Brief Answer:
Agent orange and Avascular necrosis

Detailed Answer:

Hello,

There are no studies that directly mention the causal association between agent orange and Avascular necrosis of bones.
However, there is a previous verdict that granted entitlement to service connection for avascular necrosis of the bilateral hips, to include as due to Agent Orange exposure.
Citation Nr: 0000     
Decision Date: 03/04/15
This is accessible from the va.gov website.

In that particular case, the petitioner's doctor claimed the positive association between Avascular necrosis and angioendotheliomatosis.
Angioendotheliomatosis is a condition where there is cell proliferation within blood vessels thereby obstructing blood flow, which in turn results in avascular necrosis.
There is a positive association between dioxin (a component of agent orange) exposure and development of angioendotheliomatosis. So they won the case that agent orange had been a causal factor to avascular necrosis.

The association between agent orange (dioxin) exposure and angioendotheliomatosis is very well described in Code of federal regulations (1985-99) and the Department of Veteran's Affairs Agent orange review, Volume 9.

Unfortunately, I am unable to share these links here as it is against the website's terms and conditions. You can look up these through a google search. Also, talk to your doctor and lawyer regarding this association and also about the previous verdict from Veterans Law Judge, Board of Veterans' Appeals.

Another study worth mentioning is 'Immunotoxicological Effects of Agent Orange Exposure to the Vietnam War Korean Veteranset.al published in Industrial Health 2003, 41, 158–166. This article mentions the development of avascular necrosis in veterans exposed to agent orange, However, this study does not affirm a causal relationship.

Hope I was able to help you. Please let me know if you have further questions
Regards,
Dr. Lekshmi

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