Clinical and radiological outcomes after posterior lumbar interbody fusion by the vertebral end plate degeneration

Abstract

The vertebral end plate changes (Modic changes) are suggested as a one of the source of low back pain. And posterior lumbar interbody fusion (PLIF) is effective for the treatment of low back pain due to degenerative disc disease associated with the vertebral end plate changes. This study was designed to evaluate the efficacy of PLIF with posterior pedicle screw fixation in chronic degenerative disc disease with Modic changes.A total of 320 patients who underwent single level spinal fusion operation (PLIF with posterior pedicle screw fixation) from January 2003 and December 2007 and followed up more than 12 months were enrolled in this study. The patient’s mean age was 55.6±10.7 years old and mean follow-up was 28.52±17.1 months. Patients were classified into 4 categories (Modic 0 to 3) according to Modic changes based on pre-operative lumbar magnetic resonance images. Factors such as patient’s age, smoking habit, osteoporosis that may affect fusion rate were also analyzed. Clinical data were analyzed with 10-point visual analog scale (VAS) and Oswestry Disability Index (ODI).The overall bone fusion rate was 86.6% and 88.7% in Modic type 0, 81.2% in Modic 1, 86.0% in Modic 2 and 75.0% in Modic type 3. There were no significant differences between Modic groups (p = 0.220). Patient’s age (p = 0.242), smoking habit (p = 0.095), osteoporosis (p = 0.270), operated level (p = 0.966) and diagnosed disease (p = 0.988) also did not show significant differences. In all groups, significant post-operative clinical improvements (p = 0.000) were shown and there were significant differences between Modic types. In conclusion, PLIF with additional posterior pedicle screw fixation seems to be an effective procedure in regarding of clinical outcome and bone fusion rate.