Search

Variations of the peripheral nerve plexuses are important to those clinicians who diagnose and treat patients with pathology of their parts. During routine dissection, a postfixed lumbosacral plexus with a furcal nerve arising from L5, not L4, was discovered. In addition, the case was found to have a split L5 ventral ramus. Such a variation might become clinically significant during clinical presentations of radiculopathy. With a better understanding of the fucal nerve variation presented here, along with previously documented variations, the diagnostic and treatment procedures for atypical radiculopathy can be refined, reducing the rates of nerve injury and failed back surgery.

The approach to the sciatic plexus and lateral part of the sacrum is difficult. A subperitoneal anterolateral approach can be extended by sectioning the iliac bone above the acetabulum and lowering it toward the external part of the iliac wing and buttock. This transiliac anterolateral approach exposes the lumbosacral trunk, first sacral foramina and sciatic plexus to the origin of the sciatic trunk. Exposure can be extended upward by subperitoneal lumbotomy, downward by opening the ischiorectal fossa, or outward by trochanterotomy. This approach was used 18 times by one of the authors (FHD) for resection of 13 malignant tumors and 5 plexus releases. Procedure time was 3-6hours, with 500-4,000ml blood loss. The approach systematically enabled surgical objectives to be met. There was 1 septic complication that healed after debridement.

In the formation of nerves, variations are very common. They might be either pre- or post-fixed. The presence of neural roots with varying thicknesses or the absence of neural roots is also common. The main objective of the study was to observe the prefixed and postfixed pelvic nerves and their clinical sigbificance. Except for the obturator nerve, the pelvic nerves run along the posterior pelvic wall. The obturator nerve is located on the lateral side of the pelvic wall. Extraperitoneally, against the posterolateral walls of the pelvis, are located the pelvic nerves. The Lateral Femoral Cutaneous nerve, Femoral nerve, Genitofemoral nerve, Obturator nerve, and the Lumbosacral trunk are all somatic nerves in the pelvis. Variations in the level of these nerves' roots are relatively common, and these variations are significant for surgeons, orthopaedic surgeons, and neurosurgeons during various surgeries. The formation and level of division of parietal pelvic nerves showed a variety of variances, which are detailed in the study.

This study aims to evaluate the relation between the lumbosacral trunk (LT) and the sacro-iliac joint (SIJ). In forty anatomic specimens (hemipelves) a classical antero-lateral approach to the SIJ was performed. The SIJ was marked at the linea terminalis (reference point A). Reference point B was situated at the upper edge of the interosseous sacro-iliac ligament. The length of the SIJ (distance A to B) and the distance between point A and the ventral branch of the fourth (L4) and fifth (L5) lumbar spinal nerves at the linea terminalis were measured. The SIJ had a mean length of 58.0 mm. The ventral branch of L5 was located closer to the SIJ in very long SIJs (mean length: ≥ 6.5 cm; mean distance: 9.8 mm) compared to very short joints (≤ 5 mm; mean distance: 11.3 mm). For the ventral branch of L4, very long SIJs had a mean distance of 7 mm and very short joints an average distance of 9.7 mm between point A and the nerve branch. A safe zone of approximately 1 cm to 2 cm (anterior to posterior) is present on the sacral surface (lateral to medial) for safe fixation of plates during anterior plate stabilization of the SIJ. Pelves with a shorter dorsoventral diameter of the most superior part of the SIJ apparently give more space for inserting plates.

Variations in the course of the lumbar plexus and lumbosacral trunk have been explored with respect to variant nerve roots being indicated in atypical sciatic pain. Typically, the furcal nerve emerges from the L4 nerve root, with a single contribution. However, we report a case where the furcal nerve was found to arise not only from the L4 nerve but also from the obturator nerve. This anatomical variation is explored in terms of its clinical significance and implications in lumbar and sacral plexus associated procedures.

The “lumbar” component of the lumbosacral plexus is derived from part of the L4 ventral ramus and all of the L5 ventral ramus. Together, these two structures form the lumbosacral trunk. This structure enters the pelvis over the ala of the sacrum. This chapter details the detailed anatomy of the lumbosacral trunk.

Reading magnetic resonance neurography (MRN) of the sacral plexus is challenging owing to the complicated anatomy of the pelvis and to the small caliber and complex course of many nerves in this region. Although MRN can identify the roots of the sacral plexus and its tributaries, this examination remains difficult to perform and requires competence, high-resolution sequences, and a deep knowledge of the normal imaging anatomy. The aim of this chapter is to provide a comprehensive review of the imaging anatomy of the sacral plexus to help in interpreting MRN images correctly. We will describe the anatomy on MRN of the lumbosacral trunk, first to fourth sacral nerve roots, superior and inferior gluteal nerves, sciatic nerve, lateral femoral cutaneous nerve, peroneal nerve, tibial nerve, and pudendal nerve.

A cat was anaesthetised with midazolam and alfaxalone for a pelvic limb amputation due to a metatarsal fracture complicated with soft tissue necrosis. The femoral nerve and lumbosacral trunk were blocked with ropivacaine 0.75 per cent using a combined ultrasound/nervestimulation-guided approach. Anaesthesia was maintained with end-tidal concentrations of isoflurane between 1 per cent and 1.1 per cent. Vital parameters were stable during anaesthesia although moderate hypothermia (33.6°C–35.5°C) was encountered. The lateral cutaneous branch of the femoral nerve was desensitised with lidocaine 2 per cent at the end of the surgical procedures. The cat recovered well from anaesthesia and received meloxicam 0.05 mg/kg daily for postoperative pain treatment. Repeated evaluations using a composite pain scale showed values compatible with low probability of pain during the following 48 hours. Only one dose of methadone (0.2 mg/kg) was given. The combined femoral nerve and lumbosacral trunk block provided optimal intraoperative antinociception and postoperative pain relief.

The lumbosacral trunk consists of the ventral rami of L5 and a portion of L4. Before it merges with the L4 component, the L5 ramus passes through the lumbosacral tunnel, a passageway of bone and ligament at the superolateral margin of the sacral ala that can occasionally be a source of extraforaminal L5 nerve entrapment. These elements of the lumbosacral plexus traverse the surgical field of the lateral approach, and a surgeon must take care to avoid them in order to prevent postoperative radicular complications.

The purpose of this study is to observe the origin, course, length, diameter and termination of the ilio-lumbar artery (ILA) and its variations in south Indian population. The study was carried out in 34 sides in 19 cadavers (R-18, L-16) used for routine dissection for undergraduate students during the period of 2017–2018 in Department of Anatomy, JIPMER, Puducherry. On each side of the pelvis, the origin, length, diameter, course of the ILA and its relations to the surrounding anatomical structures was observed and documented. Out of 34 formalin-fixed pelvis halves of human cadavers, the ILA originated from the common iliac artery (CIA), the trunk of the internal iliac artery (IIA) and posterior division of IIA in around 0%, 61.76%, and 38.23% of the cases, respectively. In all the cadavers, the ILA passes in between the obturator nerve anteriorly and the lumbosacral trunk posteriorly and ILA terminates by giving iliac and lumbar arteries medial to the psoas major muscle. In our study, we observed that the mean distance between the origin of ILA and the bifurcation of the CIA is significantly less than the study done previously. The knowledge about the variations in the origin, course, length, diameter, and termination of ILA is very important to the surgeon to avoid iatrogenic injury during surgeries in lumbosacral region and moreover, it will be easy to access the ILA for clamping or embolization. A similar study can be done with more sample size in different population to increase the knowledge base regarding ILA anatomy.

Study Objective Our objective is to review the anatomic course, sensory and motor functions, and approach to dissection of important pelvic nerves encountered during advanced gynecologic laparoscopy. Design Using annotated intraoperative footage, we illustrate surgical approaches to safe dissection of the following pelvic nerves: Ilioinguinal, iliohypogastric, lateral femoral cutaneous, femoral, genitofemoral, obturator, sciatic, hypogastric and pudendal nerves, lumbosacral trunk and sacral nerve roots. Setting Patients were placed in dorsal lithotomy position with legs in Yellowfin stirrups. The umbilicus was used for camera port placement, and three accessory ports were placed (in the bilateral lower quadrants and a second to the left of the umbilicus). Patients or Participants Patients requiring dissection of the aforementioned nerves for surgical treatment of deep infiltrating endometriosis, adhesiolysis, or treatment of pudendal neuralgia were selected. Interventions N/A. Measurements and Main Results N/A. Conclusion Surgeons must have a comprehensive understanding of pelvic anatomy and comfort operating in deep pelvic spaces in order to minimize risk of inadvertent nerve injury. A systematic approach to nerve dissection enables adequate exposure of the operative field and safe space for lysis of adhesions, excision of endometriosis, and surgical treatment of pelvic pain syndromes.

Introduction: Lumbar plexus involves the L1 - L5 spinal segments for the formation of the nerves which supply parts of the abdominal wall, pelvis and the upper part of the thigh (both sensory and motor). Our aim in this study was to compile all the rare variations found in a single cadaver, which is of the rarest possible kind. Methods: During the dissection of the abdomen and pelvis in approximately 70 year old cadaver, there were multiple variations observed in the anatomy of the lumbar plexus. The entire region was cleaned for visibility of the variations and all those were clearly documented for compiling purpose. Results: The following variations in the formation of the lumbar and sacral nerves were observed. 1. The genitofemoral nerve bifurcated at a higher level; genital branch of genitofemoral nerve gave branches to the anterior abdominal wall muscles, 2. A communicating branch was given from the lateral cutaneous nerve of thigh to the medial cutaneous nerve of thigh, 3. A muscular branch was given from femoral nerve to psoas major, 4. There was absence of contribution of L4 spinal nerve in the formation of the lumbosacral trunk, and 5. Lumbosacral trunk gave communicating branches to the femoral and obturator nerves. Most of the variations found were rare and finding all the above said variations in a single cadaver is even rare. Conclusion: Knowledge of the normal anatomy and any possible variations would help the clinicians and surgeons dealing with this region and avoid possible complications beforehand.

Aim To determine the anatomical organization and somatic axonal components of the lumbosacral nerves in female rabbits. Methods Chinchilla adult anesthetized female rabbits were used. Anatomical, electrophysiological, and histological studies were performed. Results L7, S1, and some fibers from S2 and S3 form the lumbosacral trunk, which gives origin to the sciatic nerve and innervation to the gluteal region. From S2 to S3 originates the pudendal nerve, whose branches innervates the striated anal and urethra sphincters, as well as the bulbospongiosus, ischiocavernosus, and constrictor vulvae muscles. The sensory field of the pudendal nerve is ∼1800 mm2 and is localized in the clitoral sheath and perineal and perigenital skin. The organization of the pudendal nerve varies between individuals, three patterns were identified, and one of them was present in 50% of the animals. From S3 emerge the pelvic nerve, which anastomoses to form a plexus localized between the vagina and the rectum. The innervation of the pelvic floor originates from S3 to S4 fibers. Conclusions Most of the sacral spinal nerves of rabbit are mixed, carrying sensory, and motor information. Sacral nerves innervate the hind limbs, pelvic viscera, clitoris, perineal muscles, inguinal and anal glands and perineal, perigenital, and rump skin. The detailed description of the sacral nerves organization, topography, and axonal components further the knowledge of the innervation in pelvic and perinal structures of the female rabbit. This information will be useful in future studies about the physiology and physiopathology of urinary, fecal, reproductive, and sexual functions.

The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is variable. The variations of the arterial course in relation to the lumbosacral plexus have focused on statistical analysis, and it is limited arterial diversity. In this study, we investigated the positional relation between the SGA and the furcal nerve (FN): guide to segmentation of the lumbosacral plexus, arising from the L4, ie, the contribution to the femoral nerve, obturator nerve, and lumbosacral trunk. We could classify the pathway of the SGA into three types based on its positional relation to the FN. The SGA courses under the ramus from which the FN originates (Type A), under the ramus one segment below the origin of the FN (Type B), or between the obturator nerve and the lumbosacral trunk (Type C). The SGA pathway in Types A and B showed a cranial or caudal shift along with cranial or caudal deviation of the FN. In summary, the variation in the SGA pathway was correlated with cranial or caudal shift of the FN. Our findings indicate that variations of the SGA pathway are associated not only with arterial transformation, but also with diversity of the lumbosacral plexus.

Schwannomais, usually, benign tumor of nerve sheath that occurs evenly along the spinal cord. Intra-pelvic schwannoma is very rare entity that may arise from lumbosacral nerve roots or from sciatic nerve. Radicular pain of the lower limb as a presenting symptom of pelvic schwannoma is extremely rare. In the current report, the patient is presented with a right sided L5 radicular pain typical of lumbar discopathy. Interestingly, a herniated lumbar disc was noted on lumbosacral magnetic resonance imaging (MRI). In pre-operative studies a large pelvic mass was detected in the right pre-sacral area with solid and cystic components consistent with schwannoma. The patient underwent a low midline laparotomy to evacuate the retroperitoneal mass. Uniquely, we found the tumor to be arisen from lumbosacral trunk not from a root or peripheral nerve. Most cases with intra-pelvic schwannoma present so late with vague abdominal and pelvic discomfort or pain, low back pain, urinary and bowel symptoms because of compressive effect of the tumor, or incidentally following gynecologic work-ups; So, these patients are mostly referred to gynecologists and urologists. A neurosurgeon should have a high degree of suspicion to diagnose such an entity among his or her patients presented with pains typical for discopathy.

In this case study we present new evidence of a piriformis muscle variant inserting onto the hip joint capsule similar to that described by Tubbs and Salter. The variant was also atypical in that it originated medial to the first anterior sacral foramina and therefore obscured the union of the S1 nerve root and lumbosacral trunk. We believe this is the first instance that this variant has been noted.

Introduccion . Las ramas del plexo sacro juegan un rol importante en la inervacion motora y sensitiva del miembro inferior. En operaciones de la medula espinal observamos diversas variedades y nos motivo para iniciar este estudio dirigido a determinar la formacion del plexo sacro desde la emergencia de cada raiz en los agujeros sacros hasta la formacion de sus ramas terminales. Material y metodo . Se examinaron 100 plexos sacros en 50 cadaveres adultos con el proposito de determinar incidencia de las variaciones nerviosas. Tambien consideramos el recorrido de sus ramas, sus anastomosis y grosor. Destacamos las particularidades de la inervacion motora en el diagnostico, ademas de la complejidad y variaciones anatomicas. Resultados . En general observamos 3 raices sacras con la participacion de S4 y el tronco lumbo-sacro de L4 y L5, y 4 nervios sacros. Habitualmente se observo un recorrido ascendente doble de la raiz S1, mientras que para las otras raices la emergencia doble no fue comun. El tronco lumbosacro se engroso en 19 casos. La division muy alta del nervio ciatico (en la pelvis menor) se observo en 2 casos. El nivel de ramificacion de los otros nervios dependio del tipo de plexo. Conclusion . Nuestro estudio revelo variaciones relativamente frecuentes y variaciones anatomicas extraordinarias en la formacion de las raices nerviosas y la ramificacion del plexo sacro. El conocimiento detallado de estas variaciones es util para el propio diagnostico y el tratamiento quirurgico de las lesiones del plexo sacro y el dolor idiopatico. Introduction . Branches of sacral plexus play an important role in the motor and sensory innervation of the lower limb. Various variations observed during the spinal operations have motivated us to start the study aimed on determination of the sacral plexus formation from its exit of particular roots from sacral foramina up to their formation into terminal branches. Material and method. One hundred sacral plexuses have been examined on 50 adult cadavers for a purpose to find out an incidence of its neural variations. We have considered also the course of their branches, the anatomoses and their thickness. We highlighted the motor innervation particularities in the relation to the diagnosis besides its anatomical complexity and variability. Results . Commonly were observed 3 sacral roots with the share of S4 and lumbosacral trunk of L4 and L5 and 4 sacral nerves. Doubled ascending course of S1 root was often observed, by the other sacral roots the doubled exit was not so frequent. Lumbosacral trunk was thickened in 19 cases. Very high division of the sciatic nerve (in the lesser pelvis) was observed in 2 cases. The branching off level of other nerves depended on the plexus type. Conclusion. Our study revealed a relatively frequent variabilities and described some extraordinary anatomical variations in the formation of nerve roots and branches of the sacral plexus. The detailed knowledge of these variabilities is useful for the proper diagnostics and surgical treatment of the sacral plexus injuries and unexplainable paient‘s complaints.

Endometriosis is an important disorder which affects women in the childbearing age group. In addition to the commonly observed intrapelvic sites, it can very rarely affect extrapelvic location such as the sciatic nerve. We describe an uncommon case of sciatic endometriosis leading to gross muscular atrophy and foot drop. The patient additionally had perineural extension of endometriosis along the ipsilateral lumbosacral trunk and coexisting intrapelvic endometrial implants in retrocervical area, uterosacral ligament, and urinary bladder wall.

Introduction The S2 alar-iliac (S2AI) screw is a modification of the traditional iliac fixation technique and has surgical and biomechanical benefits. However, there are significant regional neurovascular structures along the path of such screws. Therefore the current anatomic study was performed to better elucidate these relationships. Methods Using fluoroscopy, S2AI screws were placed in 2 adult cadavers through a standard posterior midline exposure. The screw insertion point was placed 10 mm lateral to a line bisecting the S1 and S2 foramina, adjacent to the sacroiliac joint. Using 30- to 40-degree lateral angulation from the midline and 20- to 30-degree caudal angulation, a pedicle probe was directed toward the anterior inferior iliac spine. The final trajectory was positioned to sit 1−2 cm superior to the greater sciatic foramen. Lastly, the screws and surrounding bone were drilled in order to visualize both lateral and medial neurovascular relationships. Results Removing the bone around the S2AI-screw illustrated the close relationship to the medial (internal) neurovascular structures including the obturator nerve, lumbosacral trunk, sacral plexus and, specifically, the S1 ventral ramus and iliac vein and artery. By removing the outer cortex of the ilium, the close relationship to the superior gluteal artery, vein, and nerve was observed. In addition, we were able to identify the proximity to the iliopsoas muscle and internal iliac vessels. Conclusions A comprehensive knowledge of the surrounding neurovascular anatomy relevant to S2AI screw placement can decrease patient morbidity and allow spine surgeons to better diagnose potential postoperative complications.

Study Objective To demonstrate the laparoscopic approach to malformed branches of the vessels entrapping the nerves of the sacral plexus. Design A step-by-step explanation of the surgery using video (educative video) (Canadian Task force classification II). The university's Ethics Committee ruled that approval was not required for this video. Setting Kocaeli Derince Education and Research Hospital, Kocaeli, Turkey. Patient A 26-year-old patient who had failed medical therapy and presented with complaints of numbness and burning pain on the right side of her vagina and pain radiating to her lower limbs for a period of approximately 36 months. Intervention The peritoneum was incised along the external iliac vessels, and these vessels were separated from the iliopsoas muscle on the right side of the pelvis. The laparoscopic decompression of intrapelvic vascular entrapment was performed at 3 sites: the lumbosacral trunk, sciatic nerve, and pudendal nerve. The aberrant dilated veins were gently dissected from nerves, and then coagulated and cut with the LigaSure sealing device (Medtronic, Minneapolis, Minn). Measurements and Main Results The operation was completed successfully with no complications, and the patient was discharged from the hospital 24 hours after the operation. At a 6-month follow-up, she reported complete resolution of dyspareunia and sciatica (visual analog scale score 1 of 10). Conclusion A less well-known cause of chronic pelvic pain is compression of the sacral plexus by dilated or malformed branches of the internal iliac vessels. Laparoscopic management of vascular entrapment of the sacral plexus has been described by Possover et al 1 , 2 and Lemos et al [3] . This procedure appears to be feasible and effective, but requires significant experience and familiarity with laparoscopy techniques and pelvic nerve anatomy.

Objective Sacroiliac joint pain can be disabling and recalcitrant to medical therapy. The innervation of this joint is poorly understood, especially its anterior aspect. Therefore, the present cadaveric study was performed to better elucidate this anatomy. Methods Twenty-four cadaveric sides underwent dissection of the anterior sacroiliac joint, with special attention given to any branches from regional nerves to this joint. Results No femoral, obturator, or lumbosacral trunk branches destined to the anterior sacroiliac joint were identified in the 24 sides. In 20 sides, one or two small branches (less than 0.5 mm in diameter) were found to arise from the L4 ventral ramus (10%), the L5 ventral ramus (80%), or simultaneously from both the L4 and L5 ventral rami (10%). The length of the branches ranged from 5 to 31 mm (mean, 14 mm). All these branches arose from the posterior part of the nerves and traveled to the anterior surface of the sacroiliac joint. No statistical significance was found between sides or sexes. Conclusions An improved knowledge of the innervation of the anterior sacroiliac joint might decrease suffering in patients with chronic sacroiliac joint pain.

Fused real-time ultrasound and magnetic resonance imaging (MRI) may be used to improve the accuracy of advanced image guided procedures. However, its use in regional anesthesia is practically nonexistent. In this randomized controlled crossover trial, we aim to explore effectiveness, procedure-related outcomes, injectate spread analyzed by MRI, and safety of ultrasound/MRI fusion versus ultrasound guided Suprasacral Parallel Shift (SSPS) technique for lumbosacral plexus blockade. Twenty-six healthy subjects aged 21–36 years received two SSPS blocks (20 mL 2% lidocaine-epinephrine [1 : 200,000] added 1 mL diluted contrast) guided by ultrasound/MRI fusion versus ultrasound. Number (proportion) of subjects with motor blockade of the femoral and obturator nerves and the lumbosacral trunk was equal (ultrasound/MRI, 23/26 [88%]; ultrasound, 23/26 [88%];p=1.00). Median (interquartile range) preparation and procedure times (s) were longer for the ultrasound/MRI fusion guided technique (686 [552–1023] versus 196 [167–228],p<0.001and 333 [254–439] versus 216 [176–294],p=0.001). Both techniques produced perineural spread and corresponding sensory analgesia from L2 to S1. Epidural spread and lidocaine pharmacokinetics were similar. Different compartmentalized patterns of injectate spread were observed. Ultrasound/MRI fusion guided SSPS was equally effective and safe but required prolonged time, compared to ultrasound guided SSPS. This trial is registered with EudraCT (2013-004013-41) and ClinicalTrials.gov (NCT02593370).

To assess the quality and accuracy of metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) for the diagnosis of lumbosacral neuropathies in patients with metallic implants in the pelvis. Twenty-two subjects with lumbosacral neuropathy following pelvic instrumentation underwent 1.5-T MARS MRI including optimized axial intermediate-weighted and STIR turbo spin echo sequences extending from L5 to the ischial tuberosity. Two readers graded the visibility of the lumbosacral trunk, sciatic, femoral, lateral femoral cutaneous, and obturator nerves and the nerve signal intensity of nerve, architecture, caliber, course, continuity, and skeletal muscle denervation. Clinical examination and electrodiagnostic studies were used as the standard of reference. Descriptive, agreement, and diagnostic performance statistics were applied. Lumbosacral plexus visibility on MARS MRI was good (4) or very good (3) in 92% of cases with 81% exact agreement and a Kendall’s W coefficient of 0.811. The obturator nerve at the obturator foramen and the sciatic nerve posterior to the acetabulum had the lowest visibility, with good or very good ratings in only 61% and 77% of cases respectively. The reader agreement for nerve abnormalities on MARS MRI was excellent, ranging from 95.5 to 100%. MARS MRI achieved a sensitivity of 86%, specificity of 67%, positive predictive value of 95%, and negative predictive value of 40%, and accuracy of 83% for the detection of neuropathy. MARS MRI yields high image quality and diagnostic accuracy for the assessment of lumbosacral neuropathies in patients with metallic implants of the pelvis and hips.

Deviations detected during spinal operations have motivated us to start research related to variations of lumbosacral plexus formation. Aim of this work was to find out deviations of its formation from ascension of particular roots from foramen invertebrale and foramina sacralia up to formation of terminal branches. SET: One hundred lumbosacral plexi have been examined in 50 adult cadavers for a purpose to find out an incidence of neural variations. We have observed participation of Th(12) root, L(4) and L(5) roots in its formation, as well as various deviations from ascension of particular plexiform roots up to their ending branches. For lumbal plexus, we have observed four nerve roots and six lumbal nerves; for sacral one, three sacral roots with a share of S(4) and lumbosacral trunk formed of L(4) and L(5) roots and four sacral nerves. We have considered also their course, anastomoses and thickness. We highlight motoric innervation particularities in relation to diagnostics besides anatomical complexity and variability.Variations on the level of neural roots were common, nerve formations were uncommon. Thickness of neural roots, formation or their absence were dependent on the type of plexus, particularly in sacral area. For lumbal plexus, L(1) root was the thinnest and L(4) root was the thickest. L(3) root was the thickest in six cases. Fifth lumbal root usually completely filled foramen invertebrale. We have observed double ascension of L(4) root from foramen invertebrale in 25 cases and plexiform in five cases. In other cases it was branched in various distance following ascension from foramen invertebrale. Plexiform ascension of L(3) root along with L(4) root was present in two cases. Double ascension of L(3) root was present in four cases. L(2), L(3) along with L(5) roots were doubled in two cases. Iliohypogastric nerve was the longest, ilioinguinal was the thinnest and nervus femoralis was the thickest. Changes in sacral plexus on the level of neural roots have been observed 41-times. Double ascension of L(5) root was present in eight cases and plexiform in four cases. Double S(1) root at ascension from foramina sacralia was present 16 times, S(2) 8 times, S(3) once and S(1) along with S(2) 4 times. S(1), S(2) and S(3) roots were branched in various distance following ascension from foramina sacralia in 15 cases. Truncus lumbosacralis was thickened in 19 cases, a share from L(4) root was thicker as L(5) root in 11 cases. Low level of connection between truncus lumbosacralis and S(1) root was observed in 10 cases. Nervus ischiadicus has branched into tibial and peroneal portions already in minor pelvis in two cases. The level of distance of n. (nervus) gluteus superior, n. gluteus inferior, n. cutaneus femoris posterior and n. pudendus was dependent on the plexus type.This study enabled us to find out and to describe extraordinary anatomical deviations in formation of neural roots and nerves of lumbal and sacral plexus, undescribed yet.

Objectives of this study include identification of lumbosacral venous variations, designation of a critical area of dissection for surgical exposure, and comparison between both male/female and right/left-sided anatomy. Attempts were made to provide anatomic nomenclature that accurately describes these structures. Thirty-eight iliolumbar venous systems in 20 cadavers (11 females/9 males) were dissected. Each system was identified as one of three patterns of variation: common venous trunk (combining ascending lumbar and iliolumbar venous systems) with distal veins, common venous trunk without distal veins, and venous systems without a common venous trunk. Dimensions including distances to the inferior vena cava (IVC) confluence, the obturator nerve, and the lumbosacral trunk, and venous stem length were obtained to aid surgical dissection. Differences between males and females and those between right and left sides were compared. Anterior lumbosacral venous variations could be organized into three groups. A Type 1 venous system (common venous trunk with distal veins) was most common (53% of systems). The anatomical name "lateral lumbosacral veins" adequately describes the anatomical location of these veins and does not assume a direction of venous flow or the lack of individual distal veins. A critical area bordered by the obturator nerve anteriorly, the psoas muscle laterally, the spinal column medially, and sacrum posteriorly within 8.2 cm of the IVC confluence should be defined to adequately dissect the lateral lumbosacral veins. Differences in male and female lateral lumbosacral venous anatomy do not alter surgeon's approach to the anterior lumbar spine.

Objective To study the anatomy of veins of the lower lumbar spine and provide the anatomic basement for laparoscopic lumbar surgery. Methods A total of 15 formaldehyde-preserved cadavers were studied with special attention to the variety and surrounding structure of ascending lumbar vein (ALV) and iliolumbar veins (ILV), and their relationship with lumbar plexus. Results ALV and ILV can be found on every sides, which have four variants including separate entry and common entry. The ascending vein and iliolumbar vein separately enter common iliac vein in 18 cases, and as a common stem enter the common iliac vein in 12 cases. Retracting common iliac vein medially both the ascending lumbar and the iliolumbar veins are always at risk of avulsion on exposure of the disc space. The injury of obturator nerve and lumbosacral trunk of lumbar plexus should be avoided. Conclusions Awareness of these anatomic variation can prevent the hemorrhage and be helpful for the surgeon in performing a careful ligation of these veins before medial retraction of the common iliac vein. Our findings emphasize the need for proper dissection of ALV and ILV before ligature during exposure of the lower lumbar spine.

Sacral plexus is formed by the lumbosacral trunk (part of the fourth and all the fifth lumbar ventral ramus), the first to third sacral ventral rami and part of the fourth sacral ventral ramus. It forms the sciatic nerve, nerve to the quadratus femoris, nerve to the obturator internus, nerve to the piriformis, superior gluteal nerve, inferior gluteal nerve, posterior cutaneous nerve of thigh, perforating cutaneous nerve, and pudendal nerve. Sacral plexus nerve injuries are common, occurring directly by trauma (as a complication of pelvic and orthopedic surgeries and nerve blocks or accidental) or indirectly by ischemia secondary to stretch or poor perfusion. Injury to these nerves causes distress and disability and may lead to permanent motor and/or sensory loss. This chapter studies the anatomy of the nerves of the sacral plexus in detail and will highlight the context, mechanism, frequency and outcome following injury. Awareness of this anatomy, particularly in the context of injury may reduce the frequency of sacral plexus nerve injuries.

Adequate (wide or marginal and uncontaminated) margins and reconstruction are difficult to achieve when performing an internal hemipelvectomy for bone sarcomas involving the sacroiliac joint. We evaluated whether adequate surgical margins could be achieved and if functional outcomes could be predicted based on the type of resection and reconstruction. Forty patients had resections of the sacroiliac joint. Vertical sacral osteotomies were through the sacral wing (n = 2), ipsilateral sacral foramina (n = 27), sacral midline (n = 9), or contralateral foramina (n = 2). Iliac resections were Type I, Type I-II with partial or total acetabular re-section, or Type I-II-III. Surgical margins were adequate in 28 of 38 patients (74%), two (7%) of whom experienced local recurrence, compared with seven of 10 (70%) patients with inadequate margins. Reconstruction consisted of restoring continuity between the spine and pelvis. Resection of the entire acetabulum and removal of the lumbosacral trunk were the two main determinants of function, as assessed using the Musculoskeletal Tumor Society score. There were no life-threatening or function-threatening complications. Internal hemipelvectomy with a limb salvage procedure can be achieved with adequate surgical margins in selected patients. Functional outcomes can be predicted based on the type of resection and reconstruction, which helps the surgeon plan the procedure and inform the patient.

The principal author was confronted few years ago with the case of a 38-year-old woman with a 5-month history of ill-defined L5 sciatic pain that was referred to an orthopaedic department for investigation and eventual surgical treatment for what was suspected to be herniated disc-related sciatica. Removal of her enlarged uterus found unexpectedly close to the sacroiliac joint upon lumbar MRI abolished her symptoms. Review of the literature showed that the lumbosacral trunk is vulnerable to pressure from any abdominal mass originating from the uterus and the ovaries. Physiological processes in the female patient and gynaecological diseases may be the source of sciatica, often not readily searched for, leading to fruitless investigations and surgical treatments. The aim of the paper is to highlight gynaecological and obstetrical causes of sciatica and sciatica-like symptoms. To prevent unproductive expenses and morbidity, a thorough gynaecological examination should be done even though neurological examination may be suggestive of a herniated intervertebral disc, and the cyclic pattern of pain related to menses should be routinely asked for.

Mapping studies of pain elicited by injections into the sacroiliac joints (SIJs) suggest that sacroiliac joint syndrome (SIJS) may manifest as low back pain, sciatica, or trochanteric pain. Neither patient-reported symptoms nor provocative SIJ maneuvers are sensitive or specific for SIJS when SIJ block is used as the diagnostic gold standard. This has led to increasing diagnostic use of SIJ block, a procedure in which an anesthetic is injected into the joint under arthrographic guidance. However, several arguments cast doubt on the validity of SIJ block as a diagnostic gold standard. Thus, the effects of two consecutive blocks are identical in only 60% of cases, and the anesthetic diffuses out of the joint in 61% of cases, often coming into contact with the sheaths of the adjacent nerve trunks or roots, including the lumbosacral trunk (which may contribute to pain in the groin or thigh) and the L5 and S1 nerve roots. These data partly explain the limited specificity of SIJ block for the diagnosis of SIJS and the discordance between the pain elicited by the arthrography injection and the response to the block. The limitations of provocative maneuvers and SIJ blocks may stem in part from a contribution of extraarticular ligaments to the genesis of pain believed to originate within the SIJs. These ligaments include the expansion of the iliolumbar ligaments, the dorsal and ventral sacroiliac ligaments, the sacrospinous ligaments, and the sacrotuberous ligaments (sacroiliac joint lato-sensu). They play a role in locking or in allowing motion of the SIJs. Glucocorticoids may diffuse better than anesthetics within these ligaments. Furthermore, joint fusion may result in ligament unloading.

We report a case of L5 radiculopathy secondary to intrapelvic placement of an acetabular screw impinging on the lumbosacral trunk. A 43-year-old man underwent revision of an uncemented total hip replacement to a custom-made femoral component and uncemented cup. He subsequently developed hip pain, dysesthesia, and L5 radiculopathy. Spiral computed tomography (CT) and plain radiographs raised the possibility of an acetabular screw abutting the neurovascular bundle within the pelvis. Operative removal of the intrapelvic portion of the screw resulted in the immediate relief of the patient's radicular symptoms. This case report highlights the importance of the positioning of intrapelvic screws and the need for an anatomic awareness of the structures at risk during acetabular screw placement.

The pedicled intercostal neurovascular island flap is a useful flap due to its pedicle length, skin pedicle size and possibility for sensation. We present our experience of using this flap for lumbosacral trunk reconstruction in four patients.

There are many conflicting theories regarding the mechanism and prognosis of acute foot drop during labor. We report seven women who had arrested labor and foot drop. Six had short stature and one had a large newborn. All had weakness of ankle dorsiflexion, eversion, and inversion, and sensory loss in the L-5 dermatome. Superficial peroneal sensory nerve action potentials (SNAPs) were small or absent in six patients, and the sural SNAP was attenuated in one. Peroneal compound muscle action potential (CMAP) amplitude (recording from extensor digitorum brevis) was low in five, whereas the tibial CMAP was normal in all patients. Peroneal CMAP amplitude (recording from the tibialis anterior) was normal in three and small in three. Needle electromyography revealed decreased recruitment and fibrillation potentials in L-5-innervated muscles, mostly below the knee. We conclude that intrapartum foot drop occurs mostly in short women and is caused by lumbosacral trunk compression by the fetal head at the pelvic brim. The primary pathology is predominantly demyelination and recovery is complete in up to 5 months.