A Critical Look at How the Eagles Franchise QB was Diagnosed with a Puzzling Stress Fracture
To set the record straight, none of the following information should be taken as known fact; but I am confident the following series of events is very close to how the medical team arrived at its final diagnosis for Carson Wentz. Here is a detailed look at the physician's thought process with attention to a clear understanding of exactly what a “stress injury” entails.
Week 7 - Carolina Panthers @ Philadelphia Eagles
Carson Wentz first appeared on the injury report with a back issue in Week 7. He likely either sustained a trauma from a hit or this gradually developed over time. It was reported by @LesBowen that Wentz previously had suffered a stress fracture in college per a report given to teams at the combine. It is very well possible even if the injury completely resolved it could have been re-aggravated at the present time. Here is when he likely would have complained about the soreness, tightness or pain in his back.
Imaging the Spine
At this point the medical staff obtained scans of the back to look for further injury. According to @RapSheet, Wentz had specifically undergone several CT scans which were inconclusive in regards to the injury. My speculation is this is probably not exactly what happened, at least not in this order.
Other reports by NBC Sports Philadelphia stated that "Eagles had been evaluating and monitoring Carson Wentz's back very closely over the last few months. They had done multiple MRIs and taken multiple images of his back. This confirms that Eagles medical staff did have MRI’s showing some kind of stress within the vertebra that was concerning". For medical folks following along this was the most confusing aspect of the reports, as an MRI is much more sensitive to detect injury in this type of situation. The MRI likely showed “stress” or inflammation within a certain part of the bone called the pars interacticularis (see below). An example MRI shows the typical findings of stress that the physicians would have seen (i.e. inflammation) in the bone.
Spine Model
Side View MRI Spine Showing Stress Injury
"Inconclusive Tests"
Basically, at this point the medical team would identify that this is the area of concern and investigate further. I believe this is where they likely would have obtained a special kind of CT scan to see if this area was merely inflammation or if there was an actual fracture through the bone. Here is where the tests were likely "inconclusive" showing no clear fracture of the spine. At this point, Wentz and the team would decide if he was physically able to play and willing to take the risk of further injuring the bone. Wentz obviously continued to play under close monitoring by medical staff where he was either having repeat CT scans or MRIs (reports vary) throughout the season. Eventually at some point during Week 14 one of the tests returned showing a conclusive fracture, which is also referred to as spondylolysis (see below).
3 Months Recovery, but probable for Sunday's Game
At this point reports confirmed that Carson Wentz had sustained a stress fracture to the spine and will not play Sunday against the LA Rams. At his press conference, Doug Pederson reports that "(Wentz) has a stress injury that has evolved over time and it likely will take 3 month to heal. However, he remained listed as probable for Sundays game, which recently has changed to questionable. My explanation behind the conflicting information is that Wentz could actually play if he was physically able to. These type of fractures have a prolonged course and many athletes with back pain may be playing without the knowledge that they actually have the injury. In Carson's case this comes with the risk of making the injury worse. On the other hand, the definitive treatment for a stress fracture (ie spondylolysis) is typically a combination of rest and physical therapy for 3 months. Therefore he actually could play if he was able to and wanted to take the risk, but definitive treatment is typically a full 3 months (or longer).
Key Questions to Consider
Is this fracture in the same location as the previous fracture sustained in college?
What level of the spine is the injury located? (Some areas experience less stress than others)
Is there any slippage of the fracture (spondyolisthesis)