What was the specific ailment of the doctor's nephew, and why was it considered so untreatable before they went to Sai Baba?

According to Chapter 34, the nephew's ailment was a bone-cyst, referred to in the text as Hadyavarn. It was considered an exceptionally difficult and untreatable malady because it resisted all forms of medical intervention available at the time. The text explicitly states that numerous treatments were attempted by the boy's uncle, who was a qualified doctor, as well as his physician friends and even expert surgeons. All efforts, including both 'native and foreign treatments' and surgery, were exhausted without any success. The disease showed no improvement, leading the medical experts to feel helpless and leaving the family in great distress before they heard of Sai Baba's spiritual healing powers.