Geologic Constraints on the Formation and Evolution of Saturn's Mid-Sized Moons.

Saturn's mid-sized icy moons have complex relationships with Saturn's interior, the rings, and with each other, which can be expressed in their shapes, interiors, and geology. Observations of their physical states can, thus, provide important constraints on the ages and formation mechanism(s) of the moons, which in turn informs our understanding of the formation and evolution of Saturn and its rings. Here, we describe the cratering records of the mid-sized moons and the value and limitations of their use for constraining the histories of the moons.

Post-kyphoplasty myelopathy, an unusual presentation of post-operative anterior spinal cord infarct: A case report.

Highlights: To discuss a rare complication of prone positioning during kyphoplasty.To compare two rare causes of anterior spinal artery infarct secondary to prone positioning: Surfer Myelopathy and post-kyphoplasty myelopathy.

Background: Kyphoplasty is a common, minimally invasive procedure performed to restore vertebral body structure and relieve pain in insufficiency fractures that are refractory to conservative treatments.