Injuries to the lateral femoral cutaneous nerve during spine surgery

STUDY DESIGN: A prospective study to locate patients with injured lateral femoral cutaneous nerve after elective spine surgery. OBJECTIVES: To assess the prevalence of injury of the lateral femoral cutaneous nerve and to identify the cause of injury according to the position of the patients at surgery and the surgical approach. SUMMARY OF BACKGROUND DATA: Injuries to the lateral femoral cutaneous nerve, also known as meralgia paresthetica, may cause pain and therefore result in restriction of activity. Compression of the nerve by disc hernia, retroperitoneal tumors, and external pressure around the anterior superior iliac spine are among the more common causes. METHODS: One hundred five patients admitted for elective spine procedures were grouped according to position on the operating table and surgical approach. All patients were examined before and after surgery for signs of injury to the lateral femoral cutaneous nerve, and those found injured were followed up for 1 year after surgery. RESULTS: Injury to the lateral femoral cutaneous nerve was found in 21 (20%) patients. In 6 of them, all of whom underwent surgery on the Hall-Relton frame, the injury was bilateral. In 7 patients the injury was not associated with discomfort. In addition to injury by external pressure at the anterior superior iliac spine from the Hall-Relton frame, the nerve was also injured at the retroperitoneum by hematoma or traction and at the anterior iliac crest when bone was harvested. In 89% of the patients, the nerve completely recovered within 3 months of surgery. Two patients still had pain 1 year after surgery and hypoesthesia of the anterolateral thigh. CONCLUSION: Injuries to the lateral femoral cutaneous nerve during spine surgery are frequent, and patients should be informed of the possible risk. It usually has a benign course, but some preventive steps should be taken: keep posterior to the anterior superior iliac spine and minimize retraction when harvesting a bone graft, pad the posts of the Hall-Relton frame over the anterior superior iliac crest, and avoid traction on the psoas muscle during the retroperitoneal dissection.     

Evaluation of local anaesthetic blockade of the lateral femoral cutaneous nerve

An assessment of local anaesthetic blockade of the lateral femoral cutaneous nerve using a standard technique was made. The rate of successful blockade was high, but the area of sensory loss was inconsistent between patients and was more anterior and distal than described in textbooks of anatomy.     

Entrapment neuropathy of the lateral femoral cutaneous nerve: cause of lateral knee pain

This study describes the anatomy and causes of mechanical impingement of the lateral femoral cutaneous nerve, as well as the clinical findings. A female bicyclist presented with a history of lateral knee pain which was treated with stretching, arthroscopy, and change of activity. Evaluation revealed a neuropathy of the lateral femoral cutaneous nerve. The patient was treated with a heel lift and has returned to competitive cycling.J Orthop Sports Phys Ther 1988;10(3):85-86.     

The surgical anatomy of the lateral femoral cutaneous nerve in the inguinal region: a meta-analysis

Purpose

Several variations in the anatomy and injury of the lateral femoral cutaneous nerve (LFCN) have been studied since 1885. The aim of our study was to analyze the available data on the LFCN and find a true prevalence to help in the planning and execution of surgical procedures in the area of the pelvis, namely inguinal hernia repair.

Methods

A search of the major medical databases was performed for LFCN anatomy. The anatomical data were collected and analyzed.

Results

Twenty-four studies (n = 1,720) were included. The most common pattern of the LFCN exiting the pelvis was medial to the Sartorius as a single branch. When it exited in this pattern, it did so on average 1.90 cm medial to the anterior superior iliac spine (ASIS).

Conclusions

The LFCN and its variations are important to consider especially during inguinal hernia repair, abdominoplasty, and iliac bone grafting. We suggest maintaining a distance of 3 cm or more from the ASIS when operating to prevent injury to the LFCN.

     

Ultrasound-guided lateral femoral cutaneous nerve block: comparison of two techniques

The aim of this study was to compare the feasibility and efficacy between two techniques of ultrasound-guided lateral femoral cutaneous nerve with or without locating the nerve. The study enrolled 106 patients undergoing knee surgery who received 5 ml of 1% mepivacaine immediately under the inguinal ligament 1 to 2 cm medial to the anterior superior iliac spine (subinguinal technique) or around the lateral femoral cutaneous nerve located (nerve-targeting technique). The time required to perform the block and the onset time of the block were similar for both techniques. However, a significantly higher percentage of patients obtained loss of pinprick sensation on the lateral thigh within 10 minutes with the subinguinal technique than with the nerve-targeting technique. The findings suggest that ultrasound-guided lateral femoral cutaneous nerve blocks can be easily performed and that injecting local anaesthetic immediately under the inguinal ligament rather than around the nerve itself blocks the nerve more reliably.     

Anatomical variations of the lateral femoral cutaneous nerve and the consequences for surgery

PURPOSE: This two-part study was undertaken to (a) determine the course and variations of the lateral femoral cutaneous nerve in a cadaver study and (b) develop prospectively the preoperative protocol to diminish the possibility of a postoperative meralgia paresthetica; the latter was achieved by reviewing the patient series retrospectively for complaints of a lateral femoral cutaneous nerve (LFCN) lesion and by studying the relation of the course of the LFCN and meralgia paresthetica. METHODS: Anatomical studies were performed on 200 recently deceased patients. After exploring the LFCN from its origin to the inguinal region to determine its course, we classified 149 patients as "normal" and fifty-one as abnormal. We then identified eighty-two patients who, between 1989 and 1994, experienced LFCN lesion as a complication of pelvic surgery following an ilioinguinal approach. RESULTS: Thirty-seven of these patients reported altered sensation for several years postoperatively (minimum follow-up one year), including eleven patients whose complaints persisted. In five of these cases, symptoms prompted an eventual exploration of the nerve, and nerve entrapment was confirmed. Between 1994 and 1996, perioperative care intended to lessen the chance of future LFCN problems was administered to forty patients. Thirty-three patients underwent neurolysis, and seven underwent nerve transection because an LFCN lesion occurred during the operation. Within a twelve-month follow-up period, no meralgia paresthetica was noted. CONCLUSION: The practical importance of the present study lies in alerting the surgeon to a possible anatomical variation of the LFCN in about 25 percent of the patient population. It also confirms that the new perioperative protocol lowers the incidence of meralgia paresthetica.     

Femoral and lateral femoral cutaneous nerve block for muscle biopsies in children

Retrospective chart review (1978–1993) of 179 children less than age 18 (10.0 ± 3.8 SD yrs) undergoing muscle biopsy for determination of susceptibility to malignant hyperthermia provided data. One hundred and forty-six patients received femoral and lateral femoral cutaneous nerve blocks as their primary anaesthetic. We examined age, weight, duration of surgery, time to discharge from hospital, choice and dosage of local anaesthetics, choice and dosage of sedation, postoperative pain medications, and complications. All children receiving this form of anaesthesia remained outpatients. Between 1978 and 1985 procaine (10 mg·kg^-1) with hyaluronidase or 2-chloroprocaine (12 mg·kg^-1) provided nerve blockade; after 1985, lignocaine (6.8 mg·kg^-1), or a combination of lignocaine or mepivacaine and 2-chloroprocaine, were the preferred agents. More recently the combination of 2-chloroprocaine and bupivacaine has been popular. Three patients required admission to the recovery room postoperatively, due to heavy sedation. Forty-three children (29%) received pain medication during recovery. Femoral and lateral femoral cutaneous block anaesthesia with light to moderate sedation is well tolerated in children undergoing anterior thigh procedures.     

Ischemia of the lateral femoral cutaneous nerve during periacetabular osteotomy using Smith-Petersen approach

Background  

Lateral femoral cutaneous nerve (LFCN) injury is a common complication in the Smith-Petersen approach to the hip. This complication may be induced by neural ischemia or direct trauma during the procedure. The purpose of this study was to investigate the relationship between the neural ischemia of LFCN and postoperative sensory disturbance.     

Anatomic variations in the lateral femoral cutaneous nerve with respect to pediatric hip surgery

Variations were documented in the course of the lateral femoral cutaneous nerve (LFCN) in the upper thigh relative to anatomic landmarks in 22 adult cadavers using the Smith-Petersen incision for the anterior approach to the hip. Distances from the anterior superior iliac spine (ASIS) to the point of nerve entry into the thigh were normalized as percentages of the distance from the ASIS to the pubic tubercle (PT) to relate the data to small children. In all cases, the LFCN passed deep to the inguinal ligament, entering the thigh a mean of 2.6 cm (SD, 1.9 cm) medial from the ASIS (19%+/-14% of the ASIS-PT distance), with distances ranging from 0.3 to 6.5 cm (2.6%-46.4%). With the data extrapolated to children, the LFCN may commonly be found medial to the ASIS about one fifth the distance from the ASIS to the PT. In 32% of cases, the LFCN ran directly inferiorly, but in 68% it coursed inferolaterally and then turned to run inferiorly close to the distal part of the incision. Expressed proportionally rather than only as mean measurements, these percentages provide a better estimate of the location of the LFCN in relation to patient size and thus are useful when operating in this region.     

Documenting neuropathy of the lateral femoral cutaneous nerve using the Pressure-Specified Sensory Testing device

Entrapment of the lateral femoral cutaneous nerve has been difficult to document. The variability of the anatomic location of this nerve makes it difficult to measure with traditional electrodiagnostic studies. At the same time, anatomic variability increases the likelihood for this nerve to become entrapped within the inguinal ligament. The current study reports the ability to document the presence of this nerve entrapment in 24 patients, compared with 10 asymptomatic control subjects, by using nonpainful and noninvasive computer-assisted neurosensory testing with the Pressure-Specified Sensory Device.     

Injury to the lateral femoral cutaneous nerve during minimally invasive hip surgery: a cadaver study

INTRODUCTION

A smaller skin incision as part of minimally invasive surgery (MIS) for total hip arthroplasty (THA) is thought to reduce local tissue trauma. Preservation of cutaneous nerves may reduce postoperative pain and improve rehabilitation. The standard lateral approach (SLA) and two MIS approaches (anterolateral [ALA] and posterior [PA]) were compared to determine which incision preserved cutaneous nerves.

PATIENTS AND METHODS

Fifteen cadaveric hip specimens were dissected to establish the course of branches of the lateral femoral cutaneous nerve. The number of branches divided by each of the three incisions was recorded.

RESULTS

The MIS incisions resulted in significantly less nerve division compared with the SLA. The mean difference between the SLA and the ALA was 4.4 (P < 0.0001), and between the SLA and the PA was 1.4 (P = 0.0005). The ALA divided significantly fewer nerves compared with the PA (mean difference = 3; P = 0.0001).

DISCUSSION

There is little evidence of the benefit of one MIS approach over another in the literature. The ALA preserved significantly more cutaneous nerves in this study. These results need corroboration with clinical outcomes to determine their significance.     

Pseudotumoral osteochondromatosis of the hip in a soccer player

The authors present a case of pseudotumoral osteochondromatosis of the hip, interesting for its clinical and radiological features. They discuss the incidence of the sport in the pathogenesis of the loose bodies and the magnetic resonance findings.     

Compression of the palmar cutaneous nerve by ganglions of the wrist

Two cases of compression of the palmar cutaneous nerve by ganglion of the wrist are presented. The anatomy of the region, compression factors, mechanism and clinical features are discussed. Timely surgical removal of compression is recommended.