Chandler's disease, also known as idiopathic avascular osteonecrosis of the femoral head (ANFH or ONFH), is a rare condition in which the bone cells in the head of the femur (FH) die due to lack of blood. This disease is caused when blood flow is reduced to the part of a bone near a joint. It is specifically unique because the femoral head is for some reason the only affected part of the body and rarely travels down to the main part of the femur. In 1948, F. A. Chandler did a multi-case review and first released his interpretations as Coronary Disease of the Hip. This term is now considered incorrect as it improperly describes the actual disease.
In current practice patients usually present with hip pain on the side with Chandler's disease. Since this is such a rare diagnosis some more conservative pain control methods are seldom used first before in-depth scans are used that lead to the diagnosis. Based on the staging of the dying bone typically dictates the course of treatment. Many of the more conservative treatments do lead to a whole hip replacement in the span of the patient's lifetime but there is promise of saving the dying bone or proper healing if caught early enough. At this time there are little research on curing the disease since it is not directly life-threatening and even the most invasive options lead to a moderate quality of life. Most of the research is more focused on finding if there is a combination of conservative treatments that together can replace more invasive treatment options as the preferred method of treatment in the later stages.
Signs and symptoms
Clinical presentation of Chandlers or ANFH typically is asymptomatic in the early stages. As the condition progresses on patients may develop groin pain that can radiate to the knee and/or ipsilateral buttock otherwise known as the buttock on the same side of the body. In the most severe untreated cases the patient may not be able to walk, stand, or sit due to the increased exposure of nerves to the dead parts of the bone. On physical examination, patients usually present with a limited range of motion at the hip and complain of pain particularly with forced internal rotation. Many people will not know they have it until further diagnostic scans. Those who have it will get diagnosed unless it spontaneously heals on its own which is uncommon. Patients usually go through a few rounds of treatment and testing before more in depth scans are ordered and a full diagnosis is made. Either that or a repeat scan can show degeneration prompting for more in depth investigation. The signs and symptoms of this condition are so similar to others that the more common conditions are treated for or ruled out first.
Etiology and pathogenesis
The current etiology or origin of this disease is unknown. Some studies theorized that bone remodeling is maintained in a microenvironment in the FH meaning that there is a greater local component to changes to the femoral head than the normal systemic way that bone remodeling is handled throughout the body. As a whole our body goes through bone remodeling using various hormones and glucocorticoids to balance the uptake and output of bone throughout the entire body. The local portion is considered to be controlled partially by inflammatory cells called cytokines and individual growth factors. The theory is that the local bone remodeling is malfunctioning and overpowering the systemic bone remodeling causing the FH to be highly susceptible to necrosis. Studies have determined that there are risk factors that are more than likely associated with the development of the disease but many of them are very broad and include large groups of people for example alcoholics, diabetics, and many other common core morbidities. Unfortunately, most are classified under idiopathic due to being unable to truly narrow down the origin of why it only happens to the head of the femur. What most clinicians observe is that the head of the femur seems to almost have a system of its own somewhat separate from the rest of the femur. There are many theories as to how the head of the femur dies unlike why it is happening.