Periodontoid pannus migration into the spinal canal with reduction of rheumatoid atlantoaxial subluxation: a case report

 We report a patient with rheumatoid arthritis in whom periodontoid pannus migrated into the spinal canal with reduction of atlantoaxial subluxation. In this case, magnetic resonance imaging in the extension position was valuable for determining the therapeutic strategy. Received: February 5, 2002 / Accepted: June 18, 2002 Offprint requests to: H. Ishihara     

颈后路手术治疗类风湿性寰枢椎不稳

目的：对类风湿性寰枢椎不稳患者颈后路植骨融合、内固定手术进行探讨。方法：对21例类风湿性寰枢椎不稳患者采用颈后路植骨融合、内固定手术，其中7例可复性寰枢椎半脱位行寰枢椎间植骨钛缆或Apofix固定术；14例难以复位者行枕颈间植骨cervifix固定术。结果：随访6～28个月(平均18个月)。21例均无并发症发生，X线显示均获骨性融合，19例患者神经功能获不同程度改善，2例虽无改善但无神经损害发展。结论：颈后路植骨融合、内固定术可为类风湿性寰枢椎不稳的患者提供牢固的融合固定，且以早期手术为佳。     

Complete reduction of retro-odontoid soft tissue mass in os odontoideum following the posterior C1-C2 tranarticular screw fixation.

STUDY DESIGN: A case report of os odontoideum with retro-odontoid soft tissue hypertrophy treated by the transarticular screw fixation. OBJECTIVES: To present a case of os odontoideum that showed complete reduction of retro-odontoid soft tissue mass caused by atlantoaxial subluxation after the C1-C2 transarticular screw fixation. SUMMARY OF BACKGROUND DATA: Hypertrophy of the periodontoid soft tissue has been reported to be associated with chronic atlantoaxial subluxation and progressive myelopathy. While the rheumatoid pannus has been reported to become reduced of disappear after fixation of the unstable segment, the reduction of the hypertrophied soft tissue mass has never been reported in atlantoaxial subluxation of nonrheumatoid origin, especially in the case of os odontoideum. METHODS: Posterior C1-C2 transarticular screw fixation was performed in a patient with os odontoideum, who showed signs of progressive myelopathy by the compression of retro-odontoid soft tissue mass and atlantoaxial subluxation. RESULTS: The fixation of atlantoaxial subluxation achieved not only the complete reduction of the retro-odontoid soft tissue mass, but also clinical improvement of the myelopathy. CONCLUSIONS: Posterior atlantoaxial fixation is worth trying in slow progressing myelopathy by the compression of hypertrophy of the soft tissue even in nonrheumatoid atlantoaxial subluxation, thereby obviating the need for direct removal of the mass via the transoral route.     

Remarkable reduction or disappearance of retroodontoid pseudotumors after occipitocervical fusion. Report of three cases

Retroodontoid or periodontoid pseudotumor unassociated with rheumatoid arthritis or hemodialysis is clinically rare. The authors report three cases of retroodontoid pseudotumor that they treated surgically. All patients exhibited myelopathy of the upper cervical spinal cord. Plain radiography depicted atlantoaxial instability in two of the three patients. Spinal cord compression caused by a mass lesion in all patients was clearly demonstrated on magnetic resonance images. In two patients, the mass lesion was not limited to the retroodontoid region and expanded continuously to the cranial base. Posterior laminectomy of the atlas and occipitocervical fusion were performed. After surgery, the pseudotumor disappeared in two cases and was clearly reduced in one case, and neurological symptoms also improved. Retroodontoid pseudotumor is a lesion for which symptomatic improvement can be expected with posterior decompression and fusion, even without direct tumor excision.     

Transoral anterior approach for extensive anterior decompression at the C3 vertebra level in a patient with severe atlantoaxial vertical subluxation and rheumatoid arthritis

STUDY DESIGN: We report a successful extensive transoral anterior decompression for an elderly patient with myelopathy and occipitalgia due to severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with rheumatoid arthritis (RA). OBJECTIVE: To describe the treatment of an exceptional pathological condition involving severe vertical subluxation. SETTING: University-affiliated hospital in Gifu, Japan. METHODS: A 73-year-old woman was referred to our clinic because of myelopathy and occipitalgia due to severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with RA. Plain radiographs revealed severe atlantoaxial vertical subluxation and sagittal magnetic resonance (MR) imaging revealed severe compression of the spinal cord at the level of the C2/3 disc space due to both posterior subluxation of C2 and rheumatoid pannus at the C2/3 disc space. As MR images demonstrated that the C2/3 disc space was located just behind the retropharyngeal wall, we performed successful anterior decompression from C2 to C3 via the standard transoral approach without mandibular osteotomy. RESULTS: The patient has been followed for 4 years and her symptoms are currently much improved without further surgical treatment. CONCLUSIONS: The present case illustrates that severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with RA can be treated successfully by anterior decompression of C2 and C3 via the standard transoral approach.     

Occipitocervical fusion for reduction of traumatic periodontoid hypertrophic cicatrix. Case report

Periodontoid hypertrophic cicatrix resulting from trauma, as demonstrated by magnetic resonance (MR) imaging, is essentially the same as that seen in rheumatoid arthritis. Recent reports suggest that, in rheumatoid arthritis, occipitocervical fusion without transoral decompression of the pannus is adequate for resolution of this anterior lesion. A case of traumatic periodontoid cicatrix is presented in which posterior fusion resulted in reduction of the anterior mass lesion, clearly demonstrated by MR imaging. The etiology of periodontoid hypertrophic scarring, both traumatic and rheumatoid, is discussed in light of MR findings, and treatment implications are considered.     

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.     

寰枢关节类风湿性关节炎的影像学分析(附21例报告)

目的评估累及寰枢关节的21例RA患者经联合治疗的临床效果及其影像学特征。方法对平均病程为7．95年（2～26年）的21例患者行MTX＋其他DMARDs的联合治疗,同时行临床和影像学评估,明确16例存在寰枢椎前向半脱位、3例垂直半脱位、2例侧方半脱位。6例有明显枕颈部症状的寰枢不稳息者行后路寰枢或枕颈融合治疗。结果联合治疗的有效率为85．7％。RA病程越长,越易发生寰枢椎不稳和椎管矢状径减小,本组前向寰枢椎半脱位最常见。6例手术患者的齿突周围血管翳在随访中较术前明显减小。结论对累及寰枢关节的RA患者,无论有无寰枢椎不稳、有无症状或脊髓损伤的体征,均可成功行影像学评估且行MTX＋其他DMARDs的联合治疗可取得较好的疗效;为防止枕颈部脊髓压迫,宜对此类患者行常规、定期的临床和影像学评估。     

经后路寰枢椎椎弓根螺钉固定融合术治疗寰枢椎失稳

目的:探讨应用寰枢椎椎弓螺钉固定技术治疗寰枢椎失稳的临床疗效。方法:对2003年6月至2010年3月对收治的32例寰枢椎失稳患者采用寰枢椎椎弓根螺钉技术进行治疗,其中男21例,女11例;年龄28～66岁,平均42.5岁;齿状突骨折18例,先天性游离齿状突7例,Jefferson骨折合并齿状突骨折4例,类风湿性关节炎致寰枢椎不稳3例。所有患者均伴有寰枢椎半脱位或失稳。术前JOA评分4～14分,平均(9.1±0.3)分。术前完善颈椎X线(包括动力位片)、螺旋CT三维重建及MRI等影像学检查,在CT轴位片上对寰枢椎椎弓根螺钉的置入点、置入角度及钉道长度等数据进行测量,并行颅骨牵引术。手术在全麻下进行,直视下完成寰枢椎椎弓根螺钉的置入、复位和植骨融合,植骨块被向后预弯的横联紧紧卡压于寰椎后弓与枢椎椎板棘突之间。比较术前和术后6个月的JOA评分,并计算改善率。结果:32例患者共置入寰枢椎螺钉128枚,无脊髓、神经根和椎动脉损伤发生。所有患者获随访,时间6～48个月,平均16个月。术后JOA评分11～17分,平均(15.9±0.2)分,平均改善率为86.1%。骨折的齿状突均完全愈合,植骨块全部融合,无内固定断裂和松动。结论:寰枢椎椎弓根螺钉固定技术是治疗寰枢椎失稳的有效方法,具有固定牢靠,操作相对安全方便、融合率高等优点,值得临床应用。     

Pannus resolution after occipitocervical fusion in a non-rheumatoid atlanto-axial instability

Periodontoid pseudotumor or pannus is considered to be an inflammatory mass most frequently associated with rheumatoid arthritis. Transoral resection of the pannus has been the treatment of choice for patients with associated myelopathy, followed in many instances by posterior stabilization. However, some authors have reported resolution of pannus associated with rheumatoid arthritis and other forms of chronic atlanto-axial instability only after posterior stabilization. We report a case of a 69-year-old man who presented with a rapidly progressing myelopathy due to a retro-odontoid mass produced by chronic atlanto-axial instability associated with an occipital assimilation of C1 and tight posterior fossa. An urgent posterior fossa craniectomy followed by occipitocervical fixation was performed. After surgery, the patients clinical condition improved and 1 year after surgery was asymptomatic, walked without any help and had normal strength. Control MR showed complete resolution of the retro-odontoid pannus.     

Retroodontoid pseudotumor resected by a high cervical lateral approach in a rheumatoid arthritis patient: a case report

A retroodontoid pseudotumor is a nonneoplastic mass arising posterior to the odontoid process. We describe a 67-year-old woman admitted to our hospital with numbness of the left upper extremity, dysbasia, and impairment of fine motor movement of the fingers. She was diagnosed with myelopathy due to a retroodontoid pseudotumor underlying rheumatoid arthritis. According to previously published reports, reduction of the pseudotumor was achieved by posterior fusion alone. However, in the present report, the tumor was very large, and there was no instability at the atlantoaxial segment. Therefore we managed the patient by resection of the mass through a high lateral cervical approach without fusion. The spinal cord symptoms diminished rapidly.     

Upper cervical spine surgery in rheumatoid arthritis: retrospective study of 30 patients followed for two years or more after Cotrel-Dubousset instrumentation

PURPOSE: To evaluate the efficacy of upper cervical spine surgery in symptomatic atlantoaxial instability due to rheumatoid arthritis (RA). MATERIAL AND METHODS: Thirty RA patients (29 women and one man) with a mean age of 56 years were studied retrospectively. Symptomatic forward slippage of the atlas on the axis with a synovial pannus surrounding the odontoid and magnetic resonance imaging evidence of spinal cord compression was present in all 30 patients; 18 patients had vertical translocation of the odontoid and 14 had basilar invagination. Surgery, performed between 1991 and 1997, consisted of occipitocervical fusion in 18 patients and atlantoaxial fusion in 12. Cotrel-Dubousset instrumentation was performed in all 30 patients. RESULTS: Mean follow-up was four and a half years. All patients were satisfied with the procedure and exhibited marked functional gains and objective neurological improvement (by one class in the Ranawat scheme). Stable fusion was documented in all 30 patients. CONCLUSION: Cervical instrumentation and bone grafting seems to provide functional and neurological gains in carefully selected RA patients with atlantoaxial instability and spinal cord compression. Long term follow-up suggests that the benefits are sustained and that morbidity is low.     

Transoral decompression, anterior plate fixation, and posterior wire fusion for irreducible atlantoaxial kyphosis in rheumatoid arthritis

STUDY DESIGN: Fifteen consecutive patients with irreducible atlantoaxial kyphosis caused by rheumatoid arthritis were treated by combined transoral odontoid resection, anterior plate fixation, and posterior wire fusion. OBJECTIVES: To investigate the clinical results of this new surgical procedure. SUMMARY AND BACKGROUND DATA: Irreducible atlantoaxial kyphosis in rheumatoid arthritis results from a destruction of the craniocervical joint ligaments and the anterior aspects of the lateral atlantoaxial joints. The development of a paradental synovial pannus and atlantoaxial joint impaction prevents reduction by conservative treatment, such as skull traction. Posterior surgical procedures for the treatment of the irreducible atlantoaxial kyphosis with spinal cord compression have been associated with high morbidity and mortality. METHODS: Fifteen consecutive patients were treated by transoral odontoid resection. The fixation was performed with anterior plating, according to the method of Harms in combination with posterior wire fusion according to Brooks. Before and after surgery, evaluation was performed using the parameters of pain (visual analog scale), range of motion, and subjective assessment of improvement and the Health Assessment Questionnaire. The neurologic deficit was defined according to the classifications proposed by Ranawat, Frankel, and Nurwick. Plain radiographs, including lateral flexion and extension views, and magnetic resonance scans were obtained. RESULTS: No perioperative fatality occurred. The average clinical and radiographic follow-up was 50.7 +/- 15.6 months (range, 26-77). Postoperative pain was relieved (mean pain score before surgery, 7.9 +/- 1.87; after surgery, 3.8 +/- 1.27), and the range of motion of all patients increased (mean 21.5 +/- 14.0 degrees for rotation; mean 17.2 +/- 5. 54 degrees for bending). The score on the Health Assessment Questionnaire increased in three patients, remained unchanged in three and decreased in six patients (three had died). All patients improved at least one Ranawat level after surgery, except a patient in Ranawat Class II, whose condition remained unchanged. All patients were satisfied with the procedure and reported subjective improvement. CONCLUSION: Transoral plate fixation combined with posterior wire fixation after transoral odontoid resectionis an effective, reliable, and safe procedure for the treatment of irreducible atlantoaxial kyphosis in rheumatoid arthritis.     

Retroodontoid mass without atlantoaxial subluxation in an elderly patient: case report

A Mass at the craniovertebral junction is relatively rare. We report a case of retroodontoid mass without atlantoaxial subluxation. An 84-year-old female presented to our hospital with paresthesia in the right upper and lower limb. She had no history of head or spine injury. Neurological examination revealed slight motor weakness of the right upper and lower limb. Cervical radiographs showed osteoarthrosis without atlantoaxial subluxation. MRI revealed retroodontoid, extra-dural mass that severely compressed the adjacent spinal cord. The patient underwent C1 laminectomy and posterior C1-C2 fusion with polyaxial screw and rod fixation. Simultaneously, the mass was resected partially. Histopathologically, the surgical specimen was a non-neoplastic fibrocartliginous mass and inflammatory cells were not seen. Postoperative course was uneventful and her neurological condition gradually improved. MRI revealed marked reduction of the mass and improvement of the spinal cord compression six months after the operation. We discuss the genesis of the retroodontoid mass and the strategy for surgical treatment.     

Retro-odontoid soft tissue mass associated with atlantoaxial subluxation in an elderly patient: a case report

BACKGROUND: We present the case of an elderly patient with a retro-odontoid soft tissue mass associated with atlanto-axial subluxation. CASE DESCRIPTION: A 74-year-old man was admitted to our hospital with progressive motor weakness in his right arm and neck pain. Radiological examinations revealed atlantoaxial subluxation and diffuse degenerative changes. Cervical MRI revealed a syrinx at the C1 level and a retro-odontoid soft tissue mass that severely compressed the spinal cord. The mass was of low signal intensity on both T1- and T2-weighted images. Conservative therapy could not stop the progression of his symptoms, so posterior decompression via a laminectomy of C1 and occipitocervical fixation was performed. These procedures resulted in an improvement of his neurological condition and in reduction of the mass and the compression of the spinal cord. CONCLUSION: The patient lacked any specific conditions that might have caused chronic atlantoaxial subluxation. The degenerative changes alone might have provoked chronic atlantoaxial subluxation and a subsequent retro-odontoid soft tissue mass. In patients with this condition, posterior fixation without direct removal of the mass should be the first choice for surgical intervention.     

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.     

Rheumatoid pannus presenting as a large epidural mass in the subaxial cervical spine: A case report

Rheumatoid arthritis (RA) is a debilitating inflammatory condition characterised by joint damage that affects the cervical spine most commonly at the atlantoaxial joint resulting in neck pain and myelopathy. The pathogenesis of RA involves the formation of a hyperplastic synovial tissue, termed pannus, which invades the local bone and causes osseous erosion. Here, we describe a case of rapid onset quadriparesis due to spinal cord compression at C5–C6 secondary to vertebral subluxation and mass effect from a large inflammatory pannus in the subaxial spine. Surgical decompression and resection of the subaxial pannus were performed, and the patient regained strength in all extremities. Histopathologic evaluation of the resected tissue confirmed the diagnosis of pannus over other more common epidural masses. Pannus formation commonly occurs in the peri-odontoid region; however, its presentation as a large soft tissue mass in the subaxial spine is not described in the current literature. Therefore, pannus should be considered in the differential diagnosis of epidural masses in the spine of RA patients. We use this case to discuss the pathology and radiological findings relevant to rheumatoid pannus formation in the subaxial cervical spine, as well as emphasise the importance of treatment in the context to severe degenerative disease.     

Cervifix在陈旧性寰枢椎脱位并高位颈髓压迫症中的应用

目的:探讨Cervifix内固定系统治疗陈旧性寰枢椎脱位并脊髓不全损伤的价值。方法:36例陈旧性寰枢椎脱位并脊髓不全损伤行后路融合、Cervifix内固定。男23例、女13例,年龄15～62岁,平均38.3岁。陈旧性外伤21例,先天性畸形9例,类风湿性关节炎伴寰椎前脱位6例。结果:随访8～42个月,平均19个月。术后脊髓功能按JOA17分法评定,改善率为71.4％。全部患者均获骨性融合,内置物无松动、断裂及脊髓损伤加重等并发症。结论:Cervifix内固定可提供坚强有效的节段性固定,提高融合率。同时,可预防单纯减压融合术后早期失稳导致的高位脊髓损伤加重。     

Axis治疗难复性寰枢椎脱位并脊髓不全损伤

目的：探讨Axis内固定系统治疗难复性寰枢椎脱位并脊髓不全损伤的应用价值。方法：29例难复性寰枢椎脱位并脊髓不全损伤行后路融合、Axis内固定。男16例，女13例，年龄18～60岁，平均39．2岁。其中外伤性19例，先天性畸形7例，类风湿性关节炎3例。结果：随访7～46个月，平均20个月。术后脊髓功能按JOA 17分法评定，改善率为78．6％。全部患者均获骨性融合，无脊髓损伤加重等并发症。结论：Axis内固定可提供立刻强有效的节段性固定，提高融合率，同时，可预防单纯减压融合术后早期失稳导致的高位脊髓损伤加重。