Objective To compare the safety and clinical efficacy of freehand and 3D printing navigation template assisted screw placement in patients with old odontoid fractures of type Ⅱ.Methods Total of 38 patients with old odontoid fractures of type Ⅱ were treated from November 2018 to December 2022,all of which presented as chronic neck pain.According to the dif-ferent methods of screw insertion into the pedicle,the patients were divided into a navigation template group and a freehand group.In the navigation template group,there were 17 patients including 9 males and 8 females with an average age of(51.30±13.20)years old,disease duration was(22.18±7.59)months.In the freehand group,there 21 patients including 7 males and 14 females with an average age of(49.46±11.92)years old,disease duration was(19.52±9.17)months.The intraoperative blood loss,operation time,and postoperative drainage output were recorded and compared between two groups.The accuracy of screw placement was evaluated by CT scan.Before operation and 1 year after operation,cervical pain was assessed by visual analogue scale(VAS),neurological changes were evaluated by the Japanese Orthopaedic Association(JOA)score,and the de-gree of spinal cord injury was assessed by the American Spinal Injury Association(ASIA)injury scale.Results All patients were followed up for(25.31±1.21)months.The operation time of template group(112.00±20.48)min had significantly shorter than that of the freehand group(124.29±15.24)min(P＜0.05),while there were no significant differences between two groups in terms of intraoperative blood loss,postoperative drainage,and hospital stay(P＞0.05).At 1 year after operation,in template group and freehand group,the VAS[(2.88±0.86),(2.90±0.83)]and JOA[(14.94±1.82),(14.62±2.19)]improved with pre-operative[VAS(4.71±0.92),(4.86±0.79)and JOA(12.18±2.30),(11.95±2.31)](P＜0.05),with no significant difference between two groups(P＞0.05).No significant improvement was observed in ASIA grading in either group at 1 year after opera-tion(P＞0.05),and there was no significant difference between two groups(P＞0.05).The template group had significantly better accuracy of screw placement in the pedicle of the axis than the freehand group(P＜0.05),while no significant difference was observed between two groups in the accuracy of screw placement in the pedicle of the atlas(P＞0.05).Conclusion In the treat-ment of type Ⅱ old odontoid fractures with posterior pedicle screw fixation,3D printing navigation template screw placement can significantly shorten the operation time,achieve similar clinical efficacy as free-hand screw placement,and significantly im-prove the accuracy of screw placement in the pedicle of the axis.

OBJECTIVE: To evaluate the clinical and radiological results of patients with thoracic and lumbar fracture and dislocation treated by posterior transforaminal decompression and interbody fusion. METHODS: From June 2010 to June 2017, posterior transforaminal decompression, interbody fusion combined with pedicle screw fixation were performed in 21 patients with thoracic and lumbar fracture and dislocation. Their clinical and radiological data were collected and retrospectively analyzed, including 15 males and 6 females, aged from 25 to 58 years with an average of 45 years old. According to the criterion of American Spinal Injury(ASIA), preoperative neurological function was graded A in 3 cases, B in 7 cases, C in 6 cases, D in 4 cases and E in 1 case. Operative time and intraoperative blood loss and correlative complications were recorded. And VAS score, ODI and Cobb angle were evaluated before and after surgery. The improvement of neurological function was also analyzed at the final follow-up. Intervertebral bony fusion was observed during the follow-up by CT three-dimensional reconstruction. RESULTS: The operative time was 150 to 240 min with an average of (192±47) min. The intraoperative blood loss was 380 to 750 ml with an average of(603±120) ml. Dura sac tearing and cerebral fluid leakage occurred in 3 cases and were repaired during operation; superficial wound infection occurred in 1 case, and got healing after dressing change. The postoperative follow-up duration was 24 to 45 months with an average of(37.0±9.5) months. VAS score was improved from preoperative 8.9±0.4 to immediately postoperative 4.2±1.3(<0.05). At the final follow-up, VAS score decreased further to 3.6±0.8. ODI was decreased from preoperative (95.30±3.52)% to (32.51±6.30)% at the final follow-up (<0.05). Cobb angle was corrected from preoperative (21.2±8.8)° to immediately postoperative(2.3±3.1)° (<0.05). At the final follow-up, Cobb angle was (3.2±2.5)°, showing no significant difference with immediately postoperative value. The neurological function was grade A in 3 cases, B in 3 cases, C in 5 cases, D in 6 cases and E in 4 cases at the final follow-up. All the patients got solid intervertebral bone fusion in 8 to 13 months after operation, with an average fusion time of (10.3±2.5) months. CONCLUSIONS For the patients with thoracic and lumbar fracture and dislocation mainly involving intervertebral disc and endplate plane, posterior transforaminal decompression and interbody fusion not only is less invasive, but also can effectively reconstruct spinal three column and obtain good biomechanical stability. And, it is beneficial for the good recovery of neurological function.
Adult ; Decompression, Surgical ; Female ; Humans ; Lumbar Vertebrae ; Male ; Middle Aged ; Pedicle Screws ; Retrospective Studies ; Spinal Fusion ; Treatment Outcome