Clinical Effect of Staged Combined Posterior-anterior Approach on Severe Ossification of Ligamen-tum Flavum Accompanied with Posterior Longitudinal Ligament

Abstract：Objective To retrospective analyze the clinical outcome of staged combined posterior-anterior approach for os-sification of ligamentum flavum(OLF)accompanied with posterior longitudinal ligament(OPLL)complicated with cervical spon-dylotic myelopathy. Methods 18 patients with OLF accompanied with OPLL complicated with cervical spondylotic myelopathy who undernent posterior laminoplasty,anterior decompression,bone graft and internal fixation between June 2009 and June 2011 were reviewed retrospectively. Ventral compression of ossifications still presented on radiograph in 6 to 9 months after sur-gery in all cases,anterior corpectomy and dissection of OPLL as well as bone graft was then conducted. JOA,RR and cervical lordosis was used to evaluate the pre-and post-operation score and follow-up outcome. Results 1 cases presented C5 nerve root paralysis after posterior approach,3 cases were complicated with CSF leakage which resolved by conservative treatment. The mean follow-up time was 26. 3 months. The preoperative mean scores of JOA was 7. 2 ± 1. 3,cervical lordosis was(5. 7 ± 4. 1)°and JOA was(12. 6 ± 3. 8)for posterior approach with the mean improvement ratio of(51. 6 ± 19. 3)% ,cervical lordosis was( 9 . 3 ± 3 . 8 )° . The mean JOA scores after anterior decompression was 1 4 . 8 ± 1 . 6 with the mean improvement ratio of (72. 7 ± 13. 4)% compared with preoperation,cervical lordosis was(15. 5 ± 3. 2)°. Conclusion Patient with OLF accompa-nied with OPLL complicated with cervical spondylotic myelopathy undergoing posterior decompression have good clinical out-come after anterior approach operation if still presenting ventral compression. Staged combined posterior-anterior approach is a better method for patient with OLF accompanied with OPLL complicated with cervical spondylotic myelopathy.