PRIMARY POROUS PATELLA WITH TRABECULAR METAL. Surgical Technique

Transcription

1 PRIMARY POROUS PATELLA WITH TRABECULAR METAL Surgical Technique

2 1 SURGICAL TECHNIQUE FOR NEXGEN PRIMARY POROUS PATELLA * WITH TRABECULAR METAL CONTENTS PREPARE THE PATELLA Patella Reamer Technique Insetting Technique Universal Saw Guide Technique POST PREPARATION INSERTION * Indicated for use with bone cement in the US.

3 PREPARE THE PATELLA There are three techniques for Sharply dissect through the pre-patellar preparing the patella: bursa to expose the posterior surface of the Reamer technique patella. This provides exposure for affixing Insetting technique the anterior surface into the Patella Clamp. Universal saw guide technique Remove all osteophytes and synovial insertions from around the patella. Be careful not to damage tendon insertions on the bone. Use the caliper to measure the thickness of the patella (Fig. 1). Subtract the implant thickness from the patella thickness to determine the amount of bone that should remain after resection. PATELLA THICKNESS IMPLANT THICKNESS = BONE REMAINING Fig. 1 2 Note: At least 11mm of total bone must remain to allow for the implant peg. Implant Thickness

4 Patella Reamer Technique Total Resurfacing Procedure Use the Patella Reamer Surfacing Guides as templates to determine the appropriate size guide and reamer. Choose the guide which fits snugly around the patella, using the smallest guide possible (Fig. 2). If the patella is only slightly larger than the Total Surfacing Guide in the mediolateral dimension, use a rongeur to remove the medial or lateral edge until the bone fits the guide. Fig. 2 Insert the appropriate size Patella Reamer Surfacing Guide into the Patella Reamer Clamp (Fig 3). Turn the locking screw until tight. Fig. 3 3

5 Apply the Patella Reamer Clamp at a 90 Attach the appropriate size Patella Reamer angle to the longitudinal axis with the Patella Blade to the appropriate size Patella Reamer Reamer Surfacing Guide encompassing the Shaft (Fig. 6). Use only moderate hand articulating surface of the patella. Squeeze pressure to tighten the blade. Do not overtighten the blade. Insert the Patella Reamer the clamp until the anterior surface of the patella is fully seated against the fixation Shaft into a Drill/Reamer. Insert the reamer plate (Fig. 4). Turn the clamp screw to hold assembly into the Patella Reamer Surfacing the instrument in place. The anterior surface Guide. Raise the reamer slightly off the bone must fully seat upon the pins and contact and bring it up to full speed. Advance it the fixation plate. slowly until the prominent high points are Turn the clamp wing to the proper indication reamed off the bone. Continue reaming with for the correct amount of bone that is to moderate pressure until the step on the remain after reaming (Fig. 5). reamer shaft bottoms out on the clamp wing. Remove the Reamer Clamp assembly. 4 Fig. 4 Fig. 5 (Proceed to Post Preparation, page 7.) Fig. 6

6 Insetting Technique Use the Patella Reamer Insetting Guides as templates to determine the appropriate size guide and reamer. Choose the guide which will allow approximately 2mm between the superior edge of the patella and the outer diameter of the guide (Fig. 7). Insert the appropriate size Patella Reamer Insetting Guide into the Patella Reamer Clamp. Turn the locking screw until tight. pressure to tighten the blade. Do not overtighten the blade. Fig. 7 Fig. 8 Apply the Patella Reamer Clamp at a 90 angle to the longitudinal axis with the Patella Reamer Insetting Guide on the articulating surface. Squeeze the clamp until the anterior surface of the patella is fully seated against the fixation plate. Turn the clamp screw to hold the instrument in place. The anterior surface must fully seat upon the pins and contact the fixation plate. Turn the clamp wing to the inset position. Attach the appropriate size Patella Reamer Blade to the appropriate size Patella Reamer Shaft (Fig. 8). Use only moderate hand 5

7 Use the Patella Reamer Depth Stops to Universal Saw Guide Technique control the amount of bone to be removed Apply the Universal Patellar Saw Guide based on the constant 10mm thickness of in line with the patellar tendon. Push the the implants. The Depth Gauge Wing can be patella up between the jaws of the saw used instead of the stops to control the guide. Level the patella within the saw amount of bone remaining, rather than the guide jaws and use the thumbscrew to amount of bone removed. The procedure is tighten the guide. then the same as that described under Total The amount to be resected across the top of Resurfacing (page 3). Insert the reamer the saw guide jaws should be approximately assembly into the Patella Reamer Insetting the same on all sides. Check to be sure that Guide. Raise the reamer slightly off the bone the ten millimeter gauge does not rotate and bring it up to full speed. Advance it beneath the anterior surface of the patella. slowly until the prominent high points are If the gauge hits the anterior surface of the reamed off the bone. Continue reaming with patella as it is rotated, this indicates that at moderate pressure. Remove the Reamer least ten millimeters of bone stock will Clamp assembly. remain after the cut (Fig. 9). 6 Note: See your local Zimmer representative for a detailed surgical technique on the Zimmer Patella Reamer System. (Proceed to Post Preparation, page 7.) Fig. 9 Cut the patella flat so that a smooth surface remains (Fig. 10). Fig. 10

8 Note: The Primary Porous Patella Clamp may be used to fully seat the drill guide on hard sclerotic bone surfaces. 7 POST PREPARATION Center the appropriate Patellar Drill Guide over the resected patella surface with the handle on the medial side of the patella and perpendicular to the tendon. Press the drill guide firmly in place so that the teeth fully engage and the drill guide sits flat on the bone surface (Fig. 11). Drill the peg hole making sure the drill stop collar contacts the top of the drill guide (Fig. 12). Fig. 12 Fig. 11

9 INSERTION Apply cement to the Trabecular Metal and post while in a doughy consistency. Locate the drilled peg hole and use the Primary Porous Patella Clamp to insert and secure the Porous Patella in place. Fully open the jaws of the Patella Clamp and align the teeth to the anterior surface of the patella and the plastic ring to the posterior surface of the implant. Using the Patella Clamp, apply a significant amount of 8 pressure to the implant to fully seat the implant on the patella surface (Fig.13). Remove excess cement. Note: If the implant post begins to engage at an angle, the implant should be removed and repositioned perpendicular to the resected surface. Insert the patella again and reclamp, applying an even distribution of pressure on the patella surface. Fig. 13

10 IMPLANTS Cat. No. Description Standard Implant Set (Includes 1 each of the following) Primary Porous Patella, 32mm x 10mm Primary Porous Patella, 35mm x 10mm Primary Porous Patella, 38mm x 10mm Primary Porous Patella, 41mm x 10mm Micro Implant Set (Includes 1 each of the following) Micro Primary Porous Patella, 26mm x 10mm Micro Primary Porous Patella, 29mm x 10mm Micro Primary Porous Patella, 32mm x 10mm Micro Primary Porous Patella, 35mm x 10mm INSTRUMENTS Cat. No. Description Instrument Set (Includes 1 each of the following) Primary Porous Patella Provisional, 32mm x 10mm Primary Porous Patella Provisional, 35mm x 10mm Primary Porous Patella Provisional, 38mm x 10mm Primary Porous Patella Provisional, 41mm x 10mm Micro Primary Porous Patella Provisional, 26mm x 10mm Micro Primary Porous Patella Provisional, 29mm x 10mm Micro Primary Porous Patella Provisional, 32mm x 10mm Micro Primary Porous Patella Provisional, 35mm x 10mm Primary Porous Patella Drill Guide, 26mm x 10mm Primary Porous Patella Drill Guide, 29mm x 10mm Primary Porous Patella Drill Guide, 32mm x 10mm Primary Porous Patella Drill Guide, 35mm x 10mm Primary Porous Patella Drill Guide, 38mm x 10mm Primary Porous Patella Drill Guide, 41mm x 10mm Primary Porous Patella Drill Townley Femoral Caliper Universal Patellar Saw Guide Primary Porous Patella Clamp Primary Porous Patella Instrument Case Manufactured by Distributed by Please refer to the package insert for complete product information including contraindications, warnings, precautions, and adverse effects MZ Printed in USA 2001 Zimmer, Inc.