TESTING THE COBALT ION EMISSION ON THE STAND FOR DIFFERENT ANGLES OF POSITIONING THE COMPONENTS OF THE METAL–METAL HIP JOINT ENDOPROSTHESIS

The paper deals with the subject related to the assessment of the influence of the axis angle of the metal components of the hip joint on the emission of cobalt ions. The tribological tests were carried out with the use of a simulator for the examination of hip joint endoprostheses, the structure of which enables the fixation of endoprosthesis components in accordance with the anatomical structure of the human hip joint. During the tests, the simulator performs flexion and extension movements as well as loads occurring in the human hip joint while walking. Loss-wear tests were carried out for nine variants of the “head–cup” system settings. These settings were determined on the basis of CT images obtained from patients after arthroplasty. After the tribological tests were completed, samples of the lubricating fluid with the wear products suspended in it were collected in order to determine the concentration of cobalt ions, which was carried out using the atomic absorption spectrometry method. As a result, the influence of the head antetorsion angle (α) and the acetabular anteversion angle (β) on the concentration of cobalt ions was analysed.

Short-term results of treatment of staphylococcal periprosthetic hip joint infection with combined antibiotics and bacteriophages treatment

Infectious complications after primary implantation of the hip joint are 0.5–3 %, and in the case of re-endoprosthetics, the risk of periprosthetic infection can reach 30 %. Also, we should not forget about the high percentage (16–20 %) of recurrence of periprosthetic infection of the hip joint, which leads to an unsatisfactory result of treatment up to amputation of a limb or even death of the patient. The reasons for the recurrence of the infectious process can be antibiotic resistance and antibiotic tolerance of microorganisms, as well as the ability of microorganisms to form biofilms on implants. In this regard, there is a constant need to search for alternative means of antimicrobial therapy, as well as to select the optimal ways of their delivery and deposition, which is of practical importance when performing surgical interventions in traumatology and orthopedics to protect the implantable structure from possible infection of the surgical site. One of the methods currently available to combat bacterial infections acquired antibiotic resistance and antibiotic tolerance is the use of natural viruses that infect bacterial bacteriophages. The above suggests a more effective suppression of periprosthetic infection, including persisters that deviate from antibiotics. It is, as a rule, associated with biofilms if used in conjunction with antibiotics and phages, when the use of bacteriophages predetermines the effectiveness of treatment. With the use of sensitive bacteriophages in the treatment of periprosthetic infections, a significant (p = 0.030) reduction in the rate of recurrence of infection (from 31 to 4.5 %) was observed. The use of lytic bacteriophages in traumatology and orthopedics is of great interest for phagotherapy of infections caused by antibiotic-resistant and biofilm-forming strains of bacteria. A clinical study using a single-stage surgical revision with simultaneous application of antibiotics and phages in the treatment of deep periprosthesis infection of the hip joint endoprosthesis, followed by 12 months follow-up for periprosthetic infection recurrence, demonstrated the effectiveness of the use of combined antibiotic and bacteriophages treatment.

KONSTANTIN SIVASH - CONSTRUCTOR OF UNIQUE ENDOPROTHESIS

The author briefly describes the history of the creation of the hip joint endoprotheses, as well as the biography of Professor Konstantin Sivash, the implementator of a unique one-piece hip joint endoprosthesis, original knee and elbow joint endoprostheses, compression apparatus for the knee joint, plates and pins for osteosynthesis of fractures.

Results of surgical treatment in patients with aseptic instability of components of hip joint endoprosthesis

The aim. To study the results of revision endoprosthetics in patients with aseptic instability of the components of the hip joint endoprosthesis. Materials and methods. The basis of this work was the analysis of the revision prosthetics results in 152 patients (158 cases) with aseptic instability of components of hip joint endoprosthesis, who underwent surgery at the State Institution “Institute of Traumatology and Orthopedics of the National Academy of Medical Sciences of Ukraine” between 2008 and 2018. Total instability in the endoprosthesis components was observed in 43 cases (27.2 %), acetabular component instability – in 65 cases (41.1 %), femoral component instability was detected in 50 cases (31.6 %). Endoprosthesis dislocation occurred mostly between 5 and 9 years after the primary surgery. Clinical, radiological and statistical methods were used in the work. Results. Patients with acetabular component instability showed the best results of revision replacement for Paprosky I, II types acetabular defects (t = 9.3, P < 0.05). The vast majority of components became unstabile between 5 and 9 years after the primary replacement. The results of unstable femoral component revisions did not reveal any significant difference between cemented and cementless types of component fixation 10 years after the procedure. Recurrent aseptic instability was observed only in 7 cases, 5 of which (71.4 %) were fixated with cement. In the case of total instability, there was no difference in the revision implantation results between the use of primary components alone and in the combination with revision reconstructive systems. Component stability constituted the great majority (35 cases, which was 81.4 %) of cases after 10 years (t = 7.3, P < 0.05). The recurrent instability of one component was observed in 8 cases, which represented 18.6 % of the total number of revisions. Conclusions. In patients with instability of acetabular and femoral components in the presence of Paprosky I–II bone defects, the results of the revision replacement were better when implanting primary components using cementless type of fixation. The use of revision antiprotrusion acetabular and elongate femoral modular or monoblock systems with cementless type of fixation achieved better results in Paprosky III type acetabular and femoral bone defects. The revision of cemented components showed significantly worse results and implant survival rate compared to cementless fixation technique.

Study of Contact Pressures in Total Hip Replacement

Total hip arthroplasty is a complex procedure. The achievements of implantology enabled the development of a faithful representation of hip joint physiology as well as the production of materials that can successfully replace damaged natural tissues. A very important issue is the correct selection of the geometry of the endoprosthesis adequate to the load of the joint. Materials used for endoprosthesis are a metal head and a polymer cup (e.g. PE-UHMW). The main interactions in the endoprosthesis are friction and surface pressure, which must be limited, exceeding them causes the destruction of the biomechanical system - plastic deformation of the polymer and the formation of too large and unacceptable radial clearances. Based on the author's developed calculation method of hip joint endoprosthesis contact parameters, the impact on maximum contact pressure and the angle of contact of the joint load was estimated depending on the diameter of the endoprosthesis and radial clearance. The correctness of changing the values of maximum contact pressure from the mentioned parameters was determined. Correspondingly: an increase in joint load causes a linear increase in the maximum contact pressure; increasing the diameter of the endoprosthesis head - their non-linear decrease, and increasing radial clearance - their increase

Impact of Digital Supported Process Workflow Optimization for Hip Joint Endoprosthesis Implantation on Hospital - Specific Process and Quality Ratios

Considering the continuous change within the German health care system, German hospitals are forced to realize efficiency gains and, at the same time, try to enhance their quality standards. Digital support systems in surgery rooms intend to improve operational efficiency and reduce failure quotas. A dataset with 383 hip joint endoprosthesis surgeries from a German hospital was analysed using statistical methods, among others logit model, odds ratio and ANCOVA. Results show that digitally supported surgery results in a shorter hospital stay time and reduces acute hemorrhagic anemia as a postoperative complication. Finally, it is possible to conclude that the Surgical Procedure Manager reduces surgical risks.

Effect of age on the functioning of hemostasis system during hip joint endoprosthesis

The study was performed on 109 osteoarthritis patients who underwent hip joint endoprosthetics; the effect of age on changes in hemostasis system, blood loss level and deep veins thrombosis development in the background of standard prevention with low-molecular heparins were studied. Before the surgery, it was determined that 56 elderly patients (60.3 ± 6.4 years) compared to 53 middle-aged patients (41.8 ± 6.8 years) had a significantly higher initial and postoperative endothelial dysfunction, higher fibrin formation and lower anticoagulant potential; however, it was found that on the background of pharmacological anticoagulant therapy the changes in the hemostasis functioning in elderly patients did not lead to an increase of either blood loss or the number of thromboses.