Why does an injury to a bone have a faster recovery/healing time when compared to a muscle or nerve cell?

Rich blood supply: Because of the lack of blood supply to cartilage, (a new technique to hasten healing of injuries is to introduce fresh blood flow into the area) whereas the marrow in bones actually produce red blood cells, and bones are actually a honeycomb like structure, and they are constantly being taken apart, and rebuilt, microscopic bit by bit injury to nerve - does not heal since nerve does not grow back.

Biology: Tissues in our bodies heal at different rates. Reasons for this are too extensive for 400 characters. Muscle heals relatively quickly due to good blood supply. Most bones will heal in about 6 weeks in a typical healthy adult (faster in kids with open growth plates, slower in older adults, diabetics, and smokers). Nerve tissue is the slowest healing tissue in our bodies.