The Dynasty Doctor: Adrian Peterson

Scott Peak

After the latest installment of the Dynasty Doctor, Eric B asked an excellent question on Adrian Peterson and his groin injury. “Is there reason to be concerned or not?”

Peterson missed the final two games of the 2013 fantasy football season with a groin injury that required surgery. The injury is being called a ‘sports hernia,’ although this is a bit of a misnomer. The source of pain isn’t like a typical hernia in the traditional sense, which is when a weakened inguinal region or abdominal wall has a bulging of bowels that can lead to significant pain. A sports hernia has pain in the groin region that can be present for several months, and is localized to the pubic region of the pelvis. The source of pain is often a torn tendon that is inflamed and hurts whenever powerful pelvic muscles contract. The pulling of these muscles irritates the inflamed tendon, and pain results. The basis of the injury is a tear in the tendon, usually from over-usage in athletes. Blood supply to the tendon is not ideal, and this tendon is at greater for injury.  Twisting or cutting movements can lead to the injury, such as Peterson’s daily routine as an NFL running back.

peterson

Take a look at the diagram above. The adductor longus muscle originates on the anterior pubic ramus of the pelvis, and it is at this location where tears can lead to inflammation and pain. If you can imagine the adductor longus pulling on the pelvic bone with a torn tendon, you can understand how painful it can be for an athlete. There are other strong muscles in the groin, such as the iliopsoas, adductor magnus, adductor brevis, gracilis and pectineus, so tearing of the adductor longus tendon doesn’t necessarily portend the end of an athlete’s career. Still, there can be weakness in the affected groin and that can result in imbalance between opposed abductor muscles, leading to future groin strains.

Peterson sustained the injury in November 2013 and continued to play through it. This is fairly typical, as athletes can often trace the approximate time or play where the injury occurred. The injury is not typically worsened with continued play, but it can be quite painful. Conservative therapy is usually tried first, but it may not be successful, and the injury can flare-up again, requiring surgery.

It has been reported that Peterson has undergone tendon release surgery, and this may be  from an adductor longus tendon tear. The surgery is referred to as an adductor tenotomy, and that is a fancy term used to describe a surgical approach where an incision is made in the tendon to either partially or completely removed it from the pelvic origin. As the inflamed tendon is removed from the pelvic bone, pain can be effectively reduced as the muscle will no longer be pulling on the injured tendon.

Results from this surgery are generally good, but the literature is not ideal and outcomes are variable. Return to previous sports activity levels after an adductor tenotomy are reported to be 54% to 98%, depending on whose data you believe. Time for recovery and rehabilitation ranges from 2 to 4 months. Improvement in pain is quite good, with 70-90% of athletes reporting a reduction in pain and generally good to excellent outcomes.

Notably, Peterson had surgery for a sports hernia surgery in 2012, and this will be his second surgery for this injury. It’s not unusual for both the left and right groin to have the same injury and an adductor tenotomy on both sides.

I think there is an excellent chance for Peterson to return to play in 2014, so in that sense, I’m not overly concerned about the injury. There is a chance this injury could reduce his superior athletic performance, but we’ve learned that underestimating Peterson’s resolve is not a good idea. Notably, the Minnesota Vikings hired Norv Turner as their offensive coordinator and that bodes very well for Peterson’s chances in 2014.

In terms of dynasty value, I would favor selling him now. I often hear Peterson referred to as a “god” or invincible, but that’s based mostly on human emotion and is more hyperbole than anything. I advocated selling Peterson last year and I haven’t changed my opinion on him. After his massively successful 2012 season, rebounding from ACL rupture, I advocated selling him at his high valuation. I saw Peterson go 1.01 in real dynasty start-up drafts, not just mocks, and this despite data to show running backs often start declining around age 27. Austin Lee of Pro Football Focus wrote an excellent article called Age of Decline: Running Backs, and his data shows a decline at age 27 for running backs, a plateau from age 30-32, then a steep fall-off in production.

Peterson will be 29 next season. In the best of circumstances, he could be more like Emmitt Smith, who still remained productive until age 31, or Frank Gore, who still produced solid numbers at age 30. We also can’t ignore the injury factor, as Peterson has required surgery the last three off-seasons, including this year. Peterson has a total of 2,241 career touches. As a comparison, Steven Jackson has 2,992, Frank Gore has 2,520, Maurice Jones-Drew has 2,139 and Ray Rice has 1,800. Peterson is 751 touches away from Jackson, and he would reach this number in just over two seasons, given he has averaged 320 total touches per season. Peterson has already exceeded the total touches for Ray Rice and Maurice Jones-Drew, both of which are showing signs of decline. Peterson might be a god in NFL terms, but he’s still human. I believe Peterson’s best possible scenario is a top 12 running back for fantasy the next two years, but it’s hard to envision a scenario where he maintains that level of production beyond. Of course, it’s also possible his decline is imminent.

I would advocate selling Peterson if near-value can be had in a trade. It’s not impossible, as Ryan McDowell’s recent article shows Peterson has an ADP20. Younger options with similar ADP values include Keenan Allen and Cordarrelle Patterson. I think Patterson could be in line for a huge uptick in production under Norv Turner, similar to Josh Gordon last year and I would consider trading Peterson in a deal for Patterson or Allen in dynasty leagues. Peterson should still have top 10 value in re-draft leagues for 2014, but his dynasty owners may want to consider exiting their position in him while he still has second-round start-up value.

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