What is an apophysis? An apophysis is a growth plate that provides a point for a muscle to attach.
What is apophysitis? Apophysitis is due to chronic traction of a tendon at its origin or insertion. The growth cartilage of the apophysis is the weak link in the muscle-tendon unit, and is prone to injury from repetitive activity. Continuous stress at the apophyseal site leads to local swelling and pain. It is most common in kids in elementary to high school age (when they start playing sports).
What are the most common sites of apophysitis? The knee is the most common site of apophysitis in kids and is otherwise known as Osgood-Schlatter’s disease. Other common sites are the heel (Sever’s disease), the lower part of the kneecap (Sinding-Larsen-Johansson disease), the outer side of the foot (Iselin’s disease), and the elbow (Little League elbow). There are also several places on the pelvis where muscles attach, so apophysitis can occur in a handful of sites. Soccer players, runners, and sprinters are especially prone to developing apophysitis in the pelvis (which usually presents as hip or groin pain).
How are specific types of apophysitis treated? All types of apophysitis are treated with activity modification (rest!), anti-inflammatories (like ibuprofen), ice, and potentially physical therapy depending on the severity. Children with Osgood-Schlatter’s disease may benefit from a knee strap or knee pad depending on the sport, children with Sever’s disease can be treated with heel cups, and children with Iselin’s disease can be treated with a lace-up ankle brace or lateral heel wedge.
Is there a way to prevent apophysitis from happening? Just like any overuse injury, it can be prevented with appropriate rest from activity, stretching, and using the right equipment for the specific sport. However, some kids are more prone to developing apophysitis based on such things like muscle weakness or imbalance, and his or her running gait. Such things can be evaluated and treated with physical therapy.
It is not always easy to determine how long it takes for a type of apophysitis to completely resolve. Some kids can heal in a few days while others can take weeks to months (even with the appropriate treatment). Rest and activity modification is key to helping apophysitis resolve more quickly.
Rachel Brewer, MD