Objective To explore the surgical feasibil ity and cl inical outcome of transpedicle screw fixation in treatment of atlantoaxial instabil ity and dislocation. Methods From January 2007 to June 2009, 16 patients with atlantoaxial instabil ity and dislocation were treated with transpedicle screw fixation. There were 13 males and 3 females, with a mean age of 42 years (range, 24-61 years). The transpedicle screw fixation was employed in 5 patients with old odontoid fracture (4 of Anderson type II and 1 of type III), in 4 patients with fresh odontoid fracture, in 4 patients with traumatic disruption of transverse atlantal l igament, and in 3 patients with congenital odontoid disconnection for atlantoaxial instabil ity. All patients had symptoms of cervical pain and l imition of cervical motion, 10 patients compl icated by dyscinesia and hypoesthesia of extremities. The Japanese Orthopaedic Association (JOA) score before operation was from 5 to 13, with an average of 8.5. The image examination showed atlantoaxial instabil ity or dislocation in all patients. Granulated autogenous il ium (20-30 g) was placed onto the surface of the posterior arches of both atlas and axis in some patients with old fracture of odontoid process or disruption of transverse atlantal l igament. Results The mean operative time and bleeding amount were 1.6 hours (1.2-2.5 hours) and 100 mL (50-200 mL), respectively. All the incision healed by first intension. All patients were followed up for 3-18 months, with an average of 11.5 months. The JOA score 3 months after operation was from 12 to 17, with an average of 14.2. All screws were successfully placed in atlas and axis. No postoperative compl ications such as vertebral artery injury, dural rupture, exacerbation of neurological symptoms, wound infection, and broken srews were observed in 16 cases. Postoperative radiograph and CT showed that only one screw penetrated into vertebral canal, but there was no neurological symptoms. Bony fusion was observed after 6 to 18 months of operation, and atlantoaxial rotational function in all patients restored satisfactorily, but axial rotation was partially lost. Conclusion Transpedicle screw fixation in upper cervical spine for treatment of atlantoaxial instabil ity and dislocation is safe and rel iable
From January, 1983 through December, 1993, 20 different types of operations were carried out to treat a total of 54 cases from trauma or deformities around the occipitocervical region, in which 4 patients died. The causes of the deaths were analyzed, and the main factors responsible for the mortality were improper selection of the wires for internal fixation, inadequate decompression from operation, incorrect operative technique and errors in the selection of anesthesia.
ObjectiveTo evaluate the effectiveness of the posterior atlantoaxial lateral mass screw fixation and suboccipital decompression in the treatment of Arnold-Chiari malformation associated with atlantoaxial joint dislocation. MethodsBetween September 2012 and November 2015, 17 cases of Arnold-Chiari malformation associated with atlantoaxial dislocation were treated by the posterior atlantoaxial lateral mass screw fixation and suboccipital decompression and expansion to repair the dura mater and bone graft fusion. There were 10 males and 7 females, aged 35-65 years (mean, 51.4 years). The disease duration was 14 months to 15 years with an average of 7.4 years. According to Arnold-Chiari malformation classification, 13 cases were rated as type I, 3 cases as type II, and 1 case as type III-IV. Cervical nerve root stimulation and compression symptoms were observed in 12 cases, occipital foramen syndrome in 11 cases, cerebellar compression symptoms in 6 cases, and syringomyelia in 10 cases. ResultsPrimary healing of incision was obtained in the other patients except 1 patient who had postoperative cerebrospinal fluid leakage after removal of drainage tube at 3 days after operation, which was cured after 7 days. All patients were followed up 6 months to 2 years, with an average of 18.4 months. The neurological dysfunction was improved in different degrees after operation. The Japanese Orthopedic Association (JOA) score was significantly increased to 16.12±1.11 at 6 months from preoperative 11.76±2.01 (t=13.596, P=0.000); compression of spinal cord and medulla was improved. X-ray examination showed bone graft fusion at 6 months after operation. In 10 patients with spinal cord cavity, MRI showed empty disappearance in 3 cases, empty cavity lessening in 6 cases, and no obvious change in 1 case at 6 months. ConclusionAtlantoaxial lateral mass screw fixation and suboccipital decompression and expansion to repair the dura mater can obtain good effectiveness in the treatment of Arnold Chiari malformation associated with atlantoaxial transarticular dislocation.
Objective To discuss the effectiveness of atlantoaxial joint release through anterior retrophayngeal approach and staged posterior reduction fixation and fusion for irreducible atlantoaxial dislocation (IAAD). Methods Fifteen patients with IAAD (9 males, 6 females), aged 14-53 years (mean, 31.4 years) were included in the study. The disease duration was 3 months to 17 years (mean, 5.7 years). IAAD was attributed to trauma in 13 cases, and 2 cases were caused by congenital odontoid disconnection. Preoperative imaging examination showed atlantoaxial dislocation and could not be reset automatically in functional position. The preoperative visual analogue scale (VAS) score was 3-7 (mean, 4.1), and the preoperative Japanese Orthopaedic Association (JOA) score was 10-17 (mean, 13.8). All patients received atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion. Results Anatomical reduction was achieved in all 15 patients, and the alignment of atlantoaxial joints was restored. After operation, the neck pain and neurological symptom were partially or fully improved in all patients, without deterioration of neurological function. One patient developed pharyngeal discomfort and cough after one-stage operation, 4 patients developed pharyngeal discomfort and foreign body sensation after operation, and 2 patients developed pin-path lipstick swelling during skull traction. All patients were cured by symptomatic treatment. No pulmonary infection, pressure ulcers, venous thrombosis, and incision infection was found during the treatment. All 15 patients were followed up 24-36 months, with an average of 28.6 months. Bony fusion was achieved in all patients, and the fusion time was 3-5 months, with an average of 3.6 months. At last follow-up, the VAS score was 0-2 (mean, 0.5) and the JOA score was 13-17 (mean, 15.9). There was no dislocation, recurrence, or other abnormal sign in the cervical X-ray films and three-dimensional CT. Conclusion Anatomical reduction can be achieved by atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion for treating IAAD. It is an optional procedure for IAAD.
Objective To investigate the effectiveness of computer-assisted and robot-assisted atlantoaxial pedicle screw implantation for the treatment of reversible atlantoaxial dislocation (AAD). MethodsThe clinical data of 42 patients with reversible AAD admitted between January 2020 and June 2023 and met the selection criteria were retrospectively analyzed, of whom 23 patients were treated with computer-assisted surgery (computer group) and 19 patients were treated with Mazor X spinal robot-assisted surgery (robot group). There was no significant difference in gender, age, T value of bone mineral density, body mass index, etiology, and preoperative Japanese Orthopaedic Association (JOA) score, Neck Dysfunction Index (NDI) between the two groups (P>0.05). The operation time, screw implantation time, intraoperative blood loss, hand and wrist radiation exposure, and complications were recorded and compared between the two groups. Gertzbein classification was used to evaluate the accuracy of screw implantation. JOA score and NDI were used to evaluate the function before operation, at 3 days after operation, and at last follow-up. At last follow-up, the status of screws and bone fusion were observed by neck three-dimensional CT. Results The operation time and hand and wrist radiation exposure of the computer group were significantly longer than those of the robot group (P<0.05), and there was no significant difference in the screw implantation time and intraoperative blood loss between the two groups (P>0.05). All patients were followed up 11-24 months, with an average of 19.6 months. There was no significant difference in the follow-up time between the two groups (P>0.05). There was no significant difference in the accuracy of screw implantation between the two groups (P>0.05). Except for 1 case of incision infection in the computer group, which improved after antibiotic treatment, there was no complication such as nerve and vertebral artery injury, screw loosening, or breakage in the two groups. The JOA score and NDI significantly improved in both groups at 3 days after operation and at last follow-up (P<0.05) compared to those before operation, but there was no significant difference between the two groups (P>0.05). At last follow-up, 21 patients (91.3%) in the computer group and 18 patients (94.7%) in the robot group achieved satisfactory atlantoaxial fusion, and there was no significant difference in the fusion rate between the two groups (P>0.05). ConclusionComputer-assisted or robot-assisted atlantoaxial pedicle screw implantation is safe and effective, and robotic navigation shortens operation time and reduces radiation exposure.