Surgery – Instruments – Orthopedic instrumentation
Reexamination Certificate
1999-07-02
2001-02-06
Smith, Jeffrey A. (Department: 3732)
Surgery
Instruments
Orthopedic instrumentation
C606S062000
Reexamination Certificate
active
06183470
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to instrumentation used during the implantation of prosthetic joint components and has specific relevance to a device which reduces the pressure within an intramedullary canal for the prevention of embolisms during surgery.
BACKGROUND OF THE INVENTION
During total joint arthroplasty, instrumentation is used by the surgeon to align various cutting or milling guides relative to the bone and the natural joint line. This instrumentation is well known in the art and need not be discussed in any detail here. In general, there are two classes of instruments for use during surgery, intramedullary and extramedullary. Extramedullary instrumentation is design to be position outside of the patients bone and is usually affixed to the patients limb by a series of straps or pins. Intramedullary devices are designed to be positioned directly within the medullary canal of the bone and generally include an elongate rod which is pushed into the medullary canal. Since the intramedullary instruments are positioned within the bone to receive the joint, they are generally considered more accurate than extramedullary instrumentations.
However, one draw back to the use of intramedullary instrumentation is the potential to cause fat cells within the medullary canal to be displaced during insertion of the intramedullary rod of the instrument. This issue becomes especially problematic if a bi-lateral knee procedure is being performed which would require an intramedullary rod be inserted into the medullary canal of both femurs and both tibial. To reduce the concerns discussed above, surgeons often choose to use extramedullary instrumentation or to perform surgery on one knee at a time. By delaying a needed surgery on the other malfunctioning knee, the patient is required to undergo two separate surgery sessions.
The use of stemmed provisional implant to test the fit and position of the final implant also may further add to the build up of pressure within the femoral canal. It would not be unusual for a stemmed tibial and femoral provisional components to be inserted into the intramedullary canals of the prepared tibia and femur multiple times during a surgery to test the fit and anatomic functionality of the final implant. The stemmed components may create a build up of pressure within the intramedullary canal. As it is impossible to replicate these components in an extramedullary solution, the surgeon may be forced to delay the operation on the patients second knee if stemmed components will be required.
SUMMARY OF THE INVENTION
The invention herein describe reduces the concerns expressed above associated with the use of intramedullary instrumentation by providing for the reduction of pressure within the medullary canal as the intramedullary instrument is inserted. Specifically, in the preferred embodiment a sleeve having a proximal end connected to a vacuum source is fitted over the intramedullary rod so that as the rod is inserted into the intramedullary canal, the pressure within the canal is reduced to thereby reduce the magnitude of cells released into the blood stream. In order to draw air from the medullary canal, the proximal end of the sleeve includes a gasket which seal against the intramedullary rod causing the air to be drawn only from the distal end of the sleeve. In an alternative embodiment, an air passage is provided directly through the instrument with the exposed end of the instrument being connected to a vacuum source.
Regarding the provisional instruments, the purpose behind such instruments is to provide the surgeon the proper feedback to ensure that the final implant will fit properly within the prepared bone. Therefore, it is impractical to provide a sleeve about the provisional stems as it would add to the outer diameter of the provisional. Therefore, this invention contemplates providing a set of provisional stems having an air passage provided therethrough for connection to a vacuum source.
Accordingly, it is an object of this invention to provide for instrumentation for use in orthopaedic surgery having an air passage or vent means for connection to a vacuum source to enable the intramedullary pressure to be reduced as the instrument is inserted therein.
Another object of this invention is to provide for a sleeve for accommodating an intramedullary rod of an orthopaedic instrument, wherein one end of the sleeve is connected to a vacuum source and the distal end include slots forming a vent.
Yet another object of this invention is to provide for instrumentation for use in orthopaedic surgery having an air passage or vent means formed through the instrument for connection to a vacuum source to enable the intramedullary pressure to be reduced as the instrument is inserted therein
Still other objects of the invention will become apparent upon a reading of the following description taken with the accompanying drawings.
REFERENCES:
patent: 5192282 (1993-03-01), Draenert
patent: 5312408 (1994-05-01), Brown
patent: 5707374 (1998-01-01), Schmidt
patent: 5766180 (1998-06-01), Winquist
patent: 5814049 (1998-09-01), Pratt et al.
patent: 6019761 (2000-02-01), Gustilo
patent: 1806654 (1993-04-01), None
Booth, Jr. Robert E.
Stalcup Gregory C.
Bristol--Myers Squibb Company
Dawson Todd A.
Smith Jeffrey A.
LandOfFree
Instrumentation for the prevention of embolisms during total... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Instrumentation for the prevention of embolisms during total..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Instrumentation for the prevention of embolisms during total... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608173