Upper thoracic myelopathy caused by vertebral collapse and subluxation in rheumatoid arthritis: report of two cases

We report two cases of rheumatoid arthritis (RA) with upper thoracic myelopathy and a review of the literature. Clinical data of a 47-year-old woman (case 1) and a 54-year-old woman (case 2) are described. Case 1 showed a transverse-type myelopathy at the T2 segment level of the spinal cord and case 2 had the same type of myelopathy at the T4 segment level. Case 1 had anterior vertebral subluxation of C7 due to marked vertebral collapse and Case 2 had subluxation of T2 with vertebral destruction. These two patients had the mutilating type of RA with multilevel spontaneous fusion in the cervical spine. The lesions in the thoracic spine might be caused by the severe destructive inflammation that is characteristic in mutilating disease. The vertebral collapse might lead to subluxation of the upper thoracic vertebra, resulting in spinal cord compression. Upper thoracic subluxation might be caused by vertebral collapse due to RA and the increased motion as a compensation for decreased mobility caused by spontaneous fusion in the cervical spine.     

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1–C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and non-rheumatoid patients. Contributing radiological factors to the subluxation have also not been evaluated. The objective of this study was to evaluate subaxial subluxation after atlantoaxial transarticular screw fixation in patients with and without RA and to find contributing factors. Forty-three patients who submitted to atlantoaxial transarticular screw fixation without any concomitant operation were followed up for more than 1 year. Subaxial subluxation and related radiological factors were evaluated by functional X-ray measurements. Statistical analyses showed that aggravations of subluxation of 2.5 mm or greater were more likely to occur in RA patients than in non-RA patients over an average of 4.2 years of follow-up, and postoperative subluxation occurred in the anterior direction in the upper cervical spine. X-ray evaluations revealed that such patients had a significantly smaller postoperative C2–C7 angle, and that the postoperative AA angle correlated negatively with this. Furthermore, anterior subluxation aggravation was significantly correlated with the perioperative atlantoaxial and C2–C7 angle changes, and these two changes were strongly correlated to each other. In conclusion, after atlantoaxial transarticular screw fixation, rheumatoid patients have a greater risk of developing subaxial subluxations. The increase of the atlantoaxial angel at the operation can lead to a decrease in the C2–C7 angle, followed by anterior subluxation of the upper cervical spine and possibly neurological deterioration.     

Rheumatoid Arthritis of the Cervical Spine

Cervical involvement in patients with rheumatoid arthritis occurs primarily in the upper cervical spine. The characteristic deformities are atlantoaxial subluxation, vertical settling, and subaxial subluxation. The typical patient complaints are neck pain and occipital pain. Subtle signs of myelopathy may also be present. Useful radiologic studies include plain radiography, tomography, and functional magnetic resonance imaging. The most helpful radiographic measurements are the anterior atlantodens interval, the posterior atlantodens interval, and assessment of vertical settling. Atlantoaxial subluxation greater than 9 mm with vertical settling and a posterior atlantodens interval less than 14 mm correlate with neurologic deficit. Nonoperative management does not change the natural history of cervical disease. Traditional surgical indications include intractable pain and neurologic deficit. The author discusses more controversial indications and proposes a rationale and protocol for treatment. The primary surgical objectives are to achieve stabilization of the affected segments and to relieve neural compression by reduction of subluxations or direct decompression. Arthrodesis provides reliable pain relief. Neurologic recovery occurs more consistently in patients with lower grades of preoperative myelopathy.     

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。     

Chronic cephalalgia as a sequela of rheumatic spondylarthritis of the cervical spine

Deformity and instability of the cervical spine is quite frequently recordable from patients with chronic rheumatoid arthritis. More than 70 per cent of patients who had been suffering this rheumatoid disease for more than ten years with mutilating peripheral joint lesions exhibited radiologically visible and clinically recordable cervical spine disorders. Anterior atlanto-axial subluxation has proved to be the most common rheumatic deformity of the cervical spine and was found to cause severe, even intolerable occipito-cervical headache. The authors have obtained good results from posterior C1-C2 fusion operation on patients in whom headache had been invalidising and resistant to conservative treatment.     

Occipitocervical stabilization for myelopathy in patients with rheumatoid arthritis. Implications of not bone-grafting

BACKGROUND: Approximately 0.9 percent of the white adult population of the United States and 1.1 percent of the adult population in Europe are affected by seropositive rheumatoid arthritis. As many as 10 percent of those patients may need an operation for atlantoaxial subluxation. Severe instability, especially when associated with vertical subluxation of the odontoid process, can result in progressive cervical myelopathy. Typically, occipitocervical fixation has been performed for these patients with use of autograft bone to achieve long-term stability through a solid fusion. Harvesting the bone graft increases the operative risk to the patient and may result in increased morbidity. In our experience, patients who have had no clear radiographic evidence of fusion following use of occipitocervical instrumentation seemed to have done as well as those who have had obvious fusion. One assumption is that the clinical improvement might be attributable simply to stabilization of the joint rather than to osseous fusion. A longitudinal study was performed on patients with rheumatoid arthritis who required an operation because of craniocervical or upper cervical instability. METHODS: The results of clinical, radiographic, functional, and self-evaluations were studied to determine the efficacy of treatment and to compare the outcomes of bone-grafting with those of procedures done without bone-grafting in a group of 150 patients who underwent posterior occipitocervical stabilization with use of a contoured metal implant (a Ransford loop) that was affixed by sublaminar wires. Internal fixation was performed in 120 patients without bone-grafting and in thirty patients with use of autogenous bone-grafting. Preoperatively, 23 percent (thirty-five) of the 150 patients had mild neurological involvement (class II, according to the system of Ranawat et al.), 45 percent (sixty-eight) had objective findings of weakness and long-tract signs but were able to walk (class III-A), and 29 percent (forty-three) were quadriparetic and unable to walk (class III-B). The age of the patients at the time of the operation ranged from twelve to eighty-three years (mean, sixty-two years). RESULTS: There were significant improvements in postoperative Ranawat classes at all time-periods (range, p < 0.00005 to p = 0.0066) and in patient ratings of neck pain (range, p < 0.00005 to p = 0.0044) compared with preoperative scores. With the numbers available, there were no significant differences between the patients managed with a graft and those managed without grafting with respect to survival after the operation, Ranawat class, head or neck-pain rating, presence of subaxial abnormalities, radiographic craniovertebral motion, or vertical subluxation. Overall mortality at one month was 10 percent (fifteen of 150), although this value varied directly with the degree of preoperative disability. A second cervical spine operation was required in 11 percent (sixteen) of the 150 patients. CONCLUSIONS: While patients who have rheumatoid disease with anterior atlantoaxial subluxation should be treated with posterior atlantoaxial arthrodesis with use of bone-grafting and internal fixation, we believe that those who present with vertical instability and multi-level involvement can be treated with posterior occipitocervical stabilization with use of a contoured occipitocervical loop and sublaminar wire fixation without bone-grafting. Furthermore, we believe that the use of preoperative traction, bone cement, or a postoperative halo vest is unnecessary. Avoiding the harvesting of autogenous bone for grafting reduced the morbidity of this operation without compromising the outcome in these already sick patients.     

Biomechanical rationale for the pathology of rheumatoid arthritis in the craniovertebral junction

STUDY DESIGN: A finite-element model of the craniovertebral junction was developed and used to determine whether a biomechanical mechanism, in addition to inflammatory synovitis, is involved in the progression of rheumatoid arthritis in this region of the spine. OBJECTIVES: To determine specific structure involvement during the progression of rheumatoid arthritis and to evaluate these structures in terms of their effect on clinically observed erosive changes associated with the disease by assessing changes in loading patterns and degree of anterior atlantoaxial subluxation. SUMMARY OF BACKGROUND DATA: Rheumatoid arthritis involvement of the occipito-atlantoaxial (C0-C1-C2) complex is commonly seen. However, the biomechanical contribution to the development and progression of the disease is neither well understood nor quantified. Although previous cadaver studies have elucidated information on kinematic motion and fusion techniques, the modeling of progressive disease states is not easily accomplished using these methods. The finite-element method is well suited for studying progressive disease states caused by the gradual changes in material properties that can be modeled. METHODS: A ligamentous, nonlinear, sliding-contact, three-dimensional finite-element model of the C0-C1-C2 complex was generated from 0.5 mm thick serial computed tomography scans. Validation of the model was accomplished by comparing baseline kinematic predictions with experimental data. Transverse, alar, and capsular ligament stiffness were reduced sequentially by 50%, 75%, and 100% (removal) of their intact values. All models were subjected to flexion moments replicating the clinical diagnosis of rheumatoid arthritis using full flexion lateral plane radiographs. Stress profiles at the transverse ligament-odontoid process junction were monitored. Changes in loading profiles through the C0-C1 and C1-C2 lateral articulations and their associated capsular ligaments were calculated. Anterior and posterior atlantodental interval values were calculated to correlate ligamentous destruction with advancement of atlantoaxial subluxation. RESULTS: Model predictions (at 0.3 Nm) fell within one standard deviation of experimental means, and range of motion data agreed with published in vitro and in vivo values. The model predicted that stresses at the posterior base of the odontoid process were greatly reduced with transverse ligament compromise beyond 75%. Decreases through the lateral C0-C1 and C1-C2 articulations were compensated by their capsular ligaments. Anterior and posterior atlantodental interval values indicate that the transverse ligament stiffness decreases beyond 75% had the greatest effect on atlantoaxial subluxation during the early stages of the disease (no alar and capsular ligament damage). Subsequent involvement of the alar and capsular ligaments produced advanced atlantoaxial subluxation, for which surgical intervention may be warranted. CONCLUSIONS: To the best of the authors' knowledge, this is the first report of a validated, three-dimensional model of the C0-C1-C2 complex with application to rheumatoid arthritis. The data indicate that there may be a mechanical component (in addition to enzymatic degradation) associated with the osseous resorption observed during rheumatoid arthritis. Specifically, erosion of the odontoid base may involve Wolff's law of unloading considerations. Changes through the lateral aspects of the atlas suggest that this same mechanism may be partially responsible for the erosive changes seen during progressive rheumatoid arthritis. Anterior and posterior atlantodental interval values indicate that complete destruction of the transverse ligament coupled with alar and/or capsular ligament compromise is requisite if advanced levels of atlantoaxial subluxation are present.     

Results of a longer than 10-year follow-Up of patients with rheumatoid arthritis treated by occipitocervical fusion

STUDY DESIGN: Evaluation of results a longer than 10-year follow-up of patients with upper cervical lesions due to rheumatoid arthritis who underwent occipitocervical fusion. OBJECTIVE: To determine the final outcome of patients with upper cervical lesions due to rheumatoid arthritis treated by occipitocervical fusion. SUMMARY OF BACKGROUND DATA: There are few studies reporting the final outcome of patients with rheumatoid arthritis treated by occipitocervical fusion and observed for longer than 10 years. METHODS: The subjects were 16 patients with rheumatoid arthritis with myelopathy who underwent occipitocervical fusion with a rectangular rod more than 10 years ago. All 16 patients had irreducible atlantoaxial dislocation, and 11 also had vertical dislocation of the axis. All patients had preoperative nuchal pain, and were classified into Class II (two patients), Class IIIA (nine patients), and class IIIB (five patients) according to Ranawat's preoperative neurologic classification. RESULTS: The atlas-dens interval remained the same as immediately after surgery. Vertical dislocation returned to the preoperative condition, despite successful surgical correction. Preoperative occipital pain disappeared or was reduced in all cases. Myelopathy improved in 12 of the 16 patients (75%) by more than one class in the Ranawat preoperative neurologic classification. Survival rate at 10 years after surgery was 38%; mean age at death was 70.7 years. The postoperative periods during which patients could walk by themselves ranged from 6 months to 13 years (mean, 7.5 years). CONCLUSIONS: Occipitocervical fusion for patients with rheumatoid arthritis is useful for decreasing nuchal pain, reducing myelopathy, and improving prognosis.     

The cervical spine in juvenile chronic arthritis.

BACKGROUND CONTEXT: In patients with juvenile chronic arthritis (JCA) the cervical spine is often affected, leading to pain and functional limitations. PURPOSE: To describe the frequency of the radiographic abnormalities in the cervical spine of a large series of patients with JCA, examined after skeletal maturity. STUDY DESIGN: Consecutive patients with JCA, who had cervical spine radiographs available taken at adult age (>18 years) were included in the study from one outpatient clinic and one rheumatology ward in the Rheumatism Foundation Hospital, Heinola, Finland. PATIENT SAMPLE: The series consisted of 159 patients fulfilling the diagnostic criteria of the European League Against Rheumatism for JCA. OUTCOME MEASURES: Evaluation of cervical spine radiographs for inflammatory changes. METHODS: Inflammatory changes in the cervical spine radiographs were measured as well as the size of the fourth cervical vertebra. Patient records were studied. The statistical analysis was calculated by Student's t-test or Mann-Whitney U test. RESULTS: In 98 cases (62%) some inflammatory changes were detected in the cervical spine. Apophyseal joint ankylosis was noted in 65 patients (41%), anterior atlantoaxial subluxation in 27 (17 %) and atlantoaxial impaction in 39 (25 %). The fourth cervical vertebra was abnormally small in 41 patients (26%). CONCLUSIONS: Radiographically, the most frequent inflammatory change in the cervical spine of patients with JCA was apophyseal joint ankylosis at multiple levels. Atlantoaxial impaction and anterior atlantoaxial subluxation were typical of the upper cervical spine. Clinically, these changes tend to limit neck movements. A small C4 vertebral body was seen in patients with early disease onset and short body stature.     

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.     

Atlantoaxial subluxation in different intraoperative head positions in patients with rheumatoid arthritis

BACKGROUND: Disorders of the cervical spine are often observed in patients with rheumatoid arthritis (RA). However, the best head position for RA patients with atlantoaxial subluxation in the perioperative period is unknown. This study investigated head position during general anesthesia for the patients with RA and proven atlantoaxial subluxation. METHODS: During anesthesia of patients with RA and proven atlantoaxial subluxation, the authors used fluoroscopy to obtain a lateral view of the upper cervical spine in four different positions: the mask position, the intubation position, the flat pillow position, and the protrusion position. Copies of the still fluoroscopic images were used to determine the anterior atlantodental interval, the posterior atlantodental interval, and the angle of atlas and axis (C1-C2 angle). RESULTS: The anterior atlantodental interval was significantly smaller in the protrusion position (2.3 mm) than in the flat pillow position (5.1 mm) (P < 0.05). The posterior atlantodental interval was significantly greater in the protrusion position (18.9 mm) than in the flat pillow position (16.2 mm) (P < 0.05). The C1-C2 angle was, on average, 9.3 degrees greater in the protrusion position than in the flat pillow position (P < 0.05). CONCLUSION: This study showed that the protrusion position using a flat pillow and a donut-shaped pillow during general anesthesia reduced the anterior atlantodental interval and increased the posterior atlantodental interval in RA patients with atlantoaxial subluxation. This suggests that the protrusion position, which involves support of the upper cervical spine and extension at the craniocervical junction, might be advantageous for these patients.     

Atlantoaxial subluxation in Reiter's syndrome. A report of three cases and review of the literature

Three patients with the unusual manifestation of atlantoaxial subluxation in Reiter's syndrome are studied. Each patient had mild symptoms referable to the cervical spine and radiologic evidence of erosive disease elsewhere in the skeleton. One patient had an 11-year history of Reiter's syndrome when the atlantoaxial subluxation was detected. The other two had atlantoaxial subluxation detected within 1 year of initial presentation, at variance with three other such patients that were reported previously, in whom there was a 6- to 10-year interval from initial presentation until radiographic documentation of atlantoaxial subluxation. Cervical spine radiographs, including flexion and extension views, are recommended for all patients with Reiter's syndrome and cervical spine symptoms.     

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。     

膝,髋类风湿关节炎与颈椎的相关病变

了解类风湿关节炎患者在接受全膝,全髋关节置换术时颈椎受累情况。方法通过对４６例接受全膝,全髋置换术的类风湿关节炎患者的颈椎Ｘ线片的测量,了解寰枢椎的前后半脱位,垂直半和下位颈椎半脱位的发生情况,以及手术时有无颈部症状的主诉,神经学检查是否异常等进行回顾性调查。     

The prevalence of cervical spondylolisthesis.

This study assessed the prevalence of cervical spondylolisthesis in patients undergoing radiographic studies for reasons unrelated to their cervical spine. Scout lateral cervical spine radiographs of 174 patients who had barium swallows were reviewed for the degree and level of cervical spondylolisthesis. Nine patients were found to have >2 mm of anterior subluxation of the cervical spine for a prevalence of 5.2%. Two patients had involvement at the C2-C3 level, one patient at C3-C4, four patients at C4-C5, one patient at C5-C6, and one patient at C7-T1. Subluxation ranged from 2 to 4 mm. Posterior subluxation (retrolisthesis) was not found in any patient. None of the nine patients with spondylolisthesis had complaints of neck pain or upper extremity symptoms, and none had a history of rheumatoid arthritis or cervical trauma.     

Outcome of surgery for rheumatoid cervical spine at one institute over three decades

Background contextSurgical intervention is a therapeutic choice for atlantoaxial subluxation (AAS), vertical subluxation (VS), and subaxial subluxation (SAS) associated with rheumatoid cervical spine. However, the long-term outcomes of different subgroups remain unclear, although rheumatoid arthritis (RA) is a progressive disease even after surgery.PurposeTo evaluate the outcomes of surgery for various subgroups of rheumatoid cervical spine, performed at a single institute over three decades.Study designRetrospective clinical analysis.Patient sampleOne-hundred eighteen seropositive RA patients treated at one institute over the past three decades. Atlantoaxial fixation was performed in 28 AAS patients. Occipitospinal fusion was performed in 41 irreducible AAS or VS patients. Laminotomy with autologous bone fusion was performed in 22 patients, anterior fusion in 5, laminoplasty in 4, and posterior decompression/fusion with instrumentation in 12 with SAS.MethodsClinical outcomes using the Japanese Orthopedic Association score, complications, deterioration of RA, and mortality rate during the follow-up were investigated from preoperation to more than 10 years after surgery in the subgroups.Outcome measuresOutcomes were compared among the subgroups.ResultsPatients with AAS exhibited significantly better clinical outcomes throughout the follow-up period compared with patients from the other subgroups. Patients with SAS had the worst neurologic status even at preoperation, and the symptomatic improvement achieved by surgery deteriorated within less than 5 years. Deterioration of outcome was caused by occurrence of complications and deterioration of RA during the follow-up. The mortality rates at 5 and 10 years after surgery were 20% and 33%, respectively.ConclusionsThe outcome of surgery for rheumatoid cervical spine was different in the various subgroups and associated with the occurrence of complications and deterioration of RA.     

Atlantoaxial Subluxation in Different Intraoperative Head Positions in Patients with Rheumatoid Arthritis

Background: Disorders of the cervical spine are often observed in patients with rheumatoid arthritis (RA). However, the best head position for RA patients with atlantoaxial subluxation in the perioperative period is unknown. This study investigated head position during general anesthesia for the patients with RA and proven atlantoaxial subluxation.

Methods: During anesthesia of patients with RA and proven atlantoaxial subluxation, the authors used fluoroscopy to obtain a lateral view of the upper cervical spine in four different positions: the mask position, the intubation position, the flat pillow position, and the protrusion position. Copies of the still fluoroscopic images were used to determine the anterior atlantodental interval, the posterior atlantodental interval, and the angle of atlas and axis (C1-C2 angle).

Results: The anterior atlantodental interval was significantly smaller in the protrusion position (2.3 mm) than in the flat pillow position (5.1 mm) (P < 0.05). The posterior atlantodental interval was significantly greater in the protrusion position (18.9 mm) than in the flat pillow position (16.2 mm) (P < 0.05). The C1-C2 angle was, on average, 9.3[degrees] greater in the protrusion position than in the flat pillow position (P < 0.05).     

Rheumatoid cervical joint disease — a challenge to the anaesthetist

Cervical joint disease in rheumatoid arthritis patients is common. These patients may be at risk for severe life-threatening neurological problems in the perioperative period and thus present’ a challenge to the anaesthetist. By understanding the various anatomical abnormalities that may occur in rheumatoid cervical joint disease, the anaesthetist can design an appropriate management plan for the patient. The destruction of normal anatomy by rheumatoid arthritis can result in atlanto-axial subluxation (AAS) or subaxial subluxation. The atlanto-axial subluxation is further divided anatomically into anterior AAS, posterior AAS, vertical AAS, and lateral/rotatory AAS. In addition to the history and physical examination of the rheumatoid arthritis patient, radiological evaluation of the cervical spine is highly recommended. With the identification of the specific anatomical lesion the anaesthetist can predict and avoid movements which may lead to, or worsen, neurological problems. In the event of an emergency where full evaluation of the cervical spine is not possible the anaesthetist must presume that the rheumatoid patient has severe cervical spine instability and use the most cautious approach.     

Spontaneous regression of periodontoid pannus mass in psoriatic atlantoaxial subluxation. Case report

STUDY DESIGN: A case report of a 41-year-old man with psoriasis who had cervical myelopathy caused by atlantoaxial subluxation and periodontoid pannus mass. OBJECTIVE: To describe the possible mechanism underlying the periodontoid pannus formation and the optimal treatment for such cases. SUMMARY OF BACKGROUND DATA: Atlantoaxial subluxation causing spinal cord compression at the craniocervical junction may develop in patients with rheumatoid or psoriatic arthritis. Periodontoid pannus formation plays an important role in compromising the anteroposterior diameter of the spinal canal and in causing neurologic deficits. Transoral transpharyngeal excision of the pannus is sometimes thought necessary for anterior decompression of the spinal cord. Spontaneous resolution of the periodontoid pannus after posterior atlantoaxial fusion and fixation has been documented in rheumatoid arthritis, but not in psoriatic arthritis. METHODS: The patient underwent posterior atlantoaxial fusion and Halifax fixation. RESULTS: The patient experienced clinical improvement. Regression of the periodontoid pannus mass was observed on magnetic resonance imaging. CONCLUSIONS: Posterior fusion and instrumentation resulted in spontaneous regression of the pannus mass and symptomatic relief. This report provides evidence that atlantoaxial instability may be the sine qua non for the formation of periodontoid pannus, and that amelioration of such instability leads to spontaneous resolution of the pannus mass.     

Effect of biological agents on cervical spine lesions in rheumatoid arthritis

STUDY DESIGN.: A retrospective cohort analysis. OBJECTIVE.: To determine the effect of biological agents (BAs) on the development and progression of cervical spine lesions and identify predictors of lesion progression. SUMMARY OF BACKGROUND DATA.: The introduction of BAs has facilitated advances in the treatment of rheumatoid arthritis (RA). BAs reduce disease activity and limit structural joint damage. However, the effect of BAs on cervical spine lesions remains unclear. METHODS.: Thirty-eight subjects who received more than 2 years of continuous BA treatment were enrolled. The mean x-ray interval was 4.4 years. RA activity was evaluated by disease activity score (DAS)-C reactive protein (CRP) and matrix metalloproteinase (MMP)-3. Radiographical definitions of cervical lesions were atlanto-dental interval (ADI) more than 3 mm for atlanto-axial subluxation (AAS), Ranawat value less than 13 mm for vertical subluxation (VS), and anterior or posterior listhesis more than 2 mm for subaxial subluxation (SS). Definitions of radiographical progression were an increase of ADI more than 2 mm for AAS, a decrease of both Ranawat and Redlund-Johnell values more than 2 mm for VS, and an increase of listhesis more than 2 mm for SS. RESULTS.: RA activity responded dramatically to BA therapy (DAS-CRP from 4.3 to 2.3, P < 0.01; MMP-3 from 207.9 ng/mL to 105.6 ng/mL, P < 0.01). Baseline radiographical evaluation showed no pre-existing cervical spine lesions in 12 cases, AAS in 15 cases, and VS in 11 cases. Radiological progression was found in 1 (8%) patient in the no lesion group, 12 patients (80%) in the AAS group, and 9 patients (80%) in the VS group. The incidence of progression was significantly lower in the no lesion group compared with the other groups. Multivariate regression analysis showed that the presence of pre-existing cervical lesions was the single greatest predictor of progression. CONCLUSION.: BAs prevented the development of de novo cervical spine lesions in patients with RA, but failed to inhibit progression of pre-existing RA lesions.