Lab Anim Res.  2013 Dec;29(4):183-189. 10.5625/lar.2013.29.4.183.

Is sheep lumbar spine a suitable alternative model for human spinal researches? Morphometrical comparison study

• Mageed M
• Berner D
• Julke H
• Hohaus C
• Brehm W
• Gerlach K

• KMID: 1716212
• DOI: http://doi.org/10.5625/lar.2013.29.4.183

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.

Keyword

Comparative anatomy; human lumbar spine; spinal index; ovine; vertebral body volume

MeSH Terms

Adult
Anatomy, Comparative
Humans*
Intervertebral Disc
Sheep*
Spinal Canal
Spine*
Tomography, Spiral Computed

Figure

• 

  Figure 1 Estimation the vertebral body volume using ImageJ. The vertebral body was outlined (yellow stars), subsequently the Volumest plugin calculates automatically the volume from the area (red stars) and the slice thickness of each image. Finally, these values per image were added up to calculate the volume.

• 

  Figure 2 The means of the vertebral body volumes (cm3) of the sheep using imageJ software compared to real volume of the same vertebrae, which was measured using fluid displacement technique.

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