Growing Pains: Osgood-Schlatter Disease

Adolescence is often a period of rapid growth for most children. Because bones grow faster than muscles, this growth can lead to tension from the tendons at their insertion on the bone, causing an apophysitis. One of the most difficult-to-treat conditions related to such growth is Osgood-Schlatter Disease (OSD), an apophysitis at the tibial tuberosity. Youth who play sports are more susceptible to this syndrome, especially those activities that emphasize knee loading such as basketball and volleyball.

The usual and customary treatment of OSD is a wait and see approach with the utilization of passive modalities such as stretching, ice, and heat. There’s very little research to guide intervention beyond this tactic. Therefore, researchers in Denmark sought to determine the effects of a different method in treating OSD⁽¹⁾. They enrolled 51 youth between the ages of 10 to 14 years old with a diagnosis of OSD into a prospective cohort study combining education with a more active treatment strategy.

By the time they enrolled in the study, the youngsters had suffered from the pain of OSD for 21 ± 12.5 months, on average⁽¹⁾. The intervention consisted of four visits with a physical therapist, at which both the child and their parents were present. The therapy was divided into two blocks. The first block focused on load management through decreased activity, education, and exercises that consisted of static holds. The second block progressed the exercises along a three-tiered ladder which ultimately led to a return to sport.

Follow up was at four, eight, 12, 26, and 52 weeks. The primary endpoint was at 12 weeks. The baseline and outcome measurements consisted of the pain on a numeric rating scale (NRS), the Knee injury and Osteoarthritis Outcome Score (KOOS), general physical activity, lower limb strength, and jumping performance. At the 12 week endpoint, the NRS score improved to two out of 10 as compared to seven out of 10 at baseline. All subsets of the KOOS showed improvement at 12 weeks with even fewer complaints of pain and increased function and quality of life at 52 weeks.

In regards to general activity, only 16% of the subjects returned to sport by 12 weeks. This number increased to 69% at 52 weeks. Knee extension and hip abduction strength, the focus of the exercise interventions, improved significantly by 12 weeks, as did the horizontal and vertical single-leg jumps. By the primary endpoint, 71% were very satisfied with their treatment results, however, 31% still suffered from discomfort at such a level that they would be very dissatisfied to live with that level of symptoms. This number resolved considerably by 52 weeks when only 5% were very unsatisfied with the thought of continuing in their current condition.

What does this study add?

Firstly, despite the anecdotal evidence of a fairly swift resolution of symptoms of OSD on their own (12 to 18 months), the youth included in this study had an average of  21 months prior history of pain. Considering that by the 52 week follow-up only 43% were very satisfied with their current level of symptoms, over half of the subjects had some sort of symptomology (pain or functional impairment) for three years running. That likely translates to a significant amount of time lost from sport.

In fact, by 12 weeks only 16% returned to sport. The authors suggest that since the sport and activity restrictions were based upon the progression through the exercise ladder, the study itself restricted athlete activity. However, it wasn’t necessarily that the athletes couldn’t progress to the next level because of their impairments. Perhaps they couldn’t progress because they didn’t actually do the exercises.

The compliance with the static hold exercise program was lacking in 25% of the subjects from the beginning of block one. Forty-three percent of the participants didn’t perform any exercises form the second exercise tier, while 75% of them didn’t make it to tier three. Whether this was a function of the disease or simply lack of compliance is unclear. Had the subjects been faithful to the program, there may have been a stronger return to sport cohort.

In addition, the program called for significant restrictions (guided by symptom response) on activity at the beginning to help decrease the constant load on the tibial tuberosity. However, the data from tracking devices worn prior to the study compared to the first-block timeframe showed a decrease of only 15 minutes per day of moderate to vigorous activity. So, were subjects still trying to engage in sport beyond their level of symptom tolerance? If so, did this repeated stress to the apophysis keep the disease flaring up and inhibiting progress? Curiously, the activity level decreased by 37 minutes per day by 12 weeks, meaning although many reported feeling better and able to do more by this time, they were less active.

This study, the first of its kind to investigate the response to activity modification, education, and exercise in athletes with OSD, reveals some important aspects of the disease and its management:

• OSD is not necessarily short-lived and self-correcting. Children may not simply out it, but may experience symptoms of pain and dysfunction for some time – significantly impacting their athletic career.
• Activity modification may be key to reducing symptoms, however, getting active kids to slow down is difficult. Clinicians may need to emphasize to parents the importance of activity restriction in the short term in the hopes of a safe return to sport sooner.
• An active exercise program can stave off muscle detraining from decreased time spent in sport. Specifically, a program targeted at the knee extensor and hip abductor muscles helps increase stability around the joints and improve performance as seen in horizontal and vertical jumps.
• A more frequent therapeutic intervention may help with compliance in this age group.

Reference

1. Orthop J Sports Med. 2020 Apr; 8(4): 2325967120911106.