The late course of acute partial anterior cruciate ligament tears. A nine to 15-year follow-up evaluation.

Twenty-two patients had an acute anterior cruciate ligament (ACL) tear. Nineteen patients were treated conservatively, except for associated injuries. In three patients, a reinsertion of the torn portion of the ACL was done surgically. All patients were reexamined after nine to 15 years with special emphasis on stability testing; this was done manually and with instruments. Knee function score and activity level were also measured. Standing roentgenograms with the knee in slight flexion were taken as well. At follow-up examination, none of the patients had needed ACL reconstruction. Knee function was good, with a mean Lysholm score of 93 points. Patients had changed activities from recreational team sports to light individual sports. Manual laxity values were similar to the values obtained at the time of initial injury. A 1-mm sagittal laxity increase was found on the injured knee with the Stryker laxity tester. Slight signs for osteoarthrosis were found in more than half of the knees, mainly in cases with chondral fractures or meniscectomy. In general, conservative treatment had a good long-term prognosis.