1551. Does the Actual Lordosis Gain Following Use of Interbody Grafts in Fusion Operations Match The Expected Gain Based on the Lordosis of Graft Itself?

Authors: Yahya Othman; Virginie Lafage, PhD; Renaud Lafage, MS; Jonathan Elysee, BS; Avani Vaishnav, MBBS; Steven McAnany, MD; Todd Albert, MD; Sravisht Iyer, MD; Catherine Himo Gang; Sheeraz Qureshi, MD, MBA (New York, NY)

Introduction:

Degenerative disease of the lumbar spine is a major cause of morbidity and chronic pain in the aging population. Surgical correction is often required for relief of symptoms. Reduce motion across the painful vertebral segment as well as restoring sagittal alignment are associated with improved clinical outcomes. This study aims to assess the effectiveness of different graft types by measuring the gain in segmental lordosis at the level of fusion

Methods:

This is a retrospective study that looked at all lumbar interbody fusion procedures where a graft was used, from June 2017 to June 2018. Inclusion criteria included patients with degenerative disease of the lumbar spine that have undergone fusion surgery with the use of an interbody graft. The study assessed lateral radiographs taken preoperatively and on first visit post-operatively. The radiographs were measured for lumbar lordosis and segmental lordotic angle using the cobb method. Patient charts were reviewed to collect demographic information, as well as graft(s) model used. The lordosis of the graft was compared to the change in lumbar lordosis between pre-op and post-op measurements.

Results:

80 patients were included in this study. The date of post-operative radiologic assessment ranged from 2 to 6 weeks post operatively.  The majority of patients undergoing surgery had an improvement in sagittal alignment, with mean change in lumbar lordosis of 2˚ and mean change in segmental lordosis of 4˚. There was no significant correlation between the graft lordosis and segmental lordosis (R² = 0.0374).

Conclusion:

Graft lordosis does not predict post-operative segmental and lumbar lordosis changes. This is likely due to the presence of other contributing factors, such as surgical technique, level of fusion, as well as the severity of degenerative disease.