This article presents a clinical case of combined injury of three ligaments (anterior and posterior cruciate and medial lateral ligaments) in a 46-year-old overweight woman (BMI = 38). The late diagnosed damage to the ligaments and the lack of conditions for their normal recovery led to combined instability of the knee joint and the appearance of indications for their reconstruction. At the moment, 6 weeks after the operation, the patient began to step independently on the operated limb, the range of permissible movements in the knee joint was flexion up to 90 degrees. The planned period of full recovery is 24 weeks. Key words: combined knee joint instability, posterior cruciate ligament, medial lateral ligament, anterior cruciate ligament, knee injury, clinical case.