Is anterior release and cervical traction necessary for the treatment of irreducible atlantoaxial dislocation? A systematic review and meta-analysis

Posterior Release, Reduction, and Intra-Articular Fusion for Irreducible Type III Atlantoaxial Rotary Fixation

BACKGROUND AND OBJECTIVES

For irreducible atlantoaxial rotary fixation (AARF), anterior or posterior release was often needed before posterior reduction and fusion. Anterior atlantoaxial joint release has potential complications such as retropharyngeal abscess, persistent hoarseness, and infection. This study aims to assess the efficacy of posterior release, reduction, and intra-articular fusion without resecting the C2 nerve root on irreducible type III AARF.

METHODS

The data of 9 pediatric patients diagnosed with AARF who underwent posterior atlantoaxial release, reduction, and intra-articular fusion without resecting the C2 nerve root were retrospectively reviewed. Japanese Orthopaedic Association scores and Visual Analog Scale for Neck Pain were used to assess outcomes. The preoperative and follow-up assessments of atlantodens interval (ADI) were documented to evaluate the reduction of atlantoaxial joint. The patient demographics, surgery time, blood loss, bone fusion time, follow-up period, and surgery-related complications were meticulously documented.

RESULTS

The mean follow-up duration was 35.1 ± 11.5 months. Complete reduction was achieved in 8 patients, while one patient did not achieve complete reduction. The ADI decreased significantly from 8.7 ± 2.2 mm before surgery to 2.1 ± 1.3 mm at the final follow-up. All patients demonstrated successful bone fusion, with an average fusion period of 3.7 ± 1.3 months. The Visual Analog Scale for Neck Pain at the final follow-up exhibited a significant decrease compared with preoperative values (P < .05), while no significant difference was observed in Japanese Orthopaedic Association scores. There were no complications related to surgery.

CONCLUSION

Posterior atlantoaxial release, reduction, and intra-articular fusion with a C2 nerve root preservation technique is effective in the treatment of irreducible type III AARF.

Efficacy of a Lateral Mass Fusion Device Combined with a Three-Dimensional-Printed Model in the Treatment of Craniovertebral Junction Abnormalities

OBJECTIVE

To investigate the efficacy of a lateral mass fusion device combined with a three-dimensional-printed model in treatment of craniovertebral junction abnormalities.

METHODS

This retrospective study comprised 56 patients with irreducible atlantoaxial dislocation who underwent posterior fixation between January 2016 and December 2019. Patients were divided into 2 groups according to whether or not cages were used-cage group and autograft group. Visual analog scale score, Japanese Orthopaedic Association score, health-related quality of life, American Spinal Injury Association spinal cord injury grade, atlas-dens interval, space available for the cord, cervicomedullary angle, and fusion rate were compared between groups.

RESULTS

Medical follow-up was >1 year. There was no statistical difference between groups in preoperative visual analog scale score, Japanese Orthopaedic Association score, 12-Item Short Form Health Survey score, American Spinal Injury Association grade, atlas-dens interval, space available for the cord, and cervicomedullary angle, and these indexes significantly improved after surgery (P < 0.05). Visual analog scale score and atlas-dens interval were lower in the cage group than in the autograft group (P < 0.05). Japanese Orthopaedic Association score, 12-Item Short Form Health Survey score, space available for the cord, and cervicomedullary angle were significantly higher in the cage group than in the autograft group (P < 0.05). Fusion rate of the cage group 4-6 months after surgery was higher than that of the autograft group (P = 0.068). American Spinal Injury Association grade was significantly higher in the cage group than in the autograft group (P < 0.05).

CONCLUSIONS

During 1-year follow-up, neurological function improvement and atlantoaxial joint reduction were satisfactory. The lateral mass fusion device combined with a three-dimensional printed model may be a clinically useful technique.

The management of neglected spondylitis tuberculosis with dislocated C1 and C2 odontoid destruction: A case report

INTRODUCTION AND IMPORTANCE

Spinal tuberculosis was the most common TB infection in human body. Musculoskeletal tuberculosis (TB) mostly affected lower thoracal or upper lumbar spine. However, TB infection can also occurs along vertebral spine. We reported a rare case about TB infection in cervical spine. We provided the clinical manifestation and therapeutic method for the patient. Cervical TB infection is a very rare case. Especially, when it involves in C1 and C2 like we provided on this case.

CASE PRESENTATION

A 24 years-old male came to the orthopaedic clinic with neck pain that aggravated by neck movement. He previously diagnosed with TB infection on his lung within 3 months. We performed x-ray data to determine the source of neck pain. Examination revealed anterior collapse of C1, destruction of odontoid process, and soft tissue swelling. We also performed MRI cervical to assess the destruction of anterior corpus C1.

CLINICAL DISCUSSION

We decided to operate the patient with reposition and posterior stabilization of C1 using occipital plate from posterior approach and added some synthetic bone graft. The medical treatment is anti-tuberculosis drugs, usually conducted conservatively in mild-to-moderate cases. But, if there is deterioration in neurological deficit or persisting deficit with spinal cord compression, such as C1 and C2 involvement, surgery can be considered. There are two types of surgery; posterior fixation and fusion and anterior release and posterior stabilization.

CONCLUSION

TB musculoskeletal infection must be evaluated regularly to consider the perfect time for additional surgical treatment. The good decision to operate the moderate to severe case could improve the patient's functional outcome.

Quantitative Reduction of Basilar Invagination: Correction Target of Clivo-Axial Angle

STUDY DESIGN

A mechanism-based reasoning and case-control study.

OBJECTIVE

To introduce correction target of clivo-axial angle (CXA) in quantitative surgical reduction of basilar invagination (BI).

SUMMARY OF BACKGROUND DATA

The exact mechanism of BI with or without atlantoaxial dislocation is still unclear. Sagittal deformity is a key feature of BI. Correction of CXA directly influences subaxial cervical lordosis (increase of CXA equals the decrease of cervical lordosis). However, a quantitative reference for correction surgery has not been established.

MATERIALS AND METHODS

CXA was divided by Chamberlain line into clivus tilt (CT) and axial tilt (AT). Patients diagnosed with BI were retrospectively included. Patients with degenerative cervical spine diseases or vascular diseases (without BI) were included as controls. CT, AT, and other common parameters were measured and analyzed with t test and multiple linear regression. Demonstration case was presented.

RESULTS

A total of 42 BI patients and 23 controls were included. Normal references for CXA, AT, and CT were 162.3±7.1, 93.8±6.5, and 68.6±3.8 degrees, respectively. BI patients had a 30.3-degree smaller CXA, a 15.5-degree smaller AT, and a 14.9-degree smaller CT. Basal angle (P=0.002) independently had a significant influence on extent of BI, while CT and AT did not. Demonstration case showed that CT was fixed and correcting AT to an ideal 94 degrees was optimal for an individual patient.

CONCLUSIONS

Proper quantitative correction of CXA needs to be individualized in consideration of CT and AT. The difference between actual AT and its ideal value (about 94 degrees) is the optimal target of CXA correction to decompress neural elements ventrally and recover better subaxial cervical lordosis.

LEVEL OF EVIDENCE

Level IV.

Critically Low Confidence in the Results Produced by Spine Surgery Systematic Reviews: An AMSTAR-2 Evaluation From 4 Spine Journals

STUDY DESIGN

A systematic cross-sectional survey of systematic reviews (SRs).

OBJECTIVE

To evaluate the methodological quality of spine surgery SRs published in 2018 using the updated AMSTAR 2 critical appraisal instrument.

METHODS

We identified the PubMed indexed journals devoted to spine surgery research in 2018. All SRs of spine surgical interventions from those journals were critically appraised for quality independently by 2 reviewers using the AMSTAR 2 instrument. We calculated the percentage of SRs achieving a positive response for each AMSTAR 2 domain item and assessed the levels of confidence in the results of each SR.

RESULTS

We identified 28 SRs from 4 journals that met our criteria for inclusion. Only 49.5% of the AMSTAR 2 domain items satisfied the AMSTAR 2 criteria. Critical domain items were satisfied less often (39.1%) compared with noncritical domain items (57.3%). Domain items most poorly reported include accounting for individual study risk of bias when interpreting results (14%), list and justification of excluded articles (18%), and an a priori establishment of methods prior to the review or registered protocol (18%). The overall confidence in the results was rated "low" in 2 SRs and "critically low" in 26.

CONCLUSIONS

The credibility of a SR and its value to clinicians and policy makers are dependent on its methodological quality. This appraisal found significant methodological limitations in several critical domains, such that the confidence in the findings of these reviews is "critically low."

Anterior decompression through transoral axis slide and rotation osteotomy for salvage of failed posterior occipitocervical fusion: a novel technique note

Atlantoaxial dislocation could be caused by odontoid fractures or Os odontoideum. The previous surgical techniques in treatment of atlantoaxial dislocation were based on arch remove decompression or anterior atlantoaxial release and atlantoaxial (occipital-cervical) screw fixation-based reduction and fusion. However, for some clinical situations, all of above techniques cannot be applied. In this study, a patient with atlantoaxial dislocation caused by Os odontoideum treated by posterior occipitocervical fusion 20 years ago and failed. We design a novel anterior decompression through transoral axis slide and rotation osteotomy for salvage of this failed posterior occipitocervical fusion case. The C2 body and odontoid process was ventrally slide and rotation at good position after operation as well as the position of plate and screws, the spinal canal was increased significantly after operation too. We suggest this anterior decompression through transoral "C2 slide and rotation" technique is good choice for salvage of failed posterior occipitocervical fusion and some irreducible atlantoaxial dislocation because of the anterior bony fusion, it could direct decompress the spinal cord anteriorly, avoid the odontoid resection, and is feasible and safe technique.

Effectiveness of posterior reduction and fixation in atlantoaxial dislocation: a retrospective cohort study of 135 patients with a treatment algorithm proposal

PURPOSE

Surgical procedures on atlantoaxial dislocation remain controversial. The aim of this observational retrospective study was to investigate the treatment algorithm of surgical procedures.

METHODS

According to CT and intraoperative evaluation during direct posterior reduction, 135 AAD cases were categorized into three groups: Group I: reducible dislocation; Group II: irreducible dislocation (Group IIa: effective decompression achieved after posterior reduction; Group IIb: no effective decompression after posterior reduction); and Group III: fixed dislocation. Group III presented with extensive bony fusions. Group I and Group IIa were treated with direct posterior reduction and fixation. Group IIb underwent posterior fixation and transoral odontoidectomy. Group III underwent transoral odontoidectomy alone. Japanese Orthopedic Association scores (JOA) were assessed to evaluate clinical status before and 6, 12 months after surgery.

RESULTS

Our study included 118 Group I cases, 16 Group II cases (Group IIa: 11 cases; Group IIb: 5 cases), and one Group III case. Follow-up ranged from 12 to 36 months.

PRIMARY OUTCOME

Anatomic atlantoaxial reduction was achieved in 118 of 135 patients (87.4%). Clinical improvements were seen in 96.3% (130/135) all the patients. Solid atlantoaxial fusion was shown in 134 patients. Secondary outcome: The overall complication rate was 3.7% (5/135). For Group I, the mean postoperative 6-month JOA was 14.5 versus 12.2 in preoperative patients (paired Student's t test, P < 0.01).

CONCLUSIONS

This article proposes a clinical procedure that assists with therapeutic decision making and indicates the severity and difficulty of reduction of the atlantoaxial joint. These slides can be retrieved under Electronic Supplementary Material.

The use of intraoperative traction for achieving reduction of irreducible atlantoaxial dislocation caused by different craniovertebral junction pathologies

OBJECTIVE

To investigate the usefulness of intraoperative traction in the selection of the surgical procedure for irreducible atlantoaxial dislocation (IAAD) caused by different craniovertebral junction (CVJ) pathologies.

PATIENTS AND METHODS

Forty-three patients who were diagnosed with IAAD and who underwent surgery between January 2008 and May 2017 in our hospital were included in the study. All of the patients received skull traction under general anesthesia. Based on the traction results, the patients underwent one of the following surgeries: posterior fixation and fusion only, posterior atlantoaxial lateral mass joint release followed by fixation and fusion, or anterior release followed by posterior fixation and fusion. The classification system was defined accordingly. The treatment efficacy was evaluated based on the improvement of clinical symptoms and radiological findings.

RESULTS

Four patients were categorized as Type A, twenty patients as Type B1, twelve patients as Type B2, and seven patients as Type C. Thirty-seven patients (86.0%) achieved complete reduction and six patients (14.0%) achieved greater than 50% reduction. Bony fusion was achieved in all patients at 6 months after the operation. The average Japanese Orthopaedic Association (JOA) score improved from 10.2 ± 2.1 before surgery to 15.0 ± 1.2 at the final follow-up. According to the Symon clinical standard, the total effectiveness rate was 97.7%, and 72.1% of the patients showed excellent clinical outcomes.

CONCLUSION

Intraoperative traction is an effective and safe method to assist the selection of surgical methods for patients with IAAD caused by different CVJ etiologies.