Ossification patters, non-destructive and failure responses of cervical artificial discs were determined using an in vivo Caprine model. The animals were anesthetized, discectomies were done at C3–C4, and Bryan disc, ProDisc-C, or anterior discectomy and fusion with plating (ACDF) was done. They were euthanized after monitoring for six months. Non-destructive loads were applied to the excised cervical columns in flexion, extension and lateral bending, combined with compression. The failure test was done under compression-flexion. X-rays and computed tomography scans were used to determine fusion. Force-displacement data for both artificial discs were grouped based on the presence or absence of heterotopic ossifications. They were compared with the ACDF specimens. Heterotopic ossifications occurred in both discs. Patterns of ossification were similar to those reported in civilian patients. Force-displacement responses of ossified spines were stiffer in all modes for both discs. However, differences were non-uniform. Biomechanical corridors are presented for all cases. The present preliminary study should be extended to discern the role of the disc type, loading mode and spinal level in future research.

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