To study project of simpl icity and util ity for screw-plate system by pedicle of atlanto-axis mani pulatively hand by X-ray film and CT to prove the one success rate of putting screws. Methods Formulate personal program was used in operation by image save transmission of X-ray film and CT during January 2002 and September 2006 in 31 patients. There were 18 males and 13 femals, aged from 23 to 61 years old with an average age of 43.5 years. Putting screw points bypedicle of atlas were measured: left (19.93 ± 1.32) mm, right (19.16 ± 1.30) mm; putting screw obl iquity angle to inside by pedicle of atlas: left (23.72 ± 2.09)°, right (23.35 ± 1.91)°; putting screw obl iquity angle to side of head by pedicle of atlas: (9.00 ± 1.20)°. Screw points by pedicle of axis: left (13.14 ± 0.82) mm right (13.85 ± 0.79) mm; putting screw obl iquity angle to inside by pedicle of axis: left (24.52 ± 1.26)°, right (20.42 ± 1.42)°; putting screw obl iquity angle to side of head by pedicle of axis: (25.00 ± 3.00)°. The domestic location toward speculum was employed in operation and putting screw points and angles were formulated by X-CT program. The pedicle screws of suitable diameter and length were of exception and screws into pedicle of atlanto-axis were put by hand. Results Pain of the greater occipital nerve occurred in 2 patients after operation and was fully recovered by treatment 1 month after operation. The lateral cortical bone of pedicle was cut by 2 screws, but the spinal cord and vertebral artery were fine. The atlas and the fracture of odontoid process of axis were completely replaced in X-ray films of all patients 1 day after operation.The position relation of lag screw and vertebral artery or spinal cord was very good in CT sheets. All cases were followed up with an average of 10.5 months during 9 months to 5 years and 4 months, and obtained atlantoaxial arthrodesis. The breakage of screw and plate was not found in all cases. According to JOA score standard, 16 cases were excellent, 12 were good, 2 were fair, 1 was poor, and the excellent and good rate was 90.32% . Conclusion The personal design and cl inical appl ication of X-ray films and CT sheets are of great significance to screw-plate system by pedicle of atlanto-axis because of simpl ification of designs and methods and better personal ity.
【Abstract】 Objective To determine the three-dimensional stabil ity of atlantoaxial reconstruction withanterior approach screw fixation through C2 vertebral body to C1 lateral mass and Gall ie’s technique (ASMG) for C1,2instabil ity. Methods Twenty-five human cadaveric specimens (C0-3 ) were divided randomly into 5 groups (n=5). Thethree-dimensional ranges of motion C1 relative to C2 were measured under the five different conditions：the intact state group (group A), type II odontoid fracture group (group B), posterior C1,2 transarticular screw fixation group (group C), ASM group (group D) and ASMG group (group E). The three-dimensional ranges of motions C1 relative to C2 by loading ± 1.5 Nm were measured under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation. The obtained data was statistically analyzed. Results In each group, the three-dimensional ranges of motion C1 relative to C2 under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation were as follows: in group A (8.10 ± 1.08), (8.49 ± 0.82), (4.79 ± 0.47), (4.93 ± 0.34), (28.20 ± 0.64), (29.30 ± 0.84)°; in group B (13.60 ± 1.25), (13.80 ± 0.77), (9.64 ± 0.53), (9.23 ± 0.41), (34.90 ± 0.93), (34.90 ± 1.30)°; in group C (1.62 ± 0.10), (1.90 ± 0.34), (1.25 ± 0.13), (1.37 ± 0.28), (0.97 ± 0.14), (1.01 ± 0.17)°; in group D (2.03 ± 0.26), (2.34 ± 0.49), (1.54 ± 0.22), (1.53 ± 0.30), (0.80 ± 0.35), (0.76 ± 0.30)°; in group E (0.35 ± 0.12), (0.56 ± 0.34), (0.44 ± 0.15), (0.55 ± 0.16), (0.43 ± 0.07), (0.29 ± 0.06)°. Under the six conditions, there were generally significant differences between group A and other four groups, and between group B and groups C, D and E (P lt; 0.001), and between group E and groups C, D in flexion/ extension and left/right lateral bending (P lt; 0.05). There was no significant difference between group E and groups C, D in left/right axial rotation (P gt; 0.05). Conclusion In vivo biomechanical studies show that ASMG operation has unique superiority in the reconstruction of the atlantoaxial stabil ity, especially in controll ing stabil ity of flexion/extension and left/right lateral bending, and thus it ensures successful fusion of the implanted bone. It is arel iable surgical choice for the treatment of the obsolete instabil ity or dislocation of C1, 2 joint.
Objective To explore the anatomic basis for theanterior approach screw fixation through the C2 vertebral body into the C1 lateral mass and toinvestigate its primary clinical application. Methods Twenty-one adult corpse specimens were anatomically measured. The minimum lateral angle α, the maximum lateral angle β, and the maximum posterior angle γ were calculated based on the data from the anatomic measurement. All the specimens were given an X-ray examination, the minimum lateral angle α, the maximum lateral angle β, and the maximum posterior angle γ were measured. The statistical analysis was made on the data obtained from the calculation in the specimens and the measurement in the X-ray films. The simulation of the approach was made onthe specimen. From October 2004 to July 2006, the simulated approach was used in 5 patients (3 males, 2 females; age, 30-55 years; illness course, 3 months-2 years) with the old atlanto-axial joint dislocation . The Frankel grading system revealed the spinal cord injury degree as follows: 1 patientwas in Grade B, 2 in Grade C, and 2 in Grade D. All the patients were treated with this surgical approach. The postoperative X-ray and CT examinations were performed. Results Angle α was 14.0±1.6°, β was 30.0±2.3°, γ was 29.0±2.9°. No significant difference existed between the angles calculated in the specimens and measured in the X-ray films (Pgt;0.05). The angles for the practical application during operation were as follows: α was 11.2±1.6°, β was 28.8±2.3°, and γ was 29.3±2.9°. The follow-up for an average of 14 months revealed that 1 patient recovered to Grade C, 1 to Grade D2, and 3 to Grade D3 in the spinal cord function according the modified Frankel grading system.Conclusion The anterior approach screw fixation through the C2 vertebral body into the C1 lateral massis feasible and safe in treatment of the old atlantoaxial joint dislocation ifthe screw insertion is exact in direction. This technique only makes the atlas temporarily stable, and so the posterior bone graft should be added into the atlantoaxial joint immediately in the one- or two-stage operation so as to achieve a long-lasting stability.
OBJECTIVE: To explore a new surgical treatment of old atlantoaxial dislocation. METHODS: 5 patients aged 12 to 45 years, who suffered from old atlantoaxial dislocation for 1 to 4.5 years, received the new surgical treatment by the transoccipitocervical posterolateral approach, and expansion of the foramen magnum, odontectomy and bony fusion of the occipitoatlantoid region were performed. Neurological examinations and CT scan were undertaken after operation. RESULTS: All 5 patients survived. Sensory function recovered almost completely and motor function was better more than 1 degree. CT scan showed the diameter of the spinal canal restored well. CONCLUSION: The transoccipitocervical posterolateral approach is an ideal and safe pathway to reach the site of old atlantoaxial dislocation and the operating field is exposed completely. Anterior-posterior decompression and occipitocervical spinal fusion can be performed simultaneously