Biomet Large Cannulated Screw System

Transcription

1 Biomet Large Cannulated Screw System s u r g i c a l t e c h n i q u e A Complete System for Simplified Fracture Fixation 6.5mm & 7.3mm

2 The Titanium, Self-drilling, Self-tapping Large Cannulated Screw System 6.5mm 20mm Thread Length 7.3mm 16mm Thread Length 7.3mm 32mm Thread Length 13mm Titanium Washers Features: Self-drilling, Self-tapping Flutes Eliminates need to drill Eliminates tapping Reverse-cutting Flutes Facilitates screw removal 3.5mm Cannulation Accommodates 3.2mm guide wire for precise placement Titanium Alloy Greater torque strength MRI & CT compatibility Rigid 3.2mm Guide Pin More accurate screw placement Reduces risk of guide wire bending or breakage

3 Indications Femoral Neck Fractures Tibial Plateau Fractures Intercondylar Femur Fractures Ankle Arthrodesis Other indications include: Slipped capital femoral epiphyses Pediatric femoral neck fractures Sacroiliac joint disruptions Subtalar arthrodesis Adjunct to compression screw/plate in hip fracture 1

4 Operative Technique Patient Preparation The patient is placed on the fracture table in the supine position. The opposite hip and lower extremity are positioned to allow radiographic visualization of the fractured hip with the image intensifier in both A/P and lateral planes. The affected hip is then gently reduced with traction and internally rotated. Any varus deformity greater than 15 should not be accepted. The hip is then prepped and draped in the usual manner, using a sterile technique. Open Technique Surgical Exposure A guide pin placed externally on the anterior surface of the hip may be used as a template to determine the appropriate location for the incision. When viewed under image intensification this template guide pin should lie adjacent to the inferior aspect of the femoral neck advancing into the femoral head. A 5cm incision is made over the lateral aspect of the hip extending from the flare of the greater trochanter distally. The incision is carried sharply down through the skin and subcutaneous tissue to the vastus lateralis. The vastus lateralis is retracted anteriorly and split. Muscle tissue is stripped free from the femur and a Bennet retractor is placed around the femoral shaft exposing its lateral aspect (Fig. 1). Figure 1 The cannulated screws are to be introduced at or above the level of the lesser trochanter at an angle of 135 to prevent the formation of stress risers. Caution: The potential for post-operative femoral fracture in the subtrochanteric region increases substantially when screws are introduced below the level of the lesser trochanter at angles exceeding

5 Open Technique Placement of the Guide Pins Step 1 The level of the insertion of the first guide pin is checked by placing a guide pin over the femur using the image intensifier (Fig. 2). Figure 2 Step 2 A 4.3mm drill hole is made in the lateral cortex of the proximal femur at the level of insertion of the first guide pin. This is usually at the level of the lesser trochanter (Fig. 3). Step 3 A guide pin is then inserted into the pre-drilled hole, either free-hand or with the aid of the angle guide, at approximately 135 angled to the shaft or parallel to the femoral neck. Aided by the image intensifier, the guide pin is then driven into the femoral neck and head with a mallet. The guide pin is placed into the level of the subchondral bone (Fig. 4). Note: Be careful not to penetrate the joint with the guide pin. Figure 3 Step 4 At least two additional guide pins are placed into the femoral neck and head through the angle parallel wire guide either with a mallet or a wire-driver drill. The image intensifier is also used for pin positioning (Fig. 5). Note: It is important to stop these pins short of the hip joint in the subchondral bone. Figure 4 Figure 5 3

6 Open Technique Measurement After correct placement of the guide pins within 5mm of subchondral bone, the fixed angle guide is removed and the guide pin depth gauge is slid over the guide pin down to the surface of the femur. The length of the screw to be used is then read on the gauge at the end of the guide pin (Fig. 6). This measurement is done on each guide pin individually. Figure 6 This brochure is presented to demonstrate the surgical technique utilized by Mark A. Klaassen, M.D., F.A.C.S., Elkhart, Indiana. Biomet, as the manufacturer of this device, does not practice medicine and does not recommend any particular surgical technique for use on a specific patient. The surgeon who performs any implant procedure is responsible for determining and utilizing the appropriate techniques for implanting the prosthesis in each individual patient. Biomet is not responsible for selection of the appropriate surgical technique to be utilized for an individual patient. 4 Biomet is a registered trademark of Biomet, Inc.

7 Open Technique Cannulated Screw Insertion The proper length cannulated lag screw is then placed over the guide pin and inserted either with power using the screwdriver shank (P/N ) attached to the power adaptor (P/N ), or manually with the screwdriver shank attached to the T-handle (P/N ). Figure 7 Note: The position of the guide pin must be frequently checked using the image intensifier during screw insertion to assure that the guide pin is not advancing with the screw. The inferior screw adjacent to the inferior cortex is advanced first until the head of the screw is within 1cm of the lateral cortex. The remaining two screws are then also inserted and advanced to within 1cm of the lateral cortex (Fig. 7). Final Tightening In order to prevent varus angulation, the anterior and posterior screws should be tightened before the inferior screw. The screws should be advanced alternately several turns at a time until they are completely seated tight. The inferior screw is then tightened. Final seating of the screw should always be performed manually, one half turn at a time, alternating sequentially between each of the three pins until the head of each screw has made solid contact with the lateral cortex (Fig. 8). Figure 8 Once correct placement of the screws and reduction of the fracture has been confirmed under image intensification, traction is released and the hip is rotated through the full range of motion. This is performed while viewing the A/P and lateral image to assure that there has been no penetration of the joint space. The wound is then thoroughly irrigated and closed in the usual manner. 5

8 Percutaneous Technique Guide Pin Insertion Step 1 Use the guide wire and image intensifier to determine optimal skin incision. Insert the percutaneous sleeve assembly through a stab incision and through the soft tissue to the bone. Remove the trocar (P/N ). A 3.2mm x 9" guide pin (P/N ) is driven across the lateral cortex and into the femoral neck. The position of the guide pin must be determined in the femoral neck. The position of the guide pin must be checked during the procedure to assure that the pin is intraosseous, advancing toward the femoral head. The guide pin should be ideally positioned adjacent to the inferior cortex of the femoral neck at an angle of 135 to the femoral shaft (Fig. 9). The angle may vary with indications and fracture patterns. The guide pin is advanced until the tip is within 5mm of subchondral bone. Confirm final position of guide pin under both A/P and lateral image. Multiple pins can be placed parallel by using a fixed angle guide and slightly increasing the incision. Caution: Avoid perforation of the femoral head with a guide pin. When a guide pin penetrates the joint space, and a cannulated screw is inserted over the guide pin, a possibility exists that the cannulated screw will follow the path of the original guide pin and penetrate the joint space. A guide pin that has penetrated the joint space must be removed and reinserted in a different position. Figure 9 Figure , Protection Sleeve , Guide Pin Sleeve , Trocar 6

9 Measuring for Screw Length Step 2 Remove the guide pin sleeve and slide the tapered end of the cannulated screw measuring device through the protection sleeve to the bone. Screw length is read directly off the gauge at the end of the guide pin (Fig. 11). Inserting the Screw Figure 11 Step 3 The proper length cannulated screw is placed over the guide pin through the protection sleeve and inserted either with power using the screwdriver shank (P/N ) attached to the power adaptor (P/N ), or manually with the screwdriver shank attached to the T-Handle (P/N ). Final seating of the screw should be done manually using screwdriver shank (P/N ) and T-Handle (P/N ) (Fig. 12). Figure 12 7

10 Screw Removal Screw removal should always begin manually. Once started, screws may be removed either with power using the screwdriver shank (P/N ) attached to the power adaptor (P/N ), or manually with the screwdriver shank attached to the T-Handle (P/N ). Enhance the grip of the screw by inserting the guide wire into the cannulated screw prior to removal. The screw can also be localized by using the image with guide wire for removal. However, the screwdriver must be fully engaged before removal. Caution: Do not use pliers or similar devices to grip the screw head as this will damage the screw and could lead to head breakage. If the cannulated screw becomes damaged or removal becomes difficult, the easy out extractor (P/N ) should be used for screw extraction. The easy out extractor must be used manually in conjunction with the T-Handle (P/N ). The extractor tip is inserted through the head and down the center of the cannulated screw. The extractor is turned counterclockwise while applying firm forward pressure. The easy out extractor cuts into the cannula of the screw shaft to facilitate removal. The easy out extractor may be used even if the head or shaft of the screw is not intact (Fig. 13). If the cannulated screw cannot be removed with the easy out extractor, the trephine set may be used as indicated. The screw head must be removed prior to beginning this procedure: Figure Place the trephine (P/N ) over the screw. Drill down to the threads of the screw, then withdraw the trephine. 2. Slide the bushing (P/N ) over the screw shaft, down to the top of the screw threads. 3. Use the secondary trephine (P/N ) to drill over both the bushing (P/N ) and the threads of the screw, down to the tip of the screw. Reverse the drill and the whole assembly will come out. 8

11 Instruments I K M N A B C D E F G H J L Large Cannulated Screw Instrumentation K. Fixed Angle Guide B. Guide Pin Depth Gauge D. Screwdriver Shank I. T-Handle J. Power Adaptor C. Cannulated Countersink H. 7.3mm Cannulated Tap G. 6.5mm Cannulated Tap N. 3.2mm Trocar M. Guide Pin Sleeve L. Protection Sleeve Disposable Instrumentation A. Threaded Tip Guide Pin 3.2mm x 9" E. Easy Out Extractor F. 5.0mm Cannulated Drill Modular Sterilization Case 7.3mm Cannulated Screw Instrument and Implant Case Instrument Case Only Additionally Available Trephine mm I.D. Bushing (for use with 7mm Trephine) Secondary Trephine mm I.D. Dye Injector

12 Ordering Information Biomet 6.5mm Titanium Cannulated Cancellous Hip Screw 20mm Thread Length Part No. Size mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm Biomet 7.3mm Self-drilling, Self-tapping Cannulated Screw 16mm Thread Length Part No. Size mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm Part No. Biomet 7.3mm Self-drilling, Self-tapping Cannulated Screw 32mm Thread Length Part No. 7.3mm Titanium Washer Size mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm Part No. 6.5mm Titanium Washer For use w/ above screws in osteoporotic bone 13mm O.D For use w/ above screws in osteoporotic bone 13mm O.D. Additionally Available: 7.3mm Fully Threaded Cannulated Screws mm P.O. Box 587, Warsaw, IN Biomet Orthopedics, Inc. All Rights Reserved web site: Form No. Y-BMT-627/053100/M