Efficacy of topping-off procedure for the lumbar degenerative disease: a radiographic study

English Keywords:Topping-off surgery  Degenerative lumbar stenosis  Adjacent segment degeneration  Radiographic

English Abstract:

  【Abstract】 Objectives: To evaluate the imaging changes and efficacy of Topping-off procedure for lumbar degenerative disease. Methods: From August 2008 to December 2012, 35 cases of consecutive double segmental degenerative lumbar spine stenosis(the upper segment showed mild or moderate degeneration) were treated surgically. There were 23 males and 12 females with an average age of 62.2±18.9 years(range, 30-79 years). All patients received posterior lumbar interbody fusion(PLIF) and Coflex inter-spinous dynamic stabilization at the upper adjacent level. 14 patients underwent L4/5 Coflex+L5/S1 PLIF and 21 patients underwent L3/4 Coflex+L4/5 PLIF. Retrospective analysis was conducted to evaluate the efficacy of Topping-off procedure for the prevention of adjacent segment degeneration(ASD), which included the following indexes: (1)the disc space height, range of motion, vertebra translation, inter-space angle and kyphosis angle both at the Coflex level and upper adjacent level through standing anteroposterior(AP) position, lateral and extension-flexion X-ray; (2)change of Pfirrmann disc degeneration grade at Coflex level and upper adjacent level through MRI examination. Results: All patients underwent surgery safely and no major complications occurred. The average surgery time was 112±21min. The average blood loss was 403±111ml. No spinal dura matter rupture, nerve damage or any other complication was noted. The average follow-up was 24.8±12.8 months(11-65 months). There was no significant difference in disc height at the Coflex segment or upper adjacent segment between pre-operation and final follow-up, as well as the lumbar kyphosis(P>0.05). Segmental lordosis at the Coflex level increased significantly(t=-1.8, P＜0.05). There were no significant differences in the ROM and the sagittal translation between pre-operation and final follow-up, both at the Coflex level and upper adjacent level(P>0.05). For the 24 patients followed up for more than 24 months, MRI showed no significant change of Pfirrmann disc degeneration grade between pre-operation and final follow-up both at Coflex level and upper adjacent level(P＞0.05). Conclusions: Topping-off procedure can maintain the stability as well as the adjacent unfused segment. Topping-off surgery decreases the rate of upper adjacent segment degeneration.