Preoperative gait patterns and BMI are associated with tibial component migration

Area of Science:

• Orthopedic surgery
• Biomechanics
• Biomedical engineering

Background:

• Standardized patient triage for total knee arthroplasty (TKA) is lacking.
• Objective measures for TKA success (function, longevity) are underdeveloped.
• Preoperative metrics influencing TKA outcomes require further investigation.

Purpose of the Study:

• To investigate the association between the preoperative mechanical joint environment during gait and post-TKA tibial component stability.
• To assess the utility of radiostereometric analysis (RSA) in measuring TKA outcomes.
• To identify preoperative functional characteristics that predict TKA success.

Main Methods:

• 37 subjects from a randomized RSA trial underwent 3D gait analysis preoperatively.
• Radiostereometric analysis (RSA) was used for longitudinal measurement of tibial component migration.
• Data were collected at 6 months and 1 year postoperatively.

Main Results:

• A significant association was found between preoperative knee adduction moment during gait and implant migration at 6 months.
• Implant type, preoperative joint loading, and BMI explained 45% of tibial component migration variability at 6 months.
• These associations were not statistically significant at the 1-year follow-up.

Conclusions:

• Preoperative patient functional characteristics, especially joint loading patterns, are crucial for TKA outcomes.
• This study is a foundational step towards predictive models for objective TKA outcomes.
• Findings may inform improved patient selection and treatment strategies for total knee arthroplasty.