A total of 221 patients were treated conservatively for acute knee ligament injuries at the Tampere University Central Hospital in Finland between 1975 and 1981. Ninety-eight patients had an acute tear of the anterior cruciate ligament (ACL), alone (37) or in combination with the medial collateral ligament (MCL) (61). Ninety-six had an isolated MCL injury, and 27 had an isolated injury of the lateral ligament compartment (LAT) of the knee.
The patients were immobilized in plaster cast, posterior splint, or knee bandage, and no attempts were made to correct ligamentous instability. The patients started isometric exercises of the quadriceps and hamstrings during the first one to two weeks of the immobilization period. Straight leg raises were usually instituted within the first two to four weeks. Walking with crutches with partial weight-bearing was allowed approximately one to two weeks after injury, and full weight-bearing was allowed after two to five weeks. Increasing mobilization and rehabilitation of the injured knee was usually begun immediately after the immobilization period, and the rehabilitation continued under supervision of the attending surgeon for at least six months.
The follow-up study of the patients (average, eight years after the injury; range four to twelve years) included a questionnaire; clinical examination; functional tests; radiological examination; knee strength measurements by a isokinetic testing device; the Lysholm and Marshall scales for subjective, clinical, and functional evaluations; and the authors' scales for radiological and muscle strength evaluations.
The multidimensional follow-up analysis revealed that the long-term outcome after a Grade II sprain (partial tear) of the ACL, MCL, or LAT was good and acceptable even if residual mild or moderate laxity was often demonstrable. In Grade III sprains (complete tears), the long-term results were poor, involving an unstable knee with thigh muscle weakness, post-traumatic osteoarthritis, and severe subjective symptoms.