The cause of knee pain is not always clear, because an injury or degeneration does not always have to be accompanied by pain. Magnetic resonance or any other examination method is therefore not sufficient to make a correct diagnosis and determine the appropriate form of treatment.
Depending on the cause, the knee pain can be accompanied by the following complaints:
- swelling and stiffness,
- reddening of the skin and overheating,
- weakness or instability,
- Cracking during movement,
- Joint blockages, extensor or flexion inhibition of the knee joint.
Pain around the kneecap
Pain that is noticeable around the kneecap (patella) occurs in the anterior knee region.
If the symptoms are behind the kneecap, a patellofemoral pain syndrome could be present; in this case, the pain becomes noticeable after prolonged sitting (from 10 minutes) with the knee joint bent, for example in the cinema, after exercise and when cycling.
The real cause of this disorder seems to be neuromuscular, i.e. incorrect coordination between hip and thigh muscles.
When the patient walks or climbs stairs, the contraction of the outer muscles of the gluteal and thigh is not sufficient.
The result is an internal rotation and adduction of the hip.
Young female athletes may suffer from chondromalazia, a common cause of discomfort at the back of the kneecap.
Pain below the kneecap is usually caused by tendinitis of the kneecap ligament (patellar tendon).
This can occur on both sides, but usually either the right or left knee is affected.
Tendinitis of the patellar tendon causes pain when running (especially downhill) and during certain exercises, such as squats and lunges.
Most other causes of anterior knee pain are damage caused by overloading and starting insidiously, such as:
- tendinitis of the quadriceps tendon, which causes pain above the kneecap,
- Inflammation of the kneecap ligament.
Pain on the outside
The most common causes of pain on the outside of the knee:
- Iliobial ligament syndrome, also known as runner’s knee or tractus syndrome; it is an inflammation caused by overload that begins when running.
- External knee pain can also be caused by damage to the outer meniscus or the outer ligament (lateral collateral ligament); in this case, swelling is also visible and the flexion and stretching movement are limited.
- The lesion of the knee cartilage can provoke pain in the outer part of the knee joint, which occurs gradually.
Pain on the inside
The most common causes of pain on the inside of the knee:
- Injury to the inner ligament (medial collateral ligament), which also leads to inflammation and restriction of movement.
- An inward-facing knee distortion can also cause damage to the articular cartilage, the inner meniscus or the anterior cruciate ligament.
- The lesion of the cartilage can begin gradually and be the reason for pain in the inner knee region.
- Internal meniscus damage is a common cause of knee pain, causing swelling and joint blockages.
- Thickening of the plica fold can cause great pain in the knee joint.
- Bone edema is the inflammation of a bone forming the knee joint (usually the femur), usually as a result of trauma. The magnetic resonance indicates the edema as a bright spot. The inflammatory fluid accumulates in the bone and causes severe pain and restriction of movement, those affected can usually not bend the knee further than 90 °.
Anterior internal pain
If the knee hurts on the front inside, the possible causes are:
- damage to the inner meniscus,
- Inflammation of the Hoffa fat body.
A few centimeters deeper, tendonitis of the pes anserinus can occur.
The discomfort can also be felt when walking.
In girls and women, anterior knee pain can also be caused by excessive elasticity.
Flexibility is often seen as an advantage, but in reality it can promote disorders of the musculoskeletal system by affecting control over the joints.
Anterior external pain
Pain on the side of the kneecap may be caused by injury to the anterior outer meniscus or patellofemoral pain syndrome, in which the kneecap moves outside its normal sliding surface.
Posterior knee pain
At the back of the knee, in the hollow of the knee, there is a fluid-filled sac called Baker’s cyst; if this cyst swells as a result of a knee injury, it can cause pain.
Tendonitis of the hamstring muscles (thigh biceps, semitendinosus and semimembranosus) can cause pain in the posterior knee region, where the tendons attach, but this rarely happens.
Normally, tendonitis is an injury caused by overloading, the symptoms develop gradually.
Sports that do not excessively load the joint can continue to be practiced; however, breaststroke is to be avoided because the symptoms could worsen.
Nervous or muscular disorders can cause progressive pain in the posterior knee area:
- A herniated disc in the lumbar spine can irritate the sciatic nerve and provoke sciatica; in this case, the pain is very intense.
The symptoms are also felt in the calf and foot.
- Piriformis syndrome causes discomfort that can be felt from the vessel to the knee; the symptoms worsen with rotation of the hip and sitting.
Diffuse knee pain
Arthritis for knee pain
This is the most debilitating form of arthritis and an autoimmune disease that can affect virtually any joint of the human body, including the knee joint.
Even though rheumatoid arthritis is a chronic disease, severity and symptoms can occur intermittently.
This form of arthritis occurs when uric acid crystals are deposited in the joints.
Gout usually hits the big toe, but can also appear in the knee joint.
Pseudogout is often confused with gout; it is caused by calcium crystals that accumulate in the synovial fluid.
The knee joints are most often affected by pseudogout.
Infections (or infectious arthritis) Gonorrhea (gonorrhea)
is a sexually transmitted disease that can infect the knee joint.
Signs and symptoms
A knee infection causes pain and swelling.
An infected knee can cause fever and chills.
With mild infection, fever does not necessarily occur.
swelling and pain in the knee must be carefully examined.
The therapy provides for antibiotic treatment and possibly the suction of synovial fluid or surgical drainage.
Knee inflammation can occur as a result of force on the knee joint or as a result of a sprain in which ligaments or other internal structures are injured, for example when skiing.
Swelling (edema or joint effusion) is not always a sign of damage to bones, cartilage, ligaments or menisci, it can also result from excessive stress, trauma and sprain that do not cause damage.
Also, arthritis can provoke edema in the anterior or posterior knee region, at the level of Baker’s cyst.
After surgery (e.g. reconstruction of the anterior cruciate ligament), the swelling persists for a few months.
Synovitis is the inflammation of the inner synovial capsule skin (synovial membrane); it can occur as a result of knee surgery, the effusion concentrated around the kneecap or in the Baker’s cyst.
Pain in children
Children may feel pain during the growth phase.
Osgood-Schlatter disease causes pain in the anterior knee region, where the patellar ligament (patellar tendon) attaches to the top of the shin. Athletes are affected, rest relieves the pain.
Pain while walking
Those who regularly walk on the street are likely to suffer from knee pain over time.
Knee problems of the runner are caused by excessive strain and are the result:
- an incorrect foot position (overpronation of the foot),
- bad running shoes.
The term runner’s knee refers to iliotibial ligament syndrome, in which the tendon runs over the underlying bone and creates pain on the outside of the knee joint.
Pain during knee flexion
With limited movement and swelling, there is almost certainly a lesion, but a bruise can also reduce the flexion and extensor movement.
If the knee cannot be fully extended, it will probably be meniscus damage.
Pain at rest
If the pain occurs at rest and also at night while sleeping, it could be caused by:
- advanced osteoarthritis,
- bone tumor, such as osteosarcoma,
Morning knee pain, which subsides about half an hour after getting up, is typical of osteoarthritis; On the other hand, if the pain persists for at least an hour, it is more likely to be psoriatic or rheumatoid arthritis.
Pain after knee surgery
After surgery, it is quite normal to feel pain in the first few weeks afterwards.
How long the postoperative pain lasts depends on the type of operation: when a meniscus (meniscectomy) is removed, the pain persists for about 10 – 15 days, if it is the reconstruction of the anterior cruciate ligament or a knee prosthesis, the pain can also last for 3-4 months.
The stiffness is felt especially “in the cold state” and when waking up; it is quite normal if, at the first stage of rehabilitation, there is pain when stretching the leg.
Knee pain from the point of view of naturopathy
Naturopathy believes that poor diet and lack of exercise are the causes of knee pain.
Many patients were able to improve their condition or be completely cured with the help of the blood group diet.
According to this diet, the reason for the knee pain is a defensive reaction of the body to some foods.
In addition, according to this theory, arthrosis or other diseases do not cause symptoms if the patient eats correctly.
Foods to avoid for painful and inflamed knee joints:
- milk and dairy products,
- excessive amounts of fruit, especially in blood group 0; you can eat fruit in the morning without exaggerating.
These are the main culprits, but some individuals may develop immune reactions even after eating other foods, such as after eating nightshade plants:
- Goji berries
A visit to the doctor is necessary in the following cases:
- The knee can not be fully loaded.
- The knee joint is swollen.
- The knee joint cannot be fully bent or stretched.
- The leg has a visible deformation.
- In case of fever along with redness, pain and swelling of the joint.
- Feeling of instability in the knee joint.
During the physical examination, the doctor must examine the knee for swelling, pain, stiffness, overheating and bruising.
After that, the range of motion must be evaluated, can the knee be fully bent and stretched?
It is important to examine the integrity of the ligaments and menisci by means of special knee tests.
- X-ray. The doctor may order an X-ray examination to visualize:
- tumor mass,
- condition of an earlier inserted knee prosthesis,
- Varus or valgus position of the knee joint, i.e. X- or O-legs.
- Computed tomography (CT). A CT scan helps diagnose bone problems and indicates the presence of foreign bodies.
- Ultrasound (sonography). This method uses sound waves to create real-time images of the soft tissue structures in the knee.
With this examination method, however, the inner area of the joint cannot be seen and thus it is unsuitable for assessing menisci, bones, ligaments and synovial fluid.
- Magnetic resonance imaging (MRI) uses radio waves and a strong magnet to provide detailed insights into the inside of the knee. This procedure provides important information about injuries to soft tissues such as ligaments, tendons, cartilage and muscles.
- Laboratory tests. If an infection, gout or pseudogout is suspected, the doctor will probably prescribe a blood test and arthrocentesis (this is a joint puncture in which some fluid is taken from the joint with the help of a needle and examined in the laboratory).