Comparison between Two Zurich Cementless Total Hip Replacement Cup Impactor Types in the Accuracy of Cup Positioning:...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Surgical Instrumentation

Background:

• Accurate prosthetic cup positioning is crucial for successful total hip replacement (THR) outcomes.
• Surgeon experience and surgical tools can influence the precision of acetabular component placement.
• Variations in cup positioning may lead to complications such as dislocation or loosening.

Purpose of the Study:

• To evaluate the impact of two different cup impactors (standard vs. prototype) on the accuracy of prosthetic cup positioning in THR.
• To compare the performance of these impactors when used by surgeons with varying levels of experience (beginner vs. senior).
• To assess the influence of impactor design and surgeon experience on the angle of lateral opening and cup retroversion.

Main Methods:

• A cadaveric study involving 40 canine acetabula (n=20).
• Eighty prosthetic cups were impacted using a standard and a prototype Kyon impactor by a beginner and a senior surgeon.
• Radiographic imaging was used to measure the angle of lateral opening and cup retroversion, comparing them to ideal postoperative values.

Main Results:

• The senior surgeon's accuracy was unaffected by the impactor type for both measured angles.
• The beginner surgeon achieved significantly better accuracy for the angle of lateral opening with the prototype impactor compared to the standard one.
• No significant difference in cup retroversion accuracy was observed between the impactors, regardless of surgeon experience.

Conclusions:

• The prototype impactor's design and handling may aid less experienced surgeons in achieving optimal lateral opening angles during THR.
• Surgeon experience appears to be a more significant factor than impactor type in achieving accurate cup retroversion.
• Further research into surgical tool design can enhance precision and potentially improve patient outcomes in total hip replacement.