General Session: MIS-2
Presented by: B. Walker - View Audio/Video Presentation (Members Only)
B. Walker(2),S. Miller(1), T. Callanan(2), C. Abjornson(2), R. Huang(2), F. Cammisa(2)
(1) Warren Alpert Medical School of Brown University, Providence, RI, United States
(2) Hospital for Special Surgery, New York, NY, United States
Introduction: With an aging population, spinal fusions are being performed in greater frequency to treat the degenerative changes and provide pain relief. Pedicle screw instrumentation is the most commonly used open procedure. Recently, minimally invasive approaches such as interlaminar fusion procedures have gained interest and have been shown to produce similar fusion rates and outcomes to traditional open procedures. When utilizing this type of fusion procedure, it is imperative the device is fixed to adjacent spinous processes lying between the lamina and providing support to the strongest aspect of the posterior column to avoid fractures and promote fusion. The purpose of this study is to confirm the ability of interlaminar fusion (IF) to provide similar fusion rates to pedicle screw constructs and similar outcomes.
Methods: This study is a retrospective, consecutive series of 116 patients who were treated between 2008 and 2014 at a single institution undergoing a single-level extreme lumbar lateral interbody fusion (XLIFTM, Nuvasive, San Diego, CA) with posterior stabilization. Forty-four patients received interlaminar fusion (CoFlex-F, Paradigm Spine, New York, NY) and the other 72 patients underwent pedicle screw instrumentation, either unilateral or bilateral. Preoperative radiographic images were compared to those taken at follow-up (mean: 9.7 months) to assess and compare fusion quality. The evaluated measures included changes in disc height and foraminal height as observed on standing films, as well as changes in motion at the level of intervention as determined by comparing differences in cobb angles on flexion/extension images. EBL, LOS, operative time, the need for an additional operation, and date of last prescription for narcotics were also analyzed.
Results: Both treatment options increased foraminal height( p< 0.01) as well as disc height ( p< 0.01) while yielding decreased motion at the instrumented level ( p< 0.01) compared to pre-operative values. When treatment groups were compared, the increases in foraminal height and the decreases in motion at the instrumented level were similar between the two interventions (p=0.59 and p=0.68, respectively). Further, patients with pedicle screws had a greater increase in disc height than those with IF (p< 0.01). IF patients had lower EBL (p< 0.01), LOS (p< 0.05), re-operation rate (p< 0.05), and time on narcotics (p< 0.01) while experiencing similar operative time (p=0.51) compared to pedicle screw instrumentation.
Conclusions: These results indicate that IF serves as a successful posterior stabilization device in the augmentation of one-level lateral lumbar interbody fusion. Fusion quality and rate were confirmed to be similar between patients. However, the lower morbities associated with IF may lead to better recovery and quality of life.