ABSTRACT
Objective To assess the efficacy of internal fixation assisted with Halo-vest in the treatment of Anderson-D'Alonzo type Ⅱ and superficial type Ⅲ odontoid fractures.Methods A retrospective case series study was made on 15 patients clinically diagnosed as Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures with a fracture gap over 2 mm,displacement over 5 mm and broken end angel over 11° from January 2007 to January 2015.There were nine males and six females,aged 27-61 years [(44.5 ± 10.9)years].The patients were treated in "three phases" with the assistance of Halo-vest external fixation system and a novel guide pin aiming device.The three phases were as follows:phase Ⅰ:cervical traction reduction and halo-vest external fixation;phase Ⅱ:Halo-vest assisted internal fixation using the novel aiming device;phase Ⅲ:the Halo-vest fixation removal and cervical collar fixation.Operation duration,intraoperative bleeding,and postoperative visual analogue scale (VAS) pain score one month after the operation were recorded.The cervical lateral and open mouth X-ray or atlantoaxial CT scan with sagittal and coronal two-dimensional reconstruction were regularly reviewed,and the location of screws,reduction and fracture healing were evaluated.Results Operation duration ranged from 54 to 96 minutes [(71.3-± 11.9) min].The intraoperative blood loss was 5-60 ml [(32.6 ± 16.8) ml].There was no spinal cord or nerve root injury,cerebrospinal fluid leakage,wound infection or other complications.All patients were followed up for 12-36 months (mean,28 months).Fourteen patients were seen bony union 6 months after the surgery and one patient was seen a false joint.At the last follow-up,the patient with false joint was seen bone sclerosis,and other patients with sound bone healing.The preoperative VAS and that of one month after the operation was (7.3 ± 0.6) points and (1.6 ± 0.7) points,respectively (P ＜ 0.05).Conclusion For Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures,which have a fracture gap greater than 2 mm,displacement more than 5 mm,broken end angle above 11 degrees,the three-phase Halo-vest assisted internal fixation can provide good stability before operation and promote bone healing and pain relief after operation.