The anterior cruciate ligament (ACL) is a band of strong connective tissue in the knee, connecting…
What is Osgood-Schlatter disease?
Osgood-Schlatter disease is a condition that can cause pain in the knees of children and adolescents. It is often associated with a growth spurt and usually gets better with simple treatment.
The condition most often affects children aged 9-14 years. It is more common in children who are very physically active, particularly when activities involve a lot of running and jumping, such as football, gymnastics, cricket, basketball and ballet.
While the affected knee can be painful and may require a temporary slowdown of sporting pursuits, the good news is that children with Osgood-Schlatter disease can generally continue to be active, as the condition will gradually settle with time, when the bones stop growing.
The patellar tendon is important in movement of the knee. The tendon connects the quadriceps muscle in the front of the thigh to the tibia (shinbone) at a point just below the kneecap. This attachment point normally forms a small lump or protuberance that is known as the tibial tuberosity.
When the quadriceps muscle contracts, the knee straightens. If the patellar tendon becomes too tight, it can pull on the tibial tuberosity. This can cause:
- Pain and inflammation at the point where the tendon attaches to the bone, and;
- Tiny micro-fractures in the bone, which can lead to growth of new bone tissue and enlargement of the tuberosity.
- During a growth spurt, the growth of the patellar tendon does not keep up with that of the lower leg, causing the tendon to be tight;
- A child participates in sports or activities that put tension on the tendon, particularly those with a lot of running and jumping, and;
- There are misalignments of the legs, such as being knock-kneed or flat-footed, which can put extra tension on the tendon.
Boys have historically been more likely to experience symptoms; however, this may be because they have tended to be more physically active than girls. Because the growth spurt that coincides with puberty tends to happen a little earlier in girls, they are more likely to have symptoms at a slightly younger age (around 11-12 years of age) compared to boys (around 13-14).
Signs and symptoms
Osgood-Schlatter disease may affect one knee or both. When both knees are involved, one is often worse than the other.
Osgood-Schlatter disease is suspected when pain in the knee tends to:
- Occur when the knee is straightened, such as in kicking;
- Occur with squatting or kneeling;
- Occur when running, climbing, jumping or going up or down stairs, and;
- Reduce with rest.
Other symptoms include:
- A swollen bump on the front of the shinbone (tibia) just below the kneecap, and;
- Redness and inflammation of the skin over the affected area.
Methods for diagnosis
Osgood-Schlatter disease can usually be diagnosed by a doctor from a physical examination.
They will examine the affected knee and look for tenderness and may ask the child to move, squat, or straighten the knee against resistance, to see if this causes pain.
X-rays may be recommended, but are often not necessary to diagnose Osgood-Schlatter disease. Other tests may be recommended if the cause of the symptoms is unclear and other conditions need to be ruled out.
Types of treatment
In general, symptoms will disappear once the growth of the bone stops. This can take months to a year or two.
To manage the symptoms, the following can be helpful:
- Mild pain-relief medications such as ibuprofen and paracetamol;
- Icepacks on the knee to reduce swelling and pain;
- Physiotherapy - stretches and exercises that help to lengthen and strengthen the quadriceps, hamstrings and calf muscles may help to reduce tension on the patellar tendon;
- Reducing the amount of high-impact sports that trigger the pain - complete rest is generally not recommended, but if a certain sport makes the symptoms worse, trying other activities may be helpful, and;
- Using pads or supportive strapping to protect the knee during activities that may irritate the knee.
Potential complications of Osgood-Schlatter disease include:
- A permanent, painless bump on the knee. It may still be tender when kneeling;
- Bone fragments (called ossicles) developing in the patellar tendon leading to persistent pain, and;
- Genu recurvatum, a condition in which the knee overextends. This occurs when the growth of the shinbone (tibia) is affected and the front part of the bone stops growing prematurely, changing the position of the knee.
Rarely, symptoms may continue to be troublesome after the bone stops growing. Surgery is not commonly recommended, but may be performed to:
- Remove bone fragments from the patellar tendon, or;
- Remove some of the tissue of the enlarged tibial tuberosity.
For most children with Osgood-Schlatter, symptoms will settle as their bones stop growing. For a few children, some pain may continue, but the condition rarely requires surgery.
Because the initial injuries are small, Osgood-Schlatter disease is difficult to prevent. However, following medical advice may help to reduce the risk of the condition becoming worse and doing more damage to the bone.