[Posterior fusion versus posterior interbody fusion in segmental spinal fixation for aged spondylolisthesis].

Objective: Clinical and radiographic results in 30 consecutive patients undergoing posterior lumbar fixation and posterior facet joint or posterior interbody fusion for Meyerding Grade II/III spondylolisthesis were assessed: (1) to address the suitability of a dynamic stabilization; and (2) to investigate whether there are differences in terms of clinical and functional results between these two types of arthrodesis.

Methods: Fourteen patients underwent posterior interface fusion (PLF) and implantation of TSRH-3D system. Posterior lumbar interbody fusion (PLIF) and placement of the same system were performed in 16 patients. Clinical, economic, functional and radiographic data were recorded both pre- and postoperatively.

Results: The average changes in Prolo Scale of economic and functional scores were 1.25 and 1.64 respectively, in patients undergoing posterior fusion; the average measured vertebral slippage was 48.6% (range 32%-65%) preoperatively and 17.5% (range 15%-25%) postoperatively. In patients undergoing PLIF, the average changes in economic and functional score were 1.18 and 1.39 respectively, and the average preoperative vertebral slippage was 44.2% (range 30%-55%) versus 20.3% (range 18%-26%) postoperatively.

Conclusion: The use of a segmental pedicle screw fixation with TSRH-3D was able to successfully combine the goal of solid fusion with the requirements of nerve root decompression. When these two fusion techniques were compared, PLIF was superior to PLF because of an overall superior reliability and system resistance. But their clinical outcomes did not differ greatly (P > 0.05).