Pathological unit and the octagonal en bloc resection of thoracic ossification ligamentum flavum / 中华骨科杂志

ABSTRACT

Objective To describe the pathological unit and octagonal en bloc resection for the treatment of ossification ligamentum flavum(OLF)in thoracic spine with spondylotic myelopathy.Methods Ninety-five patients from January 2002 to January 2007 were diagnosed as thoracic OLF,61 males and 34 females with an average age of 53.9 years(range,31-78 years).There were upper thoracic spine OLF in 32 cases,middle thoracic spine OLF in 24 cases and lower thoracic spine OLF in 39 cases.Single-segment OLF was found in 53 cases,double segments OLF was found in 38 cases and three segments OLF was found in 4 cases.CT scan multiplanar co-localized reconstruction was employed to detect the structure of spine with OLF.The Japanese Orthopaedic Association(JOA)lower limb motor function score,sphincter function score and motor function improvement rate were used to evaluate the outcomes.Results CT scan was engaged to observe 141 OLF pathological unite.The OLF pathology unit was defined as all the spine structures between the extension lines of the lower margin of the OLF two adjacent pedicles.Each OLF associates with an OLF pathology unit.The mean follow up duration was 38.3 months(range,24-60 months).Among 86 patients with sensations disturbance before operation,67 totally recovered and 19 relieved after operation.Trunk restrictions in 69 cases before operation were completely recovered after operation.Postoperative JOA sphincter function score was 2.651±0.334,comparing with preoperation score(2.262±0.561),and the difference was statistically significant.Postoperative JOA motor function score was 3.694±0.429,which was significantly increased than preoperative score 1.539±0.873,and motor function recovery rate was 87.57%.There was excellent in 71 cases,good in 17 cases and fair in 5 cases.The excellent and good rate was 94.74%.Conclusion The octagonal en block resection is relative safe for treatment thoracic OLF with myelopathy.Pathological unit of OLF in thoracic spine is more accurate to summarize the pathological contents and features of the OLF and its adjacent structure.