First we’re gonna start with there’s a couple of different types and causes of spondylolisthesis which we have a list of we’re gonna really focus on the first to dr. if that’s okay but I do want to just chime in on all of numbers the first time first one is degenerative obviously that’s age related definitely so if a disc degenerates which happens in all of us sometimes imagine again if a vertebra sort of come closer together and they settle normally then that’s what happens to most people but looking from the side if the disc degenerates and the vertebra kind of shift forwards you develop what’s called degenerative spondylolisthesis all right the second one there is developmental with young athletes definitely so that’s the one where kids will have a failure of formation of one little bony bridge so they’re born like that well essentially yeah a bony bridge fails to form and it allows a certain discontinuity between the joints in the back of each vertebra that keep the spine in its perfect upright posture it disconnects those bones from the front of the spine and that once again allows the spine to shift and those are the two that we’re gonna focus on this hour but let’s just briefly go through traumatic tumor and post-surgical so traumatic meaning that that same bony bridge that’s missing and kids can be fractured and traumatic actually I see more and more now as my competitive athletes especially guys that do baseball golf rotational type sports they develop a stress fracture of the same bony bridge a tumor at that region can also occur and once again it can disconnect the back from the front of the spine allowing a shift but that’s rare and post-surgical obviously that’s after surgery how does that happen so I’ve seen that as well really definitely especially with younger surgeons that are doing minimally invasive technique where they don’t feel comfortable with the anatomy they will do a diskectomy or a decompression type surgery where you have to remove a little bit of bone but they won’t see the entire bridge of bone and just keep taking taking taking until they destabilize the spine so essentially going at that same bone that’s missing and kids are broken as a stress fracture and athletes sometimes that can be sort of taken away by a bad operation once again resulting in instability