Preparation, release profiles and antibacterial properties of vancomycin-loaded Ca-P coating titanium alloy plate.

The aim of the study was to explore the feasibility of the Ca-P coating titanium alloy plate to be used as the vancomycin drug-delivery system by biomimetic coating technology. Through the X-ray diffraction study, the main components of the coatings were identified as octocalcium phosphate. The in vitro vancomycin release, bacteriostasis activity to Staphylococcus aureus (S. aureus), the scanning electron microscope (SEM) image and osteoblast adhesion and proliferation test of vancomycin-loaded Ca-P coating plate were evaluated. The bacteriostatic activity of the vancomycin-loaded Ca-P coating plate showed a continuous drug release and had an inhibitory effect on the growth of the S. aureus. In vitro osteoblast culture results showed that the Ca-P coating plate loaded with or without the vancomycin both obviously promoted the osteoblast attachment. It was suggested that the vancomycin-loaded Ca-P coating may be compounded in the surface of the internal fixators to reduce the incidence of the implant-associated infection.

Antibiotic-impregnated cement spacer versus antibiotic irrigating metal spacer for infection management after THA.

We prospectively compared the effects of an antibiotic-impregnated cement spacer and an antibiotic irrigating metal spacer in the treatment of infections after total hip arthroplasty (THA) to determine a better method for 2-stage revision of infected THA. We used a uniform protocol of a 3-month spacer interval and specific local and systemic antibiotic therapies. The clinical outcome was determined by assessing operation time, blood loss during spacer implantation, hospital stay and time in bed, and joint function. The patients were followed for a mean 61.4 months (range, 24-94 months). Antibiotic-impregnated cement spacers had a higher rate of infection control than antibiotic irrigating metal spacers (96.2% vs 76%, respectively; P<.01), with no recurrence of infections or implant loosening. Patients receiving antibiotic-impregnated cement spacers had a shorter operation time (2.42±0.65 vs 3.34±0.36 hours metal spacers; P<.01), less blood loss (1085.48±279.49 vs 1964.78±469.23 mL metal spacers; P<.01), a shorter hospital stay (24.53±4.72 days vs 51.36±3.46 days metal spacers; P<.01), and better function before the second step of the 2-stage revision (Harris Hip Score, 88.16±6.94 vs 79.54±6.48 metal spacers; P<.05), and they were free from long-term irrigation. Compared with the antibiotic irrigating metal spacer, the antibiotic-impregnated cement spacer is characterized by higher infection control rate, better joint function recovery before the second operation, shorter operation time, and less blood loss, with no continuous irrigation required.

Efficacy of a norvancomycin-loaded, PDLLA-coated plate in preventing early infection of rabbit tibia fracture.

Despite improvements in surgical techniques and implant designs in orthopedic surgery, implantation-associated infections are still a challenging problem for surgeons. The goal of this study was to evaluate the efficacy of a norvancomycin-loaded, PDLLA-coated stainless steel plate vs an uncoated stainless steel plate in a rabbit model (n=50). The norvancomycin was delivered from a biodegradable poly(D,L-lactide) (PDLLA) coating of a stainless steel plate. Intraoperatively, rabbit tibia fractures were contaminated with Staphylococcus aureus (10(5) colony forming units) after plate implantation. The implants were either uncoated or coated with PDLLA and norvancomycin. In vivo drug release profiles showed that the norvancomycin release rate was decreased by increasing the time. The norvancomycin concentration in the tissue around the plate was higher than the minimum inhibitory concentration on the 14th day after implantation surgery. The animals were followed up for 28 days. Radiographic examinations were performed, and C-reactive protein and erythrocyte sedimentation rate were determined. Infection was evaluated by histological, microbiological, and radiological analysis. Eight of 25 rabbits (32%) implanted with the norvancomycin-loaded, PDLLA-coated plates were infected. Twenty-three of 25 rabbits (92%) implanted with the uncoated plates were infected (P<.05). The norvancomycin-loaded, PDLLA-coated plate may be used to treat open fractures to reduce the incidence of early infection.