Preoperative traction followed by posterior occipitocervical reduction and fusion for basilar invagination combined with reducible atlantoaxial dislocation

English Keywords:Basilar invagination  Atlantoaxial dislocation  Skull traction  Reduction  Occipitocervical fusion

English Abstract:

  【Abstract】 Objectives: To evaluate the efficacy of preoperative skull traction and posterior occipitocervical reduction and fusion for basilar invagination combined with reducible atlantoaxial dislocation. Methods: Twelve patients(9 males and 3 females) with basilar invagination combined with reducible atlantoaxial dislocation were treated surgically from March 2004 to June 2012. The mean age was 37.5±18.7 years old(ranging from 8 to 63 years old). The clinical manifestation showed cervicobrachialgia in 3 patients, dizziness in 1 patient, and the other patients all had obviously neurological deficits. The mean JOA score before the operation was 8.3±2.1(5-12) points. The mean preoperative cervicomedullary angle was 108.9°±8.1°(108°-121°). All the patients underwent skull traction for 7 to 28 days(average, 14.7±8.1d) before surgery. Once the odontoid process got good reduction, the skull traction continued for 3 to 5 days, followed by posterior instrumentation and occipitocervical fusion with screw- rod system. After operation, all patients wore hard collar fixation for 3 months. Results: All patients showed good clinical result due to the reduction of odontoid process. No complication happened during and after the surgery. 11 patients were followed up successfully. The average follow-up time was 43.0±19.6 months(ranging from 8-98 months). No internal instrument failure was noted. All patients had good fusion with an average fusion time of 4.3 months(ranging from 3-6 months). The neurological deficit recovered well. The mean JOA score at last follow-up was 15.1±1.6 points(ranging from 8-17 points), which significantly increased compared with that before surgery(P<0.05).The recovering rate of neurological function was 78.2%. The mean cervicomedullary angle at the last follow-up was 133.3°±9.3°(ranging from 125°-141°), which significantly increased compared with that before surgery(P<0.05). The evaluation of operative effects at the last follow-up was: 6 patients achieved good, 4 improved, 1 better based on Epstein standards. Conclusions: Preoperative skull traction and posterior occipitocervical reduction and fusion is safe, simple and effective for basilar invagination combined with reducible atlantoaxial dislocation.