Sinding-Larsen-Johansson Syndrome

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Sinding-Larsen-Johansson syndrome (SLJ) is an injury directly to the growth plate where your patella (kneecap) attaches to your patellar tendon, the tendon that connects your kneecap to your shin bone (tibia). SLJ is also an injury to the tendon at the spot where the tendon leaves the patella, which is the inferior pole of your kneecap. It almost always affects children ages 10-15 who participate in sports activities or are excessively active.

There is another condition called Osgood-Schlatter disease that results in a similar effect as for Sinding-Larsen-Johansson syndrome. They both are very similar and share several causes, symptoms, and treatments. In fact, both conditions refer to injured kneecap tendon in younger adults and children. The only main difference is which location of the patellar tendon is injured. Sinding-Larsen-Johansson syndrome is an injury to the top of the tendon while Osgood-Schlatter disease affects the bottom of the tendon.

Causes & Symptoms of Sinding-Larsen-Johansson Syndrome

Overuse of the patella is usually the result of SLJ in growing adolescents. When the quadriceps muscles repeatedly contract, this creates a pulling force on the bottom of the kneecap. This occurs most commonly in children who are active during their growth spurts.

Furthermore, overuse injuries can also lead to stress fractures. Stress fractures are weak spots or tiny cracks in the bone caused by continuous overuse. Stress fractures often occur in the foot after training for basketball, running, and other sports. Generally, the quadriceps are known as the large muscle group on the front of the thigh. This muscle then attaches to the kneecap.

When you straighten your legs to either walk or run, the quadriceps pull at the patellar tendon, so the lower leg moves forward. This force puts stress on the bottom of the kneecap at the growth plate. While children are going through growth spurts, the bones and muscles do not always grow at the same velocity.

This imbalance means that as the bones grow longer, the muscle becomes tight, putting painful stress on the growth plate where the tendon meets the bone. Poor biomechanics and tightness in the muscles of the lower extremities also contribute to Sinding-Larsen-Johansson syndrome.

Symptoms of Sinding-Larsen-Johansson syndrome begin with a painful sensation located in the front of the knee and near the bottom of the kneecap that worsens with knee motions (running, climbing stairs, or jumping) and becomes more severe when attempting to knee or squat. Other symptoms associated with Sinding-Larsen-Johansson syndrome include:


Pain during athletic motion

A young athlete with patellar overuse may feel a sharp, throbbing pain beneath their kneecap during intense competition. At the start, the pain may become worse with athletic activity and recede with rest. If the pain is left untreated, the pain may become much more constant even during times of rest. The kneecap pain will be worst when kicking or bending the knee, as these actions activate the patellar tendon.


Like any other kneecap injury, Sinding-Larsen-Johansson syndrome may cause swelling of the knee joint. Most adolescents may notice that their knee looks swollen and has a reduced range of motion.

Bruising / redness

In severe cases, discoloration of the knee joint can become noticeable upon the injury.


Many athletes with extreme cases of overuse of the patella may notice increased pain in their knees due to performing regular daily activities.

Who gets Sinding-Larsen-Johansson Syndrome?

Sinding-Larsen-Johansson syndrome comes with risk factors that are present in children who are currently experiencing growth spurts. Below is a detailed description of some of the most common risk factors linked to SLJ:



Sinding-Larsen-Johansson syndrome occurs during puberty’s growth spurts. The age ranges differ by gender because girls enter puberty much earlier than boys. Therefore, SLJ syndrome usually occurs in girls ages 8 to 10 years old, while this condition occurs in boys ages 9 to 11 years.


SLJ syndrome is more common in boys, but the gender gap is narrowing as more girls become involved with sports.


Children and younger athletes who are involved in a lot of running and jumping activities (such as basketball, soccer, skiing, and football) are at a greater risk for developing Sinding-Larsen-Johansson syndrome due to increased pulling of the kneecap tendon on this growing area.


Tightness in the quadriceps muscles can increase the pull of the kneecap’s tendon on the growth plate at the top of the shin bone.

How Does Sinding-Larsen-Johansson Syndrome Affect You? How Serious is it?

It is impossible for SLJ syndrome to affect adults, although it is rare. In fact, if you have similar symptoms to Sinding-Larsen-Johansson syndrome and are over 15 years old, you are likely to have another condition such as jumper’s knee.

There are many causes of adult knee pain in general. In severe cases, there can even be serious complications linked to this condition.

If you try to work through your pain, ignoring your body’s warning signs, you could cause increasingly larger tears in the patellar tendon. Knee pain and reduced function can persist if you don’t tend to treat the issue, and you may progress to the more serious patellar tendinopathy.

Recommended Treatment & Rehabilitation for Sinding-Larsen-Johansson Syndrome

During a diagnosis for Sinding-Larsen-Johansson syndrome, a regular three-step diagnostic process is made by a physician.

He or she may begin by asking for a detailed medical history, leading to a physical examination to identify the cause. If a physical exam has failed to identify the injury, your doctor may order additional imaging tests to rule out the condition, such as:

  • Bone scan – A nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation.
  • Magnetic Resonance Imaging (MRI) – This is a test that uses a combination of large magnets, radio waves, and a computer to produce detailed images of structures within the body.
  • X-ray – This uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs for clear results of the disease.

If there are symptoms related to swelling due to Sinding-Larsen-Johansson syndrome, treatment may be pursued to try to calm the inflammation of the knee. Some of these treatments include:



Allowing the knee to rest is the first step in treatment, and often the only step necessary to resolve the symptoms of this condition. Rest may also include immobilization of the knee in a slightly bent position to take the pressure off the condition.


Anti-inflammatory medications

Oral medications can be used to help relieve pain and reduce inflammations. Typically, non-steroidal anti-inflammatory drugs (NSAIDs) are used to help calm the irritated kneecap. In more severe cases, a cortisone injection, also a powerful anti-inflammatory medication, can both be administered to help address the problem.


Compression knee braces

Knee braces can help limit mobility and support the kneecap. A simple patellar compression knee brace is often the most helpful type of brace for this condition.


Ice and heat therapy

Decreasing inflammation and relieving pain is often accomplished with the application of ice packs directly to the front of the kneecap. keep the ice pack applied for 20-30 minutes every 3-4 hours for rapid short-term relief. You can also add a heat pack to increase blood circulation in the affected area.

If you have been immobilized, then you can begin a physiotherapy session. During physiotherapy for Sinding-Larsen-Johansson syndrome, your therapist will begin by educating you on activity modification and implementing a period of active rest so that your symptoms can improve.

Taking an active rest means decreasing your activity intensity or duration such that you are not aggravating your knee. Some activities, however, may need to be completely avoided or replaced by less stressful ones. Avoiding excessive use of the stairs, as well as resisted weight training can help reduce further kneecap pain.

Your physiotherapist may also use electrical modalities such as ultrasound or interferential current to help ease your pain or decrease any swelling that may exist. He or she will use an additional tape or flexible brace to assist with your symptoms. The aim of this type of treatment is to help guide the kneecap through its proper range of motion while you move the knee during your rehabilitation exercises and during everyday activity.

Once your symptoms begin to subside, your physiotherapist will design a specific exercise plan in order to ensure you maintain your full knee range of motion. The following exercise examples include:



Stand straight with your feet hip-width apart. Next, lower your bottom down and backward, as if you were going to sit in a chair. Stop when your knees reach about a 90-degree angle. Try not to lean your upper body forward more than a few inches. You may want to move your arms forward for balance or stand next to a wall, counter, or other support. Straighten your legs to return to standing straight, then repeat 2-3 times a day.


Side leg raises

Lie on your side with your injured leg on top. Slowly raise your injured leg toward the ceiling. Hold this position for 10 seconds, then repeat this method 3-4 times a day.


Leg presses

Laying on the floor with the ends of a resistance band or tubing in each hand, bring your knees to your chest. Put the tubing across the bottoms of your feet and take up any slack in the resistance band. Afterward, while keeping your elbows on the floor and your hands by your chest, slowly press on both legs outward, leading with your heels until your legs are straight. Gently return to a bent-knee position before repeating this exercise 3-4 times a day.


Knee extensions

While sitting on a chair with both feet on the floor hip-width apart, slowly raise one leg out in front of you until it’s level with the floor. Then, slowly lower the same leg back to the floor and repeat 2-3 times a day.



Stand tall with feet shoulder-distance apart at the base of a set of stairs. Next, shift your weight onto one foot. Place your right foot entirely on the stop and press yourself up so that your body is up onto the step, placing the left foot next to the right foot on the stair. Slowly lower your left foot back to the floor and steady yourself. Continue this process with your right foot on the step as you repeat this method 2-3 times a day.

Alternative & Homeopathic Treatment for Sinding-Larsen-Johansson Syndrome

If you have mild to moderate symptoms of Sinding-Larsen-Johansson syndrome, you can often treat it at home. Here are some homeopathic treatments that can help you reduce and improve symptoms linked to this condition:


Herbal ointment

Some studies have shown that there are pain-relieving effects of a salve made of cinnamon, mastic, sesame oil, and ginger. They found the salve was just as effective as over-the-counter arthritis creams containing salicylate, a topical pain-relieving treatment.


Tai chi

This is an ancient Chinese form of mind-body exercise that improves balance and flexibility. Tai chi can help reduce pain and increase the range of motion. It also involves deep breathing and relaxation. These aspects may also help reduce stress and help you manage chronic patellar pain.


Willow bark extract

Some patients sometimes use willow bark extract for joint pain, as it may help relieve pain and inflammation. However, it is recommended to check in with your doctor before the usage of this extract.

Ginger extract

Ginger extract are available as supplements and ginger tea. These are used to help reduce arthritic pain.

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