Knee pain

The doctor conducts a visual examination and palpation of a patient with knee pain

Knee pain- This is a sign of pathological processes affecting the cartilaginous, bone or soft tissue structures of the femoral-tibial and femoral-patellar joints. Arthralgia can be based on trauma, inflammatory and degenerative diseases of the articular apparatus and periarticular structures. Patients may complain of sharp, aching, burning, throbbing and other types of pain that occur at rest or when moving, supporting, bending and extending the leg at the knee. Diagnostics of causal pathology includes instrumental imaging methods (Rg, ultrasound, CT or MRI, arthroscopy), puncture of the joint capsule, biochemical and immunological analyzes. Until the diagnosis is clarified, rest, joint immobilization, NSAIDs and analgesics are recommended.

Causes of knee pain

Traumatic injury

Usually they are the result of household trauma, often found in athletes: runners, jumpers, participants in playing sports. Developed by a fall, direct impact or twisting of the leg. Manifested by sharp pain at the time of injury. In the future, the pain syndrome becomes less pronounced, accompanied by increasing edema. Abrasions and bruising are possible. As frequency increases, the following injuries are identified:

  • Knee injury. . . Occurs when falling to the knee or hitting it directly. At first, the pain is sharp, hot, sometimes burning, but bearable, later - dull, aching, aggravated by movements. Bruising is possible. The leg support is preserved. Sometimes a knee injury is complicated by hemarthrosis, in such cases the joint gradually increases in volume, becomes spherical, a feeling of pressure or bursting is added to the pain syndrome.
  • Ligament rupture.It is found after twisting the leg, its forcible twisting, bending or overextension in a non-physiological position. The painful sensations are stronger than with a bruise; simultaneously with the onset of pain, a person can feel how something is torn (similar to how ordinary tissue is torn). It is accompanied by a significant limitation of movement, support, twisting of the limb, rapidly increasing hemarthrosis.
  • Intra-articular fractures. . . They are detected by impacts, falling and twisting of the leg. In case of injury, a person feels a very sharp, often unbearable sharp pain, sometimes a crunch is heard. The patients themselves with intra-articular fracture describe their feelings as follows: "the pain is such that it darkens in the eyes, the world ceases to exist, you don't understand anything. "Subsequently, the pains become less severe, but remain high in intensity. Support is usually impossible, movement is almost completely limited. Edema and hemarthrosis progress rapidly.
  • Dislocation.Is the result of a blow or fall to the knee. At the time of dislocation of the patella, a sharp pain occurs, accompanied by a feeling of bowing of the leg and displacement in the knee. No movement possible, the reference function can be saved. On the front surface of the knee, a pronounced deformation is visible, which is subsequently smoothed out due to the increasing edema. Sometimes hemarthrosis joins.
  • Pathological fractures.They develop with minor injuries, are a consequence of a decrease in bone strength in osteoporosis, osteomyelitis, tuberculosis, bone tumors. The pains are aching, dull, reminiscent of the pain syndrome with a bruise. Signs indicating a pathological fracture are limitation or impossibility of support on the leg, a feeling of instability in the knee, sometimes deformity, bone crunch during movement.
  • Damage to the menisci.Meniscus tears are formed during twisting, impact, intense forced bending or extension of the knee, sharp turn with a fixed leg. At first, a person feels a special click and a sharp shooting pain in the depths of the joint. Then the pain decreases somewhat, but becomes diffuse, sometimes - burning, bursting, intensifies when trying to support and move. The volume of the knee increases due to edema and hemarthrosis. Support becomes impossible, movements are sharply limited.
Acute knee pain due to traumatic injury

Inflammatory pathologies

They can be infectious and non-infectious (post-traumatic, toxic-allergic, metabolic, post-vaccination). Abundant blood supply to the synovial membrane and periarticular tissues promotes the rapid development of inflammation in response to direct and indirect effects, and a large number of nerve endings causes a pronounced pain reaction. The inflammatory process is often accompanied by synovitis (accumulation of aseptic fluid in the joint), with infection, accumulation of pus is possible.

  • Arthritis.Gonarthritis occurs after trauma, sometimes complicates infectious diseases, and is detected in rheumatic diseases. May be acute or chronic. Knee pains are usually dull, aching, pressing or pulling. At first, the pain is not intense and intermittent, intensifying in the evening or after exercise. Then the starting pains join, the intensity and duration of the pain syndrome increases. The joint swells, the skin over it turns red, its temperature rises. With synovitis, the contours of the knee are smoothed out, there is a feeling of bursting. With suppuration, the severity of pain increases sharply, they become twitching, deprive you of sleep.
  • Synovitis.It is not an independent disease, complicates many acute and chronic pathologies of the joint. It is formed within a few hours or days. Initially, pain is insignificant or absent, a feeling of fullness prevails. The knee is spherical, with a large amount of fluid, the skin is shiny. Movement is somewhat limited. When infected, the pain becomes pronounced, pulsating, twitching, intensifies with the slightest movement and touch.
  • Bursitis.Inflammation of the joint capsules located in the patella and popliteal fossa usually occurs when the knee is overloaded and its repeated injuries (for example, with constant support on the knees). With bursitis, pains are local, dull, not intense, appear at a certain position of the limb, after a characteristic load, decrease with a change in the position of the leg, massaging the affected area. If the posterior bag is affected, painful sensations are possible during the ascent or descent of the stairs. Minor local edema is sometimes determined. With suppuration of the bursa, the pain becomes sharp, twitching, baking, combined with hyperemia, edema of the affected area, symptoms of general intoxication.
  • Tendinitis.Usually detected in overweight men and athletes, it affects the patella's own ligament. At first, the pain syndrome appears only with very intense exertion, then with standard sports loads, then with daily physical activity or at rest. Pain with tendinitis is localized in front just below the knee, dull, pulling, with the progression of the disease, sometimes paroxysmal, in some cases accompanied by mild redness and swelling, aggravated by pressure. Movement is usually in full, less often slightly limited. A tear or rupture of the ligament is possible due to a decrease in its strength.
  • Lipoarthritis.Hoff's disease affects the layers of adipose tissue located under the patella. It is observed with constant overload of the knee or becomes the result of an old injury. More often it affects athletes, older women. A person complains of dull aching pains in combination, some limitation of extension. With the aggravation of the pathology, the pain begins to bother at night, there is a feeling of instability of the knee, bowing of the leg. When pressing on the side of the patella, a soft crack or creak is heard.

Autoimmune processes

The cause of diseases of this group is the production of antibodies to the body's normal cells with the development of immunocomplex aseptic inflammation of the synovial membrane and cartilage, the phenomena of vasculitis. Pathologies in most cases are chronic, without treatment they are prone to progression, and are often the cause of disability.

  • Rheumatoid arthritis.The defeat is usually bilateral. With minimal activity of the autoimmune process, pain is weak or moderate, intermittent, pulling, pressing, accompanied by morning stiffness. With moderate activity, the patient complains of periodic prolonged aching, pressing or bursting pains of moderate intensity, not only during movement, but also at rest. There is stiffness for many hours, moderate recurrent synovitis. With high activity of rheumatoid arthritis, the pain is strong, diffuse, exhausting, wavy in nature, increases in the pre-morning hours. Stiffness becomes constant, a large amount of fluid accumulates in the knees, contractures form over time.
  • Systemic lupus erythematosus.Arthralgias are often symmetrical, although one joint may be affected. They can occur at any stage of the disease; with a recurrent course of SLE, they resemble rheumatoid arthritis. With low activity of the process, pain is short-term, non-intense, local, aching, pulling. In severe cases, the pain syndrome progresses, the pain is wavy, disrupts the night's sleep, becomes prolonged, diffuse, increases with movement, combined with synovitis, edema, hyperemia.
  • Rheumatism.Joint pain is one of the first manifestations of rheumatic fever, appears 5-15 days after an acute infection, affects several joints at once (usually paired). The pains are rather short-lived, but intense, migrate from one joint to another, differ in nature from pulling or pressing to burning or pulsating. The knees are swollen, hot, the skin over them is reddened. Movement is severely limited. After a few days, the severity of pain decreases, movements are restored. In some patients, residual effects in the form of moderate or mild dull pain persist for a long time.
  • Reactive arthritis.More often occurs 2-4 weeks after intestinal and urogenital infections, usually affects one or two joints of the lower extremities, combined with urethritis, conjunctivitis. The development of reactive arthritis is preceded by increased urination, pain and burning sensation in the urethra, lacrimation, and cramps in the eyes. Pain in the knee is strong or moderate, constant, wavy, aching, pulling, twitching, combined with limitation of movement, deterioration of the general condition, fever, severe swelling and redness of the affected area. Painful sensations and signs of inflammation persist from 3 months to 1 year, and then gradually disappear.

Degenerative-dystrophic processes

They develop as a result of metabolic disorders in the structures of the joint and periarticular soft tissues. They have a chronic course, progressing over many years. Often accompanied by the formation of calcifications, cysts and osteophytes, deformation of the knee surface. With significant destruction of the articular surfaces, they lead to pronounced impairment of movement and support function, become the cause of disability, and require the installation of an endoprosthesis.

  • Osteoarthritis.It develops for no apparent reason or against the background of various injuries and diseases, mainly in older and middle-aged people. At first, the pain is weak, short-term, usually pulling or aching, occurs with prolonged exertion and disappears at rest, often accompanied by a crunch. Gradually the pain syndrome intensifies, the knees begin to ache "in the weather" and at night, there is a limitation of movements. Distinctive features of gonarthrosis are starting pains (it hurts until you "disperse"), periodic attacks of sharp cutting, burning or shooting pains due to the blockade. During periods of exacerbation, synovitis often occurs, in which the pain becomes constant, pressing, bursting.
  • Meniscopathy. . . Usually detected in athletes, people whose work involves significant loads on the knee joint. Manifested by one-sided local deep pain inside the knee at the level of the joint space, more often in the outer half of the knee. The pain intensifies during movement and subsides at rest, it can be dull, pressing or pulling. With progression, there are acute shooting pains when trying to move. On the anterolateral surface of the joint in the projection of pain, a small painful formation is sometimes felt.
  • Tendopathies. . . Tendons near the knees are affected. At the initial stage, they are manifested by short-term local superficial pain at the peak of physical activity. Subsequently, painful sensations arise with moderate, and then light loads, limit the usual daily activity. The pain is pulling or aching, directly related to active movements, is not detected during passive extension and flexion of the knee, sometimes accompanied by a crunch or crackle. In the area of the lesion, it is possible to probe the site of greatest pain. Local signs of inflammation (edema, hyperemia, hyperthermia) are insignificant or absent.
  • Osteochondropathy.Children and young people are more often affected, the duration of the disease is several years. Usually they begin gradually with mild lameness or intermittent, non-intense dull pains, aggravated by exertion, disappearing at rest. With the progression of osteochondropathy, the pain becomes strong, constant, pressing, burning or baking, accompanied by severe lameness, limitation of movement and difficulty in resting on the limb. Then the pain gradually decreases, the support function is restored.
  • Chondromatosis.Usually diagnosed in older men, less often in infants. Chondromatosis of the joints is manifested by moderate dull wave-like pains, often worsening at night and in the morning. Movement is limited, accompanied by a crunch. Sometimes blockages occur, characterized by sudden sharp shooting pain, impossibility or severe limitation of movement. With the development of synovitis, pains acquire a bursting character, combined with an increase in knee volume, swelling of soft tissues, and a local increase in temperature.
Disorders of metabolic processes in the structures of the joint can provoke pain in the knee

Tumors and tumor-like formations

Pain syndrome can be caused by a cyst, a benign or malignant tumor that directly affects the joint or periarticular tissues. In addition, knee pain can serve as an alarming signal of hypertrophic arthropathy, paracancrotic polyarthritis - paraneoplastic syndromes characteristic of lung cancer, breast cancer and other oncological processes.

  • Baker's cyst.Represents a hernial protrusion in the popliteal fossa. In the initial stages, it manifests itself as unpleasant sensations or mild local pain along the back of the knee. Against the background of an increase in Baker's cyst due to compression of nearby nerves, burning or shooting pains, numbness or tingling in the sole area may appear. Symptoms are worse when trying to flex the knee as much as possible. In the popliteal fossa, an elastic, slightly painful tumor-like formation is sometimes felt.
  • Benign tumors.Includes chondromas, osteochondromas, nonossifying fibromas and other neoplasms. They are characterized by a prolonged asymptomatic or low-symptom course, they can manifest themselves with vague and intermittent local non-intense pain. With large neoplasias, a solid formation is felt, sometimes synovitis develops.
  • Malignant neoplasias.The most common malignant tumors affecting the joint area are synovial sarcoma, osteosarcoma, and chondrosarcoma. They manifest with dull local vague pains, sometimes with a certain circadian rhythm (worse at night). The intensity of pain increases, they become sharp, cutting, burning or twitching, spreading along the knee and adjacent tissues, accompanied by deformation, edema, synovitis, expansion of the saphenous veins, violation of the general condition, the formation of contracture. When palpating, a painful tumor-like formation is determined. When the process is started, the pain is excruciating, unbearable, exhausting, deprives of sleep, and is not eliminated by non-narcotic analgesics.

Invasive operations and manipulations

Pain syndrome is triggered by damage to the knee tissue during invasive procedures. The severity of pain directly depends on the trauma of manipulations on the knee joint. With the penetration of pathogenic microbes into the joint area, pain is caused by inflammatory changes.

  • Manipulation.The most common procedure is puncture. Pain after puncture is short-term, not intense, quickly subsiding, localized in the projection of the puncture, which is usually performed on the outer surface of the knee. After a biopsy, the pain may be twitching at first, then become dull and disappear after a few days.
  • Operations.After arthroscopy, the pain is moderate, at first quite acute, then dull, subsiding after a few days or 1-2 weeks. After arthrotomy, the pain syndrome is more intense, it can persist up to several weeks due to significant tissue damage. Usually, in the first 2 or 3 days after the interventions, patients are prescribed analgesics, then the pain becomes weak and gradually disappears.

Psychosomatic conditions

Sometimes arthralgia in the knees occurs in the absence of an organic basis (trauma, inflammation, destruction, etc. ) under the influence of psychological factors. It is believed that such pain plays a protective role, as it helps to reduce emotional stress by transforming experiences into physical sensations. A distinctive feature of such pains is their indefinite nature, inconsistency, the absence of visible changes, a clear connection with physical activity and other objective provoking factors. Meteopathic arthralgias are observed in people who are sensitive to changes in atmospheric pressure.

In addition, irradiation of pain to the knee is possible with coxarthrosis, lumbar osteochondrosis, Perthes disease, fibromyalgia, sciatic nerve neuropathy. However, with these pathologies, pain syndromes of other localization usually come to the fore. Additional risk factors that increase the likelihood of injury and disease of the knee joint include excess weight, professional sports, hypovitaminosis, metabolic disorders, and old age. Hypothermia, stress, physical exertion, and diet disturbances can be provoking factors for exacerbation of chronic pain.


The diagnostic search algorithm is based on taking into account the nature of the pain syndrome, its duration, identifying concomitant symptoms and events preceding the onset of knee pain. At the initial visit to a doctor (traumatologist-orthopedist, surgeon, rheumatologist), a visual examination and palpation of the knee, assessment of the volume of active and passive movements are performed. Taking into account the data obtained, in the future, the patient can be assigned:

  • Laboratory blood tests. . . A complete blood count helps to identify hematological changes characteristic of an acute infectious and inflammatory process (leukocytosis, increased ESR), eosinophilia, typical of an allergic reaction. Biochemical and serological studies are most informative for autoimmune diseases, which are characterized by the formation of specific acute phase proteins and immunoglobulins (CRP, rheumatoid factor, ASL-O, CEC, antibodies to DNA, etc. ).
  • Radiography.The basic diagnostic method is X-ray of the knee joint in 2 projections. The presence of pathology is indicated by changes in the contours of the articular head and cavity, narrowing of the joint space, changes in the thickness of the end plates, the presence of edge defects in the articular ends of the bones, osteolysis and bone destruction. In some diseases (meniscus injury, Baker's cyst), contrast arthrography demonstrates the greatest sensitivity.
  • Arthrosonography. . . Knee ultrasound is a fast, inexpensive, affordable and highly informative diagnostic method. Allows you to judge the presence of effusion and free bodies in the joint cavity, to identify damage and pathological changes in the periarticular soft tissues (signs of calcification, hemorrhage, etc. ). They help to differentiate with high accuracy the etiology of joint pain.
  • CT and MRI. . . They are the methods of choice for arthropathy of any genesis. They are used for a more detailed assessment of the nature and degree of pathological changes, to identify signs typical of traumatic, inflammatory and tumor lesions of bone structures and soft tissues. CT and MRI of joints are usually used with limited information content of other instrumental studies.
  • Joint puncture. . . It is performed when there is an indication of the accumulation of exudate or transudate in the joint capsule. As part of the differential diagnosis of inflammatory, degenerative and neoplastic diseases, a cytological, bacteriological or immunological study of the synovial fluid is performed. To establish the diagnosis of autoimmune damage to the knee joint, tuberculous arthritis, synovioma, it is extremely important to conduct a biopsy of the synovium.
  • Arthroscopy. . . The purpose of invasive endoscopic diagnostics can be biopsy sampling, clarification of the necessary diagnostic information during a visual examination of joint elements. In some cases, diagnostic arthroscopy develops into a therapeutic one (atroscopic removal of intra-articular bodies, meniscectomy, autoplasty of ligaments, etc. ).
Knee arthroscopy to diagnose knee pain

Symptomatic treatment

Treatment of the causes of knee pain is carried out differentially, taking into account the identified disease. At the same time, symptomatic care is an essential part of a comprehensive treatment process aimed at reducing discomfort and improving the quality of life. Immediately after the injury, it is recommended to apply a cold compress to the knee area - this will help reduce pain sensitivity. Ethyl chloride has a local cooling and anesthetic effect. In all cases, resting the knee helps to reduce soreness. It is necessary to limit movements, give the leg a position in which the pain is minimal. When walking, a fixation bandage is applied to the knee; immobilization of the limb with the help of a plaster splint is possible.

In the acute period of injury or illness, it is strictly forbidden to massage the knee, apply warming compresses, and wear high-heeled shoes. The main classes of drugs used for the symptomatic treatment of pain and inflammation are analgesics and NSAIDs in the form of ointments, tablets and injections. The listed measures can only temporarily reduce pain, but do not eliminate the root cause of arthralgia. Therefore, all cases of knee pain require qualified diagnosis and treatment, and some conditions (fractures, dislocations, hemarthrosis) require emergency medical care. You cannot postpone a visit to the doctor if the pain is combined with a change in the shape of the knee (swelling, smoothing of the contours, asymmetry), the inability to perform flexion-extensor movements, ballot of the patella, impaired support of the limb.