409 - Epidemiological Trends in Interspinous Process, Pedicle-based Dynamic...

#409 Epidemiological Trends in Interspinous Process, Pedicle-based Dynamic Stabilization and Facet Replacement Devices between 2007-2011

Lumbar Therapies and Outcomes

Poster Presented by: K. Singh


S.V. Nandyala (1)
A.J. Marquez-Lara (1)
S.J. Fineberg (1)
M. Pelton (1)
M. Noureldin (1)
K. Singh (1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States


Introduction: Interspinous process spacers (ISP), pedicle based dynamic stabilization devices (PBDS), and facet replacement (FR) devices were introduced as minimally invasive and motion-sparing alternatives to treat lumbar degenerative pathologies. The purpose of this study was to analyze a population-based database to characterize the national trends of these procedures in regards to the incidence, demographics, co-morbidities, costs, and mortality.

Methods: Data from the National Inpatient Sample was queried from 2007-2011. Patients undergoing an insertion of an interspinous process spacer (ISP), pedicle-based dynamic stabilization device (PBDS), or a facet replacement device (FR) in order to treat lumbar radiculopathy, degenerative disc disease, or lumbar spinal stenosis were identified. Comorbidities were calculated utilizing a modified Charlson Comorbidity Index (CCI) score. The patient demographics (gender, age, and race), hospital length of stay (LOS), costs, and mortality were also assessed in the three surgical cohorts during this period. SPSS v.20 was utilized for statistical analysis with a Pearson Correlation Co-efficient with an alpha-level of < 0.05.

Results: The national weighted estimate of dynamic stabilization cases peaked in 2008 (4,695) and steadily declined to 1,212 in 2011. The ISP and PBDS cohorts demonstrated the greatest decrease in incidence (p< 0.001; r = -0.1). In addition, the mean age at surgery in the ISP and FR cohorts demonstrated a significant downtrend (p< 0.001; r = -0.1). In all cohorts from 2007-2011, the mean CCI (1.9 - 3.9 respectively; p< 0.001; r = +0.4), LOS (1.8 - 2.2 days respectively; p< 0.001; r = +0.1), and the total hospital costs ($14,079 - $18,586 (2010) respectively; p< 0.001; r = +0.2) significantly increased. Lastly, there were no significant changes in mortality during this period (p=0.08).

Conclusion: From 2007-2011, the utilization of interspinous spacers, pedicle based dynamic stabilization systems, and facet replacement devices has declined since their peak in 2008. Patients undergoing these procedures during this period were associated with a mounting comorbidity burden and demonstrated a significant uptrend in the mean LOS and total hospital costs. None of the surgical cohorts were associated with significant changes in mortality. Further studies are warranted to characterize the decline of these procedures and the associated long-term outcomes compared to traditional lumbar decompression and fusion techniques.

Lumbar Spacers Trends