Brachial Plexus Examination and Localization Using Ultrasound and Electrical Stimulation: A Volunteer Study

Background: Current techniques of brachial plexus block are "blind," and nerve localization can be frustrating and time consuming. Previous studies on ultrasound-assisted brachial plexus blocks are mostly performed with scanning probes of 10 MHz or less. The authors tested the usefulness of a state-of-the-art, high-resolution ultrasound probe (up to 12 MHz) in identifying the brachial plexus in five locations of the upper extremity and in guiding needle advancement to target before nerve stimulation.

Methods: In this prospective observational study, 15 volunteers underwent brachial plexus examination using an L12-L5 MHz probe and a Philips-ATL 5000 ultrasound unit in the interscalene, supraclavicular, infraclavicular, axillary, and midhumeral regions. Thereafter, an insulated block needle was advanced under direct ultrasound guidance to target nerves before confirmation by electrical nerve stimulation in five volunteers in each of the interscalene, supraclavicular, and axillary regions. The quality of brachial plexus images, anatomic variations, and the technique of needle advancement for nerve localization were recorded.

Results: The brachial plexus components were successfully identified in the transverse view as round to oval hypoechoic structures with small internal punctuate echos in all regions examined except the infraclavicular area (visualized in 27% of the cases). The authors' technique of advancing the needle in-line with the ultrasound beam allowed moment-by-moment observation of the needle shaft and tip movement at the time of nerve localization. Hypoechoic structures were stimulated electrically and confirmed to be nerves.     

Sciatic Neuropathy: Case Report and Discussion of the Literature on Postoperative Sciatic Neuropathy and Sciatic Nerve Tumors

Sciatic nerve injury and dysfunction is not an uncommon cause of lower extremity symptoms in a musculoskeletal practice. We present the case of a man who presented with lower extremity weakness, pain, and cramps, and was initially diagnosed at an outside institution with bilateral S1 radiculopathies and recommended for spine surgery. He came to us for a second opinion. Electrodiagnostic testing revealed an isolated sciatic neuropathy and the patient was referred for imaging, which showed a sciatic nerve sheath tumor. Review of the literature on sciatic neuropathies shows that there can be many possible etiologies of sciatic nerve dysfunction, but that hip arthroplasty continues to be the leading risk factor. Sciatic nerve tumors are not commonly described in the literature and their definitive management remains unclear.     

Ultrasound Observation of the Sciatic Nerve and its Branches at the Popliteal Fossa: Always Visible, Never Seen

BACKGROUND: In studying patients with sciatic nerve (SN) varices the author found that the sciatic nerve and its major divisions, the tibial and peroneal nerves, could be readily identified on ultrasound imaging of the popliteal fossa. The sciatic nerve lies in the space between the popliteal vein and the small saphenous vein. OBJECTIVES: To confirm that the sciatic nerve can be identified on ultrasonography in patients with venous disease as well as in normal subjects. METHOD: Thirty unselected patients (60 limbs) attending for outpatient consultations were investigated by duplex ultrasound examination of the popliteal fossa. In 10 subjects varicose veins were present, in 20 no varices were visible on clinical examination. RESULTS: The sciatic nerve and its branches where visible and easily recognised in all cases. The sciatic nerve and the small saphenous vein lay in close proximity in cases with of small saphenous vein incompetence. CONCLUSIONS: Ultrasound identification of the sciatic nerve in the popliteal fossa allows assessment of its relationship with the adjacent veins. This technique may be useful in identifying the location of the nerve prior to surgical intervention for varices in the popliteal fossa as well as for endo-luminal occlusion procedures given the close proximity of the vein to the nerve. Sciatic nerve varices, tumours, extrinsic dislocation and nerve lesions may also be detected.     

A New Anterior Approach to the Sciatic Nerve Block

Background: Although several anterior approaches to sciatic nerve block have been described, they are used infrequently. The authors describe a new anterior approach that allows access to the sciatic nerve with the patient in the supine position.

Method: Sciatic nerve blocks were performed in 22 patients. A line was drawn between the inferior border of the anterosuperior iliac spine and the superior angle of the pubic symphysis tubercle. Next, a perpendicular line bisecting the initial line was drawn and extended 8 cm caudad. The needle was inserted perpendicularly to the skin, and the sciatic nerve was identified at a depth of 10.5 cm (9.5-13.5 cm; median and range) using a nerve stimulator and a 15-cm b-beveled insulated needle. After appropriate localization, either 30 ml mepivacaine, 1.5% (group 1 = knee arthroscopy; n = 16), or 15 ml mepivacaine, 1.5%, plus 15 ml ropivacaine, 0.75%, (group 2 = other procedures; n = 6) was injected.

Results: Appropriate landmarks were determined within 1.3 min (0.5-2.0 min). The sciatic nerve was identified in all patients within 2.5 min (1.2-5 min), starting from the beginning of the appropriate landmark determination to the stimulation of its common peroneal nerve component in 13 cases and its tibial nerve component in 9 cases. A complete sensory block in the distribution of both the common peroneal nerve component and the tibial nerve component was obtained within 15 min (5-30 min). A shorter onset was observed in patients who received mepivacaine alone compared with those who received a mixture of mepivacaine plus ropivacaine (10 min [5-25 min]vs. 20 min [10-30 min];P< 0.05). Recovery time was 4.6 h (2.5-5.5 h) after mepivacaine administration. The addition of ropivacaine produced a block of a much longer duration 13.8 h (5.2-23.6 h);P< 0.05. No complications were observed.     

人工全髋关节置换术中坐骨神经损伤的应用解剖学研究

目的　通过解剖位置的分析探讨全髋置换 (THR)术中坐骨神经 (SN)损伤的因素。方法　本组共 5 6具成年骨盆标本 ,对SN的来源及走行、SN与髋臼的关系进行测量分析 ,并对在THR术中拉钩及螺丝钉固定所致SN损伤 ,进行详尽测量分析。结果　测出SN至髋臼底的距离左侧为 6± 0 85mm ,右侧为 6± 0 71 2 5mm ;SN至髋臼缘的距离左侧为 1 3± 0 75mm ,右侧为 1 4± 0 0 6 2 5mm。SN在髋臼缘处周径左侧为 32± 0 2 75mm ,右侧为 31± 0 6 75mm。髋臼底至坐骨大孔的距离为左侧为 2 9± 0 36 2 5mm ,右侧为 2 9± 0 2 375mm。并确定拉钩及螺丝钉固定在 1～ 3点及 5～ 6点为安全区。结论　在THR术中陈旧髋臼骨折脱位、拉钩的位置不当、螺钉固定髋臼位置不当均可以损伤SN。     

Sciatic Nerve Block: a New Lateral Approach

The currently available methods for local anaesthetic block of the sciatic nerve are difficult to perform. Here we describe a new and easier technique for the block. The sciatic nerve is approached from the lateral side of the thigh with the patient lying supine and is identified by simple anatomical landmarks with the help of a nerve stimulator. The technique was found to be safe and effective in over 100 cases. It can be learnt quickly and is easily remembered.     

臀肌挛缩症松解术合并坐骨神经损伤

目的：探讨臀肌挛缩症松解术中坐骨神经损伤的危险因素，预防及处理方法，方法：1983年5月－2001年2月，对960例患者行臀肌挛缩症松解术，导致坐骨神经损伤，采用早期手术探查，显微技术外膜吻合，结果：960例中坐骨神经损伤2例，占0．21％，均经早期手术探查，显微外科技术吻合，效果良好。结论：对中、重度臀肌挛缩症松解时要逐层解剖，暴露清楚，注意坐骨神经变异，一旦损伤，应早期采用显微外科技术修复。     

化学去细胞同种异体神经移植物储存方法的初步研究

目的探索犬去细胞神经的最佳储存方法.方法采用真空封装辐照灭菌法深低温储存犬去细胞坐骨神经12个月,进行细菌学检查、一般组织学观察、免疫组化染色、透射电镜观察.结果储存过程中不会发生细菌污染,储存去细胞神经的延展性及神经外膜的韧弹性保持良好;其基本结构、神经基底膜及许旺细胞基底板层被保留;仍然保持为没有细胞髓鞘及其碎片的空的神经基质管.结论真空封装辐照灭菌法可有效储存去细胞神经1年.     

Iatrogenic Sciatic Nerve Palsy Following Hemiarthroplasty of the Hip

Abstract We report a rare complication following insertion of an uncemented hip prosthesis that resulted in posterior perforation of the femoral stem and a sciatic nerve palsy. To our knowledge, sciatic nerve palsy due to the femoral stem perforating the cortex has not been previously described.     

Above-Knee Replantation Following Traumatic Bilateral Amputation: Sciatic Nerve Transplantation

A 12-year-old boy who was overrun by a train, sustained traumatic bilateral above-knee amputation and a rupture of the symphysis. The left leg had multiple fractures and soft tissue injuries and amputation was necessary. The right one, although severely crushed, at the amputation site and with a MESS of 9, was replanted accepting some shortening and a soft tissue defect at the amputation site, employing saphenic vein grafts from the amputate (left leg) and an early free latissimus dorsi-flap. Septic complications at the amputation site were managed, and an autologous sciatic nerve graft was performed 8 months after the accident, employing the contralateral above-knee stump as the donor. Protective foot sole sensitivity was noticed after 2 years and 4 months and continued to improve. Further reconstructive procedures included ORIF of a femoral fracture in the contra-lateral stump. On the replanted leg proximal tibia corrective osteotomy and lateral collateral knee ligament reconstruction were performed. A follow-up of 7 years and 9 months demonstrates now a leg capable of full weight bearing and recovery of overall protective sensitivity. The boy made good psycho-social progress after difficulties and feels that the replanted leg is of significantly greater use to him than the hi-tech prosthesis on the other leg.     

移位髋臼骨折合并坐骨神经损伤

报告９例移位髋臼骨折合并坐骨神经损伤的治疗，其中单纯腓侧部损伤５例，联合腓侧部与胫侧部损伤４例。非手术治疗３例，手术治疗６例，平均随访２年，结果为手术治疗５例优良，１例可，非手术治疗２例疗效均不满意，表明手术治疗可有效复位骨折，去除神经外在压迫因素，对性质明确的神经损伤进行必要的松解和修复。本组坐骨神经损伤以腓侧部受累更为常见，腓侧部易受损伤的机理可能与某些局部解剖因素有关     

儿童臀部坐骨神经损伤

目的：探讨儿童臀部坐骨神经损伤的临床特点及处理。方法：回顾性研究分析139例儿童臀部坐骨神经损伤的临床资料。损伤原因中药物注射伤133例,锐器伤4例,钝器伤1例,手术误伤1例。分别进行神经松解术104例,神经吻合术4例,胫后肌转移2例,胫前肌转移1例,非手术治疗10例。结果：139例中除10例保守治疗者外,139例得到0.5-21年（平均8.4)的随访。神经松解术104例中优良者58例,占55.77%;神经吻合术4例良1例,占25%;肌腱转移术优良者16例,占76.19%,结论：和童臀部坐骨神经损伤以注射伤为最常见。诊断明确后应尽早手术进行神经探查松解,年龄愈小,手术越早效果越好,对断裂伤应积极认真进行端端吻合,对上述治疗无效者可通过肌腱转移术,对大龄儿童可采用踝关节融僵术改善踝关节功能。     

Continuous Popliteal Sciatic Nerve Block for Postoperative Pain Control at Home: A Randomized, Double-Blinded, Placebo-Controlled Study

Background: This randomized, double-blinded, placebo-controlled study investigated the efficacy of patient-controlled regional analgesia using a sciatic perineural catheter in the popliteal fossa and a portable infusion pump for outpatients having moderately painful, lower extremity orthopedic surgery.

Methods: Preoperatively, patients (n = 30) received a sciatic nerve block and perineural catheter in the popliteal fossa. Postoperatively, patients were discharged with both oral opioids and a portable infusion pump delivering study solution (0.2% ropivacaine or 0.9% saline) via the catheter for 3 days. Investigators and patients were blinded to random group assignment. Daily end-points included pain scores, opioid use and side effects, sleep quality, and symptoms of catheter- or local anesthetic-related complications.

Results: Ropivacaine (n = 15) infusion significantly reduced pain compared with saline (n = 15) infusion (P < 0.001). For example, the average pain at rest (scale: 0-10) on postoperative day 1 (median, 25th-75th percentile) was 4.0 (3.5-5.5) for the saline group, versus 0.0 (0.0-0.0) for the ropivacaine group (P < 0.001). Oral opioid use and related side effects were significantly decreased in the ropivacaine group. For example, on postoperative day 1, median tablet consumption was 8.0 (5.0-10.0) and 0.0 (0.0-0.0) for the saline and ropivacaine groups, respectively (P < 0.001). Sleep disturbance scores were more than 10-fold greater for saline administration than for ropivacaine infusion (P < 0.001). Overall satisfaction was significantly greater in the ropivacaine group. Other than two inadvertent catheter dislodgements, no catheter- or local anesthetic-related complications occurred.     

Correlation between Evoked Motor Response of the Sciatic Nerve and Sensory Blockade

Background: Incomplete sensory blockade of the foot after sciatic nerve block in the popliteal fossa may be related to the motor response that was elicited when the block was performed. We investigated the appropriate motor response when a nerve stimulator is used in sciatic nerve block at the popliteal fossa.

Methods: Six volunteers classified as American Society of Anesthesiologists' physical status I underwent 24 sciatic nerve blocks. Each volunteer had four sciatic nerve blocks. During each block, the needle was placed to evoke one of the following motor responses of the foot: eversion, inversion, plantar flexion, or dorsiflexion. Forty milliliters 1.5% lidocaine was injected after the motor response was elicited at < 1 mA intensity. Sensory blockade of the areas of the foot innervated by the posterior tibial, deep peroneal, superficial peroneal, and sural nerves was checked in a blinded manner. Motor blockade was graded on a three-point scale. The width of the sciatic nerve and the orientation of the tibial and common peroneal nerves were also examined in 10 cadavers.

Results: A significantly greater number of posterior tibial, deep peroneal, superficial peroneal, and sural nerves were blocked when inversion or dorsiflexion was seen before injection than after eversion or plantar flexion (P < 0.05). Motor blockade of the foot was significantly greater after inversion. Anatomically, the tibial and common peroneal nerves may be separate from each other throughout their course. The sciatic nerve ranged from 0.9-1.5 cm in width and was divided into the tibial and common peroneal nerves at 8 +/- 3 (range, 4-13) cm above the popliteal crease.     

Neurophysiologic Actions and Neurological Consequences of Veratridine on the Rat Sciatic Nerve

Background: The quest for a drug that would provide analgesia with minimal motor deficiency, through the selective inhibition of impulses in small-diameter fibers, was brightened by a previous report of veratridine's C-fiber-selective actions on the isolated rabbit vagus nerve. The goal of the present research was to demonstrate the same actions on rat sciatic nerve in vitro and to observe the functionally differential blockade in the rat in vivo.

Methods: Sciatic nerves were removed from rats, mounted in a recording chamber, wherein a 1-cm length of the ensheathed nerve was superfused with the plant alkaloid veratridine (2 micro Meter) in bicarbonate-buffered Liley's solution, and the compound action potential (CAP) was stimulated supramaximally to give A- and C-fiber elevations. Onset, steady-state, and recovery from veratridine effects were assayed for a range of stimulus frequencies. Open-field behavior and quantitative neurological assessments of proprioception, motor function, and nociception were tested in 15 trained rats after injection near the sciatic nerve of 0.1 ml veratridine at 0.5, 0.7, and 1.0 mM each plus epinephrine (1:200,000).

Results: Veratridine inhibited the C-fiber component of the CAP in a frequency-dependent manner. At 0.1 Hz the CAP was 65% of the control amplitude, 50% at 0.5 Hz, and 40% at 5 Hz. A-fiber elevations were unattenuated at stimulus frequencies as high as 50 Hz. Steady-state inhibition was reached 5 min after drug administration, and recovery from the effects was 30% complete by 15 min of drug washout. Proprioception, measured as a "hopping" or "placing" reaction, was inhibited dose dependently by maximum degree and for durations of, respectively, 0.5 mM, 61%, 180 min; 0.7 mM, 100%, 360 min; and 1 mM, 100%, 420 min. Extensor postural thrust, as a measure of motor function, was inhibited by and for 0.5 mM, 77%, 240 min; 0.7 mM, 99%, 390 min; and 1 mM, 100%, 420 min. Analgesia, as a prolonged withdrawal latency to a noxious thermal stimulus, had the following profile: 0.5 mM, 10%, 30 min; 0.7 mM, 52%, 150 min; and 1 mM, 66%, 150 min.     

神经牵拉延长器修复神经缺损的实验研究

探讨神经牵拉延长器修复神经缺损,为临床应用提供依据。方法：健康家兔３０只,分３组,右侧坐骨神经造成１．０ｃｍ缺损,Ａ组：自制神经牵拉延长器延长,二期端－端缝合;Ｂ组：神经原位移植;Ｃ组：直接拉扰缝合。术后不同时期分别进行电生理、组织学、神经纤维计数等检查。     

臀部坐骨神经药物注射伤的手术治疗

目的 探讨臀部坐骨神经药物注射伤的发生机制、临床特点、治疗和预防。方法 经手术治疗并有随访结果的１２９例中，坐骨神经完全损伤１２例，不完全损伤２４例；坐骨神经的肢神经支完全及不完全损伤各１例；腓神经支完全损伤８６例，不完全损伤５例。１２３例做神经内、外松解术，１例做神经外膜切开减压冲洗术，５例未探查神经而行径后肌转移功能重建术。结果 平均随访８年５个月，神经松解减压术优良率为５７．２６％，功能重建