The Influence of Comorbidities on Reoperations Following Primary Surgery of Lumbar Degenerative Diseases : A Nationwide Population-Based Retrospective Cohort Study from 2009–2016. - Hyung-Ki Park; Su-Yeon Park; Poong-Hhoon Lee; Hye-Ran Park; Sukh-Que Park; Sung-Jin Cho; Jae-Chil Chang (Journal of Korean Neurosurgical Society, 2020)