Ⅰ期前后路联合手术治疗游离齿突继发的难复性寰枢椎脱位

目的探讨颈高位咽后入路前路松解、Ⅰ期后路融合治疗游离齿突继发的难复性寰枢椎脱位的临床效果。方法本组19例均为游离齿突继发的难复性寰枢椎脱位,X线片动态位不能自行复位,且术前颅骨牵引均未获得满意复位。采用颈高位咽后入路显露C1～C3,行寰枢椎前方松解复位,Ⅰ期后路寰枢融合内固定。结果 19例患者采用颈高位前方咽后入路均成功显露C1前弓～C3椎体,前路松解后复位良好,Ⅰ期行后路寰枢融合内固定,全组无一例出现脊髓损伤加重、咽喉部阻塞或窒息。1例颈后部伤口积液感染,经换药引流后痊愈;2例出现舌下神经牵拉症状,1例出现面神经刺激症状,均在1个月后恢复正常。脊髓功能正常者无神经功能损害,不全瘫患者神经功能均有部分恢复。随访植骨均获骨性融合,无内固定松脱。结论颈高位咽后入路行前方松解能够复位游离齿突继发的难复性寰枢椎脱位患者,Ⅰ期后路寰枢融合可获良好的植骨融合。     

Transarticular atlanto-axial screw fixation for treatment of C1-C2 instability

Posterior transarticular screw fixation of the C1-C2 complex has become an accepted method of arthrodesis for patients requiring posterior C1-C2 fusion. Since 2000, four patients (2 males and 2 females) were treated with this surgical approach for management of atlantoaxial instability, including odontoid fracture with unilateral C1-C2 luxation, odontoid pseudarthrosis, complex congenital malformation of the craniovertebral junction and rheumatoid arthritis. All patients underwent stabilization with 2 transarticular C1-C2 screws, without any posterior interspinous graft. Patients were maintained in a rigid cervical orthesis 3 months postoperatively. Results were good, without any complication, after a short mean follow-up (8 months). Technical aspects of the technique are reported, The risk of screw malpositioning and vertebral artery or neural injury is minimal and can be lowered by using preoperative CT scan and MRI, and by using intraoperative fluoroscopy. Transarticular C1-C2 screw fixation proves to be a major surgical approach for treatment of atlantoaxial instability.     

寰枢椎脱位翻修手术的临床疗效观察

目的 :探讨一期前路经口咽松解并后路复位固定融合术对寰枢椎脱位手术治疗失败病例翻修的手术要点及疗效。方法:2001年10月~2011年10月对29例寰枢椎脱位手术治疗失败病例行翻修手术,其中26例获得随访,男12例,女14例。初次手术时年龄4~56岁,平均33.5岁,齿状突骨折不愈合6例,齿状突发育畸形6例,横韧带断裂2例,先天性寰枕融合12例。翻修手术时年龄12~60岁,平均37.2岁。两次手术相隔11~158个月,平均44.2个月。8例初次手术后未复位,18例复位后因内固定失败再次脱位,脑干脊髓角平均101.8°。患者均有枕颈部持续性疼痛,其中19例伴脊髓神经功能障碍,JOA评分平均8.5分。均行一期前路经口咽松解、后路复位减压、寰枢椎或枕颈固定融合术,其中12例行C1-C2融合,6例C0-C2融合,3例C0-C3融合,3例C0-C4融合,2例C1-C4融合。随访患者临床疗效并进行影像学评估。结果:手术均顺利完成,手术时间210~340min,平均290min;失血量500~1100ml,平均700ml。术中未发生血管、神经和脊髓等损伤,术后无咽壁和椎管内感染发生。19例(73.1%)获得完全复位,7例不完全复位;脑干脊髓角恢复至平均143.0°,其中11例达到正常,15例小于正常。随访18～90个月,平均45个月,随访期间未见内固定松动表现,植骨均获得骨性融合;临床症状明显改善,19例伴有脊髓神经功能障碍患者末次随访时JOA评分平均12.6分。按Macnab疗效评估标准评定:优10例,良6例,无改善3例。结论:一期前路经口咽松解、后路复位减压、寰枢或枕颈固定融合术是一种具有较好临床疗效的寰枢椎脱位翻修术式。     

不稳定性Hangman骨折手术入路选择

目的:探讨前路或后路手术治疗不稳定性Hangman骨折的影响因素及临床疗效。方法:回顾性分析我院2004年5月~2011年5月收治的65例不稳定性Hangman骨折患者,术前采用颅骨牵引C型臂X线机透视观察椎间盘和韧带损伤程度,X线片、CT和MRI观察合并存在的骨折和畸形情况。对椎间隙增宽、C2关节突间部粉碎、C2关节突间部发育细小、C2椎动脉高切迹、C3椎弓根发育细小或无髓腔、C3椎体骨折者采用前路手术;对椎间隙无增宽、C2-C3关节突交锁牵引不能复位、C3椎弓根骨折者采用后路手术。通过临床和影像随访观察两组患者临床疗效。结果:本组患者除C2关节突间部骨折伴C2/C3不稳定外,合并存在的严重损伤和畸形包括:椎间隙增宽9例、C2椎弓根发育细小1例、C2椎动脉高切迹2例、C2关节突间部粉碎骨折3例、C2-C3关节突脱位6例、C3椎体骨折3例、C3椎弓根骨折3例、C3椎弓根细小2例、C3椎弓根无髓腔2例。前路手术15例:椎间隙増宽3例、伴C2关节突间部粉碎骨折2例、C3椎体骨折+C3椎弓根细小1例、C3椎体骨折+C2-C3后方关节突交锁牵引复位1例、C2椎动脉高切迹1例;椎间隙未增宽也需行前路手术者包括C2椎弓根发育细小1例、C3椎体骨折+C2-C3关节突交锁牵引复位1例、C2-C3关节突交锁牵引复位又不能判断C2/3椎间盘和韧带复合体损伤程度1例、C3椎弓根无髓腔2例、C2椎动脉高切迹+C3椎弓根细小1例、关节突间部粉碎骨折+C2-C3关节突交锁复位1例。后路手术50例:其中椎间隙增宽1例、C2-C3关节突脱位交锁牵引不能复位2例、C3椎弓根骨折3例。前、后路手术分别出现并发症7例次(47%)和8例次(16%),手术并发症发生率前路高于后路。结论:根据不稳定Hangman骨折合并C2/3椎间盘韧带结构损伤程度、合并存在的骨折和畸形情况选择前后路手术有利于提高临床疗效。     

后路经关节螺钉固定颗粒状植骨融合治疗寰枢关节不稳定

目的:探讨后路经C1、C2侧块关节螺钉固定、颗粒状松质骨植骨行寰枢关节融合治疗寰枢关节不稳的效果。方法:自1999年12月~2003年4月对58例因齿状突不连、寰椎横韧带断裂或松弛导致寰枢关节不稳定的病例施行了后路经C1、C2侧块关节的螺钉固定术,然后在C1、C2后弓间植入颗粒状松质骨。术中不用钛缆固定寰椎后弓与枢椎棘突。术后不需任何外固定。结果:无手术中损伤脊髓和椎动脉的病例。49例获得随访,时间6个月～3年10个月,平均20个月,全部获得了骨性融合。结论:当寰枢关节不稳定时用两枚螺钉由后路经C1、C2侧块关节固定即可起到足够的稳定作用;在C1、C2后弓间植入颗粒状松质骨可获得很高的融合率。     

Reduction techniques in the management of atlantoaxial subluxation

Background:

The traditional approach to atlantoaxial subluxation which is irreducible after traction is transoral decompression and reduction or odontoid excision and posterior fixation. Transoral approach is associated with comorbidities. However using a posterior approach a combination of atlantoaxial joint space release and a variety of manipulation procedures, optimal or near optimal reduction can be achieved. We analysed our results in this study based on above procedure.

Materials and Methods:

66 cases treated over a 5 year period were evaluated retrospectively. Three cases treated by occipito cervical fusion were not included in the study. The remaining 63 cases were classified into three types. All except two cases were subjected to primary posterior C1-C2 joint space dissection and release followed by on table manipulation which was tailored to treat the type of atlantoaxial subluxation. Optimal or near optimal reduction was possible in all cases. An anterior transoral decompression was needed only in two cases where a bony growth (callus) between the C1 anterior arch and the odontoid precluded reduction by posterior manipulation. All cases then underwent posterior fusion and fixation procedures. Patients were neurologically and radiologically evaluated at regular followups to assess fusion and stability for a minimum period of 6 months.

Results:

Of the 63 cases who underwent posterior manipulation, 49 cases achieved optimum reduction and the remaining 14 cases showed near optimal reduction. Two cases expired in the postoperative period. None of the remaining cases showed neurological worsening after the procedure. Evaluation at 6 months after surgery revealed good stability and fusion in all except three cases.

Conclusion:

Atlantoaxial joint release and manipulation can be used to achieve reduction in most cases of atlantoaxial subluxation, obivating the need of transoral odontoid excision.     

Synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation

Synovial cysts of the cervical spine causing myelopathy are rare. The pathogenesis of these cysts is often attributed to degenerative changes of the facet joints or microtrauma. The authors report a synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation without a congenital anomaly or inflammatory conditions. A 72-year-old man presented with a progressive right-sided myelopathy attributed to a C1-C2 synovial cyst accompanied by atlantoaxial subluxation and C3-C6 spondylosis. Magnetic resonance imaging of the cervical spine showed a large cystic mass compressing the spinal cord located at the C1-C2 junction. A C1 hemilaminectomy, complete evacuation of the cyst contents, and posterior atlantoaxial fusion were performed, and a double-door laminoplasty was also done at C3-C6. The patient showed significant improvement of paresthesia and motor weakness of the right upper and lower extremities immediately after the operation. Synovial cysts should be considered in the differential diagnosis of an extradural mass of the upper cervical spine. Posterior fusion combined with direct excision of the cyst may be the optimum treatment of a synovial cyst at the C1-C2 junction in a patient with atlantoaxial subluxation.     

Osteoarthritis--a rare indication for atlantoaxial fusion. A case report and review of the literature

The authors report a case of C1-C2 fusion which was performed in a 64-year-old woman with unilateral atlantoaxial osteoarthritis, who consulted because of incapacitating occipital pain and decreased cervical rotation without neurological deficit. The diagnosis of unilateral C1-C2 osteoarthritis was confirmed by an open-mouth radiograph, a bone-scan, a computerised tomography scan, and magnetic resonance imaging. C1-C2 fusion was performed using a computer assisted navigation system and posterior instrumentation. This resulted in marked relief of pain, and distinct improvement in quality of life. The prevalence of atlantoaxial osteoarthritis is about four per cent in patients suffering from peripheral or spinal osteoarthritis. However, many primary-care providers are not familiar with this entity. C1-C2 fusion remains rare, due to the difficulties related to the diagnosis of atlantoaxial osteoarthritis, its established non-operative treatment options, and the fact that it has not received adequate attention in the orthopaedic literature. However, based on review of the literature, it can be stated that C1-C2 fusion is an effective and safe procedure providing distinct reduction of pain and increased quality of life in case of failure of conservative treatment.     

前路经枢椎体至寰椎侧块螺钉内固定三维稳定性的实验研究

目的：评价前路经枢椎体至寰椎侧块螺钉内固定三维稳定性。方法：16具成人标本（C0–C3）,对每一标本分别测定完整状态（第1组）、齿状突Ⅱ型骨折（第2组）、后路经关节螺钉内固定术（Magerl技术）（第3组）、前路经枢椎体至寰椎侧块螺钉内固定（第4组）4种状态下的三维运动范围,并进行统计学分析。结果：1组与其他3组、2组与其他3组比较差异有统计学意义（P〈0.001）。前路经枢椎体至寰椎侧块螺钉内固定与后路Magerl螺钉内固定均能显著减少寰枢关节各方向运动范围,两种固定方法差异无统计学意义（P〉0.05）。结论：前路经枢椎体至寰椎侧块螺钉内固定的三维稳定性与后路Magerl螺钉内固定术相当,为寰枢椎不稳定及脱位患者的治疗提供了一种可靠的手术选择。     

C1-C2 transarticular screw fixation: technical aspects.

OBJECTIVE: I review posterior atlantoaxial fusion with transarticular screw fixation, including indications, complications, and operative technique, emphasizing my experience. METHODS: The indications for C1-C2 transarticular screw fixation include traumatic injuries to the atlantoaxial complex, instability resulting from inflammatory disease (rheumatoid arthritis), and congenital abnormalities (os odontoideum). All patients underwent stabilization using cannulated C1-C2 transfacetal screws by the method described by Magerl. Supplemental interspinous fusion with bicortical autologous iliac crest graft and titanium cable was used to restore the posterior tension band by use of the method described by Sonntag's group. Preoperatively, all patients underwent imaging with plain radiographs, magnetic resonance imaging, and axial computed tomography. Patients were maintained in a rigid cervical orthosis postoperatively. RESULTS: Measures used to improve safety and efficacy include patient positioning, fluoroscopic guidance, preoperative magnetic resonance imaging, axial computed tomography, and open reduction of C1-C2 subluxation before screw passage. In this series of 75 patients, fusion was obtained in 72 patients (96%). There were no instances of vertebral artery injury, errant screw placement, instrumentation failure, dural laceration, spinal cord injury, or hypoglossal nerve injury. CONCLUSION: C1-C2 transarticular screw fixation with a posterior tension band construct provides excellent fusion rates with few perioperative complications. Preoperative imaging and meticulous surgical technique improve outcomes.     

前路经寰枢关节螺钉内固定植骨融合治疗寰枢关节不稳

目的探讨前路经寰枢关节螺钉内固定植骨融合治疗寰枢关节不稳的手术方法及临床疗效。方法对23例寰枢关节不稳患者行前路寰枢关节螺钉内固定植骨融合治疗。结果所有患者术后无脊髓、椎动脉和食道损伤等并发症发生。23例获4～45个月随访(平均18.4个月),随访期间所有患者寰枢关节稳定性良好,21例寰枢关节螺钉位置满意,17例获得植骨融合。结论前路经寰枢关节螺钉内固定植骨融合术是治疗寰枢关节不稳的有效方法,能使寰枢关节即刻稳定性获得良好恢复,同时达到植骨融合的目的。     

内镜辅助经高颈前咽后入路治疗颅颈交界区脊椎病变

目的 探讨内镜辅助下经高位颈前咽后入路治疗颅颈交界区脊椎病变的可行性和临床疗效.方法 2007年4月至2009年10月,治疗19例颅颈交界区脊椎病变患者,男9例,女10例;年龄16～62岁,平均41.6岁;陈旧性齿突骨折合并脱位5例,单纯寰椎脱位2例,游离齿突6例,Marfan综合征1例,Kippel-Feil综合征合并颅底凹陷1例,枢椎肿瘤3例,寰枢关节类风湿关节炎1例.均采用内镜辅助下经高位颈前咽后人路完成前路手术操作,其中8例行寰枢关节前路松解复位,8例行齿突切除减压,3例行肿瘤全切与重建.同时一期行后路固定植骨融合术,其中13例采用寰枢椎椎弓根钉固定融合,4例行枕颈融合,2例行C1～C3椎弓根固定融合.结果 8例复位患者均获得解剖复位,8例齿突切除患者行部分或全部齿突切除,3例肿瘤病灶均完全切除.随访6～36个月,平均14个月,全部病例均获骨性融合.14例术前有脊髓症状者末次随访时日本矫形外科学会(Japanese Orthopaedic Association,JOA)评分从术前(9.1±3.3)分提高到术后(14.1±2.9)分JOA改善率优7例,良5例,可1例,差1例.术中出现硬膜破裂1例,经生物蛋白凝胶封堵及术后腰椎蛛网膜下腔置管引流1周后治愈;术后出现吞咽障碍3例,均静脉应用地塞米松及甘露醇,术后3个月内均恢复正常.末次随访时,无一例患者发生感染及内固定松动.结论 内镜辅助经高位颈前咽后入路是治疗颅颈交界区病变的安全、有效、微创的方法.

Abstract：

Objective To assess the feasibility and clinical results of video-assisted high anterior transcervical approach (Smith-Robinson) in treatment of spinal lesions of the craniovertebral junction. Methods Between April 2007 to October 2009, nineteen consecutive patients with spinal lesions of the craniovertebral junction were included in the study. There were 9 males and 10 females aged from 16 to 62 years old with a mean of 32 years. The primary pathologies included 4 cases with chronic odontiod fracture, 2 cases with purely irreducible atlantoaxial dislocation, 6 cases with os odonteideum, 1 case with Marfan synd rome, 1 case with primary basilar invagination from Kippel-Feil syndrome, 3 case with axis tumor and 1 case with irreducible rheumatoid atlantoaxial dislocation. All of the patients underwent combined video-assisted high anterior transcervical procedure and posterior fixation at one-stage. The anterior procedure included atlantoaxil release and reduction (8 cases), odontoidectomy (8 cases), and intralesional extracapsular excision and reconstruction (3 tumor cases). The posterior technique were C1-C2 pedicle screw fixation (13 cases), C1-C3 pedicle screw fixation (2 cases), and occipitalcervical fusion (4 cases). Results Anatomical reduction was achieved in eight cases with anterior release and reduction. Tumors were completely removed in three cases with axial tumor. The mean follow-up was 14 months (6-36 months). All of them achieved solid bone fusion. In the 14 patients with symptoms of spinal cord dysfunction, the average Japanese Orthopaedic Association (JOA)score had improved from 9.1±3.3 preoperatively to 14.1±2.9 postperatively. The improvement rate was excellent for 7 cases, good for 5 cases, fair for lcase and poor for 1 case. One patient experienced leakage of cerebrospinal fluid which was resolved by bioprotein gelatin blocking and lumbar subarachnoid continuous drainage within 1 week. Dysphagia which occurred in 3 cases responded well to dexamethason and mannitol.No infection and hardware failure were observed. Conclusion Video-assisted high anterior transcervical procedure is a safe and effective alternative for treating spinal lesions in the craniovertebral junction.     

Bilateral atlas laminar hook combined with transarticular screw fixation for an unstable bursting atlantal fracture

Introduction  The unstable atlas burst fracture (“Jefferson fracture”) is a fracture of the anterior and posterior atlantal arch with rupture of the transverse atlantal ligament and an incongruence of the atlanto-occipital and the atlanto-axial joint facets. The posterior atlantoaxial fusion is frequently used to reconstruct the stability of atlantoaxial joint. Conventional posterior atlantoaxial fixations are associated with high rates of pseudoarthrosis and chronic atlantoaxial instability. As a modified three-point fixation the bilateral C1-2 transarticular screws combined with C1 laminar hook and bone grafts can provide best biomechanical stability, but no standard protocol has been reported for the use of this fusion technique. A retrospective review of clinical series should be conducted to evaluate the clinical outcome of bilateral atlas laminar hook combined with transarticular screw fixation for unstable bursting atlantal fracture. Materials and methods  From March 2002 to March 2006, there were total 12 cases of unstable atlantal bursting fractures, 10 males and 2 females, age ranging 18–54, with mean of 36 years old. All patients were operated on posterior atlantoaxial fusion using bilateral atlas laminar hook combined with transarticular screw fixation after atlantoaxial joint were reduced and followed up for 12–24 months. The medical records and radiographs of the 12 patients were reviewed. Each patient underwent a complete cervical radiograph series including lateral flexion-extension view and a computed topographic scan. The Frankel grades and ASIA scores were applied to assess the neurologic status. Results  In all patients, a good bony fusion of the atlanto-axial segment was achieved. All patients showed significant improvement of the neurologic defect and no instability on their follow-up plain radiographs and computerized tomography in follow-up interval. Conclusions  For the patients who suffer from the unstable bursting atlantal fracture, the nonoperative methods could carry some clinical complications including infection, nerve injury, etc. and is frequently failure, Posterior atlantoaxial fusion using bilateral atlas laminar hook combined with transarticular screw fixation is an effective treatment. Xiang Guo and Bin Ni contributed equally to the article.     

Occipital-cervical instability.

A retrospective clinicoroentgenographic study was done on 26 patients with atlantoaxial instability, 17 traumatic and nine nontraumatic. All were treated by means of surgical C1-C2 and occipital-C2 stabilization. The traumatic instability was associated with lesions of the odontoid process and the atlas transverse ligament. Instability may be endogenous or associated with fracture of the atlas. Surgical indication was determined by the level of the fracture line, neurologic symptoms, age, and presence of multiple lesions. C1-C2 stabilization by means of wiring and iliac graft was the selected treatment. Fusion between the occipital and C2 segment was indicated in case of irreducible dens pseudoarthrosis. Fracture on the os odontoideum was very unstable and required greater C1-C2 fusion. Nontraumatic C1-C2 instability was either congenital or secondary to pathologic fractures. Rheumatoid arthritis, which produces anterior displacement of the atlas over the dens to more than 10 mm, neurologic symptoms, or untreatable pain must be stabilized by means of C1-C2 fusion. When elevation of the dens or irreducible displacement of the atlas exists, the results were relatively poor. Tumorous instability produced pathologic fracture of the body of the axis and had to be treated with C1-C2 wiring on bone cement. Down's syndrome instability required occipitoaxial fusion and strict postoperative immobilization.     

手术治疗寰枢椎不稳

目的对寰枢椎不稳的手术治疗进行探讨。方法31例中齿状突骨折15例,寰椎横韧带断裂4例,枢椎原发肿瘤4例,寰椎椎弓陈旧性骨折2例,类风湿性枕颈部发育畸形6例。28例行颈后路手术,包括枕颈融合术14例,寰枢椎融合术13例,肿瘤病灶清除后植骨1例;另3例枢椎经口腔病灶清除加钛网融合器椎间植骨及钛板将环椎前弓与G固定,其中2例分别行前后路手术。结果31例均获随访,时间3个月～10年,平均13．5个月,全部骨性愈合。术前合并神经系统症状26例,术后症状明显改善14例,加重3例。结论对于由寰枢椎骨折脱位、畸形、肿瘤及横韧带断裂等引起的寰枢椎不稳,应早期进行后路前路融合术。充分控制寰枢椎活动,精心准备植骨床是保证手术成功的关键。     

Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability

Purpose

Even though transarticular screw (TAS) fixation has been commonly used for posterior C1–C2 arthrodesis in both traumatic and non-traumatic lesions, anterior TAS fixation C1–2 is a less invasive technique as compared with posterior TAS which produces significant soft tissue injury, and there were few reports on percutaneous anterior TAS fixation and microendoscopic bone graft for atlantoaxial instability. The goals of our study were to describe and evaluate a new technique for anterior TAS fixation of the atlantoaxial joints for traumatic atlantoaxial instability by analyzing radiographic and clinical outcomes.

Methods

This was a retrospective study of seven consecutive patients with C1–C2 instability due to upper cervical injury treated by a minimally invasive procedure from May 2007 to August 2009. Bilateral anterior TAS were inserted by the percutaneous approach under Iso-C3D fluoroscopic control. The atlantoaxial joint space was prepared for morselized autogenous bone graft under microendoscopy. The data for analysis included time after the injuries, operating time, intraoperative blood loss, X-ray exposure time, clinical results, and complications. Radiographic evaluation included the assessment of atlantoaxial fusion rate and placement of TAS. Bone fusion of the atlantoaxial joints was assessed by flexion extension lateral radiographs and 1-mm thin-slice computed tomography images as radiographic results. Clinical assessment was done by analyzing the recovery state of clinical presentation from the preoperative period to the last follow-up and by evaluating complications.

Results

A total of 14 screws were placed correctly. The atlantoaxial solid fusion without screw failure was confirmed by CT scan in seven cases after a mean follow-up of 27.5 months (range 18–45 months). All patients with associated clinical presentation made a recovery without neurologic sequelae. Postoperative dysphagia occurred and disappeared in two cases within 5 days after surgery. There were no other complications during the follow-up period.

Conclusions

Percutaneous anterior TAS fixation and microendoscopic bone graft could be an option for achieving C1–C2 stabilization with several potential advantages such as less tissue trauma and better accuracy. Bilateral TAS fixation and morselized autograft affords effective fixation and solid fusion by a minimally invasive approach.     

Atlantoaxial transarticular screw fixation and posterior fusion using ultra-high-molecular-weight polyethylene cable

This article attempts to evaluate the effectiveness of the ultra-high-molecular-weight polyethylene (UHMW-PE) cable system in atlantoaxial transarticular screw fixation and posterior fusion through the clinical results of 10 postoperative patients with atlantoaxial subluxation secondary to rheumatoid arthritis. Among them, one patient with only one screw placed owing to an anomalous vertebral artery had the correction loss of the 3-mm atlas-dens interval after surgery. Another patient had a second operation to remove the screw and cable after 2 years 11 months because a unilateral transarticular screw had come to protrude through the lateral mass of the atlas ventrally. All patients had achieved C1-C2 osseous fusion without any complications associated with this cable system. The UHMW-PE cable is a very useful material as sublaminar wiring in atlantoaxial transarticular screw fixation and posterior fusion.     

Atlantoaxial arthrodesis using C1-C2 transarticular screw fixation in a case of Morquio syndrome

Prophylactic or therapeutic arthrodesis is recommended for atlantoaxial instability in Morquio syndrome. Occipitocervical fusion, the common approach for upper cervical fusion in Morquio syndrome sacrifices the movements at the occipitoatlantal joints. The use of C1-C2 transarticular screws for achieving C1-C2 arthrodesis, without compromising mobility at the occipitoatlantal joint in Morquio syndrome has not been reported. We report a case of Morquio syndrome with atlantoaxial instability and odontoid hypoplasia, where we successfully achieved C1-C2 arthrodesis using transarticular screws and bone graft. The advantages of this method over other methods of atlantoaxial arthrodesis in Morquio syndrome have also been discussed.     

Failure of posterior titanium atlantoaxial cable fixation.

BACKGROUND CONTEXT: The operative treatment of rotatory atlantoaxial instability remains controversial. The use of cable fixation has largely replaced the use of wire for interlaminar fixation. Although cable fixation offers biomechanical advantages over wire fixation, it is still at risk of fatigue failure. The authors were unable to locate any published reports of fatigue failure of titanium cables in the fixation of atlantoaxial instability. PURPOSE: The purpose of this case study is to describe an unusual case of fatigue failure of a titanium cable used to aid in atlantoaxial fusion for the treatment of rotatory atlantoaxial instability. STUDY DESIGN: Case study. METHODS: We reviewed the medical records and X-rays of a patient with rotatory atlantoaxial instability treated with posterior C1-C2 fusion and atlantoaxial fixation with a titanium multistranded cable, who developed fracture of the cable and migration of the cable into the spinal canal. RESULTS: The patient was revised with removal of the broken cable, repair of the pseudarthrosis and fixation with atlantoaxial screws. CONCLUSION: Interlaminar fixation with cables or wires is at risk for failure with potential migration of the wire or cable into the spinal canal. The authors found that failure of the cables or wire can be salvaged with application of transarticular screws.