A
Release the posterior cruciate ligament
B
Resect more distal femur
C
Externally rotate the femoral component
D
Release the medial collateral ligament
Explanation:The correct option is 'c'. In gap balancing, if the flexion gap is tight medially (varus in flexion) while the extension gap is balanced, externally rotating the femoral component will open the medial flexion space without altering the extension gap. Releasing the MCL would destabilize the already balanced extension gap.
Reference: Dennis DA, et al. Gap balancing versus measured resection technique for total knee arthroplasty. Clin Orthop Relat Res. 2010;468(1):102-107.