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

Variations of the extrapsoas course of the lumbar plexus with implications for the lateral transpsoas approach to the lumbar spine: a cadaveric study

BACKGROUND

Together with an increased interest in minimally invasive lateral transpsoas approach to the lumbar spine goes a demand for detailed anatomical descriptions of the lumbar plexus. Although definitions of safe zones and essential descriptions of topographical anatomy have been presented in several studies, the existing literature expects standard appearance of the neural structures. Therefore, the aim of this study was to investigate the variability of the extrapsoas portion of the lumbar plexus in regard to the lateral transpsoas approach.

METHODS

A total of 260 lumbar regions from embalmed cadavers were utilized in this study. The specimens were dissected as per protocol and all nerves from the lumbar plexus were morphologically evaluated.

RESULTS

The most common variation of the iliohypogastric and ilioinguinal nerves was fusion of these two nerves (9.6%). Nearly in the half of the cases (48.1%) the genitofemoral nerve left the psoas major muscle already divided into the femoral and genital branches. The lateral femoral cutaneous nerve was the least variable one as it resembled its normal morphology in 95.0% of cases. Regarding the variant origins of the femoral nerve, there was a low formation outside the psoas major muscle in 3.8% of cases. The obturator nerve was not variable at its emergence point but frequently branched (40.4%) before entering the obturator canal. In addition to the proper femoral and obturator nerves, accessory nerves were present in 12.3% and 9.2% of cases, respectively.

CONCLUSION

Nerves of the lumbar plexus frequently show atypical anatomy outside the psoas major muscle. The presented study provides a compendious information source of the possibly encountered neural variations during retroperitoneal access to different segments of the lumbar spine.

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.

Entrapped by pain: The diagnosis and management of endometriosis affecting somatic nerves

Somatic nerve entrapment caused by endometriosis is an underrecognized and often misdiagnosed issue that leads to many women suffering unnecessarily. While the classic symptoms of endometriosis are well-known to the gynaecologic surgeon, the dermatomal-type pain caused by endometriosis impacting neural structures is not within gynecologic day-to-day practice, which often complicates diagnosis and delays treatment. A thorough understanding of pelvic neuroanatomy and a neuropelveologic approach is required for accurate assessments of patients with endometriosis and nerve entrapment. Magnetic resonance imaging is the preferred imaging modality for this presentation of endometriosis. Surgical management with laparoscopic or robotic-assisted techniques is the preferred approach to treatment, with excellent long-term results reported after nerve detrapment and endometriosis excision. The review calls for increased awareness and education on the links between endometriosis and the nervous system, advocating for patient-centered care and further research to refine the diagnosis and treatment of this challenging condition.

Meralgia Paresthetica: A Report of a Rare Case

Meralgia paresthetica (MP) is a painful condition caused by damage or constriction of the lateral femoral cutaneous nerve (LFCN). This entrapment condition typically arises due to various factors, including trauma, pelvic tumors, external compression from belts or snug attire, and weight gain. The prognosis is generally favorable since most cases are self-limiting or respond to conservative treatment. We present the case of a 53-year-old overweight man, with no relevant medical history, who was a victim of a traffic accident in October 2023 which resulted in polytrauma, according to the Case Reports (CARE) checklist. The main complaint of the patient was tingling of the left thigh, with dysesthesia to gentle rubbing along the anterolateral surface. After a diagnostic study, a diagnosis of post-trauma MP was thus established, probably due to seat-belt compression of the LFCN, and physiatric treatment was initiated. With the assistance of ultrasound, a large hematoma was seen, above the inguinal ligament with drainage of 140ccc of serosanguineous fluid with resolution of the symptoms. This case emphasizes the importance of a physiatry consultation for a correct diagnosis and focuses on the main complaint of a polytrauma patient.

Sonographic Evaluation of the Lateral Femoral Cutaneous Nerve: Single-Institution Experience and Pictorial Review

ABSTRACT

The location of the lateral femoral cutaneous nerve (LFCN) makes it susceptible to injury with trauma, external compression, and iatrogenic injury. The objectives of this study were to report the single-institution efficacy of LFCN visualization on ultrasound (US), define the clinical characteristics of patients with LFCN palsy, and describe sonographic appearances of LFCN abnormalities by pictorial review. A retrospective chart review of LFCN cases evaluated using US at a single institution was performed, documenting rate of visibility on US, mode of nerve injury, and US imaging findings. Nerve visibility rates on US were correlated with magnetic resonance imaging (MRI) when both modalities were used. Imaging findings were confirmed with clinical/surgical history and follow-up. Retrospective review found that 170 patients underwent US for LFCN evaluation in the last 10 years. Injury was associated with surgical intervention in 56% of cases, and perineural scarring was the most common pathology described using US. Lateral femoral cutaneous nerve was visible on US in 97% of cases; MRI visualized LFCN in 60%. Chart review showed US as an effective tool in evaluating LFCN pathology, with a higher visualization rate than MRI. Through pictorial review, the array of LFCN pathology sonographically detectable is demonstrated.

Meralgia Paresthetica-An Approach Specific Neurological Complication in Patients Undergoing DAA Total Hip Replacement: Anatomical and Clinical Considerations

Introduction: Mini-invasive surgical (MIS) approaches to total hip replacement (THR) are becoming more popular and increasingly adapted into practice. THR via the direct anterior approach (MIS DAA) has become a rather controversial topic in hip arthroplasty literature in the last decades. Our retrospective observational study focuses on the prevalence of one approach-specific complication-lateral femoral cutaneous nerve (LFCN) iatrogenic lesion-and tries to clarify the possible pathogenesis of this injury. Methods: This is a retrospective single-cohort observational single-center and single-surgeon study. Our patient records were searched for the period from 2015 to 2017-after a safe period of time after the learning curve for MIS DAA. All intra- and post-operative lesions of the LFCN were recorded. Lesion of the LFCN was confirmed by a neurological examination. Minimum patient follow-up was 2 years. Results: This study involved 417 patients undergoing single-side THR via MIS DAA. Patients were examined on follow-up visits at 6 weeks, 6 months, 1 year, and 2 years after surgery. There were 17 cases of LCFN injury at the 6 weeks early follow-up visit (4.1%). All cases of clinically presenting LFCN injury resolved at the 2-year follow-up ad integrum. Discussion: Possible explanations of such neurological complications are direct iatrogenic injury, vigorous traction, hyperextension, or extreme external rotation of the operated limb. Use of a traction table or concomitant spinal pathology and deformity also play a role. Prevention involves stepwise adaptation of the approach during the learning curve period by attending cadaver lab courses, rational use of traction and hyperextension, and careful surgical technique in the superficial and deep fascial layers. Dynamometers could be used to visualise the limits of manipulation of the operated limb. Conclusions: Neurological complications are not as rare but questionably significant in patients undergoing THR via the DAA. Incidental finding of LFCN injury has no effect on the functional outcome of the artificial joint. It can lead to lower subjective satisfaction of patients with the operation, which can be avoided with careful education and management of expectations of the patients.

Ultrasonographic identification of lateral femoral cutaneous nerve anatomical variation in persistent meralgia paresthetica: A case report

BACKGROUND

Meralgia paresthetica (MP) is an entrapment mononeuropathy of the lateral femoral cutaneous nerve (LFCN). Although structural abnormalities in nerve tissues can be confirmed using ultrasonography, this is not routinely performed.

CASE SUMMARY

Herein, we present the case of a 52-year-old woman who developed MP after laparoscopic gynecological surgery. The patient was referred to our clinic from an obstetrics and gynecology clinic with symptoms of numbness and a tingling sensation in the left anterolateral thigh, which developed after surgery performed 5 mo earlier. Tests were performed to assess the disease status and determine the underlying causes. Ultrasonographic examination revealed an anatomical variation, where the left LFCN was entrapped within the inguinal ligament. This case suggests that performing ultrasonographic examination before and after surgery in the lithotomy position could help prevent MP.

CONCLUSION

This case demonstrates the value of ultrasonography in detecting anatomical variation and diagnosing persistent MP. Ultrasonography should be considered an adjunct to electromyography for optimal MP management. Further, this case would help other clinicians determine patient prognosis and decide on targeted treatment strategies.

Cadaveric Study of Variations in the Course of Lateral Femoral Cutaneous Nerve: Insight to Prevent Injury

Objective

A recent spurt in incidence of meralgia paresthetica to 0.1-81% due to minimally invasive anterior approach to hip joint has resulted in reinterest in anatomy of lateral femoral cutaneous nerve (LFCN). Familiarity with variations in the course of LFCN will reduce the morbidity associated with orthopedic procedures around the anterior superior iliac spine (ASIS) and inguinal ligament (IL).

Methods

Twenty five adult human formalin embalmed cadavers were dissected. Course and relations of nerve to ASIS, IL and sartorius muscle was noted, distance of nerve from ASIS at IL was measured and statistically analyzed.

Results

Mean distance of LFCN from ASIS at IL was 1.73±1.15 cm. Differences between two sides and sexes was statistically not significant (p=0.51 and p=0.96 respectively). Inferomedial to ASIS, 94% of LFCNs crossed IL with 92% of them present within 4 cm medial to ASIS. Majority of LFCNs (90%) exited pelvis and entered thigh posterior to IL. Out of these nerves 48% were single trunks on entry into thigh, then bifurcated into anterior and posterior branches. Remaining LFCNs bifurcated proximal to IL or at level of IL. Trifurcations were seen in 6% while a rare case of pentafication was observed. In 66% main trunk/branches were present in intermuscular cleft between sartorius muscle and tensor fascia lata.

Conclusions

Care should be exercised by surgeons while dissecting around IL as more than half of nerves are liable to be injured during operative procedures. This would help in better anticipation of problem, acceptance and reducing litigation.

Rehearsal-based digital serious boardgame versus a game-free e-learning tool for anatomical education: Quasi-randomized controlled trial

Serious games may resolve problems relating to low motivation in complex medical topics such as anatomy. However, they remain relatively novel introductions to the science of learning, and further research is required to ascertain their benefits. This study describes the overall development and testing of a digital serious boardgame designed to facilitate the rehearsal of musculoskeletal anatomy based on self-determination theory with considerations for the psychological state of Flow. It was hypothesized that students assigned to the intervention game condition would attain higher Flow scores, a measure of engagement and intrinsic motivation, than students assigned to the game-free control, and that the intervention condition would report either superior or non-superior, but not inferior, scores on a surprise recall test. A total of 36 second-year undergraduate medical students participated in the quasi-randomized controlled trial, where the intervention groups went first and randomly drew questions that were mirrored into the control groups. All students were administered an identical 10-question baseline assessment before their interventions, the Short Flow Scale immediately after, and a surprise test four-to-six weeks later. Independent samples t-tests indicated that students of both conditions were of similar baseline knowledge (t = 0.7, p = 0.47), significantly higher Flow scores in the game condition (t = 2.99, p = 0.01), and no significant differences between surprise test scores (t = -0.3, p = 0.75). The game appears to be an appropriate game-based tool for student rehearsal of anatomical education, stemming from a strong theoretical base that facilitates high engagement and intrinsic motivation.

Chiropractic management of bilateral meralgia paresthetica: a case report

Objective

The purpose of this report is to describe the course of chiropractic care for an adult male experiencing persistent anterolateral thigh pain due to bilateral meralgia paresthetica.

Clinical features

A 40-year-old male U.S. Veteran was referred to chiropractic care for a two-year history of bilateral anterolateral thigh pain and paresthesia that worsened with inguinal pressure and hip extension activities.

Intervention and outcomes

A total of six chiropractic visits, including a combination of telehealth and in-person appointments, took place over a period of 10 weeks. Treatments included patient education, soft-tissue therapy, therapeutic exercise prescription, and spinal manipulation directed toward the lumbar spine. The patient's pain was reduced from a 6/10 rating to a 0/10, he was able to reengage in recreational activities without discomfort, and sustained improvement was reported.

Summary

In this case, a trial of chiropractic care was associated with a resolution of the patient's bilateral meralgia paresthetica symptoms.

Reevaluation of the surgical indications for anterior inferior iliac spine avulsion fractures in an acute setting - A narrative review of the current literature

Purpose

The anterior inferior iliac spine (AIIS) is a frequent site of avulsion fracture in the pelvis, and these lesions could be observed mainly in teenage athletes. The present study aimed to re-evaluate the appropriate acute surgical treatment of AIIS avulsion fractures considering the three-dimensional anatomy of the supracetabular region.

Methods

This study evaluated current evidence of AIIS avulsion fracture treatments and outcomes. A literature search was done in the following databases: PubMed, SCOPUS, Embase, and Cochrane Library. All relevant information was used in this review.

Results

Several studies have shown how conservative treatment of these injuries lead to excellent outcomes, even when there is radiological evidence of displacement. However, only some surgeons describe clinical and radiological follow-up beyond six months. On the other side, recent studies have demonstrated the efficacy of arthroscopic or open procedures to solve a frequent cause of extra-articular femur-acetabular impingement (FAI) syndrome associated with previous AIIS avulsion fractures, the so-called sub-spine impingement. The acute surgical indication in AIIS avulsion fractures should be considered according to the three-dimensional anatomy of the supracetabular region, especially in young patients with high functional demands.

Conclusions

Three-dimensional assessment allows accurate evaluation of the position and dislocation of the fragment, predicting the risk of complications related to conservative treatment and guiding toward surgical indication only when appropriate.

Treatment of idiopathic meralgia paresthetica – is there reliable evidence yet?

OBJECTIVE

Meralgia paresthetica is a common condition that is usually diagnosed by its classical clinical presentation and by exclusion of a spinal origin of pain, sensory loss, and/or paresthesias in the anterolateral thigh. Treatment modalities include conservative management, local injections, and surgical therapy. To date, no level 1 evidence exists about treatment options for idiopathic meralgia paresthetica. This review article aims to give a structured overview of epidemiology, history, anatomy, diagnostics, and treatment. It focuses on the existing literature and current developments in clinical management.

METHODS

A literature search on PubMed/MEDLINE was performed on 20 December 2021, yielding 1412 results. Abstracts were screened and classified in terms of epidemiology, anatomy, diagnostics, and treatment.

RESULTS

High-quality observational data that was included in recent meta-analyses showed satisfactory results for conservative management, injections, and surgical decompression or neurectomy, but there is some major methodological criticism. For idiopathic meralgia paresthetica, the results of surgical decompression have never been compared to those of neurectomy in a randomized setup. The only study protocol published so far does not consider any extended decompression techniques (dynamic, circumferent, proximal, and distal to the inguinal ligament). A multicenter, prospective design has never been proposed.

DISCUSSION

Reliable high-quality evidence on the treatment of idiopathic meralgia paresthetica is lacking at the current state, and challenges in clinical decision-making remain.

Efficacy of neural prolotherapy in treatment of meralgia paresthetica: a case series

Background

Meralgia paresthetica is an entrapment neuropathy. Neuropathic pain was reported to be improved by using neural prolotherapy. Aim of the research was to assess and evaluate the short-term efficacy of neural prolotherapy on relieving pain, paresthesia and improving function and quality of life of patients with meralgia paresthetica. The study included 19 lower limbs with idiopathic meralgia paresthetica obtained from 15 patients. Subcutaneous perineural injection of dextrose (5%) in sterile water was given once. All patients were evaluated for outcome measures twice, at baseline visit and at follow-up visit four weeks after the injection which included: patient assessment of overall symptoms of meralgia paresthetica, patient assessment of meralgia paresthetica pain, patient assessment of meralgia paresthetica paresthesia and patient assessment of meralgia paresthetica effect on function and quality of life using visual analogue scale.

Results

There was a statistically significant improvement in the visual analogue scale of patient assessment of overall meralgia paresthetica symptoms, patient assessment of meralgia paresthetica pain, patient assessment of meralgia paresthetica paresthesia and patient assessment of meralgia paresthetica effect on function and quality of life when the findings at the postinjection visit were compared to the preinjection assessment among all patients. All the patients tolerated the injection procedure-induced pain. All the patients experienced immediate postinjection relieve of the meralgia paresthetica pain. At the postinjection assessment visit, all patients were satisfied with the procedure. There were 12 lower limbs (63.2%) from 10 patients (66.6%) that showed improvement and recovery. Two patients of them had bilateral meralgia paresthetica. There was no patient withdrawal, and no patients were lost to follow-up. There was one lower limb (5.3%) from one patient (6.7%) who had bruises at the injection sites that resolved within few days after the procedure.

Conclusions

Neural prolotherapy is easy, safe, tolerable, effective and successful in treatment of meralgia paresthetica. It is effective in relieving pain, paresthesia and improving function and quality of life of patients with meralgia paresthetica. Neural prolotherapy injection should be included in the conservative treatment armamentarium of meralgia paresthetica.

Trial registration : NCT04499911. Registered 5 August 2020—retrospectively registered.

Meralgia Paresthetica

PURPOSE OF REVIEW

This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN).

RECENT FINDINGS

There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

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

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

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.

Anterior approach to hip replacement and associated complications: an independent review

BACKGROUND

Direct anterior approach (DAA) to hip replacement is increasingly popular. Despite the well-published benefits of early recovery, the approach can be associated with a number of complications that may be underreported. We aim to report the incidence of some of these complications in a large retrospective case series.

METHODS

270 consecutive DAA hip replacements are studied which are performed by a single high-volume hip surgeon from 2013 to 2015, not including the surgeon's learning curve. Operation and consultation records were screened, and focused questioning via telephone was employed to capture specific complications including dislocations, wound infections, lateral femoral cutaneous nerve (LFCN) injury and revision surgery.

RESULTS

240 of 270 patients or family were contactable. The mean age and body mass index of the cohort was 66 (range 30-89) years and 27 (range 18-40) kg/m2 respectively. The mean follow-up was 3.7 years. Wound issues were encountered in 24 patients (8.8%). There were 9 dislocations (3%). 27 (10%) patients needed revision surgery in the follow-up period. Reasons for revision included leg-length discrepancies, dislocations, ongoing pain and aseptic loosening. 9 (3.4%) patients had to return to operating theatre for reasons other than revision surgery. Symptoms of lateral femoral cutaneous nerve injury was reported by 54 patients (21%).

CONCLUSIONS

While the short-term benefits of DAA have been widely reported, our review shows a relatively high rate of revision surgery. We feel that the enthusiasm for DAA should be tempered until further evidence is available.

Neurological Complications Following Arthroscopic and Related Sports Surgery: Prevention, Work-up, and Treatment

Arthroscopy of the shoulder, elbow, hip, and knee has become increasingly utilized due to continued advancements in technique, training, and instrumentation. In addition, arthroscopy is generally safe and effective in the utilization of joint preservation surgical techniques. The arthroscopist must utilize a thorough understanding of the surgical anatomy, detailed care with patient positioning, and safe instrumentation portals to prevent associated neurological injury. In the event of postoperative neurological complications, the physician must carefully document the patient history and physical examination while considering the utilization of additional imaging, testing, or surgical nerve exploration with a specialized team depending upon the severity of neurological injury. In this review, we discuss the prevention, evaluation, and treatment of neurological complications related for arthroscopic procedures of the shoulder, elbow, hip, and knee.

Meralgia Paresthetica: A Case Report With an Update on Anatomy, Pathology, and Therapy

Meralgia paresthetica, a condition characterized by tingling, numbness, and burning pain in the lateral aspect of the thigh, is caused by compression of the lateral femoral cutaneous nerve. The incidence of meralgia paresthetica increases with obesity and diabetes. The unique anatomy of the nerve that tunnels through the inguinal ligament predisposes it to inflammation, trauma, and entrapment. The pathology of meralgia paresthetica parallels that of entrapment neuropathies but with additional inflammatory overlay in certain instances. The clinical diagnosis is relatively simple due to its unique clinical features. The prognosis is generally excellent, and the treatment is straightforward that includes peripheral nerve blocks, neurectomy, nerve decompression, and pulsed radiofrequency neuromodulation. This current case of meralgia paresthetica highlights the salient clinical symptoms and signs. We have also described the electrophysiological studies of the lateral femoral cutaneous nerve, its anatomical variations, and the associations of meralgia paresthetica with bariatric surgery, critical care patients, tight clothing, pregnancy, and posterior spine surgery. We have also outlined the current treatment strategies.

Improvement of analgesic efficacy for total hip arthroplasty by a modified ultrasound-guided supra-inguinal fascia iliaca compartment block

Background

Fascia iliaca compartment block (FICB) is an anterior approach to the lumbar plexus block and provides the effective adjunctive analgesia for total hip arthroplasty (THA).

Methods

As a case series study, 28 patients (≥ 65 years old) with THA were received a modified in-plane ultrasound-guided supra-inguinal (S-FICB) as an analgesic adjunct to evaluate the analgesic effectiveness and the local anesthetic diffusion with magnetic resonance imaging (MRI). A combination of propofol and sufentanil was administered to conduct target-controlled infusion.

Results

The pain scores were 1 (0–4), 2 (1–5), 3 (1–6) and 3 (1–6) at 4, 8, 12, and 24 h. The cumulative opioids were 8 (8–12), 18 (16–32), 28 (24–54) and 66 (48–104) mg of i.v. morphine equivalents at 4, 8, 12, and 24 h. The patient-controlled analgesia (PCA) times were 0 (0–1), 1 (0–2), 2 (0–5) and 5 (3–8) at 4, 8, 12, and 24 h. In lateral, anterior and medial part of thigh, the sensory blockade in 28 patients was 23 (82 %), 21 (75 %) and 19 (68 %) at 5 min; 28 (100 %) at 10 and 20 min. Motor blockade of femoral nerve (FN) and obturator nerve (ON) was present in 13 (46 %) and 3 (11 %) patients at 5 min, 24 (86 %) and 9 (32 %) at 10 min, 26 (93 %) and 11 (39 %) at 20 min. Injectate permeated to the FN and extended superiorly over the surface of iliac muscle (IM) and pectineus muscle (PM) in all patients.

Conclusions

The modified S-FICB has provided an effective postoperative analgesic adjunct after THA with the satisfactory blockade of femoral (FN), obturator (ON) and sciatic (SN) nerves, especially for ON, when compared with the existing techniques.

Review: Pelvic nerves - from anatomy and physiology to clinical applications

A prerequisite for nerve-sparing pelvic surgery is a thorough understanding of the topographic anatomy of the fine and intricate pelvic nerve networks, and their connections to the central nervous system. Insights into the functions of pelvic nerves will help to interpret disease symptoms correctly and improve treatment. In this article, we review the anatomy and physiology of autonomic pelvic nerves, including their topography and putative functions. The aim is to achieve a better understanding of the mechanisms of pelvic pain and functional disorders, as well as improve their diagnosis and treatment. The information will also serve as a basis for counseling patients with chronic illnesses. A profound understanding of pelvic neuroanatomy will permit complex surgery in the pelvis without relevant nerve injury.

Effect of Fascia Penetration in Lateral Femoral Cutaneous Nerve Conduction

Objective

To evaluate the effect of fascia penetration and develop a new technique for lateral femoral cutaneous nerve (LFCN) conduction studies based on the fascia penetration point (PP) identified using ultrasound.

Methods

The fascia PP of the LFCN was localized in 20 healthy subjects, and sensory nerve action potentials (SNAPs) were obtained at four different stimulation points—2 cm proximal to the PP (2PPP), PP, 2 cm distal to the PP (2DPP), and 4 cm distal to the PP (4DPP). We compared the stimulation technique based on the fascia penetration point (STBFP) with the conventional technique.

Results

The SNAP amplitude of the LFCN was significantly higher when stimulation was performed at the PP and 2DPP than at other stimulation points. Using the STBFP, SNAP responses were elicited in 38 of 40 legs, whereas they were elicited in 32 of 40 legs using the conventional technique (p=0.041). STBFP had a comparable SNAP amplitude and slightly delayed negative peak latency compared to the conventional technique. In terms of the time required, the time spent on STBFP showed a more consistent distribution than the time spent on the conventional technique (two-sample Kolmogorov–Smirnov test, p<0.05).

Conclusion

SNAP of the LFCN significantly changed near the fascia PP, and stimulation at PP and at 2DPP provided high amplitudes. STBFP can help increase the response rate and ensure stable and consistent procedure time of the LFCN conduction study.

A study to improve identification of the retroperitoneal course of iliohypogastric, ilioinguinal, femorocutaneous and genitofemoral nerves during laparoscopic triple neurectomy

BACKGROUND

Laparoscopic triple neurectomy is an available treatment option for chronic groin pain, but a poor working knowledge of the retroperitoneal neuroanatomy makes it an unsafe technique.

OBJECT

Describe the retroperitoneal course of iliohypogastric, ilioinguinal, lateral femoral cutaneous and genitofemoral nerves, to guide the surgeon who operates in this region.

METHODS

Fifty adult cadavers were dissected resulting in 100 anatomic specimens. Additionally, 30 patients were operated for refractory chronic inguinal pain, using laparoscopic triple neurectomy. All operations and dissections were photographed. Measurements were made between the nerves of the lumbar plexus and various landmarks: interneural distances in a vertical midline plane, posterior or anterior iliac spine and branch presentation model.

RESULTS

The ilioinguinal and iliohypogastric nerves were independent in 78% (Type II) and separated by an average of 2.5 ± 0.8 cm. In surgery study, only 38% were recognized as Type II and at a significantly greater distance (3.5 ± 1.2 cm, p < 0.001). The distance between ilioinguinal and lateral femoral cutaneous nerves was also greater during surgery, with statistical significance (5.1 ± 1.5 versus 4.2 ± 1.5, p < 0.005). The distance of the nerves to their bone references were not statistically different. The genitofemoral nerve emerged from the psoas major muscle in 20% as two separate branches (Type II), regardless of the study. The lateral femoral cutaneous nerve had a mean distance of 0.98 ± 1.6 cm medial to the anterior superior iliac spine.

CONCLUSION

The identification of the IH, II, FC and GF nerves is essential to reduce the rate of failures in the treatment of CGP. The frequent anatomical variations of the lumbar plexus nerves make knowledge of their courses in the retroperitoneal space essential to ensure safe surgery. The location of the nerves in the LTN is distorted by up to 1 cm. regarding references in the cadavers.

Fine architecture of the fascial planes around the lateral femoral cutaneous nerve at its pelvic exit: an epoxy sheet plastination and confocal microscopy study

OBJECTIVE

Meralgia paresthetica is commonly caused by mechanical entrapment of the lateral femoral cutaneous nerve (LFCN). The entrapment often occurs at the site where the nerve exits the pelvis. Its optimal surgical management remains to be established, partly because the fine architecture of the fascial planes around the LFCN has not been elucidated. The aim of this study was to define the fascial configuration around the LFCN at its pelvic exit.

METHODS

Thirty-six cadavers (18 female, 18 male; age range 38-97 years) were used for dissection (57 sides of 30 cadavers) and sheet plastination and confocal microscopy (2 transverse and 4 sagittal sets of slices from 6 cadavers). Thirty-four healthy volunteers (19 female, 15 male; age range 20-62 years) were examined with ultrasonography.

RESULTS

The LFCN exited the pelvis via a tendinous canal within the internal oblique-iliac fascia septum and then ran in an adipose compartment between the sartorius and iliolata ligaments inferior to the anterior superior iliac spine (ASIS). The iliolata ligaments newly defined and termed in this study were 2-3 curtain strip-like structures which attached to the ASIS superiorly, were interwoven with the fascia lata inferomedially, and continued laterally as skin ligaments anchoring to the skin. Between the sartorius and tensor fasciae latae, the LFCN ran in a longitudinal ligamental canal bordered by the iliolata ligaments.

CONCLUSIONS

This study demonstrated that 1) the pelvic exit of the LFCN is within the internal oblique aponeurosis and 2) the iliolata ligaments form the part of the fascia lata over the LFCN and upper sartorius. These results indicate that the internal oblique-iliac fascia septum and iliolata ligaments may make the LFCN susceptible to mechanical entrapment near the ASIS. To surgically decompress the LFCN, it may be necessary to incise the oblique aponeurosis and iliac fascia medial to the LFCN tendinous canal and to free the iliolata ligaments from the ASIS.

Dynamic decompression of the lateral femoral cutaneous nerve to treat meralgia paresthetica: technique and results

OBJECTIVE

The results of lateral femoral cutaneous nerve (LFCN) decompression to treat idiopathic meralgia paresthetica (iMP) vary widely. Techniques to decompress the LFCN differ, which may affect outcome, but in MP it is unknown to what extent. The authors present a new technique using dynamic decompression and discuss the outcomes.

METHODS

A retrospective cohort study was performed in a consecutive series of 19 cases. The goal of decompression was pain relief and recovery of sensation. The plane ventral to the LFCN was decompressed by cutting the fascia lata and the inferior aspect of the inguinal ligament. The plane dorsal to the LFCN was decompressed by cutting the fascia of the sartorius muscle. Subsequently, the thigh was brought in full range of flexion and extension/abduction. The authors identified and additionally cut fibers that tightened and caused compression at various locations of the LFCN during movement in all patients, referring to this technique as dynamic decompression. Postoperatively, an independent neurologist scored pain and sensation on a 4-point scale: completely resolved, improved, not changed, or worsened. Patients scored their remaining pain or sensory deficit as a percentage of the preoperative level. Statistical assessment was done using ANOVA to assess the association between outcome and duration of preoperative symptoms, BMI, and length of follow-up.

RESULTS

In 17 of the 19 cases (89%), the pain and/or paresthesia completely resolved. Patients in the remaining 2 cases (11%) experienced 70% and 80% reduction in pain. Sensation completely recovered in 13 of the 19 cases (69%). In 5 of the 19 cases (26%) sensation improved, but an area of hypesthesia remained. Four of these 5 patients indicated a sensory improvement of more than 75%, and the remaining patient had 50% improvement. Sensation remained unchanged in 1 case (5%) with persisting hypesthesia and mild hyperesthesia. There was no significant impact of preoperative symptom duration, BMI, and length of follow-up on postoperative outcome.

CONCLUSIONS

Dynamic decompression of the LFCN is an effective technique for the treatment of iMP. Most patients become completely pain free and sensation recovers considerably.

Lateral femoral cutaneous nerve block with different volumes of Ropivacaine: a randomized trial in healthy volunteers

Background

Nerve block of the lateral femoral cutaneous nerve (LFCN) is a predominantly sensory block. It reduces pain following total hip arthroplasty (THA), but the non-responder rate is high. We hypothesized, that an increased volume of ropivacaine, would result in greater coverage of incisions used for THA.

Methods

We conducted a randomized, blinded trial in 20 healthy volunteers. Participants were randomized to receive bilateral LFCN-blocks with 8 mL ropivacaine 0.75% on the left side and 16 mL ropivacaine 0.75% on the right side, or vice versa. Allocation was blinded to both participants and outcome assessors. Before nerve block performance, incision lines for posterior and lateral THA approaches were depicted with invisible ultraviolet-paint, thereby securing sufficient blinding during outcome assessment. The blocked area was mapped using temperature and mechanical discrimination tests. Quadriceps muscle strength was monitored. Primary outcome was coverage of the posterior incision line assessed by temperature discrimination test.

Results

We found no difference in coverage of the posterior or lateral incision lines when comparing LFCN-blocks with 8 mL versus 16 mL of ropivacaine. The blocked area was significantly larger in the 16 mL group, assessed by both temperature discrimination test (p = 0.012) and mechanical discrimination test (p = 0.034). We observed no difference between groups regarding quadriceps muscle strength (p = 1.0).

Conclusions

A LFCN-block with increased volume of ropivacaine from 8 mL to 16 mL did not result in a greater coverage of posterior or lateral incision lines used for THA, but in a larger blocked sensory area.

Trial registration

Clinicaltrials.gov: NCT03138668. Registered 3rd of May 2017.

Total Hip Arthroplasty Through the Direct Anterior Approach Using a Bikini Incision Can Be Safely Performed in Obese Patients

BACKGROUND

Direct anterior approach (DAA) total hip arthroplasty can be performed through a traditional vertical incision or a horizontal (bikini) incision. The purpose of this study is to compare the 2 approaches, performed by a single surgeon past the learning curve, in terms of (1) overall wound complications and (2) patient-reported esthetics at the 6-month follow-up.

METHODS

A case-control retrospective study was conducted. Eighty-six bikini DAA patients were matched 3:1 to 230 conventional DAA patients for gender, age, body mass index (BMI), and American Society of Anesthesiologists score. Outcomes evaluated included wound complications, acute periprosthetic joint infection, transfusion, length of surgery, and dysesthesia. A subgroup analysis was also performed on obese patients, BMI greater than 30 kg/m². Furthermore, the patients rated cosmesis of the incision at 6 months using a Patient Scar Assessment Scale and the Vancouver Scar Assessment Scale.

RESULTS

Bikini patients had lower rates of delayed wound healing compared to conventional incision (2.3% vs 6.1%, P = .087). This difference was statistically significant (0% vs 16.6%, P < .05) in obese patients. There was no difference in terms of incision cosmesis between the 2 incision types.

CONCLUSION

Our study demonstrates that the DAA total hip arthroplasty can be performed safely through an alternative horizontal bikini incision with complication rates equivalent to conventional incision DAA and to those in other approaches when performed by surgeons in a high volume, efficient hip replacement institution. In patients whose BMI is >30, a potential benefit of the horizontal incision may be lower wound complications. This study design should be performed at other institutions and ideally at a multi-institution level to evaluate if results can be corroborated. Our opinion is that the horizontal bikini incision should be utilized but only after mastery of the DAA approach using the conventional vertical incision.

Prospective evaluation of lateral femoral cutaneous nerve injuries during periacetabular osteotomy

Periacetabular osteotomies (PAOs) are used to treat acetabular dysplasia in younger patients, but are not without morbidity. Lateral femoral cutaneous nerve (LFCN) injuries are commonly associated with the approach for PAOs, but the true incidence and rate of resolution is not known. The purpose of this prospective study was to determine the incidence of LFCN injuries after PAO using an innovative nerve conduction study (NCS) and to report the patient-reported outcomes. We prospectively enrolled 23 patients (24 hips) undergoing PAOs to have pre- and post-operative NCSs at a mean of 12 weeks post-operative. Patients were followed prospectively. Patients were contacted 3 years post-operatively via phone to determine the presence and severity of symptoms. Patient-reported outcome scores were also correlated with patient symptoms. Patients (91%) reported one or more LFCN symptoms post-operatively. The most common symptoms were numbness (91%), tingling (36%), pain (18%) and burning (9%). Patients (67%) had evidence of LFCN injury based on NCSs. Symptoms (40%) resolved 4 months post-operatively. Two-thirds of patients had continued symptoms at 3 years. Only 1 patient required treatment. The incidence of LFCN injury after PAO is 90%, two-thirds of which can be identified objectively by NCS. Numbness is the most common symptom. LFCN symptoms (40%) resolve by 4 months, but two-thirds of patients may continue to have thigh numbness up to 3 years after surgery. Fortunately, symptoms are not clearly associated with outcome score and treatment for this complication is rare.

Arthroscopic partial capsulotomy for exposure and treatment of hip disease

Hip arthroscopy is an effective method for the diagnosis and treatment of hip joint pathologies. However, gaining access to the central and peripheral compartments is challenging. The present study aimed to assess the advantages of using an arthroscopic extra-capsular approach and partial capsulotomy for access and subsequent management of hip diseases. Patients subjected to hip arthroscopy by partial capsulotomy for exposure and treatment of hip diseases between February 2012 and February 2016 were retrospectively analyzed. A total of 32 patients, including 19 males and 13 females, aged 19-48 years (median age, 36 years), had undergone the procedure. Firstly, the distal anterior lateral and anterolateral arthroscopic approach with blunt dissection was performed. Subsequently, a T-shaped partial capsulotomy was established to achieve adequate exposure. The shaver, radiofrequency probe and tissue penetrating suture grasper were then inserted to perform procedures including debridement of the synovium, suturing of the glenoid labrum. During surgery, a probe hook was used to push the capsule section limbs or pull the sutures placed on the capsule section limbs to improve exposure. For patients with pre-operative anterior instability, ligamentous laxity or acetabular dysplasia capsules were sutured to finish capsule closure. The pre-operative and post-operative Visual Analogue Scale (VAS) score and modified Harris hip score (MHHS) were used to assess the effectiveness of the procedure. No obvious post-operative complications were encountered. The mean follow-up time was 22.4 months (range, 18-32 months) and 31 patients completed the follow-up, while 1 patient was lost to follow-up. Compared with the pre-operative score, the MHHS was significantly increased (66.2±6.0 vs. 82.6±5.2; P<0.05) and the VAS score was significantly decreased (6.5±1.1 vs. 1.2±0.7; P<0.05) at the end of the follow-up. In conclusion, arthroscopic partial capsulotomy provides access to the peripheral and central compartments of the hip and is a relatively simple technique that is easy to master for surgeons with limited experience in hip surgery.

Update on Selective Regional Analgesia for Hip Surgery Patients

In hip surgery, regional anesthesia offers benefits in pain management and recovery. There are a wide range of regional analgesic options; none have shown to be superior. Lumbar plexus block, femoral nerve block, and fascia iliaca block are the most supported by published literature. Other techniques, such as selective obturator and/or lateral femoral cutaneous nerve blocks, represent alternatives. Newer approaches, such as quadratus lumborum block and local infiltration analgesia, require rigorous studies. To realize long-term outcome benefits, postoperative regional analgesia must be tailored to the individual patient and last longer.

Sensory distribution of the lateral femoral cutaneous nerve block - a randomised, blinded trial

BACKGROUND

The lateral femoral cutaneous nerve (LFCN) block may be used for post-operative pain management in patients undergoing total hip arthroplasty. The aim of this trial was to investigate the sensory coverage of the posterior and the lateral incision lines and the involvement of the femoral nerve after an LFCN block.

METHODS

The study was a randomised, blinded trial in 20 healthy volunteers. All subjects received a bilateral LFCN block randomised to 8 ml ropivacaine on the right side and 8 ml isotonic saline on the left side, or vice versa. An orthopaedic surgeon depicted the incision lines (invisible to the investigators) prior to block performance. The distribution of the blocked area and the coverage of the incision lines were assessed with temperature discrimination and pinprick test before unblinding the incision lines. Pain during tonic heat stimulation and involvement of the femoral nerve by measuring quadriceps strength were assessed.

RESULTS

The mean difference in block coverage of the posterior (primary outcome) and the lateral incision lines tested with temperature discrimination were 5.8% (95% CI: -2.2 to 14.0%, P = 0.146) and 18.9% (95% CI: 6.5-31.4%, P = 0.005), respectively, comparing the active with the placebo side. A varying anatomic distribution area was observed. No clinically significant differences for experimental pain and quadriceps muscle strength were found. The block failure rate was 15%.

CONCLUSION

An LFCN block consisting of 8 ml 0.75% ropivacaine had limited coverage of the posterior and lateral incision lines.

Anatomic Variation in Patient with Lateral Femoral Cutaneous Nerve Entrapment Neuropathy

BACKGROUND

We report a surgical case of entrapment neuropathy of lateral femoral cutaneous nerve (LFCN) with anatomical variation.

CASE DESCRIPTION

This 53-year-old man had a 10-year history of paresthesia and pain in the right anterolateral thigh exacerbated by prolonged standing and walking. His symptoms improved completely but transiently by LFCN block. The diagnosis was LFCN entrapment. Because additional treatment with drugs and repeat LFCN block was ineffective, we performed surgical decompression under local anesthesia. A nerve stimulator located the LFCN 4.5 cm medial to the anterior superior iliac spine. It formed a sharp curve and was embedded in connective tissue. Proximal dissection showed it to run parallel to the femoral nerve at the level of the inguinal ligament. The inguinal ligament was partially released to complete dissection/release. Postoperatively, his symptoms improved and the numeric rating scale fell from 8 to 1.

CONCLUSION

We report a rare anatomical variation in the course of the LFCN.

Evaluation of the Neo-umbilicus Cutaneous Sensitivity Following Abdominoplasty

BACKGROUND

Abdominal cutaneous sensitivity loss after abdominoplasty is an undesirable outcome. However, little is known in the literature about sensitivity changes of the neo-umbilicus after abdominoplasty. The aim of this study was to evaluate post-abdominoplasty cutaneous sensitivity of the neo-umbilicus using clinical, quantitative, and reproducible methods.

METHODS

Patients who underwent abdominoplasty were included, whereas the control group consisted of healthy volunteers with similar demographic characteristics but who did not undergo abdominoplasty. The umbilicus was divided into five zones, and superficial tactile sensitivity and spatial orientation were assessed subjectively (score 1-4) and objectively (Semmes-Weinstein monofilament examination).

RESULTS

Twenty patients (45 ± 12 years) operated on consecutively between April 2012 and May 2016 and 14 healthy volunteers in the control group (39 ± 9 years) could be included. Although there were statistically significant differences (p = 0.0005) in the average cutaneous pressure thresholds between the control group (0.4 g/mm², range 0.07-2 g/mm²) and the study group (0.4 g/mm², range 0.07-4 g/mm²), patient satisfaction after a mean follow-up of 33 ± 16 months (range 10-62 months) was acceptable (mean satisfaction score 1.8 ± 0.7). Furthermore, spatial perceptions were precise in all patients and similar to the control group.

CONCLUSION

Our long-term results indicate that spontaneous reinnervation of the neo-umbilicus after abdominoplasty together with accurate spatial orientation can occur.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Technical success of the ultrasound-guided supra-inguinal fascia iliaca compartment block in older children and adolescents for hip arthroscopy

BACKGROUND

Hip arthroscopic surgery is performed on older pediatric patients. Fascia iliaca compartment block has proven efficacy in providing analgesia following hip surgery and can be performed with target location of local anesthetic below or above the inguinal ligament. The reported success of ultrasound-guided infra-inguinal fascia iliaca compartment block is lower when compared to traditional landmark technique, while the reliability of supra-inguinal fascia iliaca compartment block is unreported.

AIM

The primary aim was to report the results in obtaining sensory changes in the distribution of the femoral and lateral femoral cutaneous nerves following supra-inguinal fascia iliaca compartment block in patients undergoing arthroscopic hip surgery. Secondary outcomes are the ability to find echogenic landmarks and to report pain scores and opioid consumption.

METHODS

We reviewed the electronic medical record and regional anesthesia database of patients receiving ultrasound-guided fascia iliaca compartment block for arthroscopic hip surgery. Sensory changes to the femoral and lateral femoral cutaneous nerves were determined. Identification of echogenic landmarks was quantified. Pain scores and opioid consumption were determined.

RESULTS

Seventeen patients of mean age 15.4 years old (SD 1.3; range 13-17 years) were included. Sensory changes to both the femoral and lateral femoral cutaneous nerves occurred in 94% of patients (95% CI: 82%-100%). The average volume of ropivacaine 0.2% was 0.53 mL/Kg (SD 0.11 mL/Kg). Echogenic landmarks were identified in all patients. Pain scores and opioid consumption were generally low.

CONCLUSION

A supra-inguinal location for the deposition of local anesthetic when performing fascia iliaca nerve block for hip surgery is reliable in anesthetizing the femoral and lateral femoral cutaneous nerves and should encourage investigation into the clinical efficacy.

Endopelvic Approach for Iliac Crest Bone Harvesting

BACKGROUND

The anterior approach to lumbar spine surgery has grown in popularity in the past few years; spinal fusion of the last 2 lumbar levels is often required. Although alternatives to bone grafting are available, including recombinant human bone morphogenetic protein 2 or bone substitutes, only cancellous autologous bone has all the required factors for bone growth. To avoid the use of bone substitutes, remote iliac crest bone harvesting remains the gold standard. However, this technique may lead to some unfavorable outcomes.

CASE DESCRIPTION

The patient was a 46-year-old man with severe back and left leg pain. Magnetic resonance imaging showed an inflammatory discopathy of L5-S1 associated with a left posterior lateral herniated disc. Conservative treatment failed, and surgical treatment of the lumbar disk disease and the herniated disc was scheduled. A novel iliac crest bone harvesting method was performed during the retroperitoneal approach to the anterior lumbar interbody fusion. The patient's postoperative course was uneventful. There were no adverse outcomes related to the bone donor site.

CONCLUSIONS

This is the first in vivo report of endopelvic iliac crest bone harvesting. This technique allows bone graft harvesting to be performed with the same retroperitoneal approach used for anterior lumbar interbody fusion. It avoids many common complications associated with the remote approach to the iliac crest.