2023, Vol. 27 ›› Issue (4): 594-599

Posterior single-segment pedicle screw fixation for unstable atlas fractures

Bao Kai, Song Wenhui, Liu Changwen, Liang Kaiheng, Wang Jiajia   

Abstract: BACKGROUND: In recent decades, the treatment of unstable atlantogenic fractures has been controversial, and the choice of surgical methods has evolved from C1-C2 or C0-C2 fusion to the present situation of preserving motor segments as much as possible. However, the reduction effect and postoperative complications of both oral and posterior approaches remain to be improved.
OBJECTIVE: To observe the effect of posterior single-segment pedicle screw fixation on unstable atlas fractures.
METHODS: Clinical data of 14 patients with unstable atlas fractures admitted from July 2017 to September 2020 in Second Hospital of Shanxi Medical University were retrospectively analyzed. There were 10 males and 4 females, with an average age of 51.8 years. All patients underwent posterior open reduction and internal fixation using a single-segment pedicle screw-rod system. Medical records and preoperative and postoperative radiographs were reviewed, and preoperative and postoperative CT scans were used to determine fracture types and assess fracture reduction. According to Spence's standard, the sum of displacement on both sides of the atlas in the mouth-opening X-ray film ≥6.9 mm was judged as unstable atlas fractures. At the last follow-up, cervical hyperextension and hyperflexion X-ray films were used to assess the stability of the atlantoaxial joint.
RESULTS AND CONCLUSION: (1) All 14 patients were successfully operated. The mean follow-up duration was (21.0±6.4) months. Postoperative cervical X-ray and CT examination showed that the internal fixation position was good and the reduction was good. None of the patients had neurological impairment, vertebral artery injury, wound infection or other surgery-related complications. (2) Visual analogue scale score significantly decreased from (6.5±1.3) before operation to (1.9±0.8) after operation (P < 0.05). Neck Disabilitv Index score significantly decreased from (74.4±4.5) before surgery to (12.1±4.3) at the last follow-up (P < 0.05). (3) At the last follow-up, cervical flexion and extension ranged from 70° to 88° (79.7±6.0)°. Left and right cervical flexion ranged from 76° to 85° (82.1±2.8)°. Left-right rotation ranged from 129° to 155° (143.5±8.4). Cervical range of motion was well recovered in all patients at the last follow-up. X-ray films of cervical hyperextension and flexion at the last follow-up did not show any influence of atlantoaxial joint instability. After surgery, four patients complained of neck stiffness with limited movement, which basically returned to a normal level under standardized rehabilitation and guided treatment. (4) It is concluded that posterior single-segment pedicle screw internal fixation for unstable atlas fractures has short operation time, less blood loss, fewer complications, and better reduction effect. More importantly, the patient’s neck flexion, extension and rotation functions are basically not limited. For C1 fractures, transverse ligament rupture may not be a contraindication for open reduction and internal fixation, but the long-term effects of C1-C2 instability remain to be investigated.
Key words: atlas fraction, cervical posterior, single vertebral segment, internal fixation, pedicle screw, fracture reduction