Updated: Nov 18, 2022
Osgood-Schlatter Disease is a condition that causes pain in the front of the knee. It is extremely prevalent in people going through growth spurts. The largest growth spurts take place between 8-13 years for females and 10-15 years for males. Between the ages of 12 and 15 years old, it is estimated that 9.8% of people suffer from Osgood-Schlatter Disease. It is slightly more common in males with a prevalence of 11.4% compared to 8.3% of females. Interestingly, 20-30% of patients experience Osgood-Schlatter Disease in both legs according to a study by Smith and Varacallo.
Now that we understand how prevalent Osgood-Schlatter Disease is, it is important to understand what causes it. The quadriceps muscles come together to form the quadriceps tendon above your patella (kneecap). The quadriceps tendon attaches the quadriceps muscles to the top of your patella. The bottom of your patella is attached to your tibia via the patellar tendon. More specifically, your patellar tendon attaches to your tibial tuberosity, which is a small bump on the front of your tibia. This image below highlights the basic anatomy of the area.
The tibial tuberosity is very close to your growth plate. I discussed growth plates in a previous blog about Sever’s Disease, which is a similar condition except it affects the achilles tendon. Read more about Sever’s Disease here. To review, growth plates are located on the outer edges of long bones. They are a less dense part of the bone where growth occurs as we age. Eventually, the growth plates harden and become regular bones once you finish growing. Unfortunately, the nature of the growth plates makes them more susceptible to injury because of the less rigid structure.
Another important factor to consider is that bones grow first, then muscles. “Growing pains” are the result of tight muscles that are trying to keep up with rapidly growing bones. This is part of the reason that you are extremely inflexible during growth spurts. Your muscles are doing everything they can just to keep up with your bones, let alone allow you to touch your toes.
Your quadriceps muscles can become very tight during a growth spurt, leading to pulling on the patella via the quadriceps tendon. This upward pull stresses the patellar tendon that is attached to the tibial tuberosity, which is near your growth plate. The weakest point in your anatomy during this time is your growth plate, and the stress in the region can lead to inflammation and small fractures at the tibial tuberosity. This causes your muscles to tighten up more as a protective response, worsening the problem.
The inflammation due to the quadriceps muscle results in pain with activities that stretch the muscle or cause it to contract. Unfortunately, we contract our quadriceps to straighten our knees and stretch it to bend our knees. Loaded activities such as squatting can make the pain even worse because the forces are greater than if you lie down and bend your knee. The greatest forces occur with running and jumping. Many people begin to notice Osgood-Schlatter Disease while playing basketball due to the repetitive running and jumping.
Quadriceps tightness is also a hallmark sign of Osgood-Schlatter Disease. As I mentioned before, flexibility tends to be limited during growth spurts, but it will be worse in this case. Pain with knee bending is also an important sign. 20-30% of people have Osgood-Schlatter Disease in both knees, but everyone else will notice a significant difference in the pain and flexibility of one knee compared to the other. It is harder to diagnose Osgood-Schlatter Disease in patients with symptoms in both knees because they do not have a healthy knee to compare.
In some cases, swelling can occur at the site of the tibial tuberosity due to Osgood-Schlatter Disease. The swelling will worsen after activity and gradually subside with rest. It can be a result of chronic Osgood-Schlatter Disease, but I have seen patients with new pain demonstrate significant swelling as well.
Increased bone growth in the area is also a possibility. Our bodies respond to stress by creating more bone to resist the stress. Sometimes the tibial tuberosity grows to accommodate the tight patellar tendon, leading to a larger than normal bump on the front of your knee as pictured below. It is important to note that this bump can last even after symptoms resolve, but it should not be a concern if there is no pain or weakness present.
Diagnosis for Osgood-Schlatter Disease relies on patient history. Pain with the activities that I mentioned above is a good indicator along with considering the patient’s growth history. A recent growth spurt and pain in the front of your knee with exercise is typically Osgood-Schlatter Disease.
It is also important to figure out the exact location of the pain. There are many structures in the knee that need to be ruled out. One injury that appears similarly to Osgood-Schlatter Disease is Sinding-Larsen-Johansson Syndrome. Look at the image below regarding the primary difference between the two.
Both conditions involve the patellar tendon, but Osgood-Schlatter Disease refers to the bottom of the patellar tendon. Sinding-Larsseon-Johansson Syndrome involves the top of the patellar tendon. It includes stress to the growth plate on the patella itself. A medical provider should be able to feel the bottom of the patella and the tibial tuberosity to determine where the pain originates. Treatment for the two conditions does not differ tremendously, but an accurate diagnosis is preferrable.
Imaging for Osgood-Schlatter Disease is rare. X-rays may be taken to determine if an avulsion fracture has occurred. An avulsion fracture refers to the tibial tuberosity being pulled away from the tibia, creating a fracture. If this is present then there will be strict guidelines about limiting activity. Surgery is very rare because any damage to the growth plate can limit growth in the area and have a number of negative outcomes in the future. The image below shows an x-ray of an avulsion fracture due to Osgood-Schlatter Disease.
The first consideration with treating Osgood-Schlatter Disease is understanding the natural course. Eventually symptoms will resolve as your growth spurt ends and your muscles lengthen to catch up to your bones. Several options are available to improve symptoms and hasten healing, but you will eventually recover.
The primary intervention for Osgood-Schlatter Disease is load reduction. Simply limiting the number of jumps in a basketball player can help with healing. This is not a long term solution as the goal is to get back to basketball, but it can allow for decreased symptoms. A physical therapist should be able to take a look at your overall workload and make suggestions to minimally impact your competitive calendar. If you have extreme pain, then you may require an aggressive shutdown. However, minimal pain can lead to a slight reduction in activities before slowly ramping up.