Background: The supercapsular percutaneously-assisted total hip (SuperPATH) approach is a muscle sparing surgical technique for total hip arthroplasty (THA). The literature reports good clinical and functional results of the SuperPATH technique in the short term. We aimed to compare early outcomes and gait analysis of THA using the mini posterior approach (MPA) and supercapsular percutaneously-assisted total hip (SuperPATH) approach. Methods: 44 patients who underwent THA, were randomly allocated to either MPA or SuperPATH. The data were then collected prospectively (preoperatively and postoperatively at 6 weeks). Plain anteroposterior radiographs of the pelvis and instrumental gait analysis were obtained. The visual analogue scale (VAS), Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Scores (HOOS) were used to assess functional and clinical outcomes. Results: No significant difference was found in patients’ surgical outcomes. Patients in the SuperPATH group had less pain according to the VAS score at follow-up than the MPA group ( p < 0.01). There was also a significant improvement in HHS and HOOS scores for all patients ( p < 0.001) with the SuperPATH group showing superior changes. The comparison of mean differences in gait velocity between preoperative and 6 weeks postoperative result, revealed improvement in the SuperPATH group over the MPA group ( p = 0.06). Limping was more persistent in the MPA group. Kinematic parameters demonstrated improved hip joint excursion slightly higher in the MPA group. There was no significant improvement in kinetic and kinematic parameters at different walking moments for all patients at 6 weeks compared to preoperative gait patterns. Conclusions: SuperPATH and MPA both show excellent results. This study reveals that the SuperPATH technique was associated with lower postoperative pain levels, and higher physical function and quality of life. Improved functional outcomes allowed earlier postoperative rehabilitation and faster recovery. Specific improvement in gait patterns were identified with nonsignificant differences between the 2 approaches at 6 weeks follow-up.

Employment of custom triflange acetabular components (CTAC) is one of the few options for pelvic reconstruction in the patients requiring complex acetabulum revisions with Paprosky 2 C, 3 A and 3 B defects and pelvic ring disruption.The purpose of the study was to describe the features of planning, surgical technique, and short-term treatment outcomes of the patients with significant acetabular defects, in which the revision hip arthroplasty was performed using the CTAC.Materials and Methods. A single-center analysis of a series of consecutive patients was performed: 50 complex acetabulum revisions in 47 patients (16 men and 31 women). The average age of the patients was 60±12 years (from 31 to 82; Me 62 years), the average body mass index was 29.7±6.3 kg/m2 (18.4 to 46.3; Me 29.0 kg/m).Results. The mean follow-up was 22±13 months (from 3 to 3.6 years; Me 20 months). The average Harris score increased from 27±7 (from 15 to 39; Me 27) before surgery to 64±16 (from 22 to 90; Me 67) a year after (p<0.001). The level of pain according to VAS before surgery was 7±1 points (from 5 to 9; Me 7), after treatment it decreased to 2±1 points (from 0 to 7; Me 1, p<0.001). In 17 cases out of 50 (34%), there was at least one complication: dislocations — 7 (14%) cases; infection — 3 (6%); loosening — 2 (4%); complications associated with the femoral component — 4 (8%), including 3 intraoperative fractures and 1 postoperative, associated with loosening of the implant; pronounced disturbances of static and locomotor functions — 2 (4%). 12 cases out of 50 (24%) required another surgery, all of which were performed in a year. The Kaplan-Meyer survival rate for the hip implants was 0.71, for the CTAC — 0.87.Conclusion. Employment of the CTAC for revision hip arthroplasty in the patients with significant acetabulum defects and pelvic ring disruption allows reliable fixation of the endoprosthesis components. The STAC placement technique is more anatomical than use of structural allografts, several augments or sup-cage systems. It allows reconstruction of extensive bone defects, theoretically avoiding the long-term problems with allografts, modular trabecular components, antiprotrusion systems and cup-cage. Although, to prove this, the longer follow-up is needed.

Цель исследования-сравнить результаты подвертельной укорачивающей остеотомии и проксимальной остеотомии по Paavilainen при тотальном эндопротезировании тазобедренного сустава пациентам с дисплазией III и IV степеней по Crowe. Материал и методы. Было выполнено 36 операций эндопротезирования тазобедренного сустава 33 пациентам с дисплазией III (12) и IV (24) степеней по Crowe с использованием двух методик укорачивающей остеотомии:

Introduction. Additive technologies make it possible to create implants to replace bone defects. Determining the optimal parameters of a porous structure remains an urgent issue. The experimental research aimed to study the biocompatibility of implants made of titanium alloy with different pore diameters. Materials and methods. The study was carried out in two stages. The first stage included an in vitro study carried out on test cultures of diploid human fibroblasts to assess the cytotoxicity of the titanium alloy, from which samples were made for the second stage in vivo. The in vivo study was performed on three groups of rabbits (n=18), which received samples of the developed implants. The average age of subjects was 7±1 months, the weight being 4.675±258 g. All samples were 4 mm in diameter and 6 mm high. In group 1, the pore size was 100 μm; in group 2 – 200 μm; and in group 3 – 400 μm; the porosity was 55%, 62%, and 70%, respectively. The animals were sacrificed on day 90 after placement of the samples. Histological, morphological, and electron microscopic studies were performed to assess the osseointegrative properties of the implants. Results. In the in vitro study, we detected no toxic effects of the material on the test culture. In the in vivo study, the histological analysis did not reveal inflammation in peri-implant tissues in any of the groups. The morphological study showed a newly formed tissue in the area of the formed defect which consisted of young bone trabeculae with osteoblasts located on their surface. In group 3, we found the greatest prevalence of mature bone trabeculae. The samples with a 400-μm pore diameter revealed the largest area of filling the implant with newly formed bone tissue. Conclusion. Samples with a pore diameter of 400 μm have the highest osteointegrative properties. Keywords: osteointegration, biocompatibility, titanium implants, additive technologies, 3D-printing