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
Ulnar collateral ligament injury of the elbow and extension. The posterior oblique originates at the medial epicondyle and inserts along the mid-portion of the medial semilunar notch. It applies more stability against valgus stress when the elbow is flexed rather than extended. The transverse ligament connects to the inferior medial coronoid process of the ulna to the medial tip of the olecranon. Since it is connected to the same bone and not across the elbow joint, the transverse ligament has no contribution to the joint’s stability. In most cases, a physician will diagnose an ulnar collateral ligament injury using a patient’s medical history and a physical examination