Magnetic resonance imaging of femoral nerve injury in the setting of anterior approach total hip arthroplasty.

PURPOSE: To illustrate MRI findings in patients with femoral neuropathy following anterior approach total hip arthroplasty (THA). METHODS: This was a retrospective review of patients who underwent MRI for femoral neuropathy following anterior approach THA between January 1, 2010, and July 1, 2022. Included patients had no preexisting neurologic condition. Clinical and diagnostic data were collected. MRIs were reviewed in consensus by 2 musculoskeletal radiologists. RESULTS: A total of 115 patient records were reviewed, 17 of which were included in the final analysis (mean age 64 years; 11 females). Study subjects presented with weakness with hip flexion and knee extension and pain and numbness in the femoral nerve distribution. In 7 subjects, the femoral nerve appeared normal. In 5 subjects, the femoral nerve was hyperintense on fluid-sensitive fat-suppressed imaging. In 4 patients, mass effect on the femoral nerve by either ill-defined soft tissue edema (n = 2), seroma (n = 1), or heterotopic ossification (n = 1) was detected. Only 1 patient had a nerve transection. Patients were imaged at a median time of 8 months (range: 1 day to 11 years) following arthroplasty placement. Clinical follow-up was available in 8 patients, of whom half had complete symptomatic resolution and half had partial improvement at a mean follow-up time of 39.3 months (SD 51.1). Of these 8, 1 underwent revision arthroplasty, 1 had removal of hardware, and another had excision of heterotopic ossification. CONCLUSION: MRI provides a means to directly evaluate the femoral nerve following anterior approach THA in both the immediate and chronic postoperative periods.

Ultrasound of the Lateral Femoral Cutaneous Nerve: A Review of the Literature and Pictorial Essay.

We review the ultrasound (US) findings in patients who present with meralgia paresthetica (MP). The anatomy of the lateral femoral cutaneous nerve at the level where the nerve exits the pelvis and potential entrapment sites that can lead to MP are discussed. A wide range of pathological cases are presented to help in recognizing the US patterns of MP. Finally, our experience with US-guided treatment is discussed.

Suprainguinal Re-Resection of the Lateral Femoral Cutaneous Nerve in Persistence or Recurrence of Meralgia Paresthetica After Previous Transection: Results of a Case Series.

OBJECTIVE: Suprainguinal re-resection of the proximal nerve stump can be performed in case of persistent or recurrent symptoms of meralgia paresthetica after previous transection of the lateral femoral cutaneous nerve (LFCN). Currently, no long-term results for this procedure have been reported in the literature. METHODS: In this study, 20 consecutive patients with persistent (13 cases) or recurrent (7 cases) symptoms of meralgia paresthetica were reoperated at a mean interval of 16 months after the first transection of the LFCN. The proximal nerve stump was sent for histopathologic analysis of a potential traumatic neuroma. Outcome was assessed using a 5-point Likert scale, which was obtained at a mean interval of 3.5 years after the suprainguinal re-resection. RESULTS: The proximal stump of the LFCN was identified in 90% of the cases. Successful pain relief (Likert 1 or 2) was obtained in 65% of the patients. A neuroma was found in 11 cases (55%), mostly in recurrent cases after a pain-free interval. The indication for recurrence of symptoms more frequently resulted in successful pain relief (71%) compared with results for the indication for persistence of symptoms (62%). There was no correlation between the presence of a neuroma and the chance for pain relief. CONCLUSIONS: Suprainguinal re-resection of the LFCN can be a successful procedure, both for persistence and recurrence of symptoms of meralgia paresthetica after previous transection, with long-lasting pain relief. Several factors, however, should be considered before performing this relatively new technique in patients that are discussed in this article.

Treatment of meralgia paresthetica (Lateral Femoral Cutaneous Neuropathy): A meta-analysis of ultrasound-guided injection versus surgery.

PURPOSE: To compare ultrasound (US)-guided injections and surgery for the treatment of meralgia paresthetica (lateral femoral cutaneous neuropathy). METHODS: Two reviewers, independently, up to 10 October 2020 retrieved Studies that assessed the outcome of US-guided injections and surgery for the treatment of meralgia paresthetica from major medical libraries. Predefined inclusion and exclusion criteria were adopted. RESULTS: 399 studies were initially found, and the meta-analysis was conducted on 10 studies for a total of 149 patients. US-guided injections were done in three studies, surgery in seven studies. N = 38 % (57/149) of patients were treated with US-guided injection and 62 % (92/149) were treated with surgery. After US-guided injections, 85 % (49/57) of patients were treated successfully, whereas 80 % (74/92) were treated with surgery successfully from the clinical point of view. Differences were not statistically significant even with a slight heterogeneity of studies and outcome pooled on random-effect model. No comparative cohort study or RCT was conducted. CONCLUSION: This meta-analysis showed that there was no statistically significant difference in treatment of meralgia paresthetica with ultrasound-guided injection or surgery. A RCT to compare a standardized US-guided approach versus surgery is essential to compare these techniques properly.

Meralgia Paresthetica Caused by Melorheostosis Affecting the Ipsilateral Ilium: A Case Report.

CASE: A 51-year-old woman presented with a 2-month history of pain in the right thigh. Radiography and computed tomography of the pelvis showed cortical hyperostosis of the right ilium. She was diagnosed with meralgia paresthetica (MP) caused by melorheostosis involving the right ilium. After 6 weeks of conservative management, an operation was performed for the persisting pain. At the 1-year follow-up, no findings of recurrence were observed clinically and radiographically. CONCLUSION: MP, caused by proximal irritation of the lateral femoral cutaneous nerve, can occur because of melorheostosis, which is a rare condition.

Femoral nerve compression caused by a hibernoma in the right thigh: a case report and literature review.

BACKGROUND: A hibernoma, also known as a brown fat tumor, is a rare benign soft tissue tumor, which originates from brown adipose tissue remaining in the fetus after the gestational period. It is often detected in adult men, presenting as a painless slow-growing mass. Hibernomas of the thigh have been reported; however, motor and sensory disorders caused by the tumors compressing the femoral nerve have not been reported. We report a case of a histopathologically proven hibernoma that induced femoral mononeuropathy. CASE PRESENTATION: A 26-year-old man was admitted to the hospital due to a mass, approximately 11.0 × 9.0 × 4.0 cm in size, that had developed 5 years ago in the anterolateral aspect of the proximal thigh. Furthermore, he had a history of hypoesthesia 1 month prior to his admission. He had signs and symptoms of both a motor and sensory disorder, involving the anterior aspect of the right thigh and the medial aspect of the calf, along the distribution of the femoral nerve. During surgery, the femoral nerve was found to be compressed by the giant tumor. The resultant symptoms probably caused the patient to seek medical care. Marginal resection of the mass was performed by careful dissection, and the branches of the femoral nerve were spared. Histopathology examination showed findings suggestive of a hibernoma. At the 4-month follow-up, no femoral nerve compression was evident, and local tumor recurrence or metastasis was not found. CONCLUSIONS: Asymptomatic hibernomas do not require treatment; however, in cases of hibernomas with apparent symptoms, complete marginal surgical excision at an early stage is a treatment option because it is associated with a low risk of postoperative tumor recurrence.

Use of Ultrasound as an alternative diagnostic method for the detection of Meralgia Paresthetica.

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Ultrasound-Guided Injections at the Lateral Femoral Cutaneous Nerve: The Inguinal Ligament as a Barrier.

BACKGROUND: Ultrasound-guided perineural injections at the lateral femoral cutaneous nerve (LFCN) may confirm the correct diagnosis and provide symptom relief in meralgia paresthetica. Although correct visualization of the nerve is generally described as feasible, failure rates of the procedure may be as high as 30%. OBJECTIVES: This study investigated the spread of injected fluids in ultrasound-guided perineural injections at the LFCN. The aim of the study was to evaluate whether the inguinal ligament impedes the distribution of injected fluids along the course of the LFCN. STUDY DESIGN: We used a descriptive research design. SETTING: Research was conducted at an anatomical research facility. METHODS: In fresh, nonembalmed cadavers, 2 mL of ink were injected with ultrasound-guidance at the LFCN below the inguinal ligament. The course of the nerve was then dissected to show the extent of nerve staining. RESULTS: Spread of the injected ink proximal to the inguinal ligament was found in 67.65% of specimens, while the ink did not pass the inguinal ligament in 32.35%. Concerning proximal spread, specimen body mass index was not of any relevance. LIMITATIONS: This cadaver study is only a simulation of the real clinical setting and does not allow any insight into the efficacy of the injection in living patients. CONCLUSIONS: The inguinal ligament is a barrier in the distribution of injected fluids in about one-third of specimens. This might be a major cause of failure in ultrasound-guided injections. The results from our study are in line with previously published failure rates and our findings might provide the anatomic basis to advance injection techniques. KEY WORDS: Cadaver study; injection; lateral femoral cutaneous nerve; LFCN; meralgia paresthetica; nerve entrapment; sonography; ultrasound.

[Meralgia paraesthetica].

This review summarises the treatment of meralgia paraesthetica. The condition is easy to recognise clinically, and in most cases the effect of conservative treatment is good. In case of persistent symptoms, further work-up is recommended including neurophysiological testing and ultrasound examination. If surgery is decided, we recommend nerve decompression primarily, since this procedure holds a success rate of 60-70%. In case of persistent symptoms, neurectomy should be performed. Ultrasound examination immediately before surgery can be helpful in localising the nerve and shortening procedural time.

Neuropatía femoral: hematoma en músculo ilíaco y fractura vertebral lumbar / Femoral neuropathy: haematoma in iliac muscle and a lumbar vertebral fracture

Paciente de 75 años con antecedentes de fibrilación auricular anticoagulada con acenocumarol, que presenta dolor, impotencia funcional e parestesias de extremidad inferior derecha tras caída sobre región sacro-coccigea. En pruebas complementarias se evidencia fractura vertebral L5 y hematoma sobre músculo ilíaco derecho, procediéndose a drenaje quirúrgico, suspensión de acenocumarol, e inicio de apixaban. Tras el tratamiento persiste neuropatía femoral, que ha impedido la completa recuperación funcional. DISCUSIÓN: Neuropatía femoral de posible causa por compresiva por hematoma del iliopsoas o radicular por estenosis de canal lumbar y contacto con raíz L4, observando en ambos casos debilidad de musculatura proximal de extremidad inferior. Sospecha hematoma ante dolor lumbar, masa en flanco o hipovolemia. Manejo controvertido e individualizado en función de la severidad de la sintomatología, desde conservador a drenaje quirúrgico para reducir secuelas y complicaciones hemorrágicas. Apixaban ha mostrado mayor perfil de seguridad. La estabilización de fractura lumbar permitió recuperación funcional parcial

75-year-old patient with a history of acenocumarol anticoagulated atrial fibrillation, which shows pain, functional impotence and right lower limb paresthesias after fall. Studies evidenc evertebral fracture L5 and haematoma on right iliac muscle, proceeding to surgical drainage, suspension of acenocumarol, and onset of apixaban. After treatment persisted femoral neuropathy, which not allowed complete functional recovery. DISCUSSION: Femoral neuropathy as possible cause of compressive hematoma over iliopsoas muscle or secundary to lumbar canal stenosis and contact with L4 root. In both of the misit posible to observe weakness of proximal lower limb musculature. Haematoma was suspected due to lower back pain, flank mass and hypovolemia. Handlingis based on the severity of the symptomatology, from conservative to surgical drainage to reduce sequelae and bleeding complications. Apixaban has shown a higher safety profile. Stabilization of lumbar fracture allowed partial functional recovery

Sonographic evaluation of the lateral femoral cutaneous nerve in meralgia paresthetica.

OBJECTIVE: Identify sonographic features of the lateral femoral cutaneous nerve (LFCN) in meralgia paresthetica (MP) and report therapeutic outcomes in sonographically confirmed cases. MATERIALS AND METHODS: Retrospective review of 50 patients with clinically suspected MP and 20 controls. Ultrasounds were reviewed for characteristics of the LFCN and compared between groups. When available, MRIs were reviewed. In cases of sonographically pathologic LFCN, subsequent therapeutic interventions were recorded. RESULTS: Thirty-five of the suspected MP cases (70%) had ultrasound findings suggestive of MP, 10 (20%) were negative, and in 5 (10%) the LFCN was not seen. Sonographic findings in positive cases included nerve enlargement in all cases (mean cross-sectional area 9 mm2 (standard deviation (SD) ± 5.59) versus 4 mm2 (SD ± 2.31) and 3 mm2 (SD ± 2.31) in negative cases and normal controls, respectively; p < 0.01), nerve hypoechogenicity (30 of 35 cases, 86%), and focal lesion (7 of 35 cases, 20%). Sixteen ultrasounds positive for MP had MRIs with only 4 (25%) reporting a concordant LFCN abnormality (enlargement or T2 hyperintensity). Twenty-five of the 35 (71%) patients with positive sonographic findings for MP had a US-guided LFCN block (local anesthetic ± corticosteroid), with 24 of 25 (96%) patients reporting immediate symptomatic improvement. Eighteen of 35 (51%) underwent LFCN neurectomy or neurolysis, all of whom experienced symptomatic improvement. CONCLUSION: Ultrasound is a useful modality for LFCN assessment in clinically suspected MP and is more sensitive for abnormalities than MRI. Nearly all patients who received perineural analgesia and/or neurectomy or neurolysis had symptomatic improvement.

Ultrasound-guided Musculoskeletal Interventions for the Most Common Hip and Pelvis Conditions: A Step-by-Step Approach.

Pain around the hip and pelvis is a very common condition. Pain may be generated within the joint space (i.e. the hip joint itself, the sacroiliac joints or the pubic symphysis) or from surrounding myotendinous, bursal, or nerve structures. Over the years, percutaneous musculoskeletal procedures have become increasingly popular to diagnose and treat painful conditions around the hip and the pelvis. Most intra- and extra-articular procedures are performed under ultrasound guidance. This article reviews the most common diagnostic and therapeutic procedures that can be performed around the hip and the pelvis under ultrasound guidance.

Selective Spinal Nerve Block in Ilioinguinal, Iliohypogastric and Genitofemoral Neuralgia.

AIM: To seek the efficacy of selective spinal nerve blocks in the treatment of groin pain that are irresponsive to peripheral nerve blocks. MATERIAL AND METHODS: This retrospective study comprised 17 patients with ilioinguinal, iliohypogastric, and genitofemoral neuralgias treated between 2017 and 2018. RESULTS: All patients received diagnostic peripheral nerve blocks and/or TAP blocks with blind or ultrasound-guided techniques. Four patients had ineffectual peripheral nerve blocks, after which they underwent T12 and L1 selective spinal nerve blocks. All four patients had satisfactory results. CONCLUSION: If distal peripheral nerve blocks are ineffective, an upper level nerve lesion, a lesion in the lumbar plexus or an L1 radiculopathy should be considered in ilioinguinal, iliohypogastric, and genitofemoral neuralgias. Upper level nerve blocks should be performed before deciding on surgery.

Role of MR Neurography in Groin and Genital Pain: Ilioinguinal, Iliohypogastric, and Genitofemoral Neuralgia.

OBJECTIVE: Chronic neuralgia of the border nerves (ilioinguinal, iliohypogastric, and genitofemoral) is difficult to diagnose and treat clinically. We examined the role of MR neurography (MRN) in the evaluation of border nerve abnormalities and the results of treatments directed at the MRN-detected nerve abnormalities. MATERIALS AND METHODS: This retrospective cross-sectional study included 106 subjects with groin or genital pain (mean [± SD] age, 50.7 ± 15.4 years) who showed mono- or multifocal neuropathy of the border nerves at 3-T MRN. Subjects who underwent CT-guided perineural injection were assessed for pain response. Injection responses were categorized as positive, possible positive, and negative. Subjects who received hyaluronidase, continuous radiofrequency ablation, or surgery were also evaluated for treatment outcomes. RESULTS: One hundred forty abnormal nerves were positive for neuropathy in 106 studies. Eighty of 106 subjects had single neuropathy, and 26 had multifocal neuropathy. Fifty-eight subjects underwent CT-guided perineural injections, with five receiving bilateral injections (63 injections). Improvement in subjective pain was seen in 53 of 63 cases (84.2%). A statistically significant improvement in pain response was noted in the isolated ilioinguinal nerve block group as compared with the isolated genitofemoral nerve block group (p = 0.0085). Thirteen of 58 subjects received multiple nerve injections at the same sitting. Both groups receiving single or multiple nerve injections had similar improvement in pain scores of 84% and 85%, respectively, although this difference was not statistically significant. CONCLUSION: Our retrospective analysis showed improved pain relief in subjects who underwent CT-guided nerve blocks on the basis of a positive MRN.

Femoral Neuropathy Following Transfemoral Neuroendovascular Procedures. An Analysis of a Prospective Registry.

BACKGROUND AND PURPOSE: Although femoral neuropathy is recognized as an adverse consequence following transfemoral neuroendovascular procedures, no reliable estimates are available. We analyzed data from a prospective registry to ascertain the frequency and characteristics of femoral neuropathy following transfemoral neuroendovascular procedures. METHODS: Consecutive patients who underwent neuroendovascular procedures through the transfemoral route were included. Detailed assessment was performed if any patient reported occurrence of sensory or motor symptoms in the femoral or lower extremity region including neurological examination (sensory/motor deficits) and femoral region ultrasound. RESULTS: Femoral neuropathy was diagnosed following 4 of 270 neurovascular procedures with an occurrence rate of 1.5% (95% confidence intervals = .4-3.7%). The symptoms were exclusively sensory without any motor involvement. The femoral neuropathy appeared to involve anterior femoral cutaneous nerves in all and medial cutaneous branches in 2 patients, and more than one nerve distribution in 1 patient in whom lateral cutaneous nerve appeared to be involved. All patients reported resolution of symptoms within a period ranging from 1 week to 2 months. No local hematoma or arterial pseudoaneurysm was identified at femoral region ultrasound. CONCLUSIONS: Femoral neuropathy is a rare occurrence following transfemoral neuroendovascular procedures and it usually occurs with pure sensory manifestations with complete resolution.

[Morphological study with ultrasound imaging in meralgia paraesthetica: in search of therapeutic efficiency]. / Estudio morfologico con ecografia en la meralgia parestesica: en busca de la eficiencia terapeutica.

TITLE: Estudio morfologico con ecografia en la meralgia parestesica: en busca de la eficiencia terapeutica.