Synonyms
Bone necrosis of the sesamoid bone
Introduction
Renander’s disease is a disease that leads to the death (necrosis) of bone or parts of bone. Renander’s disease specifically refers to the death of the sesamoid bone of the big toe. The basis is a so-called bone infarction, which leads to a reduced supply of nutrients from the blood and oxygen to the bone material. The poorly supplied bone tissue is finally broken down. This process is also known as avascular necrosis, as there is a lack of blood supply in these areas.
Causes
Bone necroses are classified according to the affected joint or bone on the one hand, and on the other hand, they can also be classified according to the cause. In the case of a dying bone or bone part, various triggers are possible. In the case of Renander’s disease, bone necrosis can occur after previous injuries or overloading.
In this case, one speaks of posttraumatic bone necrosis. Due to an injury and constant incorrect loading of the foot, the sesamoid bone of the big toe develops minimal tears, so-called microtraumas. These can remain permanently.
In addition to pain at this site, it is possible that the blood supply to the bone is impaired. This finally leads to the death of the following bone material. The bone is increasingly degraded.
Another possible cause is an existing inflammation. A wound can carry germs and cause an infection. They finally settle on the bone and multiply increasingly.
An inflammatory reaction develops on the bone and surrounding soft tissue structures, which can also hinder the blood supply to the sesamoid bone. This can develop into necrosis if the state of undersupply persists for too long. If infection-related necrosis is present, it is called septic bone necrosis.
Furthermore, there are rare cases in which no clear cause can be found. Neither an infection nor an injury has contributed to the undersupply of bone. In this case this is called aseptic bone necrosis.
Diseases such as sickle cell anemia, which is a hereditary change in red blood cells, can lead to aseptic bone necrosis. Systemic lupus erythematosus (SLE), a rare autoimmune disease that causes damage to the skin and various organs, is another trigger of this particular form of bone necrosis. Other factors can also lead to a reduced blood supply. These include diving, working in compressed air such as in tunnels or mining, chemotherapy, radiation, and various drugs such as cortisone.
