Meralgia Paresthetica: Relevance, Diagnosis, and Treatment.

BACKGROUND: Pain and sensory disturbance in the distribution of the lateral femoral cutaneous nerve in the ventrolateral portion of the thigh is called meralgia paresthetica (MP). The incidence of MP has risen along with the increasing prevalence of obesity and diabetes mellitus and was recently estimated at 32 new cases per 100 000 persons per year. In this review, we provide an overview of current standards and developments in the diagnosis and treatment of MP. METHODS: This review is based on publications retrieved by a selective literature search, with special attention to meta-analyses, systematic reviews, randomized and controlled trials (RCTs), and prospective observational studies. RESULTS: The diagnosis is mainly based on typical symptoms combined with a positive response to an infiltration procedure. In atypical cases, electrophysiological testing, neurosonography, and magnetic resonance imaging can be helpful in establishing the diagnosis. The literature search did not reveal any studies of high quality. Four prospective observational studies with small case numbers and partly inconsistent results are available. In a meta-analysis of 149 cases, pain relief was described after infiltration in 85% of cases and after surgery in 80%, with 1-38 months of follow-up. In another meta-analysis of 670 cases, there was pain relief after infiltration in 22% of cases, after surgical decompression in 63%, and after neurectomy in 85%. Hardly any data are available on more recent treatment options, such as radiofrequency therapy, spinal cord stimulation, or peripheral nerve stimulation. CONCLUSION: The state of the evidence is limited in both quantity and quality, corresponding to evidence level 2a for surgical and non-surgical methods. Advances in imaging and neurophysiological testing have made the diagnosis easier to establish. When intervention is needed, good success rates have been achieved with surgery (decompression, neurectomy), and variable success rates with infiltration.

Unusual causes for meralgia paresthetica: systematic review of the literature and single center experience.

Meralgia paresthetica is often idiopathic, but sometimes symptoms may be caused by traumatic injury to the lateral femoral cutaneous nerve (LFCN) or compression of this nerve by a mass lesion. In this article the literature is reviewed on unusual causes for meralgia paresthetica, including different types of traumatic injury and compression of the LFCN by mass lesions. In addition, the experience from our center with the surgical treatment of unusual causes of meralgia paresthetica is presented. A PubMed search was performed on unusual causes for meralgia paresthetica. Specific attention was paid to factors that may have predisposed to LFCN injury and clues that may have pointed at a mass lesion. Moreover, our own database on all surgically treated cases of meralgia paresthetica between April 2014 and September 2022 was reviewed to identify unusual causes for meralgia paresthetica. A total of 66 articles was identified that reported results on unusual causes for meralgia paresthetica: 37 on traumatic injuries of the LFCN and 29 on compression of the LFCN by mass lesions. Most frequent cause of traumatic injury in the literature was iatrogenic, including different procedures around the anterior superior iliac spine, intra-abdominal procedures and positioning for surgery. In our own surgical database of 187 cases, there were 14 cases of traumatic LFCN injury and 4 cases in which symptoms were related to a mass lesion. It is important to consider traumatic causes or compression by a mass lesion in patients that present with meralgia paresthetica.

Diagnosis and treatment of meralgia paresthetica between 2005 and 2018: a national cohort study.

The prevalence of meralgia paresthetica (MP), which is caused by compression of the lateral femoral cutaneous nerve (LFCN), has been increasing over recent decades. Since guidelines and large-scale studies are lacking, there are substantial regional differences in diagnostics and management in MP care. Our study aims to report on current diagnostic and therapeutic strategies as well as time trends in clinical MP management in Germany. Patients hospitalized in Germany between January 1, 2005, and December 31, 2018, with MP as their primary diagnosis were identified using the International Classification of Disease (ICD-10) code G57.1 and standardized operations and procedures codes (OPS). A total of 5828 patients with MP were included. The rate of imaging studies increased from 44% in 2005 to 79% in 2018 (p < 0.001) and that of non-imaging diagnostic studies from 70 to 93% (p < 0.001). Among non-imaging diagnostics, the rates of evoked potentials and neurography increased from 20%/16% in 2005 to 36%/23% in 2018 (p < 0.001, respectively). Rates of surgical procedures for MP decreased from 53 to 37% (p < 0.001), while rates of non-surgical procedures increased from 23 to 30% (p < 0.001). The most frequent surgical interventions were decompressive procedures at a mean annual rate of 29% (± 5) throughout the study period, compared to a mean annual rate of 5% (± 2) for nerve transection procedures. Between 2005 and 2018, in-hospital MP care in Germany underwent significant changes. The rates of imaging, evoked potentials, neurography, and non-surgical management increased. The decompression of the LFCN was substantially more frequent than that of the LFCN transection, yet both types of intervention showed a substantial decrease in in-hospital prevalence over time.

Reconstruction of Quadriceps Function Using a Single Functional Gracilis Muscle Transfer With an Adductor Longus Nerve to Femoral Nerve Branch of the Rectus Femoris Nerve Transfer.

BACKGROUND: A femoral nerve injury may result in cutaneous sensory disturbances of the anteromedial thigh and complete paralysis of the quadriceps femoris muscles resulting in an inability to extend the knee. The traditional mainstay of treatment for femoral neuropathy is early physiotherapy, knee support devices, and pain control. Case reports have used the anterior division of the obturator nerve as a donor nerve to innervate the quadriceps femoris muscles; however, a second nerve transfer or nerve grafting is often required for improved outcomes. We suggest a novel technique of combining an innervated, pedicled gracilis transfer with an adductor longus to rectus femoris nerve transfer to restore the strength and stability of the quadriceps muscles. METHODS: This is a case series describing the use of a pedicled gracilis muscle transposed into the rectus femoris position with a concomitant nerve transfer from the adductor longus nerve branch into the rectus femoris nerve branch to restore quadriceps function after iatrogenic injury (hip arthroplasty) and trauma (gunshot wound). RESULTS: With electrodiagnostic confirmation of severe denervation of the quadriceps muscles and no evidence of elicitable motor units, 2 patients (average age, 47 years) underwent a quadriceps muscle reconstruction with a pedicled, innervated gracilis muscle and an adductor longus to recuts femoris nerve transfer. At 1 year follow-up, the patients achieved 4.5/5 British Medical Research Council full knee extension, a stable knee, and the ability to ambulate without an assistive aid. CONCLUSIONS: The required amount of quadriceps strength necessary to maintain quality of life has not been accurately established. In the case of femoral neuropathy, we assumed that a nerve transfer alone and a gracilis muscle transfer alone would not provide enough stability and strength to restore quadriceps function. We believe that the restoration of the quadriceps function after femoral nerve injury can be achieved by combining an innervated, pedicled gracilis transfer with an adductor longus to rectus femoris nerve transfer with low morbidity and no donor defects.

Surgical anatomy of the lateral femoral cutaneous nerve for meralgia paraesthetica: A simple technical guide for surgeons and trainees alike.

Meralgia paraesthetica is an entrapment neuropathy of the lateral femoral cutaneous nerve, usually due to compression at the inguinal ligament as the nerve passes from the pelvis into the thigh. Surgical decompression of the lateral femoral cutaneous nerve is a simple and effective treatment option, but the surgical anatomy of the area is not always familiar to neurosurgeons and neurosurgical trainees alike. This paper is a simple review of the relevant surgical anatomy and the surgical steps of lateral femoral cutaneous nerve decompression, with the aim of providing the busy surgeon and trainee a quick and easy reference guide to the procedure.

[Decompression of the lateral femoral cutaneous nerve of the thigh : Treatment of meralgia paresthetica]. / Operative Dekompression des Nervus cutaneus femoris lateralis : Behandlung der Meralgia paraesthetica.

OBJECTIVE: Treatment of non-responding pain to conservative treatment located at the anterolateral thigh with surgical decompression of the lateral femoral cutaneous nerve of the thigh (LFCN). INDICATIONS: Compression syndrome of the LFCN; patients suffering from the following symptoms: pain (dysesthesia), numbness (paresthesia), hypersensibility to temperature (or temperature changes) along the course of the LFCN located at the anterolateral thigh. CONTRAINDICATIONS: A new or recrudescent hernia with additional pain or recent laparoscopic hernia repair as a supposed iatrogenically induced compression of the LFCN. SURGICAL TECHNIQUE: Dissection and release of the LFCN of connective tissue, scar tissue, bone rims, and retraction located along the passage underneath the inguinal ligament and distally. POSTOPERATIVE MANAGEMENT: Suture removal after 10-14 days, no sports for 2 weeks. Physiotherapy if necessary. Neurography 4 months after surgery (obligatory if symptoms are persistent). The patient should be followed up for about 24 months. RESULTS: Of the patients, 69% had a history of trauma or surgery, which were designated as the onset of pain. Of these patients, 78% had hip prostheses and 22% had previous falls. Postoperatively, a significant reduction of pain of 6.6 points on the numeric rating scale was observed. All other evaluated parameters also improved postoperatively. Patient satisfaction was high, with 86% reporting complete satisfaction, and 14% reporting partial satisfaction.

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.

Adductor magnus muscle transfer to restore knee extension: Anatomical studies and clinical applications.

BACKGROUND: Loss of knee extension causes significant impairment. Though nerve-based reconstruction is preferable in cases of femoral nerve palsy or injury, these surgeries are not always appropriate if the pathology involves the quadriceps muscles or presentation too late for muscle reinnervation. Muscle transfers are another option that has been underutilized in the lower extremity. We describe the successful restoration of knee extension by adductor magnus muscle transfer without functional donor morbidity, along with anatomical considerations. METHODS: Ten fresh frozen cadaveric lower limbs were dissected at the groin and thigh. In addition, three patients presented with femoral nerve palsy for which nerve-based reconstruction was not appropriate because of late presentation. In these patients, adductor magnus muscle transfers were performed, along with sartorius, gracilis, and tensor fasciae latae transfers if available and healthy. RESULTS: In cadavers, the pedicle for the adductor magnus is at the level of the gracilis and adequate for muscle transfer, with sufficient weavable tendon length. The only major structure at risk is the femoral neurovascular bundle, which is in a reliable anatomic position. Two patients recovered 4/5 active knee extension and ambulation without assistive devices. A third required reoperation for a loosened tendon weave, after which the noted improved stability and strength with ambulation but did not regain strong active knee extension and continued to require a cane. CONCLUSIONS: We present a novel reconstructive approach for loss of quadriceps function in patients, which yields good clinical outcomes, with anatomic and technical details to demonstrate the utility of this technique. Ongoing evaluation of optimal technique and rehabilitation to maximize functional outcomes is still needed.

Medical and surgical treatment of meralgia paresthetica.

Meralgia paresthetica (MP) is a painful mononeuropathy that causes paresthesia, tingling, stinging or a burning sensation in the thigh's anterolateral part due to the entrapment of the lateral femoral cutaneous nerve under the inguinal ligament. The treatment options for MP include conservative or interventional management and must follow an algorithm. The objective is to eliminate the underlying cause if known. In the present study, four patients with MP who were successfully treated with either conservative or interventional management are presented. The advantages and disadvantages of neurolysis (decompression and transposition) and neurectomy procedures for surgical treatments are discussed.

Lay abstract Meralgia paresthetica (MP) is a tingling, stinging or burning sensation on the thigh due to the compression of the nerve that gives sensation to the skin on the thigh. Constrictive clothing, obesity and pregnancy are common causes of MP. However, it can also be caused by local trauma or diseases such as diabetes. In most cases, MP can be treated with preventive measures such as wearing loose-fitting clothes and losing weight. In severe cases, treatment may require surgery.

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.

Repair of the femoral nerve by two motor branches of the obturator nerve: A case report.

Complete femoral nerve palsies are uncommon but devastating injuries when they are caused by large nerve defects. Direct repair is usually not possible and nerve grafting renders uncertain outcomes. Recent studies proposed different peripheral nerve transfers as treatment strategies for large femoral nerve defects. We report a clinical application of a nerve transfer to reinnervate the quadriceps muscle with two motor branches of the obturator nerve in a 48 years-old man that was diagnosed with a femoral nerve palsy after resection of a retroperitoneal schwannoma. The branches supplying the gracilis and adductor longus muscles were transferred to the motor branch of the femoral nerve to the quadriceps muscle at 6 months postinjury. At 34 months of follow-up, knee extension was quoted M4. The presented nerve transfer may be feasible, technically simple, and renders good functional outcomes.

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.

Laparoscopic-Assisted Intra-Abdominal Section of the Lateral Femoral Cutaneous Nerve for Meralgia Paresthetica Following Anterior Hip Arthroplasty.

BACKGROUND: Meralgia paresthetica, a pain syndrome that is caused by injury to the lateral femoral cutaneous nerve, is a well-documented complication after anterior hip arthroplasty (THA). Traditional treatment of this peripheral nerve entrapment syndrome can be complicated in patients who have had THA via an anterior approach owing to the presence of scar in the postoperative bed. CASE DESCRIPTION: In a 70-year-old man, we performed a novel laparoscopic-assisted intra-abdominal approach to treat meralgia paresthetica in the setting of previous anterior THA. CONCLUSIONS: Minimally invasive intra-abdominal treatment of meralgia paresthetica following anterior THA results in durable pain relief. This approach is a helpful alternative to traditional techniques of decompression or section of the lateral femoral cutaneous nerve below the inguinal ligament.

Histopathologic changes inside the lateral femoral cutaneous nerve obtained from patients with persistent symptoms of meralgia paresthetica.

BACKGROUND: In patients with persistent symptoms of meralgia paresthetica, a neurectomy of the lateral femoral cutaneous nerve (LFCN) can be performed to alleviate pain symptoms. The neurectomy procedure can be performed either as a primary procedure or after failure of a previously performed neurolysis or decompression of the LFNC (secondary neurectomy). The goal of the present study was to quantify the histopathologic changes inside the LFCN obtained from patients with persistent symptoms of meralgia paresthetica, and specifically to compare to what extend these changes are present after primary versus secondary neurectomy. METHODS: A total of 39 consecutive cases were analyzed microscopically: in 29 cases, the neurectomy had been performed as primary procedure, in 10 cases, after failed neurolysis. Intraneural changes were quantified for the (1) thickening of perineurium, (2) deposition of mucoid, and (3) percentage of collagen. Analysis was performed at three levels: proximal to, at, and distal to the previous site of compression. In addition, correlations were investigated for the duration of symptoms and the body mass index (BMI) of the patient. RESULTS: Intraneural changes were found consistently in all cases. There was no significant difference for the primary and secondary neurectomy groups. There was also no relation with the previous site of compression. There was a weak correlation between the occurrence of intraneural changes and the duration of symptoms, although this difference was not statistically significant. CONCLUSIONS: Histopathological changes in this study were found in all patients with persistent symptoms of meralgia paresthetica regardless of a previously performed neurolysis procedure. This finding suggests that the intraneural changes that occur in persistent meralgia paresthetica are largely irreversible and support the surgical strategy of neurectomy as an alternative to neurolysis, also for primary surgical treatment and not only after failure of neurolysis.

Management of Irreducible Hip Dislocations in Infants With Developmental Dysplasia of the Hip Diagnosed Below 6 Months of Age.

BACKGROUND: Infants with dislocated irreducible (D/I) hips can be substantially harder to treat than infants with dislocated but reducible hips. The purpose of this study was to compare treatment methods and outcomes for infants with D/I hips in order to optimize management of this difficult patient cohort. METHODS: A multicenter prospective hip dysplasia study database was analyzed from 2010 to 2016. Infants aged below 6 months with clinically and radiologically confirmed D/I hips were included in the study. Teratological hips (syndromic/neuromuscular) were excluded. RESULTS: In total, 59 hips in 52 patients were included. All hips were clinically Ortolani negative and radiologically dislocated but irreducible on presentation and had at least 20 months of follow-up. Mean age at diagnosis was 1.9 months (range, 0.1 to 5.9 mo). There were 33 left hips, 12 right hips, and 14 bilateral hips (7 patients). In total, 48 of 59 hips were treated in Pavlik harness. The remainder were treated by alternative braces or primary closed or open reductions. Pavlik treatment was successful in 27 of 48 hips. Pavlik treatment was abandoned in 21 D/I hips, 3 due to femoral nerve palsy and the remainder due to failure to achieve reduction. There was no statistical correlation between Pavlik success and age at diagnosis (P=0.22), patient sex (P=0.61), or bilateral compared with unilateral D/I hips (P=0.07). Left hips were more likely to be successfully reduced in Pavlik harness than right hips (P=0.01). Five complications occurred: 3 patients developed femoral nerve palsy in Pavlik harness, while 2 patients developed avascular necrosis, both after failed Pavlik treatment and subsequent surgery. CONCLUSIONS: Pavlik harness treatment has been demonstrated to be a safe and sensible first-line treatment for infants with D/I hips. Left hips were more likely to be successfully reduced in Pavlik harness than right hips, but age, sex, and bilaterality were not correlated. The outcomes demonstrated from this multicentre prospective database inform management of this complex patient cohort. LEVEL OF EVIDENCE: Level II-prognostic study: less-quality prospective study.

Surgical options for meralgia paresthetica: long-term outcomes in 13 cases.

BACKGROUND: Meralgia paresthetica is an entrapment neuropathy of the lateral femoral cutaneous nerve that may cause paresthesias, pain, and sensory loss of the anterior and lateral thigh. Treatment is primarily medical. Surgery is an option for patients who do not respond to medical treatments. METHODS: Patients whose symptoms did not improve after medical and conservative treatment for at least 3 months were included in this study. These patients underwent neurolysis and decompression surgery and had a mean postoperative follow-up of 38 months. Their pain levels were assessed by the VAS scoring system. RESULTS: In 8 (61.5%) patients, the symptoms completely resolved within the first 3 months. In 5 (38.5%) patients, the complaints persisted partially and the recovery was observed after 12 months. In patients having a metabolic etiology, the duration of recovery was up to 12 months. CONCLUSION: The long term results of surgery are good though only partial improvemnts in reported pain were seen in the early postoperative period, especially in patients with a metabolic etiology.

Reparación de defecto de nervio femoral tras iatrogenia / Femoral nerve defect repair after iatrogenic injury

Las lesiones del nervio femoral, en su mayor parte, son secundarias a iatrogenia tras intervenciones quirúrgicas. Presentamos un caso de lesión del nervio femoral tras extirpación de un tumor retroperitoneal, con una recuperación funcional aceptable después de reparar el defecto nervioso con injertos de nervio sural. El defecto tenía 10 cm y la recuperación obtenida MRC (Medical Research Council) fue de 4/5. Consideramos que en estos casos, la reparación precoz es fundamental para obtener un resultado adecuado, incluso en situaciones en la que se necesitan largos injertos nerviosos

Femoral nerve injuries are mostly secondary to iatrogenic after surgical interventions. We present a case of lesion of the femoral nerve after the removal of a retroperitoneal tumor, with an acceptable functional recovery after repair of the defect with sural nerve grafts. The defect was 10 cm length and the recovery obtained MRC (Medical Research Council) was 4/5. We considerer that early repair is essential to obtain an acceptable result, even in situations of being necessary long nerve grafts

Femoral neuropathy following a psoas hitch vesicopexy.

A 68-year-old man classified as III on the American Society of Anaesthesiologists (ASA) physical status classification system, with a high-grade papillary urothelial cell carcinoma of the left distal ureter, underwent open retroperitoneal distal ureterectomy followed by a ureteroneocystostomy with a vesico-psoas hitch. Postoperatively, the patient complained of left proximal lower limb weakness, severe pain and hypaesthesia of the ventral left thigh suggestive of femoral neuropathy. After excluding common causes for postsurgical pain, a surgical re-exploration was eventually performed during which the sutures used in the vesicopexy were removed, resulting in almost complete resolution of the symptoms. Electromyographic analysis 4 weeks after discharge confirmed the diagnosis of femoral neuropathy, most likely caused by the sutures used in the vesicopexy. This is a rare complication with major consequences for postoperative recovery.