[Topping-off surgery versus double-segment fusion for treatment of lumbar degenerative disease with mid-long term follow-up].

Objective: To compare the mid-long term clinical effect of Topping-off surgery and lumbar fusion surgery for two-segmental lumbar degenerative disease. Methods: From March 2009 to March 2012, one hundred and twenty-six consecutive patients (Topping-off surgery and two-segment PLIF surgery) were studied in Orthopedics Department, Beijing Chao-Yang Hospital, Capital Medical University.The VAS and ODI were used to assess clinical symptoms.All patients underwent flexion/extension radiographs examinations before surgery, 1, 2 years and last follow-up postoperatively.Lumbar lordosis, sacral slop, data of Coflex segment and adjacent segment (disc height index, range of motion, foraminal height, foraminal width and Pfirrmann classification of intervertebral disc in MRI) were recorded.The paired double-tailed t test was used to analyze the differences in the results from baseline to each postoperative time point.The paired double-tailed t test was used in both groups to analyze the differences in the results from baseline to each postoperative time point.The Chi-square test was used to evaluate the differences between the incidences of adjacent segment degeneration(ASD) in the groups. Logistic regression analysis was used to analyze risk factors for developing radiographic ASD. Results: In topping-off group, 60 patients, average operation time was (134.5±10.2) min. The average blood loss was (301.5±64.6) ml.In fusion group, 68 patients, average age (58.3±4.6) years.The average follow-up time was (47.5±5.1) months.The average operation time was (158.6±19.3) min (P=0.000). The average blood loss was (413.6±131.3) ml (P=0.000). Sex, age, body mass index and intervertebral disc grading were matched between the two groups.Better improvement in VAS back pain score was noted in the topping-off group over the fusion group (P=0.030). Both groups achieved good recovery in ODI and improvement in VAS leg pain and back pain scores at last follow-up postoperatively.In the Topping-off group, FH increased from 10.5 mm at baseline to 11.8 mm at 1 year after surgery (P=0.000) and then decreased mildly in the third postoperative year, while in the fusion group, showed no significant change at all postoperative time points.In the fusion group, the disc height and FW at the same segment were no significant change after first year follow-up, while ROM was significantly decreased after surgery (P=0.000). Foraminal height, foraminal width and intervertebral disc height of adjacent segment of Coflex implant level were found decreased at the end of the postoperative follow-up, while compared with preoperative data no significant difference (P>0.05). At last follow-up, eight patients (13.3%) in the Topping-off group and eighteen patients (26.5%) in the fusion group developed ASD (P=0.033). Conclusions: Topping-off surgery compared with two-segment lumbar fusion surgery can achieve a good result in cases with pre-existing mild or moderate adjacent segment degeneration, restrict the adjacent segment's range of motion and reduce the adjacent segment degeneration. Under strict indications, Topping-off surgery is an acceptable alternative to fusion surgery for the treatment of two-segment lumbar disease.