Aim. To assess complex radiodiagnosis and highly specialized medical care as knee joint replacement (KJR) to patients with hemophilic arthropathies (HA) who live in the Republic of Kazakhstan. Subjects and methods. The results of examination and treatment were analyzed in 40 patients with knee HA who were treated at the specialized Polytrauma Unit, Republican Research Center for Emergency Health Care. All patients with hemophilia A underwent joint X-ray study, computed tomography and magnetic resonance imaging (MRI), X-ray densitometry and ultrasound osteometry on admission and after KJR. Results. Joint X-ray studies and computed tomography revealed that all the patients had Grades II-III arthroses with severe dysfunction of joints, their multiple involvements of different grades, which depended on the rate of recurrent hemarthrosis. Ultrasound study (USS) is the only mini-invasive method to control surgical hemostasis in hemophiliac patients after KJR. Osteodensitometry revealed osteopenia and osteoporosis in all the patients with hemophilia, which was a basis for prescribing calcium preparations in the early postoperative period for the prevention of instability of endoprosthetic components. We elaborated an algorithm for combination treatment in HA patients, which involved knee joint replacement. Conclusion. Highly specialized medical care to hemophilic patients and active introduction of the early surgical rehabilitation of the affected joint in their combination treatment contributed to the increased number of positive results, by restoring the quality of life in the patients: excellent, good, and satisfactory anatomic and functional results were obtained in 26.7, 51.1, and 22.2%, respectively. USS and MRI could evaluate joint changes in HA in detail, which plays an important role in the estimation of the course time of the disease, in the planning of endoprosthetic replacement, and in the timely prevention of severe complications of HA. Osteodensitometry makes it possible to monitor bone mineral density around the prosthesis and to postoperatively prevent endoprosthetic instability.