Role of transarticular screw fixation in tuberculous atlanto-axial instability

Prospective study of 27 consecutive cases of tuberculous atlanto-axial instability operated between 1998 and 2003. Early surgical stabilization of tuberculous atlanto-axial instability has gained popularity. This is largely due to success of chemotherapy in rapid control of infection. Although selective atlanto–axial fusion techniques are advocated in other indications, their role in tuberculosis remains confined to atlanto-axial wiring techniques that are mechanically unsound. The role of three-point rigid fixation using trans-articular screws (TAS) remains unclear. The objectives of this study are: (1) To define the role of trans-articular screws in tuberculous atlanto-axial instability based on radiological criteria. (2) To attempt to separate patients that can be treated by selective atlanto-axial fixation as against the standard occipito–cervical fusion (OCF). (3) Compare the clinical and radiological outcome parameters between the two groups. Twenty-seven consecutive patients of tuberculous atlanto-axial instability were operated between 1998 and 2003. The pattern of articular surface destruction and the reducibility of the atlanto-axial complex were assessed on plain radiographs and MRI. The reducibility of the C1–C2 joint was graded as reducible, partially reducible and irreducible. Pattern of the C1–C2 articular mass destruction was grouped as minimal, moderate and severe. The patients were divided into two surgical groups based on radiological findings and were treated with TAS (n=11) and OCF (n=16) fusion. The three-point fixation provided by the TAS allowed early brace free mobilization by 3 months with fusion rate of 100%. Fusion occurred in 83.16% in the OCF group. Implant failure occurred in two patients who underwent OCF. The patient satisfaction rate in the TAS group and the OCF group was 90.90 and 62.50%, respectively. Results in 27 consecutive patients demonstrate improved patient fusion and satisfaction rates in the TAS group. Judicious selection of patients for TAS fixation is possible with relatively few complications in tuberculosis of the atlanto-axial complex. This, however, requires a thorough understanding of the MRI pattern of involvement of the atlanto-axial complex that is difficult in non-endemic areas.     

应用经关节螺钉固定在寰枢关节不稳中的生物力学研究与临床应用

目的 探讨后路经关节螺钉固定(Magerl技术)加植骨融合治疗寰枢关节不稳定的生物力学特性及其临床价值.方法 生物力学研究:取新鲜冰冻尸体标本30具,随机分成5组:完整标本组、寰枢椎不稳实验模型组、寰枢椎后路椎弓根螺钉固定组、寰枢椎经关节螺钉固定组及寰枢椎经关节螺钉联合Brooks钢丝固定组,每组各6具.标本施加±1.5N·m纯力偶矩作为加载的最大力矩,模仿前屈、后伸,左、右侧弯,左、右轴向旋转6种生理性运动,测量各种生理性运动的活动范围(ROM)和中性区(NZ)值.应用SPSS 11.0软件进行统计分析,比较组间差异.临床研究:2000年2月至2005年1月应用寰枢椎经关节螺钉(Magerl技术)固定、C1.2棘突间植骨融合术治疗寰枢椎不稳患者23例,男16例,女7例;年龄17～62岁,平均38.6岁;先天性畸形致脱位3例,外伤性脱位20例.所有患者进行定期随访和影像学检查,评估颈椎稳定性和植骨融合率.结果 标本生物力学测试结果表明:屈伸稳定性、侧弯稳定性和轴向稳定性均为寰枢椎经关节螺钉联合Brooks钢丝固定组＞寰枢椎经关节螺钉固定组＞寰枢椎椎弓根螺钉固定组＞寰枢椎完整标本组＞寰枢椎不稳模型组,组间差异有统计学意义.临床研究表明:23例共放置经关节螺钉46枚;无一例发生椎动脉损伤、脊髓损伤或舌下神经麻痹等并发症.23例患者均获随访,随访时间4～36个月,平均15个月;随访中2例患者主诉旋转活动部分受限;影像学检查提示所有患者植骨全部融合.结论 单纯的Magerl螺钉固定失稳的寰枢关节具有足够坚固的生物力学性能,临床上结合棘突间植骨可达到满意的骨性融合.     

寰枢椎脱位或不稳患者手术治疗前后椎动脉血流的变化

目的：观察寰枢椎脱位或不稳定患者手术前后椎动脉血流情况。方法：利用彩色超声多谱勒，术前检查15例寰枢椎脱位和8例不稳定患者椎动脉的最大血流速度(心脏收缩期血流速度)、最小血流速度(心脏舒张期血流速度)和血管阻力指数，根据同一椎动脉下颈段和上颈段的血流速度和血管阻力的差别判断上颈段椎动脉的血流是否异常。所有患苦手术复位和内固定后做同样的俭查。结果：15例寰枢椎脱位患者中椎动脉血流术前18侧异常．11侧正常．1侧椎动脉未发育．术后18侧异常者16侧恢复正常，1侧明显改善，1侧无变化；3侧南术前正常变为异常。8例寰枢椎不稳定患者中椎动脉术前12侧异常，4侧正常。术后5侧恢复正常，仍为异常者7侧，但3侧明显改善：1侧由术前正常变为异常。结论：寰枢椎脱位或不稳定患者的椎动脉血流夫多数发生异常．手术复位内固定后大多数能够获得改善。     

Computer-assisted screw insertion for cervical disorders in rheumatoid arthritis

To reconstruct highly destructed unstable rheumatoid arthritis (RA) cervical lesions, the authors have been using C1/2 transarticular and cervical pedicle screw fixations. Pedicle screw fixation and C1/2 transarticular screw fixation are biomechanically superior to other fixation techniques for RA patients. However, due to severe spinal deformity and small anatomical size of the vertebra, including the lateral mass and pedicle, in the most RA cervical lesions, these screw fixation procedures are technically demanding and pose the potential risk of neurovascular injuries. The purpose of this study was to evaluate the accuracy and safety of cervical pedicle screw insertion to the deformed, fragile, and small RA spine lesions using computer-assisted image-guidance systems. A frameless, stereotactic image-guidance system that is CT-based, and optoelectronic was used for correct screw placement. A total of 21 patients (16 females, 5 males) with cervical disorders due to RA were surgically treated using the image-guidance system. Postoperative computerized tomography and plane X-ray was used to determine the accuracy of the screw placement. Neural and vascular complications associated with screw insertion and postoperative neural recovery were evaluated. Postoperative radiological evaluations revealed that only 1 (2.1%; C4) of 48 screws inserted into the cervical pedicle had perforated the vertebral artery canal more than 25% (critical breach). However, no neurovascular complications were observed. According to Ranawat's classification, 9 patients remained the same, and 12 patients showed improvement. Instrumentation failure, loss of reduction, or nonunion was not observed at the final follow-up (average 49.5 months; range 24-96 months). In this study, the authors demonstrated that image-guidance systems could be applied safely to the cervical lesions caused by RA. Image-guidance systems are useful tools in preoperative planning and in transarticular or transpedicular screw placement in the cervical spine of RA patients.     

Atlanto-axial joint of atlanto-axial subluxation patients due to rheumatoid arthritis before and after surgery, morphological evaluation using CT reconstruction

This study investigated the preoperative morphology and postoperative fusion of the atlanto-axial joint (AAJ) in patients with atlanto-axial subluxation (AAS) due to rheumatoid arthritis (RA) using computed tomography (CT). Furthermore, we examined the relationship between the preoperative morphology of AAJ and other radiographic results. Thirty patients with AAS due to RA treated by C1–2 transarticular screw fixation (TSF) were reviewed. The morphology of the AAJ was evaluated using sagittal reconstruction views on CT before and 1 year after surgery. Thereafter, the atlanto-dental interval (ADI) value at the neutral and maximal flexion position and atlanto-axial angle (AAA) at the neutral position was assessed in preoperative lateral cervical radiographs. The preoperative morphology of the AAJ on CT reconstruction views was graded as follows: Grade 1 showed maintenance of the joint space, Grade 2 showed the joint space narrowing and Grade 3 showed the destructive abnormality of subchondral bone. After surgery, the ADI value at the neutral position was assessed in lateral cervical radiographs. Furthermore, the fusion in the AAJ was investigated using CT sagittal reconstruction views taken 1 year after surgery. The preoperative CT image of the AAJ demonstrated Grade 1 in 12 cases (Group A), Grade 2 in 9 cases (Group B) and Grade 3 in 9 cases (Group C). There was no significant difference in age, gender and duration of RA among the three groups. The average ADI value at the flexion position was 11.0 mm in Group A, 12.3 mm in Group B and 12.7 mm in Group C (p > 0.313). The average ADI value at the neutral position before surgery was 4.5 mm in Group A, 7.3 mm in Group B and 11.4 mm in Group C (p < 0.003). The mean AAA value was 20.8° in Group A, 21.8° in Group B and 8.4° in Group C (p < 0.033). The average ADI value after TSF was 1.7 mm in Group A, 2.1 mm in Group B and 3.0 mm in Group C (p > 0.144). Fusion in the AAJ 1 year after surgery was demonstrated in 14 cases (46.7%; Group A, 0 case; Group B, 5 cases; Group C, 9 cases). According to the preoperative grading of the AAJ, the postoperative fusion in the AAJ was demonstrated in 0 of 32 joints (0%) in Grade 1, 7 of 18 joints (38.9%) in Grade 2 and all of 10 joints (100%) in Grade 3. In conclusion, this study showed that a destructive abnormality of subchondral bone in the AAJ induced an enlargement of the ADI and anterior inclination of the atlas in patients with AAS due to RA. The current study also showed that fusion in the AAJ was demonstrated in 14 of 30 patients after C1/2 TSF. This was easy to recognize in AAS patients whose joint destruction extended to the subchondral bone.     

Stage-related surgery for cervical spine instability in rheumatoid arthritis

Thirty-six consecutive patients with cervical spine instability due to rheumatoid arthritis (RA) were treated surgically according to a stage-related therapeutic concept. The aim of this study was to investigate the clinical results of these procedures. The initial change in RA of the cervical spine is atlanto-axial instability (AAI) due to incompetence of the cranio-cervical junction ligaments, followed by development of a peridontoid mass of granulation tissue. This results in inflammatory involvement of, and excessive dynamic forces on, the lateral masses of C1 and C2, leading to irreducible atlanto-axial kyphosis (AAK). Finally, cranial settling (CS) accompanied by subaxial subluxation (SAS) occurs. According to these three separate pathological and radiological lesions, the patients were divided into three therapeutic groups. Group I comprised 14 patients with isolated anterior AAI, who were treated by posterior wire fusion. Group II comprised 15 patients with irreducible AAK, who were treated by transoral odontoid resection. The fixation was done using anterior plating according to Harms in combination with posterior wire fusion according to Brooks. Group III comprised seven patients with CS and additional SAS, who were treated with occipito-cervical fusion. Pre- and postoperatively, evaluation was performed using the parameters pain (visual analog scale), range of motion (ROM), subjective improvement and Health Assessment Questionnaire (HAQ). The neurologic deficit was defined according to the classification proposed by Ranawat. Radiographs including lateral flexion and extension views, and MRI scans were obtained. The average clinical and radiographic follow-up of all patients was 50.7 ± 19.3 months (range 21–96 months). No perioperative fatality occurred. Postoperative pain was significantly relieved in all groups (P < 0.001). In group II a slight improvement in the HAQ was obtained. In groups I and II the ROM of all patients increased significantly (average gain of motion in group I: 11.3°± 7.8° for rotation; 7.8°± 5.6° for bending; average gain of motion in group II: 21.5°± 14.0° for rotation; 17.2°± 5.5° for bending), while it decreased significantly in group III (10.7°± 18.1° for rotation; 6.7°± 18.5° for bending). Preoperatively 27 patients had a manifest neurologic deficit. At follow-up four patients remained unchanged, all others improved by at least one Ranawat class. All patients, except one, showed solid bony fusion. According to the significantly improved postoperative subjective self-assessment and the clinical and radiological parameters, transoral plate fixation combined with posterior wire fixation after transoral odontoid resection represents an effective reliable and safe procedure for the treatment of irreducible AAK in rheumatoid arthritis. Received: 4 March 1999 Accepted: 19 May 1999     

Bovine bone grafting in occipito-cervical fusion for atlanto-axial instability in rheumatoid arthritis

Summary Bovine bone chips (Surgibone®) were used in occipito-cervical fusion in nine patients with atlanto-axial instability due to rheumatoid arthritis. The patients were examined with CT 12–15 months after surgery.Graft resorbtion was observed in one patient. The other 8 patients showed preserved grafts, in most cases the grafts appeared to be in contact with the underlying bone. One patient was revised, and at the grafted site a bony bridge was found.In conclusion, the use of bovine chips in posterior occipitocervical fusion will not lead to predictable bone union. However, there seem to be exceptions to that rule.     

Factors affecting the interface of cervical spine facet screws placed in the technique by Roy-Camille et al.

The objective of the study was to investigate the influence of bone cement, length of burr hole and bone density on pullout force and insertional screw torque of cervical spine facet screws. Both facets of 24 human cervical vertebrae were scanned for bone mineral density (BMD) and assigned to two groups for measuring of insertional screw torque and pullout strength. Maximal insertional screw torque was measured and removal of the screws was performed in displacement control (0.25 mm/s) without bone cement (PMMA), with 0.1 ml of PMMA and with the burr hole completely filled with PMMA. Screw torque was 59.1 N cm (±25.7 N cm), pullout force was 382.8 N (±140.5 N) without PMMA. Injection of 0.1 ml PMMA did not change significantly both screw torque (p=0.73) and pullout (p=0.129). Filling of the burr holes with PMMA increased significantly both screw torque (p<0.0001) and pullout force (p=0.028) when compared with injection of 0.1 ml of PMMA. A positive, moderate correlation was seen between BMD and screw torque before (r=0.501; p=0.097) and after filling with PMMA (r=0.514; p=0.088), BMD and pullout force before (r=0.441; p=0.152) and after complete filling with PMMA (r=0.673; p=0.047). The PMMA does increase both screw torque (p<0.0001) and pullout force (p=0.028) of facet screws significantly if the burr hole is filled with PMMA completely when compared with injection of 0.1 ml PMMA. Bone mineral density of the cervical facets moderately correlates with peak insertional torque and pullout force. This is true for a facet without PMMA and for a facet filled with PMMA. The length of the burr hole seems to be less important.     

Accuracy of freehand fluoroscopy-guided placement of C1 lateral mass and C2 isthmic screws in atlanto-axial instability

Background  

The C1 lateral mass and C2 isthmic stabilization, as introduced by Goel and Laheri and by Harms and Melcher, is a well-known fixation technique. We present the clinical and radiographic results with freehand fluoroscopy guided C1 lateral mass and C2 isthmic fixation in a consecutive series of 28 patients, evaluating the accuracy of screw placement.     

传统寰枢椎后路椎弓根螺钉置钉技术和个性化导向模板辅助置钉技术的临床对比研究

【摘要】 目的：比较传统置钉技术与个性化导向模板辅助置钉技术手术治疗寰枢椎不稳症的置钉准确性。方法：回顾性分析2011年6月~2017年7月我科收治的寰枢椎不稳症患者56例（男33例,女23例）,男性年龄56.8±8.9岁（36~71岁）,女性年龄54.5±10.8岁（33~72岁）,其中30例行传统寰枢椎后路椎弓根螺钉内固定植骨融合术（对照组）,26例行个性化定点-定向导向模板辅助寰枢椎椎弓根螺钉内固定植骨融合术（观察组）。寰椎和枢椎定点导板均有长条状扶手设计。术后3d复查CT评估寰椎和枢椎螺钉置入的安全性,并将螺钉位置分为4级：0级,螺钉完全位于骨性钉道内;1级,在横断面或矢状面上,螺钉直径穿破骨皮质≤50%;2级,在横断面或矢状面上,螺钉直径穿破骨皮质＞50%;3级,螺钉直径完全穿破骨皮质。比较两组螺钉安全率（0级设为安全,1~3级设为存在风险）、手术时间、术中透视次数以及术中出血量。结果：寰椎椎弓根螺钉对照组0级48枚、1级7枚、2级2枚、3级1枚,观察组0级49枚、1级2枚、2级1枚、3级0枚,各级组间比较均无明显差异。枢椎椎弓根螺钉对照组0级53枚、1级6枚、2级1枚、3级0枚,观察组0级48枚、1级2枚、2级0枚、3级0枚,各级组间比较均无明显差异（P＞0.05）。螺钉安全率对照组及观察组组间比较存在差异（P=0.019）;平均手术时间对照组109.2±17.1min,观察组115.2±16.6min,两组间比较存在差异（P=0.009）;平均透视次数对照组12.50±1.95次,观察组6.85±2.44次,两组间比较存在差异（P＜0.0001）;平均术中出血对照组198.1±108.3ml,双导板组160.3±135.4ml,两组间比较无明显差异（P=0.216）。患者术后随访时间14~26个月（19.4±4.1个月）,所有病例行寰枢椎后路术后均获得融合。结论：改良个性化导向模板辅助寰枢椎椎弓根螺钉置钉技术比传统置钉技术更能有效减少术中X线透视次数并提高临床手术置钉的准确性。     

Sudden death from cord compression associated with atlanto-axial instability in rheumatoid arthritis. A case report

We have presented a case of death from AAS in a rheumatoid patient. We believe her cardiac arrest was caused by an acute myocardial infarction (MI) or dysrhythmia. We cannot determine whether the MI/dysrhythmia was itself a lethal event. The damage to her lower medulla and upper cervical cord, which most likely occurred at the time of her intubation, was a lethal injury. The presence of spinal cord ischemic changes and acute inflammatory cells within the cord indicate that the cervical spine injury occurred premortem. This patient had no neck pain, no neurologic symptoms or signs, and had AAS of 8 mm. Weissman suggests that 9 mm of AAS is the critical amount. The 1-mm subluxation difference here is probably not significant, because there is inherent error when measuring radiographs. We took into account her clinical and radiographic data, and decided to manage her C1-C2 articulation nonoperatively. Nevertheless, her atlanto-axial joint consisted of abnormal soft and hard tissue. This joint was satisfactory for her usual activities of daily living. The anteroposterior forces generated during ACLS intubation, which are unlikely to disrupt a normal atlanto-axial joint, were sufficient to subluxate her joint. This case demonstrates that it behooves us to maintain a high level of awareness for potential cervical spine problems in all rheumatoid arthritis patients.     

下颈椎经关节螺钉导向配套器械的设计与运用

目的：设计并运用下颈椎经关节螺钉导向配套器械,为临床提供帮助。方法：设计生产下颈椎经关节螺钉导向配套装置,运用2具带有头颅的颈椎标本检验,并应用于17例临床患者,植入下颈椎经关节螺钉68枚。结果：应用下颈椎经关节螺钉导向配套装置植入下颈椎经关节螺钉顺利,解剖后发现螺钉位置好,无关节突劈裂等,患者植入后经3-12个月随访,无神经受累症状,未发现螺钉松动。结论：运用下颈椎经关节螺钉导向配套器械植入下颈椎经关节螺钉,方便实用,有临床推广价值。     

计算机辅助颈椎椎弓根螺钉置入参数的获取

目的探讨利用CT三维重建技术模拟颈椎椎弓根螺钉置入的方法,以获得预置螺钉的椎弓根三维定量解剖数据及置钉参数。方法将颈椎16排CT扫描的数据导入Mimics8．1软件中,进行颈椎CT三维重建,在三维图像上构建一圆柱体来模拟椎弓根螺钉,并置入颈椎椎弓根内,然后测量各项置钉参数。结果应用CT三维重建技术可以获得清晰的颈椎三维图像,使用软件测量功能可精确地获取预置螺钉的椎弓根解剖数据（椎弓根宽度和轴线长度）和置钉参数（置钉的α角、β角以及置钉α角安全范围）。结论通过CT三维重建技术获取椎弓根螺钉置入个体化三维数据,为术中实施颈椎椎弓根螺钉置入提供依据,是颈椎椎弓根螺钉置入安全性研究的一种可靠方法。     

Surgical management of the subaxial cervical spine (C3-T1) in rheumatoid arthritis

Summary In the process of skeletal changes in rheumatoid arthritis (RA) the lower cervical spine may characteristically be affected by subluxation, discoligamentous insufficiency and bone resorption. These may cause severe pain and important neurological deficit and necessitate surgical intervention. Out of a series of 122 RA patients who underwent surgery of the cervical spine, in 23 the subaxial cervical spine was operated on. Pain was the leading symptom in all patients. In only six were there no pathological neurological findings, and all showed marked kyphotic deformity of the cervical spine. Fourteen patients were operated by a posterior approach, one by a ventral approach, and in eight patients the surgical procedure consisted of anterior decompression and dorsal stabilization. A mean of 21.3 months after surgery, clinical and radiological evaluation was performed. In two patients the sensomotor deficit improved, and out of 16 patients with cervical myelopathy, nine improved. No pseudoarthrosis was noted, and moderate loss of correction was seen in only three patients. In a subjective evaluation, 14 patients rated their result as good, six as fair and none as poor. In conclusion, following decompression, we noted good recovery from myelopathic symptoms. Sufficient stability in patients with RA is achieved by a combined anterior and posterior approach, the main goal of the anterior approach being decompression by vertebrectomy and that of the posterior approach stabilization by plate and screw fixation.     

Posterior atlanto-axial fusion with the Olerud Cervical Fixation System for odontoid fractures and C1-C2 instability in rheumatoid arthritis

In posterior C1-C2 fusion, traditional wire fixation gives poor stability. The bone quality is often insufficient to provide the competent structural bone graft that is required, and the introduction of sublaminar wires is somewhat dangerous. The stability is markedly improved by adding transarticular screws, but the drawbacks of structural bone graft and sublaminar wires remain. The C1 claw of the Olerud Cervical Fixation System improves C1-C2 fixation without relying on structural bone graft or compromising the spinal canal. The aim of this study was to evaluate radiological healing and possible complications in a consecutive series of C1-C2 fusions from our department operated with the C1 claw device. Twenty-six patients (14 women) with a mean age of 73 (range 37-93) years were included. The diagnoses were odontoid fracture in 18 patients, rheumatoid instability in 6, and odontoid non-union and os odontoideum in 1 each. The patients were followed clinically and with plain radiographs for an average of 15 (range 3-27) months. There were no neurological or vascular complications, and no secondary displacements or reoperations in the series. Twenty patients followed for 6-27 months were radiographically healed. Six patients died from unrelated causes 1-38 months postoperatively. Three of these patients had no radiographs later than the postoperative control, one had a healed odontoid fracture but resorbed bone graft at 8 months, while the remaining two patients were not healed, but showed no signs of healing disturbance at the time of death. On the basis of the findings of this study, posterior C1-C2 fusion with the Olerud Cervical Fixation System seems promising. No serious complications related to the surgical procedure were encountered. The stability of the implant obviates the use of a solid bone block as a graft and still allows a high frequency of fusion healing.     

人工颈椎间盘置换的疗效及其对相邻非责任节段失稳的影响

目的:观察相邻非责任节段失稳颈椎病患者Bryan人工颈椎间盘置换术后的临床疗效及失稳节段的影像学变化。方法:2005年7月～2009年1月在我院行Bryan人工颈椎间盘置换术且术后随访36个月以上的43例颈椎病患者中,9例术前存在置换相邻节段失稳,男4例,女5例;年龄26～43岁,平均33.5岁。术前JOA评分为7～13(10.16±3.17)分,颈痛VAS为1～7(4.3±2.7)分。术前均经颈椎正侧位与屈伸动力位X线片及颈椎MRI证实存在手术相邻节段影像学失稳,但为非责任节段。C4/5置换、C5/6失稳1例;C5/6置换4例,其中C4/5失稳3例,C6/7失稳1例;C6/7置换、C5/6失稳2例;双节段置换2例:C4/5、C5/6与C5/6、C6/7各1例,均为头端相邻节段失稳。术后1周及术后3、6、12、24、36个月行JOA评分、颈痛VAS评分及Odom评分评估手术临床疗效;术前及术后3、6、12、24、36个月在颈椎动力位X线片上测量置换节段、失稳节段、颈椎整体活动度(C2～C7)及颈椎曲度。结果:术后1周JOA评分、颈痛VAS评分与术前比较无统计学差异(P>0.05),术后3、6、12、24、36个月JOA评分、颈痛VAS评分较术前明显改善,差异有统计学意义(P<0.05)。术后1周和3个月时Odom评分均为优6例、良1例、可2例,优良率为77.8%;术后6个月优6例、良2例、可1例,优良率为88.9%;术后12、24及36个月,Odom评分均为优7例、良1例、可1例,优良率为88.9%。术后3、6、12个月置换节段、失稳节段的活动度和颈椎曲度与术前比较差异无统计学意义(P>0.05);术后24、36个月,失稳节段的活动度较术前明显减小(P<0.05),置换节段活动度及颈椎曲度较术前明显增大(P<0.05);术后各时间点C2～C7活动度较术前无统计学差异(P>0.05)。随访期间未发现假体松动、移位及下沉。结论:Bryan人工颈椎间盘置换治疗颈椎病的短中期临床疗效良好,能逐渐改善年轻颈椎病患者置换相邻节段的影像学失稳。     

数字骨科技术在寰枢椎个体化置钉手术中的应用

目的 探讨数字骨科技术在寰枢椎椎弓根螺钉个性化置钉的应用价值.方法 将术前接受薄层CT扫描的30例上颈椎疾患患者(其中男16例,女14例)的数据输入Mimic和 Simpleware软件后,建立三维仿真模型,并设计最佳的椎弓根钉道,然后根据钉道设计导航模版.用激光快速成型机打印导航模版,用于手术时辅助寰枢椎椎弓根螺钉...     

经后路寰枢椎椎弓根螺钉侧块固定治疗寰枢不稳或脱位疗效观察

目的 评价后路寰枢椎椎弓根螺钉侧块固定治疗寰枢不稳或脱位的临床疗效.方法 2005年5月至2008年1月,共收治各种原因引起的寰枢椎不稳或脱位患者31例,其中男性23例,女性8例;年龄17～67岁,平均43.5岁.寰枢椎不稳或脱位原因有:齿状突陈旧性骨折17例,游离齿状突8例,齿状突骨折4例,横韧带断裂1例,类风湿关节炎1例.31例患者均有枕颈痛表现,28例有颈椎活动受限,19例有不同程度颈髓受压症状和体征.所有病例均行后路寰枢椎椎弓根螺钉复位固定.记录患者手术时间、失血量和并发症发生情况;同时对手术前后有关临床疗效指标和影像学资料进行对比评价及统计学分析.结果 31例患者平均手术时间2.5 h,平均出血量300 ml.术后均获随访,随访时间6～37个月,平均13个月.1例患者术后出现切口感染,通过调整抗菌素和切口换药2周后得到控制;1例患者术后第5天出现肺动脉栓塞(经肺动脉造影证实),经抗凝等治疗2个月后康复.术中无椎动脉损伤,术后无C_2神经分布区疼痛或麻木病例.31例患者术前存在的枕颈部疼痛均减轻.19例颈脊髓损伤症患者末次随访脊髓功能JOA评分与术前相比明显提高(P<0.01).31例末次随访动态X线片未见寰枢椎移位,无内固定物断裂或松动;CT三维重建有2例患者寰枢椎后弓间骨小梁连续性中断.总融合率达93.6%.结论 后路寰枢椎椎弓根螺钉侧块固定具有直视下置钉、术中复位、良好的三维短节段固定等优势,是良好的寰枢椎后路固定融合技术.