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  • Comparative Study of Unilateral and Bilateral Pedicle Screw Fixation in Transforaminal Lumbar Interbody Fusion: Radiological and Clinical Analysis

    Final Number:

    Alan T. Villavicencio MD; Benjamin Jon Serxner MD, BS; Alexander Mason MD; Kara Dawn Beasley; Lee Nelson MD; Nathan Faes BA; Sigita Burneikiene MD

    Study Design:
    Clinical Trial

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2013 Annual Meeting

    Introduction: Biomechanical comparison of supplemental interspinous process fixation plate (ISFP) as an adjunct to unilateral pedicle screws (UPS) to bilateral pedicle screw (BPS) fixation was performed and significant increase in foraminal height has been previously reported, but the ability of this technique to achieve the same goals has not been studied clinically with standardized radiographic and clinical outcome measures.

    Methods: Ninety-nine and 76 patients underwent TLIF for painful degenerative disc disease with either UPS/ISFP or BPS fixation, respectively. All consecutive patients who had no previous fusion surgeries, one- or two-level TLIF procedures (L3 – S1 levels) from May 2008 to November 2010 were included in this analysis. A direct comparison of clinical outcomes radiographic and surgical parameters was made.

    Results: The increase in disc height (DH) was observed at all levels and in both groups, but there were no statistically significant differences, except at L5/S1 levels: the UPS/ISFP patient group had a significantly higher increase in DH (4.1 mm vs. 1.1 mm; P<0.0001). Foraminal height (FH) decrease was found at all levels, except at L5/S1 for both groups. There were no statically significant changes or differences in sagittal and segmental alignment measurements between the groups. Although clinical outcome scores improved significantly and satisfaction scores were quite high, there were no significant differences when clinical outcomes (VAS, SF-36, Oswestry, satisfaction) were compared between patients who underwent TLIFs using with UPS/ISFP or BPS fixation. Highly significant differences were observed for all surgical parameters: 112 vs. 268 mL estimated blood loss (p<0.0001); 138 vs. 201 min surgery time (p<0.0001); 1.3 vs. 3.2 days hospitalization time (p<0.0001) for the UPS/ISFP and BPS patient groups, respectively.

    Conclusions: This study demonstrated that it is possible for TLIF with UPS/ISFP fixation to achieve clinical and radiological outcomes comparable to TLIF with BPS fixation. The potential benefits of performing TLIF with UPS/ISFP fixation are reduced blood loss, surgery and hospitalization times.

    Patient Care: Surgical procedures that are less technically complex and invasive have reduced risk of complications, shorter hospital stays, decreased blood loss, operative time and faster recovery.

    Learning Objectives: The participants will be able to appreciate the advantages of this less invasive approach presented.


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