Piriformis Research Articles

The Cross-Sectional Area Assessment of Pelvic Muscles Using the MRI Manual Segmentation among Patients with Low Back Pain and Healthy Subjects.

The pain pathomechanism of chronic low back pain (LBP) is complex and the available diagnostic methods are insufficient. Patients present morphological changes in volume and cross-sectional area (CSA) of lumbosacral region. The main objective of this study was to assess if CSA measurements of pelvic muscle will indicate muscle atrophy between asymptomatic and symptomatic sides in chronic LBP patients, as well as between right and left sides in healthy volunteers. In addition, inter-rater reliability for CSA measurements was examined. The study involved 71 chronic LBP patients and 29 healthy volunteers. The CSA of gluteus maximus, medius, minimus and piriformis were measured using the MRI manual segmentation method. Muscle atrophy was confirmed in gluteus maximus, gluteus minimus and piriformis muscle for over 50% of chronic LBP patients (p < 0.05). Gluteus medius showed atrophy in patients with left side pain occurrence (p < 0.001). Muscle atrophy occurred on the symptomatic side for all inspected muscles, except gluteus maximus in rater one assessment. The reliability of CSA measurements between raters calculated using CCC and ICC presented great inter-rater reproducibility for each muscle both in patients and healthy volunteers (p < 0.95). Therefore, there is the possibility of using CSA assessment in the diagnosis of patients with symptoms of chronic LBP.

Anatomical Variations between Sciatic Nerve and Piriformis Muscle on Computed Tomography Images from Radiotherapy Patients

Abstract Background: The sciatic nerve has several topographic variations, some of them in relation to the piriformis muscle. Such variations provide meaning insight while addressing pathologies related to sciatic nerve. Hence, this study was undertaken to check the anatomical variations of sciatic nerve using computed tomography (CT) images. Methodology: Thirty-three CT image series from pelvic radiotherapy patients were reviewed, with a DICOM viewer to assess the relation between the sciatic nerve and piriformis muscles, according to Beaton and Aston’s classification. Results: Thirty-three CT image sets and 66 gluteal regions were assessed. Type A of Beaton and Aston was found in 84.85% of the samples and Type B was found in 15.15%. No other types were found. Sixty-six percentage of the Type B classifications were bilateral. Conclusion: There is a 15.15% of topographical variation of sciatic nerve consistent with other studies. The use of medical images for this kind of study will allow more reliable results.

(064) Trigger Point Release of Post Partum Pudendal Compression Relieves Persistent Genital Arousal: Case Report

Abstract Introduction There is very little literature available on Persistent Genital Arousal Disorder (PGAD). Recent consensus definitions have emerged from the ISSWSH working group on PGAD to expel the myth that PGAD is merely in the minds of those who suffer from it. Dr. Goldstein, et al have published research and criteria for diagnosis, and management of this condition which can be a very distressing one. Novel Non-Invasive treatment modalities are needed for the management of PGAD to prevent distress, and/or unnecessary surgery, in these patients. Objectives To determine if local trigger point treatment of the area surrounding the Pudendal Nerve as it passes the piriformis muscle, will cause relief of Persistent Genital Arousal Disorder (PGAD) in a patient suffering for the 8 months since childbirth. Methods I present a case of a new mother who suffered from severe PGAD emerging following a precipitous and somewhat traumatic childbirth. The persistent arousal was distracting, upsetting, intolerable, and only somewhat (10-20%) temporarily mitigated by very regular self-stimulation, and also with regular pelvic floor physio, in a busy new mom, who had had no such concerns before-hand. She presented to me at 8 months post-partum, with an 8 month history of PGAD. Based on history of presenting illness, the source of problem was determined to be most likely in pelvis, and potentially caused by entrapment/compression of the Pudendal Nerve. Informed Consent was obtained to attempt trigger point release of the tissues surrounding the Pudendal Nerve posteriorly, as it enters the pelvis. Using a posterior approach, using a 27g 1.5cm bevelled needle, to an area cleaned by alcohol swab, micro-dissection release was performed of area surrounding tissue the Pudendal N as it passes the piriformis muscle. Patient reported immediate and sustained relief of symptoms. Results Trigger point needling to the tissue superior to, surrounding, and including the piriformis muscle via the posterior approach caused immediate and sustained relief of the patient’s symptoms. Repeat needle treatment to this area, alternating with physiotherapy for guided relaxation and release of surrounding tissues, resolved patient’s PGAD symptoms by &amp;gt;95% during treatment and &amp;gt;85% 1 year after treatment cessation. Conclusions Trigger Point needle treatment of tissues of the muscles and piriformis muscles relieved PGAD symptoms initially caused by Pudendal Nerve entrapment/compression second to precipitous childbirth. This non-invasive approach for immediate and sustained relief of Persistent Genital Arousal Disorder should be widely taught to practitioners of Sexual Medicine, and considered in patients with neurological causes for their distressing symptoms, arising from the pelvic area. Disclosure No.

Anatomical Variation of the Sciatic Nerve in Relation to the Piriformis Muscle: An MRI Study

Anatomical Variation of the Sciatic Nerve in Relation to the Piriformis Muscle: An MRI Study

Optimizing the Entry Point for Reconstruction Nailing of the Femur.

Varus after antegrade medullary nailing of the proximal femur is associated with worse outcomes. Anecdotally, a more medialized "trochiformis" entry is beneficial to avoid varus with valgus-bend (greater trochanteric entry) femoral nails. However, the optimal entry point remains unknown. The purpose of this study was to define the optimal entry point for reconstruction nailing. Using standing alignment radiographs from 51 patients, we templated the ideal entry point for straight and valgus-bend nails from three major manufacturers using TraumaCad software. We measured the distance from the tip of the trochanter to the ideal entry site for each nail. We compared piriformis (PF) with trochanteric (GT) entry for each company and across manufacturers. The mean greater trochanter offset from the femoral axis was 15.2 mm. The mean PF entry was 5.9 to 6.7 mm medial to the mean GT entry for each company's nail and was statistically distinct. No differences were observed in GT and PF entry points across manufacturers. Only 2 of 153 ideal GT entry points were lateral to the tip of the trochanter. An increased neck-shaft angle (NSA) and increased GT offset were correlated with a more medial ideal entry point. The ideal entry point for GT nails is similar across manufacturers and is medial to the tip of the greater trochanter; however, PF and GT entry sites remain distinct. During preoperative planning and when executing femoral nailing intraoperatively, it may also be important to consider the NSA and GT offset of a patient before committing to a certain entry point.

Association of Piriformis Thickness, Hip Muscle Strength, and Low Back Pain Patients with and without Piriformis Syndrome in Malaysia.

Low back pain is a serious threat to human health and the illness jeopardizes the human workforce and pressurizes the health system in the community. Low back pain might be related to piriformis syndrome (PS), which is a disorder presented as muscular spasm and hypertrophy that is strongly associated with piriformis thickness. Nevertheless, the relationship between piriformis thickness and morphological and functional changes of the gluteal muscles in PS remains unclear. This study aimed to investigate the association between the thickness, strength, and activation of piriformis and gluteus muscles (maximus and medius) among low back pain (LBP) patients with and without PS. This is a case-control study conducted at HSNZ and UiTM from 2019-2020. A total number of 91 participants (LBP + PS (n = 36), LBP - PS (n = 24), and healthy (n = 31)) were recruited in this study. Negative radiography, specific symptoms, and a positive PS test were applied for PS diagnoses. The thickness, strength, and activation of piriformis and gluteus muscles were measured using ultrasonography (USG) and a surface electromyogram, respectively. Resultantly, the one-way ANOVA test demonstrated no significant difference in piriformis thickness between LBP + PS and LBP - PS (p > 0.01). Piriformis thickness was inversely correlated with gluteus maximus strength (r = -0.4, p < 0.05) and positively correlated with gluteus medius activation (r = 0.48, p < 0.01) in LBP + PS. Stepwise linear regression for LBP + PS revealed a significant association between piriformis thickness and gluteus maximus strength (R = -0.34, accounted for 11% of the variance) and gluteus medius activation in prone lying with the hip in an externally rotated, abducted, and extended (ERABEX) position (R = 0.43, accounted for 23% of the variance). With the adjustment of age and gender, piriformis thickness, gluteus maximus strength, and gluteus medius activation in prone lying with hip ERABEX demonstrated a significant association, but no independent effect of age and gender was detected within the range. Meanwhile, a significant association between piriformis thickness and gluteus maximus thickness was observed (R = 0.44, accounted for 19% of the variance) in the LBP - PS group. These findings may assist to elucidate the actions and functions of piriformis and gluteus muscle in LBP with and without PS.

A Case-Control Study of 40 Patients with Piriformis Muscle Syndrome to Evaluate Diagnostic Findings Using Two-Dimensional Ultrasound and Shear Wave Elastography.

BACKGROUND Piriformis muscle syndrome (PMS) is a neuropathy caused by compression of the sciatic nerve by the piriformis muscle. This case-control study included 40 patients with PMS and aimed to evaluate the diagnostic findings using two-dimensional ultrasound and shear wave elastography (SWE), as non-invasive and cost-effective diagnostic methods. MATERIAL AND METHODS In order to evaluate the value of two-dimensional ultrasound diagnosis, a new imaging technique called shear wave elastography (SWE) was used in the screening of PMS, with a total of 40 PMS patients and 40 healthy individuals participating in our study. We analyzed the correlation and area under the curve (AUC) of changes in thickness (mm) and Young's modulus (kpa) of the bilateral piriformis muscle (PM). RESULTS We found that PM thickness and Young's modulus on the lesion sides were significantly higher in PMS patients than in controls (P<0.05). Also, we determined that there was a positive correlation between PM thickness and Young's modulus (r=0.454, P<0.05). Using two-dimensional ultrasonic diagnosis and the SWE technique, a specificity of 95.8% and sensitivity of 78.8% were demonstrated in the clinical diagnosis of PM. CONCLUSIONS Two-dimensional ultrasound with SWE technology has demonstrated its superior sensitivity and specificity in diagnosing PMS in the clinic.

A piriformis-preserving posterior approach reduces dislocation rate of the hemiarthroplasty in patients with femoral neck fracture

IntroductionThe posterior approach (PA) for hemiarthroplasty (HA) in patients with femoral neck fracture (FFN) has a high risk of dislocation; however, by preserving the piriformis muscle, the dislocation rate could be lowered considerably. The aim of this study was to compare the surgical complications of the piriformis-preserving posterior approach (PPPA) and the PA in patients with FNF treated with HA. MethodsOn 1 January 2019, the PPPA was introduced at two hospitals as the new treatment standard. The sample size was calculated based on a 5 percentage point dislocation reduction and 25% censoring; a sample of 264 patients per group was determined. An approximately 2-year inclusion period with 1-year follow-up was estimated, including a historical cohort from 2 years before the PPPA introduction. Data were retrieved from health care records and X-ray images from the hospitals’ administrative databases. Relative risk (RR) and 95% confidence intervals were calculated using Cox regression and adjusted for age, sex, comorbidity, smoking, surgeon experience and implant type. ResultsThere were 527 patients included in the study, of which 72% were women and 43% were above 85 years old. There were no baseline differences between the PPPA and PA groups in sex, age, comorbidity, body mass index, smoking, alcohol, mobility, length of surgery, blood loss or implant positioning, but there were differences in 30-day mortality, surgeon experience and implant type.The dislocation rate reduced from 11.6% in the PA group to 4.7% in the PPPA group (p = 0.004), with an RR of 2.5 (1.2; 5.1). The reoperation rate reduced from 6.8% with the PA to 3.3% with the PPPA (p = 0.022), with an RR of 2.1 (0.9; 5.2), and total surgery-related complications reduced from 14.7% with the PA to 6.9% with the PPPA (p = 0.003), with an RR of 2.4 (1.3; 4.4). InterpretationChanging from PA to PPPA in patients with FNF treated with HA resulted in a more than 50% reduction in dislocation and reoperation rates. This approach was easily introduced and may enable further lowering of dislocation rates through the sparing of all short external rotators.

Sacroiliac joint manipulation helps to improve pain pressure threshold in chronic piriformis syndrome: a 6-week randomized controlled trial US

Background: Piriformis syndrome (PS) has negative impact on the daily activities of the patients and lead to disability. There is an anatomical association of piriformis muscle with sacroiliac joint (SIJ). So manual therapy including manipulation of SI joint may be the option for relieving the symptoms of PS Objective: To investigate the effectiveness of Sacroiliac joint manipulation in improving pain pressure threshold in patients with chronic piriformis syndrome. Materials and Methods: A randomized clinical trial (NCT04603703) was conducted at Max Rehab and Physical Therapy Centre G8-Markaz, Islamabad, Pakistan. A total of n=30 patients were randomly divided into Experimental group (n=15) and control group (n=15). Both groups received conventional physical therapy including therapeutic ultrasound, moist hot pack, piriformis muscle stretching, myofascial release of paraspinal muscles, gluteal strengthening, sciatic neurodynamics. The experimental group additionally received sacroiliac joint manipulation. The outcome measures were pain, straight leg raise (SLR), pain pressure threshold and piriformis muscle length. The total time frame of the treatment was 3 days per week for 6 weeks and pre and post intervention assessment was done. Result: The mean age of participants was 40.46 ±10.513 years. Pain, SLR, pain pressure threshold and piriformis length was significantly improved (p&lt;0.001) in both the experimental and control group after 6th week intervention. Between group comparison there was no significant difference between the groups after 6-week intervention regarding the pain, SLR and piriformis muscle length, except pain pressure threshold which was significantly improved in experimental group as compared to control group (67.7±18.42 vs 52.51±15.26, p=0.020) . Conclusion: Addition of the sacroiliac joint thrust manipulation technique and conventional physical therapy alone were equally effective in decreasing pain intensity and normalizing length of Piriformis and Straight leg raise. But SIJ manipulation showed promising results on pain pressure threshold. Keywords: Articular, physical therapy modalities, piriformis muscle syndrome, pain threshold, range of motion, sacroiliac joint.

Deep posterior gluteal compartment block for regional anaesthesia of the posterior hip: a proof-of-concept pilot study.

Various regional anaesthesia approaches to branches of the anterior lumbar plexus have been proved effective in providing analgesia in hip surgery. However, some patients still experience significant residual posterior hip pain attributed to the posterior nerve supply of the hip. This not only suggests that anterior approaches may not always provide sufficient pain relief, but also that the blocking of major nerves supplying the posterior pericapsular region is needed. We present an ultrasound-guided technique to block all major nerves supplying the posterior capsule of the hip joint. The optimal target area was determined by ultrasound imaging, cross-sectional digitised anatomy, and cadaver research, and was found in the deep gluteal compartment. Furthermore, this posterior pericapsular deep-gluteal block was evaluated in two patients. The spread of dye in the cadaver was observed deep to the gluteus maximus and in between the quadratus femoris and piriformis muscles, and conformed to the presumed location during the ultrasound procedure. It included all major supplying nerves to the posterior hip capsule, that is the superior gluteal nerve, nerve to quadratus femoris and sciatic nerve. In both patients where this posterior pericapsular deep-gluteal block was applied the pain was substantially reduced (numeric rating scale: 4 to 1 and 7 to 1). We present a successful ultrasound-guided technique targeting the deep gluteal compartment to block all major nerves supplying the hip joint's posterior capsule. This posterior pericapsular deep-gluteal block can be applied as an additional block in hip surgery, with also a possible role in chronic hip pathology.

Piriformis Syndrome in Pre-monsoon, Monsoon, and Winter: An Observational Pilot Study.

Piriformis syndrome (PS) is a rare focal soft tissue rheumatic disease. Due to heavy rural work, we questioned whether PS was more prevalent in the rainy monsoon than in other seasons. In this pilot research, we studied the pattern of PS, the frequency of PS over the seasons, and whether there were typical preceding events. Methods: In this time-series descriptive study, PS cases diagnosed in a community-based clinic between January 2018 and December 2019 were enrolled. PS was diagnosed by clinical features and a 50% immediate pain relief from ultrasonogram-guided lidocaine (2%) injection in the piriformis muscle (PM). PS mimics were excluded. A total of 38 PS cases (11 males) were enrolled consecutively.In 2018, during dry winter (November-February), pre-monsoon (March-May), and rainy monsoon (June-October), nine, seven, and one PS cases were diagnosed, respectively; in 2019, the numbers were three, eight, and seven, respectively. Thus, over two years, 12 PS patients were diagnosed in dry winter, 15 in pre-monsoon, and eight in rainy monsoon. There was no correlation with the type of preceding events. There were no differences in the pattern of PS between the seasons. In this pilot study, over two years more new PS cases were observed in the pre-monsoon and dry winter than in the rainy season; this was not supporting our research question. There was no association with specific preceding events.

Variant Sciatic Nerve Anatomy in Relation to the Piriformis Muscle on Magnetic Resonance Neurography: A Potential Etiology for Extraspinal Sciatica

To assess the prevalence and clinical implications of variant sciatic nerve anatomy in relation to the piriformis muscle on magnetic resonance neurography (MRN), in patients with lumbosacral neuropathic symptoms. In this retrospective single-center study, 254 sciatic nerves, from 127 patients with clinical and imaging findings compatible with extra-spinal sciatica on MRN between 2003 and 2013, were evaluated for the presence and type of variant sciatic nerves, split sciatic nerve, abnormal T2-signal hyperintensity, asymmetric piriformis size and increased nerve caliber, and summarized using descriptive statistics. Two-tailed chi-square tests were performed to compare the anatomical variant type and clinical symptoms between imaging and clinical characteristics. Sixty-four variant sciatic nerves were identified with an equal number of right and left variants. Bilateral variants were noted in 15 cases. Abnormal T2-signal hyperintensity was seen significantly more often in variant compared to conventional anatomy (40/64 vs. 82/190; p = 0.01). A sciatic nerve split was seen significantly more often in variant compared to conventional anatomy (56/64 vs. 20/190; p < 0.0001). Increased nerve caliber, abnormal T2-signal hyperintensity, and asymmetric piriformis size were significantly associated with the clinically symptomatic side compared to the asymptomatic side (98:2, 98:2, and 97:3, respectively; p < 0.0001 for all). Clinical symptoms were correlated with variant compared to conventional sciatic nerve anatomy (64% vs. 46%; p = 0.01). Variant sciatic nerve anatomy, in relation to the piriformis muscle, is frequently identified with MRN and is more likely to be associated with nerve signal changes and symptomatology.

Sciatic Nerve Morphometry in the Gluteal Region in a Nigerian Population: An Anatomical Study

The sciatic nerve is frequently used in anesthesia, neurology, orthopedics, and rehabilitative medicine procedures. Due to its girth, the sciatic nerve is one of the human body's most often injured nerves. Unawareness of the structural differences of this nerve may be a contributing factor in damage. The purpose of the study is to evaluate the usual morphomety of the sciatic nerve and piriformis muscle. Lower limbs (N = 10) from Nigerian cadavers were chosen for this study's morphological examination and dissection. There were 8 males and 2 females in total. Using a computerized sliding calliper, the piriformis and sciatic nerve characteristics were examined and statistically analyzed.The right medial width (32.20±1.45mm) of the piriformis muscle was larger compared to the left (31.91±1.65mm). However, it was not so for lateral width of the piriformis muscle as the left was larger (17.35±0.25mm) compared to the right (17.09±0.17mm).The right length of superior piriformis border was larger (54.57±1.58mm) compared to the left (52.19±2.87mm). In comparison to the female specimens, the mean length of the sciatic nerve was substantially longer in the male specimens (p 0.05).

Anatomical Pitfalls of Excision of Deep Endometriosis Nodules of the Sciatic Nerve: A three-dimensional Reconstruction and Surgical Educational Video

To highlight the anatomical keys to safely performing an excision of deep endometriosis nodules of the sciatic nerve DESIGN: We present a didactic video combining an anatomical three-dimensional reconstruction of the pelvis using the Anatomage table and a surgical dissection video of the removal of deep endometriosis nodules of the left sciatic nerve [1]. The patient's approval was obtained. The patient consented that this surgical video be used for publication. Tertiary referral center. To reach this specific area, we must localize precise anatomical pitfalls [2,3]. Taking the external iliac vessels as an anatomical plane of reference, we can divide anatomical structures into lateral and medial. During the first step of the procedure, we open the latero-pelvic peritoneum covering the external iliac artery. This step allows the identification of the lateral anatomic keys. Lateral anatomic keys are represented by: (1) the genito-femoral nerve, an element which is superficially situated between the psoas muscle and external iliac artery, and (2) the obturator nerve (Video Still 1), which is deep and is located within the ilio-lumbar fossa. To enter it, a dissection between the psoas muscle and external iliac artery and vein must be performed. At this point, particular attention must be paid to the obturator artery that runs below the obturator nerve. In this fossa, the lumbosacral trunk is easily identified just below the obturator nerve; it lies at this level on the iliac bone. Then the opening of the posterior leaf of the broad ligament is realized. Therefore, we access the medial anatomic keys: (1) the ureter, and (2) the umbilico-artery trunk with the umbilical and uterine artery. In the opening of the posterior leaf, we can find the obturator nerve and lumbosacral trunk again. Finally, following the umbilical artery (that is the first branch of the internal iliac artery), we discover the internal iliac artery and vein. A very careful dissection of these vessels must be done to avoid big hemorrhages, which can be life-threatening [4-6]. In the plane below the internal iliac artery and vein, we access the sacral roots S1, S2, and S3 (Video Still 2), which join the lumbosacral trunk (lying on the piriformis muscle) to form the ischiatic nerve [7]. At this level, the ischiatic nerve exits through the infra-piriform foramen behind the ischiatic spine and sacrospinous ligament toward the gluteal area in an oblique way [8]. Two other elements may be seen: the pudendal nerve exiting the pelvis behind the sacrospinous ligament in a craniocaudal way and the posterior femoral cutaneous nerve. During this dissection, the autonomous system must be spared as usual to avoid functional sequelae. Removal of deep endometriosis nodules of sciatic nerves is a challenging procedure. Because few surgeries are specifically dedicated to the sciatic area, the specific anatomy of the region is poorly taught and known. However, pelvic anatomical knowledge is indispensable to the safe removal of nodules of sciatic nerves. The main advantage of this anatomical 3D reconstruction is the possibility of visualizing the deep pelvic anatomy in a laparoscopic position. Surgeons must be aware of both somatic and autonomous pelvic nerve anatomy within the retroperitoneal spaces and the great vessels surrounding them.

ANATOMICAL VARIATIONS OF SCIATIC NERVE - A CADAVERIC STUDY

Introduction: Sciatic nerve arises from lumbosacral plexus. It divides into tibial and common peroneal nerves from pelvis to popliteal region. The sciatic nerve usually exits from gluteal region below the piriformis muscle. Variations in course and level of division of sciatic nerve are well documented in the literature. Aim: The aim of the study is to evaluate for variations in relationship between the piriformis muscle and sciatic nerve and also the variations in the level of division of sciatic nerve. Materials and Methods: This study was done on 80 lower limbs of the 40 embalmed cadavers during routine anatomical dissections in the Department of Anatomy, Siddhartha Medical College, Vijayawada. Regions were dissected according to the guidelines and variations in sciatic nerve course and level of division were noted. Results: In this study we noted that relationships between sciatic nerve and piriformis muscle are of type A in 82.50%, type B in 8.75%, type C in 5.0%, type D in 2.5% and rare type G in 1.25%. With regard to the level of the division of sciatic nerve these are of type I in 28.75%, type II in 8.75%, type III in 6.25%, type IV in 3.75% and type V in 52.5%. Conclusion: The study establishes the variations in sciatic nerve relationship with piriformis muscle and its level of division in south Indian population. These are important to understand the variable symptoms in cases of sciatic nerve injury or compressions, complications during surgeries on gluteal region and also sciatic nerve block anesthesia.

A study of high division of sciatic nerve in human cadavers and its clinical significance

Background: Sciatic nerve is a mixed nerve which provide sensory and motor supply for skin and muscles of the lower limb by tibial and common peroneal nerve. Anatomical variations of sciatic nerve at high division have been reported by various authors. The path of the sciatic nerve is important while administration of intramuscular injection to prevent nerve injury and nerve blockage failure during anesthesia. This knowledge of high division helps in different surgical approach for sciatic nerve injury or hip dislocation. Aims and Objectives: The aim of the study was to describe incidences of high division variation of Sciatic nerve and different types in cadavers during routine dissection schedule. Materials and Methods: The study was conducted during routine dissection schedule in anatomy department for first MBBS students to observe sciatic nerve course in 30 gluteal regions from 15 adult cadavers fixed by formalin. Location of sciatic nerve in relation to piriformis muscle and its division whether in single nerve sheath or separate sheath and types was recorded. Results: In 12 cadavers (80%), sciatic nerve course found normal which leaves pelvis at inferior border of piriformis muscle and bifurcate in terminal branches tibial nerve and common peroneal nerve as it approaches at the apex of popliteal fossa. In 3 cadavers (20%), two male and one female, we found high division of sciatic nerve where terminal branches, tibial nerve, and common peroneal nerve leave the pelvis below piriformis separately in different sheaths. Conclusion: Knowledge of variations-related high division of sciatic nerve would help surgeons during different interventions related to sciatic nerve and for preventing further complications.

Anatomical variations between sciatic nerve and piriformis muscle on computed tomography images from radiotherapy patients

Anatomical variations between sciatic nerve and piriformis muscle on computed tomography images from radiotherapy patients

Магнитно-резонансно-томографическая анатомия половых нервов у мужчин зрелого возраста после выполнения оперативных вмешательств на органах малого таза

The work studied the magnetic resonance imaging (MRI) anatomy of the pudendal nerves in mature men who underwent surgery on pelvic organs. The study included 75 patients (30 patients in the first period of adulthood and 45 patients in the second period of adulthood). Thirty-seven patients underwent prostatectomy and 38 respondents underwent rectal resection. The single-trunk nature of the branching of the nerve, in which the pudendal nerve passes under the sacrospinous ligament, was found in the majority of patients (65.3%). The sources of formation of the pudendal nerves in 45 (60.0%) cases were the roots S2, S3 and S4, in 19 (25.3%) respondents the pudendal nerves were formed from the roots S2 and S4 and in 11 (14.6%) of respondents, the nerves originated from the S3 and S4 roots. The genital canals originate 22.5±3.2 mm below the ischial tuberosity and lie 39.8±9.5 mm anterior to it, the canals end at the level of the lower edge of the pubic symphysis 24.4±10.9 mm behind it. The average cross-sectional area of the genitals was 27.9±9.2 mm2. The average diameters of the pudendal nerve trunks at a level of 2 cm distal to the piriformis muscle were 4.63 mm, 1.85 mm, and 1.64 mm for the first, second, and third trunks, respectively. The average length of the pudendal nerve trunks before division into terminal branches was 25.23 mm. A comparison of the skeletotopic characteristics of the genital canals between patients with a conditional norm and patients after surgery on the pelvic organs demonstrated the presence of significant differences (p=0.023).

Find the Piriformis Muscle Easily: From Anatomical Landmark to Sonographic Target.

Find the Piriformis Muscle Easily: From Anatomical Landmark to Sonographic Target.

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.