Positioning System surgical technique

The orientation of the acetabular cup is one of the most important factors under the surgeon's control2, and acetabular cup orientation has a significant effect on device performance, including patient outcomes, impingement, edge loading, bearing wear, osteolysis and loosening3,4. Clinical issue Safe zones There have been various attempts to define a ‘safe zone’ for the orientation of an acetabular cup, and increasing evidence to suggest that one generic zone is not applicable5,6,7,8,9. There remains two key issues with THR today: 2 Are we able to achieve that orientation? 1 What is the target...

2 Delivery Clinical issue Intra-operative tools It is inherently difficult to position the cup during surgery and achieving a target position is a considerable challenge in THR. It has been shown that up to 50% of surgeries miss the intended orientation11 and the chance of hitting a target to within 5° can be as low as 21.5%12. Clinical solution How is the optimised position delivered during surgery? Once the target orientation for a specific patient has been decided, a unique guide is produced for the individual. The planned orientation is built into the axis of the guide which is used intra-operatively...

tpq™ Optimized Positioning System Optimizing your practice The Corin OPS™ is a state-of-the-art pre-operative planning technology and delivery system, designed to enable you to deliver on an optimised acetabular cup position for each of your patients. Dynamic simulation Personalized solution

Functional safe zone Every patient moves differently, and the amount of pelvic tilt through functional activities should be accounted for with total hip replacement1. OPS™ is designed to optimally orientate a cup within a safe zone, and for the cup to remain within that safe zone as the pelvis rotates throughout functional activity. Safe zone Responsible Innovation

1. Laser canister assembly 2. Pelvic construct preparation 3. Assessment of guide and model The laser is inserted into the lower housing and the cap is screwed on securely. The laser should now be permanently on, and the laser dot should be visible across the theatre with the naked eye. Assemble the pelvic screw onto the T-handle inserter and place either around the acetabulum within the incision or percutaneously in the iliac crest. Ensure the screw is rigidly fixed into bone. Screw the bolt into the guide and tighten with the hex handle driver, then place the guide into the acetabular model....

Remove the fat pad and remnants of the ligamentum teres from the acetabular fossa. Ensure the thin layer of cartilage is removed from the fossa lip. Identify where the arms of the guide will sit within the acetabulum and ensure all cartilage has been removed from these areas. Place the guide assembly into the acetabulum using the guide holding forceps and apply a superomedial pressure to ensure it is rigidly stable. Attach a laser to the end of the curved guide handle. Holding the guide firmly in place with the forceps, slide the curved guide handle over the guide assembly. Note: Ensure the guide...

7. Laser alignment Attach a laser canister onto the adjustable clamp. Lower the assembly onto the pelvic post and secure with dial. Lower the assembly onto the pelvic screw. 8. Acetabular reaming Adjust the alignment of the pelvic laser to converge with the acetabular guide laser as projected on the ceiling or wall and secure with dial. Note: Ensure that the pelvic laser setting is not accidentally altered between alignment and cup impaction. Ream the acetabulum as per the routine technique. Note: It is recommended to remove pelvic laser assembly from pelvic screw during reaming.

9. Identification of target orientation After reaming place the pelvic laser assembly back onto the pelvic screw. The position of the pelvic laser on the ceiling or wall may have moved as a consequence of the pelvis moving on the table during reaming and retraction. Screw a laser canister into the magnetic impactor adaptor and attach to the end of the cup introducer. Place the cup in the acetabulum and adjust the orientation until the laser converges with the pelvic laser on the ceiling or wall. Remove the laser adaptor from the end of the inserter and impact. The laser adaptor can be repeatedly...

Compatibility guide ™ compatible with BIOLOX® delta and ECiMa™ only Taper size Trinity™ shell outer diameter Polyethylene liner Ceramic liner Polyethylene liner (UHMWPE, HXLPE and ECiMa™)

The Corin Optimized Positioning System™ consists of a software component and hardware components. The software component assists the surgeon in determining a target orientation for the acetabular cup through a functional, dynamic and patient specific simulation. The hardware components consist of a patient specific guide, bone model and reusable instrumentation to deliver the target orientation. The system is designed to assist the surgeon in total hip arthroplasty, and is appropriate for all surgical approaches. The Corin Optimized Positioning System™ is intended to be used as a patient specific...

References: 1. DiGioia AM, Hafez MA, Jaramaz B, Levison TJ, Moody JE, Functional pelvic orientation measured from lateral standing and sitting radiographs. Clin Orthop Relat Res 453:272–276 8. Pedersen DR, Callaghan JJ, Brown TD. Activity-dependence of the “safe zone” for impingement versus dislocation avoidance. Med Eng Phys 2005; 27:323 2. Echeverri S, Leyvraz P, Zambelli P, et al. Reliable acetabular cup orientation with a new gravity-assisted guidance system. J Arthroplasty 2006; 21(3):413 9. Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after total hip-replacement...