Recently, interbody fusion cage devices have been developed and used for lumbar reconstruction. Stand-alone cages reduce segmental mobility. In this study, we evaluated mechanical properties and biocompatibility of lumbar stand-alone cages. Evaluation of mechanical properties followed the ASTM F2077 standard that covers methods for static and fatigue testing. The sterility test was ensured by the ISO 11737-2. The extractable substances test was ensured by the Korea pharmacopoeia. Cytotoxicity of the specimen was assessed using MTT assay as recommended by the international standard guidelines, ISO 10993-Part 5 for in vitro testing.

Stand-alone cervical cage consists of a PEEK body, Ti plate, and screw, which are configured as a single-piece. Through a single operation, this implantable medical device is capable of completely fixing the cervical vertebral body. For example, instead of a plate, which is normally used, the intervertebral disc is removed and replaced with a cervical cage. It should be noted that in Korea, KFDA guidelines for a stand-alone cervical cage have not yet been suggested. Therefore, the aim of this study is to present the systematic study of the static compression test, static torsion test, dynamic compression test, and expulsion test. Further, the test method is designed to refer to the ASTM standard and relative literature.