Long-term efficacy of self-designed posterior atlas polyaxial screw-plate in the treatment of unstable atlas fracture / 中华创伤杂志

ABSTRACT

Objective:To investigate the long-term efficacy of self-designed posterior atlas polyaxial screw-plate in the treatment of unstable atlas fracture.Methods:A retrospective case series study was conducted to analyze the clinical data of 20 patients with unstable atlas fracture who were admitted to Affiliated Honghui Hospital of Xi′an Jiaotong University from January 2011 to April 2013, including 14 males and 6 females, aged 23-60 years [(42.7±8.6)years]. All the patients were treated with internal fixation using self-designed posterior atlas polyaxial screw-plate. The operation time and intraoperative bleeding volume were recorded. The fracture reduction was evaluated by CT scan at 3 days after surgery. The bone healing was observed by X-ray (anterior-posterior and lateral views of the cervical spine) and CT scan at 9 months after surgery. The delayed spinal cord injuries were evaluated by Frankel grade at 1 and 2 years after surgery and at the last follow-up. The Visual Analogue Scale (VAS) before surgery, at 3 months, 1 year, 2 years after surgery and at the last follow-up were compared. The axial rotation, flexion and extension range of the cervical spine at 3 months, 1 year, 2 years after surgery and at the last follow-up were compared. Intraoperative and postoperative complications were observed.Results:All the patients were followed up for 121-148 months [(135.0±6.8)months]. The operation duration was 68-122 minutes [(86.0±14.1)minutes], with the intraoperative blood loss of 90-400 ml [(120.0±67.9)ml]. The CT scan of the cervical spine at 3 days after surgery showed all satisfactory fracture reduction. Satisfactory bone reunion was observed at 9 months after surgery. All patients were scaled as Frankel grade E at 1 year, 2 years and at the last follow-up after surgery, with no delayed spinal cord injuries observed. The VAS scores of the cervical spine at 3 months, 1 year, 2 years after surgery and at the last follow-up were 2.0(1.3, 3.0)points, 1.0(1.0, 1.8)points, 1.0(0.3, 1.0)points and 1.0(0.3, 1.0)points, which were significantly lower than that before surgery [7.0(6.0, 7.8)points] ( P<0.05), with significantly lower scores at 1-, 2-year after surgeny and at the last follow-up than at 3 months after surgery ( P<0.05). There were no significant differences among the other time points ( P>0.05). The axial rotation ranges of the cervical spine were (103.0±8.3)°, (128.3± 11.4)° and (129.8±13.6)° at 1 year, 2 years after surgery and at the last follow-up respectively, which were significantly higher than that at 3 months after surgery [(85.3±7.0)°] ( P<0.05); It was further improved at 2 years after surgery and at the last follow-up compared with that at 1 year after surgery ( P<0.05), with no significant difference at the last follow-up compared with that at 2 years after surgery ( P>0.05). The flexion and extension range of the cervical spine at 1 year, 2 years after surgery and at the last follow-up were (65.5±4.8)°, (78.3±6.5)° and (79.3±6.9)° respectively, which were significantly higher than that at 3 months after surgery [(54.3±4.4)°] ( P<0.05); It was further improved at 2 years after surgery and at the last follow-up compared with that at 1 year after surgery ( P<0.05), with no significant difference between the last follow-up and 2 years after surgery ( P>0.05). No intraoperative injuries such as arteriovenous injury were observed. No incision infection or dehiscence occurred after surgery, with no complications caused by long-term bed rest such as lung or urinary tract infection, pressure sore formation or deep vein thrombosis occurred. No loosening or breakage of the screw and atlas plate was observed at the long-term follow-up. One patient had mild cervical pain, snap during rotation, and limited range of motion at the last follow-up. Conclusion:Self-designed posterior atlas polyaxial screw-plate has merits including small surgical wounds, satisfactory reduction, solid fixation, obvious pain relief, effective preservation of the previous cervical motion, few complications, and satisfactory long-term efficacy in the treatment of unstable atlas fracture.