Component size asymmetry in bilateral total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Bilateral total knee arthroplasty (TKA) is a common procedure for treating severe knee osteoarthritis.
• Standard surgical practice involves selecting component sizes independently for each knee.
• Potential variations in component sizing between contralateral knees warrant investigation.

Purpose of the Study:

• To investigate the incidence of component size asymmetry in patients undergoing bilateral total knee arthroplasty (TKA).
• To determine if femoral, tibial, or patellar component size asymmetry affects postoperative knee function and outcomes.

Main Methods:

• Retrospective review of 268 consecutive patients who underwent bilateral TKA.
• Analysis of preoperative radiographic templating and intraoperative sizing measurements.
• Comparison of component sizes (femur, tibia, patella) between right and left knees.
• Evaluation of knee function, pain, range of motion, and complications.

Main Results:

• Femoral component size asymmetry was observed in 18 (6.7%) of the 268 bilateral TKAs.
• No statistically significant differences were found in patellar or tibial component size asymmetry between knees.
• Patients with asymmetrical femoral components showed no significant differences in knee score, pain, function, range of motion, lateral release incidence, or complications.

Conclusions:

• A small percentage of patients undergoing bilateral TKA may receive asymmetrically sized femoral components.
• Femoral component size asymmetry in bilateral TKA does not appear to negatively influence short-term functional outcomes or complication rates.
• Current sizing methods for bilateral TKA seem adequate, as asymmetry did not correlate with poorer results.