches of the tibial nerve were identified and biopsied. These were compared with the motor branches to tibialis anterior and extensor hallucis longus (branches of the deep peroneal nerve).

RESULTS

The most suitable donor nerves with respect to cross-sectional area to tibialis anterior (cross sectional area [mean ± SD] 0.255±0.111 mm) was the motor branch to lateral gastrocnemius (0.256±0.105 mm). When comparing the total number of axons, the branch to the tibialis anterior had a mean of 3363±1997 axons. The branch to the popliteus was most similar, with 3317±1467 axons. The most suitable donor nerves for the motor branch to extensor hallucis longus (cross sectional area 0.197±0.302 mm) with respect to cross-sectional area was the motor branch to flexor hallucis longus (0.234±0.147 mm). When comparing the total number of axons, the branch to the extensor hallucis longus had an average of 2062±2314 axons. The branch to the lateral gastrocnemius was most similar with 2352±1249 axons and was a suitable donor.

CONCLUSION

Nerve transfers should be included in the armamentarium for lower extremity reinnervation, as it is in the upper limb.

Compression and entrapment neuropathies

Peripheral nerve entrapments are frequent. They usually appear in anatomical tunnels such as the carpal tunnel. Nerve compressions may be due to external pressure such as the fibular nerve at the fibular head. Malignant or benign tumors may also damage the nerve. For each nerve from the upper and lower limbs, detailed clinical, electrophysiological, imaging, and therapeutic aspects are described. In the upper limbs, carpal tunnel syndrome and ulnar neuropathy at the elbow are the most frequent manifestations; the radial nerve is less frequently involved. Other nerves may occasionally be damaged and these are described also. In the lower limbs, the fibular nerve is most frequently involved, usually at the fibular head by external compression. Other nerves may also be involved and are therefore described. The clinical and electrophysiological examination are very important for the diagnosis, but imaging is also of great use. Treatments available for each nerve disease are discussed.

Fate of stem cell transplants in peripheral nerves

While damaged peripheral nerves demonstrate some potential to regenerate, complete functional recovery remains infrequent, owing to a functional loss of supportive Schwann cells distal to the injury. An emerging solution to improve upon this intrinsic regenerative capacity is to supplement injured nerves with stem cells derived from various tissues. While many of these strategies have proven successful in animal models, few studies have examined the behavior of transplanted stem cells in vivo, including whether they survive and differentiate. In previous work, we demonstrated that cells derived from neonatal rodent dermis (skin-derived precursor cells, or SKPs) could improve regenerative parameters when transplanted distal to both acute and chronic nerve injuries in Lewis rats. The aim of this work was to track the fate of these cells in various nerve injury paradigms and determine the response of these cells to a known glial growth factor. Here, we report that SKPs survive, respond to local cues, differentiate into myelinating Schwann cells, and avoid complete clearance by the host's immune defenses for a minimum of 10weeks. Moreover, the ultimate fate of SKPs in vivo depends on the nerve environment into which they are injected and can be modified by inclusion of heregulin-1β.

Peripheral nerve entrapments of the lower leg, ankle, and foot

Peripheral nerve entrapments are a relatively rare and heterogeneous group of nerve disorders encompassing a wide variety of etiologies and clinical presentations. These conditions can present significant diagnostic challenges, owing to both the variety of symptoms these patients display, along with the anatomic variation that exists between individuals. Precise knowledge of the anatomic course, the common motor and sensory distributions of each of the peripheral nerves, and judicious use of imaging or electrodiagnostic testing can greatly assist in arriving at a correct diagnosis. In this article, we discuss in detail the anatomy, clinical presentation, diagnosis, and treatment options for peripheral nerve entrapments of the lower extremity involving the sural, saphenous and common, superficial, and deep peroneal nerves.

The 'Ten Test': application and limitations in assessing sensory function in the paediatric hand

BACKGROUND

The Ten Test, first described in 1997 by Strauch et al., is a simple, rapid, reliable and sensitive method to evaluate hand sensibility in adults. In this study, we validated its use in children.

METHODS

We asked patients to rate sensibility elicited by a light moving touch on the palmar surface of digits in reference to sensibility elicited by the same touch in a digit confirmed as normal.

RESULTS

A total of 73 subjects (age range: 1-12 years) were tested. Patients under age 5 years were significantly less likely to complete the test. The kappa statistic for the Ten Test in nine subjects, each tested separately by two examiners, demonstrated very strong inter-observer reliability (kappa=1.0, p<0.003).

CONCLUSIONS

The Ten Test is a simple, validated, non-threatening method to evaluate hand sensibility in children and adolescents. We recommend its clinical use in patients age 5 years and older.

[The main tunnel syndromes]

Several tunnel syndromes are responsible for substantial functional impairment. The diagnosis has to be made and treatment is most often very simple--nerve decompression--with excellent results. Of these syndromes, the most common are median and ulnar tunnel syndromes of the wrist and ulnar tunnel syndrome of the elbow, but other syndromes must be identified at the risk of therapy failure due to poorly adapted treatment. Finally, good knowledge of this pathology must lead to prevention of the iatrogenic forms (sequelae of inguinal hernia treatment, ileac crest graft harvesting) by educating all surgeons interested in peripheral nerve surgery.

Practical considerations concerning the use of stem cells for peripheral nerve repair

In this review the authors intend to demonstrate the need for supplementing conventional repair of the injured nerve with alternative therapies, namely transplantation of stem or progenitor cells. Although peripheral nerves do exhibit the potential to regenerate axons and reinnervate the end organ, outcome following severe nerve injury, even after repair, remains relatively poor. This is likely because of the extensive injury zone that prevents axon outgrowth. Even if outgrowth does occur, a relatively slow growth rate of regeneration results in prolonged denervation of the distal nerve. Whereas denervated Schwann cells (SCs) are key players in the early regenerative success of peripheral nerves, protracted loss of axonal contact renders Schwann cells unreceptive for axonal regeneration. Given that denervated Schwann cells appear to become effete, one logical approach is to support the distal denervated nerve environment by replacing host cells with those derived exogenously. A number of different sources of stem/precursor cells are being explored for their potential application in the scenario of peripheral nerve injury. The most promising candidate, transplant cells are derived from easily accessible sources such as the skin, bone marrow, or adipose tissue, all of which have demonstrated the capacity to differentiate into Schwann cell-like cells. Although recent studies have shown that stem cells can act as promising and beneficial adjuncts to nerve repair, considerable optimization of these therapies will be required for their potential to be realized in a clinical setting. The authors investigate the relevance of the delivery method (both the number and differentiation state of cells) on experimental outcomes, and seek to clarify whether stem cells must survive and differentiate in the injured nerve to convey a therapeutic effect. As our laboratory uses skin-derived precursor cells (SKPCs) in various nerve injury paradigms, we relate our findings on cell fate to other published studies to demonstrate the need to quantify stem cell survival and differentiation for future studies.