ABSTRACT
Objective To compare the surgical effects between minimally invasive anterior ondontoid screw fixation assisted by our self-designed odontoid guider and open anterior ondontoid screw fixation in the treatment of odontoid fractures of Anderson-D'Alonzo type Ⅱ.Methods From July 2011 to July 2016,28 adults with odontoid fracture of Anderson-D'Alonzo type Ⅱ were treated at Department Ⅱ of Spinal Surgery,Hospital of 89 Army Group of Chinese PLA.Of them,15 were treated by minimally invasive anterior ondontoid screw fixation assisted by our self-designed odontoid guider (guider group) while the other 13 by open anterior ondontoid screw fixation (open group).All the patients were male,aged from 31 to 59 years (average,42.7 years).The 2 groups were compared in terms of incision length,operation time,intraoperative bleeding,intraoperative fluoroscopic frequency and hospital stay.Results There were no significant differences between the 2 groups of patients in their preoperative general data,indicating they were compatible (P ＞ 0.05).All the patients were followed up for 12 to 45 months (average,22.1 months).The internal fixation was in good place and clinical union achieved in all the 28 patients.The incision length (2.2 ± 0.1 cm),operation time (45.0 ± 3.1 min),intraoperative bleeding (29.0 ± 2.3 mL) and intraoperative fluoroscopic frequency (15.5 ± 1.9 times) for the guider group were all significantly less than those (2.9 ±0.7 cm,61.6±3.8 min,51.6±3.9 mL and 21.7±3.2 times,respectively) for the open group (P ＜0.05),but there was no significant difference between the 2 groups in hospital stay (6.5 ± 0.5 d versus 6.5 ± 0.6 d) (P ＞ 0.05).Conclusion In the treatment of odontoid fractures of Anderson-D'Alonzo type Ⅱ,compared with open anterior ondontoid screw fixation,the minimally invasive anterior ondontoid screw fixation assisted by our self-designed odontoid guider may lead to a smaller incision,shorter operation time,less blood loss and a lower fluoroscopic frequency.
ABSTRACT
Objective To explore a simple classification of the axial mastoid process and its clinical significance in improving the traditional screw insertion in the treatment of odontoid fracture with percutaneous anterior odontoid screwing. Methods The median sagittal CT images of 120 patients with cervical dis-ease were measured. They were 63 males and 57 females, aged from 31 to 59 years (average, 41.6 years). On their median sagittal CT images, line A was the connection of the lowest point of the anterior inferior boarder of the axis body to the vertex of the odontoid process and line B a parallel line to line A through the mastoid process. The distance between lines A and B was measured (the height of the axial mastoid process) and a complete statistical record was made to analyze the distribution and regularity of distances AB. The improved insertion points were indentified based on the above measurements (X25%and X75%) and clinical ex-perience. We reviewed 32 patients with odontoid fracture of Anderson&D' Alonzo typeⅡA, ⅡB or superficialⅢ. Of them 15 underwent percutaneous anterior screwing by the improved insertion points and 17 underwent percutaneous anterior screwing by the conventional insertion points. The 2 groups were compared in terms of incision length, operation time, bleeding, fluoroscopy frequency and hospital stay. Results Distance AB was 3.42 ± 0.68 mm. The distance AB <3 mm was classified as low-level mastoid process, the distance AB between 3 to 4 mm as slightly convex mastoid process, and the distance AB > 4 mm as convex mastoid process. Of the 120 patients, 32 (26.7% ) were classified as having a low-level mastoid process, 57 (47.5%) as having a slightly convex mastoid process, and 31 (25.8%) as having a convex mastoid process. Compared with the conventional insertion group, the improved insertion group had significantly shorter oper-ation time (31.32 ± 2.12 min versus 46.18 ± 3.63 min), significantly lower fluoroscopy frequency (18.20 ±1.57 times versus 21.27 ± 2.50 times) but significantly greater bleeding (43.22 ± 3.17 mL versus 31.22 ± 3.52 mL) (P <0.05). There were no significant differences between the 2 groups in incision length or hospital stay (P > 0.05). Conclusions In the treatment of odontoid fracture with percutaneous anterior odontoid screwing, the screw insertion can be improved according to our classification of the axial mastoid process. Our simple classification of the axial mastoid process may lead to more efficient operation and less radiation hazard.