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Background. The widespread introduction of computer planning and 3D printing technologies has opened a new era in the reconstruction of pelvic defects, which allows to ensure maximum anatomical compliance, especially in defects in several segments of the pelvis. Optimization of the implant fit to the bone edges reduces the risk of instability and overloads at the contact points, which improves the long-term stability of the structure. The purpose was to determine the features of stress distribution in human pelvis models with endoprostheses of different designs after resection of the hip socket due to oncological diseases. Materials and methods. A basic finite element model of the human pelvic girdle with femurs was developed, on which 3 options for arthroplasty of the left hip joint were created in conditions of a post-resection segmental defect of the pelvic bones, which violates the integrity of the anterior pelvic ring: 1 — replacement using an endoprosthesis without replacing the defect; 2 — arthroplasty using an endoprosthesis with restoration of the integrity of the pelvic ring; 3 — a model without defects of the pelvic bones with a standard hip joint replacement. The models were loaded with a vertical distributed force of 540 N. The action of m.gluteus medius was simulated with a force of 1150 N and m.gluteus minimus had rigid fixation. Results. When using an endoprosthesis of the hip socket without restoring the integrity of the pelvic ring, the maximum stress level was determined in the superior iliac spine and did not exceed 21.6 MPa. The most stressed element of this type of endoprosthesis is the screws in the iliac flange — 182.3 MPa. At the same time, the stress in the iliac flange itself was observed at a rather low level of 29.0 MPa. The reason for this stress distribution is the cantilevered version of the cup attachment. When using an endoprosthesis that restores the integrity of the pelvic ring, a significant increase in the stress level was observed: in the lesser sciatic notch under the iliac flange of the endoprosthesis — to 79.6 MPa and to 69.0 MPa in the greater sciatic notch. The stress level in the right (intact) pubic bone increased almost 8 times — 33.5 MPa, which is a consequence of the fact that it is the second fixation point of the endoprosthesis. The maximum stress level was determined for the screws in the contralateral pubic bone — 113.4 MPa. But due to the presence of the second attachment point (on the pubic bone), the stresses in the iliac flange screws do not exceed 86.8 MPa. Conclusions. The use of the endoprosthesis without restoring the integrity of the pelvic ring leads to a significant decrease in stresses in the bone elements on the prosthetic side, although it is accompanied by an increase in stresses on the iliac flange screws. Arthroplasty with restoration of the pelvic ring causes a significant increase in stresses in the prosthesis fixation zones, especially in the area of the intact pubic bone, which becomes the second supporting link of the structure. An increase in stresses in the elements of the endoprosthesis and the bone model is associated with the high rigidity and mass of titanium components. According to the criteria of minimizing stresses in the bones and in the endoprosthesis, the option without restoration of the pelvic ring is more favorable.