Short-Term Therapeutic Efficacy of the Isobar TTL Dynamic Internal Fixation System for the Treatment of Lumbar Degenerative Disc Diseases.

Background: At present, posterior interbody fusion surgery with pedicle internal fixation is the gold standard for the treatment of lumbar degenerative disc diseases. However, an increasing number of studies have shown that because fused lumbar vertebrae lose their physiological activity, the compensatory range of motion (ROM) of the adjacent levels increases. To address this issue, dynamic internal fixation systems have been developed.

Objective: Our goal was to investigate the short-term therapeutic efficacy of the Isobar TTL dynamic internal fixation system for the treatment of lumbar degenerative disc diseases and its effect on the ROM of the surgical segments.

Study Design: Retrospective Evaluation.

Setting: Tertiary hospital setting in China.

Methods: Twenty-four lumbar degenerative disc disease patients who underwent posterior lumbar decompression and single-segment Isobar TTL dynamic internal fixation at our hospital between January 2013 and July 2014 were retrospectively analyzed. The preoperative and one month, 3 month, and 12 month postoperative visual analog scale (VAS) pain scores, Japanese Orthopedic Association (JOA) scores, and Oswestry Disability Index (ODI) scores were observed and recorded to assess the clinical therapeutic effect; the lumbar ROM was measured preoperatively and at the last follow-up to evaluate the preservation of functional movement in the dynamically stabilized segment.

Results: All patients underwent the operation successfully without complications during hospitalization and were followed for 12 to 27 months, with an average of 18 months. The patients' preoperative and one month, 3 month, and 12 month postoperative VAS scores were 6.42 ± 0.72, 1.71 ± 0.86, 1.38 ± 0.65, and 1.37 ± 0.58, respectively, and their JOA scores were 9.54 ± 1.89, 21.21 ± 1.98, 22.50 ± 1.47, and 23.46 ± 1.32, respectively. The preoperative ODI score was 42.04 ± 2.63; the one month, 3 month, and 12 month postoperative ODI scores were 22.79 ± 1.61, 18.63 ± 1.61, and 15.08 ± 1.21, respectively. These results suggest that the VAS score at each postoperative time point was significantly lower than the preoperative score and that function was significantly improved postoperatively compared with preoperative function; all of the differences had statistical significance (P < 0.05). The patients' preoperative lumbar ROM and the ROM at 12 months post operation were 3.46 ± 1.02 and 2.25 ± 0.79, respectively; the difference was not statistically significant (P = 0.11).

Limitations: The follow-up time is not long enough.

Conclusions: The treatment of lumbar degenerative disc diseases with the Isobar TTL dynamic internal fixation system can effectively relieve pain, improve quality of life, and preserve the lumbar ROM of the stabilized segment with a satisfactory clinical therapeutic effect.