Sciatic Foramen Research Articles

Anatomical Analysis of the Superior Gluteal Artery in 100 Women for Superior Gluteal Artery Perforator Flap Breast Reconstruction.

The superior gluteal artery (SGA) perforator (SGAP) flap is used more rarely for breast reconstruction with autologous tissue than other flaps because the SGA is often narrow, and the SGAP can be short. However, it provides ample fat, including in lean women. To improve its safety and utility, the preoperative SGA course in women who underwent autologous breast reconstruction was determined with three-dimensional computed tomography angiography. Consecutive deep inferior epigastric perforator, profunda artery perforator, and SGAP flap cases in 2019-2023 were identified. Frequencies of the following favorable preoperative SGA-anatomy variables were determined: branching of the main-SGA trunk on top/posterior of the greater sciatic foramen (designated M1/2), which allows access to a sufficiently wide SGA artery; superolateral perforating location of the superficial-SGA branch (SP3), which means the perforator is sufficiently long for uncomplicated flap placement; and nonbranching of the deep-SGA branch (D1/D2), which means this branch can used a venous and an arterial graft to extend an insufficiently long perforator. A total of 100 cases of deep inferior epigastric perforator (n = 80), profunda artery perforator (n = 13), and SGAP flap-based breast reconstructions (n = 7) were identified. Out of 200 buttocks, 89%, 91.5%, and 62% had the favorable M1/2, SP3, and D1/D2 variables, respectively. An atypical descending branch feeding the lower buttocks (DES1/2) was observed in 34%. The branching position of the main-SGA trunk, perforating location of the SGAP, and the shape of the deep branch were classified in detail in 100 patients. By creating a surgical plan that understands the anatomy taking preoperative three-dimensional computed tomography angiography, the SGAP flap can accommodate many patterns, increasing the possibility of safe execution.

A rare case report of inverse sciatic hernia unveiling as a lipoma

Abstract When a swelling arising in the gluteal region herniates into the pelvic cavity through the sciatic foramen, it is referred to as inverse or reverse sciatic hernia and is a rare occurrence. We present the case of a 62-year-old female who presented with swelling in the left gluteal region with features of sciatica and abdominal pain. Magnetic resonance imaging showed 27 cm × 22 cm × 9 cm soft tissue swelling arising from the gluteal region and inversely herniating into the pelvic cavity through the sciatic foramen. We were successful in delivering the tumor through a gluteal approach. Lipomatous tumors presenting as inverse sciatic hernia are a rare event.

Necrotizing fasciitis of the thigh secondary to perforated rectal cancer: the sciatic foramen as a route for infective spread

Necrotizing fasciitis of the thigh secondary to perforated rectal cancer: the sciatic foramen as a route for infective spread

LINDBLOM HERNIA: URETER INCARCERATION IN LEFT SCIATIC FORAMEN. LAPAROSCOPIC APPROACH

Abstract Background Sciatic hernias are thought to be secondary to a partial loss of pelvic fascia, atrophy of the piriformis, congenital deformity, or a combination of either. Hernia sac may contain small bowel, ureter, ovary, colon or bladder. Patients may have diverse symptoms and signs ranging from abdominal or pelvic pain or with complications due to incarceration of their contents such as ureteric or bowel obstruction. The Curlicue sign is described as ureteric obstruction with U-shaped tortuosity through the sciatic foramen which is pathognomonic of uretero-sciatic hernia. Various surgical approaches have been reported in the literature, from open laparotomy, abdominoperineal/trans-gluteal approach, to laparoscopy and minimally invasive approach to repair it. The defect can be repaired with a mesh, non-absorbable sutures, and reinforced with a peritoneal flap or epiplon. Method We describe a laparoscopic approach of a left-sided ureterosciatic hernia (Lindblom hernia) who associate an ipsilateral inguinal and obturator defect. Results 80-year-old female come to our center with left flank pain associated with a decline in renal function. A CT scan showed severe left-sided hydro-nephrosis, and the diagnosis of Lindblom hernia was made. A JJ tube was inserted, which relieved the obstruction and improved the renal function preoperatory. A laparoscopic approach via TAPP was perform and the patient was discharged without complications in 24 hours. Conclusion Sciatic hernia are a rare cause of chronic pelvic pain and various surgical approaches have been reported to repair it.

Anatomical Proximity Between Sciatic Nerve and Ischial Spine and its Relationship to the Development of Deep Gluteal Pain Syndrome

Deep gluteal syndrome (DGS) is a medical diagnosis in which the pathoanatomy of the subgluteal space contributes to pain. The growing recognition that gluteal neuropathies can be associated with the presence of a bone-neural conflict with irritation or compression may allow us to shed some light on this pathology. This study aims to determine whether the location of the sciatic nerve (SN) in relation to the ischial spine (IS) contributes to the development of DGS. The SN - IS relationship was analyzed based on magnetic resonance imaging (MRI) in 15 surgical patients (SPs), who underwent piriformis release, and in 30 control patients who underwent MRI of the pelvis for reasons unrelated to sciatica. The SN exit from the greater sciatic foramen was classified as either zone A (medial to the IS); zone B (on the IS); or zone C (lateral to the IS). The SN was significantly closer to the IS in SPs than in MRI controls (P= 0.014). When analyzing patients of similar age, SNs in SPs were significantly closer (P= 0.0061) to the IS, and located in zone B significantly more (P= 0.0216) as compared to MRI controls. Patients who underwent surgery for piriformis release showed a significant decrease in pain postoperatively (P < 0.0001). The results from this study suggest that the relationship between the IS and SN may play a role in the development of DGS. This may also help establish which patients would benefit more from surgical intervention.

Sonographically-guided Parasacrum Infrapiriformis Drainage of Deep Pelvic Abscesses: An Anatomical Safety Study Using SYNAPSE VINCENT.

Deep pelvic abscesses are surrounded by the pelvic bones, bladder, gynecological organs, intestinal tract, and nerve and vascular systems, and are approached by various routes for drainage. The transgluteal approach is often performed under computed tomography guidance; however, if ultrasonography can be used to confirm the approach, it is considered more effective because it reduces radiation exposure and allows for real-time puncture under sonographic and fluoroscopic guidance. This retrospective study was conducted at Tobata Kyoritsu Hospital (Fukuoka, Japan) between April 1, 2021, and December 31, 2022. Sonographically guided transgluteal drainage with fluoroscopy was performed in five consecutive cases of deep pelvic abscesses using a 3D image analysis system (SYNAPSE VINCENT) to study the anatomy for safe puncture. Three patients had postoperative abscesses from colorectal cancer, one caused by perforation of the appendicitis, and one caused by sigmoid diverticulitis. The average drainage duration was 11 days (SD = 6.7). No complications, such as bleeding or nerve damage, were observed. We constructed a 3D image of the puncture route of the trans greater sciatic foramen using SYNAPSE VINCENT to objectively comprehend the anatomy and puncture route. The ideal transgluteal approach is to insert the catheter as close to the sacrum as possible at the level of the infrapiriformis. The parasacrum infrapiriformis approach can be performed safely and easily using ultrasound guidance and fluoroscopy.

Pudendal Nerve Neurolysis in Patients Afflicted With Pudendal Nerve Entrapment: A Systematic Review of Surgical Techniques and Their Efficacy.

To assess the effectiveness and safety of various techniques of pudendal nerve neurolysis (PNN) in patients with pudendal nerve entrapment (PNE). A comprehensive literature search was conducted on May 20th, 2023, using Scopus, PubMed, and Embase databases. Only studies in English involving adults were accepted, while meeting abstracts and preclinical studies were excluded. A total of 34 papers were included. Transperineal PNN emerged as a promising technique, demonstrating significant potential in alleviating pain, restoring erectile function in males, and improving the resolution of urinary stress incontinence in females. Furthermore, the bilateral approach consistently yielded positive outcomes in addressing urinary symptoms. The transgluteal technique appeared particularly suitable for cases of posterior PNE, situated between the sacrospinous ligament and the lesser sciatic foramen. A progressive amelioration of painful symptoms was observed during follow-up. Minimally invasive PNN is evolving and enables decompression along the entire proximal tract up to the Alcock canal, minimizing the risk of comorbidities. In addition to reducing pudendal neuralgia, robot-assisted and laparoscopic approaches determined a reduction in lower urinary tract symptoms and an improvement in erectile function, though further studies are required to corroborate these findings. PNN emerges as an effective treatment for PNE with minimal morbidity. Therefore, PNN should be tailored according to the site of PNE to enhance functional outcomes and improve patient quality of life.

Surgical anatomy of superior gluteal artery in relation to lumbosacral plexus – A cadaveric study in the Indian population

Background: The superior gluteal artery (SGA) passes in between branches of the lumbosacral plexus after arising from the internal iliac artery. Variations in the course of SGA from the internal iliac artery till it passes out of the pelvis through the greater sciatic foramen are very important during pelvic surgeries. Pseudoaneurysm of SGA caused by iatrogenic injuries can compress branches of the lumbosacral plexus, causing foot drops and sciatica. Aims and Objectives: The aim is to study the course of the SGA in relation to branches of the lumbosacral plexus. Materials and Methods: A cross-sectional observational study was done on 25 formalin-fixed human adult cadavers. Dissections were performed in the pelvic region and branches of the internal iliac artery and lumbosacral plexus were identified. SGA was traced on both sides from origin till passing out of the greater sciatic foramen and its relation to branches of lumbosacral plexus was recorded. Results: Three types of pathways taken by SGA were identified in relation to the lumbosacral plexus. The most common path taken by the SGA was between the lumbosacral trunk (LST) and the first sacral nerve. Thirty-five out of 50 were of this type (70%). Ten out of 50 had the second most common type which was between L4 and L5 branches of LST (20%). Five cadavers had SGA lateral to LST (10%). Ten cadavers out of 25 (40%) had side differences in the type of course taken by SGA in relation to the lumbosacral plexus. Conclusion: A surgeon must keep in mind variations in the path taken by SGA in relation to the lumbosacral plexus to prevent pseudoaneurysms of SGA, which in turn can compress branches of lumbosacral plexus, causing foot drop and sciatica.

Sub-gluteal ligation of the internal pudendal vein for management of veno-occlusive erectile dysfunction (Shaeer's Vein Ligation-I): the cadaveric study.

Vein ligation for veno-occlusive erectile dysfunction is being abandoned due to the recurrence rate. Among the reasons for failure is inability to ligate the deep system of veins; the internal pudendal vein. The vein exits the pelvis in the gluteal region, from the lesser sciatic foramen to the greater sciatic foramen, coursing over the ischial spine and sacro-spinous ligament, under the gluteus maximus. This work aims to verify feasibility of the first surgical procedure to ligate the internal pudendal vein through the gluteal approach. This cadaveric study involved five formalin-fixed cadavers. A surface anatomical landmark was designed to identify the ischial spine, at the intersection of two lines: a vertical line from posterior superior iliac spine to ischial tuberosity, and a horizontal line extending from sacro-coccygeal joint, laterally. An incision is cut encompassing the target point. Subcutaneous fat is dissected down to the gluteus maximus, which is split along the direction of its fibers. The vein can be found crossing over the ischial spine. "Shaeer's Vein Ligation - I" appears to be surgically feasible. A protocol for a surgical study is registered at clinicaltrials.gov, and is open for participation.

Anatomical Relationships of the Sciatic Nerve and Pudendal Nerve to the Ischial Spine as They Exit the Greater Sciatic Foramen

Deep gluteal syndrome is a clinical condition in which discomfort may arise due to the pathoanatomy of the subgluteal space. In this study, we conducted an anatomical exploration to categorize the relationship of the piriformis muscle, sciatic nerve, and pudendal nerve to the ischial spine and sacrospinous ligament.Twenty-two cadavers were analyzed. The piriformis muscle, sciatic nerve, and pudendal nerve were exposed either through a transgluteal approach or a gluteal flap. The relationship of the neural structures to the ischial spine, sacrospinous ligament, and ischial bone as they exit the greater sciatic foramen was observed and the exit zones were classified as either: zone A medial to the ischial spine (entirely on sacrospinous ligament), zone B on the ischial spine, and zone C lateral to the ischial spine (entirely on ischial bone).The sciatic nerve was observed either in zone B or zone C in all specimens. The pudendal nerve was found to be either in zone A or B in 97.6% of specimens. The most common combinations were sciatic nerve in zone B and pudendal nerve in zone A (Type I), and sciatic nerve in zone C and pudendal nerve in zone B (Type II).The results from this study show clear anatomical differences in the sciatic nerve-pudendal nerve relationship, which may play a role in pain seen in deep gluteal syndrome. Moreover, classification of the sciatic nerve-ischial spine and pudendal nerve-ischial spine relationships described in this manuscript will help describe different pathologies affecting the deep gluteal area.

Ureterosciatic Hernia in Focus: A Narrative Review of the Literature.

Pelvic herniation of the ureter through anatomical musculoskeletal foramina stands out as one of the rarest causes of ureteric obstruction. Historically, most cases have been documented as incidental intraoperative findings. The herniation of the ureter through the sciatic foramen presents as a particularly uncommon variant of this condition, distinguished by its potential to cause life-threatening sepsis or renal failure if not promptly recognized and treated. The diagnostic process remains challenging, attributed partly to the vague initial symptomatology and subtle radiological findings, and second, to the rarity of this condition. This challenge may be further compounded by the lack of a clear description of clinical features and pathways to raise clinician suspicion. In light of these considerations, we conducted this literature review to illuminate this unique cause of obstructive uropathy, aiming to delineate its clinical features and explore common diagnostic and treatment options.

Ultrasound Imaging of the Sciatic Nerve.

The sciatic nerve (SN) is the biggest nerve in the human body and innervates a large skin surface of the lower limb and several muscles of the thigh, leg, and foot. It originates from the ventral rami of spinal nerves L4 through S3 and contains fibers from both the posterior and anterior divisions of the lumbosacral plexus. After leaving the neural foramina, the nerve roots merge with each other forming a single peripheral nerve that travels within the pelvis and thigh. Non-discogenic pathologies of the SN are largely underdiagnosed entities due to nonspecific clinical tests and poorly described imaging findings. Likewise, to the best of our knowledge, a step-by-step ultrasound protocol to assess the SN is lacking in the pertinent literature. In this sense, the aim of the present manuscript is to describe the normal sono-anatomy of the SN from the greater sciatic foramen to the proximal thigh proposing a standardized and simple sonographic protocol. Then, based on the clinical experience of the authors, a few tips and tricks have been reported to avoid misinterpretation of confounding sonographic findings. Last but not least, we report some common pathological conditions encountered in daily practice with the main purpose of making physicians more confident regarding the sonographic "navigation" of a complex anatomical site and optimizing the diagnosis and management of non-discogenic neuropathies of the SN.

Malignant peripheral nerve sheath tumor in the pelvis: a case report

BackgroundMalignant peripheral nerve sheath tumors (MPNSTs) are malignancies that arise or differentiate from or infiltrate peripheral nerves and account for approximately 5% of soft-tissue malignancies. Approximately half of MPNSTs develop in patients with neurofibromatosis type 1 (NF1), a hereditary disease. MPNSTs occur mainly in the trunk, proximal extremities, and neck, but can on rare occasion arise in or near the gastrointestinal tract, and intestinal complications have been reported. We describe herein a case with resection of an MPNST arising in the pelvic region.Case presentationA 51-year-old woman had undergone repeated resections for systemic neurofibrosis associated with NF1. This time, a pelvic tumor was noted on follow-up positron emission tomography computed tomography (CT). She presented with slowly progressive radiating pain in the lower extremities and was referred to our hospital for tumor resection. Contrast-enhanced CT showed a 75 × 58-mm mass in the right greater sciatic foramen directly below a 24 × 28-mm mass. Open pelvic tumor resection was performed for pelvic neurofibroma. The obturator nerve was identified lateral to the main tumor and the sciatic nerve was identified dorsally, then dissection was performed. The closed nerve was spared, while the sciatic nerve was partially dissected and the two tumors were removed. Both tumors were elastic and hard. Pathologic findings were MPNST for the large specimen and neurofibroma with atypia for the small specimen. The patient developed temporary postoperative ileus, but is generally doing well and is currently free of recurrence or radiating pain. The patient is at high risk of recurrence and close monitoring should be continued.ConclusionsWe encountered a rare case of MPNST. Due to the high risk of recurrence, surgery with adequate margins was performed, with a requirement for appropriate follow-up.

Superior Gluteal Nerve Anatomy and Its Injuries: Aiming for a More Secure Surgical Approach of the Pelvic Region.

Because most of the recognized causes of superior gluteal nerve (SGN) injury are iatrogenic, detailed knowledge of the anatomy of the SGN is crucial to prevent its injury associated with surgical procedures. This study aims to describe the precise location of SGN or its branches at the greater sciatic foramen, measure the distances of these neural structures to palpable bony landmarks, and evaluate the possible correlation between these parameters and pelvis size. Twenty human cadaveric hemipelvises were studied. After dissection to expose the SGN or its branches at the greater sciatic foramen, the distances from these neural structures to the greater trochanter (GT), to the anterior superior iliac spine (ASIS), to the posterior superior iliac spine (PSIS), to the ischial tuberosity (IT), and to the greater sciatic notch apex were measured. We found that at the greater sciatic foramen, the SGN emerges as a common trunk in 75% of hemipelvises, and already divided in its superior and inferior branches in 25% of hemipelvises. When the SGN exits the pelvis as a common trunk, it does so, in most cases, in contact with the bone at the apex of the greater sciatic notch or superior to the level of the apex. The median distance from the SGN at the greater sciatic notch to the PSIS, ASIS, GT and IT is 7.6 cm, 10.9 cm, 7.5 cm and 10.8 cm, respectively. We found a positive correlation between some of the analyzed parameters and the size of the pelvis. The anatomical data of this study may serve as pivotal guides during orthopedic pelvic surgery, contributing to minimize SNG iatrogenic lesions with significant implications in the patient's quality of life.

Gluteal Muscle Size and Quality in Professional Ballet Dancers Compared to Non-Dancing Athletes.

Professional ballet dancers load their hips in extreme ranges of motion and commonly report hip pain. Evaluating gluteal muscle size and quality may help guide exercise programs. Objectives of this study were to compare gluteal muscle size and quality (fatty infiltration) in ballet dancers compared to athletes; and to investigate the relationship between gluteal muscle size and quality, and reports of hip-related pain. This study was a case-control design. Professional ballet dancers (current and retired, n = 49, mean age 35 years, range 19-63) and age and sex-matched athletes (current and retired, n = 49) underwent magnetic resonance imaging of both hips. Muscle cross-sectional areas (CSA) were obtained at standardized landmarks for gluteus maximus (GMax) and gluteus medius (GMed). Full muscle volume was calculated for gluteus minimus (GMin). Fatty infiltration was rated using the Goutallier classification system. Muscle size was compared between groups using linear mixed models. Fatty infiltration was compared using a mixed model binary logistic regression. Hip-related pain, participation status, limb side and sex were included as covariates. Ballet dancers had significantly larger GMax (upper P < .01, middle P < .01, lower P = .01) and GMed (level of anterior inferior iliac spine P < .01, greater sciatic foramen P < .01) CSA and larger GMin volume (P < .01), when normalized to weight. There was no difference in fatty infiltration ratings between dancers and non-dancing athletes. Retired dancers and athletes reporting hip-related pain were more likely to have fatty infiltration in GMax lower (P = .04). Gluteal muscles are larger in ballet dancers compared to athletes suggesting high-level loading of these muscles. There is no relationship between hip-related pain and gluteal muscle size. Dancers and athletes have comparable muscle quality.

THE BILATERAL HIGH DIVISION OF THE SCIATIC NERVE IN THE PELVIS

The sciatic nerve is the thickest nerve of the body.1 It leaves the pelvis below the piriformis via the greater sciatic foramen and descends between the ischial tuberosity and greater trochanter in the back of the thigh, dividing into the tibial and common peroneal nerves proximal to the knee however, the level of bifurcation can be variable.2The levels of division of the sciatic nerve are important in anaesthesia, orthopaedics, rehabilitation, and neurology.3The study was done by dissection of forty-two human adult lower limb specimens, irrespective of sex from the Department of Anatomy, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India. During dissection, 02(4.8%) specimens out of 42 specimens showed high division, 28(66.6%) specimens showed intermediate, and 12 (28.6%) specimens showed low division of the sciatic nerve.The bilateral highdivision of the sciatic nerve is a rare variation. Knowledge about the level of division of the sciatic nerve is important for clinicians and surgeons.

Nerve relationships to the sacrospinous ligament: application to suspension procedures and transgluteal approaches for nerve repair and tumor removal with three case illustrations.

Transvaginal suspension procedures often use the sacrospinous ligament (SSL), which attaches onto the ischial spine (IS). However, nerve-related sequelae (e.g., sciatic nerve injury) following such procedures have been reported. Therefore, the current anatomical study was performed to better understand these relationships. Additionally, three case illustrations of patients with injury to the sciatic nerve following sacrospinous ligament suspension procedures are included to exemplify the significance of a thorough knowledge of this anatomy. In 20 human adult cadavers (40 sides), a gluteal dissection was performed to expose the IS and SSL and regional nerves near the greater sciatic foramen. Measurements between the IS and SSL were made between these structures and surrounding nerves. The average distance between the IS and sciatic nerve was 1.4cm. From this bony part, the average distance to the S1 and S2 ventral rami was 3.1cm and 1.9cm, respectively. From the IS to the lumbosacral trunk, pudendal nerve, nerve to obturator internus, and superior gluteal nerve, the mean distance was 4cm, 0.5cm, 0.7cm, and 4.5cm, respectively. From the SSL to the lumbosacral trunk, S1 ventral ramus, and S2 ventral ramus, there was an average distance of 4.2cm, 1.6cm, and 0.8cm, respectively. Statistically, in females, the distances from the IS and SSL to the sciatic nerve, lumbosacral trunk, superior gluteal nerve, and S1 and S2 ventral rami were shorter when compared to males. An improved understanding of the relationship between the SSL and IS and nerves near the greater sciatic foramen can lead to fewer intraoperative complications during approaches to various peripheral nerves in this region. Lastly, these relationships might help better understand the nerve injuries following pelvic suspension procedures that use the SSL.

The AIUM Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination.

The AIUM Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination.

Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21

ObjectiveTo establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS). MethodsWe retrospectively reviewed tibial nerve SEP findings in patients having MRI-confirmed LSS at the cauda equina or conus/epiconus region. P15 and N21 potentials were recorded and the following findings were defined as localizing abnormalities: 1) normal P15 latency either with prolonged P15-N21 interval or with absent N21; 2) decreased ratio of the N21 amplitude to P15 amplitude. As non-localizing abnormalities, N21 and P38 latencies were also evaluated. Tibial nerve F-wave findings were also investigated. ResultsAccording to the entry criteria, 18 patients were included, 15 with cauda equina lesions and 3 with conus/epiconus lesions. Localizing abnormalities in SEPs were found in 67% of patients, achieving significantly higher sensitivity than delayed P38 latency (28%), and higher sensitivity than N21 abnormalities (39%), though this was not significant. Localizing abnormalities were observed even in 6 out of 11 patients lacking both sensory symptoms and signs. Tibial nerve F-wave was abnormal in 36% of 14 patients with F-wave examinations, whereas the localizing abnormalities in SEPs were found in 64% of the same patient population. P15 amplitude was depressed in 4 patients (22%), which may indicate the involvement of the dorsal root ganglion in LSS, although its latency was normal even for these patients. ConclusionsTibial nerve SEPs with the recording of P15 and N21 potentials achieved sufficiently high sensitivity in diagnosing LSS. They have the advantage over F-wave in that they can localize the lesion at the cauda equina or conus/epiconus level. SignificanceTibial nerve SEPs are promising in evaluating LSS, especially in documenting sensory tract involvement in cases lacking sensory symptoms/signs.

VARIATIONS OF SCIATIC NERVE BIFURCATION: A CADAVERIC STUDY

Background: The sciatic nerve is formed in the pelvic cavity and leaves the cavity through the greater sciatic foramen below the piriformis muscle. It terminates by giving tibial and common peroneal (fibular) nerve near the superior angle of the popliteal fossa. Awareness of variations in bifurcation of sciatic nerve is significant during deep intramuscular gluteal injections, clinical conditions such as piriformis syndrome, sciatica, coccygodynia and muscle atrophy. The main objective of this study was to highlight the site of bifurcation of sciatic nerve. Methods: An observational cross–sectional study was performed in the Department of Anatomy of KIST medical college &amp; Teaching Hospital, Lalitpur, Nepal. The data was collected after ethical approval from Institutional Review Committee. 50 specimens were taken in the study by convenient sampling method. Sciatic nerve was observed in respect to its site of bifurcation. Results: Out of 50 lower limbs, in 30 specimens (60%) the sciatic nerve showed bifurcation near the superior angle of popliteal fossa. 20 lower limbs (40%) showed variations,of which eight limbs (16%) showed division of nerve prior to its exit in the gluteal region, eight limb (16%) showed division in upper 2/3rd of back of thigh and four limbs (8%) showed division of the nerve in the popliteal fossa. Conclusions: This study concludes that the majority of sciatic nerve divides at the superior angle of the popliteal fossa while some divided into other regions such as pelvis, thigh &amp; popliteal fossa.