Surgery – Instruments – Orthopedic instrumentation
Reexamination Certificate
2001-07-19
2004-01-13
Philogene, Pedro (Department: 3732)
Surgery
Instruments
Orthopedic instrumentation
C604S155000
Reexamination Certificate
active
06676663
ABSTRACT:
TECHNICAL FIELD
This invention relates to an applicator device for controllably injecting surgical cement into bones, particularly for use in percutaneous vertebroplasty, whereby the applicator device that allows the use of a per se conventional syringe body containing a pastous mass such as a bone cement.
BACKGROUND OF THE INVENTION
Pathological states affecting bones as for example the bone of vertebra of the backbone are rather common. In connection with vertebra, such pathologies may originate from a plurality of origins, the most frequent ones being bone fractures and pathological states such as tumors, osteoporosis etc. leading to at least a partial destruction of the bone structure which in turn results severe pain, in a compression of the spinal cord and may even lead to permanent incapacity of the patients.
Surgical techniques have been developed to provide a certain reconstruction or at least a certain stabilization of the affected bone by non-invasive surgery. These techniques comprise percutaneously applying a hardenable cement mass by injecting the mass into affected areas of the vertebra through a hollow needle of a syringe being introduced through an inner cavity of a previously placed puncturing stylet, the injection being controlled by monitoring the cement mass which may be isotopically marked, by X-ray monitoring means. In view that the cement mass must be injected into the vertebra itself and taking into account the highly dense nature of the cement masses used, high pressures are necessary to force the mass through the hollow needle and into the bone tissue of the vertebra, in this kind of surgery it is difficult to meter exact amounts, to avoid leaking of the cement into areas outside the vertebral area, as for example leaking into the venous locoregional region, the intradiscal region and/or even the pulmonary region, as such leakages may result dangerous and even fatal for the patient being treated. One conventional way of attempting to avoid the leakages, has been to use rather thick needles having rather wide inner channels. Although the use of such thick needles requires less force to be applied compared to the use of conventional needles, they do not permit sufficiently exact metering of the cement in addition to be rather invasive and not allowing accurate local application of the cement.
Applicator devices have been designed to overcome the aforementioned problems related to accurate metering and application of the cement such designs comprising screw means for pushing plungers into syringe-like bodies from which the cement mass is controllably expelled through a needle connected to an outlet of the syringe-like bodies.
Thus, EP-A-1074231 discloses a device for metering a surgical hardenable mass for vertebroplasty comprising a metering body, plunger with a screw-threaded shaft and a plunger head and a rotator knob, the shaft and plunger head being displaceable within the metering body, and a coupling for a manual pump for filling the hardenable mass into a metering body, such that, upon screwing the screw-threaded shaft into the metering boy, the plunger head expels the hardenable mass from the metering device through a hollow needle. This device, albeit allowing a rather accurate metering of a cement mass without requiring much force to expel said mass, has the disadvantages that the cement mass is in direct contact with the inside cavity of the metering body so that sterilization problems may arise and that, should, for example when the device has not been cleaned immediately after use, the cement mass hardens within the metering body and renders the whole device useless.
Spanish Patent EP-2121676-B1 discloses a support for syringes comprising a semicylindrical body having an annular end portion with a guiding block closing the, the guiding block having an inner path with an inner thread, a rotatable spin and a substantially conical end portion opposed to the annular end portion. The spin has an outer thread, a distal end passing through the inner path of the guiding block, and a proximal end protruding into the cavity of the semicylindrical body such that the spin is axially movable within the axial cavity when being rotated upon being screwed and unscrewed within the inner thread of the guiding block. The proximal end of the spin has a discoidal pusher. A per se conventional syringe may be inserted into the space between the conical portion and the discoidal pusher so that, when the spin is actuated, it pushes the plunger of the syringe into the syringe body so that the material contained in the syringe body is expelled. Whilst the applicator device disclosed in Spanish Patent EP-2121676-B1 allows the use of conventional plastic syringes so that hardening of a therein contained cement mass does not render the whole of the device useless, it has the disadvantage that the syringe is not really fixed at the open axial portion of said body, so that when high axial pressures are exerted on the syringe body, the body may deform break and/or be expelled from the semicylindrical body.
DESCRIPTION OF THE INVENTION
The present invention is aimed to overcome the aforementioned disadvantages of prior art applicator device by means of an applicator device for controllably injecting a surgical cement into bones, particularly in percutaneous vertebroplasty, the device comprising
an elongated body having a first end portion, a second end portion, a first side wall, a second side wall, and a bottom portion,
an axial space between the first side wall, the second side wall and the bottom portion, the axial space having a first end and a second end,
a guiding block closing the first end of the axial space and located at said second end portion, the guiding block having an inner path with an inner thread,
a rotatable spin having an outer threaded portion, a distal end emerging from the axial space by the first end of the axial space through the inner path of the guiding block, and a proximal end protruding into the axial space, the spin being axially movable within the axial space when being rotated within the inner thread of the guiding block, said proximal end pressing on a plunger into a syringe body when said pin is screwed into said axial space, and
a syringe holder compartment for holding the syringe body the syringe body having an open insertion end for insertion of the plunger and an outlet end with a tubular outlet.
According to the invention, the syringe holder compartment is a hollow body being releasably fastened by fastening means to said second end portion of said elongated body, and comprising an axial inner cavity being in axial alignment with said axial space, an open end for insertion of the syringe body by its outlet end, and an abutment end for abutment thereagainst of the outlet end of the syringe body, the abutment end having an opening for said tubular outlet to protrude out of the hollow body. The releasable hollow body has manifold advantages. Thus, it is a first advantage that the periphery of the syringe body is held within the axial cavity of the hollow body such that the wall avoids the syringe body to deform when the standard high pressures for injecting cement into bones are applied. Another advantage is related to the fact that, as well known, standard bone cements as those used in percutaneous vertebroplasty, harden and must harden rather quickly (6-8 minutes maximum) so that, when more than a cement volume of more than one syringe needs to be injected, it becomes essential that the subsequent syringe(s) may be mounted in the applicator device as quickly as possible. In accordance with the invention, the hollow body is that it may be rapidly released from the elongated body when the load of a syringe has been injected into the bone, a new syringe with a further load of cement may be inserted into the hollow body, and the hollow body with the new syringe may be rapidly mounted in the applicator. Still another advantage is that, to make the applicator device suitable for using syringes of different dimensions, a plurality of hollow
Higueras Antonio Pérez
Valdiviesa Tomás Martín
Bonderer David
Klauber & Jackson
Philogene Pedro
LandOfFree
Applicator device for controllably injecting a surgical... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Applicator device for controllably injecting a surgical..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Applicator device for controllably injecting a surgical... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3265206