Fig. 1From: Intervertebral-spreader-assisted anterior cervical discectomy and fusion prevents postoperative axial pain by alleviating facet joint pressureCervical vertebral spreader and its usage in vertebral distraction. A Typical images of vertebral spreader. B The Caspar distraction device is first used after removal of the intervertebral disc, and then the vertebral spreader is used to further enlarge the disc space. C The illustration showing the measurement method of intervertebral disc height (IDH), change of IDH (â–³IDH) and interfacet distance (IFD)Back to article page