Efficacy of Platelet-rich Plasma Impregnation for Unidirectional Porous Β-tricalcium Phosphate in Lateral Lumbar Interbody Fusion: Study Protocol for a Randomized Controlled Trial

BackgroundPlatelet-rich plasma has been increasingly used in spinal fusion surgery. However, the efficacy of platelet-rich plasma in lateral lumbar interbody fusion is unclear. In Japan, Affinos® (Kuraray Co., Tokyo, Japan), which is a β-tricalcium phosphate artificial bone, has been increasingly used for spinal fusion as a bone graft. The purpose of this trial is to demonstrate whether Affinos® impregnated with platelet-rich plasma can achieve a higher fusion rate, more rapid fusion, and better clinical outcomes than Affinos® alone.Methods/DesignThe current study is a prospective randomized controlled trial. The current trial will include consecutive patients scheduled for lateral lumbar interbody fusion. Since an intervertebral cage for lateral lumbar interbody fusion has two spaces for a bone graft, two bone grafts are inserted for each intervertebral level. In the current study, an artificial bone with plate-rich plasma will be inserted into one space and an artificial bone without platelet-rich plasma will be inserted into the other space. We will compare the fusion rates between the bone graft with and without platelet-rich plasma. Our primary endpoint will be the interbody fusion rate at 1 year after surgery. DiscussionThe current trial will verify the efficacy of platelet-rich plasma with Affinos® for bony fusion in lateral lumbar interbody fusion. This trial will provide substantial evidence for the effectiveness and safety of platelet-rich plasma in spinal fusion surgery.Trial registrationJapan Registry of Clinical Trials (jRCT), ID: jRCTb032200199. First registered on 13 November 2020, https://jrct.niph.go.jp/latest-detail/jRCTb032200199. jRCT is approved as a member of the Primary Registry Network of WHO ICTRP.