Collateral ligament laxity has recently been recognized as an important component of frontal plane malalignment. The authors have developed new surgical techniques to re-tension lax collateral ligaments. Twenty-three collateral ligament re-tensioning with bony alignment were carried out in 17 patients, with 19 knees being graded excellent, 2 fair, and 2 poor. Recurrence of significant laxity was noted in one patient.