The aim of this study was to review and analyze the neurosurgery body of literature to document the current knowledge of frailty within neurosurgery, standardizing terminology and how frailty is defined, including the different levels of frailty, while determining what conclusions can be drawn about frailty's impact on neurosurgical outcomes. While multiple studies on frailty in neurosurgery exist, no literature reviews have been conducted. Therefore, we performed a literature review in order to organize, tabulate, and present findings from the data to broaden the understanding of what we know from frailty and neurosurgery. We performed a PubMed search to identify studies that evaluated frailty and neurosurgery. The terms “frail,” “frailty,” “neurosurgery,” “spine surgery,” “craniotomy,” and “neurological surgery” were all used in the query. We then organized, analyzed, and summarized the comprehensive frailty and neurosurgical literature. The literature contained 25 published studies analyzing frailty in neurosurgery between December 2015 and December 2018. Five of these studies were cranial neurosurgical studies, the remaining studies focused on spinal neurosurgery. Over 100,000 surgical cases were analyzed among the 25 studies. Of these, 18 studies demonstrated that increasing frailty was associated with increased rate of complications, 10 studies showed that frailty was associated with higher mortality rates, 11 studies demonstrated an association between frailty and increased hospital length of stay, and 5 studies noted that higher frailty was associated with discharge to a higher level of care. The current body of literature repeatedly demonstrates that frailty is associated with worse outcomes across the neurosurgical subspecialties 1).
From a chronological viewpoint, medical treatment of the elderly (geriatrics) starts from the age of 65 years old. This definition per se is nowadays certainly not really an adequate definition of an elderly patient and the reason to be treated by a geriatrician. In addition to chronological age, other factors must be considered in order to define the elderly patient. Functional reserves decrease with age, which leads to increased vulnerability. Frailty as a term describes this situation and can be defined pathophysiologically by a mainly subclinical inflammatory state. Therefore, in 2007 the German Society of Geriatrics (DGG), the German Society of Gerontology and Geriatrics (DGGG), and the German Group of Geriatric Institutions (BAG) have jointly developed a definition of the geriatric patient 2).