Safety in Allowing Residents to Independently Perform Appendectomy: A Retrospective Review.

BACKGROUND: In an era of competency-based education and concern about graduating resident readiness for practice, early resident autonomy and the ability to safely teach junior residents is becoming increasingly important. In this study, we aimed to understand the effect of "teaching resident" (2 residents operating under the supervision of an attending physician) appendectomy cases on outcomes. STUDY DESIGN: We performed a single-center retrospective review of 928 patients who underwent appendectomy within the University of Wisconsin hospital system, from October 2014 to December 2017. We examined how 2 residents (compared with 1 resident with an attending) attempting a case affected operation time, surgical site infection (SSI) rate, conversion to open rate, postoperative CT scanning, and readmission rate, while controlling for sex, age, American Society of Anesthesiologists (ASA) class, BMI, previous lower abdominal surgery, acuity, perforation, and presence of a junior attending. RESULTS: We identified 597 1-resident cases and 331 2-resident or "teaching resident" cases. We performed multiple logistic regression to assess teaching resident cases as a predictor of postoperative outcomes. There were no significant differences in postoperative surgical site infection (superficial or organ space) odds ratio (OR) = 0.83 (95% CI, 0.47, 1.45); p = 0.51, conversion to open OR = 1.10 (95% CI, 0.46, 2.60); p = 0.84, postoperative CT scanning OR = 0.82 (95% CI, 0.48, 1.35); p = 0.42, or readmission within 30 days OR = 0.76 (95% CI, 0.40, 1.44); p = 0.40. However, teaching resident operative times were more likely to be classified as prolonged OR = 1.44 (95% CI, 1.03, 2.01); p = 0.03. CONCLUSIONS: Senior surgical trainees can safely supervise more junior trainees performing appendectomy procedures, and training programs should encourage faculty to allow residents to not only manage operative appendicitis as independently as possible, but to supervise junior residents in the intraoperative management of appendicitis.

Accuracy of model-based tracking of knee kinematics and cartilage contact measured by dynamic volumetric MRI.

The purpose of this study was to determine the accuracy of knee kinematics and cartilage contact measured by volumetric dynamic MRI. A motor-actuated phantom drove femoral and tibial bone segments through cyclic 3D motion patterns. Volumetric images were continuously acquired using a 3D radially undersampled cine spoiled gradient echo sequence (SPGR-VIPR). Image data was binned based on position measured via a MRI-compatible rotary encoder. High-resolution static images were segmented to create bone models. Model-based tracking was performed by optimally registering the bone models to the volumetric images at each frame of the SPGR-VIPR series. 3D tibiofemoral translations and orientations were reconstructed, and compared to kinematics obtained by tracking fiducial markers. Imaging was repeated on a healthy subject who performed cyclic knee flexion-extension. Cartilage contact for the subject was assessed by measuring the overlap between articular cartilage surfaces. Model-based tracking was able to track tibiofemoral angles and translations with precisions less than 0.8° and 0.5mm. These precisions resulted in an uncertainty of less than 0.5mm in cartilage contact location. Dynamic SPGR-VIPR imaging can accurately assess in vivo knee kinematics and cartilage contact during voluntary knee motion performed in a MRI scanner. This technology could facilitate the quantitative investigation of links between joint mechanics and the development of osteoarthritis.