Survival analysis on subchondral bone length for total knee replacement.

OBJECTIVE: Use subchondral bone length (SBL), a new MRI-derived measure that reflects the extent of cartilage loss and bone flattening, to predict the risk of progression to total knee replacement (TKR). METHODS: We employed baseline MRI data from the Osteoarthritis Initiative (OAI), focusing on 760 men and 1214 women with bone marrow lesions (BMLs) and joint space narrowing (JSN) scores, to predict the progression to TKR. To minimize bias from analyzing both knees of a participant, only the knee with a higher Kellgren-Lawrence (KL) grade was considered, given its greater potential need for TKR. We utilized the Kaplan-Meier survival curves and Cox proportional hazards models, incorporating raw and normalized values of SBL, JSN, and BML as predictors. The study included subgroup analyses for different demographics and clinical characteristics, using models for raw and normalized SBL (merged, femoral, tibial), BML (merged, femoral, tibial), and JSN (medial and lateral compartments). Model performance was evaluated using the time-dependent area under the curve (AUC), Brier score, and Concordance index to gauge accuracy, calibration, and discriminatory power. Knee joint and region-level analyses were conducted to determine the effectiveness of SBL, JSN, and BML in predicting TKR risk. RESULTS: The SBL model, incorporating data from both the femur and tibia, demonstrated a predictive capacity for TKR that closely matched the performance of the BML score and the JSN grade. The Concordance index of the SBL model was 0.764, closely mirroring the BML's 0.759 and slightly below JSN's 0.788. The Brier score for the SBL model stood at 0.069, showing comparability with BML's 0.073 and a minor difference from JSN's 0.067. Regarding the AUC, the SBL model achieved 0.803, nearly identical to BML's 0.802 and slightly lower than JSN's 0.827. CONCLUSION: SBL's capacity to predict the risk of progression to TKR highlights its potential as an effective imaging biomarker for knee osteoarthritis.

Subchondral Bone Length in Knee Osteoarthritis: A Deep Learning-Derived Imaging Measure and Its Association With Radiographic and Clinical Outcomes.

OBJECTIVE: To develop a bone shape measure that reflects the extent of cartilage loss and bone flattening in knee osteoarthritis (OA) and test it against estimates of disease severity. METHODS: A fast region-based convolutional neural network was trained to crop the knee joints in sagittal dual-echo steady-state magnetic resonance imaging sequences obtained from the Osteoarthritis Initiative (OAI). Publicly available annotations of the cartilage and menisci were used as references to annotate the tibia and the femur in 61 knees. Another deep neural network (U-Net) was developed to learn these annotations. Model predictions were compared to radiologist-driven annotations on an independent test set (27 knees). The U-Net was applied to automatically extract the knee joint structures on the larger OAI data set (n = 9,434 knees). We defined subchondral bone length (SBL), a novel shape measure characterizing the extent of overlying cartilage and bone flattening, and examined its relationship with radiographic joint space narrowing (JSN), concurrent pain and disability (according to the Western Ontario and McMaster Universities Osteoarthritis Index), as well as subsequent partial or total knee replacement. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for each outcome were estimated using relative changes in SBL from the OAI data set stratified into quartiles. RESULTS: The mean SBL values for knees with JSN were consistently different from knees without JSN. Greater changes of SBL from baseline were associated with greater pain and disability. For knees with medial or lateral JSN, the ORs for future knee replacement between the lowest and highest quartiles corresponding to SBL changes were 5.68 (95% CI 3.90-8.27) and 7.19 (95% CI 3.71-13.95), respectively. CONCLUSION: SBL quantified OA status based on JSN severity and shows promise as an imaging marker in predicting clinical and structural OA outcomes.

Divergence in the epidemiological estimates of traumatic brain injury in the United States: comparison of two national databases.

OBJECTIVE: Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in the US, but the true incidence of TBI is unknown. METHODS: The National Trauma Data Bank National Sample Program (NTDB NSP) was queried for 2007 and 2013, and population-based weighted estimates of TBI-related emergency department (ED) visits, hospitalizations, and deaths were calculated. These data were compared to the 2017 Centers for Disease Control and Prevention (CDC) report on TBI, which used the Healthcare Cost and Utilization Project's National ("Nationwide" before 2012) Inpatient Sample and National Emergency Department Sample. RESULTS: In the NTDB NSP the incidence of TBI-related ED visits was 59/100,000 in 2007 and 62/100,000 in 2013. However, in the CDC report there were 534/100,000 in 2007 and 787/100,000 in 2013. The CDC estimate for ED visits was 805% higher in 2007 and 1169% higher in 2013. In the NTDB NSP, the incidence of TBI-related deaths was 5/100,000 in 2007 and 4/100,000 in 2013. In the CDC report, the incidence was 18/100,000 in both years. The CDC estimate for deaths was 260% higher in 2007 and 325% higher in 2013. CONCLUSIONS: The databases disagreed widely in their weighted estimates of TBI incidence: CDC estimates were consistently higher than NTDB NSP estimates, by an average of 448%. Although such a discrepancy may be intuitive, this is the first study to quantify the magnitude of disagreement between these databases. Given that research, funding, and policy decisions are made based on these estimates, there is a need for a more accurate estimate of the true national incidence of TBI.

Primary intraosseous meningioma of the calvarium: A systematic review.

BACKGROUND: Primary intraosseous meningiomas (PIM) of calvarial origin are a small subset of meningiomas that arise from and occur within the calvarial bone. Its definition is often confused with other forms of non-dural based intracranial meningiomas, which has made previously published retrospective reviews heterogenous, non-specific and sometimes inaccurate. We present a systematic review of calvarial PIM. METHODS: Using a systematic search protocol that included databases such as PubMed, Web of Science and Embase, we extracted all human studies on PIM published from inception to December 2017. This systematic review includes case reports and retrospective reviews that specifically described PIM. RESULTS: On review of 166 articles identified with the systematic search protocol, 69 articles were analyzed. These comprised of 64 case reports, 1 case series and 4 retrospective reviews. 111 patients with PIM of calvarial origin were analyzed, 58 % of which were females and 42 % males. The mean patient age was 51 years and the frontal bone was the most common tumor location, occurring in 26.1 % of the cases. Surgical resection was the predominant modality of treatment in 97.2 % of the cases, and gross total resection was achieved in 84 % of cases that reported extent of resection. There were no recurrences for grade I meningiomas. However, all grade III meningiomas recurred and 33.3 % of grade II meningiomas showed recurrence with a mean postoperative follow-up interval of 20 months. Statistical analysis using Fisher's exact test showed the recurrence rate to be strongly associated with WHO tumor grade (p-value <0.001). CONCLUSION: There is statistically significant increased recurrence rate for calvarial PIM of higher grades, and we recommend close follow-up in those cases. Surgical resection remains the overwhelming treatment of choice for calvarial PIM, and it has a high gross total resection rate and low risk of complications and mortality.

Accuracy and Safety of External Ventricular Drain Placement by Physician Assistants and Nurse Practitioners in Aneurysmal Acute Subarachnoid Hemorrhage.

BACKGROUND: In the current dynamic health environment, increasing number of procedures are being completed by advanced practitioners (nurse practitioners and physician assistants). This is the first study to assess the clinical outcomes and safety of external ventricular drain (EVD) placements by specially trained advanced practitioners. OBJECTIVE: Compare the safety and outcomes of EVD placement by advanced practitioners in patients with subarachnoid hemorrhage (SAH). METHODS: A cohort comparison study was performed from an aneurysmal SAH database selecting patients treated with EVD from a single major academic institution in the USA between June 2007 and June 2017. Safety, accuracy, and complications of EVD placement were compared between advanced practitioners and neurosurgical physicians (attending neurosurgeon and subspecialty clinical fellow). Statistical analysis was performed using the Mann-Whitney test for continuous variables and χ2 test for categorical variables, with p values set at < 0.05 for significance. RESULTS: We identified 203 patients for this cohort with 238 EVD placements; eighty-seven (36.6%) placements were performed by advanced practitioners and 151 (63.4%) by neurosurgeons. Most of the ventriculostomies were placed in the emergency room (n = 114; 47.9%). Additional procedures performed concurrently with the EVD placements were significantly higher among the physicians' group (21.8 vs. 4.6%; p < 0.001). Bedside placement and usage of Ghajar guide were significantly higher among advanced practitioner's (58.3 vs. 98.9 and 9.9 vs. 64.4%, respectively, with a p < 0.001 for both). There were, however, no significant differences in terms of the number of attempts for insertion, intraprocedural complications, tract hemorrhages, accuracy, infection rates, catheter dislodgments, and need for repositioning/replacement of EVD. CONCLUSION: After appropriate training, EVD placement can be safely performed by advanced practitioners with an adequate accuracy of placement.

Validation of a Predictive Scoring System for Ventriculoperitoneal Shunt Insertion After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Hydrocephalus is a frequently encountered complication in the context of aneurysmal subarachnoid hemorrhage (aSAH). Here, we performed an external validation of the recently proposed postsubarachnoid shunt scoring (PS3) system, which aims to stratify patients presenting with aSAH based on their relative risk of requiring ventriculoperitoneal (VP) shunt insertion. METHODS: A retrospective review of all patients presenting with aSAH to our institution between July 2007 and December 2016, who underwent computed tomography imaging at the time of hospital admission, was performed. RESULTS: A total of 242 patients (66.1% women) with aSAH were included in the analysis with a mean age of 55.6 years. Sixty-four (26.4%) patients had a Hunt and Hess grade of 4 or 5 on admission. An external ventricular drain (EVD) was placed in 130 (53.7%) patients during the hospital admission. EVD placement was found to correlate with an increased rate of VP shunt placement (P < 0.001), and a trend toward an association between a high Hunt and Hess grade and VP shunt placement was observed (P = 0.05). The area under the receiver operating characteristic curve for the PS3 system was found to be 0.845. The system reliably predicted shunt-dependent chronic hydrocephalus in our patient cohort (odds ratio, 3.36; 95% confidence interval, 2.31-4.89; P < 0.001). CONCLUSIONS: Data from this study validated the previously proposed PS3 system, which was found to more accurately predict shunt-dependent chronic hydrocephalus in patients with aSAH compared with other such systems in the neurosurgical literature, such as the chronic hydrocephalus ensuing from SAH score, Barrow Neurological Institute, and shunt dependency in aSAH systems.