Experimental methods
head and neck fixation, fibrous hyperplasia, incisors, atlantoaxial joint dislocation, infection, vertebra in supine position, respiratory tract infection, nasal stenosis, hyperextension
RESPIRATORY TRACT INFECTION, INFECTION, ADHESION, -20
In the traditional group, the posterior arch 18-20 mm outside the midpoint of the posterior atlantoaxial tubercle is selected as the approach point of the atlas pedicle. The approach point is the intersection of the central vertical line of the lateral mass at the lower edge of the posterior atlantoaxial arch and the upper 2 mm waterline. Keep the vertical entry direction of the nail on the horizontal plane, and ensure that the upward cutting angle of the nail on the sagittal plane is 6 °. The axial pedicle screw insertion point is located at the middle point of the upper quadrant in the back of the lower axial joint. The direction of nail insertion is 10–15 ° internal angle and 20–30 ° upper angle.The auxiliary group is treated with nasal intubation oral release decompression reduction and posterior fusion fixation assisted with the new head and neck fixation traction device: (1) Preoperative preparation. The patient is gargling with compound chlorhexidine 3 times a day, 5 min/ time, 1 week before surgery. Check the patient’s oral health and hygiene, including infection lesions, upper and lower incisors stability, dentures, etc. Check the patient’s nasal stenosis, if the above conditions, use tracheotomy. Broad-spectrum antibiotics is given intravenously 30 min before operation, and no respiratory tract infection is confirmed by examination. (2) Surgical plan. General anesthesia through nasal intubation, traction of cervical vertebra in supine position, new head and neck fixed traction device used for 2 cm amphibians to maintain traction status, gradually increasing from 3 to 15 kg below body weight. C-arm X-ray machine confirmed that it was an irreversible atlantoaxial joint dislocation fluoroscopy technology. Regularly disinfect, lay towels and install mouth plugs, pour weak iodophor water into the mouth and soak it for 5 min. Apply light drops. After repeated rinsing with physiological salt iodine, place a red urine tube into the mouth, pull the suture bundle of the tongue back along the edge, so that the posterior pharyngeal wall is fully exposed. The atlantoaxial lateral mass joint is closely adhered. The weight of hyperextension traction was increased to 12 kg in case of 1/5 − 1/3 fibrous hyperplasia and hyperosteogeny under the anterior arch of atlantoaxial vertebrae. After the adhesion joint was opened, the anterior and inferior motion of the axial odontoid process was observed by c-arm x-ray fluoroscopy. Figure 
New head and neck fixation traction device