How is patella height modified after total knee arthroplasty?

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Patella height measurement is crucial in knee assessments.
• Existing methods are often unsuitable for post-total knee arthroplasty (TKA) evaluation.
• The modified Caton Deschamps (mCD) index offers a new approach using distinct landmarks.

Purpose of the Study:

• To evaluate how patella height changes after primary total knee arthroplasty (TKA).
• To assess the impact of these changes on functional outcomes.

Main Methods:

• Prospective enrollment of 60 primary TKA patients receiving a specific implant type.
• Recording of patient characteristics, functional, and radiological outcomes pre-operatively and at one-year follow-up.
• Comparison of pre- and post-operative outcomes using paired t-tests and ANOVA for group comparisons.

Main Results:

• An average patella lowering of 0.19 was observed post-TKA using the mCD index.
• Patella height was reduced in 81.7% of cases.
• No significant differences in functional scores (IKS, ROM) were found between groups categorized by patella height lowering.

Conclusions:

• The modified Caton Deschamps (mCD) index effectively measures patella height changes after TKA.
• Moderate patella lowering (under 15%) shows no significant impact on functional results.
• Further research is needed to identify factors influencing patella lowering and explore preventive strategies.