The use of O-arm-based intra-operative 3D scans for navigation can make cervical pedicle screw placement reliable. High accuracy and better intra-operative control can increase surgeon's confidence in using cervical pedicle instrumentation on more regular basis. These slides can be retrieved under Electronic Supplementary Material.

o drain, or not to drain, that is the question." Chronic subdural hemorrhage (SDH) or hematoma is a predominantly neurological condition usually resulting from trauma and affecting elderly individuals. 2,3,14,19 Chronic SDH is not a benign condition and is regarded as a sentinel health event because of its high morbidity and mortality rates in older people.9,18 The treatment of choice for managing chronic SDHs is surgical drainage. 12,23 Large studies have shown that older age independently contributes to increased mortality and morbidity rates after the surgical drainage of chronic SDHs. 10,22,24 As the world's elderly population increases because of adabbreviatioNs CCI = Charlson Comorbidity Index; GCS = Glasgow Coma Scale; KPS = Karnofsky Performance Scale; LOS = length of stay; SDH = subdural hemorrhage. submitted September 5, 2014. accepted December 18, 2014. iNclude wheN citiNg Published online July 10, 2015; DOI: 10.3171/2014.12.JNS142053. disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. obJective Chronic subdural hemorrhage (SDH) or hematoma is a condition that affects elderly individuals. With advances in medical care, the number of nonagenarians and centenarians will increase. However, surgical treatments in this age group are associated with high rates of morbidity and mortality. Because no data are available on the rates of survival among elderly patients with chronic SDHs who undergo surgical drainage or receive only conservative care, the goal of this study was to determine survival rates in patients 90 years of age or older with symptomatic chronic SDHs. methods The authors conducted a retrospective analysis of patient data that were collected at 3 hospitals over a 13-year period (from January 2001 to June 2013). The data from patients 90 years or older with symptomatic chronic SDHs and who were offered surgical treatment were included in the analysis. Patients who underwent surgical treatment were included in the surgical group and patients who declined an operation were included in the conservative care group. The patients' Charlson Comorbidity Index score, Karnofsky Performance Scale score, dates of death, presenting symptoms, Glasgow Coma Scale score, length of stay in the hospital, discharge location, side of the SDH, and neurological improvements at 30-day and 6-month follow-ups were recorded. Data were statistically analyzed with Fisher exact test, Kaplan-Meier curves, and logistic regression. results In total, 101 patients met the inclusion criteria of this study; 70 of these patients underwent surgical drainage, and 31 received conservative care. Patients in the surgical group had statistically significantly (p < 0.001) higher survival at both the 30-day and 6-month follow-ups, with 92.9% and 81.4% of the patients in this group surviving for at least 30 days and 6 months, respectively, versus 58.1% and 41.9%, respectively, in the conservative care group. Moreover, the mean overall length o...