Safety and functional evaluation of a synthetic lamina cover that replaces lost autologous spinal bone after laminectomy, in a sheep and human study.

Background: Laminectomies involve removal of the lamina, usually to relieve pressure on the spinal cord. We are developing a synthetic lamina cover (SLC) that can replace the resected bone, functioning as an artificial shield, with the objective to minimize common postsurgical risks associated with laminectomies. The SLC is designed to be affixed to a common pedicle screw fixation system. Methods: Lumbar laminectomies with posterior fusions were performed in 6 sheep and 30 human patients. Both cohorts were separated into 2 groups, where 1 group received the SLC to replace the lamina, whereas the other group did not. Otherwise, postsurgical care and medical attention were the same in both groups. After 26 weeks, the sheep were euthanized and histopathological and histomorphometrical evaluation of spine sections was performed. Human patients were followed for up to 6 months, and functional recovery was evaluated using the Oswestry Disability Index (ODI) questionnaire. Results: In sheep, the overall host tissue response was minimal, without any signs of irritation, inflammation, or aberrant changes potentially caused by the SLC. Human patients that had received the SLC reported better and faster functional recovery (p<.05) than the group without the SLC. Neither patient group experienced complications from surgery. Conclusions: Application of the SLC was safe and showed benefit as a shield to replace the autologous spinal lamina postlaminectomy. In its presence, functional recovery not only was faster, but also overall more pronounced.