The Posterior Surgery In The Treatment Of Atlantoaxial Dislocation For Clinic Research

Background and objectivesAtlantoaxial dislocation（AAD）is the upper cervical spine of common disease, the maincause is congenital odontoid developmental malformation and atlantoaxial ligamentunderdevelopment, also include trauma and tuberculosis, rheumatoid and pathologicalfactors. Atlantoaxial dislocation can cause serious neurological symptoms, the compressionhigh cervical spinal cord and even the medulla oblongata, If the form chronic compression,it may lead to the formation of syringomyelia; it may cause lack of feeling unwell, lack ofpower, high paraplegia, urine dysfunction, even threaten the life. Therefore, timelydiagnosis and treatment are very important. With advances in imaging technology and thedevelopment of surgical instrument is the constant updates, the deepen understanding of theAAD increasely, the surgical therapy treatment of AAD operation method is also inconstant improvement. According to the clinical symptoms and signs and the use ofimaging, nerve electrophysiology auxiliary examination, if the diagnose for AAD is clear,must take the effective operation method treatment, so as to ensure that life safety ofpatients.About the operation method treatment of AAD, traditionally used more anteriorapproach, that is, transoral odontoidectomy. This operation is the oropharyngeal approach,through cutting dens down or pulling the axis, can be directly to reduce spinal cord ventralcompression, but the operation finished in a relatively pollution environment andpreoperative preparation work long, perioperative, surgical field exposure difficulties,postoperative complications such as infection, cerebrospinal fluid leakage, and long timebefore eating shortcomings, still need to doⅠ/Ⅱ period of posterior fixation. In recentyears, pedicle screws and lateral mass screws with a rapid development of technology, lowcomplications, gradually become a hot spot of the treatment of IAAD. But research showsthat20%of the atlantoaxial dislocation of vertebral pedicle with developmental deformity, and often pedicle screws in a serious occurred after the transverse foramen or vertebralartery damage, or even though no postoperative of vertebral artery or effect the spinal canalor influence, but still have the potential danger; And the atlantoaxial lateral masstechnology, perioperative need to keep the back in this position and perspective,postoperative retraction force too big, cause atlantoaxial unsatisfied reduction.Some clinical researchs found that: axis lamina both in spinous process to the length ofthe transverse foramen, lamina height, nail into perspective, and biomechanical, canaccommodate3.5mm cross screws, and can achieve the same effect as pedicle screws, theoperation area small, safe and convenient, less complications. But clinical applicationreport only individual cases, the lack of system research. Therefore, we look back on theanterior and always by the treatment of the posterior comparison AAD, based on selectpatients lamina screws technology and pillow cervical fusion, treatment AAD achievedgood effect. The postoperative symptoms significantly reduced, and the imaging tip:odontoid reposition is good, cerebrospinal fluid circulation unobstructed, syringomyeliasignificantly reduce, vertebral artery and the spinal canal reached zero damage, no case wascomplications. Through to the treatment of patients with the effect, the recovery andfollow-up and data analysis, further proof cross lamina posterior screw open reduction andinternal fixation technology safety, effective and feasible; In addition, the surgical operation,easy to master, can quickly remove the patients with pain, should be emphasized and thefurther promotion.Materials and methodsPart1: The comparison of clinical efficacy between the anterior and posterior surgery in thetreatment of atlantoaxial dislocation. Retrospective analysis in September2004toDecember2010, and the third military medical university first affiliated hospitalneurosurgery microsurgical treatment in14cases AAD with cranial neck deformity,respectively, take two different operation by the good way of ransoral odontoidectomy (theanterior), t; directly reduced pressure reduction posterior screw-titanium rod (board) systemin fixed technology (the posterior); The anterior approach6cases, the posterior8cases,patients were followed up6~48months, through the two operation time, between JOAscores and the nerve electrophysiology detection comparison, the clinical curative effect of the anterior and posterior approach were evaluated.Part2: The clinic analysis of the posterior lamina screws internal fixation for the treatmentof atlantoaxial dislocation. Sum up in May2010to November2011, the third militarymedical university first affiliated hospital southwest hospital neurosurgery posterior laminacrossing the distraction reduction and internal fixation of microsurgery for AAD withcranial neck deformity, meet criteria for the letters and telephone and continuous completefollow-up clinical material a total of12cases，intraoperative without perspective, andresection of posterior arch of the atlas to reach decompression, indirectly, reduced to spinalcord, direct vision through the pedicle screws or lamina screws, and distract between theoccipital titanium plate and screws, occipital-cervical fusion, make the spinal cord of thedens reduction forward, and get stable. Follow-up4~20months, bone fusion good, withoutany complications, through the before and after operation anlanto-odontoid interval, CL(Chamberlain ’s line) and ML (McRae’ s line) distance above, cervicomedullary angle(CMA), JOA score and the nerve electrophysiology detection of comparison, the operationmethod of clinical analysis.ResultsPart1：1, The posterior surgery by the time (179.60±45.75) min is anterior operation time(548.30±121.40) min significantly shortened; The posterior JOA score (16.00±1.07) pointsmore anterior (13.33±2.33) points increased obviously. Surgery blood loss: the posterior(153.80±72.30) ml is anterior (330.00±200.00) ml reduce, preoperative and postoperativeneurological electrophysiology detection waveform recovery rate (71.43%) than to anterior(50%) have improved, The postoperative of posterior approach syringomyelia reduce(54.29±10.41)%than anterior one (21.62±7.67)%2，Imaging examination by a posterior approach of anterior cerebrospinal fluidcirculation well, neural function recovered well, occipital-cervical area reduced pressurefully bone for osseous fusion area, without any nerve and the blood vessel damage.Part2：1，With a significant relief, the postoperative JOA score increased (5.88±1.88) points;Imaging review: cerebrospinal fluid circulation well, posterior fixation stability. Patients were followed up, with a good recovery, pillow neck area reduced pressure fully bone forosseous fusion area, has not found screws loose, fracture, etc.2，Posterior lamina measurement: the lamina screws can achieve the length: the left28.89±2.37(mm), the right29.04±3.19(mm); Lamina thickness: left4.56±0.60(mm), theright4.76±0.87(mm); Lamina long axis and sagittal alignment Angle: the left45.43±6.38(°), the right:48.06±5.94(°). All can accommodate3.5mm screws, avoid screw vertebralartery and the spinal canal to the damage.3, The posterior cross lamina screws board (great) system open reduction and internalfixation decompression surgery before and after the treatment. The anlanto-odontoidspacing reduced the1.46±1.15(mm); odontoid axon CL reduced from3.14±1.93(mm);Dentate from ML reduced at2.95±2.5(mm); Delay reduced ridge Angle6.24±2.73(°);syringomyelia narrowed (54.29±10.41)%; the treatment effect is obvious. Directly visionsmall range of operation. peripheral nerve plexus, vein plexus especially vertebral artery nodamage.4，The indications of the new technology should further widen and standard, the organrange and injury is small in the operation, safer and less complications.Conclusions1, The posterior distract reduction and internal fixation treatment method of AAD andIAAD to anterior approach, the operation relatively easy, safe and effective.2, The axis crossing translaminar screws posterior reduction and fixation as a treatmentof AAD and IAAD, feasible and the treatment effect is obvious.