Stage-related surgery for cervical spine instability in rheumatoid arthritis

Thirty-six consecutive patients with cervical spine instability due to rheumatoid arthritis (RA) were treated surgically according to a stage-related therapeutic concept. The aim of this study was to investigate the clinical results of these procedures. The initial change in RA of the cervical spine is atlanto-axial instability (AAI) due to incompetence of the cranio-cervical junction ligaments, followed by development of a peridontoid mass of granulation tissue. This results in inflammatory involvement of, and excessive dynamic forces on, the lateral masses of C1 and C2, leading to irreducible atlanto-axial kyphosis (AAK). Finally, cranial settling (CS) accompanied by subaxial subluxation (SAS) occurs. According to these three separate pathological and radiological lesions, the patients were divided into three therapeutic groups. Group I comprised 14 patients with isolated anterior AAI, who were treated by posterior wire fusion. Group II comprised 15 patients with irreducible AAK, who were treated by transoral odontoid resection. The fixation was done using anterior plating according to Harms in combination with posterior wire fusion according to Brooks. Group III comprised seven patients with CS and additional SAS, who were treated with occipito-cervical fusion. Pre- and postoperatively, evaluation was performed using the parameters pain (visual analog scale), range of motion (ROM), subjective improvement and Health Assessment Questionnaire (HAQ). The neurologic deficit was defined according to the classification proposed by Ranawat. Radiographs including lateral flexion and extension views, and MRI scans were obtained. The average clinical and radiographic follow-up of all patients was 50.7 ± 19.3 months (range 21–96 months). No perioperative fatality occurred. Postoperative pain was significantly relieved in all groups (P < 0.001). In group II a slight improvement in the HAQ was obtained. In groups I and II the ROM of all patients increased significantly (average gain of motion in group I: 11.3°± 7.8° for rotation; 7.8°± 5.6° for bending; average gain of motion in group II: 21.5°± 14.0° for rotation; 17.2°± 5.5° for bending), while it decreased significantly in group III (10.7°± 18.1° for rotation; 6.7°± 18.5° for bending). Preoperatively 27 patients had a manifest neurologic deficit. At follow-up four patients remained unchanged, all others improved by at least one Ranawat class. All patients, except one, showed solid bony fusion. According to the significantly improved postoperative subjective self-assessment and the clinical and radiological parameters, transoral plate fixation combined with posterior wire fixation after transoral odontoid resection represents an effective reliable and safe procedure for the treatment of irreducible AAK in rheumatoid arthritis. Received: 4 March 1999 Accepted: 19 May 1999     

Biomechanical assessment of transoral plate fixation for atlantoaxial instability

STUDY DESIGN: In an experimental study using human cadaver specimens the biomechanical data of anterior atlantoaxial plating according to Harms were evaluated. OBJECTIVES: The purpose of this study was to evaluate this method biomechanically. SUMMARY AND BACKGROUND DATA: The optimum fixation method to achieve fusion at the atlantoaxial joint after odontoid resection is still a matter of discussion. Isolated posterior surgical procedures for treatment of irreducible atlantoaxial kyphosis with spinal cord compression are associated with high rates of morbidity and mortality. Transoral atlantoaxial plate fixation has been designed by Harms as a fixation technique after odontoid resection. In a modification, this procedure has been combined with the posterior wire fusion according to Brooks. METHOD: Eight human cadaver craniocervical specimens were tested in flexion, extension, rotation, and bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Five different groups were examined: 1) control group (intact); 2) unstable group (after dissection of the atlantoaxial ligaments and odontoidectomy), 3) Harms group (transoral atlantoaxial plate fixation) 4) Harms-Brooks group (transoral atlantoaxial plate fixation and dorsal atlantoaxial wire fixation); and 5) Magerl group (transarticular atlantoaxial screw fixation). In a second experimental series, failure loads of the Harms-Brooks and the Magerl fixation methods were determined. RESULTS: The angular displacement of the Harms-Brooks group and the Magerl group was less than in any other group. Stiffness values at 0-3.0 Nm loads in any direction were larger for the Harms-Brooks-and Magerl-fixated specimens than for the Harms, control, or unstable specimens. No statistically significant difference was observed between Harms-Brooks and Magerl reconstruction stiffness. Ultimate failure load in the Harms-Brooks group was higher than in the Magerl group. CONCLUSIONS: Experimentally, isolated anterior atlantoaxial plating was less stable than the combined reconstruction procedures. Transoral plate fixation according to Harms in combination with posterior wire fixation according to Brooks provided a failure load and stiffness equal to transarticular screw fixation according to Magerl.     

Odontoid fractures: A retrospective analysis of 53 cases

Background:

The management of odontoid fracture has evolved but controversy persists as to the best method for Type II odontoid fractures with or without atlantoaxial (AA) instability. The anterior odontoid screw fixation can be associated with significant morbidity while delayed odontoid screw fixation has shown to be associated with reasonable good fusion rates. We conducted a retrospective analysis to evaluate the outcome of a trial of conservative management in type II odontoid fractures without atlantoaxial instability (Group A) followed by delayed odontoid screw fixation in cases in which fusion was not achieved by conservative treatment. The outcome of type II odontoid fracture with AA subluxation (Group B) was also analysed where closed reduction on traction could be achieved and in those atlantoaxial subluxations that were irreducible an intraoperative reduction was done.

Materials and Methods:

A retrospective evaluation of 53 cases of odontoid fractures treated over a 9-year period is being reported. All odontoid fractures without AA instability (n=29) were initially managed conservatively. Three patients who did not achieve union with conservative management were treated with delayed anterior screw fixation. Twenty-four cases of odontoid fractures were associated with AA instability; 17 of them could be reduced with skeletal traction and were managed with posterior fusion and fixation. Of the seven cases that were irreducible, the initial three cases were treated by odontoid excision followed by posterior fusion and fixation; however, in the later four cases, intra operative reduction was achieved by a manipulation procedure, and posterior fusion and fixation was performed.

Results:

Twenty-six of 29 cases of odontoid fracture without AA instability achieved fracture union with conservative management whereas the remaining three patients achieved union following delayed anterior odontoid screw fixation. 17 out of 24 odontoid fracture with atlantoaxial dislocation could be reduced on traction and these patients underwent posterior fusion and fixation. Optimal or near optimal reduction was achieved by on table manipulation in four cases which were irreducible with skeletal traction. Atlantoaxial stability was achieved in all cases. All cases were noted to be stable on evaluation with x-rays at six months.

Conclusions:

The initial conservative management and use of odontoid screw fixation only in cases where conservative management for 6–12 weeks has failed to provide fracture union have shown good outcome in type II odontoid fracture without AA instability rates. Intraoperative manipulation and reduction in patients where AA subluxation failed to reduce on skeletal traction followed by posterior fusion obviates the need for transoral odontoid excision.     

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.      

一期前路松解后路椎弓根钉固定融合治疗难复性寰枢椎脱位

目的 探讨经口咽入路前路松解一期后路寰枢椎椎弓根钉内固定植骨融合治疗难复性寰枢椎前脱位的临床疗效,方法 2005年1月～2010年2月,采用经口咽入路前路松解,一期后路寰枢椎椎弓根钉内固定植骨融合治疗难复性寰枢椎脱位合并高位颈脊髓压迫共21例.男15例,女6例;年龄26～70岁,平均51岁;病程6～30年.陈旧性齿状突...     

Reduction techniques in the management of atlantoaxial subluxation

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

前路松解复位后路内固定治疗难复性寰枢关节脱位

目的：探讨难复性寰枢关节脱位的手术治疗方法。方法：对3例难复性寰椎前脱位的病例经口咽入路切断颈长肌、头长肌、前纵韧带和寰枢侧块关节囊，施行松解复位术，同期行后方固定植骨融合术。后方固定方法包括：经寰枢侧块关节螺钉固定、寰枢侧块钉板固定和借助于枢椎椎弓根螺钉的枕颈固定。结果：3例均获得了解剖复位和植骨融合。结论：经口咽入路的寰枢关节松解复位术可使难复性脱位的寰枢关节获得充分复位，松解复位术是一种安全、有效的治疗方法。     

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.     

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.     

Biomechanical study of angle-stable anterior atlanto-axial spondylodesis plate

The optimum fixation method to achieve atlantoaxial fusion after odontoid resection is still subject to discussion. Isolated posterior surgical procedures for treatment of irreducible atlantoaxial kyphosis with spinal cord compression are associated with a high rate of morbidity and mortality. Transoral atlantoaxial plate fixation has been described by Harms as a fixation technique after odontoid resection. The purpose of this study was to compare biomechanically a new anterior atlantoaxial locking plate (AALP) with the Harms plate and the atlantoaxial transarticular screw fixation described by Magerl. Sixteen human cadaver craniocervical specimens were tested in flexion, extension, rotation, and bending with a nondestructive flexibility method using a nonconstrained testing apparatus. Five different groups were examined: (1) control group (intact) (n = 16), (2) unstable group (after dissection of the atlantoaxial ligaments and odontoidectomy) (n = 16), (3) Harms group (transoral atlantoaxial plate fixation) (n = 8), (4) AALP group (anterior atlantoaxial locking plate fixation) (n = 8), and (5) Magerl group (transarticular atlantoaxial screw fixation) (n = 16). Stiffness in any direction was significantly higher in the AALP specimens and those fixated with the Magerl method than in the Harms, control, or unstable specimens. The difference in stiffness between the AALP and Magerl reconstruction groups was not statistically significant. Experimentally, the AALP was significantly stiffer than the Harms plate. The AALP provided stiffness equal to transarticular screw fixation according to Magerl. A question that cannot be answered by this in vitro study concerns the level of rigidity required to obtain long-term stability and fusion by atlantoaxial fixation methods. However, it may be assumed that the more spinal motion is eliminated the greater the chance of definite spinal fusion. Therefore, it seems reasonable that the most reliable and rigid fixation method would be the method of choice.     

难复性寰枢关节脱位的手术治疗

目的探讨难复性寰枢关节脱位的手术治疗方法。方法54例难复性寰枢关节脱位患者,男32例,女22例;年龄7～63岁,平均32岁。其中齿突不连18例,寰椎枕骨化畸形22例,齿突骨折畸形愈合5例,寰椎横韧带松弛9例。40例有脊髓病或脊髓损伤的症状、体征。先行经口咽入路的寰枢关节松解复位术,术中横断挛缩的椎前肌、前纵韧带和侧块关节囊,借助于牵引和器械撬拨的力量使寰枢关节复位;同期行后路寰枢或枕颈固定植骨融合术,后路固定方法包括经寰枢侧块关节螺钉固定5例、寰枢侧块钉板固定12例和借助于枢椎椎弓根螺钉与枕颈固定板的枕颈固定37例。术后不用外固定。结果41例获得解剖复位;13例部分复位,其中2例行部分齿突切除,另11例术前颈髓角平均104.1°,术后120.2°。48例随访4～40个月,平均15.7个月,全部病例均获骨性融合。术前有脊髓症状的38例术后功能评价(Odom标准)为优15例,良14例,可8例,差1例。术中出现硬膜破裂1例,椎弓根钉切割1例;术后出现呼吸衰竭1例,发音不正常3例,吞咽不利1例,术后2周发生败血症脊髓炎致瘫痪1例,术后2个月内固定松动1例。结论经口咽入路寰枢关节松解复位结合后路坚强内固定及植骨融合,对难复性寰枢关节脱位有良好的治疗效果。     

Die atlantoaxiale Kyphose

Atlantoaxial kyphosis (AAK) is a rare sagittal deformity of the occiptoatlantoaxial junction. It is defined as a subgroup of anterior translatory atlantoaxial instability. AAK is a symptom of several ligamentours or bony disorders of the craniocervical junction; however, rheumatoid arthritis and trauma are the most common causes for AAK. AAK can be diagnosed on lateral radiographic views of the upper cervical spine if the angle between McGregor's line and the atlas plane is less than-15 degrees or the atlas-axis angle is greater 105 degrees. Treatment modalities for AAK depend on the ability to reduce the deformity. If closed reduction is achieved, posterior atlantoaxial fusion by sublaminar wiring according to Brooks or transarticular screw fixation according to Magerl are possible choices. Irreducible AAK can be treated with a combined transoral decompression, anterior plating according to Harms, and posterior wiring according to Brooks. This staged therapy for AAK was successful in our rheumatoid patient population with AAK.     

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.     

前弓切除联合后路固定治疗齿突骨折畸形愈合

 目的探讨经口前路寰椎前弓切除、寰枢椎侧块关节松解联合后路复位内固定融合术治疗齿突骨折畸形愈合伴难复性寰枢椎脱位的疗效。方法2007年2月至2012年2月共收治6例齿突骨折畸形愈合伴难复性寰枢椎脱位患者,均有外伤史,均存在脊髓损伤表现。男5例,女1例;年龄36~57岁,平均45.5岁。术前日本骨科协会（Japanese Orthopaedic Association,JOA）评分为4~10分,平均（7.5±2.2）分;脊髓有效空间（space available for cord,SAC）为5~11 mm,平均（8.1±2.5） mm。采用经口前路寰椎前弓切除、寰枢椎侧块关节松解联合后路枕颈复位固定融合术,术后颈托外固定3个月。术后观察神经功能改善情况,行X线、CT检查观察寰枢椎复位及融合情况。结果6例患者均获得随访,随访时间12~20个月,平均16个月。寰枢椎术中得到较好复位,术后3个月获得骨性融合,随访期间内固定无松动。6例患者神经功能末次随访时JOA评分为10~15分,平均（14.7±2.1）分,较术前明显提高（差异有统计学意义）,神经功能改善率75.5%。末次随访时SAC为11~17 mm,平均（13.5±2.6） mm,较术前明显增大,差异有统计学意义。1例术后第5天出现后路切口渗液,督促患者采取侧卧位,避免切口受压,3周后切口愈合。1例术后第3天出现神智淡漠,化验室检查显示低钠、低钾血症,经及时补液,1 d后神智恢复正常。结论经口前路寰椎前弓切除、寰枢关节松解联合后路复位固定融合术是治疗齿突骨折畸形愈合伴难复性寰枢椎脱位的安全、有效方法,临床效果满意。     

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-transpharyngeal approach to the anterior craniocervical junction. Ten-year experience with 72 patients

The anterior transoral-transpharyngeal operation to correct ventral irreducible compression of the cervicomedullary junction was utilized in 72 individuals. The patients' ages ranged from 6 to 82 years, and 29 were children. The pathology encountered was primary basilar invagination, rheumatoid irreducible cranial settling, secondary basilar invagination due to migration of odontoid fracture fragments, dystopic os odontoideum, granulation masses, clivus chordoma, osteoblastoma, and chondroma of the atlas. Fifteen patients had associated Chiari malformation with basilar invagination. Fifty-two patients required subsequent atlantoaxial or occipitocervical fusion. Neurological improvement was the rule. There were two deaths within 30 days of surgery: one from myocardial infarction 4 weeks after surgery and one from Gram-negative septicemia of urinary tract origin. There was one pharyngeal wound infection. The ventral transoral approach provides a safe, rapid, and effective means for decompression of the abnormal craniovertebral junction.     

前后路联合手术治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位

目的:探讨经口前路松解齿状突部分切除与后路复位固定融合治疗齿状突骨折畸形愈合伴难复性寰枢椎脱位的疗效。方法:2008年1月～2011年1月我院共收治7例齿状突骨折畸形愈合致难复性寰枢椎脱位患者,男5例,女2例,年龄21～51岁,平均36.4岁。术前神经功能JOA评分为5～9分,平均7.3±2.1分;脊髓有效空间(space available for the cord,SAC)为4～12mm,平均8.34±3.68mm。均行经口前路松解、齿状突部分切除,一期后路寰枢椎椎弓根螺钉系统进一步提拉复位、固定、融合术,术后观察神经功能改善情况,并行X线、CT、MRI检查观察复位及植骨融合情况。结果:手术时间280～360min,平均310min。术中出血510～930ml,平均670ml。术中无脊髓神经损伤;1例术中置入枢椎椎弓根螺钉时损伤椎动脉,经原钉道拧入螺钉后完成止血,术后随访无椎动脉损伤的临床表现;1例术中置入寰椎椎弓根螺钉时寰椎后弓下壁破裂,未改变钉道,继续沿椎弓根方向置入螺钉,术后随访无寰枢椎的再失稳和移位。所有患者均获得满意复位。随访9～36个月,平均19.6个月。均在术后6个月获得骨性融合,随访期间未发现螺钉松动、移位、断裂,无寰枢椎再移位、失稳现象。末次随访时,JOA评分为11～15分,平均13.1±2.1分,与术前比较有统计学差异(P<0.05),改善率为78.8%～93.5%,平均87.4%;末次随访时的SAC为11～18mm,平均14.78±2.15mm,与术前比较明显增大(P<0.05)。结论:对于齿状突骨折畸形愈合伴难复性寰枢椎脱位患者,经口咽前路松解齿状突部分切除与后路复位固定融合术可获得好的复位效果,近期疗效满意。     

内窥镜辅助下经颈动脉三角区前路松解治疗难复性寰枢关节脱位(附12例初步报告)

目的：探讨内窥镜辅助下经颈动脉三角前路松解治疗难复性寰枢关节脱位的手术方法。方法：12例难复性寰枢关节脱位患者，男性4例，女性8例，年龄16～48岁，平均31．6岁；病程24～48个月。平均20个月。其中陈旧性齿状突骨折5例，齿状突不连3例，横韧带松弛症3例，齿状突短小合并寰枕融合畸形1例。术前颈脊髓功能JOA评分平均9．3分。在内窥镜辅助下经颈动脉三角区前路C1、C2松解，清除寰枢椎前方挛缩瘢痕组织(或骨)连接，颅骨牵引复位，一周后行后路内固定融合手术。结果：前路平均手术时间70min，出血量150ml。松解后11例获得解剖复位，行寰枢椎固定；1例部分复位，行枕颈融合。术后随访3～12个月，无手术切口感染和内固定失败。术后JOA评分平均15．2分，术后功能改善率76．6％。结论：内窥镜辅助下经颈动脉三角区前路松解治疗难复性寰枢关节脱位创伤小、术野清晰、安全有效。     

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.