Two hundred and forty-five knee dislocations were analyzed including forty-one new cases. The high incidence of injuries to the popliteal artery that accompanies this lesion (32 per cent) was confirmed, and it was re-emphasized that vascular repair must be completed within six or at the most eight hours from the time of injury to avoid amputation. Of the patients not treated within that time period, 86 per cent had an amputation and two-thirds of the remaining 14 per cent had ischemic changes.