The localization in theropod scapulae as evidenced by the tendon avulsion in Sue suggests that theropods may have had a musculature more complex and functionally different from those of their descendants, the birds. The divot appears to be located at the origin of the deltoid or teres major muscles. Scars from these sorts of injuries were limited to the humerus and scapula. Among the dinosaurs studied, avulsion injuries were only noted among Tyrannosaurus and Allosaurus.
In 2001, Bruce Rothschild and other paleontologists published a study examining evidence for tendon avulsions in theropod dinosaurs. Open reduction (using surgical incision) and internal fixation is used when pins, screws, or similar hardware is needed to fix the bone fragment. ĭisplaced avulsion fractures are best managed by either open reduction and internal fixation or closed reduction and pinning. If the fracture is small, it is usually sufficient to treat with rest and support bandage, but in more severe cases, surgery may be required. Tibial tuberosity avulsions occur most often in teenagers that engage in a large amount of sporting activities, and many studies have shown a history with Osgood-Schlatter's disease to be linked to the fracture. Incomplete fractures are usually treatable with the traditional RICE (rest, ice, compression, elevation) method, but complete/displaced fractures will most often require surgery to pin the tuberosity back in place. This occurs as a result of a violent contraction of the quadriceps muscles, most often as a result of a high-power jump. It has been established that the change in the velocity of fragments in time corresponds to the hyperbolic function a coefficient has been proposed to calculate the change in the velocity of potassium fluorphlogopite fragments break-off in time.X-ray of a 15-year-old male, showing an older avulsion fracture of the tibial tuberosity.Ī tibial tuberosity avulsion fracture is an incomplete or complete separation of the tibial tuberosity from the tibia. The experiment determined the velocities of individual burst fragments following an impact against hard-melting non-metallic silicate material, specifically potassium fluorphlogopite.
The video has been processed using frame-by-frame image analysis in ImageJ-FiJi software (TrackMate module). Velocity of burst fragments was determined on the basis of a video recording with Photron Fastcam SA5 high-speed camera. Four impact tests have been conducted with the following parameters: ball velocity 230 m/s and collision angle 90° ball velocity 120 m/s and collision angle 90° ball velocity 230 m/s and collision angle 30° ball velocity 120 m/s and collision angle 30°. The 23 mm steel ball (Steel 20) was used as a projectile.
Potassium fluorphlogopite targets have been shaped as flat plates sized 280x160x15 mm. The research aims at experimental determination of the fragments destruction velocity following an impact against hard-melting non-metallic silicate material (potassium fluorphlogopite). The models have been mostly designed to describe metallic materials. Various models descriptive of specific collision cases are used to predict the fragmentation parameters including the velocity of fragments. Determination of the velocity of individual fragments of a fragmented matter following an impact is necessary for studying the dynamic mechanical properties of materials.