CORAIL® PINNACLE®

PINNACLE Shell Surgical Technique

These key surgical steps are highlights only and may not be used for training purposes. For the detailed procedure, please refer to the PINNACLE Surgical Technique Brochure (9068-80-050)

Templating and Pre–Operative Planning

The radiographs should clearly demonstrate the acetabular configuration and the endosteal and periosteal contours of the femoral head, neck and proximal femur

Using the A/P radiograph, position the template 40° – 45° to the inter–teardrop or interischial line so that the inferomedial aspect of the cup abuts the teardrop and the superior–lateral cup is not excessively uncovered

Acetabular Reaming

The goal of acetabular reaming is to restore the centre of the original acetabulum. Initially employ a reamer 6 – 8 mm smaller than the anticipated acetabular component size to deepen the acetabulum to the level determined by pre–operative templating. Subsequent reaming should proceed in 1 – 2 mm increments. Centre the reamers in the acetabulum until the deepened socket becomes a true hemisphere. Use a curette to free all cysts of fibrous tissue. Pack any defects densely with cancellous bone.

Tip: It is important to understand that all PINNACLE Hip Solutions Instrumentation is marked with true dimensions. The reamers, trial cups and actual PINNACLE Acetabular Cups are all 180°. Under–reaming of the acetabulum is dependent on bone quality and the size of the acetabular component. A 1 mm under–ream is usually sufficient in smaller sockets, while a larger socket may require 1 – 2 mm under–ream. Likewise, soft bone will more readily accommodate a greater press–fit of the acetabular component than sclerotic bone. In some patients, line-to-line reaming may be sufficient to achieve stability.

A 54 mm QUICKSET™ grater reams a 54 mm cavity

A 54 mm trial cup os 54 mm in diameter

A 54 mm PINNACLE Acetabular Cup is 54 mm in diameter as measured over the POROCOAT® Porous Coating

Acetabular Cup Trialling and Positioning

Trial cups in 1 mm incremental sizes are available to assess cup fit and orientation. Contingent on the quality of the prepared bone, select the acetabular trial equal to or 1 mm larger in diameter than the final reamer size. The size of the trial cup is as marked on the trial cup (54 mm measures 54 mm). Peripheral rim ridges on the trial cup enhance the stability of the trial cup through trial reduction. Even liner trials fit both even and smaller odd trial cups. For example, a 54 mm polyethylene liner trial fits both the 54 mm and the 53 mm trial cups. Using cup and liner trials in conjunction with the femoral component trials aids in ensuring optimum position of the components.

Cup Positioning

Peer reviewed publications highlight the importance of acetabular component positioning in relation to short and long term outcomes during total hip arthroplasty for all types of bearing materials.1-8

Cup positioning should be varied to optimise fixation, range of motion and dislocation resistance and minimise the likelihood of subluxation, impingement and edge loading. This may be assessed during pre-operative planning, acetabular preparation and cup trialling. Sub-optimal component positioning may lead to edge loading, dislocation, increased wear, elevated metal ion release, ceramic squeaking and polyethylene fracture.1-8

The target cup inclination (as measured on radiographs) should be 40-45° taking into account local soft tissue and anatomic landmarks. The target cup anteversion (as measured on radiographs) should be 15-20° taking into account local soft tissue and anatomic landmarks.

An alignment guide is provided to assist with cup positioning; however, cup orientation in the patient depends on patient position. The alignment guide does not allow for variation in patient position with respect to the operating table and it should be noted that patient orientation can vary throughout the procedure.

Cup Position and Orientation Using the TAL

PINNACLE Alignment Guide System

The PINNACLE alignment guide system may be used to indicate an acceptable level of acetabular inclination and version. Once assembled, the inserter handle should be raised until the vertical bar is perpendicular to the plane of the operating table. With the patient in the lateral decubitus position and the version guide parallel to the floor.

The inserter handle should then be rotated until the horizontal bar is in line with the patient's longitudinal axis.

The extended arm of the version guide follows the long axis of the patient’s body, corresponding to the affected hip, to achieve appropriate anteversion.

Implanting a PINNACLE 100 Primary Acetabular Cup

Before implanting the final prosthesis, take the hip through a full range of motion and stability assessment with all trial components in position. Securely thread the permanent acetabular cup prosthesis onto the acetabular cup positioner. Use the PINNACLE external alignment guide to assist in component orientation.

After confirming alignment, impact the prosthesis into position. Given the nature of a hemispherical acetabular component, rim contact will occur before dome seating occurs. This may require additional impactionto ensure seating. Confirm seating by sighting through the apical hole or, if present, screw holes. An apical hole eliminator may be inserted with a standard hex head screwdriver following cup impaction.

Please continue to either the Polyethylene or Alternative Bearing Inserts key steps

Implanting a PINNACLE Sector Acetabular Cup with Screw Fixation

The PINNACLE Sector Cup has three screw holes and is designed for insertion with screws. Two medial hole alternatives are placed to enable screw placement up the posterior column in either the right or left hip. The single lateral screw provides additional access to the ilium.

The screw angle may vary by as much as 34˚.

Select holes where the prosthesis is to be anchored with cancellous screws so that the screws lie within a safe quadrant. The safe quadrant is defined by two lines from the anterior–inferior iliac spine through the centre of the acetabulum and posterior by a line from the sciatic notch to the centre of the acetabulum.

Please continue to either the Polyethylene or Alternative Bearing Inserts key steps

Implanting a PINNACLE 300 Acetabular Cup with Spikes

Spikes are placed along the radius of the PINNACLE 300 Series cup are coated and are for additional fixation. The spike height in the 300 Series cup ensures that the spike contacts bone on insertion at the same point that the cup contacts the rim of the prepared acetabulum. This gives the surgeon greater control when inserting the 300 Series cup and ensures the cup bottoms out in the dome of the acetabulum.

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