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.     

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.     

Biomechanical evaluation of atlantoaxial transarticularscrew fixation technique

Ｐｏｓｔｅｒｉｏｒａｔｌａｎｔｏａｘｉａｌｆｉｘａｔｉｏｎｔｅｃｈｎｉｑｕｅｓａｒｅｎｏｗｗｉｄｅｌｙａｃｃｅｐｔｅｄｉｎｍａｎａｇｅｍｅｎｔｏｆｔｒａｕｍａｔｉｃｏｒｐａｔｈｏｌｏｇｉｃａｔｌａｎｔｏａｘｉａｌｉｎｓｔａｂｉｌｉｔｙ .Ａｍｏｎｇｔｈｅｍ ,Ｇａｌｌｉｅ ｓｗｉｒｉｎｇ ,Ｂｒｏｏｋｓ ｏｒｍｏｄｉｆｉｅｄＢｒｏｏｋｓ ｗｉｒｉｎｇ ,ａｎｄＨａｌｉｆａｘｉｎｔｅｒｌａｍｉｎａｒｃｌａｍｐｆｉｘａｔｉｏｎａｒｅｍｏｒｅｃｏｍｍｏｎａｎｄｐｒｏｖｅｄｔｏｂｅｓｕｐｅｒｉｏｒｔｏｏｔｈｅｒｅ…     

寰枢椎后路椎弓根螺钉固定的生物力学评价

目的：评价寰枢椎后路椎弓根螺钉固定的生物力学稳定性。方法：6具新鲜颈椎标本，按随机顺序，对每一标本先后行C1-C2椎弓根螺钉、Magerl螺钉、Brooks钢丝以及螺钉联合钢丝固定，在脊柱三维运动实验机上测量其三维运动范围。结果：Magerl螺钉或C1-C2椎弓根螺钉联合Brooks钢丝组成的固定系统的三维运动范围最小。C1-C2椎弓根螺钉固定的前后屈伸运动范围与Brooks钢丝固定无差异，但大于Magerl螺钉；其左右侧屈运动范围小于Brooks钢丝固定，大于Magerl螺钉；其轴向旋转角度明显小于Brooks钢丝固定，但与Magerl螺钉无统计学差异。结论：C1-C2椎弓根螺钉的三维稳定性与Magerl螺钉相当，联合Brooks钢丝固定可进一步提高其稳定性。     

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.     

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。     

Anterior C1-C2 screw fixation and bony fusion through an anterior retropharyngeal approach

We present a case that demonstrates an occasion where an alternative method of C1-C2 fusion may be used when a posterior approach limited to the atlantoaxial level is not desirable. A 22-year-old man presented with a symptomatic nonunited Brooks posterior atlantoaxial fusion following a chronically displaced type II odontoid fracture with a two-part fracture of the posterior arch of C1. An anterior retropharyngeal approach was used to perform an anterior C1-C2 fusion with screw fixation. The surgical technique, as well as the merits and indications of this infrequently used procedure, are discussed.     

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 vertical and subaxial subluxation can be prevented by atlantoaxial posterior screw fixation

Purpose

Literature has described a risk for subsequent vertical subluxation (VS) and subaxial subluxation (SAS) following atlantoaxial subluxation in rheumatoid patients; however, the interaction of each subluxation and the radiographic findings for atlantoaxial fixation has not been described. The purpose of this study was to evaluate the effects of two different posterior atlantoaxial screw fixation on the development of subluxation in patients with rheumatoid atlantoaxial subluxation.

Methods

Between 1996 and 2006, rheumatoid patients treated with transarticular fixation and posterior wiring (TA) or C1 lateral mass–C2 pedicle screw fixations (SR) in the Nagoya Spine Group hospitals, a multicenter cooperative study group, were included in this study. VS, SAS, craniocervical sagittal alignment, and range of motion (ROM) at the atlantoaxial adjacent segments were investigated to determine whether posterior atlantoaxial screw fixation is a prophylactic or a risk factor for the development of VS and SAS.

Results

The mean follow-up was 7.2 years (4–12). No statistically significant difference was observed among the patients treated with either of the procedure during the follow-up period. Of 34 patients who underwent posterior atlantoaxial screw fixation, SAS was observed in 26.5 % during the follow-up period; however, VS was not observed. Postoperative C2–7 angle, and Oc–C1 and C2–3 ROM were significantly different between patients with and without postoperative SAS. The incidence of SAS was 38.9 % for TA and 12.5 % for SR; statistically significant differences were observed in the postoperative C1–2 and C2–7 angles, and C2–3 ROM.

Conclusions

Atlantoaxial posterior screw fixation may be an appropriate prophylactic intervention for VS and SAS if the atlantoaxial joint develops bony fusion following physiological alignment. Compared to TA, SR provided optimal atlantoaxial angle and prevented lower adjacent segment degeneration, thereby reducing SAS.     

Principles of surgical treatment of the cervical spine in rheumatoid arthritis

Summary About 20% of patients with rheumatoid arthritis complain about neck problems based on instability and deformity. As a consequence, pain, myelopathy, and severe neurological deficit may occur. Results reported in the literature were not encouraging as regards surgical decompression and stabilization. However, new surgical techniques allow a more aggressive strategy towards the complex problem of the instable cervical spine in rheumatoid arthritis. The most frequent instability of C1/2 can be stabilized by a posterior atlantoaxial screw fixation, a three-dimensional multidirectional construct with few complications. For the inclusion of the occiput into the fusion and the extension of the fusion down to the lower cervical spine, a titanium Y-plate is presented as a successful implant. While through a posterior approach, stability may be achieved, decompression is preferably done by anterior diskectomy or vertebrectomy. Encouraging results with a significant recovery of neurological deficits justify an early intervention in cases of instability of the cervical spine in rheumatoid arthritis.     

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.     

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.     

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     

Surgical stabilization of the cervical spine. A comparative analysis of anterior and posterior spine fusions

Two hundred twenty-two cervical spine stabilization procedures in 212 patients are reviewed. In 114 posterior cervical fusions, 88 anterior fusions, and ten combined procedures, no deaths occurred. Surgical complication rates were similar, but more severe complications were noted with anterior cervical fusions, including tracheoesophageal problems and transient neurologic loss. Six cases of graft dislodgement requiring reoperation also occurred. In long-term follow-up evaluations, 36 anterior fusion patients developed progressive kyphotic deformity averaging 22 degrees between surgery and the time solid fusion was obtained. Degenerative changes above and below the fusion mass were detected in 36 of 59 patients treated by anterior surgery. Posterior cervical fusion patients were noted to have no significant late change in alignment, and degenerative changes were infrequent. However, 73 of 98 patients had significant extension of fusion mass beyond the originally intended levels of stabilization. Because anterior cervical spine fusion was associated with significant complications of graft dislodgement and tracheoesophageal trauma, as well as postsurgical progressive deformity, the authors recommend posterior wiring and fusion as the procedure of choice to treat cervical spine instability and permit halo-free postsurgical rehabilitation. When anterior neural decompression and fusion is necessary, concomitant posterior wiring and fusion or halo vest immobilization may be necessary to maintain reduction and prevent kyphotic angulation, because posterior ligamentous disruption is not always grossly evident on radiographic examination.     

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.     

Occipitocervical fusion in patients with rheumatoid arthritis

Instability and deformity of the cervical spine caused by rheumatoid arthritis is a well known entity. Operative intervention is indicated for patients with progressive deformity and when pain is resistant to conservative treatment. In a series of 39 patients who underwent posterior occipitocervical fusion with a Y plate, 22 patients were observed clinically and radiographically at average 41.5 months after surgery. In 35 of the 39 patients the main indication for surgery was pain, and in 30 of the 39 patients additional neurologic deficit (radiculopathy or myelopathy) was present. Thirty-one of the 39 patients had atlantoaxial instability. The atlantoaxial instability was associated with cranial migration of the dens in 19 patients. According to the classification of Conaty and Mongan 77.3% patients had satisfactory results and 22.7% had unsatisfactory results. Of the 30 patients with neurologic deficit, nine patients had a significant improvement. No patient had a worse result after surgery. Solid fusion was seen in all 22 patients at followup. Seven patients experienced complications directly related to the surgical procedure. Posterior fixation combined with anterior decompression in the presence of spinal stenosis represents a useful and safe method to treat instability and deformity caused by rheumatoid arthritis. Early surgical procedures may reduce the complication rate.     

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.     

Combined anterior and posterior fusion for spinal deformity in myelomeningocele

Since 1973, 50 of 54 children have been treated by the author with a combined anterior and posterior fusion. Twenty males and 34 females, ranging in age from 1 to 16 years, have been followed for a mean period of 5.5 years. Sixteen patients with a kyphosis averaging 113 degrees (range, 77 to 170 degrees) had correction of deformity to a mean of 35 degrees. Thirty-seven patients with a scoliosis averaging 73 degrees (range, 20 to 135 degrees) had correction to an average of 34 degrees (range, 0 to 75 degrees). There were 4 cases of deep wound infection successfully treated with drainage and antibiotics and only one case required implant removal after fusion/maturation. A pseudarthrosis was noted by radiograph in 6 patients, 3 of whom had isolated asymptomatic lumbosacral pseudarthroses. Three patients had pseudarthrosis at the thoracolumbar junction. These required repair and were successfully treated by supplemental posterior fusion resulting in an overall pseudarthrosis rate of 5.7%. Anterior fusion of the dysraphic spine allows greater correction of both spinal deformity and pelvic obliquity in addition to contributing significant strength to the fusion mass. Segmental spinal instrumentation with sublaminar and pedicular wiring to custom-contoured Luque rods provides excellent correction and immediate postoperative stability.     

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.     

前路松解复位后路融合治疗游离齿突继发环枢椎脱位

目的: 探讨经高位咽后入路前路松解、后路融合治疗游离齿突继发的难复性环枢椎脱位。方法: 本组 3例, 均为男性, 年龄 17~36岁, 无明显创伤史, 颅骨牵引 2~3周, 采用高位咽后入路显露C1~3, 行环枢前方松解复位, Ⅰ期后路环枢融合, Brooks法钛缆内固定。结果: 3例游离齿突继发的难复性环枢椎脱位, 术前颅骨牵引不能复位, 经前路手术松解达到良好复位, 后路环枢融合良好, 内固定无松脱, 无伤口感染。3例患者神经症状均明显改善。结论: 经高位咽后入路行前方松解, 能够复位游离齿突继发的难复性环枢椎脱位, Ⅰ期后路环枢融合可获良好的植骨融合。