Introduction: Cervical fusion is a common surgical modality used in the treatment of cervical spondylotic myelopathy (CSM). It is unclear how national trends in the surgical management of CSM have evolved since 2002.

Methods: The National Inpatient Sample (NIS) was used to identify adult patients with CSM (International Classification of Disease, Ninth Revision, Clinical Modification [ICD-9-CM] code 721.1) who underwent cervical fusion from 2003-2013. Patients were stratified based on procedure: anterior cervical fusion (ACF) or posterior cervical fusion (PCF) (ICD-9-CM codes 81.02 and 81.03, respectively). Data points included age, gender, race, comorbidity burden, primary insurance beneficiary, hospital size, geographic location, teaching status, and the outcome measures of in-hospital mortality, length of stay (LOS), and hospital charges. Chi-square tests were performed to compare categorical variables. Independent t-tests using the Satterthwaite method were performed to compare continuous variables.

Results: We identified 62,970 patients with CSM who underwent cervical fusion from 2003-2013. The number of fusions performed per year to treat CSM increased from 3,879 to 8,181. Patients tended to be male, white, and insured privately (ACF) or by Medicare (PCF). The average age of fusion patients increased from 58.2 to 60.6 years (p<0.001). The percentage of patients with three or more comorbidities increased from 14.8% to 34.3% (p<0.001). Fusions were increasingly performed at smaller hospital centers. LOS did not change significantly from a mean of 3.7 days. In-hospital mortality decreased from 0.6% to 0.3% (p<0.01). Hospital charges increased from $49,445 to $92,040 (p<0.001). Trends for ACF and PCF were broadly similar to the all fusions cohort.

Conclusions: This study showed a dramatic increase in cervical fusions to treat CSM from 2003-2013. Despite increases in average age and number of comorbidities, smaller hospitals performed more fusions for CSM with LOS remaining constant and mortality decreasing across the study period. However, hospital charges increased dramatically.

Patient Care: This research will improve patient care because it provides updated information on the national trends in the surgical management of cervical spondylotic myelopathy to spine surgeons. In turn, the information can be used to inform and direct standards of care.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand trends in patient demographics, hospital characteristics, and outcomes following cervical fusion for the treatment of cervical spondylotic myelopathy. 2) Know the break down of trends for all cervical fusions into anterior and posterior cervical fusions in the treatment of cervical spondylotic myelopathy. 3) Discuss why there is no change in length of stay and decreasing mortality following cervical fusion for cervical spondylotic myelopathy, despite patients who are getting older and who have a greater comorbidity burden. 4) Speculate why charges are trending upward with regards to patient demographics and outcomes in the surgical management of cervical spondylotic myelopathy.

References: 1. Iyer A, Azad TD and Tharin S. Cervical Spondylotic Myelopathy. Clin Spine Surg. 2016. 2. Lebl DR and Bono CM. Update on the Diagnosis and Management of Cervical Spondylotic Myelopathy. Journal of the American Academy of Orthopaedic Surgeons. 2015; 23: 648-60. 3. Lad SP, Patil CG, Berta S, Santarelli JG, Ho C and Boakye M. National trends in spinal fusion for cervical spondylotic myelopathy. Surg Neurol. 2009; 71: 66-9; discussion 9.