Association Between Deep Vein Thrombosis and the Temperature at the Popliteal Fossa During Cement Curing in Total Knee Arthroplasty

The temperature at the popliteal fossa during cement curing and its relationship with deep vein thrombosis (DVT) in total knee arthroplasty (TKA) has not been investigated. Fifty-six consecutive patients who underwent primary TKA were recruited. The temperatures at the popliteal fossa were measured during bone cement exothermic polymerization. Postoperative operated leg ascending venographies were performed 5 days after TKA for screening of DVT. The maximum temperatures were 32.5°C ± 1.0°C at the popliteal fossa during cement curing. No significant difference was found of the maximum temperatures in the popliteal fossa between the non-DVT and DVT groups. The present study indicated that the heat resulting from polymerization of the cement may not be a possible cause of damage to the veins surrounding the knee, and it may have no relationship with DVT.     

一期后路截骨矫形术治疗重度脊柱畸形术后的并发症分析及处理

 目的 探讨一期后路截骨矫形术治疗重度脊柱畸形术后并发症原因及处理。方法 回顾性分析2006年9 月至2013年5月,采用一期后路截骨矫形内固定术治疗147例重度脊柱畸形患者资料,其中17例术后发生病发症,男5例,女12例;年龄14～51岁,平均22.6岁;先天性脊柱侧凸11例,先天性脊柱后凸4例,先天性脊柱侧后凸2例;术前主弯 侧凸Cobb角85°~160°,平均109°;后凸Cobb角65°~152°,平均104°。术前2例患者有神经症状,美国脊髓损伤协会ASIA分级均为D级。手术均采用椎弓根钉棒系统矫形固定,其中采用Smith?Petersen 截骨术2例、经椎弓根截骨术11例、全脊 椎截骨术4例。结果 17例出现并发症,并发症发生率为11.6%(17/147)。其中椎弓根螺钉置入椎管2例、截骨端合拢压 迫及牵拉神经2例、截骨处残留骨块压迫神经1例、急性脊髓损伤2例、感染2例、断棒及脱帽3例、肠系膜上动脉综合征5 例。术后7例发生神经系统并发症,其中2例由术前ASIA分级D级变为C级,5例由神经功能正常变为C级2例、D级3 例。采用再次手术调整钉棒、应用甲基泼尼松龙、神经营养药物、取出内固定、抗感染、翻修换棒及对症处理,15例完全恢复,2例好转。结论 严重脊柱畸形一期后路截骨矫形术后会出现神经系统及断棒、脱帽、肠系膜上动脉综合征等并发症。为避免发生并发症,术中应提高椎弓根钉置入的准确性,合理安置螺钉数量及位置,截骨端牵拉加压应适度,并彻底 咬除截骨端骨块,术后密切观察肢体感觉及运动变化情况,及时手术探查并解除神经致压因素,同时给予激素冲击、神经营养等药物,术后早期需佩戴合适支具,避免暴力撞击手术部位。     

椎管内修复臂丛神经损伤的解剖及临床应用研究

目的观察通过打开椎管找到残存的臂丛神经根并进行神经修复的可行性。方法甲醛溶液固定的成人尸体标本15具30侧，测量C5-T1，神经前根椎间孔段的直径、长度和有髓神经纤维计数。选择5例臂丛神经损伤患者，2例为椎孔处刀刺伤，3例为闭合性创伤。自受伤到椎管内探查的时间为3-6个月，平均4个月。CTM显示部分已损伤的神经根其椎管内神经前后根仍存在，而锁骨上臂丛神经探查在椎间孔外找不到相应的具有正常结构的神经根近端，通过打开椎管将椎管内残存的神经根用腓肠神经桥接进行神经修复。结果C5-T1，神经前根的有髓神经纤维数目为4000-6000根，椎间孔段的长度为11～14mm，外径为1．2～1．5mm。5例患者的椎管内均找到了具有正常结构的神经根近端，其中C5神经根3例，C5、C6神经根1例，C7神经根1例。C5修复肩胛上神经和C5神经远端各1例，C5修复正中神经内侧头1例，C7修复内侧束1例，C5、C6分别修复上干后股、肌皮神经1例。术后随访38--46个月，平均42个月。5例患者其修复神经所支配肌肉的肌力分别达3-4级。结论对于神经根在椎间孔处断裂的臂丛神经损伤，可通过打开椎管找到损伤神经根的近端，为臂丛神经根性损伤的修复提供理想的动力神经源，有利于臂丛神经治疗效果的提高。     

Intraspinal grafting procedures: spinal cord effects induced in the adult rat: a clinical, histopathological, and immunohistochemical study

OBJECTIVE: Intraspinal grafting procedures using peripheral nerve grafts (PNG) or collagen guidance channels (CGC) have been recently used to treat brachial plexus injuries in humans and spinal cord injuries in animals. This study examined the effects of these procedures in the adult rat. METHODS: In adult rats, we performed an avulsion of left C5, C6, and C7 nerve roots, followed by a myelotomy of the left ventrolateral aspect of the spinal cord between C5 and C6. The rats were subsequently assigned to one of three groups: group A (n = 10), no additional procedure; group B (n = 10), implantation of a PNG following myelotomy; group C (n = 10), implantation of a CGC. Clinical evaluation was postoperatively assessed. Rats were euthanized at day 6 or 21. Spinal cord lesions induced by surgery were assessed by measuring depth and rostrocaudal extent. Reactive astrogliosis, as a reaction to neuroglial damage, was assessed by revealing the glial fibrillary acidic protein with immunochemistry method. RESULTS: No animal showed persistent neurological deficit at day 21. The depth and rostrocaudal extent of tissue damage was comparable in all groups at days 6 and 21. At day 6, the astrocytic reaction observed at the myelotomy/implantation site was statistically stronger in group C (CGC). At day 21, the astrocytic reaction became identical in all groups. CONCLUSION: This study shows that grafting a PNG or a CGC into the spinal cord does not create significant additional iatrogenic effects and can be used in repair strategies to treat nerve root avulsions or spinal cord injuries.     

Pathophysiology of sciatica

The exact pathophysiologic mechanisms behind sciatica are incompletely known; however, compression of spinal nerve roots is known to be correlated to both pain and neural dysfunction in a segmental distribution of that specific nerve root. Compression per se may impair the transport of nutrients to the nerve tissue in such a way that affects the nerve root function. There also might be a local affect on nerve roots or root sleeves by substances leaking from the degenerated intervertebral discs.     

Effects of preservation and sterilization on cortical bone grafts

The effects of preservation and sterilization on the structural properties of cortical bone were investigated. Specimens of cortical bone from rat tibiae were frozen (–70°C for 28 days), freeze-dried, irradiated (1, 5, 25 and 50 kGy) or autoclaved (at 134°C for 3 or 5 min), and examined by scanning electron microscopy. Cryopreservation and irradiation had no deleterious effects on the surface structure of the cortical bone. Freeze-drying caused microcracks running parallel to the mineralized fiber bundles. After autoclaving, a time-dependent distension, swelling and amalgamation of the fibrillary matrix was observed. This denaturation of the organic matrix was more pronounced after 5 min than 3 min autoclaving. The alterations of the fibrillary structure described above might be due to a preservation- and sterilization-induced decrease of the biological and biomechanical potential of bone grafts.Supported by DFG grant     

Pathology of the peripheral nervous system

This review deals with papers on important topics in peripheral nerve surgery. Some new diagnostic tools and microsurgical procedures are brought to the attention of neurosurgeons. The first four papers are related to new surgical strategies in treating brachial plexus injury (BPI), particularly root avulsion. Concepts based on experimental studies are applied to clinical practice. Re-establishment of the continuity of interrupted spinal roots or reimplantation of the avulsed spinal roots into the spinal cord are attempted. The authors demonstrate how computed tomography (CT) myelography can be used to plan surgical treatment correctly. The use of reinnervated free-muscle transfer after complete brachial plexus C5-T1 root avulsion is described and critically evaluated. The results obtained after repair of interrupted spinal roots or reimplantation of avulsed spinal roots into the spinal cord are not as clear as described by the authors. Further experimental studies and surgical outcomes are necessary before accepting the efficacy of such surgical procedures in BPI. Reinnervated free-muscle transfer appears to be a promising method for treating such severe lesions. The fifth paper is a case report in which the trapezius branch of the spinal accessory nerve was neurotized with the dorsal branch of the third cervical nerve. This procedure was performed after an injury to the spinal accessory nerve in the neck. The proximal stump of the spinal accessory nerve was available only intracranially. Using this procedure, the risk related to an intracranial approach to the spinal accessory nerve is avoided. A review of one case of primitive neuroectodermal malignant tumor of the median nerve is used to discuss some controversies related to the treatment of malignant tumors involving peripheral nerves.     

Heat generation and heat protection in methylmethacrylate cementation of vertebral bodies

Summary For metastatic disease of the spine, anterior operations on the vertebral bodies often include methylmethacrylate cementation. The cement curing process may produce high temperatures in the surroundings, as demonstrated in joint replacement surgery, and there is a risk of thermal injury to the spinal nerves. In cadavers, we studied the heat arising during curing of cement on the dural sac, and the temperature of the cement surface was measured when the vertebral body was reconstructed using acrylic cement in the same way as in tumor surgery. The temperature increase on the surface of the dural sac during polymerization was between 4° and 12°C, depending on the amount of protection. Only a moderate temperature elevation was measured on the surface of the dural sac, provided that the posterior cortex of the vertebra was retained together with 0.5 cm of the spongious bone or a silicone membrane.     

Die Temperaturentwicklung verschiedener Knochenzemente während des Abhärtungsvorganges

Zusammenfassung Wir führten erneut Untersuchungen zur berührungslosen Messung der Polymerisationstemperaturen abhärtender Knochenzemente mit Hilfe der Infrarotthermographie durch. An geformten Kugeln und Platten wurden die Temperaturverlaufskurven von 3 verschiedenen Knochenzementen (CMW Bone Cement, Palacos R und Simplex) experimentell bestimmt. Dabei ergaben sich folgende Resultate: Die durchschnittlichen Höchstwerte aller Versuche betrugen beim CMW Bone Cement 121°C, beim Palacos R 108°C und beim Simplex 116°C. Die Wärmeentwicklung hängt nicht ab vom Verhältnis Oberfläche zum Volumen des untersuchten Zementes. Die Dauer bis zum Erreichen der Maximaltemperaturen und damit die Abhärtungszeit war für die untersuchten Zemente unterschiedlich. Sie betrug beim CMW Bone Cement durchschnittlich 7 min 40 sec, beim Palacos R 8 min und beim Simplex 12 min. Alle erreichten Spitzentemperaturen lagen weit über der von Lehnartz mit 56°C angegebenen Coagulationstemperatur des Eiweißes.Wir halten auf Grund unserer neueren Untersuchungen weiterhin daran fest, daß die Polymerisationstemperaturen der Knochenzemente, die in lebendes Gewebe eingebracht werden, zu Thermonekrosen führen müssen.

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The temperature evolution of different bone cements during polymerisation

Summary New investigations were made for determination of the radiation-temperatures of cold-curing acrylic cements during the polymerisation with the help of thermovision. On formed pellets and plates the temperature curve of 3 different bone cements (CMW Bone Cement, Palacos R and Simplex) were determined by experiment. This resulted in the following: the average maximum degrees of all experiments resultes on CMW Bone Cement 121°C, Palacos R 108°C and Simplex 116°C. The temperature evolution does not depend from the comparison surface to volume of the investigated cement. The duration up till achieving the maximum temperature and herewith the time of hardening was different from the investigated cements. She showed at CMW Bone Cement average 7 min 40 sec, at Palacos R 8 min and at Simplex 12 min. All determined maximum temperatures were far over the coagulation temperature of albumin, given by Lehnartz with 56°C.On basis of our more recent investigations we further believe, that the polymerisation temperatures of bone cement, which is put in living tissues, must lead to thermo-necrosis.

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Herrn Prof. Dr. med. Dr. h.c. E. Derra zum 70. Geburtstag gewidmet.     

臂丛神经根性撕脱伤后神经根回植的实验研究

目的探讨臂丛神经根性撕脱伤后，神经根回植脊髓对前角运动神经元的挽救效应及作用机制，观察回植后神经根的生长情况。方法成年Wistar大鼠30只，随机分两组，每组15只。取两组大鼠左侧为正常对照侧，不作任何处理；右侧进行模型制备。进行C4-6右侧椎板减压，于椎管内硬膜外撕脱C5、6神经根。实验组将C5神经前根回植入脊髓前角，用11—0无创缝线缝合2针，后根旷置，C5神经根埋入周围肌肉；对照组将撕脱的C5、6神经根埋入肌肉。术后2、4、6、8及12周取材，C6脊髓HE染色，观察脊髓前角运动神经元的形态和数量的变化；C6神经根作硝酸银染色，观察神经纤维的再生情况。结果两组大鼠术后均表现为右上肢上干瘫痪，余肢体活动正常。对照组撕脱的神经根与周围肌肉粘连；实验组神经根植入脊髓处有较多瘢痕组织粘连，未见神经根从脊髓上脱落。各时间点HE染色显示，实验组运动神经元胞体萎缩，部分运动神经元水肿，尼氏体减少或消失；对照组神经细胞胞体缩小。术后各时间点对照组脊髓前角运动神经元成活率分别为60．9％±5．8％、42．3％±3．5％、30．6％±6．1％、27．5％±7．9％及20．4％±6．8％，实验组为67．1％±7．4％、56．3％土4．6％、48．7％±8．8％、44．2％±5．5％及42．5％±8，3％，差异有统计学意义（P〈0．01）。硝酸银染色显示，实验组C6神经根硝酸银染色显示前角运动神经元能通过轴突再生进入回植的神经根内；对照组显示为神经纤维的退变，有髓神经纤维数目减少。结论臂丛神经根性撕脱伤后前根回植脊髓后，能够明显减少前角运动神经元的变性死亡。神经根回植后，运动神经元能通过轴突再生进入回植的神经根内，并有新生的有髓神经纤维生长。     

Shoulder reanimation in posttraumatic brachial plexus paralysis

Introduction

Posttraumatic brachial plexus paralysis invariably involves the upper roots leading to paralysis of the shoulder region musculature. Early neurotisation of the suprascapular and the axillary nerve should be one of the priorities in plexus reconstruction in order to reanimate the shoulder.

Patients and methods

From 1998 to 2007, 78 patients with posttraumatic brachial plexus palsy were operated in our department. Forty-three patients presented with supraclavicular lesions with involvement of C5 and C6 roots in all cases. Reconstruction of the shoulder function was achieved with neurotisation of the suprascapular nerve in 41 patients. Extraplexus donors were utilised in 34 patients, while intraplexus donors via nerve grafts in 7 patients. Neurotisation of the axillary nerve was performed in 25 patients, utilising intraplexus donors in 16 patients, extraplexus donors in 4, and combination of intraplexus and extraplexus donors in 5 patients.

Results

Suprascapular nerve neurotisation gave good or excellent results (supraspinatus > M3+ or shoulder abduction > 40°) in 35 patients. Intraplexus donors regained good or excellent function in 5 out of 6 patients (83%), while extraplexus neurotisations achieved good or excellent function of the supraspinatus in 30 out of 34 patients (88%). Axillary nerve neurotisation offered good or excellent results (deltoid > M3+ or shoulder abduction > 60°) in 14 patients (58%). Direct neurotisation of the axillary nerve via the motor branch for the long head of the triceps gave shoulder abduction of >110°, as well as external rotation of >30° in 3 out of 5 patients. Combined neurotisation of suprascapular and axillary nerves gave the best outcome achieving shoulder abduction of >60° as well as external rotation of >30°.

Conclusions

Shoulder reanimation should be one of the first priorities in brachial plexus reconstruction. Early neurotisation of the suprascapular, and if possible the axillary nerve offers the best outcome.     

Vascular and neural pathology of lumbosacral spinal stenosis

During a study of the intrinsic vasculature of the lumbosacral spinal nerve roots in cadavers, a typical case of spinal stenosis was encountered. A review of the antemortem anamnesis revealed that this patient had had an intermittent claudication of the cauda equina. Investigation of the concomitant vascular and histopathological alterations of the affected nerve roots suggested that the claudication may have resulted from ectopic nerve impulse discharges elicited by rapid changes in the blood supply following exertion. The unexpectedly slight apparent neural deficit relative to observed root damage may be attributed to a neuronal plasticity within the spinal cord that permitted functional compensations to develop during the slow acquisition of the chronic nerve root pathology.     

Excision of high sacral giant cell tumor and reconstruction with bone cement

We report the case of a woman who had a right sacroiliac giant cell tumor with S1 nerve root involvement. No specific functional defects were noted after she underwent combined anterior abdominal and posterior sacral approaches for tumor excision and reconstruction with bone cement. Our goal is to determine whether or not, with carefully planned procedures and delicate nerve protection, the biomechanical stability of the sacrum was affected after the tumor resection. We believe that bone cement impaction can be considered as an alternative reconstructive method instead of high-priced, complicated fixation devices or allografts that are not readily available.     

In vitro temperature evaluation during cement augmentation of proximal humerus plate screw tips

Background

The treatment of proximal humerus fractures in patients with poor bone quality remains a challenge in trauma surgery. Augmentation with polymethylmethacrylate (PMMA) cement is a possible method to strengthen the implant anchorage in osteoporotic bone and to avoid loss of reduction and reduce the cut-out risk. The polymerisation of PMMA during cement setting leads, however, to an exothermic reaction and the development of supraphysiological temperatures may harm the bone and cartilage. This study addresses the issue of heat development during augmentation of subchondrally placed proximal humerus plate screws with PMMA and the possible risk of bone and cartilage necrosis and apoptosis.

Methods

Seven fresh frozen humeri from geriatric female donors were instrumented with the proximal humerus interlocking system (PHILOS) plate and placed in a 37 °C water bath. Thereafter, four proximal perforated screws were augmented with 0.5 ml PMMA each. During augmentation, the temperatures in the subchondral bone and on the articular surface were recorded with K-type thermocouples. The measured temperatures were compared to threshold values for necrosis and apoptosis of bone and cartilage reported in the literature.

Results

The heat development was highest around the augmented tips of the perforated screws and diminished with growing distance from the cement cloud. The highest temperature recorded in the subchondral bone reached 43.5 °C and the longest exposure time above 42 °C was 86 s. The highest temperature measured on the articular surface amounted to 38.6 °C and the longest exposure time above 38 °C was 5 min and 32 s.

Conclusion

The study shows that augmentation of the proximal screws of the PHILOS plate with PMMA leads to a locally limited development of supraphysiological temperatures in the cement cloud and closely around it. The critical threshold values for necrosis and apoptosis of cartilage and subchondral bone reported in the literature, however, are not reached. In order to avoid cement extravasation, special care should be taken in detecting perforations or intra-articular cracks in the humeral head.     

Treatment of Painful Osteoporotic Vertebral Fractures with Percutaneous Vertebroplasty or Kyphoplasty

Vertebral fracture is the most common complication of osteoporosis. It results in significant mortality and morbidity, including prolonged and intractable pain in a minority of patients. Vertebroplasty and kyphoplasty, procedures that involve percutaneous injection of bone cement into a collapsed vertebra, have recently been introduced for treatment of osteoporotic patients who have prolonged pain (several weeks or longer) following vertebral fracture. To determine the details of the procedures and to gather information on their safety and efficacy, we performed a MEDLINE search using the terms “vertebroplasty” and “kyphoplasty.” We reviewed reports of these procedures in patients with osteoporosis. We supplemented the articles found with other papers known to the authors and with presentations at national meetings. Randomized trials of vertebroplasty and kyphoplasty have not been reported. Case reports suggest that these procedures are associated with pain relief in 67% to 100% of cases. Short-term complications, mainly the result of extravasation of cement, include increased pain and damage from heat or pressure to the spinal cord or nerve roots. Proper patient selection and good technique should minimize complications, but rarely, decompressive surgery is needed. Long-term benefits have not yet been shown, but potentially include prevention of recurrent pain at the treated level(s) with both procedures, and, with kyphoplasty, reversal of height loss and spinal deformity, an improved level of function, and avoidance of chronic pain and restriction of internal organs. Possible long-term complications, again not fully evaluated, include local acceleration of bone resorption caused by the treatment itself or by foreign-body reaction at the cement–bone interface, and increased risk of fracture in treated or adjacent vertebrae through changes in mechanical forces. Controlled trials are needed to determine both short-term and long-term safety and efficacy of vertebroplasty and kyphoplasty. Both procedures may be useful for osteoporotic patients who have prolonged pain following acute vertebral fracture. Until there is conclusive evidence for efficacy and long-term safety, these procedures should be done only in carefully selected patients, only by experienced operators with appropriate high-quality imaging equipment, and ideally at centers that are participating in controlled trials. Received: 26 January 2001 / Accepted: 21 February 2001     

Intraoperative Temperaturmessungen in der Hüftchirurgie während der Polymerisation des Knochenzementes Palacos

Zusammenfassung Bei der Implantation von Hüftgelenk-Totalendoprothesen unter Verwendung des Knochenzements Palocos wird während der Polymerisation der Palacosflüssigkeit Wärmeenergie freigesetzt. Nach am Menschen in vivo durchgeführten Temperaturmessungen tritt an der Grenzfläche zwischen Palacos und Knochen im Bereich der Pfanne eine mittlere Maximaltemperatur von 50,4°C, im Bereich des Prothesenschaftes eine mittlere Maximaltemperatur von 45,2°C auf.Wegen der hohen Coagulationstemperatur des Knochenkollagens von 72°C bei hoher spezifischer Wärme und geringer Wärmeleitfähigkeit des Knochens ist mit thermischen Schädigungen in der Hüftgelenkprothetik nicht zu rechnen.Spezielle Maßnahmen zur Kühlung sind nicht notwendig; auf möglichst sparsames Auskürettieren der Knochen sollte jedoch Wert gelegt werden.

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Intraoperative measuring of temperature in the surgery of hip during the polymerisation of the bone cement Palacos

Summary By the implantation of hip-joint endoprothesis under application of Palacos bone cement, thermal energy is released during the polymerisation of the palacos fluid. After measuring the temperature in human hip-surgery, an average maximum temperature of 50.4°C showed on the interface between palacos and bone in the socket area, and at the femur a temperature of 45.2°C was registered.Because of the high coagulation temperature of the bone collagen (72°C) by a high specific heat and low thermal conductivity of the bone, thermal damage is improbable.Special measures for cooling are unnecessary, care should, however, be paid to economical curettage of the bones.

     

大鼠肱肌肌支的脊髓神经根定位

目的 比较逆行示踪法及肌电图检测法在定位肱肌肌支及肱肌脊髓神经根起源中的价值,并探讨将肌电图检测法运用于定位人类肌皮神经肱肌肌支脊髓神经根起源的可能性.方法 在大鼠臂丛神经根切断-保留模型中运用神经元逆行示踪法定位肱肌肌支及肱肌的脊髓神经根起源;通过分析刺激大鼠各臂丛神经根时肱肌记录到的CMAP指标定位肱肌肌支及肱肌的脊髓神经根起源.结果 大鼠桡神经肱肌肌支的运动纤维主要来源于C7神经根,大鼠肌皮神经肱肌肌支的运动纤维主要来源于C5、6神经根;在定位大鼠肱肌的脊髓神经根起源时,肌电图法与逆行示踪法的检测结果基本一致.结论 通过分析逆行示踪和肌电图检测的结果,能够精确定位大鼠特定神经、肌肉的脊髓神经根来源;在临床研究中,肌电图检测法可以用于定位人类肌皮神经肱肌肌支的脊髓神经根起源.     

Reconstruction of finger and elbow function after complete avulsion of the brachial plexus

Simultaneous reconstruction of elbow and finger function with free muscle and nerve transfers after complete avulsion of the brachial plexus (nerve roots C5 to T1) and its long-term results are presented. The basic procedure combined free or vascular pedicle latissimus dorsi muscle transfer with reinnervation by the spinal accessory nerve to obtain elbow and finger flexion, intercostal nerve transfer of the radial nerve to activate elbow and wrist extensors, and suture of the supraclavicular nerve or intercostal sensory rami to the median nerve to restore hand sensibility. Six patients had some or all of these procedures. Postoperative follow-up ranged from 2 to 5 years. Elbow function was restored completely, and some finger flexion was achieved in all cases, although a dynamic splint was necessary to straighten the digits. Patients have continued to improve in grasp power and finger control. This procedure appears to be promising for the restoration of basic hand function in severely handicapped patients.     

椎管内胸神经根移位至腰神经根的解剖学研究

目的 了解椎管内T9～12神经根移位修复L2～4神经根、恢复截瘫后股四头肌功能的解剖学基础.方法 5 具成人尸体标本,其中男性2具,女性3具.完全显露胸段及腰段椎管,观察T9～L4神经根在脊髓上发出的部位,T12及L1椎体水平与椎管内各神经根之间的关系;测量T9～L4神经根在椎管内的长度,T9～L4神经根的直径,T9～L4各神经根起始部之间的距离,T9～12神经根自硬脊膜穿出到L2椎体中部水平的距离.结果 T9神经根发自T9椎体中部,L4神经根发自L2椎体中部;T9～L4神经根在椎管内的长度均值分别为16.12、22.97、30.43、43.47、56.02、70.03、88.70和113.65mm.T9～L4神经根的直径均值分别为2.45、2.04、1.96、2.18、2.32、2.56、3.10和3.26 mm.各神经根起始部之间的距离均值分别为22.87、25.08、28.47、27.38、29.78、31.93和31.00 mm.T9～12神经根自硬脊膜穿出到L2椎体中部水平的距离均值分别为118.69、95.82、70.74和42.27 mm.结论 T9～12神经根均可以作为动力神经;可以将L2椎体的中部作为受体神经吻合平面修复L2～4神经根.     

Neurologic complications of surgery for cervical compression myelopathy.

Neurologic complications resulting from surgery for 384 cases of cervical myelopathy (cervical soft disc herniation, spondylosis, ossification of the posterior longitudinal ligament) were reviewed. Surgical procedures performed included 134 anterior interbody fusions (Cloward or Robinson-Smith technique), 70 subtotal corpectomies with strut bone graft, 85 laminectomies, and 95 laminoplasties. Twenty-one patients (5.5%) sustained neurologic deterioration related to surgery. The deterioration was classified into two types on the basis of the neurologic signs observed: deterioration of spinal cord function or of nerve root function. Manifestations of the former varied from weakness of the hand to tetraparesis. Paralysis of the deltoid and biceps brachii muscles was an exclusive feature of deterioration in the nerve root group. Causes of this paralysis included malalignment of the spine related to graft complications, and a tethering effect on the nerve root following major shifting of the spinal cord after decompression. The causes of deterioration of the cord function included spinal cord injury during surgery, malalignment of the spine associated with graft complication, and epidural hematoma.