Sixty patients were treated for medial instability by advancement of the medial collateral ligament and posteromedial capsule as a single cuff, moving its tibial attachments both anteriorly and distally. Using a 0 to 4+ grading scale to quantitate medial instability, all patients had 2+ medial instability or more preoperatively while at follow-up thirty-six had 0, twenty-one, 1+; and three, 2+ in stability. Forty-five improved two grades or more. In only two of these sixty patients was disability not decreased after medial reconstruction. In twenty-six of the sixty knees, absence of the anterior cruciate was established at operation. Medial repair alone decreased anteroposterior instability (according to a five point grading system) one grade in fourteen knees, two grades in five, and three grades in one. No improvement occurred in four.