Clinical outcome of revision surgery for atlantoaxial dislocation

English Keywords:Atlantoaxial dislocation  Revision surgery  Transoral approach  Posterior reduction  Fixation

English Abstract:

  【Abstract】 Objectives: To investigate the key point and clinical outcome of revision anterior release and posterior reduction and fusion for the failed atlantoaxial dislocation. Methods: A total of 29 cases suffering from atlantoaxial dislocation and neurological deficit due to failed surgery between October 2001 and October 2011 underwent revision surgery, of them, 26 were followed up. There were 12 males and 14 females with the age at primary surgery averaged at 33.5 years(range, 4-56 years), and averaged at 37.2 years at the time of revision surgery, with the average interval of 44.2 months(range, 11-158 months). The result of the revision surgery included no reduction in 8 cases and recurrent dislocation after instrumentation in 18 cases. The average preoperative cervicalmedullary angle(CMA) was 101.8°. All patients presented with continuous neck pain and 19 cases suffered from neurological deficit, with the average JOA score of 8.5. All cases underwent one-stage anterior transoral atlantoaxial release and posterior reduction and decompression, atlantoaxial or occipitocervical fusion.The protocol included 12 C1-C2 fusion, 6 C0-C2 fusion, 3 C0-C3 fusion, 3 C0-C4 and 2 C1-C4 fusion. JOA(17 points) score and radiograph were used to evaluate the surgical outcome during follow-up. Results: The average surgical time was 290min(range, 210-340min) and the average blood loss of 700ml(range, 500-1100ml). No neurovascular injury or deep infection was noted. 19 cases(73.1%) got complete reduction finally, while 7 cases got incomplete reduction. The CMA increased from preoperative 101.8° to postoperative 143.0°(11 normal and 15 less than normal). All patients were followed up for an average of 45 months(range, 18-90 months). No instrument failure was noted in any case. 19 cases with neurological deficit had preoperative JOA score of 8.5 increasing to 12.6 at final follow-up. Based on Macnab criteria, there were 10 excellence, 6 good, and 3 fair. Conclusions: One-stage anterior transoral atlantoaxial release and decompression by posterior reduction and fusion is reliable, less invasive and effective for atlantoaxial dislocation.