Running is a popular sport that is easy to incorporate into your daily life. However, if you don't run in the right way, it can put stress on your knees, so many people suffer from a condition called ``runner's knee.''
Even though it's called ``runner's knee'', multiple conditions are associated with knee pain caused by running. Of particular note is ``patellar chondromalacia.''
This time, we will explain in detail the various symptoms of runner's knee, focusing on patellar chondromalacia. We will provide useful information for everyone who enjoys running, including causes, treatments, and preventive measures, so please check it out.
table of contents
What is patellar chondromalacia?
Patellar chondromalacia is a condition in which the patellar cartilage behind the patella (kneecap) becomes soft or degenerates.
Although it is on the back side, it is sandwiched between the femur and patella, so it is located at the front of the knee.
symptoms
The main symptoms are pain, swelling, and discomfort in the knee.
pain
Pain is especially likely to occur around or just below the kneecap. At first, the pain is felt only during or after exercise, but as the condition progresses, the pain can be felt even during daily activities.
Also, when you bend and straighten your knee, you may feel a rough or slightly stuck sensation inside your knee. This is due to the unevenness of the softened cartilage surface.
In everyday life, I feel pain in the front of my knees when I squat deeply. Also, standing up from a squatting position puts the most pressure on the cartilage, so there are many cases where you will feel pain.
Also, when you go down the stairs, you may feel a sharp pain in the front of your knee due to strain on the cartilage. Furthermore, knee pain is also likely to occur when trying to stand up after sitting for a while. It is good to understand that when you sit for a long time, the cartilage temporarily becomes insufficiently lubricated, meaning that synovial fluid, which plays a protective role, does not reach the cartilage sufficiently.
Swelling (hydroarthritis)
There may be slight swelling around the patella. This swelling is caused by an increase in the amount of synovial fluid (joint fluid) produced as a result of cartilage damage, rather than red swelling due to inflammation, and is more accurately described as ``water accumulation.''
In addition, as joint edema progresses, the discomfort may increase further, and the pressure within the joint may increase, causing pain throughout the knee.
Causes of patellar chondromalacia
It is said that when running, a force approximately 2 to 3 times your body weight is applied to your knees. This stress is repeated every time you land, which causes damage to the cartilage behind the patella.
However, it cannot be said that just running normally will increase the chance of developing patellar chondromalacia. Please be aware that the following factors may increase your risk of developing the disease.
Rapid increase in training volume
A sudden increase in the amount of training can also increase the risk of developing patellar chondromalacia. For example, someone who was only running 5km once a week might suddenly increase that to 10km three times a week. Excessive stress is placed on the cartilage behind the patella, causing softening and degeneration.
Cartilage has the ability to adapt to moderate loads. It is okay to gradually increase the load. If the load is increased over time, the cartilage will gradually become stronger and able to withstand the greater load.
structural problems
People with a large Q-angle (the angle formed by the quadriceps and patellar tendon) tend to have their patella pulled outwards, which puts more stress on the cartilage.
The type of arch of the foot also affects the risk of developing the disease. This is because, in cases such as those with pes planus (flat feet), excessive stress is placed on the inside of the foot during running, which adversely affects the position of the knee, resulting in uneven pressure being applied to the patellar cartilage.
Many of these anatomical factors are inborn, but they can be improved by choosing the right shoes and, in some cases, using insoles.
Muscle balance problems
In order to keep your knees healthy, it is better to think about the overall balance and create a plan that strengthens weak muscles rather than further strengthening already strong muscles.
Especially in the case of patellar chondromalacia, the balance between the quadriceps (front thigh muscles) and gluteal muscles (buttocks muscles) is important.
For example, if your quadriceps are too strong and your glutes are weak, your knees will move too far forward when you run, putting too much pressure on your patella (kneecap). This is one of the causes of cartilage softening and degeneration.
Weakness of the vastus medialis muscle, which is part of the quadriceps muscle, can also cause patellar chondromalacia. If the vastus medialis muscle is weak, the patella will not move flexibly and the pressure on the cartilage will tend to be uneven.
Core strength is also important. If your core is weak, your body will be more likely to lose its balance while running, which will put extra strain on your knees and increase stress on your patellar cartilage.
runner's knee in a broad sense
As mentioned above, "runner's knee" itself does not refer to a specific disease. The collective term ``runner's knee'' refers to several knee conditions caused or exacerbated by running. In addition to patellar chondromalacia, other symptoms of runner's knee include:
Iliotibial banditis
This condition is most commonly referred to as ``runner's knee.'' Pain often occurs on the outside of the knee.
Patellofemoral pain syndrome
It is characterized by pain around the patella and is sometimes treated as a type of runner's knee.
Patellar tendonitis
Also known as jumper's knee, it is also commonly seen in runners. Because the patellar tendon is attached to the underside of the kneecap, pain often occurs on the lower side of the knee.
Thrush foot inflammation
It is a condition in which pain is felt on the inside of the knee and is sometimes considered a type of runner's knee.
Meniscal injury
It can be aggravated by running and is sometimes treated as a type of runner's knee.
Each has different characteristics, but all can be caused or worsened by running.
Diagnosis of patellar chondromalacia
Evaluate using various image diagnoses. MRI tests can non-invasively evaluate the condition of cartilage. Softening is determined by changes in cartilage thickness and signal intensity. Ultrasound tests can evaluate cartilage thickness and surface irregularities.
In addition, the cartilage may be directly observed using arthroscopy and the state of damage may be evaluated using a grade of 0 to 4 called the Outerbridge classification.
Treatment of patellar chondromalacia
In the early to middle stages of patellar chondromalacia, this conservative treatment may be the first choice.
rest your knees
During the acute phase, rest your knee for 2 to 3 days and avoid painful movements. It is not necessary to take complete rest, and in many cases there is no problem as long as you are able to move about in your daily life.
If the pain subsides, gradually increase your activity level, but refrain from strenuous exercise that causes pain. It usually takes about 2 to 4 weeks, but it depends on the severity of the symptoms.
rehabilitation
Rehabilitation is performed with the aim of reducing the burden on the cartilage. If you have patellar chondromalacia, try a combination of stretching and muscle training to effectively strengthen your muscles.
Stretching the quadriceps muscles increases flexibility around the patella.
Strengthen the vastus medialis to support proper movement of the patella, while training the gluteal muscles to reduce the burden on the knees and improve overall lower limb balance. Strengthening your core muscles is also important.
In most cases, the stage of undergoing rehabilitation is when the symptoms have already appeared, so be sure to carry out training under the supervision of a specialist to avoid worsening the pain.
drug therapy
Analgesics and hyaluronic acid injections may be given to reduce inflammation and pain.
surgery
Most cases of patellar chondromalacia improve with conservative treatment, but if the symptoms are severe or if conservative treatment is not sufficiently effective, surgical treatment may be considered.
arthroscopic surgery
This is the most common surgical method. An endoscope is inserted through a small incision and the damaged cartilage is treated. Specifically, damaged cartilage is removed, the cartilage surface is smoothed, and small holes are made in the subchondral bone to encourage the formation of new cartilage-like tissue.
regenerative medicine
This is the latest medical treatment that is attracting attention as a treatment that can regenerate cartilage even when surgery is not an option.
Autologous chondrocyte transplantation
This is a method of collecting cells from the patient's own healthy cartilage and culturing and multiplying the collected cells. The increased cells are then transplanted to the injured area.
stem cell therapy
A treatment method that uses stem cells collected from bone marrow or adipose tissue to promote differentiation into cartilage cells. It has attracted attention because it can form new cartilage tissue when injected or transplanted into damaged areas.
Platelet-rich plasma (PRP) therapy
This is a method of extracting concentrated platelets from the patient's own blood. PRP, which is rich in growth factors, is injected into the injured area to slow the rate of cartilage deterioration and promote repair.
Other measures
You also need to pay attention to your lifestyle and running, which can put stress on your knees.
weight control
Excess weight increases stress on the knees. Maintain a healthy weight with a healthy diet and moderate exercise.
hydration
Proper hydration is also important for joint lubrication, so make sure to hydrate frequently.
Choosing the right shoes
Running shoes play an important role in absorbing shock to the knees. Choose shoes that match your foot width and arch height. Adequate cushioning is also necessary to absorb shock. Also, it is not a good idea to keep wearing the same shoes forever just because they fit well. This will reduce the cushioning properties and the support function. If the grooves on the soles of your shoes become shallow, this is also a sign that they need to be replaced, so be sure to change them regularly.
summary
By practicing preventive measures on a daily basis, you can significantly reduce the risk of patellar chondromalacia. However, the optimal method varies depending on the individual's constitution and situation. If the pain persists or you have any concerns, be sure to consult a specialist.