Clinical Insights and Optimization of Surgical Approach for Lateral Femoral Cutaneous Nerve Injury/Entrapment: A Comprehensive Analysis of 184 Cases.

BACKGROUND: Entrapment or injury of the lateral femoral cutaneous nerve (LFCN) is being recognized with increasing frequency, often requiring a surgical approach to relieve symptoms. The presence of anatomic variations can lead to errors in diagnosis and intraoperative decision-making. METHODS: This study presents the experience of a single surgeon (T.W.T.) in managing 184 patients referred with clinical issues related to the LFCN. A comprehensive review of these cases was conducted to develop a prospective surgical management algorithm. Data on the LFCN's anatomic course, pain relief outcomes, comorbidities, body mass index, and sex were extracted from patients' medical charts and operative notes. Pain relief was assessed subjectively, categorized into "excellent relief" for complete pain resolution, "good" for substantial pain reduction with some residual discomfort, and "failure" for cases with no pain relief necessitating reoperation. RESULTS: The decision tree is dichotomized based on the mechanism of LFCN pathology: compression (requiring neurolysis) versus history of trauma, surgery, and/or obesity (requiring resection). Forty-seven percent of the patients in this series had an anatomic variation. It was found that failure to relieve symptoms of compression often indicated the presence of anatomic variation of the LFCN or intraneural changes consistent with a neuroma, even if adequate decompression was achieved. With respect to pain relief as the outcome measure, recognition of LFCN anatomic variability and use of this algorithm resulted in 75% excellent results, 10% good results, and 15% failures. Twenty-seven of the 36 failures originally had neurolysis as the surgical approach. Twelve of those failures had a second surgery, an LFCN neurectomy, resulting in 10 excellent, 1 good, and 1 persistent failure. CONCLUSION: This article establishes an algorithm for the surgical treatment of MP, incorporating clinical experience and anatomical insights to guide treatment decisions. Criteria for considering neurectomy may include a history of trauma, prior local surgery, anatomical LFCN variations, and severe nerve damage due to chronic compression.

Meralgia paresthetica.

Meralgia paresthetica is a common but probably underrecognized syndrome caused by dysfunction of the lateral femoral cutaneous nerve. The diagnosis is based on the patient's description of sensory disturbance, often painful, on the anterolateral aspect of the thigh, with normal strength and reflexes. Sensory nerve conduction studies and somatosensory evoked potentials may be used to support the diagnosis, but both have technical limitations, with low specificity and sensitivity. Risk factors for meralgia paresthetica include obesity, tight clothing, and diabetes mellitus. Some cases are complications of hip or lumbar spine surgery. Most cases are self-limited, but a small proportion of patients remain with refractory and disabling symptoms. Treatment options include medications for neuropathic pain, neurolysis, neurectomy, and radioablation, but controlled trials to compare efficacy are lacking.

Incidence of Nerve Palsies During Pavlik Harness Treatment for Developmental Dysplasia of the Hip: A Retrospective Cohort Study.

BACKGROUND: The Pavlik harness has been used for approximately a century to treat developmental dysplasia of the hip (DDH). Femoral nerve palsy is a documented complication of Pavlik harness use, with an incidence ranging from 2.5% to 11.2%. Rare reports of brachial plexus palsy have also been documented. The primary purpose of the current study was to evaluate the incidence of various nerve palsies in patients undergoing Pavlik harness treatment for DDH. Secondary aims were to identify patient demographic or hip characteristics associated with nerve palsy. METHODS: We performed a retrospective review of patients diagnosed with DDH and treated with a Pavlik harness from February 1, 2016, to April 1, 2023, at a single tertiary care orthopaedic hospital. Hip laterality, use of a subsequent rigid abduction orthosis, birth order, breech positioning, weight, and family history were collected. The median (and interquartile range [IQR]) or mean (and standard deviation [SD]) were reported for all continuous variables. Independent 2-sample t tests and Mann-Whitney U tests were conducted to identify associations between the variables collected at the initiation of Pavlik harness treatment and the occurrence of nerve palsy. RESULTS: Three hundred and fifty-one patients (547 hips) were included. Twenty-two cases of femoral nerve palsy (4% of all treated hips), 1 case of inferior gluteal nerve palsy (0.18%), and 2 cases of brachial plexus palsy (0.37%) were diagnosed. Patients with nerve palsy had more severe DDH as measured by the Graf classification (p < 0.001) and more severe DDH as measured on physical examination via the Barlow and Ortolani maneuvers (p = 0.003). CONCLUSIONS: Nerve palsies were associated with more severe DDH at the initiation of Pavlik harness use. Upper and lower-extremity neurological status should be scrutinized at initiation and throughout treatment to assess for nerve palsies. The potential for femoral, gluteal, and brachial plexus palsies should be included in the discussion of risks at the beginning of treatment. Families may be reassured that nerve palsies associated with Pavlik harness can be expected to resolve with a short break from treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Preoperative Ultrasound-Guided Localization of the Lateral Femoral Cutaneous Nerve: From Guide Wire to Novel Clip.

BACKGROUND AND OBJECTIVE: Lateral femoral cutaneous nerve (LFCN) decompression and transposition are surgical treatment options for meralgia paresthetica. Identifying the LFCN during surgery may be challenging, and preoperative localization is a valuable adjunct in this case. The objective of this study was to explore a new technique using preoperative ultrasound-guided clip localization (USCL) of the LFCN. METHODS: After Institutional Review Board approval, data were collected on patients who underwent both preoperative ultrasound-guided wire localization (USWL) and USCL over the past 13 years. Skin-to-nerve time was calculated prospectively. RESULTS: Fifty-six patients were identified, 51 had USWL and 5 had USCL; the skin-to-nerve median time was 7.5 and 6 minutes, respectively. Six wires were misplaced, and this was at the beginning of utilization of the USWL technique. There were no nerve injury, infection, or bleeding complications related to either wire or clip placement. CONCLUSION: USWL or USCL is safe and time-efficient in LFCN surgeries.

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.

[Two Cases of Femoral Nerve Palsy after Pelvic Surgery].

Postoperative femoral nerve palsy (FNP) is a rare complication associated with urologic surgery. Inappropriate use of retractors, use of lithotomy position, and prolonged surgery that lead to the femoral nerve compression have been reported as risk factors for FNP. Here, we report two cases of FNP after pelvic surgery. Case 1: A 47-year-old woman underwent ureterocystoneostomy for a giant ureterocele. On the first postoperative day, she developed muscle weakness and paresthesia in the left lower leg. An orthopedic surgeon diagnosed her with FNP associated with the surgery. Case 2: An 82-year-old woman underwent radical cystectomy for invasive bladder cancer. On the second postoperative day, she developed extension deficit in the left lower leg and was diagnosed with an iatrogenic FNP. Although this complication is infrequent, at onset, it leads to difficulty in walking and gait disturbance in the patient. As a result, it greatly reduces the patient's postoperative quality of life. Therefore, preventive measures should be taken to reduce the risk of this postsurgical nerve injury, such as appropriate placement of retractors and proper patient positioning during the operation.

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.

Anatomical Analysis of the Lateral Femoral Cutaneous Nerve and Its Passage beneath the Inguinal Ligament.

BACKGROUND: Meralgia paraesthetica is a mononeuropathy of the lateral femoral cutaneous nerve. According to the literature, the nerve travels beneath the inguinal ligament 1.3 to 5.1 cm medial to the anterior superior iliac spine. Compression at this site may cause pain and paresthesia. The aim of this study was to provide more accurate measurements to improve the diagnostic and surgical management of meralgia paraesthetica. METHODS: The lateral femoral cutaneous nerve was dissected bilaterally in 50 Thiel-embalmed human cadavers. Measurements were performed with a standard caliper at the superior and inferior margins of the inguinal ligament. The distance from the inner lamina of the anterior superior iliac spine to the medial margin of the lateral femoral cutaneous nerve was measured. Data were collected and statistical analysis was performed with R. RESULTS: Ninety-three lateral femoral cutaneous nerves of 50 cadavers were dissected. In 6 percent of cadavers, the lateral femoral cutaneous nerve could not be found. The mean distance from the inner lamina of the anterior superior iliac spine to the lateral femoral cutaneous nerve's medial border was 2.1 ± 1.3 cm (range, 0.2 to 6.4 cm; 95 percent CI, 1.8 to 2.4 cm) at the superior margin of the inguinal ligament and 1.9 ± 1.4 cm (range, 0.2 to 3.0 cm; 95 percent CI, 1.6 to 2.2 cm) at the inferior border of the inguinal ligament. CONCLUSION: This anatomical study shows that the majority of the lateral femoral cutaneous nerve passes beneath the inguinal ligament in a very narrow area of 0.6 cm.

Meralgia Paresthetica Caused by Surgery in the Park-Bench Position.

OBJECTIVE: Meralgia paresthetica (MP) is an entrapment neuropathy of the lateral femoral cutaneous nerve (LFCN). We report a rare case of MP after microvascular decompression (MVD) surgery in the park-bench position in a patient with hemifacial spasm. CASE: The patient was a nondiabetic 46-year-old woman (height: 155 cm, weight: 42 kg) who consumed alcohol infrequently. After a first MVD for right hemifacial spasm, the symptom recurred and she underwent a second MVD procedure in the park-bench position, after which hemifacial spasm resolved. However, she reported right anterolateral thigh pain and dysesthesia without motor weakness. The pain was limited to the LFCN area, and a pelvic compression test elicited a positive Tinel-like sign. Our preliminary diagnosis was MP. Because conservative therapy was ineffective, she underwent LFCN block 9 months after the second MVD procedure. Her pain improved dramatically and we made a definitive diagnosis of MP. There has been no recurrence after 30 months of observation, although she reported persistent mild dysesthesia in the LFCN area. CONCLUSION: MP is a rare complication after MVD surgery in the park-bench position. LFCN block can resolve symptoms and hasten diagnosis.

[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.

Risk factors of meralgia paresthetica after prone position surgery: Possible influence of operating position, laminectomy level, and preoperative thoracic kyphosis.

Obesity and a prolonged surgical duration are reported risk factors for meralgia paresthetica (MP) after prone position surgery; however, this fails to explain why MP seldom occurs after prone position craniotomy. We reviewed the incidence of MP after spinal surgery and craniotomy in the prone position and investigated whether unidentified factors are involved in the mechanism of postoperative MP. Between January 2014 and March 2020, we performed 556 prone position surgeries. We excluded patients aged ≤16 years and those who were comatose or who required redo-surgery, and reviewed 446 eligible patients (124 who underwent craniotomies and 322 who underwent posterior spinal surgeries). Postoperative MP occurred in 46 (10.3%) patients with a higher incidence after spinal surgery than after craniotomy (13.7% vs. 1.6%, p < 0.001). Among the 322 patients who received posterior spinal surgery, thoracic and lumbar laminectomies were associated with a higher incidence of MP than cervical laminectomy. Analyses limited to those patients who received thoracic and lumbar laminectomies revealed that the preoperative thoracic kyphosis (TK) angle was significantly greater in patients with MP than in those without MP (average TK angle, 38.9° vs. 23.1°; p < 0.001), and that the preoperative lumbar lordosis angle did not significantly differ between the two groups. Apart from the known predisposing factors, we found that thoracolumbar-sacral laminectomy in patients with a greater TK angle is also a risk factor for MP after prone position surgery.

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.

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.

Preoperative Ultrasound in Patients with Meralgia Paresthetica to Detect Anatomical Variations in the Course of the Lateral Femoral Cutaneous Nerve.

OBJECTIVE: Sometimes during surgery for meralgia paresthetica, it can be difficult to find the lateral femoral cutaneous nerve (LFCN). The aims of this study were to study the prevalence of different anatomical variations in patients, compare preoperative ultrasound (US) data with intraoperative findings, and investigate the effect of type of anatomical variation on duration of surgery and success rate of localizing the LFCN. METHODS: Fifty-four consecutive patients with idiopathic meralgia paresthetica who underwent either a neurolysis or neurectomy procedure were included. All patients preoperatively underwent US of the LFCN. Anatomical variations were categorized into type A, B, C, D, and E using the classification of Aszmann and Dellon. The cross-sectional area of the LFCN at the inguinal ligament and the distance of the LFCN to the anterior superior iliac spine were noted. Correlations with intraoperative findings were investigated, as well as the effect on duration of surgery and success rate of finding the LFCN. Clinical outcome was assessed using the Likert scale. RESULTS: The most frequent anatomical variant was type B (79%), followed by type C (9%), D (5%), and E (7%). No type A was encountered. Correlation between preoperative US and intraoperative findings was 100%. During surgery, the LFCN could be identified in all cases. Duration of surgery did not significantly vary for the different anatomical variants. CONCLUSIONS: Preoperative US is reliable in detecting anatomical variations of LFCN. This information can be very helpful in identifying the LFCN more frequently and easily during surgery, especially in more medial variants.

[Meralgia paresthetica after prolonged prone position at the intensive care unit among COVID-19 patients. A case report]. / Långvarigt bukläge på IVA kan öka risken för meralgia paresthetica.

Meralgia paresthetica (MP) is an entrapment syndrome that may cause loss of sensation, numbness, paresthesia and pain within the distribution of the lateral femoral cutaneous nerve. This condition is more common in persons with diabetes mellitus, obesity and in old age. MP has previously been described in patients that have undergone surgery in the prone position (PP) and in a case report of a patient with ARDS (Acute Respiratory Distress Syndrome) who was cared for in the intensive care unit (ICU). Due to the COVID-19 pandemic PP has been widely used for periods of 12-16 hours to improve oxygenation. At the rehabilitation unit at our hospital, we have identified cases of MP in patients with COVID-19 that have required this type of positioning for long periods in the ICU. We would like to draw attention to the fact that there is a risk of peripheral nerve injury in the event of prolonged PP and recommend extra controls, careful positioning and extra padding at the areas where peripheral nerves may be exposed to pressure.

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.

Spontaneous iliacus haematoma with femoral nerve palsy: an appeal to involve surgical teams early.

We report the case of a 68-year-old man who was placed on heparin as bridge therapy and subsequently developed an iliacus haematoma with associated femoral nerve palsy. His team involved the orthopaedic surgery team in delayed fashion after his symptom onset. Due to his active medical conditions, he did not undergo surgical decompression of his haematoma until late into his hospital course. Unfortunately, this patient did not regain meaningful function from his femoral nerve deficit. We believe this case highlights the high index of suspicion necessary for making this diagnosis as well as the repercussions of an untimely decompression for this acute, compressive neuropathy. Although we are surgeons and this is a surgical case, we hope to publish this case in a medical journal to raise awareness that surgical decompression does have a role in this diagnosis and should ultimately be pursued early in its course for optimal patient benefit.