The authors retrospectively reviewed RNIITO Arthroplasty Registry data of revision total hip arthroplasties performed in RNIITO in 3 year period (2011-2013). Part of early revisions within 5 years after the index procedure in general revision structure was 33% . Two hundred seventy three (64%) procedures had infection reason, 79 (19%) - aseptic loosening, 35 (8%) - dislocation and 27 (6%) - periprosthetic fractures in reasons of revision, respectively. More than half of revisions were performed within the first year after the index procedure. Early primary revisions after index total hip arthroplasty were performed in 254 (59,8%)cases, and repeated revisions were performed in 171cases one or more times. Of early primary revisions 125(49,2%) patients had index total hip athroplasty in our hospital, and 129 (50,8%) patients had index total hip athroplasty in other hospitals of Russian Federation. Our THA early revision structure is differs significantly from published in literature, moreover there is difference between revision reasons after primary total hip arthroplasty of our hospital and other hospitals. Revision reasons structure doesn’t show rate of primary THA complications, but defines main problems that should be solved.

т р а в м а т о л о г и я и о р т о п е д и я р о с с и и 2014-1 (71)

A technology to create a cell-seeded fibrin-based implant matching the size and shape of bone defect is required to create an anatomical implant. The aim of the study was to develop a technology of cell-seeded fibrin gel implant creation that has the same shape and size as the bone defect at the site of implantation. Using computed tomography (CT) images, molds representing bone defects were created by 3D printing. The form was filled with fibrin glue and human dental pulp stem cells (DPSC). The viability, set of surface markers and osteogenic differentiation of DPSC grown in fibrin gel along with the clot retraction time were evaluated. In mice, an alveolar bone defect was created. The defect was filled with fibrin gel seeded with mouse DPSC. After 28 days, the bone repair was analyzed with cone beam CT and by histological examination. The proliferation rate, set of surface antigens and osteogenic potential of cells grown inside the scaffold and in 2D conditions did not differ. In mice, both cell-free and mouse DPSC-seeded implants increased the bone tissue volume and vascularization. In mice with cell-seeded gel implants, the bone remodeling process was more prominent than in animals with a cell-free implant. The technology of 3D-printed forms for molding implants can be used to prepare implants using components that are not suitable for 3D printing.

This work examines a biomechanical system consisting of the hip endoprosthesis and bones of the pelvic region of a person under a load corresponding to the equilibrium of a person in double-supported state. An assessment of the strength of a customised endoprosthesis has been carried out based on the analysis of the stress-strain state of the finite element model of the "skeleton-hip prosthesis" system when tightening the screws and when the system is subjected the person's weight; dangerous areas of the pelvic bone with high level of stresses have been identified. As recommendations, optimization of the location and number of screws used in order to create a more uniform stress distribution is proposed.

Purposes are to determine1) what frequency and what degree is of custom acetabular implants malposition in comparison with planned position, 2) what the reason of malposition is and 3) what the malposition consequences we can wait for.Patients and methods. The observation group included 20 patients (18 women and 2 men) with severe ac-etabular defects. Mean age of patients made up 53 (22-72) years. Position of the implants was compared with the parameters of preoperative planning using 5 postoperative CT indices (inclination, anteversion of semi-spherical part of the implant, spatial location of the rotation center in three axes). More than 10° deviation for inclination or anteversion and 5° dislocation of the rotation center in any axis was considered as a malposition of the component.Results. Only 5 of 20 constructions matched conditionally permissible limits by all the parameters. Most often excessive dislocation of the rotation center in lateral direction (10 cases) and excessive anteversion (9 cases) were observed. During 6 weeks follow up no complications related to the acetabular component position were recorded.Conclusion. It was shown that at revision arthroplasty with custom-made implants the probability of implant malposition as compared to the preoperative plan. The main reason could be the complexity of intraoperative orientation under conditions of abnormal hip anatomy. Malposition of the implants beyond the stated values did not result in complications within the early postoperative period. The longer follow up is required for the assessment of the long-term results.

No abstract

Revision hip arthroplasty rate is growing, and pelvic discontinuity rate ranges from 1% to 5% of acetabular component revision reasons. According to AAOS acetabular defects classification, pelvic discontinuity is fourth type defect in which cranial part of hip bone is separated from caudal part at acetabular level. Usually it occurs from bone loss secondary to osteolysis, infection, fracture or aseptic loosening. There are a lot of techniques for pelvis discontinuity treatment. Published results of bulk allografts and antiprotrusion cages have generally been poor. More preferable methods with acceptable rate of good results are cup-cage systems and custom triflange acetabular components(CTAC). CTACs are designed based on preoperative CT scans to build a custom titanium 3D-printed implant to address the patient's specific bone defect and provide secure fixation in the ilium, pubis, and ischium. We faced pelvic discontinuity, in which extensive iliac bone loss was added to caudal hip bone part medial displacement and pelvic ring deformity, in patient with multiple hip surgeries. Preoperative investigation called into question the possibility of using off-the-shelf hip implants, which could restore the biomechanics of the hip and provide reliable primary fixation at the same time. We present case report of the patient with pelvic discontinuity and massive bone loss treatment using a custom triflange component.

The aim of this study was the assessment of early outcomes of patient-specific three-dimensional titanium cones with specified porosity parameters to compensate for extensive metaphysical-diaphyseal bone defects in RTKA.Materials and Methods. Since 2017 till 2019 30 patient-specific titanium cones (12 femoral and 18 tibial) implanted during 26 RTKAS. Clinical outcomes evaluated using KSS, WOMAC and fjS-12 scoring systems on average 10 (2–18) months after surgery. At the same time the stability of implant fixation analyzed using frontal, lateral and axial knee roentgenograms.Results. During all procedures there were no technical difficulties in positioning and implantation of custom-made titanium cones. At the time of preparation of the publication, none of the patients had indications for further surgical intervention, as well as intra- and postoperative complications. Six months after surgery all scores improved significantly: KSS from 23 (2–42, SD 19.96) to 66.5 (62–78, SD 7.68), WOMAC from 59 (56–96, SD 28.31) to 32.25 (19–46, SD 11.76), the index FJS-12 was 29.16 points (0–68.75, SD 30.19). The average scores continued to improve up to 18 months: KSS — 97.5 (88–108, SD 9.14), WOMAC — 16.5 (9–24, SD 6.45), FJS-12 — 45.85 (25–75, SD 22.03). No radiolucent lines were noticed during this period of observation.Conclusion. The original additive technology of designing and producing patient-specific titanium cones for compensation of extensive metaphyseal-diaphyseal bone defects in RTKA is a valid solution at least in the short term. A longer follow-up period is required to assess its medium-and long-term reliability compared to existing alternative surgical solutions.