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

BACKGROUND: Together with an increased interest in minimally invasive lateral transpsoas approach to the lumbar spine goes a demand for detailed anatomical descriptions of the lumbar plexus. Although definitions of safe zones and essential descriptions of topographical anatomy have been presented in several studies, the existing literature expects standard appearance of the neural structures. Therefore, the aim of this study was to investigate the variability of the extrapsoas portion of the lumbar plexus in regard to the lateral transpsoas approach. METHODS: A total of 260 lumbar regions from embalmed cadavers were utilized in this study. The specimens were dissected as per protocol and all nerves from the lumbar plexus were morphologically evaluated. RESULTS: The most common variation of the iliohypogastric and ilioinguinal nerves was fusion of these two nerves (9.6%). Nearly in the half of the cases (48.1%) the genitofemoral nerve left the psoas major muscle already divided into the femoral and genital branches. The lateral femoral cutaneous nerve was the least variable one as it resembled its normal morphology in 95.0% of cases. Regarding the variant origins of the femoral nerve, there was a low formation outside the psoas major muscle in 3.8% of cases. The obturator nerve was not variable at its emergence point but frequently branched (40.4%) before entering the obturator canal. In addition to the proper femoral and obturator nerves, accessory nerves were present in 12.3% and 9.2% of cases, respectively. CONCLUSION: Nerves of the lumbar plexus frequently show atypical anatomy outside the psoas major muscle. The presented study provides a compendious information source of the possibly encountered neural variations during retroperitoneal access to different segments of the lumbar spine.

Anatomical study of the relationship between the lumbar intervertebral disc, nerves, and psoas major.

Cadaveric study; To describe the characteristics of the nerve and its relationship with the lumbar intervertebral disc and psoas major muscle. Nerve injury is an understudied complication of extreme lateral interbody fusion. A detailed description of the nerve anatomy would be helpful for surgeons to minimize the risk of this complication. The lumbar plexus and lumbar sympathetic nerve of 10 embalmed male cadavers were dissected, and the distribution, number, and spatial orientation of the nerves on the L1/2 to L4/5 intervertebral discs were examined. Metal wires were applied along nerve paths through the psoas major muscle. The position of the nerves was examined on CT. In zone III at L1/2 and L4/5, no nerves were found. In zone II and zone III at L2/3, no lumbar plexus was found, and only the ramus communicans passed through. At the L1-L5 level, the density of nerves in the posterior half of the psoas major muscle was greater than that in the anterior half. The lumbar plexus was found in all of zone IV. The genitofemoral nerve emerges superficially and anteriorly from the medial border of the psoas major at the L3-4 level, but at the L1/2 level, the sympathetic trunk is located in zone II. The remaining disc-level sympathetic trunks appear in zone I. No nerves were found in zone III of the L1/2 or L4/5 disc. In zones II and III of L2/3, the lumbar plexus appears safe. The genitofemoral nerve travels through zones II and III of L3/4. The distribution density of nerves in the posterior half of the psoas major muscle was greater than that in the anterior half of that muscle at the L1-L5 level.

A comparison of the motor effects and analgesic efficacy following lumbar plexus block combined with sciatic nerve block or epidural in dogs undergoing tibial plateau leveling osteotomy.

OBJECTIVE: To compare motor effects and analgesic efficacy following an ultrasound-guided lateral approach to lumbar plexus blockade at L7 and sciatic nerve blockade (LPSNB) against epidural injection in dogs undergoing tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Prospective, randomized, blinded clinical trial. ANIMALS: A total of 27 healthy adult dogs undergoing unilateral TPLO surgery. METHODS: Dogs were allocated to either LPSNB (bupivacaine 2 mg kg-1, 0.75%) or epidural (morphine PF 0.1 mg kg-1 and bupivacaine 0.5 mg kg-1, 0.75%). Other aspects of clinical management were identical, including anesthetic drug protocol, area of presurgical clipping and bladder care. Time to perform the block, response to surgical stimuli, pain scores, rescue analgesia, time to stand and walk, motor score and time to first urination were recorded. One evaluator, unaware of treatment status, performed all evaluations. Student's t-test or Mann-Whitney U test was used to compare continuous variables between groups, and Fisher's exact test for categorical variables. RESULTS: Median (range) times to stand and walk were shorter for LPSNB [60 (40-120) minutes and 90 (60-150) minutes, respectively, p = 0.003] than for epidural [150 (120-240) minutes and 180 (120-360) minutes, respectively, p = 0.006]. Four dogs required rescue intraoperatively (three in epidural group, one in LPSNB group, p = 0.438). Pain scores over the 24 hour evaluation period were similar, and not significantly different, for each group. Time to spontaneous urination [LPSNB, 330 (240-360) minutes; epidural, 300 (120-1440) minutes, p = 1.0] did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: An ultrasound-guided lateral paravertebral approach to the lumbar plexus within the psoas compartment at L7, combined with sciatic nerve blockade, allows faster return to normal motor function, with similar pain control and impact on urination when compared with epidural in dogs after TPLO surgery.

An Approach to the Examination of the Lumbar Plexus for Neurosurgical Residents: A Video Manuscript.

The lumbar plexus provides innervation to the lower limbs and is essential in enabling motor movement and sensation in the lower limbs. Some of its branches also innervate the muscles in the pelvic girdle. Compared to the brachial plexus in the upper limbs, the lumbar plexus appears to garner less recognition among physicians and surgeons. However, it is important to understand the anatomy of the lumbar plexus and its branches along with the innervation they enable, as injury to them can cause plexopathies and pathologies that should be recognised by any treating clinician. Lumbar disc herniation, trauma and entrapment by muscles or hypertrophic ligaments are common causes of lumbar plexus or nerve injuries. A video was produced to demonstrate the examination techniques explained in this article. To provide comprehensive examination of the lower limbs, the sciatic nerve and its branches are also included in the examination video.

Dissimilar Planes and Approaches with Common Neural Targets - A Cadaveric Evaluation of Three Different Ultrasound-guided Fascial Plane Blocks for Lumbar Plexus Nerves.

Background: The lumbar plexus (LP) is a group of nerves located at the fourth lumbar vertebra level, between the anterior two-thirds and posterior one-thirds of the psoas muscle. In this study, the researchers aimed to investigate the spread of latex in injections of LP, suprainguinal fascia iliaca, and circum-psoas planes to assess the different regional techniques for blocking LP nerves (LPNs). Methods: The study involved performing ultrasound-guided injections of three different colored latexes in six cadavers. The researchers observed and compared the spread of latex in each plane by taking cross sections at the levels of L4, anterior superior iliac spine (ASIS), and sacral foramina (SF). The spread of latex and LPN staining was documented and analyzed through photography. Results: The results showed that the latex spread within the psoas muscle and fascia iliaca plane (FIP) during LP injections, whereas suprainguinal fascia iliaca injections showed latex dissemination in the FIP at both ASIS and SF levels. On the other hand, circum-psoas injections spread beneath the iliopsoas fascia at both levels and medially toward the external iliac vessels. Despite this spread, there was no communication between the three planes, and there was no mixing of latex from the different injections at any level. Conclusion: There are distinct fascial planes, for the three approaches, with no communication between them. While latex diffused from LP plane to FIP, no mixing of dye was observed and also the reverse could not be achieved. These findings suggest that different regional techniques for blocking LPNs have their unique planes of action.

Incidence and risk factors of lumbar plexus injury in patients undergoing oblique lumbar interbody fusion surgery.

PURPOSE: To investigate the incidence and risk factors of lumbar plexus injury (LPI) after oblique lumbar interbody fusion (OLIF) surgery. METHODS: A total of 110 patients who underwent OLIF surgery between January 2017 and January 2021 were retrospectively reviewed. Patients were divided into two groups: the group with LPI (LPI group) and the group without LPI (non-LPI group). The baseline demographic data, surgical variables and radiographic parameters were compared and analyzed between these two groups. RESULTS: Among all participants, 13 (8.5%) had LPI-related symptoms postoperatively (short-term), and 6 (5.5%) did not fully recover after one year (long-term). Statistically, there were no significant differences in the baseline demographic data, surgery duration, intraoperative blood loss, preoperative diagnosis, surgical procedures used and incision length. Compared with the non-LPI group, patients in the LPI group had a narrower OLIF channel space. In LPI group, the anterior edge of left psoas major muscle overpasses the anterior edge of surgical intervertebral disk (IVD) on axial MRI. Logistic regression analysis revealed that narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD on axial MRI were independently associated with both short-term and long-term LPI. CONCLUSION: Narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD are significant risk factors of OLIF surgery-related LPI. Surgeons should use preoperative imaging to adequately assess these risk factors to reduce the occurrence of LPI.

Position of lumbar plexus nerves in the psoas major: Application to transpsoas approaches to the lumbar spine.

Far lateral interbody fusion is a minimally invasive operating technique. However, the incidence of postoperative neurological complications is high, and some scholars question its safety. This study describes the neuroanatomical features and spatial orientation within the psoas major. Ten embalmed male cadavers were selected and the left psoas major was dissected. Subsequently, the area between the anterior and the posterior edges of the vertebral body was divided into three equal zones. The nerves' distribution, number, and spatial orientation of the L1/2 to L4/5 intervertebral discs were examined. A caliper was used to measure the diameter of the nerve. The safety zone of the L1/2 intervertebral disc level is located in zone I and II, the relative safe zones of the L2/3 and L4/5 intervertebral discs are located in zone II, and the safety zone of the L3/4 intervertebral disc level is located in the caudal side of zone II. The genitofemoral nerve exits the psoas major in a co-trunk or two-branch pattern, and its exit point was distributed between the L3 and L4 vertebral bodies, mainly at the L3/4 intervertebral disc level. The sympathetic ganglia in the psoas major appeared only in zone I at the L2/3 intervertebral disc level. This is a systematic anatomical study that describes the nerves of the psoas major. Spine surgeons can use this study-which consists of important clinical implications-for preoperative planning, and thus, reduce the risk of nerve injury during surgery.

Prominent caudal shift of the lumbar plexus roots in spines with 18 thoracolumbar vertebrae.

PURPOSE: It remains unclear whether concomitant changes in the thoracolumbar (TL) vertebrae and lumbar plexus roots seen in experimental embryology are present in humans with different vertebral formulas, particularly in humans with 18 TL vertebrae. We thus investigated the human lumbar plexus root changes occurring in spines with an additional TL vertebra (18TL). METHODS: The lumbosacral plexus was macroscopically dissected in TL anomaly cases found in 161 computed tomography examinations. TL anomalies were distinguished as simple abnormalities in total TL count and abnormal TL trade-offs, i.e., exchanges between the last thoracic and first lumbar vertebrae, and were analyzed separately. RESULTS: One additional TL vertebra (7C_18TL_5S) was observed in 4/159 cases (2.5%), excluding cases with cervical and sacral abnormalities. Different from the unclear shifts of nerve roots in cases with 16TL and 17TL trade-offs, the 18TL trade-off tended to involve a caudal shift at the cranial limit, without event change at the caudal limit. In addition, only one nerve segment shift was reconfirmed with a change in two vertebral segments from 16 to 18 TL vertebrae. CONCLUSIONS: We revealed that concomitant changes in the lumbar plexus roots and vertebrae in humans with 18TL vertebrae may become more pronounced than those in humans with 16 or 17TL vertebrae, by approaching the typical mammalian TL formula (19TL). This study showed that the TL formula can be used to estimate changes in the lumbar plexus roots, which may assist in the planning of nerve-sparing spinal and pelvic surgery.

[Choosing the right imaging for the diagnostics and assessment of the course of peripheral nerve injuries]. / Die Wahl der richtigen Bildgebung zur Diagnostik und Verlaufsbeurteilung peripherer Nervenverletzungen.

BACKGROUND: Nerve injuries are a frequent problem in routine clinical practice and require intensive interdisciplinary care. OBJECTIVE: The current status of imaging to confirm the diagnosis of nerve injuries is described. The role of high-resolution ultrasound and magnetic resonance imaging (MRI) in the diagnostics and follow-up of peripheral nerve injuries is elaborated. MATERIAL AND METHODS: Review of the current state of imaging to confirm the diagnosis of nerve injuries. RESULTS: Depending on the suspected site of damage, the primary domain of magnetic resonance (MR) imaging (MR neurography) is injuries in the region of the spine, nerve roots, brachial plexus and lumbar plexus, pelvis and proximal thigh. In contrast, in other peripheral nerve lesions of the extremities the advantages of high-resolution nerve ultrasound in a dynamic setting predominate. The MR neurography is indicated here, especially in the frequent bottleneck syndromes and only in very isolated and selected cases. CONCLUSION: In addition to a correct anatomical assignment, the timely decision for a possible intervention and the appropriate concomitant treatment are an important basis for a favorable prognosis of nerve injuries. Imaging techniques should therefore be used early in the diagnostics and follow-up controls of peripheral nerve injuries.

Elimination of Lumbar Plexus Injury by Changing the Entry Point and Traction Direction of the Psoas Major Muscle in Transpsoas Lateral Lumbar Spine Surgery.

Background and Objectives: The lateral approach is commonly used for anterior column reconstruction, indirect decompression, and fusion in patients with lumbar degenerative diseases and spinal deformities. However, intraoperative lumbar plexus injury may occur. This is a retrospective comparative study to investigate and compare neurological complications between the conventional lateral approach and a modified lateral approach at L4/5. Materials and Methods: Patients with a lumbar degenerative disease requiring single-level intervertebral fusion at L4/5 were included and categorized into group X and group A. Patients in group X underwent conventional extreme lateral interbody fusion, while those in group A underwent a modified surgical procedure that included splitting of the anterior third of the psoas muscle, which was dilated by the retractor on the anterior third of the intervertebral disc. The incidence of lumbar plexus injury, defined as a decrease of ≥1 grade on manual muscle testing of hip flexors and knee extensors and sensory impairment of the thigh for ≥3 weeks, on the approach side, was investigated. Results: Each group comprised 50 patients. No significant between-group differences in age, sex, body mass index, and approach side were observed. There was a significant between-group difference in intraoperative neuromonitoring stimulation value (13.1 ± 5.4 mA in group X vs. 18.5 ± 2.3 mA in group A, p < 0.001). The incidence of neurological complications was significantly higher in group X than in group A (10.0% vs. 0.0%, respectively, p < 0.05). Conclusions: In our modified procedure, the anterior third of the psoas muscle was entered and split, and the intervertebral disc could be reached without damaging the lumbar plexus. When performing lumbar surgery using the lateral approach, lumbar plexus injury can be avoided by following surgical indication criteria based on the location of the lumbar plexus with respect to the psoas muscle and changing the transpsoas approach to the intervertebral disc.

Effects of thigh extension on the position of the femoral nerve: application to prone lateral transpsoas approaches to the lumbar spine.

Some authors have suggested that thigh extension during the prone lateral transpsoas approach to the lumbar spine provides the theoretical advantage of providing posterior shift of the psoas muscle and plexus and is responsible for its lower rates of nerve injury. We aimed to elucidate the effects of surgical positioning on the femoral nerve within the psoas muscle via a cadaveric study. In the supine position, 10 fresh frozen adult cadavers had a metal wire secured to the pelvic segment of the femoral nerve and then extended proximally along with its L2 contribution. Fluoroscopy was then used to identify the wires on the femoral nerves in a neutral position and with the thigh extended and flexed by 25 and 45°. Additionally, a lateral incision was made in the anterolateral abdominal wall to mimic a lateral transpsoas approach to the lumbar spine, and measurements were made of the amount of movement in the vertical plane of the femoral nerve from neutral to then 25 and 45° of thigh flexion and extension. On fluoroscopy, the femoral nerves moved posteriorly at a mean of 10.1 mm with thigh extension. Femoral nerve movement could not be detected at any degree of this range of flexion of the thigh. Extension of the thigh to about 30° can move the femoral nerve farther away from the dissection plane by approximately one centimeter. This hip extension not only places the femoral nerve in a more advantageous position for lateral lumbar interbody fusion procedures but also helps to promote accentuation of lumbar lordosis.

Saphenous somatosensory-evoked potentials monitoring of femoral nerve health during prone transpsoas lateral lumbar interbody fusion.

PURPOSE: To assess whether saphenous somatosensory-evoked potentials (saphSSEP) monitoring may provide predictive information of femoral nerve health during prone lateral interbody fusion (LIF) procedures. METHODS: Intraoperative details were captured prospectively in consecutive prone LIF surgeries at a single institution. Triggered electromyography was used during the approach; saphSSEP was monitored throughout using a novel system that enables acquisition of difficult signals and real-time actionable feedback facilitating intraoperative intervention. Postoperative neural function was correlated with intraoperative findings. RESULTS: Fifty-nine patients (58% female, mean age 64, mean BMI 32) underwent LIF at 95 total levels, inclusive of L4-5 in 76%, fixated via percutaneous pedicle screws (81%) or lateral plate, with direct decompression in 39%. Total operative time averaged 149 min. Psoas retraction time averaged 16 min/level. Baseline SSEPs were unreliable in 3 due to comorbidities in 2 and anesthesia in 1; one of those resulted in transient quadriceps weakness, fully recovered at 6 weeks. In 25/56, no saphSSEP changes occurred, and none had postoperative femoral nerve deficits. In 24/31 with saphSSEP changes, responses recovered intraoperatively following intervention, with normal postoperative function in all but one with delayed quadriceps weakness, improved at 4 months and recovered at 9 months, and a second with transient isolated anterior thigh numbness. In the remaining 7/31, saphSSEP changes persisted to close, and resulted in 2 transient isolated anterior thigh numbness and 2 combined sensory and motor femoral nerve deficits, both resolved at between 4 and 8 months. CONCLUSIONS: SaphSSEP was reliably monitored in most cases and provided actionable feedback that was highly predictive of neurological events during LIF. LEVEL OF EVIDENCE: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis.

PURPOSE: Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed. METHODS: This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test. RESULTS: Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5. CONCLUSIONS: This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

The Efficacy and Safety of Regional Nerve Blocks in Total Hip Arthroplasty: Systematic Review and Direct Meta-Analysis.

BACKGROUND: Regional nerve blocks may be used as a component of a multimodal analgesic protocol to manage postoperative pain after primary total hip arthroplasty (THA). The purpose of our study was to evaluate the efficacy and safety of regional nerve blocks after THA in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management. METHODS: We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for studies published prior to March 24, 2020 on fascia iliaca, lumbar plexus, and quadratus lumborum blocks in primary THA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of the regional nerve blocks. RESULTS: An initial critical appraisal of 3,382 publications yielded 11 publications representing the best available evidence for an analysis. Fascia iliaca, lumbar plexus, and quadratus lumborum blocks demonstrate the ability to reduce postoperative pain and opioid consumption. Among the available comparisons, no difference was noted between a regional nerve block or local periarticular anesthetic infiltration regarding postoperative pain and opioid consumption. CONCLUSION: Local periarticular anesthetic infiltration should be considered prior to a regional nerve block due to concerns over the safety and cost of regional nerve blocks. If a regional nerve block is used in primary THA, a fascia iliaca block is preferred over other blocks due to the differences in technical demands and risks associated with the alternative regional nerve blocks.

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

BACKGROUND: Laparoscopic triple neurectomy is an available treatment option for chronic groin pain, but a poor working knowledge of the retroperitoneal neuroanatomy makes it an unsafe technique. OBJECT: Describe the retroperitoneal course of iliohypogastric, ilioinguinal, lateral femoral cutaneous and genitofemoral nerves, to guide the surgeon who operates in this region. METHODS: Fifty adult cadavers were dissected resulting in 100 anatomic specimens. Additionally, 30 patients were operated for refractory chronic inguinal pain, using laparoscopic triple neurectomy. All operations and dissections were photographed. Measurements were made between the nerves of the lumbar plexus and various landmarks: interneural distances in a vertical midline plane, posterior or anterior iliac spine and branch presentation model. RESULTS: The ilioinguinal and iliohypogastric nerves were independent in 78% (Type II) and separated by an average of 2.5 ± 0.8 cm. In surgery study, only 38% were recognized as Type II and at a significantly greater distance (3.5 ± 1.2 cm, p < 0.001). The distance between ilioinguinal and lateral femoral cutaneous nerves was also greater during surgery, with statistical significance (5.1 ± 1.5 versus 4.2 ± 1.5, p < 0.005). The distance of the nerves to their bone references were not statistically different. The genitofemoral nerve emerged from the psoas major muscle in 20% as two separate branches (Type II), regardless of the study. The lateral femoral cutaneous nerve had a mean distance of 0.98 ± 1.6 cm medial to the anterior superior iliac spine. CONCLUSION: The identification of the IH, II, FC and GF nerves is essential to reduce the rate of failures in the treatment of CGP. The frequent anatomical variations of the lumbar plexus nerves make knowledge of their courses in the retroperitoneal space essential to ensure safe surgery. The location of the nerves in the LTN is distorted by up to 1 cm. regarding references in the cadavers.

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

BACKGROUND: Fascia iliaca compartment block (FICB) is an anterior approach to the lumbar plexus block and provides the effective adjunctive analgesia for total hip arthroplasty (THA). METHODS: As a case series study, 28 patients (≥ 65 years old) with THA were received a modified in-plane ultrasound-guided supra-inguinal (S-FICB) as an analgesic adjunct to evaluate the analgesic effectiveness and the local anesthetic diffusion with magnetic resonance imaging (MRI). A combination of propofol and sufentanil was administered to conduct target-controlled infusion. RESULTS: The pain scores were 1 (0-4), 2 (1-5), 3 (1-6) and 3 (1-6) at 4, 8, 12, and 24 h. The cumulative opioids were 8 (8-12), 18 (16-32), 28 (24-54) and 66 (48-104) mg of i.v. morphine equivalents at 4, 8, 12, and 24 h. The patient-controlled analgesia (PCA) times were 0 (0-1), 1 (0-2), 2 (0-5) and 5 (3-8) at 4, 8, 12, and 24 h. In lateral, anterior and medial part of thigh, the sensory blockade in 28 patients was 23 (82 %), 21 (75 %) and 19 (68 %) at 5 min; 28 (100 %) at 10 and 20 min. Motor blockade of femoral nerve (FN) and obturator nerve (ON) was present in 13 (46 %) and 3 (11 %) patients at 5 min, 24 (86 %) and 9 (32 %) at 10 min, 26 (93 %) and 11 (39 %) at 20 min. Injectate permeated to the FN and extended superiorly over the surface of iliac muscle (IM) and pectineus muscle (PM) in all patients. CONCLUSIONS: The modified S-FICB has provided an effective postoperative analgesic adjunct after THA with the satisfactory blockade of femoral (FN), obturator (ON) and sciatic (SN) nerves, especially for ON, when compared with the existing techniques.

Contralateral obturator nerve transfer for femoral nerve restoration: a case report.

BACKGROUND: Femoral nerve injury may occur in severe traffic accident injuries with pelvic fracture. Sural nerve grafts or ipsilateral obturator nerve transfer may be used to restore femoral nerve function. We report a new procedure transferring the contralateral obturator nerve to restore femoral nerve function. CASE DESCRIPTION: A 30 year-old male suffering complete lumbar plexus rapture received a contralateral obturator nerve transfer in our hospital. At 2 years follow up he had gained Medical Research Council Grade 3 muscle strength in his 23th months follow-up, with normal gait, Lower Extremity Functional Scale score of 58.75% and Femoral Nerve Motor Function Scale score 61%. CONCLUSION: The contralateral obturator nerve transfer is a reliable alternative if the nerve graft or ipsilateral obturator nerve cannot be performed.

Postfixed lumbosacral plexus with split L5 ventral ramus and furcal nerve arising from L5.

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.

Rare variation of the furcal nerve.

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.

Flow dynamics of ultrasound-guided lumbar plexus block in adults.

Background and Aims: The outcomes of plexus and peripheral nerve blocks depend on needle-nerve contact and the spread of local anesthetic (LA) around the plexus or nerve. Needle-nerve distance and spread of LA could be visualized during US-guided lumbar plexus block (LPB). Material and Methods: After Institutional Ethics Committee approval and after obtaining informed consent, 24 American Society of Anesthesiologists'-physical status I-III patients who underwent surgical fixation of fractures of proximal femur were enrolled. Spinal anesthesia was a primary anesthetic in all patients. At the end of the surgery, all patients received US and neurostimulation-aided LPB at the third lumbar nerve root (LNr). The primary aim was to determine the spread of LA in the lumbar plexus area with the relation of the needle tip and LNr contact. The secondary aim was to understand block efficacy in terms of pain scores monitored at regular intervals and 100 mg intravenous tramadol was administered as a rescue analgesic if VAS >4. Results: In all 24 patients, we observed an oval and antegrade LA spread after lumbar plexus was identified with neurostimulation at L3. With the needle closer to intervertebral foramina (IVF), a retrograde spread was visualized. Only 2/24 patients received rescue analgesia in the first 24 h. Conclusion: The type of spread after the US-guided LPB could predict block success of block and a possible epidural spread.