Generating a Rabbit Calvarial Defect Model: A Surgical Procedure to Create Round Defects in the Top Portion of the Rabbit Skull to Assess Bone Substitute Materials for Bone Regeneration Capacities

First, place the rabbit on a heated pad set to 39 degrees Celsius on the surgery table, and place the rectal temperature probe. Shave the scalp. Scrub the skin with 10% Povidone-iodine to disinfect the site, then, drape the rabbit with a sterile surgical drape, and cut out an access area of the skull. Disinfect the surgical site with 10% Povidone-iodine a second time.

To begin, anesthetize locally with a subcutaneous injection of lidocaine on the skull. Use a scalpel to incise through the skin along the calvarial sagittal line, from the orbits to the external occipital protuberance, making sure that the periosteum is incised. Use a periosteal elevator to gently elevate the periosteum on both sides of the incision. Rinse the site with sterile saline.

First, locate the median and coronal sutures on the skull. Note that these anatomical lines form a cross. The cylinders will be placed in each of the quadrants defined by the cross, ensuring that the edge of the cylinder is not over the suture.

Place the first cylinder on the left upper quadrant, laying the device as flat as possible. Fix the cylinder's position with strong hand pressure, and screw in a micro-screw until resistance is felt. Ensure that the screw head is flush with the surface of the cylinder tab.

Fix the cylinder's other tab the same way to secure the cylinder tightly onto the skull. Ensure that the cylinder is hermetically fixed to the bone. Then, repeat this entire procedure to secure a cylinder onto each of the other three quadrants.

To begin, drill an intramedullary hole under saline irrigation with a round burr on the bone in the center of the area circumscribed by the cylinder. Ensure that bleeding appears. Next, drill two more intramedullary holes along the axis, passing through the two tap screws at the inner edges of the cylinder. Along the perpendicular axe, drill two more intramedullary holes at the inner edges of the cylinder.

Repeat this drilling process for the three other cylinders. Then, fill the first cylinder to the brim with the material sample. Close the cylinder by fitting the cap. Repeat this filling process for the other three cylinders. Close the skin above the cylinders with an intermittent non-resorbable suture, and apply a sprayable dressing onto the wound.

After this, stop the analgesia and anesthesia supply, and check for the recovery of autonomous breathing. Once the animal has recovered autonomous breathing, stop the ventilation. Maintain the animal under pure oxygen before complete awakening. Inject buprenorphine hydrochloride subcutaneously. Repeat the injection every six hours for three days as post-surgical analgesia. Allow the animal to awake completely before transferring it to its usual housing with water and complete feeding.