Limb infarction

A limb infarction is an area of tissue death of an arm or leg. It may cause skeletal muscle infarction, avascular necrosis of bones, or necrosis of a part of or an entire limb.

Affected tissues

The major tissues affected are nerves and muscles, where irreversible damage starts to occur after 4–6 hours of cessation of blood supply.

Skeletal muscle, the major tissue affected, is still relatively resistant to infarction compared to the heart and brain because its ability to rely on anaerobic metabolism by glycogen stored in the cells, which may supply the muscle tissue long enough for any clot to dissolve, either by intervention or the body's own system for thrombus breakdown. In contrast, brain tissue (in cerebral infarction) does not store glycogen, and the heart (in myocardial infarction) is so specialized on aerobic metabolism that not enough energy can be liberated by lactate production to sustain its needs.

Bone is more susceptible to ischemia, with hematopoietic cells usually dying within 12 hours, and other bone cells (osteocytes, osteoclasts, osteoblasts etc.) within 12–48 hours. On the other hand, it has better regenerative capacity once blood supply is reestablished, as the remaining dead inorganic osseous tissue forms a framework upon which immigrating cells can reestablish functional bone tissue in optimal conditions.