Die rheumatische Instabilität der Halswirbelsäule

Background

The involvement of the cervical spine in rheumatoid arthritis (RA) continues to be of clinical importance even in this age of biologics. Pathophysiological changes begin with an isolated atlantoaxial subluxation and may progress to a complex craniocervical and subaxial instability. The onset of cervical myelopathy can occur at any time and leads to a deterioration of the prognosis for the patient.

Therapy

Treatment of the rheumatoid cervical spine should be aimed at improvement of the symptoms and prevention of further progress of the disease. In the case of instability, this is only possible by surgical treatment. The increasing usage of biological agents has led to a change in the clinical picture of the cervical involvement in RA patients. There are fewer patients presenting with isolated atlantoaxial instability. In contrast, the number of patients with complex craniocervical and/or subaxial instabilities is increasing. Complex cervical instabilities may require a longer fusion from the occiput to the upper thoracic spine. Modern operative techniques make this complex surgery also possible in severely disabled patients with a high comorbidity.

     

Relation between alignments of upper and subaxial cervical spine: a radiological study

Objective  

To reveal the relation between alignments of upper and subaxial cervical spine and deduce the optimal atlantoaxial fusion angle by a radiological study.     

Does atlantoaxial dislocation influence the subaxial cervical spine?

Introduction

Previous studies have reported that the alignments of the occipital-cervical and subaxial spine were closely interrelated in asymptomatic individuals; however, none have focused on a population with atlantoaxial dislocation.

Material and methods

From 2007 to 2011, 298 patients with atlantoaxial dislocation and atlas occipitalization were studied. Angles formed between Occiput-C2 and C2–C7 were measured. The relationship between the alignment of the occipital-cervical junction and the subaxial cervical spine was evaluated.

Results

The range of values for the angles measured was as followed: the Occiput-C2 angles were −35.2° to 44.8°, and the C2–C7 angles were −17.4° to 77.8°. Statistically significant negative correlations were observed between the Occiput-C2 and C2–C7 angles.

Conclusion

Anterior dislocations of the atlas are associated with diminished lordosis or even kyphosis of the occipital-cervical junction, and result in compensatory hyperlordosis of the subaxial cervical spine, collectively presenting as a “swan neck” deformity. Atlantoaxial dislocation may influence the global cervical alignment.     

Alterations in axial curvature of the cervical spine with a combination of rotation and extension in the conventional anterior cervical approach

Purpose

Alterations of three-dimensional cervical curvature in conventional anterior cervical approach position are not well understood. The purpose of this study was to evaluate alignment changes of the cervical spine in the position. In addition, simulated corpectomy was evaluated with regard to sufficiency of decompression and perforation of the vertebral artery canal.

Methods

Fifty patients with cervical spinal disorders participated. Cervical CT scanning was performed in the neutral and supine position (N-position) and in extension and right rotation simulating the conventional anterior approach position (ER-position). Rotation at each vertebral level was measured. With simulation of anterior corpectomy in a vertical direction with a width of 17 mm, decompression width at the posterior wall of the vertebrae and the distance from each foramen of the vertebral artery (VA) were measured.

Results

In the ER-position, the cervical spine was rotated rightward by 37.2° ± 6.2° between the occipital bone and C7. While the cervical spine was mainly rotated at C1/2, the subaxial vertebrae were also rotated by several degrees. Due to the subaxial rotation, the simulated corpectomy resulted in smaller decompression width on the left side and came closer to the VA canal on the right side.

Conclusions

In the ER-position, the degrees of right rotation of subaxial vertebrae were small but significant. Therefore, preoperative understanding of this alteration of cervical alignment is essential for performing safe and sufficient anterior corpectomy of the cervical spine.     

Surgical procedures on the cervical spine in polyarthritis.

Summary Patients with rheumatoid arthritis suffer frequently from instabilities and deformities of the cervical spine which require surgical treatment. The most frequent indication for surgery represents the transverse atlantoaxial instability. As long the atlantoaxial instability remains reducible in extension a limited posterior exposure and screw fixation is adequate. Only situations with fixed dislocations and signs of myelopathy require anterior transoral decompression with simultaneous occipitocervical fusion. In the lower cervical spine, kyphotic deformities require anterior decompression and posterior stabilization in the case of electrophysiologically confirmed neurological deficits. A combined procedure with anterior vertebrectomy and decompression and posterior plate fixation is indicated since the poor bone quality rarely allows anterior stable fixation.      

Morphometric subaxial lateral mass evaluation allows for preoperative optimal screw trajectory planning

Purpose

Lateral mass (LM) fixation has become a standard in cervical spine instability treatment; however, maximal biomechanical stability combined with low morbidity remains a challenge. We evaluated our own patient cohort for bicortical screw placement and complication rates and investigated optimal screw trajectories with preoperative multiplanar computed tomography (CT) scans.

Methods

Fifty-five patients were retrospectively evaluated after LM fixation at various subaxial cervical spine levels with a modified Magerl technique. Postoperative CTs and clinical records were used to determine LM anatomy, screw lengths, bicortical screw percentages, and complication rates. Additionally, 3D CT subaxial cervical spine data sets from 45 additional subjects with clinical indications for cervical spine imaging were evaluated. Subject LM geometries (thickness) were evaluated at different sagittal angulations (strict sagittal, 20°, 30° and the optimal angulation) for the optimal screw trajectories at the C3–C7 segments.

Results

In total, 284 LM screws were placed, with a mean screw length of 16 mm and an 88 % bicortical bone purchase. Additionally, a 3.8 % malplacement rate was observed. LM thickness varied substantially between each subaxial cervical level and at each of the investigated angulations. The optimal angulation, at which LM thickness was maximal, increased continuously from C3 (14°) to C7 (38°). This increase permitted 8 % (C3) to 39 % (C7) gains in screw length compared with the strict sagittal plane assessments.

Conclusions

The optimal LM trajectory varied for each subaxial segment. The knowledge of LM geometry allows for safe, long and even bicortical screw placements using preoperative sagittal CT imaging evaluations.     

Transoral anterior revision surgeries for basilar invagination with irreducible atlantoaxial dislocation after posterior decompression: a retrospective study of 30 cases

Purpose

To report the surgical techniques and clinical results of one-stage transoral anterior revision surgeries for basilar invagination (BI) with atlantoaxial dislocation (AAD) after posterior decompression.

Methods

From September 2008 to June 2012, 30 patients (16 men and 14 women) who had BI with irreducible atlantoaxial dislocation (IAAD) after posterior decompression underwent anterior revision surgeries in our department. Dynamic cervical radiographs, computed tomographic scans and magnetic resonance imaging were obtained pre- and postoperatively to assess the degree of AAD and ventral compression on the cervical cord. The JOA scoring system was used to evaluate the neurological status. The revision surgeries were conducted by anterior approach, using the transoral atlantoaxial reduction plate (TARP) system.

Results

The revision surgeries were successfully performed in all of the cases. The average follow-up duration was 16 months (range 6–39 months). For all of the cases, complete or more than 50 % reduction and decompression of C1–C2 were achieved. The cervicomedullary angle was improved by an average of 32.9°. Bone fusion was achieved within 3–6 months in all of the cases. Clinical symptoms were alleviated in 29 patients (96.7 %) and stabilised in 1 patient (3.3 %). No patients have developed recurrent or progressive atlantoaxial instability so far.

Conclusion

Anterior revision surgeries using the TARP system achieved reduction, decompression and fixation of C1–C2 in one stage for BI with IAAD. This technique offers an effective, simple and safe method for the revision of such cases after posterior decompression.     

Die transartikuläre C1-C2-Verschraubung

Background

Transarticular dorsal screw fixation of atlantoaxial instability in the elderly is seldom described in the literature. This study presents the results of this technique in patients aged at least 70 years. A modified method of indirect screw fixation is used in which soft tissue dissection is reduced compared to the classic procedure.

Patients and methods

Between 1998 and 2005 a total of 36 patients with acute or chronic traumatic instability of the atlantoaxial complex were treated surgically. The average age was 80.1 years (70–93 years). Seven patients (19.4%) had associated injuries. The operative technique was standard. The duration of radiological follow-up averaged 23 months (12–57 months) whereas clinical follow-up was for 38 months (12–72 months).

Results

There were no intraoperative complications. Of the total 72 screws inserted, 2 (2.8%) proved to be incorrectly positioned. There were complications not associated with the procedure in 16 patients (44.4%). Nosocomial infections and falls were the most common complications. Two deaths occurred within the first postoperative month. Four more patients died in the follow-up period as a result of diseases not associated with the trauma. Of the 30 surviving patients, 28 (93.3%) were followed up clinically and radiologically. Bony dorsal fusion was documented in every patient followed up. Further operation on the cervical spine was not required in any patient.

Conclusion

The presented technique of transarticular C1-C2 screw fixation is associated with reliable fusion rates and good functional results. The procedure can be recommended for atlantoaxial instability in the elderly.     

Surgical aspects of the cervical spine in rheumatoid arthritis

Approximately 20% percent of the patients with rheumatoid arthritis show pathology in the cervical spine. The translational instability between axis and atlas might be painful and leads in the long term to myelopathic changes due to chronic traumatization of the myelon. Ongoing osseous resorption of the lateral masses of the atlas cause upward migration of the dens into the foramen magnum. In the subaxial cervical spine, the inflammatory process causes instability and deformity. Neck pain is the most common indication for surgery, but neurological symptoms with myelopathy or radicular deficits might be the primary cause for surgery. Neurophysiological investigation is suitable to obtain objective results. Stabilization of the atlantoaxial segment is the most common procedure for treatment of atlantoaxial instability. It is performed by screw fixation technique from a posterior approach. In case of severe occipitocervical dislocation, the fixation has to be extended to the occiput. Persistent dislocation or compression by the dislocated dens has to be treated by transoral decompression. In the subaxial spine, instabilities may be treated by posterior plate fixation with lateral mass screws or pedicle screws. Concomitant nar-rowing of the spinal canal should be approached by anterior decompression with corpectomy and/or posterior laminectomy. The timing of surgery in rheumatoid patients is crucial to obtain satisfactory clinical results.     

Subaxial cervical juxtafacet cysts: single institution surgical experience and literature review

Objectives

Juxtafacet cysts (JFCs) of the subaxial cervical spine are rare causes of neurological deficits. Their imaging characteristics, relationship to segmental instability, and potential for inducing acute symptomatic deterioration have only been described in a few case reports and small case series. The objective of the current study was to review the surgical experience at our center and across the literature to better define these variables.

Methods

A single-institution, multisurgeon series of 12 consecutive patients (mean age 63.4 years, range 52–83 years) harboring 14 JFCs treated across 9 years was retrospectively reviewed. Clinical history, neurological status, preoperative imaging, operative findings, pathology, and postoperative outcomes were obtained from medical records. The mean follow up was 9.2?±?7.8 months. A literature review identified 35 studies with 89 previously reported cases of surgically treated subaxial cervical JFCs.

Results

Consistent with previously reported cases, most JFCs in our series involved the C7/T1 level. Nine patients reported axial neck pain, 12 patients had radicular symptoms, four patients had myelopathy, and one patient experienced rapid neurological decline attributable to cystic hemorrhage. Cyst expansion without hemorrhage caused subacute deterioration in one patient. All patients experienced sensory and/or motor improvement following surgical decompression. Preoperative axial neck pain improved in eight of nine patients (89 %). Seven out of 12 patients (58 %) underwent fusion either at the time of decompression (six patients) or at a delayed timepoint within the follow-up period (one patient). Prior history of cervical instrumentation, hypermobility on dynamic imaging, and other risk factors for segmental instability were more common in our series than in previous reports.

Conclusions

Our findings lead us to advocate for early decompression rather than prolonged conservative treatment, for pre- and postoperative dynamic imaging, and for fusion in selected cases as an initial surgical consideration.     

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.     

Chirurgische Aspekte der rheumatischen Halswirbelsäule

Approximately 20% percent of the patients with rheumatoid arthritis show pathology in the cervical spine, mainly in the atlantoaxial segment. The translational instability between axis and atlas might be painful and leads in the long term to myelopathic changes due to chronic traumatization of the myelon. Ongoing osseous resorption of the lateral masses of the atlas cause upward migration of the dens into the foramen magnum. In the subaxial cervical spine, the inflammatory process causes instability and deformity. Neck pain is the most common indication for surgery, but neurological symptoms with myelopathy or radicular deficits might be the primary cause for surgery. It has to be kept in mind that clinical assessment in rheumatoid patients might be extremely difficult since previous surgeries on various articulations of the extremities make interpretation of clinical findings difficult. Neurophysiological investigation is suitable to obtain objective results. Stabilization of the atlantoaxial segment is the most common procedure for treatment of atlantoaxial instability. It is performed by screw fixation technique from a posterior approach. In case of severe occipitocervical dislocation, the fixation has to be extended to the occiput. Persistent dislocation or compression by the dislocated dens has to be treated by transoral decompression. In the subaxial spine, instabilities may be treated by posterior plate fixation with lateral mass screws or pedicle screws. Concomitant narrowing of the spinal canal should be approached by anterior decompression with corpectomy and/or posterior laminectomy. The timing of surgery in rheumatoid patients is crucial to obtain satisfactory clinical results.     

寰枢椎骨折脱位后路内固定植骨融合术

[目的]探讨寰枢椎骨折脱位后路内固定植骨融合术的方法和疗效。[方法]在气管插管全麻下对26例寰枢椎骨折脱位的患者施行后路内固定植骨融合术。对有椎体后弓和椎板骨折者采用枕颈内固定（Aixs）植骨融合术，对无椎体后弓和椎板骨折且无需行椎管减压的寰枢椎骨折采用椎板夹（Apofix）内固定。[结果]随访5～60个月，平均16．8个月。全组病例未发生椎动脉或脊髓损伤等并发症。术后临床症状均得到较好改善，X线片复查提示椎体侧块关节突和枕骨髁部螺钉位置良好，无松动或断钉现象，植骨3个月均达到骨性融合。[结论]Aixs内固定植骨融合术或Apofix内固定术是治疗寰枢椎骨折脱位的有效方法之一。     

Fusion of the cervical spine for instability

The orthopedic and neurosurgical literature is neither clear nor consistent in describing an unstable cervical spine. In a series of 25 patients treated by arthrodesis of the cervical spine for instability, 12 had Gallie fusions at the atlantoaxial level. Eight of those fusions were performed for rheumatoid arthritis. In three patients persistent subluxation of the atlas on the axis occurred because the wires were not fully tightened in areas of poor-quality bone. Stable fixation with relief of symptoms was achieved in all patients who had fusions at the subaxial level. Several of these patients had had prolonged nonsurgical treatment. With rheumatoid bone of poor quality, the surgeon must be very careful to tighten the wires only enough to secure a stable reduction for treatment of subaxial cervical instability. Since stability achieved by healing of soft tissue is generally unreliable, prolonged periods of nonsurgical treatment are not justified for traumatic instability.     

Atlantoaxial transarticular screw fixation and posterior fusion using polyester cable: a 10-year experience

Purpose

To retrospective review the clinical outcomes of the modified operative technique using a polyester suture material (Ethibond* Excel) for atlantoaxial transarticular screw fixation and posterior fusion.

Methods

The retrospective reviews were conducted from 2002 to 2012. The patient’s medical record reviews included demographic data, cause of atlantoaxial instability, orthopedic and surgical history, clinical presentation, radiographic finding including plain radiography, complications, operative detail, and outcome of treatment. Fusion of C1–C2 was defined as either graft consolidation or absence of C1–C2 movement on lateral flexion–extension radiograph.

Results

Twenty-three patients demonstrated clinical and radiographic evidence of atlantoaxial instability (13 men and 10 women, with a mean age of 42 years). Majority of atlantoaxial instability was caused by trauma. Most common clinical symptom was neck pain with or without cervical myelopathy. Bilateral screws were placed in 18 of the 23 patients. Five patients underwent placement of unilateral screws. The 13 patients were inserted by screws with diameter 4.0 mm. The means screw length was 40.33 mm. The means of operative time and estimated blood loss were 3.6 h and 234 ml, respectively. The mean of follow-up duration was 18 months. All 41 screws were positioned satisfactorily in C1 lateral mass. All 23 patients achieved fusion (100 % fusion rate). After a period of follow-up, 9 of the 10 neurological deficit patients had completely recovered.

Conclusions

We concluded that the atlantoaxial transarticular screw fixation and posterior fusion using polyester cable can be used for C1–2 fusion with a high fusion rate and less complications in various cases.     

Transfacet screw fixation of the subaxial cervical spine—how I do it?

Background

Transfacet screw fixation is a biomechanically effective way of fusing the subaxial cervical spine. The technique used by this author is described.

Methods

With the patient in prone position, a conventional posterior exposure of the cervical spine is done. The entry point used by this author is 2 mm above the middle of the lateral mass without any lateral angulation. Under fluoroscopic guidance the facet is drilled until all the four cortical surfaces are purchased. Then the depth is measured to assess the length of the screw required. This is followed by tapping and screw insertion both of which are done under fluoroscopic control. All screws are placed prior to laminectomy to decompress the cervical cord.

Conclusions

This is a simple, inexpensive and biomechanically effective way of stabilizing the subaxial cervical spine.     

Cervical Spine Surgery: An Historical Perspective

Background

Continued innovation in surgery requires a knowledge and understanding of historical advances with a recognition of successes and failures.

Questions/purposes

To identify these successes and failures, we selectively reviewed historical literature on cervical spine surgery with respect to the development of (1) surgical approaches, (2) management of degenerative disc disease, and (3) methods to treat segmental instability.

Methods

We performed a nonsystematic review using the keywords “cervical spine surgery” and “history” and “instrumentation” and “fusion” in combination with “anterior approach” and “posterior approach,” with no limit regarding the year of publication. Used databases were PubMed and Google Scholar. In addition, the search was extended by screening the reference list of all articles.

Results

Innovative surgical approaches allowed direct access to symptomatic areas of the cervical spine. Over the years, we observed a trend from posterior to anterior surgical techniques. Management of the degenerative spine has evolved from decompressive surgery alone to the direct removal of the cause of neural impingement. Internal fixation of actual or potential spinal instability and the associated instrumentation have continuously evolved to allow more reliable fusion. More recently, surgeons have developed the basis for nonfusion surgical techniques and implants.

Conclusions

The most important advances appear to be (1) recognition of the need to directly address the causes of symptoms, (2) proper decompression of neural structures, and (3) more reliable fusion of unstable symptomatic segments.

     

Rheumatoid arthritis of the cervical spine. Current concepts for diagnosis and therapy

The involvement of the cervical spine in patients with rheumatoid arthritis (RA) is common,and has recently received growing attention. In the early stage of the disease, there is an isolated atlantoaxial subluxation (AAS). With further progression, osseous destruction of the joints can lead to vertical instability. While the involvement of the middle and lower cervical spine can cause a subaxial instability, neurological deficits can occur at any time. The onset of cervical myelopathy in patients with RA is often missed because of additional problems related to the hands and feet. If patients show clear symptoms of cervical myelopathy, the progression of the disease cannot be stopped by conservative treatment. Other indications for operative treatment are severe pain and radiological evidence of progressive instability. In the case of an isolated AAS, fusion can be restricted to the C1/C2 segment. If there is evidence for vertical or subaxial instability, an occipitocervical fusion has to be performed. To avoid instability adjacent to the fusion, the surgeon must check for signs of potential subaxial instability. If this is the case, fusion should include the entire cervical spine. Additional transoral decompression may be necessary when there is persistent retrodental pannus or osseous compression by an irreducible transverse dislocation or cranial migration of the dens. Non-ambulatory myelopathic patients are more likely to present severe surgical complications with limited prospects of functional recovery. Therefore, it is important to avoid the development of severe cervical myelopathy by early surgical intervention.     

后路寰枢椎椎弓根螺钉结合单侧枢椎棘突椎板钉固定治疗寰枢椎不稳的临床疗效

 目的探讨后路寰枢椎椎弓根螺钉结合单侧枢椎棘突椎板钉加同种异体骨植骨融合术治疗寰枢椎不稳的临床疗效。方法回顾性分析2010年3月至2014年4月,采用枢椎棘突椎板钉结合寰枢椎椎弓根固定植骨融合术治疗10例寰枢椎不稳定患者资料,男6例,女4例;年龄16~62岁,平均39岁;单侧椎动脉高跨畸形伴寰枢椎不稳定7例,枢椎单侧关节突破坏累及椎弓根致寰枢椎不稳定3例。患者均表现为颈部活动受限及疼痛,VAS评分1~8分,平均（3.70±2.11）分,其中3例伴肌力下降及感觉异常。术前常规行影像学检查,术后7 d及1、3、6、12个月行X线和CT检查,了解内固定位置及植骨融合情况;比较手术前后VAS评分。结果10例患者均获得随访,随访时间9~18个月,平均13个月。术中无一例发生颈脊髓和椎动脉损伤,除1例颈部肌肉肥厚者需另开软组织通道置入螺钉外,其余均一次性置钉成功。1例术后第3天切口出现渗液,考虑为同种异体骨排异反应,对症换药后5天停止渗液,余切口均一期愈合。术后VAS评分（1.01±0.89）分,较术前明显减轻。术后X线片示颈椎序列恢复良好,CT示1例患者寰椎椎弓根钉道内侧皮质破损,椎管未侵犯,余螺钉位置正常;术后6个月X线片及CT检查均见骨性融合。结论寰枢椎椎弓根螺钉结合单侧枢椎棘突椎板钉植骨融合术治疗寰枢椎不稳,近期疗效肯定。     

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。