US Patent No. 6,309,396B1 G. David Ritland, M.D.
The Femur Finder is designed to direct the guide wire into the medullary canal. Do not use it to manipulate the fracture fragments, reduce the fracture, or direct the guide wire across the fracture site. INTRODUCTION The Femur Finder System is used in the management of femur fractures suitable for closed antegrade rodding. The technique requires less than a two centimeter incision to introduce the guide wire into the medullary canal. It can be used when the entry point is at either the piriformis fossa or the greater trochanter. The surgeon does not need to expose the neck or trochanter of the femur by deep dissection. With this system, introduction of the guide wire is a percutaneous procedure. This reduces the operative time required to place the guide wire. There is less weakening of the abductor muscles, postoperative morbidity, and pain. Guide Tube Handle Figure 1 Guide Rod - 2 - DESCRIPTION The Femur Finder (IMP #198) is made of stainless steel. It directs the guide wire into the medullary canal. It has three components as shown in Figure 1. 1. The guide tube is curved to allow the beveled tip to align on the femur neck tangent to the center line of the canal and place the entry point in the skin proximal and lateral to the tip of the greater trochanter. The beveled point will slide through the skin, subcutaneous fat, tensor fascia and abductor muscles with minimal dissection. The point itself solidly locks into the bone with hand pressure and prevents the guide wire from walking as it is drilled through the cortex. 2. The guide rod is a visual aid for aligning the path of the guide wire to the femur center line. The long portion of the guide rod is parallel to the path the guide wire takes as it exits the tip. The rounded end marks the end of the guide tube bevel as shown by the perpendicular line to be a visual aid for estimating the depth of penetration. 3. The handle allows one handed manipulation of the guide tube as it is advanced toward the femur.
ROOM SET-UP AND PATIENT POSITIONING 1. Position the patient supine with the ipsilateral arm flexed at the shoulder and the forearm supported over the chest. Traction and positioning of the legs is at the surgeons discretion. 2. The surgeon stands at the patient s shoulder facing the foot of the table. Set the video display so that the proximal femur image is at the BOTTOM of the screen and the distal femur is at the TOP (Fig. 2). This will assure that the right-left motion of the tip of the Femur Finder correlates with the right-left motion of its silhouette on the screen. All of the drawings in this protocol are oriented in this manner so the surgeon can become familiar with this view. 3. Proceed with skin prep and drape of choice. Figure 2-3 -
LOCATING THE INCISION Left Side of Monitor MONITOR Distal Right Side of Monitor Left Side of Monitor MONITOR Distal Right Side of Monitor 1. Apply traction to the leg and make preliminary adjustments to reduce the fracture. 2. From an AP view of the hip mark an X on the anterior thigh directly over the image of the piriformis fossa. Place a straight edge on the thigh passing through the X estimating the center line of the femur. Draw a center line on the anterior thigh from the X to the fracture site (line A, Fig. 3A). This locates the center of the medullary canal in the parasagittal plane. 3. Draw a line from the X perpendicular to the anterior center line around laterally on the thigh (line B, Fig. 3A). 4. Change to a lateral view and draw another line, as in step one, to mark the center line in the lateral plane (line C, Fig. 3B). Extend this line proximally to the iliac crest 5. Start the incision on the lateral centerline about 12 centimeters proximal to this intersection point with line B. Incise through the skin and subcutaneous fat down to the tensor fascia. Split the fascia and abductor muscles a bit to allow entry of the tissue protector. Insert the IMP Tissue Protector (#198-TP) into this tract. Bend the wings on the Tissue Protector to conform to the thigh (Fig. 4). Clip them to the drapes to keep the Tissue Protector in place for the rest of the procedure. It will protect the muscle from shredding by the reamers. Proximal Figure 3A Proximal Figure 3B Figure 4-4 -
IMP 3mm sterile guide wires (IMP 198-GW) are designed for use with the Femur Finder. The spade tip is shaped so it will not scrape on the curved lumen and release metal chips. Other brands of guide wires do not have this feature. Always use a new straight guide wire. Do not use a guide wire that is bent. Even if the bent wire can be forced into the lumen as it rotates it will rub and metal particles will be worn off the guide wire. INSERTING THE FEMUR FINDER AND GUIDE WIRE 1. While the surgeon proceeds with the above steps the scrub tech can load the power drill with a new IMP sterile 3mm guide wire (IMP #198-GW). Insert it so the etched band at the center of the wire is just exposed at the jaws of the chuck. This assures there will be enough wire protruding forward to penetrate ten centimeters into the femoral canal when the chuck is bottomed out on the Femur Finder. 2. Guided by an AP view of the femur centered on the piriformis fossa, insert the Femur Finder through the Tissue Protector and advance it towards the estimated location of the piriformis fossa. As a visual aid, align the guide arm parallel with the two center lines so the exiting guide wire will be tangent to the femur center line (Fig. 5). Hold pressure against the bone to prevent losing position of the bevel point. For the trochanteric approach to IM nailing use the same technique except locate the point of the Femur Finder so the guide wire is centered on the tip of the greater trochanter. Figure 5-5 -
Do not hammer the Femur Finder into the bone. Do not insert the Femur Finder into the femur to try to manipulate the bone to reduce the fracture. This instrument is not designed for that purpose. There is danger of splitting a fragment off the trochanter. 3. Remember: For a right femur fracture the lateral view will show the anterior surface of the femur on the left side of the screen and the posterior surface, (lesser trochanter) on the right side of the screen (Fig 3B, Fig 5). For a left femur fracture the lateral view will show the anterior surface of the femur on the right side of the screen and the posterior surface, (lesser trochanter) on the left side of the screen. 4. Verify the point location in both views. Maintain the point pressed against the bone with one hand and, with the other holding the power drill, slide the guide wire into the Femur Finder and advance it without rotating the drill until it emerges from the bevel and pushes against the femur (Fig. 6). Then start the power drill and drill the guide wire into the bone. Because the Femur Finder point is locked on the bone the guide wire tip will not tend to walk as it tries to get a bite on the slanted surface of the bone. Be sure to maintain the alignment of the guide wire on the center line as it advances. 5. Advance the guide wire until the chuck contacts the Femur Finder. Holding the guide wire in place at its proximal end, remove the power drill. Extract the Femur Finder. Careful! Don t pull out the guide wire too. 6. Done! The Femur Finder has done its job. 7. Proceed in the surgeon s chosen manner to advance the guide wire and reduce the fracture.* 8. Insert the exchange tube and replace the guide wire with the ball tip guide wire (IMP#198-BT). Proceed with opening the canal and reaming in customary manner. Figure 6 * The Ducharme Fracture Alignment Device (Cat. # 701) from IMP aids in reduction of the fracture. - 6 -
FEMUR FINDER STERILIZATION PROCEDURES Hi-Vac Sterilization: 1. Proper cleaning of the instrument is necessary. Ensure cannula of the Femur Finder is thoroughly cleaned with the specially designed IMP cleaning brush (Cat. # 399). Thoroughly wash and decontaminate the instrument. 2. Double wrap Sterilization Case (Cat. # 198-Case) containing Femur Finder and Tissue Protector with CSR wrap. 3. Run normal vacuum cycle for your institution. Minimum recommended parameters are: Time: 4 minutes exposure Temperature: 270 F (132 C) Pressure: 30 PSI Drying Time: 20 minutes Cool at room temperature Flash Cycle: 1. Minimum recommended cycle parameters for Sterilization Case containing Femur Finder and Tissue Protector unwrapped are: Temperature: 272 F (133 C) Time: 4 minute exposure Cool at room temperature - 7 -
Innovative Medical Products, Inc. US Patent No. 6,309,396B1 Femur Finder is a registered trademark of Innovative Medical Products, Inc. 6029.2M 2006 Innovative Medical Products, Inc. All rights reserved. 1/07 A GLOBAL LEADER IN PATIENT POSITIONING 87 Spring Lane, Plainville, CT 06062 PH: 860-793-0391 FAX: 860-793-8975 Toll Free: PH: 800-467-4944 FAX: 888-229-1452 www.impmedical.com