Three-dimensional analysis of computed tomography-based navigation system for total knee arthroplasty: the accuracy of computed tomography-based navigation system

We evaluated the postoperative alignment of 37 primary total knee arthroplasties performed using a computed tomography–based navigation system (Vector Vision Knee 1.5; Brain Lab, Germany) with a new 3-dimensional analysis. The mean coronal femoral angle was 89.0° ± 1.4° (85.5°-92.8°), and the coronal tibial component was 89.2° ± 1.0° (87.4°-91.6°). The hip-knee-ankle angle was observed to be 178.2° ± 1.5° (173.9°-181.8°). The external rotational alignment of the femoral component relative to the surgical epicondylar axis was −0.5° ± 1.7° (−3.2° to 3.4°). The results demonstrated that a computed tomography–based navigation system provided a reasonably satisfactory component alignment. The discrepancy between the 2-dimensional and 3-dimensional evaluations was 1.0° ± 0.9° (0.1°-3.4°). Three-dimensional analysis is necessary to evaluate the accuracy of the navigation system.     

后路减压枕颈融合与植骨治疗颅底凹陷症

目的 评价颈后路减压后枕颈融合内固定加自体髂骨移植治疗颅底凹陷症的疗效.方法 采用颈后路枕下充分减压+枕颈融合内固定及自体髂骨移植术治疗21例颅底凹陷症患者,术后所有患者给予颈托固定3个月及康复锻炼.结果 本组患者术后影像学检查显示枕骨大孔处脊髓已得到充分减压,平均随访时间14个月,术后JOA评分平均14.1分,明显大于术前的8.1分,改善率为67.4%.结论 颈后路减压后枕颈融合内固定加自体髂骨移植是治疗颅底凹陷症的一种有效方法,可改善患者神经症状,提高生活质量.     

Anatomical relations in the carpal tunnel: a computed tomographic study

Computed tomography of the carpal tunnel was performed in the hands of both patients and controls in a neutral position, in flexion and in extension. The median nerve was not compressed between the long flexors and the flexor retinaculum in either flexion or extension of the wrist. In flexion, the nerve usually moved dorsally, away from the flexor retinaculum. No difference could be found between the cross-sectional area of the carpal tunnel between patients and controls.     

Halo traction in basilar invagination: technical case report

BACKGROUND: In the management of basilar invagination, traction therapy may help by pulling down the odontoid process away from the brain stem that may result in clinical and radiological improvement. We aimed to discuss the role of the halo vest apparatus traction on the reduction of severe anterior compression pathologies in basilar invagination. CASE DESCRIPTION: We describe a simple and safe cervical traction method by the halo vest apparatus that is followed by rigid posterior occipitocervical fixation and foramen magnum decompression in a patient who presented with basilar invagination and symptoms of severe brain stem compression. An MR-suitable halo vest apparatus was used for reduction of the deformity. The reduction of the basilar invagination was achieved gradually by distracting the halo crown in stages. CONCLUSION: The halo vest apparatus can be safely used in complex craniocervical junction anomalies. An effective cervical traction can be performed in basilar invagination, and reduction of the deformity may be achieved without the risk of overdistraction. In some cases, even partial reduction of the deformity may facilitate brain stem and spinal cord relief without any need of posterior decompression. Patients may benefit from ambulatory functions because bed rest is eliminated in this procedure. Neurovascular structures and the degree of the reduction can be observed on MRIs when an MR-suitable device is used.     

Ventral compression in adult patients with Chiari 1 malformation sans basilar invagination: cause and management

Background  

A small subset of patients with adult Chiari I malformation without basilar invagination (BI) and instability show ventral cervicomedullary distortion/compression and have symptoms pertaining to that. The cause of this ventral compression remains speculative. Additionally, it is unclear if these patients would require ventral decompression with posterior fusion or only posterior decompression would suffice.     

先天性颅底凹陷伴寰枢椎脱位患者的手术疗效与影响因素分析

目的 探讨先天性颅底凹陷合并寰枢椎脱位患者的手术疗效及影响因素.方法 回顾性分析2004年5月至2010年8月因先天性颅底凹陷合并寰枢椎脱位行手术治疗的120例患者资料,采用问卷调查、电话和门诊复查进行随访,93例获得有效随访.患者均采用单纯后路术中直接撑开复位椎弓根螺钉内固定技术治疗.所有患者行术前、术后X线、CT扫描及三维重建、MRI检查.通过比较术前、术后日本骨科协会(JOA)评分、齿状突尖距Chamberlain线的垂直距离(CL)和寰齿间距(ADI),评判患者疗效.所得数据结果采用配对t检验和Pearson相关分析.结果 93例患者的随访时间为24～ 99个月,平均46.5个月.末次随访时,79例(84.9％)症状好转,7例(7.5％)症状稳定、4例(4.3％)加重,3例(3.2％)术后死亡.没有脊髓髓内信号改变的患者,术后恢复最好;同时受到前方齿状突和后方枕骨大孔-寰椎后缘压迫的患者,恢复效果最差(F =3.987,P＜O.O1).术后影像显示87例患者(93.5％)植骨融合良好,减压充分.手术死亡3例分别死于后颅窝血肿、基底动脉血栓和不明原因各1例.结论 单纯后路术中直接撑开复位螺钉内固定技术是一项简单、有效和安全的技术;齿状突脱位引起的前方压迫和后方枕骨大孔后缘-寰椎后弓的压迫是造成脊髓损伤的重要机制;脊髓髓内信号的改变常常提示脊髓功能恢复不良.     

The computed tomography-based fractal analysis of trabecular bone structure may help in detecting decreased quality of bone before urgent spinal procedures

Background Context

To date, no reliable method is available to determine the parameters of bone density based on the routine spinal computed tomography (CT) in the emergency setup. We propose the use of fractal analysis to detect patients with poor quality of bone before urgent or semi-urgent spinal procedures.

颅底凹陷症合并寰枢椎脱位的手术治疗进展

<正>颅底凹陷症（basilar invagination,BI）合并寰枢椎脱位（atlantoaxial dislocation,AAD）是一类由先天性或继发性因素导致的复杂颅颈交界区病变。由于患者齿状突向上和向后移位,压迫邻近的延髓和脊髓,引起一系列神经症状。传统的经口齿状突切除能够直接解除压迫,但是会导致颅颈区稳定性进一步破坏,远期效果并不理想。     

颅底凹陷症的分型及治疗进展

颅底凹陷症是一种以颅颈交界区复杂骨结构畸形为基础的神经脊髓压迫综合征,其发病机制多与胚胎发育过程形成的扁平颅底、枕颈融合、Kleip-Feil畸形等有关[1],也可能与寰枢椎失稳后代偿有关[2],多表现为寰枢椎脱位,齿状突向后、向上陷入枕骨大孔,压迫脑干或延髓,引起颈部疼痛,四肢乏力、感觉麻木等神经症状。对其发生机制、分型的了解,有助于外科治疗策略的选择,笔者就近年来颅底凹陷症的分型和治疗进展作一综述。     

Chinese Journal of Traumatology won the financial aid from ＂Global Influ- ence Promotion Project for Chinese Scientific and Technical Journals＂

Objective： To determine the frequency of adrenal injuries in patients presenting with blunt abdomi- nal trauma by computed tomography （CT）. Methods： During a 6 month period from January 1, 2011 to June 30, 2011, 82 emergency CT examinations were performed in the setting of major abdominal trauma and ret- rospectively reviewed for adrenal gland injuries. Results： A total of 7 patients were identified as having adrenal gland injuries （6 males and 1 female）. Two patients had isolated adrenal gland injuries. In the other 5 patients with nonisolated injuries, injuries to the liver （1 case）, spleen （1 case）, retroperitoneum （2 cases） and mesentery （4 cases） were identified. Overall 24 cases with liver injuries （29 %）, 11cases with splenic injuries （13%）, 54 cases with mesenteric injuries （65%）, 14 cases （17%） with retroperitoneal injuries and 9 cases with renal injuries were identified. Conclusion： Adrenal gland injury is identified in 7 patients （11.7%） out of a total of 82 patients who underwent CT after major abdominal trauma. Most of these cases were nonisolated injuries. Our experience indicates that adrenal injury resulting from trauma is more common than suggested by other reports. The rise in incidence of adrenal injuries could be attributed to the mode of injury.     

颅底凹陷症患者枕颈融合术后枕颈角的变化及临床意义

【摘要】 目的：观察颅底凹陷症（basilar invagination,BI）患者枕颈融合（occipito-cervical fusion,OCF）术后枕颈角（occipito-C2 angle,OC2A）的变化,分析术后OC2A变化值与OC2A术中矫正值的相关性以及对术后下颈椎的影响。方法：回顾性分析2013年9月～2019年4月我院收治的行OCF手术治疗的30例原发性BI患者的临床资料。其中男11例,女19例,年龄49.0±12.2岁（29~71岁）。固定节段：C0-C2 20例,C0-C3 8例,C0-C4 2例。在患者术前和术后7d、3个月、6个月、1年、2年时的标准颈椎侧位X线片上测量OC2A,在术后7d和术后2年时测量下颈椎椎间盘与椎体高度比（S值）、下颈椎前凸角（C2-C7角）、C4椎体中心至McGregor线垂直距离（the occiput-C4 distance,OC4D）、寰齿前间隙（atlas-dens interval,ADI）以及斜坡椎管角（clivus-canal angle,CCA）。计算术后7d与术前OC2A的差值,记为OC2A术中矫正值;计算术后2年与术后7d OC2A、S值、C2-C7角、OC4D、ADI、CCA的差值,分别记为OC2A术后丢失值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA。Pearson相关分析法研究OC2A术后丢失值与OC2A术中矫正值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA 之间的相关性。结果：患者术前OC2A为5.4°±7.2°,术后7d、3个月、6个月、1年、2年OC2A分别为15.8°±5.6°、13.5°±4.5°、12.4°±4.7°、11.6°±4.6°、11.2°±5.1°,术后1年与2年随访OC2A值比较差异无统计学意义（P>0.05）,其余各随访时间点OC2A两两比较差异均有统计学意义（P<0.05）。术后7d和2年的S值为0.469±0.034、0.436±0.042,C2-C7角为16.5°±8.4°、10.9°±6.7°,OC4D为6.14±0.63cm、5.31±0.55cm,ADI为2.37±0.85mm、3.18±0.92mm,CCA为141.4°±21.1°、132.6°±17.5°,术后2年均较术后7d减小,差异有统计学意义（P<0.05）。OC2A术中矫正值为10.4°±9.9°,OC2A术后丢失值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA分别为4.6°±4.2°、-0.033±0.018、-5.6°±5.2°、-0.83±0.48cm、-0.81±0.67mm、-8.8°±18.4°。Pearson相关分析提示OC2A术后丢失值和术中矫正值呈强负相关（r=-0.699,P<0.001）,与ΔC2-C7角、ΔS值、ΔOC4D、ΔADI、ΔCCA 均呈正相关（r=0.429,r=0.413,r=0.347,r=0.296,r=0.675;P＜0.05）。结论：BI 患者术中OC2A矫正值越大,术后OC2A丢失越多,术后1年OC2A丢失趋于稳定;且OC2A丢失过多易造成下颈椎曲度发生显著改变。     

颅底凹陷症伴寰枢椎脱位患者的寰枢椎侧块关节影像学分型

目的:分析颅底凹陷症伴寰枢椎脱位患者颅颈交界区三维CT影像学特征,提出寰枢椎侧块关节分型,探讨其对手术决策的意义。方法:回顾分析我院2010年6月～2018年6月收治的颅底凹陷症患者,纳入115例作为观察组,其中男24例,女91例,年龄12～74岁(46.7±8.9岁)。选择年龄、性别相匹配且不伴枕颈区病变的30例作为对照组,其中男6例,女24例,年龄14～76岁(45.8±9.4岁)。观察分析两组患者枕颈区三维CT影像学资料,测量对比两组患者三维CT中寰枢椎侧块关节在冠状面、矢状面上的倾斜角。将观察组侧块关节在冠、矢状面倾角作为寰枢椎侧块关节分型依据,侧块关节滑脱及侧块关节融合作为分型修正指标,制定侧块关节分型。观察组中寰枢椎侧块关节冠状面倾角在对照组95%置信区间(confidence interval,CI)上限外,则视为冠状面倾斜;矢状面倾斜角在对照组95%CI外,则视为矢状面倾斜。根据侧块关节冠、矢状面倾斜分型:观察组中双侧侧块关节均无冠状面、矢状面倾斜,则为Ⅰ型;单侧或双侧侧块关节矢状面倾斜,无冠状面倾斜,则为Ⅱ型;单侧或双侧侧块关节冠状面倾斜,无矢状面倾斜,则为Ⅲ型;单侧或双侧侧块关节同时存在冠、矢状面倾斜,或者双侧侧块关节分别为冠状面倾斜和矢状面倾斜,则为Ⅳ型。根据侧块关节融合与滑脱情况进行分型修正:不伴侧块关节融合F0,侧块关节前缘或后缘小面积量骨性融合为F1,侧块关节大面融合为F2;不伴滑脱为D0,伴冠、矢状面部分滑脱为D1,完全滑脱或伴侧块关节绞锁为D2。通过术中全麻下颅骨牵引评估观察组患者复位难易,统计不可复型患者在侧块关节各分型中的分布情况,分析分型与复位难易相关性。结果:对照组30例中60侧侧块关节冠、矢状面倾角分别为25.4°±4.1°和2.4°±5.8°。观察组冠状面倾斜角95%CI为17.2°～33.6°,矢状面倾斜角95%CI为-9.2°～14.0°。观察组115例患者寰枢椎侧块关节分型:Ⅰ型22例(19.1%),Ⅱ型59例(51.3%),Ⅲ型8例(7.0%),Ⅳ型26例(22.6%)。Ⅰ型中伴D1患者7例,伴F1、F2、D2 0例;Ⅱ型中伴F11例,F2 2例,D1 42例,D2 2例;Ⅲ型中伴F1 1例,D1 5例,伴F2、D2 0例;Ⅳ型中伴F1 1例,F2 1例,D118例,D2 3例。Ⅰ型2 2例中不可复型患者2例(9.1%),Ⅱ型23例(39.0%),Ⅲ型3例(37.5%),Ⅳ型12例(46.2%)。观察组115例患者牵引下评估为不可复型40例。Ⅰ型不可复型患者占比显著低于Ⅱ与Ⅳ型患者,具有统计学差异(P0.05)。伴F1、F2及D2共11例均为不可复型。伴D1患者中不可复型患者占比显著高于D0,具有统计学差异(P0.05)。结论:根据颅底凹陷症伴寰枢椎脱位患者寰枢椎侧块关节的三维CT影像学特征提出寰枢椎侧块关节分型,有助于术前评估颅底凹陷症复位难易,对伴寰枢椎脱位的颅底凹陷症患者的手术决策具有重要指导作用。     

前后路联合手术治疗颅底陷入症合并小脑扁桃体下疝畸形

目的：探讨颅底陷入症合并小脑扁桃体下疝畸形的手术治疗方法及效果。方法：8例颅底陷入症合并小脑扁桃体下疝畸形患者，术前均有不同程度四肢痉挛性瘫痪及感觉障碍，均行CT、MRI检查并测量有关数值：Klaus高度指数、齿状突尖到脑桥延髓交界处的距离及小脑扁桃体下疝深度。所有患者均首先接受后路减压、枕颈钛板固定、植骨融合，然后再经口咽行齿状突磨除术。结果：术后症状均得到缓解，随访8个月至2年，平均1．5年，术后半年8例患者生活均能自理，术后1年，4例患者能参与一般的体育活动，另4例患者也能进行较轻的劳动。MRI示内固定稳固，延颈髓角度明显增大，脊髓压迫解除，植骨融合。结论：对颅底陷入症合并小脑扁桃体下疝畸形的患者先行后路减压固定、植骨融合，再行前路经口咽人路磨除齿状突的联合手术，安全可靠、效果好。     

Method of computed tomography-based stereotactic biopsy with arteriographic control

A method for computed tomography (CT)-based stereotactic biopsy of intracranial neoplasms with arteriographic control is described. Stereotactic CT and digitized stereotactic arteriographic data are input to a three-dimensional computer matrix that corresponds to the coordinate system of a stereotactic frame located in the operating room. A site for biopsy is selected by cursor from the CT display screen. The computer calculates and outputs the mechanical adjustments of the stereotactic frame necessary to place the target point into the focal point of the frame. Horizontal and vertical approach angles are determined from the digitized arteriogram and are displayed as settings on the stereotactic frame that represent an avascular trajectory along which the lesion may be biopsied safely. This procedure has been used successfully in 86 patients, with no morbidity or mortality.     

Ideal entry point and trajectory for C2 pedicle screw placement in basilar invagination patients with high-riding vertebral artery based on 3D computed tomography

BACKGROUNDC2 pedicle screw placement in patients with basilar invagination (BI) is fraught with risks because of a high incidence of anatomical variations and high-riding vertebral artery (HRVA). However, no study can be found in the literature that attempted to identify the ideal entry point and trajectory through the C2 pedicle in BI patients with HRVA.PURPOSETo investigate the parameters of ideal entry point and trajectory for C2 pedicle screw placement in BI patients with HRVA and compare them with those in BI patients without HRVA and patients without BI as control. These parameters would serve as a guide to pedicle screw placement.STUDY DESIGNA retrospective comparative study.PATIENT SAMPLEA total of 396 patients (198 consecutive BI patients and 198 matched patients without BI as control) and 792 unilateral pedicles from April 2017 to October 2021 at two medical centers were included.OUTCOME MEASURESThe insertion parameters of mediolateral angle, surface distance, cephalad angle, and vertical distance from the superior border of the lamina were the primary outcome measures for the reference of C2 pedicle screw placement. Furthermore, factors that affect the primary insertion parameters were assessed via multiple linear regression analyses.METHODAccording to the diagnosis of BI and HRVA, the unilateral pedicles were assigned into HRVA of BI, non-HRVA of BI, HRVA of control, and non-HRVA of control groups. Subgroup analyses based on Goel types A and B were also performed. Moreover, vertebral artery (VA) anomalies that might result in potentially serious complications were identified and systematically compared.RESULTSThe measurements of insertion parameters in BI patients with HRVA indicated a mean mediolateral angle of 27.42°, a mean cephalad angle of 43.02°, a mean surface distance of 9.74 mm, and a mean vertical distance from the superior border of the lamina of 3.85 mm. Compared with that in BI patients without HRVA, the measurements suggested that the entry point in BI patients with HRVA should be shifted upward by 0.38 mm and the trajectory should be angled cephalad by 6.05° and medially by 4.78°. In the control group, changes in the insertion parameters between HRVA and non-HRVA showed a similar trend to the BI group. Multiple linear regression showed that mediolateral angle was significantly associated with the male gender (B=?0.930, p=.017) and the diagnoses of HRVA (B=6.964, p<.001), Goel type A (B=?1.656, p=.003), and Goel type B (B=0.981, p=.030). Moreover, cephalad angle was significantly associated with the length of lateral mass (B=?0.319, p=.001) and the diagnoses of HRVA (B=3.254, p<.001) and Goel type A (B=6.924, p<.001). The VA anomalies were significantly higher in the BI group than in the control group.CONCLUSIONSThe insertion parameters of the ideal entry point and trajectory for C2 screw placement in BI patients with HRVA were remarkably different from those of non-HRVA of BI, HRVA of control, and non-HRVA of control cohorts. Preoperative 3D computed tomography (CT) and CT angiography are highly recommended in such patients to improve intraoperative safety and reduce postoperative complications.     

颅底凹陷症合并寰枢椎脱位患者枕颈角与下颈椎曲度的关系

目的:评估颅底凹陷症(basilar invagination,BI)合并寰枢椎脱位(atlantoaxial dislocation,AAD)患者枕颈角(O-C2角)与下颈椎曲度(C2-7 Cobb角)之间的关系。方法:回顾性分析2009年1月~2013年6月21例于我院因BI合并AAD行后路复位枕颈融合术患者的临床资料。21例患者中男12例,女9例;年龄21~65岁(41.6±10.7岁);病程4个月~18年(4.3±3.9年)。于手术前和术后末次随访时在颈椎中立位侧位X线片上测量O-C2及C2-7 Cobb角(C2-7角),并计算O-C2角及C2-7角的变化量dO-C2角和dC2-7角,前凸为“+”值,后凸为值。根据O-C2角的大小,将21例患者术前和末次随访时分为10°≤O-C2角≤20°组、O-C2角10°组及O-C2角20°组。观测手术前后不同O-C2角组C2-7角的差异,分析手术前后O-C2角与C2-7角的相关性。结果:21例患者中,12例患者固定节段为C0-C3,9例患者为C0-C4。随访时间为10~32个月(18.3±6.6个月)。术后末次随访时O-C2角较术前平均增大6.3°,C2-7角较术前平均减小6°,手术前后两指标比较均存在显著性差异(P0.05)。术前6例(28.6%)患者O-C2角在10°~20°间,12例(57.1%)10°,3例(14.3%)20°。OC2角10°组C2-7角显著大于O-C2角10°~20°组及20°组(P0.05),O-C2角10°~20°组与20°组比较无显著性差异(P0.05)。末次随访时10例(47.6%)患者O-C2角在10°~20°间,4例(19.0%)20°,7例(33.4%)10°,O-C2角20°组C2-7角显著小于O-C2角10°~20°组及10°组(P0.05),O-C2角10°~20°组与10°组比较无显著性差异(P0.05)。术前及术后末次随访时O-C2角与C2-7角均存在显著性负相关(术前r=-0.732,P0.05;术后r=-0.603,P0.05);d0-C2角及dC2-7角亦存在显著性负相关(r=-0.721,P0.05)。结论:BI合并AAD患者枕颈角与下颈椎曲度关系密切,行后路复位枕颈融合术时需监测枕颈角的固定角度,若枕颈角过大有可能导致术后下颈椎曲度出现代偿性减小。     

Surgical outcomes of posterior occipito-cervical decompression and fusion for basilar invagination: A prospective study

Study designA Prospective Study.ObjectiveTo assess results of posterior occipito-cervical decompression and fusion operated with intra-operative traction/manipulation and instrumented reduction in cases of Basilar Invagination(BI).MethodsTotal 22 patients of 8–65 years with diagnosed BI were operated for posterior occipito-cervical fusion by intra-operative traction/manipulation and instrumented reduction. Fusion was done using autologous bone graft taken from iliac crest. Immediate post-operative, first month and then every 3 months’ follow-up examination were done for minimum period of 2 years.Results22 patients (10 males,12 females) with mean age of 23.9 years having BI were included. 11 patients had C1 occipitalization, 4 had platybasia and 9 had atlanto-axial dislocation (AAD). 1 patient with os odontoideum with kyphotic deformity expired on 4th postoperative day due to respiratory insufficiency (mortality rate 4.54%). Neurological improvement by at least by one grade according to RANAWAT’s and/or NURICK’S scale was observed in 17/21 patients (80.95%). 3 patients remained static and 1 had neuro-worsening. Mean mJOA score of 13.14 improved to 16.24. All had reduction of dens below foramen magnum according to McRae, chamberlain line and Ranawat index. Bone graft fused in all patients as confirmed with CT scan and dynamic X-rays. 1 wound dehiscence and 1 asymptomatic implant loosening were seen on follow-up.ConclusionSurgical treatment of BI with intra-operative traction/manipulation, instrumented reduction and posterior occipito-cervical fusion can achieve good correction of radiology, functional performance and clinical neurology as well as excellent fusion rates without adverse effects of trans-oral surgery.