the small bone-like balls forming underneath your skin also called crystals are the result of having too much uric acid present at your blood. i think you're suffering gout arthritis.
GOUT can usually be successfully treated by eliminating causes and taking medications to relieve symptoms. However, if gout symptoms have occurred off and on without treatment for more than 10 years, uric acid crystals may have accumulated in the joints to form gritty, chalklike nodules called tophi. If tophi are causing infection, pain, pressure, and deformed joints, and medications have been unsuccessful in shrinking and eliminating the tophi, your health professional may recommend surgery (excision) to remove them.