What is a microdiscectomy, and what does it mean for Andy Dirks?

The recent news that left fielder Andy Dirks will require back surgery and miss approximately three months of the upcoming season has, understandably, thrown the Tigers' fanbase into a frenzy. Unlike some injuries -- Jose Iglesias' shin splints, for instance -- everyone saw the term "back surgery" and appropriately lost their minds. Any type of back surgery is serious business, and the risks associated with working in close proximity to the spinal cord are much higher than your run-of-the-mill knee arthroscopic procedure.

Specifically, Dirks is set to undergo a microdiscectomy, which was aptly described by MLB.com's Jason Beck yesterday.

As Ausmus explained it, a fragment of the disk between Dirks' L4 and L5 vertebrae tore away from the rest of the disk, so that piece must be removed to alleviate the pain. The operation will be performed by Dr. Thomas Tolli in St. Petersburg, Fla.

For those unaware of the anatomy and biomechanics of the spine, the L4 and L5 vertebrae are the lowermost spinal bones in your back. A practical example: put your hands on your hips, work your way around to your back, and you're right around L5. There are discs that sit between each vertebrae in the spine. They act as a shock absorber for the body, and begin to break down by the time we are in our early 20s. In Dirks' case, it appears that a piece of that disc is no longer attached to the rest of it, and is hitting something in his lower back, causing pain. That pain can be anything from localized soreness to a sharp pain shooting down his entire leg.

The procedure sounds simple, and it can be. In a textbook case, the surgeon will make a small incision, use his surgeon tools to remove the small piece of disc that has been dislodged, and sew the person back together. All in all, maybe an hour of handiwork. Given Dirks' high level of performance prior to the operation, the recovery period is fairly quick. This is the 12 week estimate that we have seen thrown around in the media so far.

Unfortunately, things are not always so simple. Depending on how far that piece of disc has migrated, the surgeon may need to make a bigger incision, remove a piece of bone, or clean up other parts of the spinal canal. Any complications will considerably lengthen Dirks' timetable for return, especially if that piece of disc has impinged on a nerve exiting the spinal canal. If Dirks has experienced any numbness or tingling in one of his lower extremities, the recovery period can be longer as the impinged nerve regains function.

Given that we have heard next-to-nothing about Dirks' previous history of lower back problems, I would imagine that the current timetable for his recovery will be fairly accurate. The team will not rush his return, but as long as things go according to plan, he should return to action before the All-Star Break.