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BACKGROUND: The use of ultrasound guidance during knee arthrocentesis has proven to increase operator confidence and accuracy, particularly in novice healthcare providers. Realistic and practical means of teaching this procedure to medical trainees are needed. This study is intended to assess the feasibility and efficacy of using formalin-embalmed human cadavers in the instruction of ultrasound-guided knee arthrocentesis to medical trainees. METHODS: Twenty participants received a 30-minute didactic orientation detailing the principles of ultrasound-guided knee arthrocentesis, followed by a training practicum performed on human cadavers. The practicum included a 25-minute training period, followed by a 15-minute assessment period. Participants were objectively assessed on their ability to independently aspirate synovial fluid from the suprapatellar bursa using ultrasound guidance. Digital pretraining and posttraining questionnaires were administered to evaluate each participant's confidence in their ability to independently locate the site of optimal needle placement and successfully aspirate synovial fluid with the guidance of ultrasound imaging. RESULTS: An analysis via the Wilcoxon rank sum testing revealed that participant self-confidence increased significantly after training across all assessment items (p < 0.0001). Fifteen participants (75%) successfully aspirated 1 mL of synovial fluid on their first attempt, whereas 3 participants (15%) were successful on their second attempt. Two participants (10%) failed to perform a successful aspiration within the 15-minute time limit. The average time required to aspirate 1 mL of synovial fluid was 41 seconds. CONCLUSIONS: Ultrasound images of the formalin-embalmed suprapatellar bursa are of sufficient quality to use in the instruction of arthrocentesis to medical trainees. Brief instruction using formalin-embalmed cadaver models significantly increases trainee confidence and prepares first-year medical students to successfully and independently perform ultrasound-guided knee arthrocentesis.
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OBJECTIVES: To determine if five commonly used prognostic indices (PIs) - recursive partitioning analysis (RPA), Score Index for Radiosurgery (SIR), Basic Score for Brain Metastases (BSBM), graded prognostic assessment (GPA), and the diagnosis-specific GPA - are valid following delay between diagnosis and treatment of brain metastases. METHODS: In a single-institutional cohort, records of patients who underwent stereotactic radiosurgery (SRS) more than 30 days from diagnosis of brain metastases were collected, and five PI scores were calculated for each patient. For each PI, three score-based groupings were made to examine survival differences by means of adjusted log-rank analysis and area under the curve (AUC). RESULTS: Of 121 patients with sufficient PI information, 72 underwent SRS more than 30 days after diagnosis. Median age and Karnofsky performance status were 60 years and 80, respectively. Forty-three (60%) patients had lung primaries. Prior to SRS, 38 (52.8%) and 12 (16.7%) patients underwent whole brain radiation therapy (WBRT) and surgery, respectively. Two (2.8%) patients underwent both WBRT and surgery prior to SRS. A median of two lesions were treated per SRS course. Median survival of the cohort was 9.0 months. Using adjusted log-rank analysis for pairwise comparison, BSBM and GPA showed significance between two out of the three prognostic groups, while the other scores showed either one or no significant differences on comparison. AUC demonstrated good applicability for BSBM, RPA, and GPA, although SIR was statistically less prognostic than the other PIs. CONCLUSION: The PIs analyzed in this study were applicable in the setting of delayed SRS. Although these data are hypothesis generating, they serve to encourage further analyses to validate a PI that is most optimal for these patients.
