Two kinds of calcium phosphate ceramic (CPC) granules of high porosity (50 +/- 5%) and improved (for such materials) compressive strength (10-25 MPa) consisted of hydroxyapatite (PHA) and a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) in 60 HA/40 beta-TCP composition (PCPC) were developed. A comparative study of in vivo behavior of the materials implanted into an almost unloaded (greater trochanter of femur) and loaded (distal methaphysis of femur) zones in the skeleton of rabbits was performed. Significant activating influence of loading on the processes of new bone formation and reconstruction in macropores of both materials during all periods of implantation (up to 6 months) was observed. The role of relevant cells in the processes in the unsoluble PHA and the degradable PCPC (in which the processes was observed to intensify due to dissolution of the material) was studied and is discussed. Great disturbance in pore structure of the BCPC was revealed in more late periods of implantation. After 6 months, presence of large composite fragments located in intertrabecula spaces of greater trochanter was a characteristic feature of the PCPC crushing. The developed CPC materials seems to have good perspective for using in bone defect plasty in some loaded areas of the skeleton.
Background. The reconstruction of long bone defects that occur after resection of tumors is a problem that requires constant study. Bone allografts are often used in this scenario. Unfortunately, while they are prepared, allografts partially lose their strength and osteoinductive properties; their survivability in oncological patients is only 40% after 10 years. This is why the search for superior allograft treatment methods and the study of allograft remodeling and incorporation in oncological patients, whose state has been affected by radiation or chemotherapy, is an area of interest. Purpose – study the structure of bone tissue in the distal metaphysis of a rat’s femur after bone allograft implantation (sterilized using gamma radiation or antibiotic saturation) and post-operative intraperitoneal cisplatin injection. Materials and Methods. Experiments were performed on 20 male white rats aged 5–6 months at the beginning of the experiment and weighed 365.8 ± 6.4g. All rats underwent a surgery that created a defect in the distal metaphysis of the femur which was filled with a bone allograft treated with gamma radiation (Control-1 and Experimental-1 groups) or saturated with an antibiotic (Control-2 and Experimental-2 groups). 14 days after allograft implantation, animals from the control groups received an intraperitoneal injection of 2.0–2.4 ml of 0.9% NaCl, while animals from the experimental groups received 2.5mg/kg of cisplatin. Histological analysis and histomorphometry were completed 30 days after the surgery. Results. 30 days after the operation, the smallest relative area of bone tissue (11.79%) was observed in rats from the Experimental-1 group, with gamma radiation treated allografts and post-operative intraperitoneal cisplatin injections. A somewhat higher value was found in the Experimental-2 group (antibiotic saturation + cisplatin) – 31.64%. In the control groups, (intraperitoneal injection 0.9% NaCl), the relative area of bone tissue was 16.7% (Control-1, gamma radiation treatment) and 58.09% (Control-2, antibiotic saturation). The relative area of fibrous tissue was the largest in the Experimental-1 group – 31.55% and the smallest in the Control-2 group – 12.79%. Conclusions. Allograft remodeling occurs along with the formation of bone and fibrous tissue when allografts are used to fill defects in the distal femoral metaphysis of rats, However, the relative percentages of those tissues depend on the allograft sterilization method and the use of cytostatic agents. The largest relative percentage of bone tissue (58.09%) was obtained using an allograft saturated with antibiotics and without the administration of cisplatin. The smallest (11.79%), on the other hand, occurred in gamma radiation treated allografts with cisplatin injected intraperitoneally after the operation
Харківська медична академія післядипломної освіти МОЗ України 2 ДУ «Інститут патології хребта та суглобів ім. проф. М. І. Ситенка НАМН України», Харків Цель: оценить структурно-функциональное состояние коленного сустава крыс после моделирования посттравматической внесуставной деформации бедренной кости. Методы: эксперименты выполнены на 39 белых половозрелых (возраст 6 мес.) крысах-самцах. Для моделирования деформации varus (опытная группа, 15 крыс) после поперечной остеотомии бедренной кости в костномозговой канал вводили изогнутый под углом 35° стержень, контрольным животным (15) -прямой. Группой сравнения были интактные крысы (9) соответствующего возраста и пола. Через 1, 3 и 6 мес. после операции выполнено гистологическое исследование. Результаты: через 1 мес. после моделирования деформации в суставном хряще (СХ) коленного сустава отмечены деструктивные изменения 1-2 степени по OARSI. В контралатеральной конечности СХ имел характерное для возрастной нормы строение. Через 3 мес. установлено уменьшение ширины СХ (по сравнению с интактной группой в 1,21 раза, p < 0,01), потерю гликозаминогликанов, нарушение структуры и упорядоченности коллагеновых волокон, накопление коллагена I типа. Через 6 мес. наиболее выраженные нарушения выявлены в СХ на медиальном мыщелке деформированной бедренной кости -уменьшение его ширины по сравнению с интактной группой в 1,63 раза (p < 0,001), местами замещение волокнистым хрящом. Выводы: у животных с моделированной внесуставной деформацией бедренной кости в СХ коленного сустава травмированной конечности через 1 мес. выявлены деструктивные изменения, которые прогрессировали со временем. Через 1 мес. максимальное проявление нарушений отмечено в зоне поверхности бедренной кости под надколенником, а через 3 и 6 мес. -медиального мыщелка. В СХ коленного сустава контралатеральной конечности деструктивные изменения зафиксированы через 3 мес. после воспроизведения деформации, однако выраженность проявлений была меньше. Ключевые слова: посттравматическая деформация бедренной кости, коленный сустав, крысы, остеоартроз, гистологические изменения.
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