OPERATIVE TECHNIQUE TREGOR® STANDARD – TREGOR® WITH 3 BLADES

TREGOR® + Cementless Dual Mobility Acetabular System

DOC2581

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The acetabular cup instrumentation is accompanied by a set of reamers with odd diameters ref. A34055 or even diameters ref. A34054. Any other set of hemispheric reamers having the required diameters may be used.

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1 : trial cups (A335XX) 14 : trial inserts (A334XX)

3 : definitive cup impactor with jaws (A36745) 4 : positioning device for definitive cup impactor (A36936)

2 : trial cup handle with 45° orientation rod 45° (A33389) 5 : local impactor for definitive cup (A33428) 6 : local impactor handle (A33601) 7 : impaction ball for definitive cup (A33651) 15 : insert reduction tip (A33398) 16 : handle (A33429) 17 : press for head/insert impaction (A33384) 18 : definitive insert extractor (A33418)

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Base instrumentation top tray A33478

Base instrumentation bottom tray A33478

Impaction cup instrumentation tray A37023 This tray can be replaced by another tray A35940 (impaction system with plastic expansive tips)

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8 : drill (A33565) 9 : flexible (A33560) 10 : drill guide (A33553) 11 : screw depth gauge (A34453) 12 : rack screw (A36295) 13 : 3.5mm hex. screwdriver (A33542)

Screw instrumentation A34234 (for Tregor + only)

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Any surgical approach may be used 1- Planning Using the templates of the range (1.15 scale or any other scale requested), measure the diameter of the cup to be implanted. Calculate the length of the femoral neck based on the medialized center of the joint as shown on the template.

2 - Reaming and trial cup Use reamers of increasing odd or even diameters until a hemispheric cavity in the subchondral bleeding bone or the spongy bone has been obtained. Screw the trial cup (1) having the same size as the last reamer (if even reamers used), or 1mm above the last reamer (if odd reamers used), onto the handle with the 45° orientation rod (2). Impact the trial cup and verify its congruence with the bone. The laser line on the edge of the trial cup provides a visual marker of the boundary of the outer surface of the definitive cup defining a volume that is smaller than the hemisphere (160°). If the trial cup is stable, implant the cup having the same diameter. 3 - Installing the definitive cup Using the impactor with jaws (3), grasp the definitive cup along the circumferential groove etched into its uncoated metal overhang, and turn the lever. After ensuring that the jaws are properly in place, lock the jaws tightly using the thumbscrew. Mount the positioning device (4) at the joints below the grip handle. Forcibly impact the cup into the acetabulum in the typical position of a hemispherical acetabular cup, that is, 45° to 50° forward tilt (45° if the top bar of the positioner is vertical) and 10° to 20° of anteversion (20° of anteversion if the left or right lateral bar, depending on the side worked on, is perpendicular to the longitudinal axis of the lower limb). It is advisable to perform the impaction in a single turn in order to preserve the retentive properties of the acetabular periphery which contribute to the stability of the cup (which is slightly smaller than the hemisphere). Undo the impactor by unscrewing the screw and turning the lever. If resistance is met when removing the jaws from the sides of the cup, check that the opening of either jaw is not blocked by bone residue or soft tissue. Check that the cup is positioned correctly. Should repositioning be necessary, use the local impactor with the screwed-on handle (5,6), and push on the edge of the cup. Complete the impaction on the bottom of the cup using the impaction ball (7). The coated side of the cup should not be visible; generally it should be buried 2 mm behind the equatorial plane. 4 - Placing screws for the TREGOR® + cup (optional) The stability of the TREGOR® cup + may be increased, if needed, by means of 3 screws in the roof of the acetabulum. Prepare the screw holes using the drill (8) mounted on the flexible (9) and guided by the drill guide (10). Using the drill guide with a spherical tip, insert the drill bit along an axis that is slightly ascendant in relation to the edge of the cup so that the screws are as parallel as possible to the lines along which force will be applied (approximately at 15º of the tangent to the cup). Measure the length of screws to be used, using the screw depth gauge (11). Take the screws of the required length in the screw rack (12). Screw the screws in place using the hex. screwdriver (13), without forcing towards the end to prevent the screw head abutting against the hard edge of the bony roof, which could cause a slight movement of the cup.

OPERATIVE TECHNIQUE TREGOR STD / 3 BLADES / + DOC2581

5 - Trial reduction Choose the non-retentive trial insert (14) marked with the diameter of the implanted cup, and a trial head having a diameter of 22 mm or 28 mm. The inserts for the 28 mm diameter head are available for diameter 52 and larger. For the 52 and 54 diameter cups, the polyethylene thickness is 6 mm and 7 mm respectively (the minimum thickness required by the NF EN 12563 standard is 5 mm) for a 28 mm diameter head. The use of inserts which are thinner than 8 mm should be extremely limited; therefore, it's recommended to use a 22 mm diameter head with the 52 and 54 diameter cups. Avoid using a mobile insert with femoral heads which leave part of the cervical morse taper exposed under the head, which will contribute to premature wear of the retentive rim of the definitive insert; in other words, avoid using the 22 long neck and extra-long neck heads and the 28 extra-long neck heads with an Aston femoral piece. Place the insert and the trial head on the femoral stem and reduce the combined set into the cup using the impactor with the conical-shaped insert reduction tip screwed onto its handle (15,16). 6 - Implanting the definitive retentive insert, and reduction On the table, assemble the definitive head and the definitive polyethylene insert using the press (17). Check that it is placed correctly by rotating the head in the insert : movement should be completely unhindered. In the case of head/insert reduction needing to be performed on the patient (such as in the case of a revision of a cup without changing the stem having a monoblock head), a special press called a "gun", which can be adapted to any stem neck width, is available on demand. Place the assembled set on the neck of the femoral stem in place. Impact the assembly using the reduction tip and its handle (15,16). Reduce the hip using the same instrument. It is now possible at this stage, or when performing a revision at a later date, to separate the retentive insert from the head using the extractor (18) screwed onto the handle (16). This extraction may be necessary to in order to recover the insert and exchange the head (only) for a long or extra long neck model, for example. This separation can be performed on the patient, or on the table in the case of a fragile femur. In the latter case, remove the head and its impacted insert using a tamp or the conical tip with its handle (15,16). Mount the head and the insert, still joined together, onto a trial stem or a rasp with a trial neck. This step requires two operators : one to firmly hold the body of the trial stem or the rasp, and the other to perform the separation using the insert extractor. Perform the operation gently over a table to avoid the insert or head being tossed. Recover the insert and use a new head for the re-impaction of the implants.

This surgical procedure is provided for informational purposes only, based on that used by the implant designer surgeons. It’s not available for the US market.

Aston Medical – France – Tel 33 (0)4 77 93 00 04 – Fax 33 (0)4 77 74 35 93 Z.I. Montreynaud – 19 rue V. Grignard 42000 Saint-Etienne