Early clinical observation of dynamic fixed pedicle screw in Topping-off procedure for lumbar degenerative diseases

English Keywords:Adjacent segment degeneration  Dynamic pedicle screw fixation  Lumbar degenerative disease  Topping-off procedure

English Abstract:

  【Abstract】 Objectives: To evaluate the early clinical efficacy of dynamic fixed pedicle screw in the treatment of lumbar degenerative disease with Topping-off procedure. Methods: From January 2018 to December 2019, 43 patients with lumbar degenerative diseases who needed lumbar fusion surgery and whose adjacent segments had degeneration underwent Topping-off procedure by dynamic pedicle screw fixation. There were 25 males and 15 females with an average age of 61±6 years(range, 52-76 years); 32 cases underwent double segment operation and 11 cases underwent three segment operation; 8 cases were L2/3 dynamic fixation, 19 cases were L3/4 dynamic fixation, 16 cases were L4/5 dynamic fixation; 39 cases were head end dynamic fixation and 4 cases were tail end dynamic fixation. Retrospective analysis was conducted to evaluate the efficacy of lumbar degenerative disease with Topping-off procedure for the prevention of adjacent segment degeneration, which included the following indexes: Improved Oswestry disability index(ODI) and visual analogue score(VAS) of lumbar/leg pain before and after operation; Intervertebral disc improved Pfirrmann classification of dynamic fixed segment and adjacent segment; Intervertebral disc space height and range of motion of dynamic fixed segment and adjacent segment. Results: All the patients completed the operation successfully and were followed up for 12 months, and no nerve injury or complications related to implants occurred; The average operation time was 107±16 minutes(90-150 minutes), the average intraoperative blood loss was 280±72ml(200-450ml), the average hospital stay was 9±2 days(7-12 days); The ODI and VAS of lumbar/leg pain at 3 months and 1 year after operation were significantly better than those before operation(P<0.05); There was no significant difference in Pfirrmann grading between preoperative and postoperative 1 year with dynamic fixation of segments and their adjacent segments(P>0.05), but when the dynamic fixation of segment Pfirrmann grade was lower than or equal to grade V, there was significant difference between preoperative and postoperative 1 year(P<0.05); There was no significant difference in ROM and DSH of dynamic fixation segment and its adjacent segments before operation, 3 months after operation and 1 year after operation(P>0.05). Conclusions: Dynamic fixation pedicle screw in lumbar degenerative disease with Topping-off procedure has a good early clinical effect, can provide a certain degree of motion for adjacent segments of lumbar fusion, effectively maintain the height of intervertebral space and intervertebral disc status, and provide powerful conditions for reducing or delaying the occurrence and development of mid and long-term ASD.