Pediatric Triplane Ankle Fractures: Impact of Radiographs and Computed Tomography on Fracture Classification and Treatment Planning.

BACKGROUND: The purpose of this study was to compare the reliability of triplane fracture classification, displacement measurement, and treatment planning with the use of radiographs with and without computed tomography. METHODS: One pediatric radiologist, one musculoskeletal radiologist, and three fellowship-trained pediatric orthopaedic surgeons rated a spectrum of twenty-five triplane fractures with use of radiographs alone and then with computed tomography scans on two separate occasions (two to four weeks apart). Raters classified the fracture pattern with use of the Rapariz classification system, measured the maximum intra-articular displacement, and drew the fracture on four outlines of the distal part of the tibia: one lateral view, one anteroposterior view, one axial view above the tibial physis, and one axial view below the physis. Reliability was assessed with kappa values and intraclass correlation coefficients. RESULTS: The Rapariz triplane fracture classification had poor inter-rater reliability (a kappa of 0.17) and intra-rater reliability (a kappa of 0.31) with radiographs alone but moderate inter-rater reliability (a kappa of 0.41) and intra-rater reliability (a kappa of 0.54) with the addition of computed tomography. After reviewing computed tomography, raters changed the fracture pattern in 46% of ratings, the displacement from ≤2 mm to >2 mm in 39% of ratings, the treatment from nonoperative to operative in 27% of ratings, and either the orientation or number of screws in 41% of ratings. CONCLUSIONS: Computed tomography had a definite impact on the fracture classification, displacement, and treatment plan, supporting its use as an adjunct to radiographs for the treatment of pediatric triplane fractures.

Mouse embryonic stem cells undergo charontosis, a novel programmed cell death pathway dependent upon cathepsins, p53, and EndoG, in response to etoposide treatment.

Embryonic stem cells (ESCs) are hypersensitive to many DNA damaging agents and can rapidly undergo cell death or cell differentiation following exposure. Treatment of mouse ESCs (mESCs) with etoposide (ETO), a topoisomerase II poison, followed by a recovery period resulted in massive cell death with characteristics of a programmed cell death pathway (PCD). While cell death was both caspase- and necroptosis-independent, it was partially dependent on the activity of lysosomal proteases. A role for autophagy in the cell death process was eliminated, suggesting that ETO induces a novel PCD pathway in mESCs. Inhibition of p53 either as a transcription factor by pifithrin α or in its mitochondrial role by pifithrin µ significantly reduced ESC death levels. Finally, EndoG was newly identified as a protease participating in the DNA fragmentation observed during ETO-induced PCD. We coined the term charontosis after Charon, the ferryman of the dead in Greek mythology, to refer to the PCD signaling events induced by ETO in mESCs.