Bone resection method amd tools avoiding undercuts
Publication Date: 2008-Dec-11
The IP.com Prior Art Database
This disclosure covers a method for removing a section of bone during an orthopaedic procedure. It is primarily focused on the preparation of the femoral box cut for a PS Knee implant.
This disclosure covers a method for removing a section of bone during an orthopaedic procedure. It is primarily
focused on the preparation of the femoral box cut for a PS Knee.
Box cuts are prepared using a variety of methods and power tools.l • uses a notch guide and onhopaedic saws, either oscillating saws or reciprocating saws. OUf competitors --" .use reamers to
prep the box.
The problem with our current box prep is that when an oscillating saw is used to cut the base of the box it can produce undercuts (due to the fan shape the blade moves through and the lack of constraint from the instrumentation). Surgeons have a perception that this weakens the bone and can increase the risk of condylar
fracture. Figure 1 sketches out this issue, the black lines show typical 'overcuts'.
The solution is to develop a method that does not produce undercuts. A reaming option works in this respect but there is IP existing in this area.
My solution is based on using a circular cutter as shown in the process depicted in figure 2.
Step 1: Ajig is used to guide the saw along 3 straight cuts. The two outer marks define the box width, and a further line is marks the centre ofthe box width. A mechanical jig would be needed to guide the saw at this stage, for the purposes of this...