1. Technical Field
The present disclosure relates generally to methods and instrumentation for manufacturing an implant, and more particularly to methods and instrumentation for manufacturing and inspecting an intervertebral implant formed from cadaveric human or animal bone.
2. Background to Related Art
Intervertebral implants which are formed from cadaveric human or animal bone (xe2x80x9cbonexe2x80x9d) are well known in the art. Intervertebral implants formed of bone having a threaded dowel configuration, i.e., cylindrical, are also well known. The manufacturing or machining of a threaded intervertebral bone dowel is an involved process which includes at least a drilling or coring step, a milling step, a tapping step and a threading step. Due to the anatomical limitations of bone, each of the manufacturing steps must be precisely performed to produce a dowel having the requisite dimensions suitable for implant use. Typically, the entire manufacturing process is performed before the dowel is evaluated or inspected for suitability for implant use. Thus, where donor bone is not suitable for dowel manufacture or the donor bone has been improperly machined, much time and effort is needlessly wasted in performing additional manufacturing steps on a dowel which will never be useable as an implant.
Accordingly, a continuing need exists for methods and instrumentation for precisely manufacturing a bone dowel from a bone and for quickly identifying unsuitable bone early in the machining process to avoid undue waste of time and effort.
In accordance with the present disclosure, instrumentation for manufacturing a bone dowel from human or animal cadaveric bone and instrumentation for evaluating the suitability of the bone and/or dowel for implant use after each step of the manufacturing process is provided. Such instrumentation for manufacturing a bone dowel includes a blanking or coring apparatus, a milling apparatus, a threading apparatus and a tapping apparatus. A series of gauges are provided to inspect and determine the suitability of the bone dowel at each step of the manufacturing process. By inspecting the dowel being manufactured after each step of the manufacturing process, time and effort which is needlessly wasted during completion of the manufacturing of dowels which are unsuitable for implant use (due to unsuitable bone and/or inaccurate machining of bone) can be avoided.
Instrumentation for more accurately positioning bone and the partially manufactured dowel into the instrumentation for machining the dowel is also provided. Such instrumentation includes a gauge for positioning a piece of bone in relation to the coring apparatus, and mounting blocks for securing the partially manufactured dowel in relation to the milling, threading and tapping apparatus.