Short-Term Comparison Between Unilateral Versus Bilateral Percutaneous Pedicle Screw Fixation in Short-Level Lateral Lumbar Interbody Fusion-A Prospective Randomized Study

Study design: Prospective randomized controlled trial.

Objectives: No prospective studies have directly compared clinical and radiographic outcomes of unilateral vs bilateral instrumented lateral lumbar interbody fusion (LLIF) for lumbar degenerative disease (LDD). We compared the short-term radiographic, clinical outcomes, and some complications of the unilateral percutaneous pedicle screw (PPS) (UPS) vs bilateral PPS (BPS) fixation in short-level spinal fusion with LLIF for LDD.

Methods: This was a prospective randomized controlled study of 33 patients who underwent UPS or BPS fixation after LLIF for LDD; 18 patients were assigned to the UPS group and 15 patients to the BPS group. Clinical outcomes, complication rates, and fusion rates were assessed.

Results: The two groups were similar in age, sex, preoperative diagnosis, and level of surgery. Blood loss, length of hospital stay, and numeric rating scale score one year after surgery did not differ between groups. The operative time was longer in the BPS than UPS group (120.2 vs 88.8 min, respectively; P = .029). Both groups showed improvement in disc height and dural sac in the immediate postoperative computed tomography and magnetic resonance imaging, which did not differ significantly between groups. The subsidence grade and fusion rate did not differ, but cage subsidence was more severe in the UPS than BPS group.

Conclusion: Unilateral and bilateral PPS fixation after LLIF yielded similar short-term clinical and radiological outcomes. However, severe cage subsidence was more common in the UPS group, which suggests that BPS fixation after LLIF may be a better choice over the long term.