Chad is a tall, thin and healthy 13 year old who has become quite an athlete. He excels in soccer and basketball, and has even run a 10-K with his father and turned in a respectable time for his age. Looking over his chart, I notice that over the past 5 years, he has only been in the office for his yearly physicals...not even a cold or a sore throat.
Today, however, Chad is in the office because of persistent knee pain. It started "months" ago during soccer season. His right knee became tender and painful and it really bothered him to run on it. He took some ibuprofen (prescribed by his runner-father) but this didn't help much. As the condition was not getting any better, mom intervened and made the appointment. She later confided to me that she was worried that he may have a tumor or cancer.
Chad denied having any fevers, weight loss or rash, and the exam of his knees revealed excellent range of motion and very stable joints. Just below the right kneecap there was a prominent swelling of the tibial tubercle (fig. 1) which was very tender. For completeness, a thorough exam of the hips was done and this too, proved to be normal. Knee pain in children and adolescents can be the presenting symptom of hip problems. The pain is referred from the hips to the knees.
After examining Chad, I was sure that he did not have arthritis, cancer or a tumor, or hip problems. He had Osgood- Schlatter disease (OSD) which is as relatively common condition in adolescents. It is particularly prevalent in athletic individuals. OSD is a disturbance of the patellar tendon where it inserts, or attaches, on the tibial tubercle of the lower leg (fig. 1). The exact cause is not known however it is felt to be due to repetitive overuse of the cartilaginous-bony structure of the tibia at the tubercle. This is probably why it is seen in children who are involved in sports and activities which involve jumping, cutting or stop and go movements such as football, soccer, volleyball and basketball.
OSD usually develops in girls between 8-13 years of age, and in boys between 10-15...this coincides with the start of their growth spurt. One paper reported the incidence of OSD to be 20% in athletic adolescents, compared to 5% in non-athletes.
This condition is a benign and self-resolving disorder that usually takes 12-24 months to run its course. Once a diagnosis of OSD has been made, it is rare for x-rays or MRI's to be needed. In most cases of OSD, the pain is bothersome and a nuisance, but rarely is it debilitating or restrictive. Most flare-ups of OSD can be managed with ice for 20 minutes after exercise, anti-inflammatory agents, and short rest periods to let the inflammation subside. Shock-absorbent insoles can be of benefit as are stretching exercises to loosen the hamstring and quadriceps muscles. Running on asphalt or cement should be limited as much as possible.
A brace is available for OSD and it is worn just below the kneecap directly over the patellar tubercle. This brace takes the pressure off of the tubercle and can give tremendous relief (fig. 2).
More severe cases of OSD can occur although they are rare. In a few instances, the traditional measures discussed above do not help and normal daily activities are unbearable. In these cases, a 3-4 week period of immobilization with a knee brace or a cast might be warranted. If so, this should be followed by a closely monitored regimen of physical therapy and rehab.
Chad's mom was relieved with this diagnosis as was Chad. He carefully followed our plan and did wear the brace. Over the next year, he did experience periodic "flare-ups" but none of which kept him out of sports. By the end of the year, the OSD had pretty much run its course and it was no longer a bother to him.