Single-stage Anterior Release and Sequential Posterior Fusion for Irreducible Atlantoaxial Dislocation

A Three-Step Submandibular Retropharyngeal Approach to the Craniovertebral Junction: Is Less Always More?

Background: Accessing the craniovertebral junction poses unique challenges due to its anatomical complexity and proximity to critical structures, such as the cord-brainstem junction, great vessels of the neck, cranial nerves, oropharynx, and rhinopharynx. Among the approaches that have been developed over the years, the submandibular retropharyngeal approach offers good antero-lateral access without the need of transgressing mucosal layers. In its traditional form, however, this approach involves multiple sequential steps and requires intricate dissection, extensive retraction, and meticulous maneuvering, which can increase operative time and produce approach-related morbidity. Methods: With this paper, we propose a simplified technique for a submandibular retropharyngeal approach involving only three surgical steps. The advantages and limitations of this technique are illustrated through three surgical cases of neoplastic and degenerative craniovertebral junction pathologies. Results: In two out of the three cases, our technique allowed for a wide exposure of the lesions that could be resected totally or sub-totally with good outcome. In one case with involvement of the clivus and the occipital condyle, the exposure was inadequate; a biopsy was obtained, and the lesion was subsequently resected via and endoscopic transmucosal approach. Conclusions: Our technique represents a significant simplification of the traditional submandibular retropharyngeal approach; with appropriate indication, it permits a fast, safe, and adequate exposure of craniovertebral junction pathologies.

Treatment of irreducible atlantoaxial dislocation by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach

OBJECTIVE

Investigate a novel method for treating irreducible atlantoaxial dislocation (IAAD) or with basilar invagination (BI) by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach.

METHOD

From March 2015 to December 2019, 213 consecutive patients diagnosed as IAAD/BI were treated with transoral bony deformity remodeling and releasing combined with plate fixation. The main clinical symptoms include neck pain, headache, numbness of the limbs, weakness, unstable walking, inflexible hand-held objects, and sphincter dysfunction. The bony factors that impact reduction were divided into as follows: type A1 (sloping of upper facet joint in C2), type A2 (osteophyte in lateral mass joints between C1 and C2), type A3 (ball-and-socket deformity of lateral mass joint), type A4 (vertical interlocking between lateral mass joints of C1-C2), type A5 (regional bone fusion in lateral mass joints), type B1 (bony factor hindering reduction between the atlas-dens gap), type B2 (uncinate odontoid deformity), and type B3 (hypertrophic odontoid deformity). All of them were treated with bony deformity osteotomy, remodeling, and releasing techs.

RESULT

The operation time was 144 [Formula: see text] 25 min with blood loss of 102 [Formula: see text] 35 ml. The average pre-operative ADI improved from 7.5 [Formula: see text] 3.2 mm pre-surgery to 2.5 [Formula: see text] 1.5 mm post-surgery (p < 0.05). The average VDI improved from 12.3 [Formula: see text] 4.8 mm pre-surgery to 3.3 [Formula: see text] 2.1 mm post-surgery (p < 0.05). The average pre-operative CMA improved from 115 [Formula: see text] 25° pre-surgery to 158 [Formula: see text] 21° post-surgery (p < 0.05); the pre-operative CAA changed from 101 [Formula: see text] 28° pre-surgery to 141 [Formula: see text] 10° post-surgery. After the operation, the clinic symptoms improved, and the JOA score improved from 9.3 [Formula: see text] 2.8 pre-operatively to 13.8 [Formula: see text] 2.5 in the sixth months of follow-up.

CONCLUSION

In addition to soft tissue factors, bony obstruction was another important factor impeding atlantoaxial reduction. Transoral bony deformity osteotomy, remodeling, releasing combined with plate fixating was effective in treating IAAD/BI with bony obstruction factors.

Atlantoaxial Dislocation with Bony Fusion of C1/2 Facet Joints Treated with Posterior Joint Release, Distraction and Reduction

Introduction

Atlantoaxial dislocation (AAD) is a complicated and challenging deformity with severe morbidities. Irreducible AAD with C1/2 bony fusion requires anterior (transoral or transnasal) odontoidectomy to decompress spinal cord or medulla, which is highly demanding technique that is risky for comorbidities. Here, we report our application of modified Goel's technique to reduce AAD with bony fusion through single-stage posterior approach surgery.

Technical Note

Our technique that can reduce AAD with bony fusion through single-stage posterior approach surgery is reported. Joint release, distraction, cage implantation, and atlantoaxial or occipitocervical fixation can successfully manage AAD with C1/2 bony fusion. Key points for the technique include pinpointing original joint space, thorough release of bony fusion, stepwise distraction, and cage implantation with autograft.

Conclusions

Joint release, distraction, cage implantation, and atlantoaxial or occipitocervical fixation can successfully manage bony irreducible AAD. This technique provided an option for bony fused AAD and improved safety and efficacy of its management.

Management of Neglected Upper Cervical Spine Injuries

BACKGROUND

Injuries involving upper cervical spine are serious and fatal injuries which are associated with alteration of normal occipital-cervical anatomy. These injuries may result in permanent neurologic deficits or neck deformity if not treated in a timely and appropriate manner.

OBJECTIVE

To evaluate the outcomes of neglected upper cervical spine injuries treated by various methods.

STUDY DESIGN

Retrospective study.

MATERIALS AND METHODS

Twelve patients attending ER or OPD with a history of neck trauma and who were diagnosed with fractures and fracture dislocations C1 and C2 were included in the study. Fresh injuries sustained within a week were excluded from study. The outcomes were measured in terms of improvement in VAS, ODI Scores and correction of the neck deformity. Surgical parameters like duration of surgery and blood loss were also observed.

RESULTS

Eleven males and one female. The mean age was 40.9 ± 16.9 (07-67 years). Eleven patients underwent posterior instrumentation, while one patient was treated anteriorly. The mean delay in presentation was 28 ± 8.67 days (15-42 days). The mean duration of surgery was 188.3 ± 34.35 min (120-240 min), average blood loss was 350 ± 111.8 ml (150-600 ml). The mean VAS improved from 8.45 ± 0.89 to 3.9 ± 0.51 (p < 0.05). The mean ODI Pre-operatively was 88.45 ± 5.89 which improved to 31.9 ± 4.01 (p < 0.05). The neck deformity/torticollis was corrected in all the patients.

CONCLUSIONS

Neglected upper cervical spine injuries are difficult to treat and a posterior approach is helpful in reducing the subluxations indirectly and to obtain a posterior fusion.

Treatment of irreducible atlantoaxial dislocation using one-stage retropharyngeal release and posterior reduction

INTRODUCTION

Irreducible atlantoaxial dislocation (IAAD) has been challenging for spine surgeons. Various methods have been used to treat IAAD, but no consensus has been reached. This study aimed to retrospectively analyze the efficacy of anterior submandibular retropharyngeal release and posterior reduction and fixation for IAAD.

METHODS

From March 2007 to May 2015, 13 patients diagnosed with IAAD underwent anterior submandibular retropharyngeal release and sequential posterior reduction and fixation. The operation time, blood loss, postoperative complications, and Japanese Orthopaedic Association (JOA) scores were retrospectively recorded.

RESULTS

The surgeries were accomplished successfully. The mean operative time was about 3.8 h. The mean estimated blood loss was about 130 mL. The patients experienced postoperative pharyngeal pain. Only one patient had a vague voice and increased oral discharge postoperatively. At the final follow-up, JOA scores had significantly increased (p < 0.05), and all the patients had solid bony fusion.

CONCLUSION

The present study reinforces the efficacy and safety of anterior submandibular retropharyngeal release and posterior reduction and fixation for IAAD. It can achieve satisfactory clinical outcomes and is safe for experienced spine surgeons.

Anterior release without odontoidectomy for irreducible atlantoaxial dislocation: transoral or endoscopic transnasal?

PURPOSE

To compare transoral and endoscopic transnasal anterior release without odontoidectomy and posterior reduction and fixation to treat irreducible atlantoaxial dislocation (IAAD).

METHODS

From June 2006 to January 2017, 35 consecutive patients with IAAD underwent transoral (Tr-Oral group) or endoscopic transnasal (Tr-Nasal group) release and posterior fixation and fusion in our department. Clinical neurological recovery (Japanese Orthopedic Association (JOA) score) and radiological reduction parameters including atlantodontoid interval (ADI), space available for the cord (SAC) and cervicomedullary angle (CMA) were analyzed and compared. The operation duration, blood loss, length of intensive care unit (ICU)/hospital stay and complications were recorded.

RESULTS

All 35 patients (18 and 17 patients in the Tr-Oral and Tr-Nasal groups, respectively) were followed up for a mean of 36.4 months (range, 21-60 months). All patients achieved excellent anatomical reduction and clinical neurological recovery, with no significant differences between the two groups. The JOA score, ADI, SAC and CMA were not significantly different between the two groups at various postoperative points. Although the Tr-Oral group had shorter operation time and less blood loss than the Tr-Nasal group, the Tr-Nasal group tended to have a significantly shorter hospital/ICU stay, earlier extubation and earlier oral intake than the Tr-Oral group.

CONCLUSION

The transoral and endoscopic transnasal approaches can achieve equivalent release and reduction effects when treating IAAD. Compared to the transoral approach, the endoscopic transnasal route is less invasive with earlier extubation and oral intake, shorter hospital/ICU stays and lower medical costs, which is conducive to enhanced recovery after surgery.

Simplified four-step retropharyngeal approach for the upper cervical spine: technical note

PURPOSE

In this paper, we propose a simplified four-step retropharyngeal approach, whose aim is getting straight to the upper cervical spine minimizing complications.

METHODS

While the classical retropharyngeal approach includes about 11 steps, ours is a four-step approach: patient positioning, skin-platysma incision, hyoid bone superolateral dissection and retropharyngeal blunt exposure. We avoid several steps of the classical anterior retropharyngeal approach, particularly dissection of submandibular gland, facial veins, external carotid artery and thyroid artery, bellies of the digastric muscle, hypoglossal nerve, thyrohyoid membrane and the internal branch of superior laryngeal nerve.

RESULTS

We have adopted this technique for five patients: two patients had a C2-C3 herniated disk with myelopathy, two patients had unstable Hangman fracture with no bone fusion after 2-month treatment with rigid collar, and one patient had a C2-C3 osteophyte with dysphagia. The intraoperative time needed for reaching the retropharyngeal space was 15 (first case), 9 (second case), 7 min (third case-illustrative case-and fourth case), 8 min (fifth case). No complications occurred.

CONCLUSION

Our simplification, avoiding several steps, is simple, effective, safe, and rapid and requires a simple learning curve.

Transcervical approach with endoscopic assistance for surgical treatment of patient with irreducible atlantoaxial dislocation: a case report

We demonstrate the case of a surgery in a patient with irreducible atlantoaxial dislocation (IrAAD) after C2 fracture. The challenges of this case were the flexed head in a forced position, impossibility of neck extension, and revision operation after posterior occipito-cervical fixation. The patient underwent the following surgeries: 1. A ventral release of C1-C2 using transcervical endoscopy; 2. Removal of occipito-cervical system and fibrous block resection in the posterior surfaces of the C1-C2; 3. Reducing of AAD and odontoid screw fixation; 4. Posterior C1-C2-C3 screw fixation. Ankylosing of C1-C2 and C2-C3-C4 fusion was verified by computed tomography scan. There was an improvement in patient status as observed by the increase of the SF-36 scale scores. The use of endoscopic transcervical approach is a good alternative to the transoral approach. Comparative studies of these methods should be performed regarding the choice of an optimal method of decompression in cases of IrAAD.

Comparison of imaging parameters pre- and post- reductive procedure for atlantoaxial dislocation via posterior fixation using pedicle screw and rod: a cross-sectional study

Background

To compare the imaging parameters pre- and post- reductive procedure for atlantoaxial dislocation via posterior fixation using pedicle screw and rod.

Methods

Thirty-seven patients suffering from atlantoaxial dislocation underwent posterior reduction and internal fixation by pedicle screw and rod. We measured pre-operative and post-operative atlantodental interval (ADI), clivus-canal angle (CCA), cervicomedullary angle (CMA), sum of lateral mass interspace (SLMI) of the operation and the control group. ADI, CCA, CMA, and SLMI between the pre-operative and post-operative conditions of the operation group and the control group were compared.

Results

The ADI, CCA, CMA, and SLMI in the pre-operative condition of the operation group were 8.3 ± 4.3 mm, 130.2 ± 14.2°, 133.8 ± 16.7°, and 3.7 ± 1.3 mm, respectively, those in the post-operative condition of the operation group were 1.0 ± 0.9 mm, 148.5 ± 9.4°, 156.0 ± 8.2°, and 8.0 ± 2.7 mm, respectively, while those in the control group were 1.2 ± 0.3 mm, 152.7 ± 5.3°, 160.2 ± 6.3°, and 4.5 ± 1.0 mm respectively. Post-operative ADI, CCA, CMA, and SLMI were statistically different (p < 0.01) from pre-operative assessments. The SLMI has no significant difference between the pre-operative condition and the control group. Post-operative SLMI was statistically different from that of the control group.

Conclusions

The lateral mass joints were widened after the anatomical reduction of atlantoaxial dislocation by pedicle screw and rod. Widening of the lateral mass exists in both atlantoaxial fusion and occipital-cervical fusion.

Traumatic Chronic Irreducible Atlantoaxial Rotatory Fixation in Adults: Review of the Literature, With Two New Examples

Atlantoaxial rotatory fixation (AARF) is a rare condition in adults and is almost always due to an accompanying trauma. The first example of traumatic AARF in adults was reported by Corner in 1907 and since then only 55 adult cases with this rare traumatic scenario have been published so far. Approximately 80% of adults with traumatic AARF are diagnosed soon after the traumatic events. However, in the remaining casualties, the condition might be missed with some delay from the diagnosis to treatment. If this pathology is diagnosed early enough, the conservative attempts for a closed reduction are usually effective. After closed reduction, external immobilization is required to prevent recurrence of the dislocation. However, with delayed diagnosis, the condition may remain refractory to traction on manipulation and require an open reduction instead. In the literature, such irreducible chronic AARFs are rarely reported, being confined to only 14 adult examples, in whom surgical intervention for correction of the deformity will be required. In such cases, release of the atlantoaxial facet joints is the first surgical step. In the subsequent step, reduction of the dislocated facet joints can be done via one of the already described maneuvers. As the final step, C1-C2 fixation will be necessary for prevention of re-dislocation. Herein, 2 adult patients with chronic rotatory atlantoaxial dislocation of traumatic origin are presented. In both cases, cranial traction and manipulations were ineffective and therefore an open reduction procedure was proposed and accomplished via the posterior midline corridor. The transverse rod technique was implemented subsequent to the atlantoaxial facet release. After correction of the deformity, a C1-C2 fixation was accomplished followed by arthrodesis. In addition to the outlined procedure, an historical review of the literature on this subject from the beginning of 20th century is demonstrated.

The Value and Limitation of Cervical Traction in the Evaluation of the Reducibility of Atlantoaxial Dislocation and Basilar Invagination Using the Intraoperative O-Arm

OBJECTIVE

To assess the value and limitation of cervical traction in the evaluation of the reducibility of atlantoaxial dislocation (AAD) and basilar invagination (BI) using the intraoperative O-arm.

METHODS

A total of 22 patients with hyperextensive, irreducible AAD were included. The cervical traction test under general anesthesia was performed, and the degree of reduction was evaluated using the O-arm before the operation started. The traction effects both vertically and horizontally were evaluated. All cases then underwent modified direct posterior reduction and fixation. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scale. Radiologic measurements included the anterior atlantodental interval, the distance of odontoid tip above Chamberlain line, and the clivus-canal angle. Magnetic resonance imaging signal changes, size of syringomyelia, and the space ventral to medulla also were used to evaluate the postoperative reduction result.

RESULTS

After the cervical traction test, 7 patients achieved incomplete reduction, 5 achieved only vertical reduction, 6 achieved only horizontal reduction, and 4 achieved complete reduction in both horizontal and vertical orientations as assessed by the O-arm. All patients underwent a direct reduction technique. The mean JOA score increased from 11.1 to 14.5. Complete reduction of AAD and BI were achieved in 19 patients (86.4%), with partial reduction achieved in 3 (13.6%). Sufficient cerebrospinal fluid space anterior to the medulla with improved JOA score was achieved in the 3 partially reduced patients.

CONCLUSIONS

With the innovations of direct posterior reduction techniques, cervical traction under anesthesia may not sufficiently predict the reducibility of BI and AAD. Cervical traction still plays an important role during the direct posterior reduction procedure.

Endoscopic transnasal anterior release and posterior reduction without odontoidectomy for irreducible atlantoaxial dislocation

Background

To investigate the efficacy and safety of endoscopic transnasal anterior release and posterior reduction without odontoidectomy to treat irreducible atlantoaxial dislocation (IAAD).

Methods

A series of 9 patients with IAAD underwent endoscopic transnasal anterior release and posterior reduction without odontoidectomy. Etiology, instrumentation, fusion rate, and complications were documented. All patients were assessed clinically and radiologically for neurological recovery using the Japanese Orthopedic Association (JOA) score, atlantodontoid interval (ADI), and cervicomedullary angle (CMA).

Results

The mean age of the patients was 41.6 years, ranging from 14 to 60 years. Pathology showed os odontoideum in 3 patients, old traumatic dens fracture in 3 patients, occipitalization of C1 in 2 patients, and rheumatoid arthritis in 1 patient. Seven patients underwent C1–C2 pedicle screw fixations, and 2 patients required occipitocervical fixation. Eight cases resulted in complete reduction and 1 in partial reduction. Complications included one superficial infection related to the posterior approach. All patients were followed up for an average of 17 (range 13–32) months. Bony fusion was confirmed in all cases under radiologic assessment at 1 year postoperatively, and the bony fusion rate reached 100%. Moreover, no instrumental failure occurred during the entire follow-up period. The JOA score improved from 7.21 ± 1.62 to 12.28 ± 0.81 at the last follow-up. The ADI of 9 cases was 7.06 ± 0.85 mm preoperatively, which decreased to 2.26 ± 0.56 mm at the final follow-up. CMA improved from 103.80° ± 4.16° to 143.23° ± 7.47° postoperatively.

Conclusion

With transnasal approach and lack of odontoidectomy, this method could not only treat IAAD safely and effectively, but also reduce the possibility of many complications associated with the traditional transoral approach and odontoidectomy.

[Atlantoaxial joint release through anterior retrophayngeal approach and staged posterior reduction fixation and fusion for irreducible atlantoaxial dislocation]

Objective

To discuss the effectiveness of atlantoaxial joint release through anterior retrophayngeal approach and staged posterior reduction fixation and fusion for irreducible atlantoaxial dislocation (IAAD).

Methods

Fifteen patients with IAAD (9 males, 6 females), aged 14-53 years (mean, 31.4 years) were included in the study. The disease duration was 3 months to 17 years (mean, 5.7 years). IAAD was attributed to trauma in 13 cases, and 2 cases were caused by congenital odontoid disconnection. Preoperative imaging examination showed atlantoaxial dislocation and could not be reset automatically in functional position. The preoperative visual analogue scale (VAS) score was 3-7 (mean, 4.1), and the preoperative Japanese Orthopaedic Association (JOA) score was 10-17 (mean, 13.8). All patients received atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion.

Results

Anatomical reduction was achieved in all 15 patients, and the alignment of atlantoaxial joints was restored. After operation, the neck pain and neurological symptom were partially or fully improved in all patients, without deterioration of neurological function. One patient developed pharyngeal discomfort and cough after one-stage operation, 4 patients developed pharyngeal discomfort and foreign body sensation after operation, and 2 patients developed pin-path lipstick swelling during skull traction. All patients were cured by symptomatic treatment. No pulmonary infection, pressure ulcers, venous thrombosis, and incision infection was found during the treatment. All 15 patients were followed up 24-36 months, with an average of 28.6 months. Bony fusion was achieved in all patients, and the fusion time was 3-5 months, with an average of 3.6 months. At last follow-up, the VAS score was 0-2 (mean, 0.5) and the JOA score was 13-17 (mean, 15.9). There was no dislocation, recurrence, or other abnormal sign in the cervical X-ray films and three-dimensional CT.

Conclusion

Anatomical reduction can be achieved by atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion for treating IAAD. It is an optional procedure for IAAD.

Anterior submandibular retropharyngeal odontoid osteotomy and posterior atlantoaxial fusion for irreducible atlantoaxial dislocation associated with odontoid fracture malunion

PURPOSE

To report a case of complex odontoid fracture malunion accompanied by atlantoaxial dislocation which was treated with a new surgical approach.

METHODS

A 53-year-old female was admitted due to progressive symptoms with a stiff limp and unsteady gait. Preoperative examination, diagnostic radiography, computed tomography, and magnetic resonance imaging were performed following admission. The examinations showed odontoid fracture malunion, an old right axial zygapophyseal fracture, atlantoaxial dislocation, and spinal cord injury. Anterior submandibular retropharyngeal odontoid osteotomy and posterior atlantoaxial fusion were then performed.

RESULTS

Good reduction of the atlantoaxial dislocation was gained. The cervical spinal cord compression was significantly relieved and neurological function was also significantly improved.

CONCLUSION

Anterior submandibular retropharyngeal odontoid osteotomy and posterior atlantoaxial fusion fixation is an effective method for treating IAAD associated with odontoid fracture malunion, it avoids the adverse effects of anterior transoral odontoid osteotomy and provides a new option for the treatment of odontoid fracture malunion associated with atlantoaxial dislocation.

Irreducible Atlanto-Axial Dislocation in Neglected Odontoid Fracture Treated with Single Stage Anterior Release and Posterior Instrumented Fusion

It is a well-know fact that type 2 odontoid fractures frequently go into nonunion. If left untreated, patients may develop irreducible atlantoaxial dislocation (AAD). We describe the surgical management of two patients with neglected odontoid fractures and irreducible AAD treated with single stage anterior release followed by posterior instrumented fusion. Both patients presented with history of neglected trauma and progressive myelopathy. Traction under anesthesia failed to achieve reduction of AAD. Anterior release was done by trans-oral approach in one patient and retrophayngeal approach in the other. Posterior fixation was performed with transarticular screws in both the patients. Both patients had full neurological recovery and demonstrated fusion at follow-up. Anterior release followed by posterior instrumented correction may be an effective alternative to the traditional means of treating irreducible dislocations associated with neglected odontoid fractures.

Modified technique of transoral release in one-stage anterior release and posterior reduction for irreducible atlantoaxial dislocation

BACKGROUND

One-stage anterior release and posterior reduction is one of the most effective methods for irreducible atlantoaxial dislocation. However, the criteria of appropriate tissue release for successful posterior reduction is yet to be confirmed. Hence, an assistant technique using the transoral approach to verify satisfactory release is required. To evaluate the efficacy of the modified technique of transoral release for irreducible atlantoaxial dislocation (IAAD) with patients underwent one-stage anterior release and posterior reduction.

METHODS

Between January 2009 and June 2014, 23 consecutive patients diagnosed with IAAD free from bony union between the C1-C2 facet joints on reconstructive computed tomography scan underwent one-stage anterior release and posterior reduction after no response to 2 weeks of skull traction. During transoral release, an elevator was used as a lever repeatedly to confirm a 3-5 mm bilateral joint space between the lateral masses of the atlas and axis. The release was accomplished since a 3-5 mm joint space was achieved. After anterior release, posterior reduction and instrumented fusion were subsequently performed.

RESULTS

All patients were observed for an average of 18 (range 6-50) months. Nineteen of 23 patients achieved complete reduction while four had an incomplete reduction. Significant differences in pre- and postoperative JOA scores and cervicomedullary angle (CMA) were found. Twenty-one patients presenting with myelopathy had a JOA score of 12.9 at final follow-up, improved from 7.8 before surgery. The mean CMA improved to 143.5° postoperatively from 101.8° preoperatively. Bony fusion was confirmed in all cases under radiologic assessment during follow-up; there were no instrument failures.

CONCLUSION

The modified technique of transoral release provides appropriate criteria for anterior release, to achieve good posterior reduction without excessive tissue release or intraspinal manipulation, proving its value as an assistant technique in one-stage anterior release and posterior reduction for IAAD.