Release, reduction, and fixation of one-stage posterior approach for basilar invagination with irreducible atlantoaxial dislocation

PURPOSE

We evaluate the efficacy, safety and indications of single stage posterior release, reduction, and fixation of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD).

MATERIALS AND METHODS

Seventeen patients with BI and IAAD consecutively underwent one-stage release, reduction, and fixation by a posterior approach from July 2000 to June 2015 were followed up for at least 12 months. There were 8 males. Mean age was 56 35.2 ± 13.8 years (range 12-56). The clinical symptoms and signs of the patients were recorded. Pre- and postoperative imaging examinations were performed. Neurological function was assessed using the Japanese Orthopedic Association (JOA) and Ranawat scores.

RESULTS

Average follow-up time was 47.4 months (12-97 months). The JOA score increased from preoperative 4-10 (8.06 ± 2.52) to postoperative 13-16 (15.20 ± 0.62). The preoperative Chamberlain line, McRae line, Wackenheim line, atlantodens interval, and cervico medullary angle were 12.52 ± 5.17 mm, 6.59 ± 3.04 mm, 6.96 ± 4.32 mm, 9.88 ± 1.93 mm, and 115.35 ± 12.40°, respectively. The postoperative values were 2.0 ± 3.67 mm, -3.06 ± 1.85 mm, -1.76 ± 2.88 mm, 1.17 ± 1.18 mm, and 136.76 ± 11.44°, respectively.

CONCLUSION

One-stage release, reduction, and fixation for patients with BI and IAAD through a posterior approach is safe and efficient.

A novel surgical management for pediatric patients with irreducible atlantoaxial dislocation: Transoral intraarticular cage distraction and fusion with C-JAWS staple fixation

Background

Currently, irreducible atlantoaxial dislocation (IAAD) can be treated by a single transoral approach in one stage to reduce surgical injuries to patients. However, the widely used fixation devices are not suitable for pediatric patients because of larger profile of devices.

Objective

The purpose of this study is to report the preliminary clinical outcomes of a novel surgical technique by transoral intraarticular cage distraction and fusion with C-JAWS staple fixation for pediatric patients with IAAD.

Methods

From June 2011 to June 2014, eight pediatric patients with IAAD were enrolled and treated by this technique in our department. Patients' clinical data were retrospectively analyzed, including neurological status, clinical symptoms, reduction, bone fusion, and complications.

Results

The surgeries were successfully performed in all patients without injuries to spinal cord, nerve and blood vessel. Clinical symptomatic relief was presented on all 8 patients (100%). Satisfactory reduction was indicated by significant decrease of atlanto-dental interval postoperatively (P < 0.05). The remarkable improvement of postoperative neurological function has been proved by significant increase of Japanese Orthopaedic Association score (P < 0.05). The average follow-up duration was 19.4 ± 5.8 months (range 12-30 months). Bone fusion was achieved in all 8 cases. No complications were documented after operation and during follow-up.

Conclusions

Transoral intraarticular cage distraction and fusion with C-JAWS staple fixation is an effective treatment for pediatric patients with IAAD, which can achieve satisfactory reduction, fixation and bone 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 and Anterior Reconstruction for a Neglected Osteoporotic Odontoid Fracture

A 70 years old lady presented to us with history of a fall 3 months prior. She had suffered a type 2 odontoid fracture with atlantoaxial dislocation, that was not reducible by traction. She had symptoms of neck pain with inability to hold the neck upright. The patient was subsequently planned for anterior release and reduction of odontoid fracture dislocation with posterior stabilization in the same sitting. The patient was treated with cervical skeletal traction and immobilized. However, she developed occipital sore during the period and was mobilized with brace after which she developed myelopathic symptoms and gait disturbance due to the collapse of fracture segment. The patient was planned for anterior release and fixation with contoured reconstruction plate fixing C1 lateral mass to the lateral mass on the right side and C1 lateral mass to C2 body on the left side primarily with distraction of the C1-C2 joint by autologous tricortical iliac bone graft. The posterior stabilization was planned after healing of the sore, and the patient was counseled for the same. However, the patient was lost on follow-up and returned at 3-month postoperative period with collapse of the graft, resubluxation of C1-C2 segment, and failure of anterior fixation. The standard modality of treatment for such cases includes an anterior release of contracted soft tissues and ligaments and posterior stabilization with fusion in a single setting. However, it is the posterior fixation that stabilizes the fracture and prevents it from redislocation. Anterior fixation as a stand-alone treatment in osteoporotic bone has high risks of failure due to severe posterior tensile stresses. This article describes the importance of posterior fixation in osteoporotic bone based on our experience.

Sagittal Atlantoaxial Joint Inclination and Reduction Index Values for Diagnosis and Treatment of Irreducible Atlantoaxial Dislocation

BACKGROUND

Irreducible atlantoaxial dislocation (IAAD) is a disorder of atlantoaxial joint instability with various causes. The diagnostic criteria for IAAD are variable. The diagnosis of IAAD is mainly based on preoperative and intraoperative traction results, as well as the physician's experience, with no relatively uniform guidelines for the selection of treatment. This study evaluates sagittal atlantoaxial joint inclination (SAAJI) and reduction index (RI) values for diagnosis and treatment of IAAD.

MATERIALS AND METHODS

24 IAAD patients treated in our hospital from January 2008 to July 2014 were retrospectively analysed. Patients included were 13 males and 11 females, with a mean age of 43 years. The various causes for IAAD were atlantoaxial transverse ligament rupture (n=3), old dens fracture (n=15), occipitalization of the atlas (n=6). The patients were divided into two groups. group A underwent anterior release with posterior reduction and fixation; Group B underwent posterior reduction and fixation; 12 healthy individuals served as controls. SAAJI and atlas-dens interval (ADI) values before and after traction were measured, and RI was calculated. Imaging data were analyzed.

RESULTS

The mean SAAJI values were as follows: left, 5.6 ± 1.9° and right, 5.1 ± 2.1° in the control group; right, 39.5 ± 6.0° and left, 38.8 ± 5.8° in Group A; and right, 23.1 ± 7.0° and left, 23.9 ± 6.1° in Group B. There was no significant difference in the SAAJI values of the three groups (P < 0.05). The mean RIs in Groups A and B were 17.6 ± 9.3% and 34.4 ± 5.2%, respectively, and the difference was statistically significant (P < 0.05). There were obvious negative correlations between the SAAJI and RI values in Groups A and B.

CONCLUSIONS

SAAJI and RI can be used as important imaging indicators to determine the reversibility of IAAD. If the RI value is >27.9% and SAAJI value is <32.5°, reduction and fixation can be achieved by the posterior approach alone; otherwise, a combination of anterior and posterior approaches would be necessary.

Comprehensive drilling of the C1-2 facets to achieve direct posterior reduction in irreducible atlantoaxial dislocation

OBJECT

The cause of irreducibility in irreducible atlantoaxial dislocation (AAD) appears to be the orientation of the C1-2 facets. The current management strategies for irreducible AAD are directed at removing the cause of irreducibility followed by fusion, rather than transoral decompression and posterior fusion. The technique described in this paper addresses C1-2 facet mobilization by facetectomies to aid intraoperative manipulation.

METHODS

Using this technique, reduction was achieved in 19 patients with congenital irreducible AAD treated between January 2011 and December 2013. The C1-2 joints were studied preoperatively, and particular attention was paid to the facet orientation. Intraoperatively, oblique C1-2 joints were opened widely, and extensive drilling of the facets was performed to make them close to flat and parallel to each other, converting an irreducible AAD to a reducible one. Anomalous vertebral arteries (VAs) were addressed appropriately. Further reduction was then achieved after vertical distraction and joint manipulation.

RESULTS

Adequate facet drilling was achieved in all but 2 patients, due to VA injury in 1 patient and an acute sagittal angle operated on 2 years previously in the other patient. Complete reduction could be achieved in 17 patients and partial in the remaining 2. All patients showed clinical improvement. Two patients showed partial redislocation due to graft subsidence. The fusion rates were excellent.

CONCLUSIONS

Comprehensive drilling of the C1-2 facets appears to be a logical and effective technique for achieving direct posterior reduction in irreducible AAD. The extensive drilling makes large surfaces raw, increasing fusion rates.