Periostitis blade of a horned dinosaur. Periostitis Periostitis, also known as periostalgia, is a medical condition caused by inflammation of the periosteum, a layer of connective tissue that surrounds bone. The condition is generally chronic, and is marked by tenderness and swelling of the bone and pain. Acute periostitis is due to infection, is characterized by diffuse formation of pus, severe pain, constitutional symptoms, and usually results in necrosis. It can be caused by excessive physical activity as well, as in the case of medial tibial stress syndrome (also referred to as tibial periostalgia, soleus periostalgia, or shin splints). Congenital infection
Medial knee injuries been reported that an isolated grade III sMCL tear will show an increase in medial compartment gapping of 1.7 mm at 0° of knee flexion and 3.2 mm at 20° of knee ﬂexion, compared to the contralateral knee. Additionally, a complete medial ligamentous disruption (sMCL, dMCL, and POL) will show increased gapping by 6.5 mm at 0° and 9.8 mm at 20° during valgus stress testing. Pellegrini-Stieda syndrome can also be seen on AP radiographs. This finding is due to calcification of the sMCL (heterotopic ossification) caused by the chronic tear of the ligament. Magnetic resonance imaging (MRI) can be