Femoral Component Axial Rotation in the Gap-Balancing Approach to Total Knee Arthroplasty: Measurement by Computed Tomography

Mean FC rotation values as evaluated by PCA were −2.26° and −2.56° and as evaluated by CTA were −5.54° and −6.28°. PCA and CTA measurement by CT is reliable; however, the use of PCA is preferable because of the higher observer concordance. PCA can be inferred by subtracting 3° or 4° from the CTA. MES was identified in 64% and 78% of patients, with only moderate interobserver agreement.