Although component malrotation in total knee arthroplasty may result in a decreased level of improvement from pain, published results showed it did not significantly affect function or quality of life at midterm follow-up.
To determine the effect of femoral, tibial and combined component rotation in primary TKA, researchers measured function with the Knee Society Score, pain and quality of life with the SF-12 score and prosthesis failure. Researchers defined malrotation as being internally rotated from neutral, the femoral component externally rotated greater than 5° and the tibial component internally rotated greater than 6° or the two components combined internally rotated from neutral.
At 5 years postoperatively, results showed component rotation had no clinically relevant correlation between function or quality of life. However, researchers found less improvement in overall pain scores among patients with combined component malrotation vs. patients who were not malrotated.
“We found it difficult to prove our hypothesis that malrotation of the components, being femoral, tibial or a combination, resulted in poorer clinical outcomes in the medium term,” the authors wrote. “Improvement in pain is reduced with malrotated components, but the overall function and pain levels at 5 years are similar in both groups. Correct component rotation is difficult to define in TKA and its effects on patient-reported outcome are unlikely to be easily predicted.” – by Casey Tingle
Disclosures: Babazadeh reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.