title: Is sheep lumbar spine a suitable alternative model for human spinal researches? Morphometrical comparison study.
abstract: Sheep are commonly used as a model for human spinal orthopaedic research due to their similarity in morphological and biomechanical features. This study aimed to document the volumes of vertebral bodies and compare the generated results as well as morphometry of the sheep lumbar spine to human published data. For this purpose, computed tomography scans were carried out on five adult Merino sheep under general anaesthesia. Transverse 5 mm thick images were acquired from L1 to L6 using a multi-detector-row helical CT scanner. Volume measurements were performed with dedicated software. Four spinal indices and Pavlov's ratio were calculated. Thereafter, the generated data were compared to published literature on humans. The mean vertebral body volume showed an increase towards the caudal vertebrae, but there were no significant differences between the vertebral levels (P>0.05). Compared to humans, sheep vertebral body volumes were 48.6% smaller. The comparison of absolute values between both species revealed that sheep had smaller, longer and narrower vertebral bodies, thinner intervertebral discs, narrower spinal canal, longer transverse processes, shorter dorsal spinous processes and narrower, higher pedicles with more lateral angulations. The comparison of the spinal indices showed a good similarity to human in terms of the vertebral endplates and spinal canal. The results of this study may be helpful for using the sheep as a model for human orthopaedic spinal research if anatomical differences are taken into account.
authors.affiliation: Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany. ; Department of Surgery and Anaesthesia, Faculty of Veterinary Medicine, University of Khartoum, Khartoum North, Sudan.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Mageed
authors.affiliation: Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Berner
authors.affiliation: Microsurgery and Animal Models Core, Translational Centre for Regenerative Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Henriette
authors.initials: H
authors.lastname: Jülke
authors.affiliation: Microsurgery and Animal Models Core, Translational Centre for Regenerative Medicine, University of Leipzig, Leipzig, Germany. ; Department of Neurosurgery, BG Hospital Bergmannstrost, Halle, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hohaus
authors.affiliation: Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Brehm
authors.affiliation: Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Gerlach
keywords: Comparative anatomy; human lumbar spine; ovine; spinal index; vertebral body volume