Knee fractures can occur in young or older patients. These fractures usually occur from a fall in older patients or high-speed injuries such as motor vehicle or motorcycle accidents in younger patients. Knee fractures may involve the lower end of the thigh bone (femur), upper end of the shin bone (tibia), the kneecap (patella), or any combination of the three. X-rays show the breaks, their location and pattern. If the fracture(s) extends into the knee joint, a CT scan may be necessary to learn the true nature and extent of the fracture(s). An MRI may also be necessary to verify whether any ligaments, tendons, or cartilage structures have also been damaged. A physical examination is important to check for injuries to other structures, such as muscles, nerves, ligaments, and/or tendons.