Surgery for degenerative cervical spine disease in Finland, 1999-2015

Background The incidence of surgery for degenerative cervical spine disease (DCSD) has risen by almost 150% in the USA in the last three decades and stabilized at slightly over 70 operations/100,000 people. There has been significant regional variation in the operation incidences. We aim to assess the diagnosis-based, age-adjusted trends in the operation incidences and the regional variation in Finland between 1999 and 2015. Methods Data from the Finnish Hospital Discharge Register (FHDR), the Cause of Death Register, and the registers of the Social Insurance Institution were combined to analyze all the primary operations for DCSD or rheumatoid atlanto-axial subluxation (rAAS). Combinations of the operative and the diagnosis codes were used to classify the patients into five diagnostic groups. Results A total of 19,701 primary operations were included. The age-adjusted operation incidence rose from 21.0 to 36.5/100,000 people between 1999 and 2013 and plateaued thereafter. The incidence of surgery for radiculopathy increased from 13.1 to 23.3 operations/100,000 people, and the incidence of surgery for DCM increased from 5.8 to 7.0 operations/100,000 people. The rise was especially pronounced in surgery for foraminal stenosis, which increased from 5.3 to 12.4 operations/100,000 people. Of the five diagnostic groups, only operations for rAAS declined. Operations increased especially in the 40- to 65-year-old age group. The overall operation incidences varied from 18.3 to 43.1 operations/100,000 people between the university hospitals. Conclusions The age-adjusted incidence of surgery for DCSD has risen in Finland by 76%, but the rise has plateaued. Surgery for radiculopathy, especially for foraminal stenosis, increased more steeply than surgery for degenerative medullopathy, with vast regional differences in the operation incidences.