Effect of Posterior Tibial Slope on Knee Kinematics After Bicruciate-Retaining Total Knee Arthroplasty.

Background: Following total knee arthroplasty (TKA), normal knee kinematics are rarely replicated. Retention of both cruciate ligaments (bicruciate retaining TKA) has helped this. Postoperative posterior tibial slope (PPTS) may further affect ligament tension and kinematics. The objective of this study is to determine how changes between the preoperative posterior tibial slope (PTS) and PPTS affect knee kinematics. Methods: Twenty bicruciate retaining TKAs were performed using standard instrumentation. Fluoroscopic kinematic data were obtained during gait and a single knee bend. Differences (Δ) between radiographic measurements of preoperative and PPTS were correlated with in-vivo knee kinematics. Patients were separated into 2 groups based on their Δ values. Group I consisted of Δ values less than 0.7, indicating either a similar PPTS compared to preoperative PTS or a slightly flatter PPTS. Group II consisted of Δ values above 0.7, indicating a steepened PPTS. Results: Preoperative PTS values ranged from -0.5° to 11.2°, with an average of 5.0° ± 3.4°. PPTS values ranged from 3.0° to 12.1°, with an average of 7.1° ± 3.1°. Weight-bearing range of motion (WBROM) measured from 94° to 139°, and femorotibial axial rotation ranged from -2.9° to 17.3°. A t-test revealed average values for WBROM in Group IT (Δ < 0.7) to be significantly greater than those for Group IIT (Δ > 0.7) (P = .01). Conclusions: These findings indicate that either a PPTS approximating the preoperative PTS or a slightly flattened PPTS in comparison (Δ < 0.7) is associated with WBROM greater than 130°. Values for axial rotation and anterior sliding were not significantly associated with changes to the PTS.

Systematic Review of Research, Mentorship, and Career Resources for Medical Students Pursuing Neurosurgical Training.

BACKGROUND: Medical students are important team members and future healthcare providers in neurosurgery or other medical fields. We performed a systematic review evaluating studies assessing medical student guidance, mentorship, and career development in neurosurgery. The study aimed to identify the best practices and acknowledge gaps requiring improvement. METHODS: A systematic review of 586 research studies evaluating important aspects of medical student career development in neurosurgery was performed. The studies were analyzed for evidence supporting specific strategies to foster career development. RESULTS: A total of 45 studies were identified and categorized into 8 categories: 1) medical student interest groups; 2) student fellowships and institutional programs; 3) research and observership funding; 4) medical student research and scholarship; 5) student-led interest groups; 6) student mentorship; 7) educational resources; and 8) diversity, equity, and inclusion for medical students. Studies supported the significant positive effects of career resources for medical students, which often resulted in higher publication quantities, increased interest in the field, and greater ease of matriculation into a neurosurgical residency. One central gap included limited formal opportunities at many institutions, including medical schools without neurosurgery programs. Additional gaps were an absent structure for many forms of mentorship and delayed engagement of medical students in neurosurgical training, which significantly affects career interests. The currently available resources for these aspects of career development are listed. CONCLUSIONS: These studies highlight the current endeavors to encourage medical student careers. However, ample gaps and missed opportunities were also identified. Further work at both institutional and national levels is needed to improve the current environment.

Are There Racial and Ethnic Health Disparities Among Outcomes After Anterior Cranial Fossa Surgery? A Propensity Score-Matched American College of Surgeons National Surgical Quality Improvement Program Study.

BACKGROUND: Race-based health care outcomes remain to be described in anterior cranial fossa (ACF) surgery. OBJECTIVE: To determine whether race predicts worse outcomes after ACF surgery. METHODS: A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program data for 2005 to 2020. Current Procedural Terminology and International Classification of Diseases-9 codes were used to identify ACF tumor cases. Propensity score matching was performed to compare White and minority patients to assess the robustness of unmatched findings. A subanalysis of pituitary adenoma (PA) resections was also performed. RESULTS: In an unmatched analysis of 1370 patients who underwent ACF surgery (67.9% White, 17.4% Black, 6.6% Asian/Pacific Islander, and 6.3% Hispanic), minority groups had higher rates of comorbidities. Unmatched multivariate analysis found Hispanic patients bore a 1.86 odds ratio (OR) of minor complications, Black and Asian and Pacific Islander patients bore 1.49 and 1.71 ORs, respectively, for extended length of stay, and Black patients bore a 3.78 OR for urinary tract infection (UTI). Matched analysis found that minority patients had higher UTI rates ( P = .02) and a 4.11 OR of UTI. In PA cases specifically, minority groups had higher comorbidities and length of stay in addition to extended length of stay odds (1.84 OR). CONCLUSION: Although most ACF surgery outcomes were unaffected by race, minority groups had more minor postoperative complications than White patients, particularly UTI. Similar disparities were observed among PA cases. Higher rates of comorbidities may also have led to longer hospital stays. Further study is needed to understand what actions might be necessary to address any race-associated health disparities in ACF surgery.

Application of Radiomics to the Differential Diagnosis of Temporal Bone Skull Base Lesions: A Pilot Study.

BACKGROUND: Temporal bone skull base pathologies represent a complex differential because they can be radiographically obscure and difficult to diagnose without biopsy. Radiomics involves the use of mathematical quantification of imaging data beyond simple intensity, size, and location to inform diagnosis and prognosis. We examined the feasibility of using radiomic parameters to help predict temporal bone tumor type. METHODS: A total of 117 radiomic parameters were analyzed from 5 magnetic resonance imaging sequences (T1 without contrast, T1 with contrast, T2, fluid-attenuated inversion recovery, apparent diffusion coefficient [ADC]) for each tumor. Statistical analysis was used to delineate known primary, metastatic/secondary, and lymphoma lesions using radiomics. RESULTS: The mean tumor volumes for the 14 primary, 12 secondary, and 8 lymphoma lesions were 2.98 ± 2.11, 3.28 ± 2.31, and 12.16 ± 7.1 cm3, respectively (P = 0.2). No significant differences in mean intensity values for any sequence helped distinguish tumors (P > 0.05), but 6 radiomic parameters were significantly correlated with diagnostic accuracy. Discriminant analysis using a stepwise algorithm generated a model where radiomic parameters for T1 cluster prominence, ADC dependence nonuniformity, T1 with contrast zone percentage, and ADC informational measure of correlation 2 achieved the best predictive model (P = 0.0001). These significant characteristics were often indirect measures of tumor heterogeneity on different magnetic resonance imaging sequences. CONCLUSIONS: These data suggest that quantitative measures of tumor heterogeneity can be discriminatory of pathology and might be integrated into clinical workflow. Although this pilot study requires further validation, these data support the exploration of radiomics in temporal bone radiographic diagnostics.

Rehabilitation After Neurotrauma: A Commentary.

Rehabilitation following neurotrauma is an important component of recovery. The best outcomes involve multidisciplinary management. This involves medical therapies, functional therapies, and physical therapies. Speech therapy, physical therapy, and occupational therapy are crucial components. Emerging evidence has implicated the need for vision therapies and a focus on mental health. A seamless integration from inpatient to outpatient is validated. This can be at outpatient facilities or home care. The importance is a key point person for the patient.

Combined Inhibition of Fyn and c-Src Protects Hippocampal Neurons and Improves Spatial Memory via ROCK after Traumatic Brain Injury.

Our previous studies demonstrated that traumatic brain injury (TBI) and ventricular administration of thrombin caused hippocampal neuron loss and cognitive dysfunction via activation of Src family kinases (SFKs). Based on SFK localization in brain, we hypothesized SFK subtypes Fyn and c-Src, as well as SFK downstream molecule Rho-associated protein kinase (ROCK), contribute to cell death and cognitive dysfunction after TBI. We administered nanoparticle wrapped small interfering RNA (siRNA)-Fyn and siRNA-c-Src, or ROCK inhibitor Y-27632 to adult rats subjected to moderate lateral fluid percussion (LFP)-induced TBI. Spatial memory function was assessed from 12 to 16 days, and NeuN stained hippocampal neurons were assessed 16 days after TBI. The combination of siRNA-Fyn and siRNA-c-Src, but neither alone, prevented hippocampal neuron loss and spatial memory deficits after TBI. The ROCK inhibitor Y-27632 also prevented hippocampal neuronal loss and spatial memory deficits after TBI. The data suggest that the combined actions of three kinases (Fyn, c-Src, ROCK) mediate hippocampal neuronal cell death and spatial memory deficits produced by LFP-TBI, and that inhibiting this pathway prevents the TBI-induced cell death and memory deficits.