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

Tang, Xiuwen; Wu, Xianguo; Tan, Mingsheng; Yi, Ping; Yang, Feng; Hao, Qingying

doi:10.1186/s13018-019-1167-0

Cited by 10 publications

(8 citation statements)

References 30 publications

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“…Operative release and the pedicle screw technique have been able to achieve reduction in the dislocated atlantoaxial joint when traction reduction has been unsuccessful. [13][14][15] Therefore, considering operative release, the technique of three-dimensional CT and traumatic factors, we should distinguish atlantoaxial dislocations that can be reduced surgically from the others. In the present study, our TOI classification system is able to do that.…”

Section: Discussionmentioning

confidence: 99%

New Classification and Its Value Evaluation for Atlantoaxial Dislocation

Tan

Long

et al. 2020

Orthopaedic Surgery

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Objective To introduce the TOI classification system (the Traction reduction type [T type], Operation reduction type [O type], and Irreducible type [I type] classification system) and to determine the interobserver and intraobserver reliability of the TOI classification system. Methods Based on the characteristics of atlantoaxial dislocation (AAD), AAD was divided into Traction reduction type (T type), Operation reduction type (O type), and Irreducible type (I type). The analysis of interobserver and intraobserver agreements was done using kappa statistics. From July 2016 to January 2019, 213 AAD patients were retrospectively studied at four hospitals. Plain radiographs including extension and flexion views and three‐dimensional CT images were obtained. Twenty independent observers, including eight experienced spine specialists and 12 orthopaedic fellows from four different residency training hospitals, completed the survey. Results The classification of the TOI system was based on etiology, the course of the disease, flexion–extension X‐rays, three‐dimensional CT reconstruction, and curative effects of skull traction. Flexion–extension X‐rays demonstrating a successful reduction of the dislocated atlantoaxial joint and three‐dimensional CT images showing osseous fusion of atlantoaxial facet joints and cervical traction reveal characteristics of T‐type. Furthermore, this type can be divided into two subtypes, T1 and T2, according to the etiology and course of the disease. Unsatisfactorily reduction after 1–2 weeks of strict cervical traction, no reduction shown on flexion–extension X‐rays, and no destruction or boneless fusion of atlantoaxial facet joints demonstrated in three‐dimensional CT images are characteristics of type O. Atlantoaxial facet joint showing bone fusion or failure of reduction after cervical traction or three‐dimensional CT images showing failure of surgical release are characteristics of type I. Interobserver and intraobserver reliability of the TOI classification system were moderate (κ = 0.543) and substantial (κ = 0.658), respectively. Interobserver and intraobserver reliability of the treatment choice were moderate (κ = 0.568) and substantial (κ = 0.675), respectively. There were no significant differences in the interobserver and intraobserver reliability between experienced spine specialists and fellows for all κ‐values (P > 0.05). Conclusions The TOI classification system had satisfactory reliability and, therefore, can be applied clinically and used by less experienced surgeons. We believe TOI can help surgeons choose appropriate treatment strategies.

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Section: Discussionmentioning

confidence: 99%

New Classification and Its Value Evaluation for Atlantoaxial Dislocation

Tan

Long

et al. 2020

Orthopaedic Surgery

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“…In their study, they determined that the majority of IAAD cases could become reducible after anterior release without odontoid resection. Thus, the clinical outcome of traditional treatments for IAAD was relatively satisfactory [18][19][20].…”

Section: Discussionmentioning

confidence: 99%

Retropharyngeal Reduction Plate for Treatment of Irreducible Atlantoaxial Dislocation: A Cadaveric Test and Finite Element Analysis

Zhao

et al. 2020

Preprint

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Background: Clinical studies have shown that irreducible atlantoaxial dislocation (IAAD) can achieve reduction, decompression, fixation and fusion by transoral, posterior, and other traditional approaches. The present study aims to introduced a newly designed reduction plate through the retropharyngeal approach and evaluate its feasibility by cadaveric test and finite element analysis.Methods: A cadaveric specimen and a 45-year-old postoperative female patient diagnosed with IAAD who underwent the traditional posterior fixation were enrolled in this scientific study. The retropharyngeal approach involved placing the reduction plate into a cadaveric specimen’s cervical spine. Spiral CT thinly scanning (0.05 mm) from the base of the occipital bone to C7 vertebrae was performed and reconstructed for three-dimensional (3D) finite element analysis using Mimics software based on the Dicom data of two different fixations. Biomechanical distribution was compared between two fixations under different stress conditions, including flexion, extension, bending and rotation, respectively.Results: There was no significant difference in maximum stress between the retropharyngeal reduction plate system and the posterior atlantoaxial pedicle screw fixation system during flexion. Under states of extension, bending and rotation, the maximum stress of the reduction plate system was significantly lower than that of the posterior atlantoaxial pedicle screw fixation system. Both of the maximum stresses between two fixations were far lower than the maximum yield strength (795-827 MPa) and ultimate strength (860-896 MPa) of the titanium alloys. There was no significantly stress concentration between retropharyngeal reduction plate system and the posterior atlantoaxial pedicle screw fixation system under different movement.Conclusions: The cadaveric test showed that it is feasible to place the reduction plate using the retropharyngeal approach. The finite element analysis indicated that the retropharyngeal reduction plate system may provide relatively reliable fixation compared with traditional posterior fixation. A new choice of designing a surgical plan for treating atlantoaxial dislocation is presented.

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“…As for the transoral approach, the contamination by nasopharyngeal flora has the high risk of causing postoperative infection, and high demand of pre/postoperative oral nursing care. The postoperative nasal feeding and tracheostoma also significantly reduce the quality of a patient's life 25 . Moreover, the anterior release is necessary for further easier reduction and fixation by posterior instrumentation and fusion to some patients with IAAD.…”

Section: Comparison Between Retropharyngeal Reduction Plate and Diffe...mentioning

confidence: 99%

Retropharyngeal Reduction Plate for Atlantoaxial Dislocation: A Cadaveric Test and Morphometric Trajectory Analysis

Meng

et al. 2022

Orthopaedic Surgery

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Objective: To evaluate the placement feasibility and safety of the newly designed retropharyngeal reduction plate by cadaveric test and to perform morphometric trajectory analysis. Methods:The five cadaveric specimens with intact atlantoaxial joint were enrolled in this study. They were used for simulating the placement process and evaluating the placement feasibility of the retropharyngeal reduction plate. The atlantoaxial dislocation (AAD) of five cadaveric specimens were obtained by proper external force after dissecting ligaments. The retropharyngeal reduction plate was placed on atlantoaxial joint of cadaveric specimens. The X-ray and three-dimensional (3D) spiral CT were used for evaluating the placement safety of retropharyngeal reduction plate. The DICOM data was obtained after 3D spiral CT scanning for the morphometric trajectory analysis. Results:The reduction plates were successfully placed on the atlantoaxial joint of five cadaveric specimens through the retropharyngeal approach, respectively. The X-ray and 3D spiral CT showed the accurate screw implantation and satisfying plate placement. The length of the left/right atlas screw trajectory (L/RAT) was, respectively, 1.73 AE 0.01 cm (LAT) and 1.71 AE 0.02 cm (RAT). The length of odontoid screw trajectory (OST) was 1.38 AE 0.02 cm. The length of the left/right axis screw trajectory (L/RAXT) was, respectively, 1.67 AE 0.02 cm (LAXT) and 1.67 AE 0.01 cm (RAXT). There was no statistical significance between left side and right side in terms of AT and AXT (P > 0.05). The angles of atlas screw trajectory angle (ASTA), axis screw trajectory angle (AXSTA), and odontoid screw trajectory angle (OSTA) were 38.04

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

Cited by 10 publications

References 30 publications

New Classification and Its Value Evaluation for Atlantoaxial Dislocation

New Classification and Its Value Evaluation for Atlantoaxial Dislocation

Retropharyngeal Reduction Plate for Treatment of Irreducible Atlantoaxial Dislocation: A Cadaveric Test and Finite Element Analysis

Retropharyngeal Reduction Plate for Atlantoaxial Dislocation: A Cadaveric Test and Morphometric Trajectory Analysis

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