Surgical procedures of thoracic ossification of the ligamentum flavum / 中华骨科杂志

ABSTRACT

Objective To investigate different surgical procedures for treatment of thoracic ossification of ligamentum flavum.Methods From January 1994 to June 2008,56 cases of thoracic ossification of ligamentum flavum underwent different surgical procedures.There were 40 males and 16 females,aged from 43 to 76 years(average 58.1 years).The courses of disease were 3 months to 5 years,average 13.4 months.CT and MRI examinations were used to observe ossification involving levels,distributions,ossification nest shapes,spinal canal stenosis and spinal cord compression and so on.All patients were treated with en bloc or dissolved laminectomy combining with posterolateral fusion.Japanese Orthopaedic Association(JOA)score was used to evaluate postoperative outcomes.Results The patients were followed up for 18 to 70 months,with an average of 25 months.The mean JOA score increased from 6.25±2.47 preoperatively to 7.53±3.20 at the final follow-up.According to CT scans,the ossifications were divided into lateral type in 6 cases,diffuse type in 17 and thickened nodular type in 33 cases.Patients of lateral type was treated with en bloc laminectomy,and the excellent and good rate was 83.3%.In the patients of diffuse type,11 were treated with en bloc laminectomy and 6 with dissolved laminectomy,and the excellent and good rate was and 81.8% and 83.3% respectively.For patients of thickened nodular type,4 were treated with en bloc laminectomy and 29 with dissolved laminectomy,the excellent and good rate was 50% and 82.8% respectively,and 2 cases presented spinal cord injury aggravation.Conclusion En bloc laminectomy combining with lateral fusion is ideal surgical procedure for lateral type and diffuse type,dissolved laminectomy combining with laeral fusion is suitable for thickened nodular type.