Pediatrics

Growing pains in the knee

Definition - What is knee growing pains?

Growing pains in the knee are pain that occurs primarily at night. Often those affected are awakened by the pain.
The growing pains are usually bilateral and often radiate into the thighs. Since there is no test that can be used to diagnose growing pains in the knee, it is a diagnosis of exclusion. If there is pain in the knee, other possible diseases are ruled out first. If nothing is found, it is usually growing pains.

Causes of the growing pains

The exact causes of the growing pains in the knee have not yet been clarified.

However, there are many assumptions that are mainly based on the fact that the various tissues in the leg do not all grow evenly. Instead, sometimes the bones grew faster, sometimes the muscles and sometimes the ligaments. As a result, the power transmission in the knee changes again and again and different structures are more heavily stressed. After a growth spurt, these structures first have to get used to their unfamiliar new stress. This is the time when the most common growing pains occur.

In addition, the uneven growth can temporarily lead to malpositions in the knee. Overmobility can also arise when ligaments and tendons grow faster than the bones.

You can find additional information at: Acute knee pain - what's behind it?

Concomitant symptoms

Growing pains on the knee are characterized by pain that occurs without an inflammatory component and therefore without swelling, reddening and overheating of the affected knee joint. Usually both knees are affected by the pain. These most often radiate into the thigh muscles. Growing pains in other joints can occur at the same time. This usually affects the legs, i.e. the foot and hip joints. But growing pains in the arms can also occur. In addition to pain in the extremities, many children also experience abdominal pain and headaches. How exactly the pain is related is not clear, but one suspects a psychological component of the disease.

Sleep deprivation may result from waking up at night from pain. This manifests itself in increased daytime sleepiness, headaches, reduced ability to concentrate at school and reduced performance. Sleep disorders can also occur if the affected child learns that they often wake up with pain.

Since the pain is not associated with stress and movement, but rather occurs at rest, the child's sporting activities are usually not affected. School sports or sports in a club and daily physical activities can usually be continued without any problems.

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Duration of the growing pains in the knee

Growing pains in the knee usually occur at night and last for a few minutes to hours. After pain medication, they can usually improve within 30 minutes so that the affected child can sleep again. In the morning, the pain will usually go away.

During individual growth spurts, these pains can appear more frequently. These phases usually last a few weeks. Overall, the growing pains in the knee can occur throughout the growth of the affected child. They usually go away once the child is fully grown. For girls this is usually the case at around 16 years of age, for boys it can continue until they are 18 or 20.

Diseases to be excluded

Schlatter disease

Schlatter's disease or Osgood Schlatter's disease is a disease that causes irritation to the knee. This irritation arises exactly where the patellar tendon (tendon of the kneecap) is attached to the shin bone. The disease occurs particularly in active adolescents, which is why it is very likely that the symptoms are caused by an overload of the kneecap tendon.

The increased occurrence of Schlatter's disease can also be observed during strong growth spurts during puberty. While the pain usually begins in one knee, the other knee is usually affected over time.

The irritation of the tendon can also cause small bits of bone to loosen from the head of the tibia. These are then no longer supplied with nutrients and die after a while. If the disease is discovered before major bone defects develop, the prognosis is good. As a rule, a break in sport is sufficient as therapy. The small pieces of bone that detach from the shinbone can also be deposited in the patellar tendon and cause problems there again and again. In this case, these small bony areas should be surgically removed.

The diagnosis of Schlatter's disease can usually be made based on the typical symptoms. In order to be able to assess the bony situation, however, an X-ray or an MRI is often useful.

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Knee joint disease
Osgood-Schlatter disease

Sinding-Larsen's disease

Sinding-Larsen's disease, or more precisely Sinding-Larsen-Johansson's disease, is similar to Schlatter's disease, due to overstressing of the knee. This leads to irritation where the patellar tendon attaches to the kneecap.As in Schlatter's disease, the irritation and inflammatory reaction can detach small pieces of bone from the kneecap, which then die off. This process is called Ostenekroses (osteo = bone, necrosis = death of tissue).

Sinding-Larsen's disease is usually diagnosed solely on the basis of its clinical symptoms. An ultrasound of the knee can also be performed. The tendon structure of the patellar tendon can be assessed particularly well there. X-rays and MRIs are also used to assess the bones and the surrounding tissue.

As with Schlatter's disease, small pieces of bone can become lodged in the patellar tendon, which cause permanent discomfort and should therefore be surgically removed. Otherwise, adequate therapy with painkillers and cooling of the knee are the measures of choice. In order to get rid of the symptoms permanently and to avoid a relapse, a sport break may be necessary, which lasts a quarter to a full year.

More information can be found here: Sinding-Larsen's disease

Osteochondrosis dissecans

In osteochondrosis dissecans, a small portion of the cartilage plus / minus the bone in the joint loosens. This piece of cartilage can then be found in the joint as a free joint mouse.

The cause of this disease is probably small so-called microtraumas that occur, for example, in sports with high stress on the knee. Due to the minor trauma, the cartilage is not adequately supplied with nutrients and dies. This process runs in three phases: First, it begins with the so-called Slumber stage, in which the cartilage and possibly the underlying bone are insufficiently supplied. In the second phase, a slightly damaged cartilage layer is created, which begins with the first detachment processes from the rest of the bone. In the third stage, the fragment has loosened and forms a free joint body.

The therapy of osteochondrosis dissecans is hotly debated and depends on the age and the severity of the disease. The methods range from conservative treatment without high-impact sports (sports with high stress on the joints) as well as painkillers and physiotherapy, to fixing the bone area that has not yet been completely loosened, to removing the free joint mouse. In adults, it is also possible to consider implanting a well-perfused bone from the iliac crest in the place of the detached piece of bone, since the heavily stressed joint surface is more even again and there is less consequential damage such as osteoarthritis.

For more information, see: Osteochondrosis dissecans

König's disease is a special form of osteochondrosis dissecans that occurs in children. Before the growth is over, the bones are not yet completely closed, instead they have a lot of cartilaginous parts that bring great growth potential with them. At the same time, this leads to a reduced strength of the bones before the growth is complete. Osteochondrosis dissecans, in which small pieces of cartilage and bone become detached from the joint surface, can therefore easily develop. In König's disease, the articular surface of the thigh bone in the knee is affected.

Juvenile arthritis

Juvenile arthritis is a rheumatological disease that occurs in children and adolescents. In doing so, the body attacks its own joints for reasons unknown so far, which is why chronic inflammation occurs in the affected joints.
The typical symptoms are pain, as well as overheating and swelling of the affected joint. There may also be an effusion in the joint. In order to be able to make a diagnosis of juvenile arthritis, the disease must have lasted for more than 6 weeks and occur in those under the age of 16. The therapy consists of dosed exercise and physiotherapy as well as the administration of painkillers and anti-inflammatory drugs.

Read more at: Juvenile arthritis

Reactive arthritis

Reactive arthritis is inflammation of the joints that occurs after a bacterial infection. Typically, the bacterial infection is located in the gastrointestinal tract, the respiratory tract, the lungs and the urinary tract.
Reactive arthritis usually affects a single joint on the legs, often it is the knee joint. Characteristic is the expression on only one side. Treatment for reactive arthritis consists of physical therapy, pain medication, and anti-inflammatory agents.

More on this: Reactive arthritis

Purulent arthritis

Purulent arthritis occurs when a bacterial infection occurs in the joint itself.
The pathogens can get into the joint via the bloodstream or migrate into the joint from neighboring structures such as muscles. Purulent arthritis is also possible after an operation on joints, as this allows bacteria to enter the joint from outside. Typically, there is pain, swelling, reddening and functional impairment in the joint. Fever is also a possible symptom. Treatment consists of giving antibiotics.

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Radiating hip diseases such as M. Perthes

Perthes' disease is a disease of the hip joint in which, for reasons that are not yet known, bone tissue dies on the femoral head. Presumably, a reduced blood flow to the femoral head or a hormonal imbalance is to blame for the bone necrosis. As a rule, one-sided hip pain occurs with the disease.

Perthes' disease is diagnosed with an X-ray. Ultrasound of the hip already shows an effusion in the hip joint, which confirms the suspicion of M. Perthes. Depending on the progression of the disease, physiotherapy and orthotics may be sufficient treatment; in advanced stages, surgery is usually necessary. Since the hips and knees form a functional unit when walking, many hip diseases such as M. Perthes in children are initially noticeable due to knee pain.

Additional information here: Perthes disease

diagnosis

The diagnosis of growing pains consists primarily in ruling out other diseases. A clear diagnosis of growing pains in the knee cannot be achieved through tests.

Instead, diseases such as injuries and infections in the knee must be ruled out. Joint inflammation and arthritis can usually be ruled out with blood tests. Bone lesions or tumors become visible in the X-ray image. Injuries to menisci, ligaments or muscles can often be ruled out with a good medical history (questioning the person concerned by the doctor). If there is still a suspicion, MRI imaging can provide clarity.

treatment

The treatment of growing pains is only symptomatic. Since an exact cause of the disease has not yet been discovered, no causal therapy can be carried out. In addition, the growing pains are harmless and have a good prognosis, which is why symptomatic therapy is much more sensible.

Therapy for growing pains in the knee therefore primarily consists of adequate administration of painkillers such as ibuprofen or paracetamol. Care should be taken to adjust the dose to the child's body weight. Excessive doses can damage the kidneys and / or liver. In addition, the pain relievers should be taken a maximum of ten days a month. Otherwise, drug-associated headaches, for example, can occur.

Since the growing pains in the knee are often accompanied by tense muscles, applying heat to the knee often helps. However, some children also benefit from cooling their knees. In this case, a cooling and pain relieving ointment such as Voltaren or Docsalbe can also be applied to the knee.

However, the most important part of treating the growing pains of the knee is properly managing the condition. It is therefore essential that parents and children are informed about the harmlessness of growing pains. Although the pain does not indicate a serious medical condition, it should be taken seriously by parents and doctors. In this way, the child can usually better deal with the symptoms.

Prognosis of the growing pains in the knee

The prognosis for growing pains is extremely good. With this type of pain, there is no physical damage, so the disease does not cause any consequential damage.
As a rule, the growing pains end with the end of the growth phase, i.e. the end of puberty.

In order to prevent the pain from becoming chronic, it is important to ensure adequate therapy and that the child's symptoms are taken seriously during the pain phases. In this way you can ensure that the child processes the growing pains mentally well and that no secondary symptoms develop.