gms | German Medical Science

Objective: Semi-rigid stabilization was introduced due to the concept of load sharing. We propose a topping-off technique leaving the most upper motion segment without anterior cage in order to reduce adjacent segment disease (ASD) by creating a smooth transition from stabilized to free motion segments. The objective of this study was to evaluate the influence of these angles on reoperations to investigate potential impacts.

Methods: We report on the initial 322 patients enrolled from 2009 to 2015. Reoperation rate subjective patients' satisfaction, and various other outcome measures were evaluated. All patients underwent pedicle screw-based semi-rigid stabilization of the lumbar spine with a polyether ether ketone (PEEK) rod system. All patients underwent computed tomography or x-ray after surgery. Mean follow-up was 4.75 ± 1.79 years after surgery.

Results: For 40.1% of patients implantation of the PEEK rod system was the first lumbar surgery while 59.9% received it as revision surgery after decompression or following ASD after dynamic or rigid stabilization. A median of 3 (range 2 to 5) motion segments were included while a median of 2 (range 1 to 4) motion segments were fused. 65.5% of patients underwent TLIF, 16.2% ALIF in the same surgery. Segments without anterior fusion represent semirigid stabilization without the topping-off technique. Combined radicular and lumbar pain was reduced from 7.88 out of 10 (visual analogue scale=VAS) before to 3.99 after maximum follow-up of 4.75 years during which 16.4% of patients underwent revision surgery due to ASD or screw loosening.

Conclusion: The PEEK rod concept including the topping of principle seems safe with at least average satisfaction at least in short-term follow up. Concerning the low rate of first tier surgeries, the presented results are superior to most other series.