Functional outcomes of different surgical treatments for common peroneal nerve injuries: a retrospective comparative study.

BACKGROUND: This study aims to assess the recovery patterns and factors influencing outcomes in patients with common peroneal nerve (CPN) injury. METHODS: This retrospective study included 45 patients with CPN injuries treated between 2009 and 2019 in Jing'an District Central Hospital. The surgical interventions were categorized into three groups: neurolysis (group A; n = 34 patients), nerve repair (group B; n = 5 patients) and tendon transfer (group C; n = 6 patients). Preoperative and postoperative sensorimotor functions were evaluated using the British Medical Research Council grading system. The outcome of measures included the numeric rating scale, walking ability, numbness and satisfaction. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal time interval between injury and surgery for predicting postoperative foot dorsiflexion function, toe dorsiflexion function, and sensory function. RESULTS: Surgical interventions led to improvements in foot dorsiflexion strength in all patient groups, enabling most to regain independent walking ability. Group A (underwent neurolysis) had significant sensory function restoration (P < 0.001), and three patients in Group B (underwent nerve repair) had sensory improvements. ROC analysis revealed that the optimal time interval for achieving M3 foot dorsiflexion recovery was 9.5 months, with an area under the curve (AUC) of 0.871 (95% CI = 0.661-1.000, P = 0.040). For M4 foot dorsiflexion recovery, the optimal cut-off was 5.5 months, with an AUC of 0.785 (95% CI = 0.575-0.995, P = 0.020). When using M3 toe dorsiflexion recovery or S4 sensory function recovery as the gold standard, the optimal cut-off remained at 5.5 months, with AUCs of 0.768 (95% CI = 0.582-0.953, P = 0.025) and 0.853 (95% CI = 0.693-1.000, P = 0.001), respectively. CONCLUSIONS: Our study highlights the importance of early surgical intervention in CPN injury recovery, with optimal outcomes achieved when surgery is performed within 5.5 to 9.5 months post-injury. These findings provide guidance for clinicians in tailoring treatment plans to the specific characteristics and requirements of CPN injury patients.

Common fibular nerve palsy due to the Fabella: A review.

One of the most common nerve palsies - common fibular nerve palsy - can be caused by the variant small sesamoid bone in the posterolateral compartment of the knee joint known as the fabella. We compared and reviewed all reported cases of common fibular nerve palsy due to fabellae in the English literature. Compression can develop spontaneously or post-surgically (total knee arthroplasty). Symptoms progress rapidly to complete foot drop. Among all the cases reviewed, 68.42% were males with a median age of 39.39 years. Fabella compression was more common in the left common fibular nerve (CFN) (63.16%). Both big (23 × 20 × 16 mm) and small (5 × 5 mm) fabellae can be responsible for compression. While diagnosis can be problematic, the treatment (either surgical fabellectomy or conservative) is relatively easy and brings quick improvement.

Differential Diagnosis of "Foot Drop": Implications for Peripheral Nerve Surgery.

BACKGROUND: At least 128,000 patients in the United States each year suffer from foot drop. This is a debilitating condition, marked by the inability to dorsiflex and/or evert the affected ankle. Such patients are rendered to a lifetime of relying on an ankle-foot orthosis (AFO) for walking and nighttime to prevent an equinovarus contracture. METHODS: This narrative review explores the differential diagnosis of foot drop, with a particular focus on clinical presentation and recovery, whether spontaneously or through surgery. RESULTS: Contrary to popular belief, foot drop can be caused by more than just insult to the common peroneal nerve at the fibular head (fibular tunnel). It is a common endpoint for a diverse spectrum of nerve injuries, which may explain its relatively high prevalence. From proximal to distal, these conditions include lumbar spine nerve root damage, sciatic nerve palsy at the sciatic notch, and common peroneal nerve injury at the fibular head. Each nerve condition is marked by a unique clinical presentation, frequency, likelihood for spontaneous recovery, and cadre of peripheral nerve techniques. CONCLUSION: The ideal surgical technique for treating foot drop, other than neurolysis for compression, remains elusive as traditional peripheral nerve procedures have been marred by a wide spectrum of functional results. Based on a careful understanding of why past techniques have achieved limited success, we can formulate a working set of principles to help guide surgical innovation moving forward, such as fascicular nerve transfer.

Giant Common Peroneal Nerve Schwannoma Mimicking Synovial Sarcoma: An Unusual Case Report.

Schwannoma, also known as neurilemmoma or Schwann cell tumor, is one of the most common neoplasms of the nerve sheath which usually appears at the head, neck, or upper extremity. Schwannoma occurrence in the lower extremity originating from the common peroneal nerve is rarely reported according to literary findings. We report a case of a 32-year-old man who presented with a 6-month history of a growing lump in the left knee. MRT revealed a well-defined 9.6 cm × 7.8 cm × 6.5 cm multilobular mass of heterogeneous consistency with areas of necroses with a likely diagnosis of synovial sarcoma. After surgery, a final histopathological assessment of the tumor demonstrated Antoni A and B patterns with nuclear palisading, hallmarks of a schwannoma. Postoperatively the patient suffered a neurological complication-impaired dorsiflexion of the left foot. The patient started immediate physiotherapy in the Department of Rehabilitation. Three weeks after the operation, gradual improvement in neurological function was observed. To date, complete tumor excision combined with microscopic analysis and immunohistochemical staining remains the gold standard in diagnosing and treating a peripheral nerve schwannoma. Moreover, the use of additional nerve monitoring tools during surgery could help to prevent complications.

Can MR neurography of the common peroneal nerve predict a residual motor deficit in patients with foot drop?

OBJECTIVE: To determine if MR neurography of the common peroneal nerve (CPN) predicts a residual motor deficit at 12-month clinical follow-up in patients presenting with foot drop. MATERIALS AND METHODS: A retrospective search for MR neurography cases evaluating the CPN at the knee was performed. Patients were included if they had electrodiagnostic testing (EDX) within 3 months of imaging, ankle and/or forefoot dorsiflexion weakness at presentation, and at least 12-month follow-up. Two radiologists individually evaluated nerve size (enlarged/normal), nerve signal (T2 hyperintense/normal), muscle signal (T2 hyperintense/normal), muscle bulk (normal/Goutallier 1/Goutallier > 1), and nerve and muscle enhancement. Discrepancies were resolved via consensus review. Multivariable logistical regression was used to evaluate for association between each imaging finding and a residual motor deficit at 12-month follow-up. RESULTS: Twenty-three 3 T MRIs in 22 patients (1 bilateral, mean age 52 years, 16 male) met inclusion criteria. Eighteen cases demonstrated common peroneal neuropathy on EDX, and median duration of symptoms was 5 months. Six cases demonstrated a residual motor deficit at 12-month follow-up. Fourteen cases underwent CPN decompression (1 bilateral) within 1 year of presentation. Three cases demonstrated Goutallier > 1 anterior compartment muscle bulk. Multivariable logistical regression did not show a statistically significant association between any of the imaging findings and a residual motor deficit at 12-month follow-up. CONCLUSION: MR neurography did not predict a residual motor deficit at 12-month follow-up in patients presenting with foot drop, though few patients demonstrated muscle atrophy in this study.

Analysis of outcome reporting in common peroneal neuropathy studies: a systematic review of the literature.

BACKGROUND: There is a strong need for the development of core outcome sets (COS) across nerve surgery to allow for improved data synthesis, meta-analyses, and reporting consistency. Development of a core outcome set typically starts with assessing the literature for previously reported outcome measures. Common peroneal neuropathy (CPN) is the most common compressive mononeuropathy of the lower extremity and can result in pain, motor, and sensory deficits. A COS for COmmon PEroneal neuropathy (COS-COPE) is needed to improve future study design and comparison and synthesis of data. The goal of the current study was to assess the literature for outcomes reported in studies on CPN as the first step in the development of a COS. METHODS: A systematic review of the literature from 2000 to 2023 was performed utilizing PubMed and Medical Subject Headings (MeSH). Identified articles were screened according to study inclusion/exclusion criteria. Outcome measures reported in each included study were recorded and categorized into motor, sensory, pain, composite foot/ankle score, electrodiagnostics, function/disability patient-reported outcome (PRO), psychological, or other outcomes. Descriptive statistics were performed. RESULTS: A total of 31 articles met criteria for inclusion. A motor outcome was reported in 26 (83.9%) studies; 12 (38.7%) reported a sensory outcome; 8 (25.8%) reported a pain outcome; 4 (12.9%) reported a composite foot/ankle score; 3 (9.7%) reported electrodiagnostics; 1 (3.2%) reported a function/disability PRO; 1 (3.2%) reported a psychological outcome; 2 (6.5%) reported an imaging outcome; 3 (9.7%) reported other outcomes. Across the studies, 29 distinct outcome measures were reported. CONCLUSIONS: The outcomes reported in studies on CPN are varied and inconsistent. It is likely that a combination of motor, sensory, pain, and functional outcomes will be needed in a COS to best study CPN. These data will serve as a baseline for the ultimate development of the COS-COPE.

Partial tibial nerve transfer for iatrogenic peroneal nerve palsy after endovenous laser ablation for varicose veins of the lower extremity: A case report.

Postprocedural peroneal nerve palsy after endovenous laser ablation (EVLA) for varicose veins is rare and is associated with poor functional recovery. There have been no reports using tibial nerve transfer for iatrogenic peroneal nerve palsy after EVLA. Herein, we present a case with peroneal nerve injury after EVLA, which was successfully treated by partial tibial nerve transfer for the first time. A 75-year-old female presented with a right foot drop immediately after EVLA of the lesser saphenous vein. The ankle and toe dorsiflexion had a muscle grade of M0 on the British Medical Research Council muscle scale, without voluntary motor unit action potentials (MUAP) in the tibialis anterior (TA) muscle on the needle electromyography. Three months after the injury, surgical nerve exploration revealed a damaged common peroneal nerve with discoloration and scarring at the fibular head. Intraoperative deep peroneal nerve stimulation confirmed the absence of compound muscle action potentials in the TA. The best functioning motor fascicles of the tibial nerve were transferred to the deep peroneal main trunk involving motor branches of the TA, extensor digitorum longus, and extensor hallucis longus (EHL) through the interosseous membrane. The postoperative course was uneventful, with no complications. After 3 months of surgery, nascent MUAP appeared in the TA. After 24 months, the patient regained the TA and EHL muscle function and ambulation without an ankle-foot orthosis and tibial nerve deficits. Thus, our procedure may serve as an alternative to nerve grafting, tendon transfer, and orthoses for better management of the major neural complications associated with EVLA.

Tendon transfer in foot drop: a systematic review.

INTRODUCTION: Foot drop is a disorder that impairs walking and leads to tripping and falling. Tendon transfer (e.g., tibialis posterior tendon) is a typical secondary procedure in foot drop treatment. The purpose of this systematic review was to identify the most common tendon transfer techniques for treating foot drop and to analyze the reported functional outcomes. Furthermore, it was of interest if the type of surgical technique affects the functional outcome. METHODS: A PubMed and MEDLINE literature search was performed according to PRISMA guidelines. The search terms used were ("tendon transfer" OR "tendon transposition") AND ("foot drop" OR "peroneal neuropathies"). Any study published before January 2020 was considered for inclusion. No case reports or reviews were included. Common outcome measures (Stanmore score, AOFAS, FAAM, AFO use, patient satisfaction and active ankle dorsiflexion) were evaluated. The quality of the included studies was assessed using the Coleman Methodology Score. RESULTS: Of the 125 reviewed publications, 37 met the inclusion criteria. 42 cohorts were analyzed. The frequently reported tendon transfer technique was the tibialis posterior tendon transfer through the interosseus membrane. The most used fixation technique was tendon on tendon fixation; however in recent years, a tendon to bone fixation has gained popularity. There was an increase in Stanmore scores and AOFAS postoperatively and a decrease of AFO use postoperatively observed. CONCLUSIONS: Due to various outcome measures and lack of preoperative assessment in the included studies, a meta-analysis of the pooled results was not possible. Nevertheless, the findings of this study show that tendon transfer increases mobility and self-independency leading to patient satisfaction. The choice of the surgical technique does not affect the outcome. A prospective collection of patient data and standardized outcome measures will be important to further analyze the efficacy of tendon transfer techniques.

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.

Comparison of Isolated Sciatic Nerve and Sacral Nerve Root Endometriosis: A Review of the Literature.

OBJECTIVE: This review aimed to compare isolated sciatic and sacral nerve root endometriosis in terms of anatomic distribution, patients' symptoms and history, diagnostics, treatments, and outcomes. DATA SOURCE: We searched PubMed, MEDLINE, Web of Science, and Embase from inception to October 2021 using a combination of keywords including "sciatic nerve endometriosis," "sacral nerve root endometriosis," and associated Medical Subject Headings. Relevant publications and references were also checked for further articles. METHODS OF STUDY SELECTION: Two independent researchers performed the study selection. We included all original research articles, case reports, and case series in English that reported on the isolated sciatic nerve and sacral nerve root endometriosis. TABULATION, INTEGRATION, AND RESULTS: The initial search identified 92 articles, and 40 articles, mostly case reports and case series, were included. The review included 362 patients: with 256 and 106 patients in the sacral and the sciatic groups, respectively. In both groups, most patients had right-sided endometriosis. In the sciatic group, most of the patients presented with foot drop, leg motor weakness, and sciatic dermatome hypoesthesia. The frequencies of all these symptoms were significantly higher in the sciatic group (all p <.001). By contrast, in the sacral group, most of patients presented with pudendal neuralgia (p <.001). Intraoperative, early, late, and 1-year postoperative complications did not differ significantly between the 2 groups. CONCLUSION: This study indicated that isolated sciatic and sacral nerve root endometrioses were more common on the right side. Laparoscopic surgery was more commonly performed over traditional open or transgluteal surgery techniques. Sacral nerve root endometriosis is often accompanied by deep infiltrating endometriosis. Magnetic resonance imaging and myelography may be useful diagnostic tools in the preoperative workup. There was usually no significant improvement after surgery in cases of isolated sciatic nerve endometriosis presenting with foot drop.

Chiari malformation type 1 presenting as isolated unilateral foot drop with rapid recovery following posterior fossa decompression.

BACKGROUND: Chiari malformation (CM) type 1 is characterized by descent of the cerebellar tonsils resulting from crowding of the posterior fossa. In 30% of cases, it is associated with syringomyelia. When symptomatic, it may result in a classic constellation of symptoms. CASE PRESENTATION: Here we describe a case of a 16-year-old male who presented with isolated, unilateral foot drop due to CM type 1 and holosyrinx. This unique presentation is extremely rare, and we additionally present a review of all other reported cases in the literature. After undergoing posterior fossa decompression with C1 laminectomy and duraplasty, our patient made a complete neurological recovery within 2 weeks postoperatively and his MRI entire spine at 3 months postoperatively demonstrated a nearly complete resolution of the holosyrinx with significant decompression of the foramen magnum. CONCLUSION: This rare presentation highlights the importance of maintaining a broad differential, particularly in pediatric patients, and expediting the workup in order to offer a surgical decompression within 1-2 months of foot weakness to maximize the probability of a full neurological recovery.

Surgical decompression timing for patients with foot drop from lumbar degenerative diseases: a meta-analysis.

OBJECTIVE: To compare the outcomes of early (within 1 month after foot drop) decompression versus late (1 month or more after foot drop) decompression in order to determine the optimal surgical intervention timing for lumbar degenerative diseases. METHODS: The MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science and SCOPUS electronic databases were searched for relevant articles published until May 2021 were conducted. Cochrane Collaboration guidelines were used for data extraction and quality assessment. Outcomes of interest were manual muscle testing (MMT) and recovery rate (MMT ≥ 4) for foot drop in lumbar degenerative diseases. RESULTS: Six clinical studies were retrieved, including 312 randomized participants. One hundred fifty-seven patients underwent early decompression surgery, and 155 underwent late decompression surgery. There were significant differences between the two groups in recovery rate (95% confidence interval [CI] 1.59, 2.57) and neurological improvement (95% confidence interval [CI] 0.21, 1.66). Early surgical decompression provided better recovery rate and neurological improvement for foot drop in lumbar degenerative diseases than late surgical decompression. CONCLUSION: Early surgical decompression within was beneficial in terms of recovery rate and neurological improvement compared with late surgery. Early surgical decompression (within 1 month) is recommended for patients with foot drop in lumbar degenerative diseases.

Foot drop as the initial symptom caused by thoracic disc herniation.

BACKGROUND: Foot drop is a syndrome resulting from weakness or paralysis of the tibialis anterior muscle. Some patients with thoracic disc herniation seek medical help complain of foot drop as the initial symptom. The study investigated the clinical characteristics of these patients and clarified the clinical efficacy after treatment. METHODS: A total of 13 patients with foot drop as the initial symptom arising from thoracic disc herniation were collected from January 2015 to December 2020. The average follow-up period was 20.5 months. We recorded neurological functions, the tibialis anterior muscle strength, Japanese Orthopedic Association score (JOA), location of the lesion, and occupation rate of herniation in the spinal canal preoperatively and at the final follow-up. RESULTS: None pathological reflex was found in the patients. Surgical treatment was performed in 12 of the 13 patients, and tibialis anterior functional recovery was observed in 83.4% (10/12) of the cases, with an average recovery rate of 52.8 ± 18.5%. The mean JOA score increased from 6.8 ± 1.9 points preoperatively to 8.9 ± 1.3 points postoperatively (p < 0.05), achieving a mean recovery rate of 52.3 ± 13.1%. The MRI showed the conus medullaris was obviously compressed at the level of T11-L1, and the occupation rate of herniation was more than 40% in all patients, with an average of 65.4 ± 16.3%. CT indicated that 84.6% of the cases had calcification in intervertebral discs. CONCLUSION: Foot drop can be the initial symptom caused by thoracic disc herniation at the T11-L1 level, especially for the calcified disc herniation. A satisfactory recovery rate can be achieved by surgical decompression with fixation.

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.

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.

Soft Tissue Management and Tibialis Posterior Tendon Transfer in Acute Correction for Neglected Drop Foot Deformity.

Acute correction of rigid drop foot deformity can be problematic due to the skin defect that may occur in the medial part of the ankle. The purpose of this study is to present an innovative solution for this problem. We hypothesized that acute correction for rigid ankle contractures without arthrosis might be possible if the medial skin defect could be closed. Therefore, we described a surgical technique for acute functional correction of rigid drop foot deformities. The closure of the medial defect was performed by applying a flap and partial-thickness skin graft. We have retrospectively evaluated the results of 18 patients who were treated between 2010 and 2016 with this technique. The mean age of the patients was 37 ± 9.5 (22-56) years. Foot drop etiology was firearm-related nerve injury. Corrections were performed after 14.6 ± 7.9 (8-38) months following the injury. At the end of an average follow-up period of 44.4 ± 6.2 (37-60) months, 14 of 18 patients (78%) recovered without complications, 3 patients experienced partial loss in the medial skin graft region, and 1 patient developed a superficial infection. None of the patients have developed pes planus. We observed that the ankle flexion contracture, which was 34° ± 9.2° (20°-50°) preoperatively, could reach an average of 2.2° ± 2.5° (0°-6°) dorsiflexion after surgery. We suggest that acute correction and tibialis posterior tendon transfer in the treatment of rigid foot drop deformity can be performed with an effective skin closure with low soft tissue complications.

Resection of Hibernoma of the Proximal Shin Followed by Foot Drop and Tendon Transfer: A Case Report.

This is the description of the case of a 42-year-old male who presented with a growing, painless lump on his anterior leg. The diagnosis of a rare tumor called hibernoma was suspected after inspection of the radiologic findings. The unusual location of the tumor resulted in superficial peroneal nerve entrapment. The tumor was excised and the diagnosis of hibernoma was confirmed by histopathology. Surgery resulted in foot drop that was successfully treated with a tibialis posterior tendon transfer. Our case illustrates a rare tumor in an unusual location that can be challenging for clinicians to discern and to properly treat.

Development of a New Ankle Joint Hybrid Assistive Limb.

Foot and ankle disabilities (foot drop) due to common peroneal nerve palsy and stroke negatively affect patients' ambulation and activities of daily living. We developed a novel robotics ankle hybrid assistive limb (HAL) for patients with foot drop due to common peroneal nerve palsy or stroke. The ankle HAL is a wearable exoskeleton-type robot that is used to train plantar and dorsiflexion and for voluntary assistive training of the ankle joint of patients with palsy using an actuator, which is placed on the lateral side of the ankle joint and detects bioelectrical signals from the tibialis anterior (TA) and gastrocnemius muscles. Voluntary ankle dorsiflexion training using the new ankle HAL was implemented in a patient with foot drop due to peroneal nerve palsy after lumbar surgery. The time required for ankle HAL training (from wearing to the end of training) was approximately 30 min per session. The muscle activities of the TA on the right were lower than those on the left before and after ankle HAL training. The electromyographic wave of muscle activities of the TA on the right was slightly clearer than that before ankle HAL training in the resting position immediately after ankle dorsiflexion. Voluntary ankle dorsiflexion training using the novel robotics ankle HAL was safe and had no adverse effect in a patient with foot drop due to peroneal nerve palsy.

Ganglion Cysts of the Proximal Tibiofibular Joint: Low Risk of Recurrence After Total Cyst Excision.

BACKGROUND: Peroneal nerve neuropathy due to compression from tumors or tumor-like lesions such as ganglion cysts is rare. Few case series have been published and reported local recurrence rates are high, while secondary procedures are frequently employed. QUESTIONS/PURPOSES: (1) What are the demographics of patients with ganglion cysts of the proximal tibiofibular joint, and what proportion of them present with intraneural cysts and peroneal nerve palsy? (2) What Musculoskeletal Tumor Society (MSTS) scores do patients with this condition achieve after decompression surgery with removal of the ganglion cyst, but no arthrodesis of the tibiofibular joint? (3) What proportion of patients experience local recurrence after surgery? METHODS: Between 2009 to 2018, 30 patients (29 primary cases) were treated for chronic peroneal palsy or neuropathy due to ganglion cysts of the proximal tibiofibular joint at two tertiary orthopaedic medical centers with total resection of the cystic lesion. MRI with contrast and electromyography (EMG) were performed preoperatively in all patients. The minimum follow-up for this series was 1 year (median 48 months, range 13 to 120); 14% (4 of 29) were lost to follow-up before that time. The MSTS score was recorded preoperatively, at 6 weeks postoperatively, and at most-recent follow-up. RESULTS: A total of 90% of the patients were male (26 of 29 patients) and the median age was 67 years (range 20 to 76). In all, 17% (5 of 29) were treated due to intraneural ganglia. Twenty-eight percent (8 of 29) presented with complete peroneal palsy (foot drop). The mean MSTS score improved from 67 ± 12% before surgery to 89 ± 12% at 6 weeks postoperative (p < 0.001) and to 92 ± 9% at final follow up (p = 0.003, comparison with 6 weeks postop). All patients improved their scores. A total of 8% (2 of 25 patients) experienced local recurrence after surgery. CONCLUSION: Ganglion cysts of the proximal tibiofibular joint occurred more often as extraneural lesions in older male patients in this small series. Total excision was associated with improved functional outcome and low risk of neurologic damage and local recurrence, and we did not use any more complex reconstructive procedures. Tendon transfers may be performed simultaneously in older patients to stabilize the ankle joint, while younger patients may recover after decompression alone, although larger randomized studies are needed to confirm our preliminary observations. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Acute bilateral foot drop with or without cauda equina syndrome-a case series.

INTRODUCTION: Isolated acute bilateral foot drop due to degenerative spine disease is an extremely rare neurosurgical presentation, whilst the literature is rich with accounts of chronic bilateral foot drop occurring as a sequela of systemic illnesses. We present, to our knowledge, the largest case series of acute bilateral foot drop, with trauma and relevant systemic illness excluded. METHODS: Data from three different centres had been collected at the time of historic treatment, and records were subsequently reviewed retrospectively, documenting the clinical presentation, radiological level of compression, timing of surgery, and degree of neurological recovery. RESULTS: Seven patients are presented. The mean age at presentation was 52.1 years (range 41-66). All patients but one were male. All had a painful radiculopathic presentation. Relevant discopathy was observed from L2/3 to L5/S1, the commonest level being L3/4. Five were treated within 24 h of presentation, and two within 48 h. Three had concomitant cauda equina syndrome; of these, the first two made a full motor recovery, one by 6 weeks follow-up and the second on the same-day post-op evaluation. Overall, five out of seven cases had full resolution of their ankle dorsiflexion pareses. One patient with 1/5 power has not improved. Another with 1/5 weakness improved to normal on the one side and to 3/5 on the other. CONCLUSION: When bilateral foot drop occurs acutely, we encourage the consideration of degenerative spinal disease. Relevant discopathy was observed from L2/3 to L5/S1; aberrant innervation may be at play. Cauda equina syndrome is not necessarily associated with acute bilateral foot drop. The prognosis seems to be pretty good with respect to recovery of the foot drop, especially if partial at presentation and if treated within 48 h.