This invention relates to surgical instruments, more particularly to an arthroscopy or endoscopy portal maker. The invention comprises an apparatus and method that will provide a very accurate percutaneous incision in a living body for creating a portal for arthroscopic or endoscopic surgery.
The invention relates to a device for the creation of a precise working portal for arthroscopic surgery, endoscopic surgery or other surgical procedures using the aid of video technology to visualize internal anatomical structures. As minimally invasive surgery has evolved, numerous tools have been developed to assist in treating medical conditions that have previously been treated with open and more invasive techniques. Arthroscopic surgery of the knee is a common example of this surgery. Typically, the first step in arthroscopic surgery is to create a portal for the camera. This xe2x80x9cblindxe2x80x9d portal is made by palpating known anatomical structures near the desired location of the portal and making an incision. The camera is placed through this portal and the knee is inflated with fluid. Typically, next a spinal needle is percutaneously directed toward the area of pathology to identify the correct location of a xe2x80x9cworkingxe2x80x9d portal. The working portal will provide access for future instruments to be passed. A knife blade is than passed into the joint to approximate the plane of the needle. This approximation can lead to several problems. The knife can pass on a different plane, causing injury to vital structures. The knife blade can pass in a different plane, making placements of instruments difficult. Finally, if the knife blade does not pass completely into the joint, it can leave a tighter working portal which makes passing instruments more difficult as they get caught up in fat and synovium that lines the joint.
Other persons have attempted to design devices that would create an accurate portal. For example, U.S. Pat. No. 5,120,318 discloses a portal maker with a puncturing tool and a cannulated shaft having a circular cross section. The puncturing tool is hollow so it can accept a wire rod passing inside of it during one step of a disclosed procedure. U.S. Pat. No. 4,790,312 discloses a surgical instrument for operating percutaneously in a living body. It has a hollow handle and a an elongated shaft of circular cross section.
There is no single surgical instrument in the prior art that is able to successfully and accurately identify the proper location for and then make an unlined working portal in that exact location in a living being for preparation of arthroscopic or endoscopic surgery.
A sliding knife and needle assembly for creating a percutaneous incision or portal in a living body is disclosed. It comprises an elongate hollow rectangular handle having a closed first end, an open second end and a slot extending along one side, with the handle defining a first central longitudinal axis. A knife blade and introducer assembly is slidably housed inside the handle for sliding along the axis. The knife blade is substantially flat and rigidly attached to one end of the introducer. The introducer has a longitudinal bore which extends along a second axis parallel to the first axis. A locking button is attached to the introducer and extends through the slot in the handle. A needle is affixed to the first end of the handle and extends through the second axis and beyond the second end of the handle. The needle extends through the bore in the introducer. By this construction, the knife blade and introducer can be slid into and out of the handle along the first axis and locked in a retracted position wherein the knife blade is enclosed by the handle and slid to an extended position wherein the knife blade extends from and beyond the second end of the handle by releasing the locking button and sliding it along the slot.
In one embodiment, the needle is solid, preferably 18 to 22 gauge and has a first end affixed to the first end of the handle and a sharp second end that can be inserted through the skin and muscle of the living body.
Preferably, the handle is made of plastic and has a gripping surface on the outside proximate one end. The knife blade has an elongate cutting surface set at an angle with respect to the first axis. Accordingly, the cutting face has a cutting tip at one end. In one embodiment, the knife blade also has a bore coaxial with the bore in the introducer and along the second axis, and the knife blade bore extends through the angled cutting face near the tip. Preferably the locking button also retains the knife blade and introducer from sliding too far beyond the second end of the handle.
The invention also provides a needle and knife assembly for creating a portal for arthroscopic or endoscopic surgery comprising an elongate solid central needle having a second sharp free end and a first fixed end, and a substantially straight angled knife blade having an angled cutting end and a rear end. An introducer is affixed to the rear end of the knife blade and has a longitudinal bore through which the needle extends, with the bore sized so that the knife blade and the introducer are free to slide along the needle. A locking button is affixed to the introducer. An elongate hollow handle partially envelopes the knife blade and the introducer and has a first solid end to which said first fixed end of the needle is attached, a second open end and a slot along one side. The knife blade and the introducer are free to slide from a retracted position wholly inside the handle wherein only the needle protrudes from the first end of the handle to an extended position wherein the knife blade extends beyond the second end of the handle and is proximate the second end of the needle by releasing the locking button and sliding it along the slot.
In one embodiment, the needle and the bore in the introducer define a second axis, the centerline of the elongate hollow handle defines a first axis and the first axis and second axis are parallel. In an alternative embodiment, the first axis and the second axis are collinear. The handle may be either rectangular or cylindrical in shape.
The invention also provides a method of making a portal in a living body for arthroscopic or endoscopic surgery comprising slidingly positioning an angled flat knife blade and an elongated cannulated introducer into the hollow interior of an elongate handle, with the handle having a first open end and a second closed end and a slot extending along one side. The handle also has a needle with a sharp end extending outwardly from the first end, with the needle permanently affixed to the second end of the handle. The needle defines a longitudinal axis through the handle. The needle also extends through a bore in the cannulated introducer. The skin and muscle of the living body are punctured with the sharp end of the needle and the sharp end of the needle is inserted into the body at a desired location. Next, the knife blade and the introducer are slid along the longitudinal axis to an extended position whereby the knife blade creates a percutaneous incision in this skin and muscle proximate the needle by grasping and manipulating the locking button attached to the introducer. Finally, the surgeon simultaneously withdrawals the needle and the knife blade from the incision whereby an accurate portal is left in the body near the location at which the end of the needle has been inserted.
It is an object of the invention to provide a single surgical tool and method that will locate the proper location for an arthroscopic portal and also create a percutaneous incision at that location.
Further objects of the invention will be appreciated by review of the preferred embodiment and claims of the invention.