Abstract:

BACKGROUND: Most of lumbar degenerative diseases, such as lumbar instability and lumbar spondylolisthesis, need lumbar spinal fusion for the spine stability, but the choice of internal fixation approaches is an argument.
OBJECTIVE: To investigate the biomechanical difference of unilateral and bilateral minimally invasive transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative diseases.
METHODS: Minimally invasive TLIF with different internal fixations were performed on L4-5 segments from six fresh frozen human lumbar cadaveric specimens. Then, the specimens were divided into two groups according to different internal fixation methods: bilateral pedicle screw group and unilateral pedicle screw group. Range of motion (ROM) for the lumbar function unit was measured on the biomechanical machine and compared between the two groups.
RESULTS AND CONCLUSION: Compared with the compact lumbar function unit, the ROM of the two fixation groups were significantly lower (P < 0.05). The ROM value of the bilateral pedicle screw group was significantly lower than that of the unilateral pedicle screw group in all working states (P < 0.05). Biomechanical experiments show that unilateral TLIF provides favorable biomechanical effect and stiffness, which offers the dependable stability of the lumbar vertebrae. However, compared with the bilateral pedicle screw fixation, there are still gaps in the unilateral pedicle screw fixation.