Femoral neuropathy …

General Neurology

Updated 01.29.2024
Released 11.21.1997
Expires For CME 01.29.2027

Femoral neuropathy

Authors: Christopher Doughty MD, Sarah Smith MD PhD

See Contributor Disclosures

Editor: Randolph W Evans MD

Femoral neuropathy

In This Article

Quick Link

Introduction

Overview

Femoral neuropathy is a rare but serious mononeuropathy of the lower extremity causing knee extension (quadriceps) and weakness (and at times hip flexion weakness), typically with numbness of the medial leg. If careful neurologic examination is not performed, symptoms may initially be attributed to orthopedic injury, such as pathology of the hip joint, muscle strain, or quadriceps tendon tear. Common causes include trauma, surgical procedures, and retroperitoneal hematoma. Nerve conduction studies and electromyography can confirm the diagnosis and offer prognostic information. Management remains controversial as some patients with mild cases will achieve good outcomes with conservative management. However, urgent surgical intervention may be prudent in cases caused by retroperitoneal hematoma leading to severe, progressive weakness.

Key points

	• The femoral nerve is a mixed sensorimotor nerve comprised of the ventral rami of spinal roots L2–L4.
	• Femoral neuropathy presents with quadricep weakness, numbness, and variable pain. Hip flexion weakness is observed in more proximal lesions, often acutely.
	• Examination typically reveals weakness of knee extension with absent or depressed patellar reflex and normal thigh adduction.
	• Most femoral neuropathies are caused by compression of the nerve either in the pelvis or beneath the inguinal ligament.
	• Nerve conduction studies and needle EMG are useful for diagnostic and prognostic purposes. Important alternative considerations in the differential diagnosis, such as lumbosacral radiculopathy and plexopathy, typically can be distinguished from femoral neuropathy using these studies.

Historical note and terminology

Early published literature led many to believe that diabetes mellitus is associated with femoral mononeuropathy. It is now clear that isolated femoral neuropathy in diabetics is rare, and most reported cases were mislabeled and were actually diabetic lumbosacral radiculoplexus neuropathy (also known as diabetic amyotrophy). Because this condition has become more widely recognized, no reliable reports of isolated diabetic femoral neuropathy have been published during the last 3 decades.

Clinical manifestations

Presentation and course

Femoral neuropathy presents with quadriceps weakness and numbness of the medial thigh and leg, often acutely. Patients frequently complain that their leg buckles underneath them. In cases of femoral neuropathy due to iliacus or retroperitoneal hematoma, there may be severe pain experienced over the anterior thigh in addition to the back, buttock, abdomen, and groin (31). Passive extension at the hip may be painful in these cases. Otherwise, groin or thigh pain is usually mild. The neurologic examination reveals weakness of knee extension (quadriceps) with absent or depressed patellar reflex. When the femoral nerve is injured in the pelvis, hip flexion (iliopsoas) may also be weak; however, hip flexion is spared in more distal lesions. Thigh adduction should be normal as these muscles are innervated by the obturator nerve. Hypoesthesia is common, involving the anteromedial thigh and medial calf. Sensory symptoms can include pain in the inguinal region, which forces the patient to hold the hip in the antalgic position of flexion and external rotation, as well as pain or dysesthesia at the anterior thigh and anteromedial leg. In most cases, the femoral neuropathy is unilateral, although bilateral femoral neuropathies may result from the lithotomy position or pelvic surgery.

Prognosis and complications

In a case series of 154 patients with femoral neuropathy, 36% had nearly complete recovery, 27% partially recovered, and 25% had minimal or no recovery (64). These data were strikingly similar to another study of 31 patients in which 31% of patients fully recovered, 34% had a good but incomplete recovery, and 31% had minimal to no recovery (40).

The prognosis for the recovery of muscle strength after femoral neuropathy depends mostly on whether the injury is axonal or demyelinating in nature. Findings on nerve conduction studies and EMG can determine this underlying pathophysiology. Therefore, they are often helpful in predicting the prognosis of weakness in acute femoral nerve lesions, with the single most useful piece of data being the estimate of motor axon loss based on nerve conduction studies.

The femoral nerve can be stimulated at the groin and a compound muscle action potential recorded from the rectus femoris. If the femoral CMAP amplitude is low or absent in the presence of moderate or severe weakness of the quadriceps, this suggests motor axon loss. The prognosis in such cases is relatively protracted as it will depend on axon sprouting and reinnervation. If CMAP is reduced to less than 50% of the amplitude of the contralateral response, less than 50% of patients recover over the next year. In contrast, all patients in a large case series with a femoral CMAP amplitude that was more than 50% of the amplitude of the contralateral response recovered by the end of 1 year (40). The amplitude should always be compared to the asymptomatic opposite side as this response can be technically challenging to obtain, even in normal individuals. Of note, measuring the saphenous (terminal sensory branch of the femoral nerve) sensory nerve action potential is often useful diagnostically, but it has less prognostic value than the compound muscle action potential.

In contrast, if the femoral CMAP amplitude is normal, a demyelinating lesion is implied. Focal slowing of conduction velocity and conduction block cannot be demonstrated because it is not possible to stimulate the femoral nerve at more proximal sites.

An important caveat in determining the pathophysiology and, thus, prognosis, is that the time since symptom onset must be considered. Even in cases of severe axonal injury, the femoral compound muscle action potential is likely to be normal in the hyperacute period because insufficient time has passed for Wallerian degeneration to occur. It typically takes 4 to 5 days for the compound muscle action potential amplitude to reach its nadir (15). Similarly, there are findings on needle EMG that can indicate axon loss, such as the presence of fibrillation potentials and positive sharp waves. However, these may not appear until 2 to 4 weeks after onset of injury and, therefore, are frequently not useful in gauging prognosis in the acute setting.

In comparison to other peripheral nerves, femoral neuropathy carries a relatively good prognosis, even when the lesion is due to axonal loss. This is, in part, due to a relatively short distance between common injury sites of the nerve and its target muscles (eg, iliacus and quadriceps), requiring regenerative sprouting to occur over a short distance. Demyelinating lesions may recover in 2 to 3 months by remyelination (02), whereas axonal lesions often require longer. The majority of femoral neuropathies after pelvic surgery may resolve with conservative management (08). Complete recovery is common in incomplete iatrogenic nerve injuries, particularly with regard to motor deficits, although residual sensory symptoms may remain (48).

Clinical vignette

A 69-year-old woman was admitted to the hospital because of acute chest pain. She underwent emergency cardiac catheterization and angioplasty through the right femoral artery. She was also placed on intravenous heparin. The next day, she noted severe right leg weakness with numbness in her thigh. She had moderate pain in her groin and anterior thigh. On the third day of admission, her neurologic examination revealed complete paralysis of the right quadriceps and iliopsoas. Thigh adductors and ankle dorsiflexion were normal. The right knee jerk was absent. There was a loss of touch and pain sensation over the anterior thigh and medial leg. Urgent CT scan of the pelvis revealed a large right retroperitoneal hematoma involving the iliacus muscle extending to the iliac crest. Surgical evacuation was done that day.

Her neurologic findings did not change. Nerve conduction studies administered on the tenth day revealed absent femoral compound muscle action potential and absent saphenous sensory nerve action potential on the right, with normal responses on the left. The sural sensory, tibial, and peroneal motor conduction studies were normal. Repeat nerve conduction studies on the third week were unchanged. Needle EMG revealed prominent fibrillation potentials and no voluntary motor units in the right quadriceps and iliacus. The right thigh adductors, tibialis anterior, and paraspinal muscles were normal.

Her recovery of neurologic functions was protracted. She required a knee brace (ankle-knee-foot orthosis) for ambulation. Six months later, the iliacus strength was Medical Research Council grade 4- of 5, and the quadriceps grade 3 of 5. She could not extend her knee actively beyond 160 degrees. Sensory loss was unchanged. EMG revealed nascent (reinnervation) motor unit potentials in the right iliopsoas and quadriceps. At 1.5 years, she did not require a brace, and her iliopsoas and quadriceps strengths were Medical Research Council grade 4 of 5. The right knee jerk was still absent. As a result of painful dysesthesia in the thigh and medial leg, she was placed on a tricyclic. At 3 years, she had an absent right knee jerk, mild weakness of the right iliopsoas and quadriceps (Medical Research Council grade 4+ of 5), and hyperesthesia of the medial leg.

Biological basis

Etiology and pathogenesis

Most femoral neuropathies are caused by direct trauma to, or compression of, the nerve either in the pelvis or beneath the inguinal ligament. Kim and colleagues reviewed 119 surgically treated femoral nerve injuries reported over the past 33 years and found that 52 of 89 (58%) traumatic lesions to the femoral nerve were iatrogenic in nature (36). Most frequently implicated were gynecological procedures, with others related to orthopedic operations, femoral nerve blocks, and femoral artery puncture. Common causes include the following.

Perioperative. In a case series cataloging all cases of femoral neuropathy at a single institution, 46% of cases occurred perioperatively. Of these, the authors estimate that 75% were due to stretch injury of the nerve, 11% were due to direct nerve compression, and 14% were due to lithotomy positioning. The types of procedures implicated include abdominal, pelvic, orthopedic, and gynecologic and are detailed below (64).

Femoral neuropathy during pelvic and abdominal surgery. Iatrogenic injury to the femoral nerve during pelvic surgery is well documented. In some series, the incidence of femoral neuropathy after abdominal hysterectomy and after renal transplantation has been reported to be up to 11% and 2%, respectively (41; 22; 67; 60). Various pelvic surgeries utilizing retractor blades, particularly self-retaining retractor blades, may carry specific risk (41; 32; 29; 10; 48). During these surgical procedures, the femoral nerve becomes compressed between the lateral blade of the retractor and the pelvic wall. One study reported that the incidence of femoral neuropathy after abdominal hysterectomies was significantly decreased when retractors were not used (22). A small case series highlighted the features of femoral neuropathy following kidney transplantation: self-retaining retractors were used in all cases, and patients had good motor recovery anywhere from 3 to 313 days following the onset of symptoms (37).

Misplaced sutures are also a reported cause of femoral nerve injury in urologic procedures (49). Pelvic internal fixation device placement can be associated with femoral nerve injury (24). Although not a specifically intrapelvic procedure, lateral retroperitoneal transpsoas approaches to lumbar spinal surgery have also been highlighted as a cause of femoral neuropathy. One series described that 6 of 230 patients undergoing this approach to lumbar interbody fusion developed femoral neuropathy – five of these were due to direct nerve injury, whereas one was due to hematoma. All patients had significant neurologic improvement within 1 year (01).

Femoral neuropathy due to hip replacements and other orthopedic procedures. Femoral neuropathy is a very rare complication of hip replacement surgery but may be more common with hip revision surgery and reconstructions. A large study of 27,004 primary total hip arthroplasty cases at a single institution found an incidence of 0.17% (47 cases) for motor nerve palsy of any nerve, but only three of these involved the femoral nerve (20). Peroneal and sciatic nerve palsies are far more common than femoral palsies (66; 20). A review of the literature, however, reports an incidence rate ranging from 0.1% to 2.4% following primary total hip arthroplasty (mean 0.8%) and 0.3% to 2.3% following revision total hip arthroplasty (mean 1.1%) (21).

Mononeuropathies after hip surgery are usually caused by stretch injury, but at times, may be due to encasement and damage by the cementing substance used. In one case, acetabular reinforcement rings loosened leading to intrapelvic granuloma formation and subsequent femoral nerve compression (06). Femoral neuropathy can also result from the placement of anterior acetabular retractors over the femoral nerve (79). Risk factors for the occurrence of any motor nerve palsy after hip arthroplasty may include developmental dysplasia of the hip, revision surgery, posttraumatic arthritis, surgical lengthening of a leg, cement-less femoral fixation, and a posterior surgical approach (20; 66). Neurologists should also be mindful of the surgical approach used when evaluating cases of suspected femoral mononeuropathy. The direct anterior approach to hip replacement is muscle-sparing and typically offers faster recovery and less postoperative pain. A series of 1756 patients undergoing a direct anterior approach total hip arthroplasty had a low femoral neuropathy incidence of 0.34% (57). In these cases, the authors speculated that the presence of large, anterior osteophytes may have contributed to the risk of femoral nerve injury due to difficulty placing an anterior retractor on the wall of the anterior acetabulum.

Although 77% of orthopedic surgery–associated femoral neuropathies are from hip procedures (total hip arthroplasty or revision), knee surgeries can also be complicated by femoral nerve injury, particularly total knee arthroplasty. There have also been demonstrated cases of femoral neuropathy from lateral knee release and tibial tubercle osteotomy (64).

Femoral neuropathy due to operative positioning. The femoral nerve may become compressed at the inguinal ligament during lithotomy positioning for various procedures, such as vaginal delivery, urological and rectal procedures, vaginal hysterectomy, and laparoscopy (77; 02; 26). In a single-center retrospective review, the femoral nerve was the most commonly injured nerve following gynecological surgery (23 total cases among 2449 reviewed surgeries) (16). Women of thin habitus and smokers are at higher risk of lithotomy-induced femoral neuropathy (69). Prolonged lithotomy positioning due to immobility after drug overdose has also been reported to cause femoral neuropathy (74). Femoral neuropathy can also occur after prolonged hyperlordotic positioning. A case has been reported in which femoral neuropathy occurred after a prolonged dental procedure (04). The patient was placed in a hyperlordotic position to improve surgical exposure and the field of view of the surgeon.

Local compression. The vast majority of nonperioperative femoral neuropathies are due to local compression. Nerve injury occurs most commonly in the setting of retroperitoneal hematomas, but masses, abscesses, vascular catheterization, and radiation are other established causes (64).

Femoral neuropathy due to iliacus or iliopsoas hematoma. Acute retroperitoneal hemorrhage within the iliacus muscle, or less commonly the psoas muscle, can lead to a compartment syndrome, which may result in femoral nerve injury (85; 59; 81). Hematoma formation may occur after trauma, but these often occur spontaneously, typically in patients receiving anticoagulation therapy. This is a relatively common etiology of femoral neuropathy, as hematomas are estimated to cause about 21% of femoral neuropathy cases (64).

Up to 10% of patients with hemophilia may experience iliopsoas bleeding, with estimates of the proportion of these patients developing femoral neuropathy ranging from 39.3% to 57% (07; 55). Rarely, anticoagulant therapy can lead to bilateral thigh hematomas within the iliopsoas muscle and result in bilateral femoral nerve palsy (25; 78; 42; 80). Low molecular weight heparin infusions may yield similar hematomas with compression (35). Less commonly, the hematoma extends into the retroperitoneal space, leading to a more extensive injury of the lumbar plexus or entire lumbosacral plexus (33).

Femoral neuropathy due to other local compression. Inguinal lymphadenopathies, femoral vessel catheterization or cannulation, and localized hematomas rarely can cause femoral neuropathy. ECMO may be particularly likely to injure the femoral nerve. In a systematic review, 7.9% of patients with femoral ECMO cannulation developed femoral nerve injury, thought to be compressive either from the large cannula or swelling or hematoma in the surrounding tissue (30). Rheumatoid arthritis has been described to cause iliopsoas bursitis and iliopectineal synovitis, with this inflammation leading to femoral nerve entrapment (44; 72; 73; 51). Large renal cysts, as can occur in polycystic kidney disease, may rarely affect femoral nerve function (84). Infection from taenia echinococcus leading to hydatid cyst formation in the psoas muscle with femoral nerve compression has also been reported (28), as have other retroperitoneal abscesses (64). Likewise, benign and malignant tumors can cause compression femoral neuropathies (64).

Radiation (46), and laceration, misplaced injection and tourniquet application (39; 64) are extremely rare causes of femoral nerve injury. Patellar dislocation has been rarely identified as a cause of femoral nerve injury more proximally at the level of the inguinal ligament (75).

Pseudoaneurysm formation can rarely complicate femoral artery access for endovascular procedures (23). Qureshi and colleagues reviewed 270 neuroendovascular procedures and found that four of their patients reported symptoms of femoral neuropathy that were typically transient and sensory predominant (61).

Inflammatory. Inflammatory femoral neuropathies comprise approximately 10% of all cases, with the other 90% being local compression/stretch/injury. As these cases are relatively rare, the relative proportion of etiologies hasn’t been clearly established. In a large case series of 10 patients with inflammatory femoral neuropathy, four were due to diabetic inflammatory mononeuropathy, two to focal CIDP, one to vasculitis, one was postviral, one was postsurgical, and one was idiopathic. These patients typically presented with subacute pain followed by weakness in the femoral nerve distribution, although one patient’s presentation was painless (64).

Table 1. Common Causes of Femoral Neuropathy

Compression in pelvis
	• During pelvic surgery by retractor blade (stretch and/or direct compression)
		- abdominal hysterectomy - radical prostatectomy - renal transplantation (60; 76) - colectomy - proctectomy - nephrectomy (34) - laparoscopic hernia repair (05) - vascular bypass surgery (05) - renal transplantation (11)
	• By iliacus or psoas retroperitoneal hematoma
		- anticoagulation - hemophilia (07) - coagulopathy - ruptured abdominal aneurysm - femoral artery catheterization - spontaneous hematoma formation (17)
	• By pelvic mass
		- lymphadenopathy - tumor - abscess - extrapelvic synovial cyst (70) - aortic or iliac aneurysm
	• By iliopsoas inflammation
		- rheumatoid arthritis causing iliopsoas bursitis (44)
Compression at the inguinal ligament
	• During lithotomy position by inguinal ligament
		- vaginal delivery - laparoscopy - vaginal hysterectomy - urological and rectal procedures - due to drug overdose (74)
	• By inguinal hematoma
		- femoral artery catheterization (05) - angiography - pseudoaneurysm originating from the left iliolumbar artery (62)
	• During total hip replacement (79) • Pavlik harness treatment for hip developmental dysplasia (50) • Psoas compartment block (03) • Tourniquet palsy • Following decannulation from venoarterial extracorporeal membrane oxygenation therapy (27) • By inguinal mass (eg, lymphadenopathy)
Miscellaneous
	• Inflammatory (64) • Radiation, misplaced injection, laceration • Traumatic injury following nerve block (19) • Gunshot or crush injury (64) • “Hanging leg syndrome” reported in an intoxicated male who lay supine with both legs hanging over the end of his bed with hips hyperextended, leading to combined bilateral femoral and sciatic neuropathies (65) • Patellar dislocation in dancers (68) • Myofibroblastic sarcoma infiltration (71) • Football (soccer) trauma (17) • Trampolining injury (14) • Bilateral femoral neuropathies with rhabdomyolysis (63; 53) • Small risk of femoral neuropathy after nerve block (12) • Prolonged hyperlordotic position with thigh hyperextension following a suicide attempt (43)

In order to understand the pathophysiology of femoral neuropathy, it is essential to review the anatomy of the femoral nerve, which is also called the anterior crural nerve. The nerve is formed when the posterior divisions of the ventral rami of L2, L3, and L4 spinal roots combine. Note that the anterior divisions of the same roots form the obturator nerve. Once formed, the femoral nerve immediately gives branches to the psoas muscle before it enters its substance. Then, covered by a tight iliac fascia, the femoral nerve passes between the psoas and iliacus muscles where it innervates the latter. After passing underneath the rigid inguinal ligament, the femoral nerve branches widen into its terminal motor branches (to the quadriceps and sartorius) and sensory branches (to the anterior thigh), including the saphenous sensory nerve, which innervates the skin over the medial half of the leg to the ankle. Experimental evidence shows that nerve injury occurs if the nerve is elongated by more than 6% of its original length; hence, females with shorter nerves are more prone to injuries with the use of retractors (21).

Femoral nerve anatomy

The femoral nerve and its terminal motor and sensory branches including the saphenous nerve. (Used with permission, Haymaker W, Woodhall B. Peripheral nerve injuries: principles of diagnosis. Philadelphia: W.B. Saunders, 1953.)

The primary pathological process in femoral neuropathy is either demyelinating or axonal. This determines the prognosis for recovery.

Differential diagnosis

Confusing conditions

The most important alternative considerations in the differential diagnosis are lumbosacral radiculopathy and lumbosacral plexopathy. The hip flexors and quadriceps are innervated by the L2-L4 nerve roots, so radiculopathy at these levels or damage to the upper lumbar plexus could cause similar symptoms to a femoral neuropathy. Diabetic lumbosacral radiculoplexus neuropathy (also known as diabetic amyotrophy) is an especially relevant cause of lumbosacral plexopathy to consider as it commonly presents with severe thigh pain, weakness, and atrophy.

Three important clinical features are useful at the bedside:

(1) Weakness of thigh adductors, innervated by the obturator nerve, excludes a selective femoral lesion. When present, this suggests radiculopathy or plexopathy.

(2) A positive straight-leg test is nonspecific. It is common in lumbar radiculopathy; however, it may occur with lumbar plexopathy and femoral nerve lesion, particularly when due to retroperitoneal hematoma.

(3) In plexopathy or radiculopathy, weakness of ankle dorsiflexion is common and does not occur in femoral nerve lesions. Likewise, reduced or absent Achilles reflex does not occur with femoral neuropathy and should, therefore, raise consideration of plexopathy or multilevel radiculopathy.

Associated or underlying disorders

This article relates primarily to femoral mononeuropathy. Careful neurologic examination should be undertaken to exclude the presence of additional mononeuropathies elsewhere—mononeuropathy multiplex. Unless there is an obvious cause (eg, trauma, compression), this presentation should raise concern for vasculitic neuropathy. Hereditary neuropathy with liability to pressure palsies can also present with mononeuropathy multiplex.

Diagnostic workup

A thorough neurologic examination is critical for recognizing femoral neuropathy and distinguishing it from mimicking conditions. Knee extension weakness is expected, and hip flexion may be weak if the lesion is proximal to the inguinal ligament. Hip adduction, innervated by the obturator nerve, should be examined to help exclude mimics. Of note, severe pain may lead to limitation of movement separate from neurologic weakness and can be recognized by a “give-way” pattern on examination. Sensory examination may detect a deficit over the anteromedial thigh and medial leg. The patellar reflex is diminished or absent in femoral neuropathy.

Apart from urgent CT or MRI of the pelvis in patients with suspected retroperitoneal hemorrhage, EMG examination, including detailed nerve conduction studies and needle EMG, is frequently employed for diagnostic and prognostic purposes.

Table 2. EMG Diagnostic Strategy

	Femoral neuropathy	Lumbar plexopathy	Lumbar radiculopathy
Saphenous SNAP†	Low or absent	Low or absent	Normal
EMG findings of thigh adductors	Normal	Denervation‡	Denervation‡
EMG findings of tibialis anterior	Normal	Denervation‡	Denervation‡
EMG findings of paraspinal muscles	Normal	Normal (except some cases of diabetic amyotrophy)	Fibrillation and positive sharp waves may be seen after approximately 2 weeks

Nerve conduction studies can be performed to examine the femoral nerve compound motor action potential recording over rectus femoris, with stimulation placed at the groin. A low-amplitude femoral compound muscle action potential is seen with axonal injury to the femoral nerve. The sensory nerve action potential of the saphenous nerve is useful for localization. This will be of low amplitude or absent in femoral neuropathy and (usually) lumbar plexopathies but is normal in radiculopathy. Both femoral compound muscle action potentials and saphenous sensory nerve action potentials can be technically difficult to obtain, even in normal individuals, so comparison with the asymptomatic side is always advised. Needle EMG is often most useful for localization to the femoral nerve and exclusion of mimics. Needle EMG abnormalities of the thigh adductors, for example, exclude femoral mononeuropathy and would suggest either plexopathy or radiculopathy. Likewise, fibrillation potentials and positive sharp waves seen in the lumbar paraspinal muscles are seen with involvement of the nerve root, thus, suggesting a lumbosacral radiculopathy.

MR neurography (MRN) for femoral neuropathy may be useful if electrophysiologic studies are equivocal or if an etiology for femoral neuropathy is not obvious from prior workup. Advantages of MRN are that benign and malignant peripheral nerve sheath tumors can be delineated and characterized further by MR imaging (13) and potentially lead to a site-directed biopsy to determine pathological diagnosis.

The utility of ultrasound in assessment of traumatic peripheral nerve lesions is increasing. High-resolution ultrasound can be used for anatomic understanding and surgical planning of femoral neuropathy. Zeidenberg and colleagues presented a case of femoral neuropathy in a patient developing pseudoaneurysm after undergoing a procedure for cardiac ablation via percutaneous femoral artery approach (86). Ultrasound was performed the same day to evaluate the patient and it showed a pseudoaneurysm dissecting and displacing the left femoral nerve. Surgery for vascular repair and neurolysis of the left femoral nerve with sural nerve grafting was performed.

Management

Most patients with femoral neuropathy are managed conservatively. A knee brace may be useful if there is significant knee extension weakness. Physical therapy may help the patient avoid falls and aid in restrengthening the affected muscles. A case report suggests early involvement of rehabilitation medicine (PM& R) may be helpful in patients with significant weakness (47). If pain is significant, neuropathic pain or anti-inflammatory medications may be trialed. A knee-ankle-foot orthosis is helpful for patients with severe weakness of the quadriceps so as to prevent falls. A case report indicates that percutaneous femoral nerve stimulation can ameliorate intractable causalgic pain (52). In a small case series, femoral nerve palsy due to traumatic or other causes may also benefit from femoral neurolysis (19), but this method is unproven. In cases where recovery was poor and weakness persists, nerve transfer has been tried to improve knee extension function (45; 58; 83).

Controversy exists regarding the indication and timing of surgical evacuation of hematoma if a compressive femoral nerve lesion is clinically apparent. In theory, surgical evacuation should occur as soon as possible, even before signs of severe femoral nerve injury and axonal degeneration occur (56; 18). Practically, limited data on the natural history of hematomas are available; therefore, decisions regarding surgical management are often made on a case-by-case basis. Good outcomes have been reported with both conservative and early surgical management. Therefore, factors for consideration include severity of femoral neuropathy, surgical risk, size of hematoma, hemodynamic stability, degree of axonal loss on electrophysiology (based on side-to-side comparison of femoral motor compound muscle action potential), and etiology, with very severe weakness and progression of weakness most frequently advocated for as indications for surgical drainage (59; 38).

References

01: Abel NA, Januszewski J, Vivas AC, Uribe JS. Femoral nerve and lumbar plexus injury after minimally invasive lateral retroperitoneal transposas approach: electrodiagnostic prognostic indicators and a roadmap to recovery. Neurosurg Rev 2018;41(2):457-64. PMID 28560607
02: Al Hakim M, Katirji MB. Femoral mononeuropathy induced by the lithotomy position: a report of 5 cases and a review of the literature. Muscle Nerve 1993;16:891-5. PMID 8355719
03: Al-Nasser B, Palacios JL. Femoral nerve injury complicating continuous psoas compartment block. Reg Anesth Pain Med 2004;29(4):361-3. PMID 15305257
04: Albrecht P, Grosse J, Neukaeter W. Femoral neuropathy caused by hyperlordotic positioning. J Anesth 2014;28(5):800. PMID 24554248
05: Azuelos A, Coro L, Alexandre A. Femoral nerve entrapment. Acta Neurochir Suppl 2005;92:61-2. PMID 15830969
06: Bader R, Mittelmeier W, Zeiler G, Tokar I, Steinhauser E, Schuh A. Pitfalls in the use of acetabular reinforcement rings in total hip revision. Arch Orthop Trauma Surg 2005;125(8):558-63. PMID 16189686
07: Balkan C, Kavakli K, Karapinar D. Iliopsoas haemorrhage in patients with haemophilia: results from one centre. Haemophilia 2005;11(5):463-7. PMID 16128889
08: Bohrer JC, Walters MD, Park A, Polston D, Barber MD. Pelvic nerve injury following gynecologic surgery: a prospective cohort study. Am J Obstet Gynecol 2009;201(5):531-7. PMID 19761997
09: Bradshaw AD, Advincula AP. Postoperative neuropathy in gynecologic surgery. Obstet Gynecol Clin North Am 2010;37(3):451-9. PMID 20674786
10: Brasch RC, Bufo AJ, Kreienberg PF, Johnson GP. Femoral neuropathy secondary to the use of a self-retaining retractor. Report of three cases and review of the literature. Dis Colon Rectum 1995;38:1115-8. PMID 7555431
11: Brouns R, De Deyn PP. Neurological complications in renal failure: a review. Clin Neurol Neurosurg 2004;107(1):1-16. PMID 15567546
12: Brull R, McCartney CJ, Chan VW, El-Beheiry H. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesth Analg 2007;104(4):965-74. PMID 17377115
13: Chhabra A, Faridian-Aragh N. High-resolution 3-T MR neurography of femoral neuropathy. AJR Am J Roentgenol 2012;198(1):3-10. PMID 22194473
14: Chambers S, Berg AJ, Lupu A, Jennings A. Iliacus haematoma causing femoral nerve palsy: an unusual trampolining injury. BMJ Case Rep 2015;2015. PMID 26216923
15: Chaudhry V, Cornblath DR. Wallerian degeneration in human nerves: serial electrophysiologic studies. Muscle Nerve 1992;15:687-93. PMID 1324426
16: Chen E, Kowalski JT. Natural history of postoperative neuropathies in gynecologic surgery. Int Urogynecol J 2022;33(9):2471-4. PMID 35384477
17: Cingel V, Kokavec M, Trnka J. [Paresis of the femoral nerve in pelvic extraperitoneal hematoma--case reports and literature review]. [Article in Slovak]. Acta Chir Orthop Traumatol Cech 2005;72(4):250-3. PMID 16194445
18: Crawford AM, Guild TT, Striano BM, Von Keudell AG. Spontaneous iliacus haematoma with femoral nerve palsy: an appeal to involve surgical teams early. BMJ Case Rep 2021;14(1):e239024. PMID 33462039
19: Ducic I, Dellon L, Larson EE. Treatment concepts for idiopathic and iatrogenic femoral nerve mononeuropathy. Ann Plast Surg 2005;55(4):397-401. PMID 16186707
20: Farrell CM, Springer BD, Haidukewych GJ, Morrey BF. Motor nerve palsy following primary total hip arthroplasty. J Bone Joint Surg Am 2005;87(12):2619-25. PMID 16322610
21: Fox AJ, Bedi A, Wanivenhaus F, Sculco TP, Fox JS. Femoral neuropathy following total hip arthroplasty: review and management guidelines. Acta Orthop Belg 2012;78(2):145-51. PMID 22696981
22: Goldman JA, Feldberg D, Dicker D, Samuel N, Dekel A. Femoral neuropathy subsequent to abdominal hysterectomy. A comparative study. Eur J Obstet Gynecol Reprod Biol 1985;20:385-92. PMID 3002881
23: Gooneratne T, Wijeyaratne M. Iatrogenic deep femoral artery pseudoaneurysm causing quadriceps paralysis: an indication for open surgery in an endovascular era. Vasc Specialist Int 2021;37:25. PMID 34349045
24: Hesse D, Kandmir U, Solberg B, et al. Femoral nerve palsy after pelvic fracture treated with INFIX: a case series. J Orthop Trauma 2015;29(3):138-43.** PMID 24983430
25: Ho KJ, Gawley SD, Young MR. Psoas haematoma and femoral neuropathy associated with enoxaparin therapy. Int J Clin Pract 2003;57(6):553-4. PMID 12918901
26: Hsieh LF, Liaw ES, Cheng HY, Hong CZ. Bilateral femoral neuropathy after vaginal hysterectomy. Arch Phys Med Rehabil 1998;79(8):1018-21. PMID 9710179
27: Jang AY, Oh YJ, Lee SI, Lim OK, Suh SY. Femoral neuropathy following venoarterial-extracorporeal membrane oxygenation therapy: a case report. BMC Cardiovasc Disord 2020;20(1):393. PMID 32854617
28: Jellad A, Boudokhane S, Ezzine S, Ben Salah Z, Golli M. Femoral neuropathy caused by compressive iliopsoas hydatid cyst: a case report and review of the literature. Joint Bone Spine 2010;77(4):371-2. PMID 20478731
29: Jog MS, Turley JE, Berry H. Femoral neuropathy in renal transplantation. Can J Neurol Sci 1994;21:38-42. PMID 8180903
30: Johannes F, Frohofer-Vollenweider R, Teuschi Y. Neurological complications of the lower extremities after femoral cannulated extracorporeal membrane oxygenation: a systematic review. J Intensive Care Med 2023. [Epub ahead of print] PMID 38018080
31: Katirji B. Compressive and entrapment neuropathies of the lower extremity. In Katirji B, Kaminski HJ, Preston DC, et al, editors. Neuromuscular Disorders in Clinical Practice. Boston: Butterworth Heinmann, 2002:774.
32: Katirji MB, Lanska DJ. Femoral mononeuropathy after radical prostatectomy. Urology 1990;36:539-40. PMID 2247926
33: Kent KC, Moscucci M, Gallagher SG, DiMattia ST, Skillman JJ. Neuropathy after cardiac catheterization: incidence, clinical patterns, and long-term outcome. J Vasc Surg 1994;19:1008-13. PMID 8201701
34: Kesikburun B, Ekşioğlu E, Akyüz EÜ, Demirel F, Çakcı A. Femoral nerve injury after nephrectomy: a case report. J Back Musculoskelet Rehabil 2015;28(4):873-5. PMID 25408120
35: Khanna V, Ashraf M, Sambandan SN. Spontaneous retroperitoneal hematoma presenting as femoral neuropathy in a patient on low molecular weight heparin therapy. J Orthop Case Rep 2018;8(3):55-7. PMID 30584517
36: Kim DH, Murovic JA, Tiel RL, Kline DG. Intrapelvic and thigh-level femoral nerve lesions: management and outcomes in 119 surgically treated cases. J Neurosurg 2004;100(6):989-96. PMID 15200113
37: Kim MH, Jun KW, Hwang JK, Moon IS, Kim JI. Characteristics of femoral motor neuropathies induced after kidney transplantation: a case series. Transplant Proc 2016;48(3):933-7. PMID 27234771
38: Kim SJ, Park HS, Lee DW. Iliacus hematoma syndrome: a systematic review of recent literature and case report. Injury 2020;51(8):1744-50. PMID 32487330
39: Kornbluth ID, Freedman MK, Sher L, Frederick RW. Femoral, saphenous nerve palsy after tourniquet use: a case report. Arch Phys Med Rehabil 2003;84(6):909-11. PMID 12808548
40: Kuntzer T, Van Melle G, Regli F. Clinical and prognostic features of femoral neuropathies. Muscle Nerve 1997;20:205-11. PMID 9040660
41: Kvist-Poulsen H, Borel J. Iatrogenic femoral neuropathy subsequent to abdominal hysterectomy: incidence and prevention. Obstet Gynecol 1982;60:516-20. PMID 7121938
42: Macauley P, Soni P, Akkad I, Demir S, Shankar S, Kakar P, Bhardwaj S. Bilateral femoral neuropathy following psoas muscle hematomas caused by enoxaparin therapy. Am J Case Rep 2017;18:937-40. PMID 28848224
43: Mathis S, du Boisgueheneuc F, Godenche G, Ansquer S, Neau J. Bilateral femoral neuropathy after massive toxic ingestion in a suicide attempt. Neurologist 2012;18(2):70-2. PMID 22367832
44: Matsumoto T, Juji T, Mori T. Enlarged psoas muscle and iliopsoas bursitis associated with a rapidly destructive hip in a patient with rheumatoid arthritis. Mod Rheumatol 2006;16(1):52-4. PMID 16622726
45: McInnes CW, Ha AY, Power HA, Tung TH, Moore AM. Femoral nerve decompression and sartorius-to-quadriceps nerve transfers for partial femoral nerve injury: a cadaveric study and early case series. J Neurosurg 2020:1-8. PMID 33157531
46: Mendes DG, Nawalkar RR, Eldar S. Post-irradiation femoral neuropathy. A case report. J Bone Joint Surg Am 1991;73:137-40. PMID 1985985
47: Moita Goncalves E, Lanzaro C, Silva LC, et al. Enhancing functional recovery following postpartum femoral neuropathy: early neurorehabilitation and multidisciplinary obstetric care. Int J Gynecol Obstet 2024;164(3):830-4. PMID 37537869
48: Moore AE, Stringer MD. Iatrogenic femoral nerve injury: a systematic review. Surg Radiol Anat 2011;33(8):649-58. PMID 21328076
49: Muller C, van Houwelingen EE, Huygen F. Femoral neuropathy following a psoas hitch vesicopexy. BMJ Case Rep 2018;2018. PMID 30049676
50: Murnaghan ML, Browne RH, Sucato DJ, Birch J. Femoral nerve palsy in Pavlik harness treatment for developmental dysplasia of the hip. J Bone Joint Surg Am 2011;93(5):493-9. PMID 21368082
51: Murphy CL, Meaney JF, Rana H, McCarthy EM, Howard D, Cunnane G. Giant iliopsoas bursitis: a complication of chronic arthritis. J Clin Rheumatol 2010;16(2):83-5. PMID 20216129
52: Narouze SN, Zakari A, Vydyanathan A. Ultrasound-guided placement of a permanent percutaneous femoral nerve stimulator leads for the treatment of intractable femoral neuropathy. Pain Physician 2009;12(4):E305-8. PMID 19668289
53: Ng YS, Li HS, Chan CW. Bilateral femoral nerve compression and compartment syndrome resulting from influenza A-induced rhabdomyolysis: a case report. J Orthop Surg (Hong Kong) 2008;16(1):117-21. PMID 18453675
54: O'Neal MA, Chang LY, Salajegheh MK. Postpartum spinal cord, root, plexus and peripheral nerve injuries involving the lower extremities: a practical approach. Anesth Analg 2015;120(1):141-8. PMID 25625259
55: Panuwannakorn M, Jiravichitchai T, Lertthammakiat S, Jaovisidha S, Sirachainan N, Chuansumrit A. Iliopsoas haemorrhage complicated by femoral neuropathy in patients with haemophilia: a case series report. Int J Hematol 2023;117(2):293-306. PMID 36151351
56: Parmer SS, Carpenter JP, Fairman RM, Velazquez OC, Mitchell ME. Femoral neuropathy following retroperitoneal hemorrhage: case series and review of the literature. Ann Vasc Surg 2006;20(4):536-40. PMID 16741653
57: Patton RS, Runner RP, Lazarus D, Bradbury TL. Femoral neuropathy following direct anterior total hip arthroplasty: an anatomic review and case series. J Surg Case Rep 2018;2018(9):rjy171. PMID 30206472
58: Peters BR, Ha AY, Moore AM, Tung TH. Nerve transfers for femoral nerve palsy: an updated approach and surgical technique. J Neurosurg 2021;136(3):856-66. PMID 34416726
59: Pirouzmand F, Midha R. Subacute femoral compressive neuropathy from iliacus compartment hematoma. Can J Neurol Sci 2001;28(2):155-8. PMID 11383942
60: Ponticelli C, Campise MR. Neurological complications in kidney transplant recipients. J Nephrol 2005;18(5):521-8. PMID 16299677
61: Qureshi AI, Babar S, Kherani D, et al. Femoral neuropathy following transfemoral neuroendovascular procedures. J Neuroimaging 2019;29(2):268-71. PMID 30468262
62: Rochman AS, Vitarbo E, Levi AD. Femoral nerve palsy secondary to traumatic pseudoaneurysm and iliacus hematoma. J Neurosurg 2005;102(2):382-5. PMID 15739570
63: Roth JV. Bilateral sciatic and femoral neuropathies, rhabdomyolysis, and acute renal failure caused by positioning during radical retropubic prostatectomy. Anesth Analg 2007;105(6):1747-8. PMID 18042878
64: Santilli AR, Martinez-Thompson JM, Speelziek SJA, Staff NP, Laughlin RS. Femoral neuropathy: a clinical and electrodiagnostic review. Muscle Nerve 2024;69(1):64‐71. PMID 37941415
65: Scherer K, Skeen MB, Strine SA, Juel VC. Hanging leg syndrome: combined bilateral femoral and sciatic neuropathies. Neurology 2006;66(7):1124-5. PMID 16606938
66: Schmalzried TP, Amstutz HC, Dorey FJ. Nerve palsy associated with total hip replacement. Risk factors and prognosis. J Bone Joint Surg Am 1991;73(7):1074-80. PMID 1874771
67: Sharma KR, Cross J, Santiago F, Ayyar DR, Burke G 3rd. Incidence of acute femoral neuropathy following renal transplantation. Arch Neurol 2002;59:541-5. PMID 11939888
68: Shin CS, Davis BA. Femoral neuropathy due to patellar dislocation in a theatrical and jazz dancer: a case report. Arch Phys Med Rehabil 2005;86(6):1258-60. PMID 15954069
69: Stewart J. Focal peripheral neuropathies. 3rd edition. Philadelphia: Lippincott Williams and Wilkins, 2000;431.
70: Stuplich M, Hottinger AF, Stoupis C, Sturzenegger M. Combined femoral and obturator neuropathy caused by synovial cyst of the hip. Muscle Nerve 2005;32(4):552-4. PMID 15948204
71: Tajima Y, Sudoh K, Matsumoto A, Kikuchi S, Sasaki H. Femoral neuropathy induced by a low-grade myofibroblastic sarcoma of the groin. J Neurol 2005;252(11):1416-7. PMID 15981081
72: Tatsumura M, Mishima H, Shiina I, et al. Femoral nerve palsy caused by a huge iliopectineal synovitis extending to the iliac fossa in a rheumatoid arthritis case. Mod Rheumatol 2008;18(1):81-5. PMID 18180875
73: Tokita A, Ikari K, Tsukahara S, et al. Iliopsoas bursitis-associated femoral neuropathy exacerbated after internal fixation of an intertrochanteric hip fracture in rheumatoid arthritis: a case report. Mod Rheumatol 2008;18(4):394-8. PMID 18421416
74: Tsiptsios D, Daud D, Tsamakis K, Rizos E, Anastadiadis A, Cassidy A. Bilateral femoral neuropathy: a rare complication of drug overdose due to prolonged posturing in lithotomy position. Case Rep Neurol Med 2020;2020:2352850. PMID 32231823
75: Tuck JA, Meads SM, Ramage JL. Femoral nerve palsy with concomitant patellar dislocation in a ballet dancer. Orthopedics 2018:1-3. PMID 30540875
76: Van Veer H, Coosemans W, Pirenne J, Monbaliu D. Acute femoral neuropathy: a rare complication after renal transplantation. Transplant Proc 2010;42(10):4384-8. PMID 21168704
77: Vargo MM, Robinson LR, Nicholas JJ, Rulin MC. Postpartum femoral neuropathy: relic of an earlier era. Arch Phys Med Rehabil 1990;71:591-6. PMID 2369297
78: Wada Y, Yanagihara C, Nishimura Y. Bilateral iliopsoas hematomas complicating anticoagulant therapy. Intern Med 2005;44(6):641-3. PMID 16020897
79: Weber ER, Daube JR, Coventry MB. Peripheral neuropathies associated with total hip arthroplasty. J Bone Joint Surg Am 1976;58(1):66-9. PMID 175071
80: White DJ, Lytle FT. Femoral neuropathy following spontaneous retroperitoneal hemorrhage after cardiac surgery: a case report. A A Case Rep 2017;8(8):203-5. PMID 28079661
81: Won DY, Kim SD, Park SC, Moon IS, Kim JI. Abdominal compartment syndrome due to spontaneous retroperitoneal hemorrhage in a patient undergoing anticoagulation. Yonsei Med J 2011;52(2):358-61. PMID 21319359
82: Wong CA. Nerve injuries after neuraxial anaesthesia and their medicolegal implications. Best Pract Res Clinical Obstet and Gynaecol 2010;24(3):367-81. PMID 20053587
83: Wu KP, Lin LC, Lu JC. Application of supercharge end-to-side (SETS) obturator to femoral nerve transfer in electrical injury-induced neuropathy to improve knee extension. Arch Plast Surg 2022;49(6):769-72. PMID 36523909
84: Yoo J, Lim KB, Lee HJ, Kim J, You EC, Kang J. Femoral neuropathy secondary to autosomal dominant polycystic kidney disease: a case report. Ann Rehabil Med 2018;42(3):488-93. PMID 29961749
85: Young MR, Norris JW. Femoral neuropathy during anticoagulant therapy. Neurology 1976;26:1173-5. PMID 1033486
86: Zeidenberg J, Burks SS, Jose J, Subhawong TK, Levi AD. The utility of ultrasound in the assessment of traumatic peripheral nerve lesions: report of 4 cases. Neurosurg Focus 2015;39(3):E3. PMID 26323821

Contributors

All contributors' financial relationships have been reviewed and mitigated to ensure that this and every other article is free from commercial bias.

Authors

Christopher Doughty MD

Dr. Doughty of Brigham and Women's Hospital received an honorarium from UCB as a Scientific Advisory Board member, clinical trial funding from AstraZeneca as a co-investigator, an honorarium from TD Cowen as a panel speaker, and a consulting fee from Neurometrix.
See Profile
Sarah Smith MD PhD

Dr. Smith of Brigham and Women's Hospital has no relevant financial relationships to disclose.
See Profile

Editor

Randolph W Evans MD

Dr. Evans of Baylor College of Medicine received honorariums from Abbvie, Amgen, Biohaven, Impel, Lilly, and Teva for speaking engagements.
See Profile

Former Authors

Ryan Jacobson MD
Bashar Katirji MD (original author), Cory Toth MD BSc, Syeda Maria Muzammil, Sameera Salman Ghauri MBBS, Thy Nguyen MD, and Kazim Sheikh MD

Patient Profile

Age range of presentation: All ages
Sex preponderance: No information is available
Heredity: none
Population groups selectively affected: none selectively affected
Occupation groups selectively affected: none selectively affected

This is an article preview.
Start a Free Account
to access the full version.

Nearly 3,000 illustrations, including video clips of neurologic disorders.
Every article is reviewed by our esteemed Editorial Board for accuracy and currency.
Full spectrum of neurology in 1,200 comprehensive articles.
Listen to MedLink on the go with Audio versions of each article.

Questions or Comment?

MedLink®, LLC

3525 Del Mar Heights Rd, Ste 304
San Diego, CA 92130-2122

Toll Free (U.S. + Canada): 800-452-2400

US Number: +1-619-640-4660

Support: service@medlink.com

Editor: editor@medlink.com

ISSN: 2831-9125

Femoral neuropathy

Differential Diagnosis

lumbosacral radiculopathy
lumbar plexopathy
diabetic lumbosacral radiculoplexus neuropathy
diabetic amyotrophy
quadriceps tendon tear
- mononeuropathy multiplex

Also Relevant

Cardiac catheterization: neurologic complications
Hemophilia and other coagulation disorders: neurologic aspects
Lumbar disc disease
Lumbosacral plexus injuries
Peroneal neuropathy
- Pregnancy: neuromuscular complications
- Sciatic neuropathy
- Sports activities: neurologic complications

Clinical Categories

Patient Handouts

Pinched nerve

	• 0.1% to 2.4% following primary total hip arthroplasty (21)
	• 2.5% following Pavlik harness treatment for developmental dysplasia of the hip (50).
	• 0.14% to 2.2% following renal transplantation (67; 76).
	• 0.1% following femoral artery cannulation for cardiac catheterization (33). The prevalence of retroperitoneal hemorrhage is about 0.5%, and about one-third of these hemorrhages result in femoral nerve injury or a lumbar plexopathy. A more contemporary case series of neurovascular procedures utilizing femoral artery access demonstrated four femoral nerve palsies out of 270 cases (1.5%), but all four had only sensory loss without any motor weakness (61).
	• 2.8 of 100,000 deliveries during lithotomy positioning for vaginal delivery. This is likely underestimated, representing only patients with severe femoral nerve lesions necessitating neurologic consultations (77). Prospective studies suggest the incidence is closer to 1% (82).

Femoral neuropathy

Introduction

Overview

Key points

Historical note and terminology

Clinical manifestations

Presentation and course

Prognosis and complications

Clinical vignette

Biological basis

Etiology and pathogenesis

Table 1. Common Causes of Femoral Neuropathy

Epidemiology

Prevention

Differential diagnosis

Confusing conditions

Associated or underlying disorders

Diagnostic workup

Table 2. EMG Diagnostic Strategy

Management

Special considerations

Pregnancy

Anesthesia

Media

References

Contributors

Authors

Editor

Former Authors

Patient Profile

ICD & OMIM codes

This is an article preview. Start a Free Account to access the full version.

Questions or Comment?

Also in This Category

NF2-related schwannomatosis

Familial dysautonomia

Neurogenetics and genetic and genomic testing

Acute traumatic spinal cord injury

Tumors of the skull base

Primary headache associated with sexual activity

Peripheral nerve complications of HIV-1 infection

Toxic and nutritional deficiency optic neuropathies

This is an article preview.
Start a Free Account
to access the full version.