From what it looks like you were requesting service connection for arthritis of the ankles. The examiner stated that there was no medical evidence to support ankle injuries that would have caused the arthritis during your service. You didn't take the x-rays they had requested for you.
You then stated: "I have service treatment records proving the diagnosis of shin splints, stress fractures, posterior tibial syndrome, and issuance of arch supports due to injury from running which started in boot camp and continued throughout my active duty." Question #7, this is a standard question on the DBQ. Just cause they said no, its probably because those medical issues aren't involved with the your ankle.
How does shin splints, stress fractures posterior tibial syndrome and arch supports cause arthritis in your ankles? I could see you requesting S/C for those specific diagnoses. If you can provide a medical opinion stating that these issues caused your arthritis in ankles, then that would be the best evidence.
Hope it works out for you.