Are younger patients undergoing TKAs appropriately characterized as active?

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Rehabilitation Science

Background:

• Increasing use of total knee arthroplasty (TKA) in younger patient populations.
• Demographic and activity level variations in young TKA recipients may influence implant outcomes.
• Current practice often presumes higher activity in younger patients based on age and diagnosis.

Purpose of the Study:

• To investigate if demographic features of young TKA patients predict high post-operative activity.
• To determine if pre-operative or post-operative functional activity measures support the projection of high activity in young TKA recipients.

Main Methods:

• Retrospective comparison of 150 patients ≤55 years old with 262 patients aged 65-75 undergoing TKA.
• Analysis of demographic data (gender, BMI, diagnosis) and functional activity using UCLA, Knee Society, and WOMAC scores.
• Comparison of pre-operative and post-operative functional activity profiles between younger and older TKA cohorts.

Main Results:

• Younger TKA patients were more likely female (74% vs. 60%) and had non-osteoarthritis diagnoses (18% vs. 3%).
• Younger female patients had higher BMIs (35 kg/m² vs. 31 kg/m²).
• Male patients exhibited higher post-operative activity scores (UCLA, Knee Society, WOMAC) than females, but differences were not significant between younger and older cohorts.

Conclusions:

• Age and diagnosis alone are unlikely to be primary drivers of revision TKA in younger patients due to high activity.
• Measured functional activity, rather than age or diagnosis surrogates, is crucial for evaluating TKA survivorship and prosthetic performance.
• Future research should focus on objective activity metrics to understand TKA longevity in diverse patient groups.