When I started writing this, I thought a “sports hernia” was a type of pelvic floor injury which can lead to a true hernia. That type of injury is a sports hernia, but sports hernia is typically used more generally. Medically, a hernia is when stuff (medical term) gets out of where it is supposed to be contained and bulges into somewhere is is not supposed to be. For example, take an inguinal hernia (please!). The inguinal canal is a natural, necessary passage way in the body. An inguinal hernia happens when the passage way gets stretched out and stuff (mostly fat but potentially intestines if the hole is big enough) gets down where it is not supposed to be. An inguinal hernia is fixed by tightening the opening of the passage or covering it with surgical mesh. A herniated disk in your back happens when the anulus fibrosus of the disc tears and the nucleus pulposus bulges out. Tear a hole in a donut and the jelly oozes out.
So what's a sports hernia?
A “sports hernia” is not necessarily a hernia. The American Academy of Orthopedic Surgeons says “A sports hernia is a strain or tear of any soft tissue (muscle, tendon, ligament) in the lower abdomen or groin area.” They also say “the medical community prefers the term "athletic pubalgia" to refer to this type of injury.”
The most common injuries occur to the abdominal oblique muscles or to the adductor muscles of the thigh (the adductor muscles pull the thigh toward the mid-line). Muscles attach to bones via tendons. In these injuries, the tendon can tear or the tendon can pull off the bone (an "avulsion" injury).
When an athlete is trying to move his leg one direction and force is being applied in the opposite direction this type of injury can occur. A goalie doing the splits to make a save is a common cause of sports hernia. The skating stride puts a lot of strain on the adductor muscles. Being hit from the side at the wrong moment in the skating stride seems to be the cause of Shattenkirk's injury.
While physical exam is helpful, MRI is the best diagnostic tool. MRI will show the injury (or injuries) and help with planning treatment.
Conservative treatment with pain medicines, steroid injections, physical therapy can be used. Often surgery is necessary. The Vincera Institute says there are 121 different possible surgeries. If tendons are torn they are repaired. If there are avulsion injuries, the tendons are sewn to the bones.
Typically, players are back on their feet the day after surgery. Physical therapy starts soon after surgery as does massage therapy. Depending on the surgery, recovery and return to competition usually takes 4 to 8 weeks.