Analysis of the Etiopathogenesis of Postoperative Complications in Orthopedic Patients Using Knee and Hip Arthroplasty as an Example

Relevance and Rationale Due to the widespread development of high-tech medical care in traumatology and orthopedics for patients with severe forms of hip and knee osteoarthritis and aseptic necrosis, and the increasing number of knee and hip arthroplasties, there is a proportional increase in serious complications after arthroplasty, the most serious and costly of which is the development of peri-implant infection.

Today, the prevalence of peri-implant infection is close to epidemic. It is worth noting that peri-implant infection is not always associated with poor surgical technique or the quality of prostheses.

Often, the causes of this life-threatening complication are not fully understood. Currently, no large-scale prospective or retrospective study of the causes of peri-implant infection has been conducted in Russia or in Moscow. The pathogenesis of peri-implant infection remains unexplored, and methodological approaches to its prevention and treatment have not been developed, making this topic relevant and promising. The project's results will establish the key links in the pathogenesis of peri-implant infection, define the risk spectrum for this complication, identify individual patient characteristics that increase the risk of developing this complication, determine the underlying mechanisms underlying its development, and identify alternative treatment options for these patients. Based on the data obtained, diagnostic algorithms and recommendations will be developed for treatment strategies and preoperative preparation for patients with severe forms of hip and knee osteoarthritis, femoral head fractures, and aseptic necrosis. Guidelines for the antemortem and postmortem diagnosis of peri-implant infection will also be developed. These guidelines will be used by general practitioners, rheumatologists, orthopedic traumatologists, pathologists, rehabilitation physicians, general practitioners, and endocrinologists. The program's implementation and implementation of its results are aimed at reducing the share of peri-implant infection in morbidity and mortality. 2. Objective and Tasks Project Objective: To establish the etiopathogenesis and morphological tissue changes following complications of large joint arthroplasty (PJI, aseptic instability, etc.) in patients of different age groups, assessing their somatic and immune status, calcium mineral metabolism, and its metabolism, and to develop guidelines for preoperative examination.

List of tasks to be addressed within the Project: 1. Develop a clinical study protocol; 2. Recruit a cohort of at least 600 patients for the study to conduct a comprehensive assessment of the patient's baseline status: assessment of mineral metabolism (total calcium, serum magnesium, inorganic phosphorus, 25OH, vitamin D, osteocalcin, BetaCross laps, P1NP bone matrix formation marker, parathyroid hormone); Immune status assessment (Interleukin 10 (IL-10), Interleukin 1 beta (IL-1beta, IL-1b), Interleukin 6 (IL-6), Interleukin 8 (IL-8), Complement Component C4, TNF (Tumor Necrosis Factor alpha, TNFalpha, sachectin), Lymphocyte phenotyping (main subsets panel): CD3, CD4, CD8, CD19, CD16, 56); Microbiological and PCR testing, as well as somatic status (therapist, rheumatologist) and analysis of the results of instrumental examinations (MRI, CT, densitometry, radiography). 3. The study includes a single, less often twice-time examination of each patient from the group of above-mentioned indicators at the preoperative stage. 4. Conducting a study of each patient with complications of osseointegration of the endoprosthesis from the group of above-mentioned indicators at the postoperative stage. 5. Endoprosthetics/revision endoprosthetics of the knee and hip joint. 6. Collection of tissue samples and metal structures (their fragments) from peri-implant areas for an intravital pathological examination of the patient, scanning electron microscopy, sonication, followed by microbiological examination (at least 5 samples) to characterize the microbiota in patients with developed complications.; 7. Evaluation of the obtained results of the correlation between the patient's somatic, immune, and homeostatic (mineral) status and the development of postoperative complications, statistical analysis of the data, and creation of a database.; 8. Implementation of the results of the work into clinical practice at least at the State Budgetary Healthcare Institution "City Clinical Hospital No. 31 named after Academician G.M. Savelyeva"