A few days later, a soft callus will form from the fracture hematoma and fibers of collagen start to appear. A type of cartilage called fibro cartilage will be created and it causes the callus to be tougher which bridge the gap between the two pieces of bone. Lastly, osteoblasts play a role in turning the callus into bone callus which provides necessary protection to the bone until it finishes healing. Osteoclasts and osteoblasts spend months remodeling the fractured bone by continually creating hard bone from the callus. These cells also decrease the callus and eventually returning the shape of the bone to its original state. However, this is not always the case as severe traumas may cause broken bones to heal in an abnormal way such as a misaligned bone.
There are four types of trauma affecting the skeleton: partial to complete break of a bone, dislocation of joints, and disruption of nerves as well as artificially induced abnormal shape of a bone. Accidents and therapeutic practices can affect the conditions of bones and may result in skeletal traumas. Abnormal stress on bones can cause bent bones; and in a young person, bending fractures may produce an incomplete break in the long bone. This condition is called “green stick fracture” and this type of fracture can heal with little evidence of a break. Fatigue fracture, on the other hand, is an incomplete fracture involving “only a portion of the cross sectional plane of a bone”. The different types of fractures will result in the different types of healing: if angulation has occurred in a healed bone, there will be compensatory remodeling. In this case, the skeletal bone (once broken) will appear to be thicker on the concave side of the angulated bone.
If a limb-for example- fractures and gets infected, disruption of blood supply to the bone may occur. And this may lead to the death of the tissue which gives rise to osteoclastic resorption, cutting the blood supply to the bone. A new sheath of bone will form around the dead tissue and this can be identified on a skeleton. Blood supply to bones is very important, if there is interruption in blood supply to a healing bone, it may result in the abnormal shortening of the bone. Misalignment of a fractured bone (which can cause premature degenerative change in joints) is another feature that can be seen on a skeleton.
Another obvious trace left on the skeleton by traumas is myositis ossificans traumatica: muscle tissue responds to traumas by producing bone in the muscle tissue. This formation of bone from muscles become part of the existing bone tissue and it can be clearly identified on a skeleton.
Identification of traces on a skeleton from trauma may sometimes not be easy as fractured bones may heal back to its original state. However, the abnormality of healed bones is usually spotted if the individual has once undergone severe injury. Proper analysis and observations must still be done in order to recognize the type of trauma found.
Reference:
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Ortner, Donald J.(2003). Identification of Pathological Conditions in Human Skeletal Remains.2nd ed.available from: assessed date: June 2, 2009
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Lamb,Robert.(2008) How do Broken Bones Heal. available from: assessed date: June 2, 2009