Unilateral versus bilateral percutaneous pedicle screw fixation in oblique lumbar interbody fusion.

November 18, 2019

OBJECTIVE:

To compare the clinical and radiological outcomes of unilateral pedicle screws (UPS) and bilateral pedicle screws (BPS) fixations after single-level oblique lateral interbody fusion (OLIF) procedures.

METHODS:

This retrospective study included 74 patients receiving a single-level OLIF at L3-4 or L4-5 (June 2014-June 2017). These patients were divided into BPS (n=36) and UPS group (n=38). Perioperative outcomes included operating time, blood loss, medical expenses, and complication rates. Radiological outcomes included fusion rates and cage subsidence rates. Clinical outcomes included disability measured by the Oswestry Disability Index (ODI) and pain measured by the Visual Analog Scale (VAS).

RESULTS:

The operating time was significantly shorter in UPS group (76.2±4.4 min) than in the BPS group (127.0±5.6 min, p<0.001). There was a significant between-group difference in medical expenses ($11044.8±470.7 in UPS and $15018.4±547.1 in BPS, p<0.001). Blood loss and hospital stay did not differ between groups. The ODI and VAS scores significantly reduced in both groups at different time points post-operation compared to pre-operation. The UPS group had lower ODI and VAS scores than the BPS group at 7-day post-operation, but no between-group difference was found after 1-month follow-up. Fusion rate in UPS and BPS group was 86.8% and 91.7%, respectively (p>0.05). Cage subsidence rates did not differ between groups.

CONCLUSIONS:

OLIF with UPS fixation is an effective and reliable option for single-level lumbar diseases. It resulted in less blood loss, required less operative time, and had comparable effects on radiological and clinical outcomes to that of the BPS fixation.