Efficacy of posterior pedicle screw reduction and internal fixation of atlantoaxial fractures: comparison between O-arm navigation assisted and free-hand techniques / 中华创伤杂志

ABSTRACT

Objective:To investigate the effect of O-arm navigation assisted posterior pedicle screw reduction and internal fixation of atlantoaxial fractures.Methods:A retrospective case-control study was conducted to analyze 37 patients with atlantoaxial fractures admitted to Third Hospital of Hebei Medical University from January 2016 to June 2018, including 22 males and 15 females, aged from 29 to 68 years [(50.9±9.8)years]. The posterior pedicle screw reduction and internal fixation was performed under O-arm navigation system (navigation group, n=24), and using free-hand technique (free-hand group, n=13). The operation time and blood loss were compared between the two groups. The Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) were used to evaluate the clinical efficacy before operation, 7 days operation and at the last follow-up. The complications were detected. A total of 86 screws were placed in navigation group (Neo grade 0: 83 screws, grade 1: 2 screws, grade 2: 1 screw ), and 44 screws were inserted in free-hand group (Neo grade 0: 36 screws, grade 1: 5 screws, grade 2: 2 screws, grade 3: 1 screw)( P<0.05). Classification of screw positions proposed by Neo et al was used to evaluate the position relationship between the screw and the bone cortex and the incidence of screw penetration. Results:All patients were followed up 24-38 months [(27.7±4.0)months]. The operation time in navigation group was (189.8±35.4)minutes, significantly shorter than (221.5±48.6)minutes in free-hand group ( P<0.05). The bleeding volume in navigation group was 300.0 (250.0, 537.5)ml , significantly less than 500.0 (425.0, 625.0)ml in free-hand group ( P<0.05). Both groups showed significantly enhanced JOA and decreased NDI after operation and at last follow-up, compared with those before operation ( P<0.05). However, there was no significant difference in JOA and NDI between the two groups ( P>0.05). No severe complications such as neurovascular injury occurred during operation. The incidence of cortical penetration was 3% (3/86) in navigation group and 18% (8/44) in free-hand group ( P<0.05). Conclusions:In the process of posterior atlantoaxial pedicle screw placement, the application of O-arm navigation can significantly reduce the operation time and amount of bleeding, and enhance the accuracy of pedicle screw implantation.