According to the source, what was the medical condition of the doctor's nephew from Malegaon, and why did his family decide to visit Shirdi?

The nephew of the Malegaon doctor was afflicted with a bone-cyst, referred to as Hadyavran in the text, which is described as a most difficult and extraordinary malady. Chapter 34 explains that despite his uncle being a qualified doctor and trying various treatments with other physicians and surgeons, the disease showed no improvement. All native, foreign, and even surgical efforts were exhausted. With all medical remedies failing and the boy suffering immensely, the family heard about a great saint in Shirdi, Sai Maharaj. They learned that his Udi could cure even incurable diseases, so they decided to visit him and try this spiritual remedy as a final resort to avert the calamity.