Certain medical procedures, such as osteosynthesis, are performed to stabilize and join bone segments to each other. Such procedures use stabilizing members such as rods or metal plates that are coupled to the bone segments by fixation elements such as bone screws, tacks, rivets, etc. Prior to the insertion of the bone screws into the bone segments, holes are pre-drilled into the bone segments using a surgical drill.
Various surgical drills are currently in use that facilitate the user to drill at many speeds from several rpms up to and possible exceeding 90,000 rpms. Because of the varying speeds, the drill can behave like a milling tool and cuts into the wall of the hole thereby unintentionally and undesirably widening the diameter of the hole. This cutting effect can be compounded by chatter, vibration, axial torsion by the user, and bone quality, each of which can cause the drill to counter rotate (i.e. wobble) about a center axis of the hole. In some cases, the hole diameter increases up to 30% of the desired hole diameter. Moreover, because of the high speed in which such drills operate, heat can build up thereby causing thermal damage in the bone segments. Therefore, current drill bits not only have problems with creating repeatable hole sizes but also harm the surrounding bone while the holes are being formed. For at least these reasons, the bone screws used during osteosynthesis fixation are at risk to a degraded performance due to the unintentional loss of bone caused by standard drill bits.
USPTO Backgrounds
USPTO Backgrounds