surgical technique addendum

Transcription

1 s h o u l d e r Solutions by Tornier Aequalis reversed II shoulder system surgical technique addendum

2 Aequalis reversed II threaded post baseplate surgical technique addendum s u r g i c a l t e c h n i q u e a d d e n d u m

3 Table of Contents t o r n i e r a e q u a l i s R E V e r s e d I I t h r e a d e d p o s t b a s e p l a t e Overview/Intended use... 4 Guide Pin Positioning... 4 Glenoid Depth Evaluation... 5 Reaming... 5 central hole Drilling... 6 Depth gauge... 6 counterbore drill... 7 Tapping... 7 Introduction of the Baseplate... 8 Peripheral Screw Drilling... 9 Peripheral Screw Fixation Sphere Fixation instrumentation

4 overview: This technique contains instructions for the use of the Threaded Post Baseplate, which is an expanded offering of the Aequalis Reversed II product family. The Threaded Post Baseplate is an alternative to the existing Aequalis Reversed II press-fit baseplate. The surgeon has to evaluate the bone quality preoperatively in order to decide if he uses the Threaded Post Baseplate or the Press Fit Baseplate. Intended use: Please refer to the Reversed II surgical technique for a complete list of indications. guide pin positioning: All steps prior to the positioning of the guide pin should be followed as they are described in the Reversed II surgical technique. The 2.5 x 200 mm guide pin should be positioned as described in the Reversed II surgical technique (Fig. 1). NOTE: It is recommended to stop drilling as soon as the far cortex is reached in order to produce an accurate depth measurement in the following step. Figure 1 4

5 Glenoid Depth Evaluation Once the pin is in place, the length of the pin inside the scapula is evaluated using the pin gauge. The pin gauge is slid over the 2.5 mm guide pin and the length of the pin inside the scapula is read using the end of the pin as a measurement marker to indicate the depth (Fig. 2). This evaluated length is an indication for the correct position of the pin. The desired position is slightly anterior, so that the threaded post can exit with its tip through the anterior cortical wall to ensure cortical fixation is achieved. Figure 2 It is recommended to reposition the pin anteriorly when the evaluated depth is significantly longer than 35 mm and repositioned posteriorly when it is significantly shorter than 25 mm. This will ensure that cortical fixation is achieved at the tip of the screw. NOTE: Standard baseplates are available in 30 and 35 mm post lengths. Baseplates with post lengths above or below these sizes are available upon request only. REAMING The glenoid is then reamed over the guide wire with the corresponding baseplate reamer (ø25 mm or ø29 mm) and peripheral reamer (ø36 mm or ø42 mm) as described in the Reversed II surgical technique (Fig. 3). Figure 3 5

6 central hole drilling The glenoid central hole is drilled over the guide wire using the cannulated ø6.5 mm drill bit. Laser marks can be used to help determine the final implant length (Fig. 4). Palpation of the drill bit tip can be performed to confirm the drill bit has exited the cortex. The drilling is performed under power over the guide wire. The drill depth depends on the previously evaluated pin depth (Fig. 5): If the pin depth evaluation is 25 mm or shorter, the drilling should continue until the drill penetrates the cortical wall to ensure the 30 mm threaded post can be fully inserted. If the pin depth is between 25 mm and 30 mm, the drilling should advance to at least 30 mm or until the drill exits the cortex. This will appropriately prepare the glenoid to receive the 30 mm length baseplate. If the pin depth is over 30 mm, the drilling should advance to at least 35 mm or until the drill exits the cortex. This will appropriately prepare the glenoid to receive the 35 mm length baseplate Figure 4 Figure 5 NOTE: 4, 5 and 6 mm drill bits are available for gradual preparation of the central hole, if desired (Fig. 6). The first drill bit is used over the initial guide pin. Increasing diameter drills are used until the final 6.5 mm drilling step is performed. DEPTH GAUGE If additional evaluation of the final implant length is required, the peripheral screw hole depth gauge can be used (Fig. 7). Figure 6 NOTE: To ensure an accurate evaluation of the final implant length, make sure the tip of the depth gauge is contacting the glenoid surface. Positioning the tip of the depth gauge inside hole will result in an incorrect evaluation. Figure 7 6

7 COUNTERBORE DRILL The starter hole is expanded using the cannulated ø8.2 mm counterbore drill bit under power (Fig. 8). If the pin is removed during the previous step, the drill is centered on the previous hole and performed free-hand. This will prepare the bone for the coated post section of the implant. Drilling should progress until the positive stop reaches the glenoid surface. Figure 8 TAPPING After drilling the central hole, the guide pin is removed and the tap is used in order to prepare the threads of the final implant. NOTE: Tapping is mandatory in order to prevent glenoid fracture Shown without depth stop Similar to the drill bit, there are depth laser markings on the tap. The tapping depth should be chosen similar to the depth of the drilled central hole. A depth stop can be placed at the desired position in order to stop the tapping at the desired depth (Fig. 9) For post lengths 25, 30, 35 and 40 mm, stop at the level of the corresponding laser mark. For lengths 45 mm and 50 mm stop at the level of the step on the tap, shown on Fig. 9. Shown with depth stop Figure 9 NOTE: Tapping has to be done manually using the Reversed II handle (Do not use with power). NOTE: The tap stopper can be Clicked to the next position, so it is important to stop once the tap stop is flush with the glenoid surface (Fig. 10). The tap stopper is not needed for 45 and 50 mm tapping. NOTE: When tapping, It is important to maintain alignment to the axis of the previously drilled hole. Figure 10 7

8 INTRODUCTION OF THE BASEPLATE The final baseplate is chosen according to the prepared hole (30 or 35 mm for standard implant) and the reamed glenoid surface (ø25 mm or ø29 mm). The glenoid baseplate is attached to the baseplate holder through its central hole using a screw in the central shaft of the handle. Care should be taken to ensure that the two pegs on the impactor seat properly into their respective holes on the implant baseplate (Fig. 11). The baseplate is carefully threaded into the prepared hole. It is important to continuously check the orientation of the baseplate relative to the prepared hole and reamed surface to ensure accurate implantation of the baseplate (Fig. 12). Figure 11 Once the baseplate is seated flush on the glenoid surface (Fig. 13), the baseplate holder is detached from the baseplate Figure 12 NOTE: The baseplate should be seated completely onto the prepared glenoid surface. Use three finger tightening technique to avoid over-tightening or excessive advancement of the baseplate into the subchondral bone. Gaps between the baseplate and glenoid surface should also be avoided. Figure 13 8

9 Surgical Surgical Technique Technique PERIPHERAL SCREW DRILLING Once the baseplate is implanted, the 4 peripheral holes are prepared using the ø3 mm drill bit and the locking screw drill guide from the Reversed II instrumentation (Fig. 14a). Figure 14a All 4 holes of the threaded post baseplate are multidirectional locking screws and can be angled up to 20 away from the central post and 0 toward the post. The screws can also be angled +/-20 parallel to the post (Fig 14b). The direction of the drill axis is chosen by free orientation of the drill guide. The ø3 mm drill bit is passed through the guide and the hole is drilled bicortically (Fig. 15). It is desirable to have the superior screw in the base of the Coracoid and the inferior screw in the pillar of the Scapula, where the best bone fixation of the screws can be achieved. +/-20 NOTE: It is important to avoid angling the drill guide and drill too close to the post in order to avoid any damage to the post and compromising fixation. Figure 14b The screw length is read directly on the drill guide by locating the laser mark on the drill through the window on the drill guide (Fig. 16). If desired, a standard depth gauge is available Figure 16 Figure 15 9

10 PERIPHERAL SCREW FIXATION After drilling each hole, the measured screws are inserted into the drilled hole and fully tightened with the 4.5 mm screwdriver (Fig. 17). The baseplate implantation is finalized once all screws are seated (Fig. 18) Figure 17 Figure 18 SPHERE FIXATION After implantation of the baseplate and screws, the sphere is impacted and screwed into the threaded post baseplate using the same technique described in the Aequalis Reversed II surgical technique (Fig. 19). All Reversed II spheres are compatible with the threaded post baseplate. NOTE: The threaded post baseplate contains 2 mm of lateral offset, therefore, there is always a gap of 2 mm between the sphere and the glenoid surface. Figure 19 10

11 Threaded Post Baseplate Implants Standard Implants # Description Quantity DWE730 ø25 x 30 mm 1 DWE735 ø25 x 35 mm 1 DWE830 ø29 x 30 mm 1 DWE835 ø29 x 35 mm 1 Single Use # Description Quantity DWD063** MWF715* ø2.5 mm Alignment Pin L200 mm (Sterile) ø2.5 mm Modified Guide Pin (Non-sterile) **Included in Rev II Single Use Instruments ** * Instrumentation YKAD987 # Description Quantity MWF713 Pin Gauge 1 MWF711 Drill Bit Dia MWF709 Drill Bit Dia MWF714 Tap 1 MWF716 Tap Depth Stop 1 MWF717 Drill Bit Dia. 4 mm 1 MWF718 Drill Bit Dia. 5 mm 1 MWF719 Drill Bit Dia. 6 mm 1 MWF710 Baseplate Holder 1 11

12 Us Headquarters Tornier, Inc Nesbitt Avenue South Bloomington, MN USA International Headquarters MANUFACTURER Tornier SAS 161 rue Lavoisier Montbonnot Saint Martin France +33 (0) Prior to using any Tornier device, please review the instructions for use and surgical technique for a complete listing of indications, contraindications, warnings, precautions, potential adverse events, and directions for use Tornier, Inc. All rights reserved. Aequalis, Tornier and are trademarks or registered trademarks of Tornier in the U.S. and other countries. Aequalis TM Reversed II Threaded Post Baseplate - Surgical Technique Addendum - UDXT145