Apr 1, 2015Lasting Effects
With each traumatic joint injury suffered, an athlete’s risk of developing osteoarthritis rises. Early intervention is key to keeping the disabling condition at bay.
The following article appears in the March 2015 issue of Training & Conditioning.
What do building flood levees, instituting seatbelt laws, and educating athletes about the risks of osteoarthritis (OA) have in common? Each highlights a prevention strategy aimed at minimizing the damage of a traumatic incident.
The need for prevention is often seen in hindsight. A hurricane’s destruction brings the need for levees into sharp focus. Seatbelt laws were imposed only after thousands of car accident fatalities. While OA doesn’t cause the same type of devastation, it can have lasting effects, such as chronic pain, loss of movement and function, and limitations in daily life.
Prevention strategies for OA are often neglected, but alarming research over the past decade has stressed their necessity. Studies suggest that one-third of athletes who sustain an ACL tear and reconstruction will develop knee OA within 10 years. Half will develop knee OA in 20 years.
While athletic trainers’ main focus is on preventing and rehabbing the injuries of today, we also have a responsibility to help decrease the occurrence of disabling conditions associated with these injuries in the years to come.
The good news is, prevention strategies for OA exist. They start with athletic trainers understanding how a traumatic joint injury may impact an athlete’s future health and factors that may contribute to OA. Then, by implementing evidence-based strategies after an injury occurs, athletic trainers can improve athletes’ overall long-term prognosis.
FACTORS TO CONSIDER
The progression of OA can be accelerated following an acute traumatic joint injury, fracture, or surgery. Referred to as post-traumatic OA, this scenario accounts for 12 percent of all cases. Every joint in the body is susceptible to developing OA, but lower-extremity joints are associated with more frequent long-term disability.
There are a host of risk factors that likely contribute to the joint deterioration that leads to OA. Some can’t be changed, such as genetics, sex, and age. But others can be altered following injury, like joint loading, neuromuscular function, and bodyweight. Once a joint has been compromised, it is critical for athletic trainers to monitor these risk factors and watch for changes that could hasten the progression from acute joint injury to post-traumatic OA.
Joint Loading: Changes in mechanics occur following most joint trauma, and they are often noticeable during injury. For example, immediately after an acute lower-extremity joint injury or surgery, patients adjust their walking gait due to pain, restricted range of motion, and the diminished muscle function that accompanies swelling.
These slight changes in movement mechanics can persist long after recovery and may not be resolved when the athlete returns to activity, thus creating lasting alternate loading patterns within the injured joint. Aberrant joint loading causes stress to the surrounding tissues, which may accelerate the joint’s degeneration, leading to further injury and possibly OA.
Three other consequences of traumatic joint injury–ligamentous laxity, changes in bone structure, and neuromuscular insufficiency–may also cause altered joint loading. When the athlete compensates for changes in joint stability following injury, the adjustment further shifts loads and leads to additional distortion in laxity, bone structure, and neuromuscular control. This could develop into a vicious cycle that athletic trainers must break during the rehabilitation process.
Neuromuscular Function: Inhibition of the musculature surrounding a joint is common following injury and/or surgery. For example, neuromuscular quadricep inhibition is common following knee injuries. While this is likely a protective mechanism to minimize potentially dangerous forces created by strong muscle contractions around a healing joint, it can cause long-term problems.
When a muscle is inhibited, it does not contract properly. Persistent muscle inhibition may decrease performance, increase an athlete’s risk of future acute injuries, and alter compressive forces in joints during weight bearing. Altered joint load may lead to chronic injury to the joint structure and post-traumatic OA development.
Bodyweight: Maintaining a healthy weight following an acute traumatic joint injury is not only important for return to play, but it is also critical in managing the risk of post-traumatic OA. Increased body mass in addition to decreased muscle function may be a hazardous combination following lower-extremity injury. Because the musculature’s ability to handle loads at the joint is compromised, compressive forces are magnified.
For most athletes, the goal of post-injury rehabilitation is to return to play as soon as possible. In their rush to get back to competition, however, few will think of their future beyond athletics. This is where athletic trainers can make a difference. The impact that a single acute traumatic joint injury can have on an athlete’s future health cannot be ignored during recovery. Clinicians should utilize treatment interventions and take the time to educate the athlete on OA risks.
Following a traumatic joint injury, there are no universally accepted guidelines for predicting long-term outcomes. But there are a lot of proactive steps athletic trainers can take to get athletes on the right path.
A good place to start is with an individualized post-injury program focused on maintaining the improvements made in strength, neuromuscular control, and movement during formal rehabilitation. Take-home regimens that focus on continued strengthening, weight management, and movement mechanics can also prove beneficial.
In addition, athletic trainers can deploy treatment strategies that encourage proper loading of the injured joint, which will reduce the risk of secondary damage and recurrent injuries. Strategies include feedback-related interventions that incorporate correct movements for gait and jump landings. Improving overall strength activation may also transfer to greater function in many tasks.
At the beginning of the athlete’s rehab, promoting healthy activity choices is a must. The athlete should be advised to limit excessive or repetitive weight-bearing loads and focus on low-impact aerobic exercise and strength training. When progressing to sport-specific tasks, athletic trainers should make sure the athlete incorporates proper movement patterns. A little caution early on can go a long way in preventing OA down the line.
When athletes prepare to return to play following an acute joint injury, many athletic trainers will turn their attention to developing symmetrical strength, range of motion, and neuromuscular control between the injured and uninjured limbs. Especially for lower-extremity joints, care should be taken to minimize side-to-side deficits when developing symmetry.
Although athletes often return to participation with low strength imbalances (less than 15 percent of the contralateral side) or slightly inefficient movements, the long-term consequences of this practice on joint health are unknown. For example, while a five percent side-to-side quadriceps strength deficit following ACL reconstruction may seem insignificant, a five percent deficit in the quadriceps’ capacity to absorb energy while walking may have significant long-term consequences on joint health and progression to OA.
Common modalities used to decrease side-to-side deficits include transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, cryotherapy, or manual therapy in conjunction with rehabilitation. Addressing neuromuscular inhibition with these treatments may also be a way to improve persistent muscle weakness and develop proper movement patterns.
When trying to obtain symmetry, it’s important to note that strength and neuromuscular deficits may occur bilaterally following a unilateral joint injury. Because of this, clinicians should make sure that achieving symmetry does not come at the expense of decreased strength of the uninvolved limb.
Athletes might perceive returning to play as the end of their rehabilitation, but it is important for athletic trainers to continue to plan for the long-term. Players may require regular checkups to ensure proper muscle strength, neuromuscular control, and movement mechanics have been maintained.
In many cases, getting sport and strength and conditioning coaches involved can help in monitoring an athlete’s long-term progress. Strength coaches may notice deficits or aberrant movement patterns during a training program, and sport coaches may observe concerning patterns during practices or competitions.
Finally, educate athletes, coaches, and parents about the risk of OA following an acute traumatic joint injury, even if the player returns to play without further complications. Athletic trainers should explain that OA is a chronic disease that develops even though symptoms may take years to manifest. It is also worthwhile to describe how the joint disease progresses and what symptoms of OA feel like, which may allow for earlier recognition and treatment.
Athletes should be encouraged to incorporate strategies to manage their joint health for the rest of their lives, such as a daily strengthening and stretching program and maintaining a healthy weight. Annual monitoring of joint health using established and validated patient-reported outcomes may also be appropriate.
ON THE HORIZON
Fortunately, understanding the pathogenesis of post-traumatic OA has become a priority for many clinicians and researchers. Active areas of study include evaluating new imaging and fluid-based biomarkers that can detect changes in cartilage metabolism and joint health within the initial months following joint injury and surgery. These markers may also help identify the early benefits of new treatments. And multiple groups are trying to better understand the role that movement mechanics, neuromuscular control, and tissue metabolism have on the progression of post-traumatic OA.
But we still have much to learn. Clinical studies need to be completed to determine the best rehabilitation programs, return-to-participation criteria, and biomechanical interventions following specific joint pathologies. It is critical to develop strategies that would allow clinicians to follow patients after discharge from formal therapy in order to periodically evaluate them for changes in joint health that may represent the progression of post-traumatic OA. This would provide earlier opportunities to intervene and alter the trajectory of OA.
For now, athletic trainers can utilize a treatment approach that strives for both short-term safety regarding return to play and long-term OA prevention. There is no cure for OA, but in a setting where athletes, parents, and coaches are often focused on today, athletic trainers must be the ones thinking about tomorrow.
SIDEBAR: BEING PROACTIVE
One of the best ways to prevent post-traumatic osteoarthritis is to minimize the risk of sustaining a joint injury in the first place. There is evidence that formalized injury prevention programs can reduce the incidence of acute lower-extremity injuries by up to 40 percent.
When developing an injury prevention plan, here are a few critical components to include:
• Assess movement mechanics during pre-participation examinations to determine if athletes are moving poorly.
• Target high-risk movement patterns that have been associated with the risk of acute traumatic joint injuries, such as poor jump-landing mechanics.
• Target each player’s limitations in range of motion, strength, and neuromuscular control.
• Monitor feedback and movement training to improve the athlete’s acquisition and retention of novel motor skills.
• Augment movement feedback with strengthening techniques to provide athletes with the functional capacity to perform sport-specific movements correctly.
SIDEBAR: WHEN TO RETIRE
Sports medicine professionals must be prepared to have difficult conversations with athletes, parents, and coaches about the real impact that multiple joint injuries may have on future health and well-being. In some cases, this means discussing an early retirement from their sport to prevent the development of post-traumatic osteoarthritis (OA). Here are a few tips on how to frame your message.
• Remind the player that they will spend more years of their life as a nonathlete than they will as a competitive athlete. The ability to move without pain and disability in the future is important for engaging in daily life
• Explain that a history of joint injuries increases the risk of developing post-traumatic OA. Injured athletes may not link a single traumatic knee joint injury with the rapid onset of OA. They may see surgical ligament reconstruction and rehabilitation as an all-encompassing curative procedure. Although it improves immediate function, no current surgical or rehabilitative efforts can lower the risk of early-onset OA.
• Provide athletes with ways they can continue to be part of their sport. This solution allows them to make a health-conscious decision to decrease risk of reinjury while maintaining their identity within their sport. Who knows, these athletes may become future health care professionals who will seek to treat joint injury in the next generation of athletes.
• Refer to established policies and procedures when necessary. It is important to remember that the chance of developing OA will not deter many athletes from their sport following multiple joint injuries. Similar to guidelines established for athletes sustaining multiple concussions, sports medicine teams may look to predetermined protocols to disqualify athletes from engaging in high-risk sports following multiple traumatic injuries.