Clinical outcomes of skull traction and posterior occipitocervical fusion for craniovertebral anomalies combined with atlantoaxial dislocation

English Keywords:Alantoaxial dislocation  Craniovertebral anomalies  Skull traction  Occipitocervical fusion

English Abstract:

  【Abstract】 Objectives: To investigate the clinical outcomes of skull traction and posterior occipitocervical fusion for craniovertebral anomalies combined with atlantoaxial dislocation. Methods: From January 2004 to June 2011, 28 patients(18 males and 10 females) with a mean age of 31.1±14.2 years(range, 13-56 years) suffering from craniovertebral anomalies combined with atlantoaxial dislocation were reviewed. 16 patients had basilar invagination (8 os odontoidem, 6 pedicle malformation of C1-C2, 2 with both anormalities). All patients had different degree of spinal cord compression in MRI, and the preoperative JOA score was 5-9(mean, 7.2±1.4). Preoperative skull traction was performed with a mean weight of 5.2±0.7kg(range, 4-7kg) and a mean traction time of 10.1±2.1d(range, 7-14d). Preoperative X-ray showed no complete reduction in 22 patients and complete reduction in 6 patients. Posterior occipitocervical fusion surgery was then taken, and during the operation, C2 pedicle screws were implanted based on the C2 morphology(bilateral placement in 20 cases and unilateral placement in 6 cases, while no screw placement in 2 cases), and lateral mass screws were placed in other segments(2-3 segments below). Results: All patients underwent the skull traction and occipitocervical fusion successfully without any neurological deficit or vascular injury. The average operation time was 3.5 hours(range, 3-5 hours) with an average blood loss of 250ml(range, 180-400ml). No severe complications were noted. JOA score of the first day after operation was 10.6±1.5(range, 8-13), which showed significant improvement compared with preoperative ones（P<0.05）. X-ray and MRI after operation showed complete reduction in 21 patients and partial reduction in 7 cases, all patients reached decompression of spinal cords completely. The follow-up was 6-48 months, with an average time of 20.3±9.7 months, and all cases had solid bony fusion with an average of 4.3±0.9 months(range, 3-6 months). At final follow-up, the JOA score was 11-16(mean, 14.6±1.7), which improved significantly than preoperation and 1 day after operation（P<0.05）. During the follow-up, no instrument failure was noted. Conclusions: The skull traction and posterior occipitocervical fusion is effective, reliable and safe for craniovertebral anomalies combined with atlantoaxial dislocation.