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.     

Rheumatoid arthritis in the cervical spine

The cervical spine often becomes involved early in the course of rheumatoid arthritis, leading to three different patterns of instability: atlantoaxial subluxation, atlantoaxial impaction, and subaxial subluxation. Although radiographic changes are common, the prevalence of neurologic injury is relatively low. The primary goal of treatment is to prevent permanent neurologic injury while avoiding potentially dangerous and unnecessary surgery. Strategies include patient education, lifestyle modification, regular radiographic follow-up, and early surgical intervention, when indicated. Magnetic resonance imaging is indicated when neurologic deficit (myelopathy) occurs or when plain radiographs show atlantoaxial subluxation with a posterior atlantodental interval < or =14 mm, any degree of atlantoaxial impaction, or subaxial stenosis with a canal diameter < or =14 mm. Surgery should be considered promptly for any of the following: progressive neurologic deficit, chronic neck pain in the setting of radiographic instability that does not respond to nonnarcotic pain medication, any degree of atlantoaxial impaction or cord stenosis, a posterior atlantodental interval < or =14 mm, atlantoaxial impaction represented by odontoid migration > or =5 mm rostral to McGregor's line, sagittal canal diameter <14 mm, or a cervicomedullary angle <135 degrees.     

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。     

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.     

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.     

Predictors of paralysis in the rheumatoid cervical spine in patients undergoing total joint arthroplasty

BACKGROUND: Rheumatoid arthritis is sometimes associated with radiographic evidence of instability of the cervical spine, most commonly an abnormal subluxation between vertebrae. When this instability compromises the space that is available for the spinal cord, it may be predictive of paralysis. However, the prevalence of radiographic signs of instability that are predictive of paralysis among patients with nonspinal orthopaedic manifestations of rheumatoid arthritis is unknown. METHODS: Radiographs of the cervical spine of patients with rheumatoid arthritis who had undergone total joint arthroplasty over a five-year period were retrospectively reviewed. The radiographs were evaluated for predictors of paralysis (a posterior atlantodental interval of <14 mm or a subaxial space available for the cord measuring <14 mm) and were compared with traditional parameters of instability (an anterior atlantodental interval of >3 mm or subaxial subluxation of >3 mm). RESULTS: Forty-nine of the sixty-five patients who were identified had flexion and extension lateral radiographs available for review. Only one of these patients had a posterior atlantodental interval of <14 mm, and only three had a space available for the cord that measured <14 mm at one level or more. In comparison, twenty patients had radiographic evidence of instability on the basis of traditional parameters. CONCLUSIONS: Although nearly one-half of the patients in the present study had radiographic evidence of cervical instability on the basis of traditional measurements, only four patients (8%) had a radiographic finding that was predictive of paralysis. Thus, while radiographic evidence of cervical instability was not infrequent in this population of patients who underwent total joint arthroplasty for rheumatoid arthritis, radiographic predictors of paralysis were much less common.     

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.     

Predictors of aggravation of cervical spine instability in rheumatoid arthritis patients: the large joint index

Background

Improved rheumatic drugs have provided significant benefits, but activities of daily living are not improved if spinal symptoms are overlooked. Furthermore, the appropriate timing for examining the cervical spine during follow-up is unclear.

Methods

To evaluate the relations of cervical spine instabilities and an index for cervical spine lesion in rheumatoid arthritis (RA) based on extremity radiographs, we examined preoperative radiographs of 100 RA patients who underwent total knee arthroplasty. Radiographic results for eight large joints (bilateral shoulders, elbows, hips, and knees) were graded as follows: Larsen grade ≥2 for each joint was scored as 1 point, which we refer to as the “large joint index” (LJI), based on 0–8 points. The associations of radiographic cervical lesions with LJI, Ranawat class, the disease duration, RA drugs, or blood analysis data were evaluated.

Results

Atlantoaxial subluxation (AAS) (≥5 mm) was found in 45 patients, vertical subluxation (VS) (≤13 mm) in 42, a posterior atlantodental interval (PADI) (<14 mm) in 21, and subaxial subluxation (SAS) (≥3 mm) in 23. Most patients with a PADI < 14 mm (19/21, 90%) were complicated with both AAS and VS. LJI had a significant association with AAS (P < 0.0001), VS (P < 0.01), and PADI (P < 0.01). The PADI was significantly lower (P < 0.0001) and the LJI was significantly higher (P < 0.01) in patients of Ranawat class II compared to patients of Ranawat class I. The disease duration, age at surgery, and age at onset were also significantly associated with cervical instabilities.

Conclusions

PADI should be recognized as a predictor of paralysis with anteroposterior instability and vertical and middle-low cervical spine instability. The LJI proposed in this study has the possibility of being a predictor of cervical lesions. Patients with RA onset at a young age and a long disease duration also have a risk of progression of cervical spine instability.     

Timing of cervical spine stabilisation and outcome in patients with rheumatoid arthritis

One complication of rheumatoid arthritis (RA) is the involvement of the cervical spine (CS). Although prophylactic stabilisation is recommended, the timing at which this should occur is poorly defined. The aim of our study was to evaluate the course of neurological symptoms in terms of the timing of surgery. A total of 34 patients with RA and CS involvement were surgically stabilised. These patients were classified using the Ranawat (RW) score both preoperatively and at an average of 54 months post-operatively. For each patient, the presence of atlantoaxial and subaxial subluxation as well as vertical migration of the odontoid was recorded. The anterior atlantodental interval was also assessed pre- and post-operatively. Improvement was obtained in 20 patients, the clinical situation remained unchanged in three patients and three patients manifested disease progression. In terms of the RW score, the 16 patients with pre-operative RW grades I-II showed no deterioration at the post-operative follow-up, with 13 of these patients showing an improvement; the 12 patients with pre-operative RW grades IIIA-IIIB did not show any improvement of neurological symptoms at follow-up, although seven of these patients subjectively assessed the symptoms to be less severe after surgery; three other patients showed a worsening of symptoms. Our results suggest that preventive stabilisation of CS in RA leads to acceptable results, although the complications of the surgery are obvious. However, early operative treatment may delay the detrimental course of cervical myelopathy in RA.     

Headmaster collar restricts rheumatoid atlantoaxial subluxation

STUDY DESIGN: A radiographic study of the effect of a modern orthotic device in the treatment of rheumatoid atlantoaxial subluxation. OBJECTIVE: To study the ability of a new open-type collar to restrict atlantoaxial subluxation. SUMMARY OF BACKGROUND DATA: Atlantoaxial subluxation is common in rheumatoid arthritis, and thus, the development of conservative treatments is important. It has been shown that a custom-made stiff collar significantly restricts atlantoaxial subluxation in approximately half of patients with unstable atlantoaxial subluxation. METHODS: In 30 successive patients with rheumatoid atlantoaxial subluxation, lateral view radiographs were taken in flexion, extension, and neutral positions without a collar and in flexion with the Headmaster collar. RESULTS: The mean atlantoaxial distance during flexion was 7.1 +/- 1.8 mm and during extension was 1.0 +/- 1.0 mm, and the mean instability was 6.1 +/- 2.3 mm. In the 20 cases with the greatest stabilizing effect, the mean atlantoaxial distance during flexion with a collar was 1.1 +/- 1.3 mm, whereas in 10 patients with lesser effect it was 6.7 +/- 2.5 mm (P < 0.0001). The lesser stabilizing effect was associated with the presence of atlantoaxial subluxation in the neutral position. CONCLUSION: The Headmaster collar is an effective and useful tool in the conservative treatment of simple unstable atlantoaxial subluxation, but an ordinary custom-made stiff collar is still often needed. These two collars are complementary, and their selection and use must be determined individually.     

Prevalence of cervical spine instability among Rheumatoid Arthritis patients in South Iraq

Aim of the workThis study analysed the prevalence of cervical spine instability in Rheumatoid Arthritis (RA) patients following at a single centre in Basrah.Patients and methodsData were collected directly from patients through cervical spine examinations. Each patient was sent for dynamic (flexion and extension) lateral cervical radiographic imaging to assess the presence of atlantoaxial subluxation (AAS), superior migration of the odontoid (SMO) and sub-axial subluxation (SAS). Patients with positive radiographic findings were sent for MRI scans of the cervical spine to assess neurological compression.ResultsThe prevalence rate of cervical spine instability in RA was 15/203 (7.4%) of the total sample, occurring primarily in patients of 37–65 years old (mean: 48 ± 8.9 years), were 3/15 (20%) aymptomatic. The majority (60%) being at the moderate stage of the disease activity (using a Clinical Disease Activity Index [CDAI). In terms of type of cervical spine involvement, isolated AAS was found to have the highest occurrence (73.3%), followed by combined SAS and SMO (13.3%), combined AAS and SMO (6.7%), and combined AAS and SAS (6.7%). A significant relationship was found between the type of cervical spine involvement in RA and a disease onset duration, disease activity, body mass index and peripheral erosion with P value < 0.05.ConclusionCervical spine subluxation in RA patients may be asymptomatic It is therefore essential to obtain a dynamic radiographic image of the cervical spine in order to diagnose cervical spine involvement and protect the patient from severe outcomes.The clinical trial registration number included in a the official document from Ministry of Higher Education and Science Research/Basrah University/Faculty of Medicine to Basrah Health Directorate/Research and Development Division is 72/3588 in 7 Jan 2017.     

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.     

寰枢椎椎弓根螺钉内固定术治疗儿童寰枢椎脱位的初步报告

目的:探讨寰枢椎椎弓根螺钉内固定手术治疗儿童寰枢椎脱位的可操作性和近期疗效。方法:2005年9月~2011年3月对16例儿童寰枢椎脱位患者采用寰枢椎椎弓根螺钉内固定术治疗,男9例,女7例;年龄5～13岁,平均9.1岁。均有枕颈部疼痛、颈部僵硬;3例有高位颈脊髓病表现,ASIA分级:D级2例,C级1例。术前均行颈椎正侧位及过伸过屈位X线片、CT和MRI检查,均诊断为寰枢椎脱位,其中寰椎横韧带断裂1例,寰枢椎骨折脱位1例,先天性齿状突畸形12例,寰枢椎固定旋转半脱位2例;颈脊髓受压5例。寰椎后弓(椎弓根)高度2.5~3.8mm,平均3.0mm;寰齿前间隙6~14mm,平均9mm。术前常规行牵引1~2周复位,完全复位7例,部分复位5例,不能复位4例。术中采用"寰椎椎弓根显露置钉法",在直视下行C1、C2置钉,复位固定,植骨融合。随访患者症状和神经功能改善情况,定期行颈椎X线片及CT复查,了解内固定及植骨融合情况。结果:16例均行双侧寰枢椎椎弓根螺钉内固定,手术过程顺利,64枚螺钉均成功置入,复位固定满意,无术中、术后神经和血管并发症。术中出血150~650ml,平均300ml;手术时间100~190min,平均130min。12例随访12~72个月,平均28.5个月,术后3~6个月寰枢椎均骨性融合;末次随访时,颈枕症状明显改善,3例术前有脊髓功能损害者均好转,2例术前ASIA分级D级者恢复到E级,1例术前ASIA分级C级者恢复到D级;未发现螺钉松动、断钉和寰枢椎再移位现象,未发现曲轴现象。结论:采用"寰椎椎弓根显露置钉法"行寰椎椎弓根螺钉内固定可操作性强,置钉安全性高;寰枢椎椎弓根螺钉内固定治疗儿童寰枢椎脱位的近期疗效满意。     

Sagittal alignment of the subaxial cervical spine after C1-C2 transarticular screw fixation in rheumatoid arthritis

Several articles reported the association between the development of subaxial kyphosis and the hyperlordotic fixation of C1-C2. However, their patients were heterogeneous in both primary disease and operative procedure. Transarticular screw fixation has become a popular procedure for C1-C2 arthrodesis instead of wiring techniques in which C1-C2 is difficult to fix in the intended alignment. Furthermore, in rheumatoid arthritis (RA) patients, subaxial lesions play an important role in potential subaxial alignment changes. The subaxial influences after C1-C2 transarticular screw fixation in patients with RA are unclear. To investigate the radiographic features of the subaxial cervical spine after C1-C2 transarticular screw fixation for RA, we reviewed 28 cases of C1-C2 transarticular screw fixation for rheumatoid atlanto-axial subluxation. The sagittal alignment of C1-C2 and the subaxial cervical spine was measured and the factors that affect subaxial alignment were investigated. Subaxial alignment became less lordotic in the postoperative course. The C1-C2 fixation angle and subaxial alignment showed a negative linear correlation. However, no significant correlation was found between changes in the C1-C2 angle and changes in the subaxial alignment. Four patients had a postoperative kyphotic subaxial deformity. Neurologic deterioration recurred in 4 patients, because of the postoperative development of subaxial subluxation. Common radiographic changes included an increase in C1-C2 lordosis, constant inclination of C1, an anterior shift of C2, and a decrease in C2-C7 lordosis. Many factors, not only C1-C2 angle, are associated with subaxial sagittal alignment change after C1-C2 transarticular screw fixation.     

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.     

寰枢椎后路融合角度与下位颈椎曲度的相关性研究

目的 评价寰枢椎后路融合角度与术后下位颈椎矢状面曲度之间的联系并确定最佳的寰枢椎固定角度以保护颈椎生理曲度.方法 对1995年2月至2005年6月因寰枢椎脱位而行后路C1,C2融合术的92例患者进行术后随访.术前测量颈椎侧位片C1-C2,C2-C7夹角,并且进行术后长期随访,以观察术后随访C1-C2,C2-C7夹角之间的相关性. 结果所有患者均获得随访,时间2.0～10.3年,平均5.2年.术前及术后随访时C1-C2夹角平均值分别为18.4°±9.3°、26.0°±6.8°,差异有统计学意义(t=10.4,P<0.05);术前及术后随访时C2-C7夹角平均值分别为14.5°±10.1°、5.6°±12.0°,差异有统计学意义(t=6.0,P<0.05);其中术后随访C1-C2固定角度<20°(10°～20°)共计30例,≥20°(20.0°～43.6°)共计62例.C1-C2固定角度<20°者,术后随访C1-C2角度与C2-C7夹角之间无明确的相关性;C1-C2固定角度≥20°者,术后随访C1-C2角度与C2-C7夹角之间存在线性负相关;C1-C2术前、术后随访夹角的变化值与C2-C7术前、术后随访夹角的变化值之间也存在线性负相关. 结论寰枢关节行后路手术固定于高度前凸位时将导致术后下位颈椎的脊柱后凸,并且固定角度越大,下位颈椎的后凸程度就越大;为了保持下位颈椎的生理性曲度,手术中应尽量将C1-C2固定的角度控制在10°～20吨围内.     

牵引治疗成人外伤性寰枢椎半脱位

目的:观察改良后的牵引疗法在成人外伤性寰枢椎半脱位中的应用。方法 :对2018年3月至2019年6月收治的31例寰枢椎半脱位患者进行回顾性分析,男15例,女16例;年龄18～68岁,平均39岁,其中18～40岁者10例,41～60岁者15例,51～68岁者6例。主要表现为颈部活动受限,疼痛,寰枢椎CT平扫示不同程度寰枢椎半脱位。运用三维多功能牵引床,牵引2 min,放松10 s,牵引角度以后伸位5°～10°,重量3～6 kg开始,每两天增加重量1 kg,至症状改善后,并以此重量维持治疗。牵引时间为30 min,每天牵引2次,10 d为1个疗程。寰枢椎间隙左右欠等宽1～2 mm者牵引1个疗程,3～4 mm者牵引2个疗程,特别疑难严重者如寰枢椎间隙左右欠等宽4 mm常规疗程无好转者,疗程可以增至3个月。治愈:颈部无疼痛,颈部活动正常范围,CT检查示寰枢椎间隙正常,齿突居中;治疗结束1个月后随访颈部活动正常者。好转:颈部疼痛明显好转,CT检查示寰枢椎间隙左右欠等宽1 mm者。结果:31例患者中,1个疗程治愈者17例;2个疗程治愈者11例,好转2例;3个月治愈者1例。结论:改良后的牵引疗法对成人外伤性寰枢椎半脱位,特别是寰枢椎间隙左右欠等宽3～4 mm的半脱位,有明显的疗效,且此法安全、可靠,患者无不适,疗效较好。     

Conservative management of idiopathic anterior atlantoaxial subluxation without neurological deficits in an 83-year-old female: A case report

Atlantoaxial subluxation that is not related to traumatic, congenital, or rheumatological conditions is rare and can be a diagnostic challenge. This case report details a case of anterior atlantoaxial subluxation in an 83-year-old female without history of trauma, congenital, or rheumatological conditions. She presented to the chiropractor with insidious neck pain and headaches, without neurological deficits. Radiographs revealed a widened atlantodental space (measuring 6 mm) indicating anterior atlantoaxial subluxation and potential sagittal atlantoaxial instability. Prompt detection and appropriate conservative management resulted in favourable long-term outcome at 13-months follow-up. Conservative management included education, mobilizations, soft tissue therapy, monitoring for neurological progression, and co-management with the family physician. The purpose of this case report is to heighten awareness of the clinical presentation of idiopathic anterior atlantoaxial subluxation without neurological deficits. Discussion will focus on the incidence, mechanism, clinical presentation, and conservative management of a complex case of anterior atlantoaxial subluxation.     

类风湿性关节炎继发寰枢椎脱位的手术治疗

目的:总结手术治疗类风湿性关节炎(rheumatoid arthritis,RA)继发寰枢椎脱位的临床疗效。方法:2010年1月~2018年12月收治57例RA继发寰枢椎脱位的患者,男14例,女43例;年龄46~79岁(61.8±12.4岁)。类风湿性关节炎病史2.5~36.8年(17.5±3.7年),诊断RA后出现上颈椎相关症状时间为1.5~19.4年(8.9±2.4年)。患者均有不同程度的枕颈部疼痛、颈部姿势异常和活动受限。术前神经功能ASIA分级:B级3例,C级12例,D级20例,E级22例;JOA评分4~14分(8.7±1.8分),VAS 4~10分(7.4±1.5分)。寰椎前向脱位44例,其中寰齿前间距(anterior atlantodental interval,AADI)>10mm者8例;寰椎后向脱位9例;寰椎前后向脱位4例。6例合并下颈椎不稳,10例合并枕颈部其他畸形。13例枕寰关节先天性融合及骨性融合无枕寰关节活动度者采用枕颈固定融合术治疗(A组);44例有枕寰关节活动度的患者采用寰枢椎融合固定融合术治疗,其中16例寰枢椎脱位牵引不能复位的患者先行前路经下颌下寰枢椎关节松解术再一期后路行寰枢椎融合术治疗(B组),28例寰枢椎脱位牵引能复位的患者直接采用后路寰枢椎融合内固定术治疗(C组)。定期随访患者的临床症状和神经功能改善情况,影像学观察寰枢椎复位和植骨融合情况。结果:患者均顺利完成手术,A组手术时间100~130min(118.2±13.5min),术中出血量100~300ml(190.5±42.8ml);B组手术时间180~240min(221.4±20.3min),术中出血量100~260ml(157.3±36.1ml);C组手术时间100~130min(109.4±12.1min),术中出血量100~200ml(124.1±32.7ml)。术中均未发生椎动脉和脊髓损伤。所有患者随访期间复查颈椎CT及MRI显示寰枢椎序列重建满意,齿状突区域脑脊液线清晰,脊髓无压迫,术后AADI为2~3mm(2.4±0.4mm)。患者均获随访,随访时间12~84个月(34.4±10.3个月),术后12个月随访时,2例ASIA分级B级患者恢复至C级,C级患者6例恢复至D级、3例恢复至E级,9例D级患者恢复至E级,其余患者无变化;JOA评分改善至10~17分(14.6±3.5分),VAS评分降至1~5分(3.6±1.4分),与术前比较均有显著性差异(P<0.05)。1例患者植骨块发生自发性部分吸收,随访1年半时植骨块吸收停止并部分融合,未再次行植骨术;其余患者植骨均融合。随访期间均未发现螺钉松动、移位、断裂和寰枢椎再脱位、失稳现象。结论:RA累及上颈椎时会造成寰枢椎脱位导致脊髓受压,依据枕寰关节活动度情况采用寰枢椎融合术或枕颈融合术治疗可获得良好的临床效果。     

寰枢关节多层螺旋CT旋转功能位影像学观测

目的:通过测量分析正常寰枢关节在多层螺旋CT中立位及旋转功能位的各种影像征象,为临床准确诊断寰枢关节旋转半脱位提供量化标准。方法:对51例正常志愿者进行中立位、左右尽力旋转位扫描,观察测量寰齿前间隙(atlanto-dental interval,ADI),齿突侧块间隙(lateral atlanta-dental space,LADS),齿突侧块间距差值(VBLADS)及寰枢椎相对旋转角度(rotating angle of atlas on dentate,RAAD),分析比较各影像表现及解剖学特点。将51例正常志愿者分为年龄<45岁及年龄≥45岁两组,比较不同年龄段人群VBLADS及RAAD的变化及进行相关性分析。结果:51例正常志愿者通过三维重建软件显示中立位寰枢外侧关节基本对称,齿突侧块间隙不对称者40例,占78.4%.中立位齿突偏移角度范围为(3.22±0.89)°,尽力旋转位寰枢椎(atlanto-axial joint)外侧关节面呈旋转性关节面移位,相对旋转角度范围为(33.85±2.79)°。通过配对资料相关性分析得出在一定范围内寰枢椎相对旋转角度与VBLADS无相关性。<45岁及≥45岁尽力旋转位时寰枢椎相对旋转角度之间差异有统计学意义。结论:多层螺旋CT旋转功能位能清楚显示寰枢区的解剖结构及旋转功能,为诊断寰枢关节旋转半脱位提供理论依据。