Interspinous fusion device: A systematic review of clinical and biomechanical evidence

To assess the biomechanical and clinical evidence available in use and efficacy of interspinous fusion devices and to explore indications for their application. MEDLINE search and Google Scholar were employed to find the relevant papers through the following key words: interspinous fusion, interspinous fixation, and posterior instrumentation. Based on their fixation modes and fused sites, the related classification for interspinous fusion devices will be established, and a systematic review of clinical and biomechanical studies was made. The results revealed that a total of 13 kinds of interspinous fusion devices were obtained, and they were classified into two main categories: (1) “interspinous fixation without situ fusion” type (or rigid interspinous fusion device) and (2) “interspinous fixation with situ fusion” type (or fused interspinous fusion device). Furthermore, a summary on its biomechanical and clinical study was given, which showed that interspinous fusion device could provide excellent biomechanical efficiency and promising clinical success. In conclusion, interspinous fusion device construct is a new potential fixation technique. However, further high-quality studies are still needed to clarify their long-term efficacy and indications for their use.