the “science” of return to play

Monday, December 30, 2013

New Year resolutions tend to be ignored or forgotten within weeks if not days, but perhaps sports reporters might help their readers remember that their team’s favorite player is a real person, whose body can be damaged and will take time to heal. Physiology cannot be rushed, and those who write the stories in 2014 need to stress that fact. Looking back at 2013, there are lessons to be learned about torn ligaments, broken bones and broken brains.

Concussions make headlines every week in the NFL. The standard play-by-play commentary is that the player has been taken to the locker room to be tested for a concussion. Let us be frank: there is no one test that can confirm the presence or absence of a concussion. The diagnosis is made based upon history. Was there a thought process or cognition issue? This can range from being knocked unconscious to being minimally confused, so minimally in fact, that the player may not recognize the symptoms. Over a period of time, new symptoms may arise from headache, nausea, vomiting, light and sound sensitivity and difficulty concentrating. To be considered a minor head injury, the neurologic exam needs to be normal, so the diagnosis is made based on the player confessing that all is not right and that may not be evident for hours or days.

Once the diagnosis is made, the next question becomes, when is it safe to return to play? This is a question that stumps the experts and the most recent consensus statement on concussion in sport gives cautious guidance. The conclusions of the meeting held in Zurich in November 2012 were published in the spring of 2013 and reminded physicians and trainers that there was no one test or group of tests that can determine when the brain has completely healed. Physical and mental rest are the cornerstone for treatment but for how long has yet to be determined. The goal is to have a healed, normally functioning brain that can withstand the next concussion without leaving devastation. The researchers stressed that children and adolescents needed more time to recover and should be handled more gently. As for the elite athlete, there is no dispensation for being a pro. The return to play guidelines are not to be bent for the star quarterback.

The rules for how the body repairs fractured bones also do not change for the star quarterback. Aaron Rodgers took 7 weeks to return from a broken collarbone to lead the Packers into the playoffs. He threw the winning touchdown to Randall Cobb who took 10 weeks to recover from a broken leg. As it turns out, neither broken bone is likely completely normal, but they had healed enough to function and to withstand the risk of spontaneously breaking. Bones take time to heal and the process is the same. Blot clots, granulation tissue and fibroblasts form a bridge that connect the two broken edges of bone. Chondroblasts move in to form a cartilage matrix that allow osteoblasts to lay down calcium and bone cells. This bone is laid down randomly and allows the edges to bridge and become stable. The final remodeling allows the bone to be sculpted, returning it to its normal tensile strength. That final process takes months but for most people, return to work or play occurs in just few weeks.

The Rodgers saga was a week to week soap opera with x-rays and CT scans trying to determine when the bone was stable enough for him to play. As it turns out, there is no specific test that can make that determination. Doctors provide a best guess based upon hoe a bone looks but that test doesn’t measure how strong that bone might be. It is also important to remember that the initial injury occurred when a normal bone was stressed and broke because of a tackle. If the same circumstances were to occur, the bone would potentially break again regardless of how well it had healed.

The news about ligaments centered around Adrian Peterson and his “miraculous” comeback to play in the NFL just 6 months after tearing his ACL. This set the presumptive standard and fans were upset that Derrick Rose of the Chicago Bulls took a year to return. Those same NBA fans were more upset that perhaps Kobe Bryant came back too quickly from an Achilles tendon injury and should not have been playing. Ligaments heal similarly to bones except that calcium is not laid down in the final healing process. That rate of healing depends upon where the injury occurred, what repair was required, and the anatomy of blood flow. Some parts of ligaments, tendons and cartilage have great blood supply and heal quickly but other areas that aren’t so blessed and need more time. Once the anatomy has healed, physiology has to be repaired. Physical therapy and rehabilitation returns range of motion and muscle strength and only when those are maximized can the player consider returning to practice. There is one final part that needs fixing and that is proprioception. The player’s brain needs to figure out where the injured part is in relation to the world and to subconsciously trust the bone or joint to move instinctively when asked to perform. Peterson’s return from ACL repair was abnormally quick, Mr. Rose’s was a little longer, but both were normal for them.

As the New Year approaches, the gift it can provide to a sports fan is patience.  For most injuries, there is more art than science in deciding when it is the right time to return to play. The obligation of the sports writer is to remind their readers that the players on the field are real and subject to the laws of physics and physiology, no matter how unreal they perform on game day.

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