Poly(methyl methacrylate) Bone Cement Composite Can Be Refilled with Antibiotics after Implantation in Femur or Soft Tissue

While periprosthetic joint infections (PJIs) result in a small percentage of patients following arthroplasties, they are challenging to treat if they spread into bone and soft tissue. Treatment involves delivering antibiotics using poly(methyl methacrylate) (PMMA) bone cement. However, antibiotic release is insufficient for prolonged infections. Previous work demonstrated efficacy of incorporating insoluble cyclodextrin (CD) microparticles into PMMA to improve antibiotic release and allow for post-implantation drug refilling to occur in a tissue-mimicking model. To simulate how antibiotic refilling may be possible in more physiologically relevant models, this work investigated development of bone and muscle refilling models. The bone refilling model involved embedding PMMA-CD into rabbit femur and administering antibiotic via intraosseous infusion. Muscle tissue refilling model involved implanting PMMA-CD beads in bovine muscle tissue and administering antibiotic via tissue injection. Duration of antimicrobial activity of refilled PMMA-CD was evaluated. PMMA-CD composite in bone and muscle tissue models was capable of being refilled with antibiotics and resulted in prolonged antimicrobial activity. PMMA-CD provided sustained and on-demand antimicrobial activity without removal of implant if infection develops. Intraosseous infusion appeared to be a viable technique to enable refilling of PMMA-CD after implantation in bone, reporting for the first time the ability to refill PMMA in bone.

The first domestic devices for intraosseous infusion - is the great advance of military medicine in pre-hospital stage enhancement

Traumatic shock is considered to be the most common clinical form of a severe patient’s condition (63%). Timely and adequate blood volume resuscitation is one of the most important procedures in providing medical care to critically injured casualties and patients at the forward medical evacuation stage. The key to this problem, especially when the infusion therapy is needed at the pre-hospital stage, is the development of alternative (extravascular) techniques of plasma volume expander administration. The article presents the results of testing of the first domestic medical devices for intraosseous infusion in critically injured casualties and patients. At present, on commission of the Russian Ministry of Defense and with the scientific support of Kirov Military Medical Academy, domestic enterprises developed test samples of medical devices to provide intraosseous infusions: a «Disposable device for intraosseous infusion of solutions if there is no intravenous access, which was designed on the basis of a spring drive» - the index «VKI-P», developed by limited liability company «Novoplast-М» and a set for intraosseous infusion using an electric drive - the index « VKI-E», developed by limited liability company «Research engineering company «Spetsproekt». Assessment of performance of test samples of the medical devices for intraosseous infusions «VKI-P» and «VKI-E» was carried out using pathophysiologic model of traumatic shock in 14 experimental animals (pigs) by creating artificial blood loss of medium severity, 25% of circulating blood volume (in average 440 ml), followed by its resuscitation with intraosseous infusion of 0,9% solution of NaCl. As a result of the performed tests it was found that the device «VKI-P» and the set «VKI-E» provide for NaCl infusion in major vessels (with an intraosseous infusion), 750 ml of volume during 45-50 min, and can be used as an alternative access to provide infusion as a part of anti-shock therapy, which solves the problem of volume resuscitation when giving care to severely injured casualties and patients at the forward medical evacuation stages. These samples may be recommended for inclusion into the medical service list of complete supplies and the Medical Corps supply support, the Armed Forces of the Russian Federation.