No abstract

In view of the increasing number of hip joint replacement volume there remains the key issue of improving prosthesis survivorship which directly depends on the friction couple. Material and methods. The authors have analyzed five year outcomes of two bearing types (head and insert) used in hip replacement: ceramic-on-ceramic (CoC) in 324 patients and ceramic-on-polyethylene (CoP) in 300 patients. Totally 550 patients were operated in the period starting 2010 till 2014, including 74 patients underwent bilateral hip replacement. The authors divided patients based on gender and also into three age groups: 20-40, 41-60 and 61-80 years old. The largest group comprised 156 women aged 41-60 years (28.4%). Additional grouping of patients was made based on gender, age and bearing diameter.36 mm diameter bearing was characterized of the most frequent use. Functional outcomes were assessed by Harris Hip Score. Statistical analysis was made with Statistica 10 software. Statistical significant was observed at p0.05.Results.28 mm diameter bearing were rarely (19.5%) applied and mainly in women which is related to need for use of smaller acetabulum components and inability to implant a larger insert.36 mm diameter bearing were used most frequently, CoC articulation of36 mm was used in men in 34% of cases and in women – in 18.12% of cases.40 mm articulations were implanted in women two times less than in men which is related to a smaller diameter of acetabulum in women. Generally, CoC bearings were implanted more often in men which can be explained by a bigger social demand as well as a higher anti-luxation stability of large diameter bearings. Dislocations of implants occurred in 5 (0.91%) patients: in 4 patients with CoP bearingand in one patient with CoC articulation. Four revision procedures (0.64%) were made due to deep periprosthetic infection: two surgeries in each group. Harris Hip Score evaluation in CoC group demonstrated excellent and good outcomes in 99.2% of cases, and in CoP group – in 97.5% of cases.Conclusion. The authors observed no ceramic fractures or acoustic effects during 60 months follow up. It’s reasonable to increase CoC bearing diameter to achieve a better anti-luxation effect. CoC bearing selection should depend on patient’s activity and social demands but not only on the age. Based on study observations the authors forecast a higher survivorship of CoC couple within 15-20 years and expect to prove this conclusion in further studies.

Relevance. Late deep periprosthetic infection (PJI) of the hip joint is a serious complication after arthroplasty which takes the lead among the world reasons for revision. Accurate diagnostics allows to achieve good results and select a proper treatment tactics. Purpose of the study — to evaluate the efficiency of diagnostics algorithm for late deep PJI and impact of the microbial landscape on the risk of infection recurrence. Materials and methods. The authors evaluated two groups of patients who underwent revision in the period from 2002 to 2014 and from 2015 to 2018. The first (retrospective) group included 144 patients who were not diagnosed for late deep PJI. The second (prospective) group included 157 patients who underwent detailed diagnostics for late deep PJI based on the algorithm including the analysis of x-rays, pelvic CT, triple evaluation of ESR and CRP, puncturing of affected joint and microbiology examination. The authors assessed the microbial landscape in 51 patients with late deep hip PJI. Results. In the first group 12 patients (8.3%) underwent sanation and spacer insertion during first stage of treatment, 46 patients (59.7%) after revision demonstrated positive intraoperative cultures confirming septic etiology of implant loosening, 19 patients (24.67%) had no flora growth, and no intraoperative microbiological examination was done for remaining 67 patients (46.52%). In the second group after detailed diagnostics 51 patients (32.4%) underwent removal of prosthesis and spacer insertion in the first stage, other 13 patients (8.2%) featured flora growth after revision, remaining 93 patients (59.2%) had no flora growth after revision. Recurrent PJI was observed in 21 patients (14.5%) in the first group, and in 10 patients (6.3%) in the second group. In the second group recurrent PJI was reported in 40% of patients due to microbial associations, in 30% — due to MRSA, in 20% — due to culture negative bacteria and in 10% — due to S. aureus. Conclusion. Triple examination allows to obtain an accurate diagnosis and isolate the pathogen for deep PJI. Application of such diagnostics algorithm allows to reduce 2.1 times the risk of recurrent deep PJI and to scale down 4 times the detection of type IV infection by Coventry–Tsukayama classification.