I was installing drywall last thursday 2/23/12 and ran a screw into my finger. the screw entered my finger about a half of an inch since then the tip of my finger is numb

A : A screw is different from other objects that puncture because of its threads. The threads are designed to bite and hold the material. In the case of a finger, it will grab and twist whatever is in its path. You probably twisted and likely tore the nerve to the finger tip, called a digital nerve. Depending on where it entered your finger, you may have hit one or both of the main nerves. Out toward the tip, however, the nerves divide into 3 main branches and many smaller branches. There are 3 main classes of nerve injuries: 1. Neurapraxias--these injuries involve compression, stretching, or bruising of the nerve, but the fibers are intact. The nerve can recover, usually within 3 months. 2. Axonotmesis--the main nerve is intact, but the inner fibers (axons) are broken. The fibers have to regrow. They take a month to get started and grow about 1mm/day or around 1 inch per month. On the finger, recovery is usually within 3-4 months, but it may not be "normal" again. 3. Neurotmesis--the whole nerve is broken. The nerve will have to regrow, but may get "lost" and form a ball of painful nerve endings, called a neuroma. In the finger, there are a lot of places the nerve can go, so it doesn't always get lost, but there is also very little tissue to pad the area if a neuroma does develop. The best way to know the extent of injury is to see a hand surgeon. Some nerve injuries will do better with early repair, usually less than 2 weeks after injury. Some injuries are unrepairable or do not require repair. Some can be reconstructed later if problems develop. More importantly, this is considered a dirty wound. If you have not had your tetanus vaccine updated within 5 years, you should get a new one. The wound also should be carefully cleaned and monitored for infection. Sometimes a short (usually 3 day) course of antibiotics can prevent infection.