The aim of the study was to determine the cause of the high frequency of meniscal tear coexisting rupture of the anterior cruciate ligament of the knee joint and to establish an optimal timing of surgical stabilization of the knee joint. Medical records of 476 patients who had surgery at the clinic of the Kirov Military Traumatology and Orthopedics of Military Medical Academy were studied. In 82 patients operation on the reconstruction of the anterior cruciate ligament was perormed in the early period after injury (up to 6 weeks), 347 patients were operated within a period exceeding 6 weeks. It was revealed that the soldiers who had the operation in the period after 6 weeks from the date of injury, secondary damage of meniscus and articular cartilage occured twice as much as in surgery performed during the acute phase. Thus, the reconstruction of the anterior cruciate ligament should be carried out in a specialized epartment in the early stages after injury, when not yet any secondary damage to the meniscus and articular cartilage.