This article describes a method for generating a bacterial bone infection model using a New Zealand white rabbit. The procedure involves inoculating the tibia with Staphylococcus aureus to study the resulting osteomyelitis.
To generate a bacterial bone infection model, begin by placing an anesthetized rabbit in a lateral position. Remove the fur from the hindlimb to locate tibia - the bone connecting the knee to the ankle. Mark a point adjacent to the tibial plateau - the proximal end of tibia bone.
Incise the skin and periosteum - a tissue layer around the bone - exposing the tibia. Using the marked reference, make a cavity in the bone marrow. Insert a bone wax plug into the cavity. Suture the periosteum and the skin layers.
Next, take a syringe containing Staphylococcus aureus solution. Pierce the needle through the bone wax plug and inoculate the bacterial solution into the bone marrow. Eject the needle. Transfer the rabbit to a cage and monitor the spread of infection.
The bone wax plug prevents the leakage of the bacterial suspension, allowing the bacteria to proliferate in the bone marrow. These bacteria attract the leucocytes and inflammatory factors leading to osteomyelitis - an inflammation in the bone causing reduced blood supply.
These conditions eventually lead to the sequestrum formation - a necrotic area in the bone devoid of blood supply. Bacteria further infiltrate this area to escape the antibiotic treatment, resulting in a chronic infection.
To set up the bone infection mold, confirm a lack of response to paw pinch in a three-month-old, 3-kilogram male New Zealand white rabbit, and use an electric shaver to remove the hair from the proximal tibial region against the direction of the hair growth. Disinfect the exposed skin with povidone-iodine solution, and use a pen and a ruler to mark the upper end of the tibia, and the drilling hole position for the S. aureus injection, taking care that the drilling hole position is in the horizontal middle of the tibial plateau.
Next, use a #11 scalpel to make an incision in the skin, followed by a 1-centimeter incision in the peritoneum. Using an electric bone drill unit, punch a 2-millimeter diameter hole in the tibia, and press the hole with a 2-millimeter diameter, 2-millimeter long, cylinder of bone wax. Remove any spare bone wax along the horizontal plane of the tibial plateau, and confirm that the hole is full of bone wax.
Then, use absorbable surgical sutures to sew up the periosteum and skin, in a vertical mattress suture to prevent the animal from chewing the stitches, and use a 1-milliliter asepsis injector to slowly inject 1 x 108 CFU/mL of S. aureus solution into the drill hole.
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