Animal Model for Anterior Lumbar Interbody Fusion: A Literature Review

Lumbar interbody fusion (LIF) is a surgical procedure for treating lumbar spinal stenosis and deformities. It removes a spinal disc and insert a cage or bone graft to promote solid fusion. Extensive research on LIF has been supported by numerous animal studies, which are being developed to enhance fusion rates and reduce the complications associated with the procedure. In particular, the anterior approach is significant in LIF research and regenerative medicine studies concerning intervertebral discs, as it utilizes the disc and the entire vertebral body. Several animal models have been used for anterior LIF (ALIF), each with distinct characteristics. However, a comprehensive review of ALIF models in different animals is currently lacking. Medium-sized and large animals, such as dogs and sheep, have been employed as ALIF models because of their suitable spine size for surgery. Conversely, small animals, such as rats, are rarely employed as ALIF models because of anatomical challenges. However, recent advancements in surgical implants and techniques have gradually allowed rats in ALIF models. Ambitious studies utilizing small animal ALIF models will soon be conducted. This review aims to review the advantages and disadvantages of various animal models, commonly used approaches, and bone fusion rate, to provide valuable insights to researchers studying the spine.