A fracture is classified when the integrity of the bone is compromised. A crack or break is synonymous with fracture. So many of my patients come in and when I ask about past history of fractured bones they say, “No, I just cracked it.” A break is a fracture, a cracked bone is a fracture. When there is a break in the skin along with a fracture this is determined to be an open fracture. In terms of concern for infection, there is no difference in diagnosis with a bone sticking out of the skin vs skin disruption and the break being deep and not protruding. Both are considered an open fracture. The distinction is important for antibiotic therapy to avoid bone infection (osteomyelitis.) This is very important in the outdoors for transport and the importance of expediting the transport depending on the severity of the potential fracture.
I will keep this as simple as possible. Inside bones, the bone marrow is a spongy substance where stem cells are born. Stem cells are immature red and white blood cells as well as platelets. When bones break they bleed and this can be a helpful assessment to determine if it might be broken. (Especially when you are days from transport.) If the area becomes very swollen and black and blue within 24 hours, there is a good chance you are dealing with a fracture.
The individual will clearly have pain and possibly swelling. It is a myth when someone says, “ I know I did not break it because I can move it.” There are so many supporting structures around bones that it is the vast majority that can move an extremity even when broken. I had a 60 year old male walk into the clinic unsupported with a fractured hip. So, nothing surprises me. Check with the non-injured side of the body and compare. Is there a change or deformity? Measure. If you do not have a measuring tape, use para-chord or string to measure the non injured circumference and then the injured. You can do this over time to see how much worse the swelling is. Check for cold of the skin farthest away from the fracture as well as sensation. You are checking for neuromuscular stability. Did the bone effect a major vessel or did it nick a nerve?