Sciatic nerve palsy after direct anterior approach for total hip replacement.

SummarySciatic nerve injury after total hip replacement is rare with a reported incidence of about 0.09%-3.7%. The most commonly reported causes include traction on the nerve during reduction, compression of the nerve from subfascial haematoma, significant leg lengthening, improper retractor placement, thermal burns from cautery and extraneous cement. We present a case of complete sciatic nerve palsy in a patient operated on using direct anterior approach (DAA). To date, there are no reports describing sciatic nerve palsy secondary to haematoma immediately after primary arthroplasty through the DAA. We performed an MRI of lumbosacral spine with both hips, which revealed a haematoma. Consequently, we promptly took the patient to the operation theatre for re-exploration. Using the same approach, we dislocated the hip and removed the clots. By the end of 2 weeks, the patient was able to dorsiflex the ankle and had fully recovered from sciatic nerve palsy.

Amphiphysin-IgG autoimmune sciatic neuropathy and facial neuropathy related to primary central nervous system lymphoma: A case report.

We reported a 61-year-old man presented with 10-month progressing left sciatic neuropathy and 10-day right facial neuropathy. Serum amphiphysin-IgG was positive. 18F-FDG PET/CT of the whole body showed no signs of malignancy. Treatment with plasma exchange and oral prednisone relieved the symptoms. Nine months later, right hemiparesis and seizure of right limbs developed. 18F-FDG and 18F-PBR06 (18 kDa translocator protein, TSPO) radioligand PET/MRI of the whole body revealed intense uptake in the intracranial lesions. Intracranial lymphoma was diagnosed by stereotactic needle brain biopsy. Mononeuropathies could be paraneoplastic syndromes. TSPO shows high uptake in intracranial lymphoma on 18F-PBR06 PET images.

Characterizing peroneal nerve injury clinicoradiological patterns with MRI in patients with sciatic neuropathy and foot drop after total hip replacement.

OBJECTIVE: Sciatic nerve injury following total hip arthroplasty (THA) predominantly affects the peroneal division of the sciatic nerve, often causing a foot drop. This can result from a focal etiology (hardware malposition, prominent screw, or postoperative hematoma) or nonfocal/traction injury. The objective of this study was to compare the clinicoradiological features and define the extent of nerve injury resulting from these two distinct mechanisms. METHODS: Patients who developed a postoperative foot drop within 1 year after primary or revision THA with a confirmed proximal sciatic neuropathy based on MRI or electrodiagnostic studies were retrospectively reviewed. Patients were divided into two cohorts: group 1 (focal injury), including patients with an identifiable focal structural etiology, and group 2 (nonfocal injury), including patients with a presumed traction injury. Patient demographics, clinical examinations, subsequent surgeries, electrodiagnostic study results, and MRI abnormalities were noted. The Student t-test was used to compare time to onset of foot drop and time to secondary surgery. RESULTS: Twenty-one patients, treated by one surgeon, met inclusion criteria (8 men and 13 women; 14 primary THAs and 7 revision THAs). Group 1 had a significantly longer time from THA to the onset of foot drop, with a mean of 2 months, compared with an immediate postoperative onset in group 2 (p = 0.02). Group 1 had a consistent pattern of localized focal nerve abnormality on imaging. In contrast, the majority of patients in group 2 (n = 11) had a long, continuous segment of abnormal size and signal intensity of the nerve, while the other 3 patients had a segment of less abnormal nerve in the midthigh on imaging. All patients with a long continuous lesion had Medical Research Council grade 0 dorsiflexion prior to secondary nerve surgeries compared with 1 of 3 patients with a more normal midsegment. CONCLUSIONS: There are distinct clinicoradiological findings in patients with sciatic injuries resulting from a focal structural etiology versus a traction injury. While there are discrete localized changes in patients with a focal etiology, those with traction injuries demonstrate a diffuse zone of abnormality within the sciatic nerve. A proposed mechanism involves anatomical tether points of the nerve acting as points of origin and propagation for traction injuries, resulting in an immediate postoperative foot drop. In contrast, patients with a focal etiology have localized imaging findings but a highly variable time to the onset of foot drop.

Posterior Hip Dislocation in Association With Anterior Column Acetabular Fracture, Femoral Head Fracture, and Sciatic Nerve Injury: A Case Report.

CASE: Posterior hip dislocations are classically associated with posterior acetabular wall fractures. We report the case of a 29-year-old man presented after a motorcycle accident with an unusual combination of injuries that included posterior hip dislocation, anterior column acetabulum fracture, femoral head fracture, and sciatic nerve injury. At the final follow-up, excellent outcomes were obtained with complete recovery of the sciatic nerve injury. CONCLUSION: A favorable outcome may be achieved in young patients who sustain this unusual compilation of ipsilateral anterior acetabulum fracture, posterior hip dislocation, femoral head fracture, and sciatic nerve injury with meticulous preoperative surgical planning and tailored patient management.

Early perioperative magnetic resonance findings in patients with foot drop following total hip Arthroplasty: A descriptive case-series.

PURPOSE: This study aims to characterize iatrogenic sciatic nerve injury patterns in the early, perioperative period following posterior-approach total hip arthroplasty (THA) with magnetic resonance imaging (MRI). METHODS: This was an IRB-approved retrospective analysis of patients acquired from a longitudinal, single site radiology database of patients who underwent MRI for "foot drop" within 4 weeks following posterior-approach THA surgery, over a 20-year period. RESULTS: MRI exams from 51 patients (mean age 62 years; 32 females) who met inclusion criteria were evaluated. Mean time to MRI was 2.4 days. Of 51 patients, 43 underwent primary THA, 6 revision THA and 2 explantation with antibiotic spacer placement. Ten exams revealed a normal appearance of the sciatic nerve. Nineteen showed compression of the sciatic nerve by edema or a fluid collection, without intrinsic nerve abnormality. Fifteen demonstrated perineural tethering or scar/granulation tissue encasement of the nerve, and in half of these cases the sciatic nerve was enlarged and/or hyperintense on fluid-sensitive sequences. Six patients had sciatic nerve compression secondary to quadratus femoris retraction. Six patients had complete resolution of the foot drop at a mean follow-up of 37.3 months following surgery, and in these cases the sciatic nerve appeared normal on the initial postoperative MRI. Remaining patients all had persistent weakness and paresthesias in the sciatic nerve distribution at a mean follow-up duration of 34.3 months. CONCLUSION: This retrospective case series demonstrates various sciatic nerve injury patterns in the early perioperative period on MRI and proposes a targeted MRI protocol to evaluate the sciatic nerve post THA surgery.

Risk of Postoperative Sciatic Nerve Palsy After Posterior Acetabular Fracture Fixation: Does Patient Position Matter?

OBJECTIVES: To determine whether the prone or lateral position is associated with postoperative sciatic nerve palsy in posterior acetabular fracture fixation. DESIGN: Retrospective cohort study. SETTING: Three Level I trauma centers. PATIENTS: Patients with acetabular fractures treated with a posterior approach (n = 1045). INTERVENTION: Posterior acetabular fixation in the prone or lateral positions. OUTCOME MEASUREMENTS: The primary outcome was the prevalence of postoperative sciatic nerve palsy by position. Secondary outcomes were risk factors for nerve palsy, using multiple regression analysis and propensity scoring. RESULTS: The rate of postoperative sciatic nerve palsy was 9.5% (43/455) in the prone position and 1.5% (9/590) in the lateral position ( P < 0.001). Intraoperative blood loss and surgical duration were significantly higher for patients who developed a postoperative sciatic nerve palsy. Subgroup analysis showed that position did not influence palsy prevalence in posterior wall fractures. For other fracture patterns, propensity score analysis demonstrated a significantly increased odds ratio of palsy in the prone position [aOR 7.14 (2.22-23.00); P = 0.001]. CONCLUSIONS: With the exception of posterior wall fracture patterns, the results of this study suggest that factors associated with increased risk for postoperative sciatic nerve palsy after a posterior approach are fractures treated in the prone position, increased blood loss, and prolonged operative duration. These risks should be considered alongside the other goals (eg, reduction quality) of acetabular fracture surgery when choosing surgical positioning. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Sciatic Neuralgia Case of an Entrapment Neuropathy Mimicking Piriformis Syndrome Due to Soft Tissue Hemangioma.

BACKGROUND: Lumbosacral pain is commonly seen in daily clinical practice. In fact, entrapment of the part of the sciatic nerve after the sacral foramen causes some of these pains, which should not be overlooked. The sciatic nerve may be compressed during its course after the sacral foramen for a variety of reasons. We aimed in this article to review extra-spinal compressive sciatic neuropathy reasons and abnormal magnetic resonance imaging (MRI) by presenting a sciatic neuralgia case of an entrapment neuropathy mimicking piriformis syndrome due to soft tissue hemangioma. CASE PRESENTATION: A 30-year-old male patient was admitted with complaints of lumbosacral pain spreading to the leg that had been worsening over the previous 10 days. With the preliminary diagnosis of labral damage and piriformis syndrome, the patient was referred to the radiology clinic for a hip MRI. In the hip MR images, a mass lesion suggestive of heterogeneously enhanced soft tissue hemangioma after the injection of paramagnetic contrast material was observed in the proximal left thigh. The soft tissue hemangioma extends towards the obturator foramen and compresses the sciatic nerve proximal to the femur after the sciatic foramen. CONCLUSION: The diagnosis of lower extremity entrapment neuropathy is frequently misdiagnosed. In these cases, MRI becomes more important for accurate diagnosis. The radiologists' knowledge of the sciatic nerve in MRI, regional anatomy during the course of the sciatic nerve, and abnormal nerve imaging findings will aid in the diagnosis.

Open Sciatic Nerve Decompression for Compartment Syndrome after Prolonged Lithotomy Position: A Case Report.

Background: Position-related compressive nerve injury is a frequently reported complication of the lithotomy position. In contrast, compartment syndrome-induced neuropathy after lithotomy with prolonged surgery is rare and prone to misdiagnosis. This case describes the successful open decompression of sciatic neuropathy due to compartment syndrome after a prolonged lithotomy position. Case presentation: A 56-year-old male patient complained of an abnormal sensation in the lower leg and difficulty in dorsiflexion and plantarflexion of the left foot and toes after laparoscopic anterior hepatic sectionectomy for 16 h in a lithotomy position. Physical examination revealed severe pain and paresthesia below the distal left thigh. In manual muscle test grading, dorsiflexion and plantarflexion of the left ankle and toes were classified as grade 1. Computed tomography and magnetic resonance imaging showed ischemic changes in the mid-thigh posterior muscles, and the sciatic nerve was severely swollen at the distal thigh, which was compressed by the proximal edge of the well-leg holder. After debridement of the necrotic tissue and decompression of the sciatic nerve, the pain subsided immediately, and the ankle and toe dorsiflexion motor function improved to grade 4. Conclusions: Most case reports of compressive neuropathy associated with the lithotomy position have been related to conservative treatment. However, if a lesion compressing the nerve is confirmed in an imaging study and the correlation with the patient's symptoms is evident, early surgical intervention can be an effective treatment method to minimize neurological deficits.

Amyloid Deposition: An Unusual Case of Deep Gluteal Syndrome and Sciatic Nerve Compression: A Case Report.

CASE: Soft-tissue amyloidomas are exceedingly rare, with only a few cases reported in the literature. There are no reports of sciatic nerve compression secondary to a soft-tissue amyloidoma. We report a unique case of a 71-year-old man with an incidentally found amyloidoma who was initially believed to have deep gluteal syndrome. He had a favorable outcome after surgical decompression. CONCLUSION: For patients who do not have classic examination and electromyography/nerve conduction findings of piriformis syndrome, providers should explore other etiologies of peripheral nerve compression including soft-tissue amyloidoma.

"Floating Hip" and "Floating Knee" Associated with Hip Dislocation, Sciatic Nerve Palsy, and Patella Fracture: A Case Report.

CASE: We report a very rare case of simultaneous ipsilateral floating hip and floating knee (SIFHFK) injury with the neck of the femur and patella fracture and hip dislocation associated with sciatic nerve injury in a 45-year-old man after a road traffic accident. We adopted a staged approach for surgical fixation of the fractures after stabilization. At the latest 2 years follow-up, the patient was asymptomatic with satisfactory clinical outcome. CONCLUSION: SIFHFK injuries present a challenging and emergent clinical scenario and require extensive clinical experience, careful planning, and multidisciplinary teamwork because of the paucity of specific treatment protocols for the treatment of this complex injury.

Sciatic nerve injury after acetabular fractures: a meta-analysis of incidence and outcomes.

PURPOSE: To investigate the incidence and the outcome of post-traumatic and iatrogenic sciatic nerve palsy (SNP) associated with fractures of the acetabulum. The results of sciatic nerve grafting for treatment were also investigated. METHODS: PUBMED, SCOPUS and COCHRANE databases were searched for longitudinal observational studies reporting sciatic nerve palsy related to acetabular fractures in adult patients over the last 20 years. Data regarding patients demographics, type of acetabular fracture, rate of post traumatic and iatrogenic sciatic nerve palsies as well as recovery rate are reported. Studies were assessed for their quality. Random effects meta-analyses were carried out to pool overall proportions of SNP incidence and complete recovery. Variations in SNP incidence by main study characteristics were assessed by subgroup analysis and meta-regression. A narrative review of sciatic nerve grafting was also conducted. RESULTS: Twenty studies reporting 44 post-operative and 18 iatrogenic SNPs in 651 patients were reviewed. The pooled incidence of posttraumatic SNP was 5.1% (95% CI 2.7-8.2%). The pooled incidence of iatrogenic SNP was 1.4% (95% CI 0.3-2.9%). Complete recovery of post-traumatic and iatrogenic SNP occurred in 64.7% (95% CI 41.7-85.4%) and 74.1% (95% CI 31.5-100%), respectively. CONCLUSION: A favorable outcome of both post-traumatic and iatrogenic SNP related to acetabular fractures has been found. Due to the poor results of sciatic nerve grafting, a "wait and see" approach may be the best option, in cases of a contused but anatomically intact sciatic nerve.

Overexpression of miR-378 Alleviates Chronic Sciatic Nerve Injury by Targeting EZH2.

In numerous studies, microRNAs (miRNAs) have been authenticated to play vital roles in the pathophysiology of neuropathic pain and other neurological diseases. In our study, we focused on evaluating miR-378 and its potential effects in neuropathic pain development, as well as the underlying molecular mechanisms. Primarily, a chronic sciatic nerve injury (CCI) rat model was established. Next, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was employed to measure the expression levels of miR-378 and EZH2 mRNA; the EZH2 protein expression levels were detected by western blot. A luciferase activity assay monitored the interaction of miR-378 and EZH2. Mechanical and thermal hyperalgesia was also performed to quantitate the effects of overexpression of miR-378 or EZH2 on the CCI rats. We found that miR-378 was down-regulated in the CCI rats, and the overexpression of miR-378 produced significant relief in their pain management. EZH2 was the downstream gene of miR-378 and was negatively regulated by miR-378. The up-regulation of EZH2 reduced the inhibitory effects of miR-378 on the development of neuropathic pain in the CCI rats. miR-378 acts as an inhibitor in the progression of neuropathic pain via targeting EZH2; the miR-378/EZH2 axis may be a novel target for the diagnosis and therapy of neuropathic pain in clinical treatment.

Pediatric sciatic neuropathy: Clinical presentation and long term follow up. / Neuropatía ciática en pediatría: Presentación clínica y seguimiento a largo plazo.

INTRODUCTION: Sciatic neuropathy is rare and difficult to diagnose in pediatrics, and its long-term course has not been completely understood. OBJECTIVE: To analyze the clinical presentation and evolution of a group of pediatric patients with sciatic neuropathy. PATIENTS AND METHOD: Retrospective anal ysis of the clinical characteristics of pediatric patients with sciatic neuropathy treated in two hospitals of Santiago between 2014 and 2018. Locomotor examination, muscle trophism, deep tendon reflexes, gait, sensation, and pain were assessed. Sciatic nerve conduction study and electromyography (EMG) were performed, and magnetic resonance imaging (MRI) in three patients. RESULTS: Six patients were included with an average age of 11.8 years. The etiologies were traumatic (N = 2), by compression (N = 2), vascular (N = 1), and tumor (N = 1). All of the 6 patients presented foot drop and Achilles tendon hyporeflexia/areflexia, and 5 patients presented severe neuropathic pain. The EMG showed involvement of the sciatic nerve rami and dependent muscles. In two patients, a pelvic girdle and lower limbs MRI was performed, showing selective muscle involvement in sciatic territory. One patient underwent a lumbosacral plexus MRI, and subsequently histological study showing a benign neural tumor. Out of the three patients who were followed-up longer than one year presented motor sequelae and gait disorder. CONCLUSION: Sciatic neuropathy in the study group was secondary to different causes, predominantly traumatic and compressive etiologies. The three patients that were ina long-term follow-up presented significant motor sequelae. In most of the cases, neural injury wasassoci- ated with preventable causes, such as accidents and positioning in unconscious children, which is crucial in the prevention of a pathology with a high sequelae degree.

Split and partially entwined sciatic nerve following closed reduction of a dislocated hip prosthesis.

We present a case of split and partially entwined sciatic nerve by a femoral prosthesis following closed reduction of a dislocated hip replacement. This complication is very rare and there are only few cases reported in the literature, with even less accompanied by supporting MRI. We present MRI features of a split and partially entwined sciatic nerve around a hip prosthesis.

[Gluteal compartment syndrome after immobilization following opioid abuse]. / Gluteales Kompartmentsyndrom nach Liegetrauma bei Opiatabusus.

This article reports the case of a 42-year-old male patient, who sustained a gluteal compartment syndrome after drug-induced immobilization with subsequent rhabdomyolysis and sciatic nerve palsy. Unlike compartment syndrome of the forearm or lower leg, this is a rare condition. After immediate surgical decompression and installation of negative pressure wound treatment, hemofiltration in acute renal failure could be averted using forced diuresis. The sensorimotor function of the lower extremity improved already after the first treatment and secondary wound closure was possible after 1 week. The patient was discharged 11 days after admission with complete recovery of sensorimotor and renal functions.

Neuropatía ciática en pediatría: presentación clínica y seguimiento a largo plazo / Pediatric sciatic neuropathy: clinical presentation and long term follow up

Resumen: Introducción: La neuropatía ciática es una entidad infrecuente y de difícil diagnóstico en Pediatría. Su evolución a largo plazo no ha sido claramente definida. Objetivo: Analizar la presentación clínica y evolución de un grupo de niños con neuropatía ciática. Pacientes y Método: Análisis retrospectivo de las características clínicas de pacientes pediátricos con neuropatía ciática atendidos en 2 hospitales de Santiago, entre 2014-2018. Se evaluó examen motor, trofismo muscular, reflejos osteotendíneos, marcha, sensibilidad y dolor. Se estudió neuroconducción de nervio ciático, electromiografía (EMG) y en 3 pacientes, Resonancia Magnética (RM). Resultados: Se incluyeron 6 pacientes, edad promedio 11,8 años. Hubo 2 causas traumáticas, 2 compresivas, 1 vascular y 1 tumoral. Los 6 pa cientes debutaron con pie caído e hiporreflexia/arreflexia aquiliana; 5 pacientes presentaron dolor neuropático severo. La EMG mostró en todos los casos compromiso en nervios y musculatura de pendientes del nervio ciático. En 2 casos se realizó RM de cintura pélvica y extremidades inferiores, mostrando compromiso muscular selectivo en pierna en territorio ciático. En 1 caso, se realizó RM de plexo lumbosacro, y luego estudio histológico, que concluyeron un tumor neural benigno. En los 3 pacientes que tuvieron seguimiento mayor a un año, se observaron secuelas motoras, con marcha alterada. Conclusión: La neuropatía ciática en este grupo fue secundaria a diversas etiologías, predominando las traumático-compresivas. En los 3 casos que tuvieron seguimiento a largo plazo se observaron secuelas motoras significativas. En la mayoría la lesión se asoció a causas prevenibles como accidentes y posicionamiento en niños con compromiso de conciencia, lo que resulta fundamental en la prevención de una patología con alto grado de secuelas.

Abstract: Introduction: Sciatic neuropathy is rare and difficult to diagnose in pediatrics, and its long-term course has not been completely understood. Objective: To analyze the clinical presentation and evolution of a group of pediatric patients with sciatic neuropathy. Patients and Method: Retrospective anal ysis of the clinical characteristics of pediatric patients with sciatic neuropathy treated in two hospitals of Santiago between 2014 and 2018. Locomotor examination, muscle trophism, deep tendon reflexes, gait, sensation, and pain were assessed. Sciatic nerve conduction study and electromyography (EMG) were performed, and magnetic resonance imaging (MRI) in three patients. Results: Six patients were included with an average age of 11.8 years. The etiologies were traumatic (N = 2), by compression (N = 2), vascular (N = 1), and tumor (N = 1). All of the 6 patients presented foot drop and Achilles tendon hyporeflexia/areflexia, and 5 patients presented severe neuropathic pain. The EMG showed involvement of the sciatic nerve rami and dependent muscles. In two patients, a pelvic girdle and lower limbs MRI was performed, showing selective muscle involvement in sciatic territory. One patient underwent a lumbosacral plexus MRI, and subsequently histological study showing a benign neural tumor. Out of the three patients who were followed-up longer than one year presented motor sequelae and gait disorder. Conclusion: Sciatic neuropathy in the study group was secondary to different causes, predominantly traumatic and compressive etiologies. The three patients that were ina long-term follow-up presented significant motor sequelae. In most of the cases, neural injury wasassoci- ated with preventable causes, such as accidents and positioning in unconscious children, which is crucial in the prevention of a pathology with a high sequelae degree.

Experimental Characterization of the Chronic Constriction Injury-Induced Neuropathic Pain Model in Mice.

Number of ligations made in the chronic constriction injury (CCI) neuropathic pain model has raised serious concerns. We compared behavioural responses, nerve morphology and expression of pain marker, c-fos among CCI models developed with one, two, three and four ligations. The numbers of ligation(s) on sciatic nerve shows no significant difference in displaying mechanical and cold allodynia, and mechanical and thermal hyperalgesia throughout 84 days. All groups underwent similar levels of nerve degeneration post-surgery. Similar c-fos level in brain cingulate cortex, parafascicular nuclei and amygdala were observed in all CCI models compared to sham-operated group. Therefore, number of ligations does not impact intensity of pain symptoms, pathogenesis and neuronal activation. A single ligation is sufficient to develop neuropathic pain, in contrast to the established model of four ligations. This study dissects and characterises the CCI model, ascertaining a more uniform animal model to surrogate actual neuropathic pain condition.

Sciatic Nerve Intraneural Hematoma.

Intraneural hematomas are an uncommon cause of a focal mononeuropathy. When they do occur, it is usually in the setting of inherited or iatrogenic coagulopathies or as a consequence of injections targeting nerves. We report a man aged 68 years on warfarin therapy for a prior pulmonary embolism who presented with a 6-month history of progressive weakness of knee flexion and ankle movement, excruciating pain, and dense numbness in his posterior left thigh and below the knee, consistent with a severe high sciatic palsy. Imaging depicted a contiguous cystic mass of mixed T1 and T2 intensities involving the left sciatic nerve in the thigh, which was radiologically interpreted as a hip arthroplasty-associated pseudotumor. The patient underwent surgical exploration, which revealed a thick hemorrhagic pseudocompartment within the sciatic nerve. The histopathologic diagnosis was consistent with chronic hemorrhage. These impressive lesions should be included in the differential diagnosis of nerve masses.