Non-fusion technology in degenerative lumbar spinal disorders: facts, questions, challenges.

Although surgical fusion of the painful degenerating functional spinal unit (FSU) of the lumbar spine has always been a matter of debate, it has become a gold-standard procedure for all cases that lack an alternative treatment. However, a detailed and honest review of the clinical data reveals a considerable number of undesired side effects, complications and poor outcomes. The continuous search for alternative surgical treatment modalities has led to the development of numerous ideas for surgical reconstruction of the anterior and/or posterior column. The term "spine arthroplasty" summarises all procedures that have the goal of restoring function. This article describes the principles of the most current surgical techniques and implants, it points out potential challenges and poses a number of questions that need evidence-based answers before the incorporation of these innovations into surgical routine can be justified.