Okay, so maybe the Dallas Stars haven't gotten a Groupon for arthroscopic hip surgery (buy four, get the fifth free!), but there's no doubt the team has sent more than the average number of players under the knife in the past 14 months.

Valeri Nichushkin. Ales Hemsky. Trevor Daley. Both John Klingberg and Jamie Benn got the extra fun of having not just one but both hips done in relatively short order.

What the heck is going on with the Stars hips that they need so much maintenance all of a sudden? It's a combination of improved arthroscopic techniques and a better understanding of how minor anatomical changes can lead to big-time problems.

Mike Heika wrote a fabulous article where he chatted with Stars trainer Dave Zeis about the organizational philosophy regarding these hip injuries. if you haven't read that yet, I highly recommend it.

Here's the crux of the Stars new approach:

"They are starting to figure out a correlation between FAI, sports hernias, groin pain and labral tears. That’s kind of where it brings us now," said Dave Zeis, head athletic trainer for the Stars. "Now, we know we have these bony build-ups, which you can see on X-Rays and CT scans and MRIs, and those lead to labral tears, so what is going on and what is leading to the problems?" The problem is that neither the athlete nor the athletic trainer can tell when things will intensify. Benn played through some very difficult pain in the middle of the season and then saw things get better as the season went on. So should the Stars simply give him rest over the summer and hope it will be better next year or should Benn have the surgery now, go through a recovery, and then be fully healthy next season? The Stars are choosing to take care of any FAI situations they can now.

To better understand what Zeis is talking about and how that plays into the larger picture of hip functionality, a good understanding on how bones grow and how the hip joint works are helpful. Essentially, what the heck is femoroacetabular impingement, and why are so many of the Stars potentially at risk for it?

To translate from medical to English, the acetabulum is the socket on the hip joint that the head of the femur sits in, and impingement means some sort of rubbing or pressure that can inhibit smooth movement. So FAI is some sort of non-ideal movement within the hip that can lead to things like osteoarthritis or other long-term consequences.

The precise mechanism that causes FAI is not specified in most patient-facing literature, but it's important to know that bone is not static, even as an adult.

From a functional perspective, humans store about 99 percent of their calcium (which is important for muscle contraction) in their bones, and there are cells that do nothing but break apart bone to put calcium into the blood and others that do nothing but form new bone from excess calcium. Because of this, bone can grow unevenly, particularly in areas of stress. On a simple level, orthodontic braces work because of this mechanism - the wires pull the teeth and the roots press against the bony tooth sockets, causing remodeling where those sockets move into a straighter position.

Bones grow more when a person is a child and adolescent, meaning stresses from things like repeated hip flexion and extension (think a hockey stride) could theoretically cause more stress on some areas and lead to bone remodeling. This growth can lead to things like bone spurs, which are bony projections, and those bone spurs can damage the cartilage around the joint.

That brings us to the second important piece of background information - the role of cartilage in the hip joints. All of bones involved in the big joints of the body are covered by a thin layer of articular cartilage that provides a smooth surface for unhindered movement. In addition to this cartilage, the big sockets in the body (the glenoid cavity in the scapula and the acetabulum in the pelvis) have another, thicker layer of cartilage called a labrum that runs along the rim of the socket to provide a suction seal to the ball of the joint as well as add additional stability.

Cartilage is great at absorbing shock and providing smooth surfaces but terrible at taking wear and tear from rough or sharp parts of bone, mostly because it has no direct blood supply and cannot heal minor injuries efficiently like other tissues. Because of that, things like bone spurs or other overgrowth can tear up the cartilage in a joint and cause problems like osteoarthritis or other painful, range-of-motion-limiting disorders.

Which all takes us back to FAI, where the bone has overgrown in some way (sometimes on the ball of the femur, other times on the socket of the pelvis) that is causing unnatural wear on the cartilage, be that articular, labrum or both. Hard use, like being a professional athlete, would make this wear-type injury progress faster and be more painful than it would in a person who sits at a desk all day.

The pain may be hard to place, and that's why research is indicating thing that were previously diagnosed as chronic groin strains may have actually been related to FAI. Additionally, pain and range-of-motion problems caused by FAI are now being blamed for other issues, such as sports hernias.

So how do you fix FAI if it can be so problematic? Like most joint injuries, there's the conservative way and the more invasive way. First-line treatments include rest, physical therapy and anti-inflammatories, often via direct injection. If that doesn't work, surgery is definitely under consideration.

They used to do orthopedic work on the hip via "hip dislocation and open osteochondroplasty" which is the shaving and reshaping of the bones after reaching them in exactly the way it says on the tin. This, understandably, had a long recovery period and high rate of complications. More recently, arthroscopic technique has advanced to the point that most patients can avoid the whole "doctors pop out your hip" bit and instead have cameras and small tools inserted through tiny incisions into the joint without major incisions.

If you're curious and like surgery videos like me, a video of what goes on inside can be found here. As all of this is shot inside the articular capsule, it is not particularly gory. A full video including what the arthroscopy looks like from the outside is here. It's also not gory, but you can see all the insertions and a small amount of blood and fluid (mostly saline), so be aware.

This is not a totally new surgery to hockey. It's been around long enough for papers to have been published both on the recovery from surgery and certain types of bone overgrowth appearing more in high-level players. But in the world of medical science, it's definitely on the greener end of the spectrum.

What this all adds up to is we may be seeing a lot more of this type of surgery in the future if it's successful in preventing players from dealing with year after year of groin pulls or sports hernia injuries, not to mention preserving cartilage in the hip for life after the professional career is done. The Stars seem to be one of the first teams fully on the bandwagon on using the relatively major surgery as a step toward preventing long-term issues, but they certainly won't be alone when all is said and done.