Anatomical Surgical Landmarks in Canine Thoracolumbar Surgery: A Cadaveric Study

Thoracolumbar surgeries in canines have become increasingly important in veterinary surgery, requiring precise anatomical knowledge to accurately identify the site of the lesion during surgery. This accuracy is crucial to minimize the risk of wrong-site spinal surgeries (WSSS). This study aims to identify reliable and practical anatomical landmarks in the thoracolumbar region. In addition to existing landmarks and imaging techniques, the identified landmarks may aid surgeons in safely orienting themselves during operative procedures and ensuring the correct surgical site during the surgical approach. Nine cadavers were examined. After thawing, dissections were performed to identify anatomical landmarks between the tenth thoracic and first lumbar vertebrae. Additionally, the intercristal line has likewise been investigated as landmark caudal to the thoracolumbar region. Mammillary processes were palpable at T12-T13 and most
prominent at T13-L1. The facet joints displayed a horizontal orientation at T10-T11 and a vertical caudo-dorsal, better palpable orientation at T11-T12. The spinalis and semispinalis musculature are consistently inserted into the mid-layer of the thoracolumbar fascia at the level of T11. The tendons of the lumbar longissimus attached to the L1 accessory process. The intercristal line consistently marked the L6-L7 interspinous space across all specimens. These landmarks
provide practical intraoperative guidance for thoracolumbar surgeries. This study provides less-known anatomical structures to the currently known and used landmarks, supporting their use for preoperative planning and intraoperative navigation. Combining these anatomical findings with digital imaging techniques may enhance surgical accuracy and therefore reduce the risk for WSSS.