Surgical Induction of Lumbar Spine Instability in Mouse Model: A Surgical Procedure for the Resection of the Lumbar Spinous Processes and Connected Ligaments in Murine Model

After confirming a lack of response to fetal reflex, place an anesthetized eight-week-old male C57 Black 6 mouse onto a surgical pad in the supine position, and apply ointment to the animal's eyes. Use a small animal trimmer to shave the surgical area from the lower thoracic region to the top of the sacral region and remove the shaved fur with tissue wipes.

Apply depilatory cream to the shaved area, using gauze to remove the cream, after no more than three minutes and flush the exposed skin with 2 milliliters of 0.9% sterile saline. Then, place a custom-made surgical cylindrical pad under the abdomen to raise the lumbar spine.

To expose the L3 and L5 vertebrae, use the index finger to touch the subcutaneous spinous processes of the lumbar vertebrae and palpate to compare the processes with those of the thoracic vertebrae and sacral vertebrae, to identify the lumbar region.

Rinse the skin with 75% alcohol, and using a dissecting microscope, use a scalpel to make a 3 to 4-centimeter midline skin incision over the lumbar region, from the mid-thoracic region to the hip. Identify the lumbar spine by the V-shape of the posterior fascia inserted into the tips of the spinous processes, and use the scalpel to make shallow posterior paraspinous muscle incisions, along the spinous processes, from L3 to L5 laterally on both sides of the spine. Then, use two pairs of ophthalmic forceps to separate the muscle layers, to expose the L3 to L5 spinous processes and supraspinous ligaments.

To separate individual spinous processes, use Venus shears to cut off intraspinous ligaments, and to resect the L3 to L5 spinous processes and intraspinous ligaments. Then, use sterile number 5 Silk braided sutures to close the skin incision without reattaching the paravertebral muscles, and apply chloride tetracycline hydrochloride ointment to the surgical site.