Histological Evaluation of the Sheep’s Cervical Spine Segment 3/4 – A Histomorphological and Histomorphometrical Study

Summary The 2‐year‐old sheep is a frequently used model in spinal orthopaedic research; however, so far no investigations have been performed on physiological tissue of untreated animals. In this study, the cervical spine segment 3/4 of eight 2‐year‐old female Merino sheep was evaluated histologically and histomorphometrically. Specimens were stained with Masson‐Goldner‐Trichrome, Safranin‐Orange/Lightgreen, Safranin‐Orange/von Kossa and Astrablue. Analysis of bone mass, mass of cartilage and mineralized cartilage in a defined region of interest was performed. A new finding of the study was that – although 2‐year‐old sheep is regarded as adult – tissue of the growth plate was still detected. Moreover, this study revealed that in the nucleus pulposus of the 2‐year‐old sheep notochordal cells are still existent, suggesting a complex remodelling of the nucleus pulposus in sheep.