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We describe the anatomy of the uterosacral ligament with respect to the sacral plexus. In six adult female embalmed cadavers, we identified the uterosacral ligament and its lateral nerve relations. Using the ischial spine as the starting point and measuring along the axis of the uterosacral ligament, we noted that the S1 trunk of the sacral plexus passes under the ligament 3.9 cm [95% confidence interval (CI), 2.1-5.8 cm] superior to the ischial spine. The S2 trunk passes under the ligament at 2.6 cm (95% CI; 1.5, 3.6 cm), the S3 trunk passes under the ligament at 1.5 cm (95% CI; 0.7, 2.4 cm), and the S4 trunk passes under the ligament at 0.9 cm (95% CI; 0.3, 1.5 cm) superior to the ischial spine. The pudendal nerve forms lateral to the uterosacral ligament. Our data demonstrate that the S1-S4 trunks of the sacral plexus, not the pudendal nerve, are vulnerable to injury during uterosacral ligament suspension.

We report an unusual finding in an adult male cadaver. During the routine dissection of the posterior abdominal wall as part of an anatomy course at our institution, an anomalous muscle was noted. This muscle originated from the transverse process of the left L3 vertebrae and the medial aspect of the quadratus lumborum. We believe this muscle to represent a variety of the psoas quartus that, to our knowledge, has only been described once before in the extant medical literature. The presence of a psoas quartus muscle may contribute to femoral nerve compression. The clinician may wish to consider this rare muscular anomaly in patients with symptoms of femoral nerve compression in which no other clear etiology is found. Furthermore, clinicians who image the posterior abdominal wall should be aware of this potential anomaly when interpreting the anatomy of this region., (Copyright 2006 Wiley-Liss, Inc.)

Knowledge of segmental innervation of skeletal muscles is essential for diagnosing lumbar radiculopathy. Myotomes and dermatomes are traditionally thought to be innervated by a single spinal segment, but experimental studies have shown that this pattern of segmental innervation allows considerable overlap. This implies that muscles (or dermatomes) are innervated not only by axons of one spinal segment, but also partially by axons of adjacent spinal levels. We describe a patient in whom overlap in segmental innervation complicated adequate diagnosis of a recurrent lumbar hernia. Further, we present an outline of electrophysiological and anatomical studies on segmental innervation.

Purpose: Ultrasound technology has been applied to increase both efficacy and safety of certain peripheral nerve blocks. This case report describes the first successful ultrasound-guided lumber plexus block., Clinical Features: We describe a 91-year-old woman with aortic stenosis who successfully underwent open reduction and internal fixation of a fractured right hip with a lumbar plexus block. Ultrasound provided direct visualization to help identify the anatomical structures and guide the block needle during performance of the block. Complete block of the lumbar plexus was attained within 15 min, and the surgical procedure was performed uneventfully., Conclusion: The use of ultrasound has gained popularity to perform peripheral nerve blocks. In this case report, a successful lumbar plexus block was performed with ultrasound guidance. By direct visualization, using this technology may potentially reduce complications associated with lumbar plexus blocks.

The topographic anatomy of the lower intercostal nerves is less known than the upper ones except for the twelfth intercostal nerve. It is possible to use the lower intercostal nerves to carry out a neurotization of the lumbar roots. We studied the anatomy of the ninth, tenth, and eleventh intercostal nerves in order to specify the data of descriptive and topographic anatomy allowing to carry out their harvesting under good conditions. Ninth, tenth, and eleventh intercostal nerves of 50 cadavers were dissected. The proximal part of the nerve in the posterior intercostal space was exposed through a posterior approach. The lateral intercostal space was exposed through a lateral approach, under the latissimus dorsi, which made it possible to harvest the intercostals nerve. The proximal course of the nerve in posterior intercostals space was the same in all the cases. The nerve moves obliquely towards the outside to reach the lower border of the rib. The exit of posterior intercostal space is a fibrous strait that marks the entry of a channel between two muscular layers. We describe an aponevrotic channel in which the nerve and the vessels are, immediately at the lower border of the cranial rib. The mean total length of intercostal nerve harvested by our technique was 17.96 cm for the ninth intercostal nerve, 17.14 cm for the tenth intercostal nerve, and 15.94 cm for the eleventh intercostal nerve. The bifurcation of the intercostal nerve in a deep branch and the ramus cutaneus lateralis was found in the majority of the cases, from 9.5 to 21 cm of the emergence of the intercostal nerve in posterior intercostal space. This anatomical study of the ninth, tenth, and eleventh intercostal nerves in posterior intercostal space and lateral intercostal space appears to us to allow the realization of a reliable surgical harvesting., (Copyright 2005 Wiley-Liss, Inc.)

Non-specific low back pain and peripartum pelvic pain have aetiologies that may feature the sacroiliac region. This region possesses many potential pain-generating structures sharing common sensory innervation which makes clinical differentiation of pathoanatomy difficult. This anatomical study explores the relationship between the long posterior sacroiliac ligament (LPSL) and the lateral branches of the dorsal sacral nerve plexus. Twenty-five sides of the pelvis from 16 cadavers were studied, three for histological analysis and 22 for gross anatomical dissection. We found that the LPSL is penetrated by the lateral branches of the dorsal sacral rami of predominantly S2 (96%, 21/22) and S3 (100%, 22/22), variably of S4 (59%, 13/22) and rarely of S1 (4%, 1/22). Some of the penetrating lateral branches give off nerve fibres that disappear within the ligament. These findings provide an anatomical basis for the notion that the LPSL is a potential pain generator in the posterior sacroiliac region.

Purpose: Few studies have demonstrated the feasibility of cross innervating a skeletal muscle neosphincter with the pudendal nerve in an animal model. This study was designed to evaluate in humans the technical feasibility of anastomosing the nerve of the gracilis muscle and the pudendal nerve when the gracilis muscle is transposed around the anus., Methods: Anatomic assessment was made in 30 cases. The gracilis muscle and its principal neurovascular pedicle were dissected and the nerve to the gracilis divided at its origin. The gracilis muscle, accompanied by its nerve, was then transposed around the anus. The pudendal nerve was dissected in its extrapelvic portion and divided at its termination. Gracilis reinnervation was considered feasible when the proximal end of the nerve to the gracilis muscle and the distal end of the pudendal nerve were able to be placed into tension-free contact., Results: The mean lengths of the nerve to the gracilis and the pudendal nerve were 126.5 +/- 20.6 mm and 57.5 +/- 16.3 mm. Anastomosing the nerve of the gracilis muscle and the pudendal nerve was possible in 28 cases. There was a total mean surplus nerve length of 25.1 +/- 20.9 mm. In 26 cases, the distal end of the pudendal nerve (mean, 3.3 +/- 1.1 mm) was similar or larger than the end of the nerve to the gracilis (mean, 3 +/- 0.8 mm)., Conclusions: Anal sphincter reconstruction using transposed gracilis muscle with pudendal nerve anastomosis is anatomically achievable in cadavers, and supports the potential applications of this technique for perineal reconstruction in clinical practice.

Sensory and motor innervation of the whole lower limb is due to lumbo-sacral-plexus that arises from the spinal roots L1-S3. The whole lower limb can be blocked from its origin to the foot for surgical procedures or for postoperative analgesia. Single or continuous lumbar plexus blockade can be an alternative to general anesthesia and central block in elective and traumatic hip or femur repair, for knee surgery and for postoperative analgesia. To understand the relative plexus depth and the relationship between the plexus and the closer structure in order to avoid complicance, the aid of imaging technique such as CT-scan, MRI and ultrasounds can be considered.

The purpose of our study was to determine the location of the lateral femoral cutaneous nerve and its branches at the inguinal ligament and proximal thigh. We think that further defining the location of the nerve and its branches based on certain measurements from known anatomic landmarks would enable us to determine a danger zone that could aid in preventing iatrogenic injury to the lateral femoral cutaneous nerve. The anatomic course of the lateral femoral cutaneous nerve was studied in 29 cadaver specimens and distances from various landmarks were recorded. In addition, the branching pattern of the nerves was recorded. We observed variability in the course and branching patterns of the lateral femoral cutaneous nerve. The lateral femoral cutaneous nerve was found to potentially be at risk as far as 7.3 cm medial to the anterior superior iliac spine along the inguinal ligament and as much as 11.3 cm distal on the sartorius muscle from the anterior superior iliac spine. As many as five branches of the lateral femoral cutaneous nerve were found and in 27.6% of cases the lateral femoral cutaneous nerve branched before traversing the inguinal ligament. We used this information to describe a danger zone, which could be used as a guide to help prevent unnecessary injury during certain procedures.

We encountered a rare case of the left common iliac artery in a 92-year-old Japanese female cadaver during dissection practice for medical students. The artery entered into the small pelvis without branching to the external iliac artery. There, it went down slightly medially and then turned laterally and passed behind the first sacral nerve. The artery ran anterolaterally further and returned to the greater pelvis and became the external iliac artery, which continued to the femoral artery as usual. During the course in the small pelvis, the artery branched to give rise to each branch of the internal iliac artery. We speculate that in the present case, a communication between the median sacral artery and the superior gluteal artery, passing behind the first sacral nerve, enlarged and compensated the usual common iliac artery.

The pudendal nerve (S3-S5) is a major branch of the sacral plexus. After branching from the sacral plexus, the pudendal nerve travels through three main regions: the gluteal region, the pudendal canal, and the perineum. In the gluteal region, the pudendal nerve lies posterior to the sacrospinous ligament. The relationship of the pudendal nerve to the sacrospinous ligament has important clinical ramifications, but there is a lack of literature examining the variations in pudendal nerve anatomy in the gluteal region. This study investigates the pudendal nerve trunking in relation to the sacrospinous ligament in 37 cadavers (73 sides of pelves) of 21 males and 16 females, ranging from 18-83 years of age. Pudendal nerve trunking could be grouped into five types: Type I is defined as one-trunked (41/73; 56.2%), Type II is two-trunked (8/73; 11%), Type III is two-trunked with one trunk as an inferior rectal nerve piercing through the sacrospinous ligament (8/73; 11%), Type IV is two-trunked with one as an inferior rectal nerve not piercing through the sacrospinous ligament (7/73; 9.5%), and Type V is three-trunked (9/73; 12.3%). In summary, 56.2% of pudendal nerves adjacent to the sacrospinous ligament were one-trunked, 31.5% were two-trunked and 12.3% were three-trunked. Fifteen inferior rectal nerves originated independently from the S4 root and never joined the main pudendal nerve. Eight of fifteen inferior rectal nerves pierced through the sacrospinous ligament, perhaps making it prone for entrapment. We measured the average diameter of the main trunk of the pudendal nerve to be 4.67 +/- 1.17 mm. We also measured the average length of the pudendal nerve trunks before terminal branching to be 25.14 +/- 10.29 mm. There was no significant statistical difference in the average length, average diameter, number of trunks, and pudendal nerve variations between male and female or right or left sides of the pelves. A detailed study of pudendal nerve trunking in relationship to the sacrospinous ligament would be useful for instruction in basic anatomy courses and in relevant clinical settings as well., ((c) 2005 Wiley-Liss, Inc.)

Unlabelled: This self-directed learning module highlights mononeuropathies. It is part of the chapter on neuromuscular rehabilitation and electrodiagnosis in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on diagnostic criteria and classifications of mononeuropathies, including carpal tunnel, brachial neuritis, and lumbosacral plexopathy. The timeline status post nerve injury is discussed in relation to findings on electrodiagnostic studies. The differential diagnosis and electrodiagnostic design and interpretation is detailed in the chapter. Treatment options are reviewed., Overall Article Objective: To summarize the diagnosis, classification, and treatment of mononeuropathies, from an electrodiagnostic perspective.

Object: Reports describing surgical landmarks with which to identify the branches of the lumbar plexus found on the posterior abdominal wall are lacking in the English-language literature., Methods: The authors examined 22 sides from six female and five male cadavers. Measurements were made between the branches of the lumbar plexus and various bone landmarks such as the midline vertebral bodies, supracristal plane--a horizontal line connecting the superior-most aspect of the left and right iliac crests approximating the LA-5 vertebrae--and anterior superior iliac spine (ASIS). The mean distances from the midline and as they emerged through or lateral to the psoas major muscle to the subcostal, iliohypogastric, ilioinguinal, lateral femoral cutaneous, genitofemoral, and femoral nerves, were 5.5, 6, 6.5, 6, 4.5, and 4.5 cm, respectively. At a vertical line through the midpoint between the ASIS and the midline, the subcostal, iliohypogastric, and ilioinguinal nerves were superior to the supracristal plane at mean distances of 8, 4, and 5 cm, respectively. Inferior to the supracristal plane and in a vertical line through a midpoint between the ASIS and the midline, the lateral femoral and femoral nerves were found to have mean distances of 5 and 5.5 cm, respectively. The obturator nerve had a mean distance of 3 cm lateral to the midline. Additionally, the lateral femoral cutaneous nerve had a mean distance of 1.5 cm inferomedial to the ASIS., Conclusions: A good working knowledge of the locations and anatomy of the nerves of the lumbar plexus on the posterior abdominal wall is necessary for the surgeon who operates in this region. The measurements provided herein will aid the surgeon who wishes to expose or avoid these nerves, thus precluding injury.

Lumbar plexus is an effective but underused regional technique that was described nearly 3 decades ago. The original description has been modified several times based on advances in technology, localization, and imaging techniques. This review provides an overview of the history, anatomy, and techniques described to perform this block.

Aim: Neurogenic low urinary tract dysfunctions unresponsive to medical and conservative therapy are difficult to manage. Nowadays they can be treated with Sacral Nerve Stimulation (SNS), even if clinical experiences reported in literature are still limited., Methods: We performed SNS in 6 patients with neurogenic bladder: 3 patients had incontinence-urgency (1 myelitis, 1 multiple sclerosis, 1 autonomic polineuropathy) and 3 patients had urinary retention (1 incomplete spinal cord lesion, 1 operation for discal hernia T5-T6, 1 hysterectomy)., Results: Among cases with incontinence-urgency we achieved complete control of the bladder in 2 patients while in 1 patient the number of urinary losses was reduced of the 80%. In 2 patients with urinary retention we obtained complete recovery of the bladder function, while in 1 patient the number of cateterisms/die reduced of 50%, the urinary volume for micturion increased and residual urinary volume decreased. Results were unchanged during the follow-up (maximum 26 months), except for 1 patient in which a partial loss of effectiveness occurred., Conclusions: Chronic electric stimulation of S3 sacral roots via an implanted neuroprotesis is therefore an effectiveness, save and promising therapeutic option in treatment of neurogenic bladder dysfunctions.

Cadaveric dissection demonstrated the lumbar plexus to lie within the substance of psoas major, with the major branches of the lumbar plexus emerging into the psoas compartment adjacent to the L5 vertebra. Within psoas major, the lateral femoral cutaneous and femoral nerves were separated from the obturator nerve by a muscular fold in 36 of 60 plexuses. Anatomical variations were common, with the accessory obturator nerve being identified in 12 per cent of plexuses. All previously described lumbar plexus block approaches positioned the needle within close proximity to the lumbar plexus. Modifications to these approaches may increase efficacy and reduce complication rates.

Injury to the ilioinguinal and iliohypogastric nerves after a McBurney's incision have been reported to cause paralysis of the conjoint tendon that may lead to the development of an indirect inguinal hernia. This study reports on the incidence of ilioinguinal and iliohypogastric nerve sectioning after the performance of a classic McBurney's incision as well as the distance and relationship of the ilioinguinal and iliohypogastric nerves to the anterior superior iliac spine and a classic McBurney's incision. The right iliac fossa and lumbar region of 33 cadavers were dissected for the uncovering of the ilioinguinal and iliohypogastric nerves after a correct McBurney's incision was made. Injury to the ilioinguinal and iliohypogastric nerves was recorded. The mean distance between the ilioinguinal nerve and the incision line was 41.89 mm and 34.63 mm between the iliohypogastric nerve and the incision line. The ilioinguinal and iliohypogastric nerves were found to be 6.69 mm and 12.08 mm from the anterior superior iliac spine, respectively. No ilioinguinal or iliohypogastric nerve was injured during all 33 McBurney's incisions.

Background: This study documents the anatomy of the pudendal nerve, which has a major role in maintaining faecal continence. Unexpected faecal incontinence can develop following perineal surgery even when the anal sphincters are not damaged. In addition, injury to the pudendal nerve might be encountered during pelvic procedures such as a sacrospinous colpopexy., Methods: An anatomical study on 28 cadavers was conducted to examine the course of the pudendal nerve and its branches in the perineum., Results: In five of the 28 cadavers dissected (four male, one female), a nerve plexus was found within the ischiorectal fossa in close proximity to the anal sphincters. The plexus received contributions from interconnecting branches of the inferior rectal and perineal nerves to innervate the external anal sphincter. In 11 of the 28 cadavers (five female, six male) an additional nerve arose from the medial aspect of the pudendal nerve at the level of the sacrotuberous and sacrospinous ligaments. This nerve continued distally and gave several branches to the perineum and the levator ani muscle., Conclusion: A sound knowledge of the anatomical variations of the pudendal nerve and its branches is essential for all surgeons operating in the perineal region.

Objective: The purpose of this study was to map the course of the ilioinguinal and iliohypogastric nerves., Study Design: The courses of iliohypogastric and ilioinguinal nerves from 11 fresh frozen cadavers were mapped from their lateral emergence on the anterior abdominal wall to their midline termination in reference to fixed bony landmarks. Bivariate fit ellipses were generated for each nerve and compared with sites of standard abdominal surgical incisions., Results: Thirteen iliohypogastric and 16 ilioinguinal nerves were identified and mapped. On average, the proximal end of the ilioinguinal nerve entered the abdominal wall 3.1 cm medial and 3.7 cm inferior to the anterior superior iliac spine, then followed a linear course to terminate 2.7 cm lateral to the midline and 1.7 cm superior to pubic symphysis. The iliohypogastric nerve entered the abdominal wall on average 2.1 cm medial and 0.9 cm inferior to the anterior superior iliac spine, which followed a linear course to terminate 3.7 cm lateral to the midline and 5.2 cm superior to pubic symphysis., Conclusion: Abdominal wall surgical sites below the level of the anterior superior iliac spine have the potential for ilioinguinal or iliohypogastric injury.

Study Design: A retrospective audit and examination of anatomic findings., Objective: To examine the effectiveness of sensory stimulation-guided radiofrequency neurotomy for the treatment of recalcitrant sacroiliac joint pain., Summary of Background Data: Sacroiliac joint-mediated pain is a distinct clinical entity. The prevalence of intra-articular pain arising from the sacroiliac joint in patients with low back pain has been estimated at 15% to 30%. Unfortunately, the clinical success of current treatment methods for chronic sacroiliac pain is discouraging. Based on the anatomy of the sacral posterior primary rami and their lateral branch nerves, an anatomically based sensory stimulation-guided radiofrequency technique was developed to overcome the inherent challenge posed by the variable topography of the sacral lateral branch nerves. MATERIALS AND METHODS ANATOMIC STUDY: Meticulous dissection exposing the dorsal sacral plexus and lateral branch nerves entering the sacroiliac joint complex was performed on three cadaveric specimens. Small-gauge wires were placed adjacent to the lateral branch nerves entering the joint and over the dorsal sacrum to the dorsal sacral foramina. Fluoroscopic images were obtained correlating the location and number of these branches arising from the posterior primary rami of S1-S3 to identifiable bony landmarks., Clinical Study: A retrospective chart review was performed selecting patients who underwent sensory stimulation-guided sacral lateral branch radiofrequency neurotomy after dual analgesic sacroiliac joint deep interosseous ligament analgesic testing between February 17, 1998 and March 15, 1999., Results: A total of 14 patients met inclusion criteria for this retrospective study. Success was defined as greater than 60% consistent subjective relief and greater than a 50% consistent decrease in visual integer pain score, maintained for at least 6 months after the procedure. Sixty-four percent of patients experienced a successful outcome, with 36% experiencing complete relief. Fourteen percent of patients did not achieve any improvement. No patients experienced a complication or worsening of their pain from the procedure., Conclusions: A sensory stimulation-guided approach toward the identification and subsequent radiofrequency thermocoagulation of symptomatic sacral lateral branch nerves appears to offer significant therapeutic advantages over existing therapies for the treatment of chronic sacroiliac joint complex pain.

The surgical management of sacral tumors requires partial or total sacrectomy and spinopelvic reconstruction. These lesions present a great surgical challenge, because most spine surgeons are unfamiliar with the techniques required for these procedures. The authors describe a step-by-step operative technique and provide several illustrations. Total sacrectomy is performed by sequential anterior and posterior approaches that involve a rectus abdominis pullthrough pedicle flap reconstruction. The anterior procedure is an intraperitoneal approach used to expose the anterior aspect of the tumor, to ligate the main tumor vessels, and to conduct an anterior partial sacrectomy. After this, the rectus abdominis myocutaneous flap, based on the inferior epigastric vessel, is prepared, and a posterior sacrectomy is performed, dividing all sacral nerve roots in the thecal sac. After complete en bloc extirpation of the sacrum with tumor, spinopelvic reconstruction and closure with a myocutaneous flap are performed. Spinopelvic reconstruction is undertaken using a modified Galveston technique or double iliac screw fixation combined with posterior lumbar segmental fixation. These provide a long lever arm within the ilium to counteract the forces exerted by the lumbar spine. Understanding the nature of the disease as well as the biomechanics of the lumbosacral pelvic area and spinopelvic fixation will help surgeons select the appropriate treatment for sacral tumors.

The purpose of this study is to provide precise anatomical and statistical information about the number and location of lumbar sympathetic ganglia and the number and length of the related rami communicantes, and to consider the neurological pathway for nociception from the low back. Three-hundred ninety-three ganglia and 719 rami communicantes from 50 human cadavers were identified by gross dissection. The number of ganglia in a single lumbar chain ranged from 2 to 6, the mean being 3.9. The mean lengths of rami connected to the 1st and 5th lumbar spinal nerves, respectively, were significantly longer and shorter than those connected to the 2nd, 3rd, and 4th nerves. The lumbar sympathetic ganglia and rami communicantes were not distributed segmentally. The present results may assist in understanding the nociceptive pathway from the low back., (Copyright 2003 Wiley-Liss, Inc.)

Study Design: The distribution of the lumbar plexus was analyzed using cadavers., Objective: To clarify the safety zone to prevent nerve injuries with respect to retroperitoneal endoscopic surgery., Summary of Background Data: Surgical approaches to the retroperitoneal space vary among surgeons. Recently, retroperitoneal endoscopic surgery has been applied to various spinal disorders. When the psoas major muscle is separated during retroperitoneal endoscopic surgery, there is a potential risk of injury to the lumbar plexus or nerve roots. However, there is sparse knowledge regarding the relationship between the greater psoas muscle and the lumbar plexus., Methods: A total of 30 cadavers were analyzed. Six lumbar spines of the cadavers were cut in parallel with the lumbar disc space. Each axial section was photographed and captured into a computer. The distribution of the lumbar plexus was analyzed using computer images. The positions where the genitofemoral nerve emerged on the abdominal surface of the psoas major muscle were analyzed using 24 cadavers., Results: L2/3 and above, all parts of the lumbar plexus, and nerve roots were located from the dorsal fourth of the vertebral body and dorsally. The genitofemoral nerve descends obliquely forward through the psoas major muscle, emerging on the abdominal surface between the cranial third of the L3 vertebra and the caudal third of the L4 vertebra. The safety zone of the psoas major muscle to prevent nerve injuries, excluding the genitofemoral nerve, is at L4/L5 and above., Conclusions: The safety zone, excluding the genitofemoral nerve, is at L4-L5 and above.

Objective: To discover the anatomical basis of retroperitoneal laparoscopic surgery., Methods: Twenty Chinese adult cadavers including 12 and 8 woman were anatomized. The relationship between nerves, vessels of the lateral abdominal wall, retroperitoneal structures and the path of retroperitoneal laparoscopic surgery were measured., Results: In male cadavers, the distance between the iliac crest and lumbar trigonum was 4.02 +/- 1.26 cm on the left, and 3.83 +/- 0.90 cm an the right. The distance between the iliac crest and ilio-hypogastric nerve was 0.82 +/- 0.13 cm on the left and 0.84 +/- 0.08 cm on the right. The distance between the subcostal nerve and XII rib in the posterior axillary line and midaxilla line was 0.79 +/- 0.26 cm, 1.65 +/- 1.12 cm on the left and 0.78 +/- 0.30 cm, 1.59 +/- 1.07 cm on the right respectively. The distance between the ureter of inferior pole of kidney and extra-border of psoas was 2.24 +/- 0.67 cm on the left and 2.19 +/- 0.73 cm on the right. The distance between crossing of the ureter and iliac vessels and extra-border of psoas was 3.91 +/- 0.59 cm on the left and 3.76 +/- 0.53 cm on the right. In female cadavers, the distance between the iliac crest and trigonum lumbale was 3.90 +/- 0.37 cm on the left and 3.87 +/- 0.37 cm on the right. The distance between the iliac crest and ilio-hypogastric nerve was 0.94 +/- 0.06 cm on the left and 0.93 +/- 0.10 cm on the right. The distance between the subcostal nerve and XII rib in the posterior axillary line and midaxilla line was 0.61 +/- 0.14 cm and 1.37 +/- 0.89 cm on the left and 0.64 +/- 0.13 cm, 1.32 +/- 0.95 cm on the right respectively. The distance between the ureter of inferior pole of kidney and extra-border of psoas was 2.00 +/- 0.23 cm on the left and 1.91 +/- 0.13 cm on the right. The distance between crossing of the ureter and iliac vessels and extra-border of psoas was 3.43 +/- 0.31 cm on the left and 3.85 +/- 0.43 cm on the right., Conclusions: The top of the lumbar trigonum which is 2 cm above the iliac crest selected as the first point and 2 cm inferior to the XII rib in the posterior axillary line selected as the second point is the anatomical basis for retroperitoneal laparoscopic surgery. It can reduce the opportunity to injury nerves, vessels and retroperitoneal structures while making retroperitoneal laparoscopic surgery easy.

The origins, courses and relations of lateral femoral cutaneous nerves (LFCNs) were examined bilaterally in 28 cadavers, and the variations were observed in two. On the right side of one cadaver, the ventral rami of the first and second lumbar spinal nerves were united and then this nerve was divided into four branches. From medial to lateral, these branches were the obturator nerve, the femoral nerve, the medially located LFCN and the laterally located LFCN. On the left side of another cadaver, there were three LFCNs. All of these nerves pierced the psoas major muscle anterolaterally. Two of these nerves, which pierced the psoas major muscle more proximally than the third, united with each other by a communicating branch anterior to the iliacus muscle. These types of variations are very important, especially in the presence of paresthesias or pain in the anterior thigh, lateral thigh and gluteal region. In these cases, surgeons must always remember the possible variations of the LFCN during surgical procedures in order to prevent injury and the occurrence of meralgia paresthetica.

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., (Copyright 2002 Wiley Periodicals, Inc.)

The aim of our study was to provide quantitative data on pudendal motor neuron cell bodies and axons in the female rat. To confirm earlier studies, fluorescent retrograde tracers were used to label the motor neurons for correlation with myelinated axon counts along the length of the motor pudendal nerve. The external urethral sphincter of female rats was injected with diamidino yellow and the external anal sphincter with fast blue. The L(6) spinal cord revealed labeled motor neurons. Those in the dorsolateral column (60.8 +/- 10.6) had nuclei labeled yellow from the external urethral sphincter and those in the dorsomedial column (31.7 +/- 8.5) had cytoplasm labeled blue from the external anal sphincter. Double labeling was not present, suggesting that pudendal motor neurons in each column innervate separate sphincters. The motor pudendal nerve in the ischiorectal fossa was also characterized by light microscopy. The mean myelinated axon count (151.4 +/- 17.0) was highly correlated (r = 0.995) in the proximal fascicles and the sum of distal fascicles. This indicated that myelinated axons do not branch at the point where the main motor pudendal nerve branches into separate fascicles. Axon counts between sides were not as well correlated (r = 0.883). The ratio of motor neurons to myelinated axons is 56%, suggesting that some myelinated axons either innervate other muscles or are sensory. This reproducible characterization of the normal pudendal nerve anatomy provides an excellent basis for experimental studies associated with pudendal nerve denervation as a model for neurogenic incontinence., (Copyright 2002 Wiley-Liss, Inc.)

The sympathetic blocks are useful in many ways for relief of chronic pain. The sympathetic block can be caused at pre- and paravertebral sympathetic ganglia eg, stellate ganglia, coeliac plexus and lumbar sympathetic ganglia. Indications for sympathetic blockade are: Complex regional pain syndrome, phantom limb pain, central pain, acute pancreatitis, pancreatic cancer and cancer pain from upper abdominal viscera. Stellate ganglion blockade is required for the diagnosis, prognosis and therapy for painful and other conditions associated with sympathetic dysfunctions of head, neck and upper extremity. Coeliac plexus block is indicated in pain due to intra-abdominal cancer, stemming from organs innervated by coeliac plexus. Lumbar sympathetic block is indicated for diagnosis, prognosis and therapy for painful and other conditions associated with sympathetic dysfunctions like complex regional pain syndrome I and II, herpes zoster, amputation stump pain and inoperable peripheral vascular vasospastic diseases of the lower limb. Indications for superior hypogastric block are the prognostic and therapeutic purposes of cancer pelvic organs--uterus, cervix, bladder, prostate, urethra, testes and ovaries.

Purpose: Anesthetic infiltration of the pudendal nerve at the ischial spine can relieve perineal pain in cases of compression or distention. The aim of our study was to look for a real-time, visually controlled infiltration technique using ultrasound., Methods: Fifty-three volunteers were examined in a prone position using a 3.5-MHz curved-array probe in color-coded Doppler mode. The deep gluteal region was scanned in two perpendicular planes, longitudinal and transverse to the internal pudendal artery., Results: On the transverse planes the ischial spine, the sacrospinous ligament, and the internal pudendal artery were depicted in all but two cases. In 47.2 percent of the cases one trunk of the pudendal nerve was detected directly. Nerves consisting of more than one trunk were not found. The thickness of the nerve ranged between 3.5 and 7 mm., Conclusions: In almost one-half of the cases a direct ultrasound-guided infiltration of the pudendal nerve is possible. In the remaining cases the nerve can be detected and blocked indirectly, using the ischial spine or the internal pudendal artery as a landmark.

The authors have produced a pair of articles that can be used to rapidly identify back, hip, and lower limb muscles and their innervation(s). This article presents the motor and sensory innervation of the lower limb by color-coding structures to match their peripheral nerves. It provides a companion summary table that allows prediction of unique patterns of denervation from 12 lesions sites.

The dissection of 37 cadavers has shown that in only a third of cases, the sural nerve comes from the communication between the medial cutaneous nerve, derived from the tibial nerve, and the communicating branch of the lateral cutaneous nerve of the leg which comes from the lateral popliteal nerve. The communication is most often at the junction between the proximal two-thirds and distal third of the leg, on average 2 mm below the transverse crease of the popliteal fossa. The medial cutaneous nerve was absent in only one case. On the other hand, in 11 cases the lateral cutaneous nerve or its communicating branch was missing. In 12 cases without any anastomoses, the route of the sural nerve was followed by the medial cutaneous nerve of the leg in 9 cases and by the lateral cutaneous nerve in 3 cases. The majority of branches to the proximal half of the calf came from the lateral cutaneous nerve. In the lower part of the leg, the sural nerve and/or the medial cutaneous nerve gave numerous branches to the Achilles' tendon and to the integuments of the lateral aspect of the heel and lateral malleolus.

Background: The techniques of continuous peripheral blockades have shown to be efficient in postoperative pain control, in the various orthopaedic procedures of the limbs. The aim of this study is to evaluate the existing data about the use of a continuous blockade of the lumbar plexus or femoral nerve, together with the indications for technique and therapy., Methods: We considered the principal results of prospective, randomised studies described in literature about the assessment of a continuous peripheral blockade of the lumbar plexus or the femoral nerve in limb surgery. Furthermore we described the principal techniques for positioning the perinerval catheters in the considered sites, and the advised dosage regimen., Results: The various studies report an adequate costs/benefits relation concerning the used techniques. The analysed studies not only report an adequate efficacy of the postoperative pain control, but often show an important benefit in terms of functional recovery of the operated limbs and on final outcome of the patient., Conclusions: The use of continuous blockades of the lumbar plexus or femoral nerve shows to be an important and effective instrument not only in terms of positive effects on postoperative pain control, but also in terms of relevant advantages concerning final outcome after surgery. Nevertheless these techniques should not be considered as the only approach to postoperative pain in the orthopaedic patient, but have to be included in a global, multidisciplinary and multimodal approach.

Purpose: We report the topographic relationship of the pudendal nerve to the accompanying pudendal vessels and the ischial spine and provide the basics for an ultrasonographic depiction of these structures., Methods: Twenty-nine female and 29 male adult human cadavers were positioned prone to expose the deep gluteal region. In 58 left and 58 right pelves the course of the pudendal nerve and vessels at the ischial spine were evaluated and analyzed statistically (n = 116)., Results: Multitrunked pudendal nerves were found in 40.5 percent with a left-vs.-right ratio of 1:1.5. The diameters of the single-trunked nerves ranged from 1.3 to 6.8 (mean 3.6 +/- 1.1) mm. In 75.9 percent the pudendal nerve was found medial to the accompanying internal pudendal artery. The distance to the artery ranged from 17.2 mm medial to 8 mm lateral (mean, 3.4 mm medial +/- 4.1 mm). The distance to the tip of the ischial spine ranged from 13.4 mm medial to 7.4 mm lateral (mean, 2.1 mm medial +/- 3.7 mm)., Conclusions: The knowledge of the close spatial relationship between the pudendal nerve and the internal pudendal artery is important for any infiltration technique and even surgical release. It demands real-time, visually controlled infiltration techniques, such as with ultrasound.

This series of two articles is structured to provide anatomically accurate functional schematics of the motor and sensory innervation of the lower back, hip, and lower limb. This first paper provides radiographically oriented schematic axial sections of the lower back and hip in which the muscles are appropriately color-coded to match the peripheral nerves. A companion color-coded summary table allows prediction of unique patterns of denervation from 25 lesion sites. These are divided into three categories (roots T12 to S4, four plexal quadrants, and 11 sectional levels). Correlation between an imaging abnormality at one of these lesion sites and the predicted denervation pattern ensures the lesion is, in fact, clinically significant. The next article will continue this color-coded approach into the lower limb.

The manner of innervation of the obturator internus, superior and inferior gemelli, and the quadratus femoris in humans (101 pelvic halves) and in rhesus monkeys (Macaca mulatta: 8 pelvic halves) were investigated. In most specimens, the inferior gemellus originated from the lateral surface of the ischial tuberosity and also from the medial surface (intrapelvic origin) just beneath the obturator internus and was covered by the falciform process of the sacrotuberous ligament. The superior gemellus was frequently innervated by the nerve to the obturator internus and the nerve to the quadratus femoris (60.4%), and the inferior gemellus was innervated by the obturator internus nerve in two specimens. The quadratus femoris nerve originated from more cranial segments than the obturator internus nerve, however these nerves had various communication patterns inside and outside the muscles. According to the intramuscular nerve distribution, in some specimens the branches to the superior gemellus from the quadratus femoris nerve extended to the inferior gemellus, and the branches to the inferior gemellus were distributed to the obturator internus. The present findings revealed that the positional relationships among the branches to the obturator internus and gemelli muscles are relatively constant, although the branching patterns and innervation patterns were varied. The various patterns and routes are considered to reflect the variability of the differentiation patterns of the anlage of the muscles. A possible schematic model of the positional relationships between the muscles and the nerves is proposed.

Purpose: Functional neosphincters after pudendal nerve anastomosis proved possible in animal models and may be applicable in humans, but access is a recognized problem. We report the occurrence of pudendal nerve anomalies, its implications for reconstruction, and describe a new approach for maximal exposure., Methods: Adult human cadavers were positioned prone and dissected via a gluteal approach. Pudendal nerve variations and physical measurements were analyzed statistically., Results: A new, simple, four-step approach (surface landmarks and exposure of gluteus maximus muscle, sacrotuberous ligament, and pudendal neurovascular bundle) permitted optimal pudendal nerve exposure in all 14 human cadavers (28 limbs). Six were males and had a mean age of 82 (range, 58-102) years. Two anomalies, Type 1 (2-trunked) and Type 2 (3-trunked), of the pudendal nerve were recognized in 30 percent of cadavers, with a left-to-right ratio of 2.5:1. Mean pudendal nerve length over the ischial spine was 23.9 (range, 19-28) mm right, 24.2 (range, 19-28) mm left (P = 0.54), but its diameter measured 5.2 mm (right) and 4.9 mm (left; P = 0.04). Mean length of pudendal nerve trunk exposed after reflection of the sacrotuberous ligament was 55 (range, 44-75) mm on either side before division into terminal branches. The number and percent frequency of inferior rectal nerve on both sides were 1 (13 percent), 2 (76 percent), and 3 (11 percent), respectively, with a mean length of 27.1 (range, 21-34) mm right and 27.9 (range, 20-33) mm left (P = 0.31)., Conclusion: A simple four-step approach to the pudendal nerve contributes to improved access in all cases. It facilitates reconstruction because it allows accurate nerve selection and recognition of potential anomalies that might influence functional outcome.

Spinal motoneurons innervating skeletal muscles comprised predominantly of high oxidative fibers, i.e. slow oxidative and fast oxidative glycolytic, have higher oxidative enzyme activities than motoneurons innervating skeletal muscles comprised primarily of low oxidative fibers, i.e. fast glycolytic. These findings suggest that there is a close relationship between the oxidative phosphorylation capacity of a motoneuron and of the muscle fibers that it innervates. Since some skeletal muscles become faster and less oxidative after 4-14 days of spaceflight, it might be expected that oxidative enzyme activities in some motoneurons also may decrease after spaceflight. In addition, there is significant muscular atrophy after even short spaceflights and, therefore, it may be expected that some motoneurons associated with these muscles also would atrophy. In the present paper, we examine the issue of whether spaceflight induces changes in the oxidative enzyme activity and/or size of spinal motoneurons.

There are no detailed descriptions of the neural structures that may be seen during surgical interventions of the pelvis. Anatomic dissections were performed to see which nerves are endangered in approaches to the anterior sacroiliac joint for plate fixations. Sixty cadavers were dissected bilaterally. Fifty-one were male and nine were female. L4 and L5 nerve roots were followed along the sacroiliac joint from the intervertebral foramen to the entrance into the lesser pelvis. Measurements were made between the nerves and sacroiliac joint from the proximal end of the joint to the pelvic brim. The L4 nerve root and the lumbosacral trunk (and not the L5 nerve root) were the nerves most susceptible to injury because of their course and proximity to the sacroiliac joint. As a result, during the anterior approach and fixation of the sacroiliac joint with plates, extreme care should be taken to identify the L4 nerve root or lumbosacral trunk or both at the anteroinferior third of the joint because the distance between the nerve and the joint is less than 1 cm.

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

The psoas compartment acts as a conduit for the nerve roots of the lumbar plexus. Originating at approximately the 12th thoracic vertebrae, this potential compartment continues on caudally, bordered posterolaterally by fascia of the quadratus lumborum and iliacus muscles, medially by the fascia of the psoas major muscle, and anteriorly by the transversalis fascia. This natural "gutter" acts as a repository for local anesthetic agents and provides an excellent method of unilateral anterior lower extremity anesthesia. After elicitation of a motor evoked response in the muscles of the anterior thigh, 30 to 40 milliliters of local anesthetic is incrementally injected into the compartment. Spread of the anesthetic to all roots of the plexus occurs in 15 to 20 minutes. Profound sensory and motor blockade can be achieved providing surgical anesthesia as well as long duration postoperative pain relief.

Seven adult cadaver lumbopelvises were harvested to study the anatomic relationship of the L4 and L5 nerves to S1 dorsal screw placement and the location of the L4, L5, and S1 nerves on plain radiographs. The mean lateral angle of S1 screw trajectory toward the L4 nerve was 31+/-8 degrees, and the mean screw trajectory length was 53+/-8 mm. The mean lateral angle of the screw trajectory toward the L5 nerve was 21+/-8 degrees, and the mean screw trajectory length was 38+/-4 mm. On both inlet and outlet radiographs, the lateral angle of the nerves increased from L4 to S1. The L4 nerve coursed over the middle third of the superior ala in the inlet view and the middle third of the lateral mass in the outlet view. The L5 nerve coursed over the inner third of the superior ala and inner third of the lateral mass. On the lateral view, the mean distances from the sacral promontory to the L4, L5, and S1 nerves along the anterior border of the sacrum were 4+/-7 mm, 12+/-5 mm, and 28+/-8 mm, respectively. This study suggests that S1 sacral screws be directed between 30 degrees and 40 degrees lateral to avoid compromising the lumbosacral trunk and sacroiliac joint.

The rhabdosphincter of the male urethra and its innervation are still a subject of controversy. Essentially, two concepts of its anatomy can be found in the literature. Some authors describe the rhabdosphincter as part of the urogenital diaphragm caudal to the prostate, others as a striated muscle that extends from the base of the bladder to the "urogenital diaphragm." In anatomic histological studies, the rhabdosphincter and its innervation were examined by means of anatomical dissections and serial anatomical as well as histological sections of 19 male pelves, including 8 fetal specimens. The rhabdosphincter presents as a vertical structure extending from the bulb of the penis to the region of the bladder neck along the prostate and the membranous urethra. Inserting dorsally in the perineal body via a broad tendinous raphe, the striated muscle fibers form an omega-shaped loop around the anterior and lateral aspects of the membranous urethra. The existence of a "urogenital diaphragm" and a strong, circular, striated "external sphincter urethrae" completely encircling the urethra caudal to the apex of the prostate cannot be confirmed by anatomical and histological investigations. The rhabdosphincter is supplied by branches of the pudendal nerve after leaving the pudendal canal.

The technique of continence-preserving anatomic radical retropubic prostatectomy focuses on the preservation of the following anatomic components of the external striated urethral sphincteric complex: (1) the entire circumference of the rhabdosphincter musculature, (2) the periurethral fascial investments (the pubourethral ligaments anterolaterally and median fibrous raphe posteriorly), and (3) the innervation of both the rhabdosphincter by way of the intrapelvic branch of the pudendal nerve (somatic) and the mucosal and smooth muscle components by way of the urethral branch of the inferior hypogastric plexus (autonomic). The clinical impact of preserving the external striated urethral sphincter and its innervation by performing a continence preserving anatomic retropubic prostatectomy is a shorter time to achieve urinary continence.