traumatology

Water in the knee - Spill to the knee

Generality

The so-called knee fluid is a sign of pain in the joint, which may depend on trauma, such as the rupture of a meniscus, or particular pathological circumstances, such as rheumatoid arthritis.

The knee reacts to such insults by producing an excess of "liquid", the accumulation of which makes the articulation more or less swollen, rigid in movements and painful; furthermore, if not treated properly, it can have serious consequences.

The presence of fluid inside the knee requires a precise diagnosis of the responsible causes, because only in this way is it possible to adopt the most appropriate therapies. Depending on the case, the treatments may consist of simply resting the joint, taking anti-inflammatory drugs and / or resorting to medical-surgical interventions.

Short anatomical reference: the knee

The articulation, or articular capsule, of the knee is placed between the femur (superiorly), the tibia (inferiorly) and the patella (anteriorly), and is formed by different elements, all equally important in allowing the movement and in supporting the weight of the human body . Among these, remember:

  • The articular cartilage, which covers the bone ends and prevents rubbing.
  • The synovial membrane, which internally covers the capsule and produces a lubricating fluid, called synovial fluid ; this liquid reduces friction between the femur and tibia and facilitates the movement of the entire joint complex.
  • Tendons and ligaments, which allow flexion of the lower limb (during a walk, a run, etc.) and provide stability to the joint. Their lubrication is guaranteed by the presence of synovial fluid.
  • The synovial bags, which are small pockets separated from the main synovial membrane, but also containing a small amount of synovial fluid. They help keep tendons and ligaments lubricated.
  • The two meniscuses, the lateral (or external meniscus ) and the medial (or internal meniscus ). Both are structures made of cartilage, located in the upper part of the tibia; they provide stability to the joint (such as tendons and ligaments) and absorb the stresses that the femur and the rest of the body impress on the tibia itself.

What is the liquid in the knee

The excessive accumulation of fluid around the articular structures of the knee represents a response of the joint to traumas or to particular pathological conditions. The expression "liquid in the knee" is in any case improper; the doctors, in fact, define this accumulation with the term " pouring to the knee "; moreover, the liquid can be serous (in this case we speak of hydrartre ) or contain traces of blood ( hemarthros ).

Causes

The formation of fluid in the knee can occur either as a result of traumatic events, such as a strong contusion, or as a result of particular pathological states, which can affect the entire organism or the knee joint alone.

TRAUMAS AND CONTUSIONS

The fluid in the knee may be due to traumas and bruises, which damage the main structures of the joint.

The typical traumas responsible for knee spills are: fracture of the kneecap, rupture of a meniscus, rupture or stretching of a ligament and rupture or inflammation due to overloading of a tendon; therefore even minimal trauma but repeated over time can cause a spill.

Ligaments and tendons of the knee subject to breakage, stretching and inflammation

The ligaments of the knee which, due to a trauma, can undergo breakages or strains are: the anterior cruciate ligament, the posterior cruciate ligament, the medial collateral ligament (or internal) and the external collateral ligament.

The tendons of the knee that can break or become inflamed most often are: the patellar tendon, the quadriceps muscle tendon and the popliteal tendon.

DISEASES AND PATHOLOGICAL CONDITIONS

The unusual accumulation of fluid in the knee may be the reaction to a disease that affects the entire organism or the response to a circumscribed pathological condition, which concerns exclusively the articular structures.

The diseases and conditions of pathological type that most frequently lead to the formation of fluid in the knee are shown in the following table:

Diseases affecting the entire body

  • Osteoarthritis (or arthrosis )
  • Rheumatoid arthritis
  • Gout (monosodium urate crystal deposition disease)
  • Pseudogout (calcium pyrophosphate dihydrate deposition disease)
  • Diseases characterized by an alteration in blood coagulation (eg haemophilia )
  • Tuberculosis (rare lung disease in Italy) and syphilis (sexually transmitted disease)

Pathological conditions of a local nature

  • A knee bursitis, or the inflammation of one of the joint bags
  • A knee cyst (for example, a Baker cyst )
  • A knee infection
  • Some tumors (for example a tumor of the synovial membrane of the joint, also known as synovioma )

RISK FACTORS

The people most prone to the formation of fluid in the knee are:

  • Individuals of middle age or advanced age (generally aged 55 and over), as they are also the most predisposed subjects to osteoarthritis and rheumatoid arthritis (NB: there are also juvenile forms of rheumatoid arthritis).
  • Practitioners of sports, such as football, rugby and basketball, in which there are frequent changes of direction (which continuously stress the articular structures of the knee) and contact traumas.
  • Those who are overweight or suffer from obesity, as the knees (especially the articular cartilages) must bear a high weight, which in the long run will lead to wear and degeneration.
  • Patients in anticoagulant therapy : as they are predisposed to bleeding, even in the joints; therefore, even a minor trauma to the knee joint could result in hemarthrosis.

Symptoms and Complications

There are three signs and symptoms that characterize the knee fluid: swelling, joint stiffness and pain.

The swelling, which can be appreciated by comparing the two knees (the healthy with the "sick"), can be more or less evident, depending on the joint problem underlying the payment. With few exceptions, a very swollen knee is usually synonymous with a serious situation.

Joint stiffness is the inability, due to the bulk created by the excess liquid, to bend and / or extend the knee completely.

Finally, pain is a very variable sensation, which generally depends on the severity of the trigger. In cases of very intense pain, the suffering individual may also have difficulty standing up.

WHEN TO REFER TO THE DOCTOR?

It is advisable to request a medical consultation when:

  • The classic remedies, such as ice packs, rest and local painkillers, are ineffective against pain, joint stiffness and swelling.
  • The sore knee becomes red and, to the touch, is warmer than the healthy knee.

COMPLICATIONS

The fluid in the knee is a circumstance that should not be overlooked, since, if it is caused by a serious illness or a very serious trauma, it can strongly compromise the mobility and, in some cases, also the stability of the joint. Indeed, if at the origin of the problem there was an infection, the joint structures (primarily the cartilages) could undergo a process of complete degeneration.

Diagnosis

In order to put the right remedy to the fluid in the knee (whose presence is easily seen even with the naked eye), an extremely accurate diagnosis of the causes is needed.

In general, the starting points are the physical examination (ie the analysis of the signs and symptoms, their intensity and their appearance) and the examination of the clinical history (ie the analysis of the patient's health conditions) : in fact, based on the characteristics of the symptoms and those of the patient, the doctor is able to establish which are the most correct diagnostic tests for a deepening of the situation.

DIAGNOSTICS FOR IMAGES

Imaging tests are performed if the doctor suspects a bone fracture, a cartilaginous degeneration (due, for example, to arthrosis) or a problem with the ligaments or tendons. These exams consist of:

  • X-rays . They clearly show the bone fractures of the patella and the results of cartilage degeneration, due for example to arthrosis or rheumatoid arthritis.
  • Ultrasound . It is a rapid, non-invasive examination that shows the exact position of the liquid (for example, if it is near a bag or near the synovial membrane), but not damage to meniscuses and / or ligaments.
  • Nuclear magnetic resonance (RMN) . It is the ideal test to view the state of health of tendons, ligaments and meniscuses. Indeed, MRI shows the entire joint structure in great detail.

BLOOD TESTS

Examinations of a blood sample taken from an arm are expected if the doctor suspects an infection, an inflammation, rheumatoid arthritis, Lyme disease, a coagulation disorder (eg haemophilia), the gotta or pseudogout.

In fact, all these diseases or pathological conditions release characteristic traces in the blood.

ARTHROCENTES FOR DIAGNOSTIC PURPOSE

Arthrocentesis consists in aspirating the excess liquid, present in the knee, and analyzing it later in the laboratory.

If there are:

  • Blood cells, means that there has been a trauma or a coagulation disease is in progress (in this second case, blood tests are essential to clarify the situation).
  • Bacteria means an infection is in progress.
  • Monosodium urate or calcium pyrophosphate dihydrate crystals mean that the patient suffers from gout or pseudogout, respectively.

DIAGNOSTIC PURPOSE ARTHROSCOPY

Arthroscopy for diagnostic purposes is a minimally invasive surgical procedure, which is carried out when previous examinations have been poor in useful information and the situation still has some question marks.

From the practical point of view, it consists in observing from the inside the painful joint, through an instrument equipped with a camera and a light source, called arthroscope .

Treatment

Only once the exact causes and precise characteristics of the fluid in the knee have been established can therapy begin. The latter, in fact, is chosen based on the origin of the joint problem and its severity.

Therapeutic treatments can be both pharmacological and medical-surgical. Medical-surgical interventions include arthrocentesis for therapeutic purposes, therapeutic arthroscopy and knee prosthesis operation.

PHARMACOLOGICAL TREATMENTS

Adopted in many situations, both serious and less serious, drug therapy consists of:

  • Pain-relieving drugs with anti-inflammatory power . They serve to moderate pain and inflammation, providing relief to the patient. Among the most widely used medicines in this category are paracetamol and NSAIDs (Non-Steroidal Anti-Inflammatory Drugs).
  • Antibiotics . They are used when the diagnosis has established that a bacterial infection is in progress (ie bacteria-supported). Antibiotic therapy, if completed, causes a gradual attenuation of the typical symptoms of the fluid in the knee, namely swelling, pain and stiffness.
  • Corticosteroid drugs . They are effective and powerful anti-inflammatories that, however, given their numerous side effects, are only administered in cases of extreme necessity and when paracetamol or NSAIDs have had little effect.

ARTHROCENTES FOR THERAPEUTIC PURPOSE

The therapeutic arthrocentesis is performed with the same modalities of the arthrocentesis for diagnostic purposes, with the only difference that, in the first case, the objective is to eliminate most of the liquid present within the joint.

After aspiration, the doctor may consider it appropriate to inject a dose of corticosteroid drugs, with an anti-inflammatory or hyaluronic acid action in cases of arthrosis.

ARTHROSCOPY FOR THERAPEUTIC PURPOSE

Arthroscopy for therapeutic purposes differs from diagnostic arthroscopy due to the fact that, during surgery, the surgeon uses, in addition to the arthroscope (which thanks to the camera is fundamental for orientation within the joint), of the others precision instruments, specifically designed to fix joint damage.

The damage most commonly remedied by arthroscopic surgery is rupture of the meniscus, anterior cruciate ligament and patellar tendon.

Arthroscopy synoviectomy involves the surgical removal of part of the synovial membrane and is one of the optional treatments for severe rheumatoid arthritis or recurrent hemarthrosis.

KNEE AND SINOVIECTOMY PROSTHESIS INTERVENTION

The intervention of knee prosthesis is a very invasive surgical operation, which is practiced only in very serious cases and when the above-mentioned treatments have been ineffective.

TWO FUNDAMENTAL NATURAL REMEDIES: THE REST AND THE ICE

In the case of a swollen, painful and stiff knee, the ice combined with the elevation of the suffering limb and rest represent two excellent natural remedies, as they guarantee relief and a sensitive attenuation of the symptomatology. Furthermore, they are devoid of side effects and are very cheap.

Thanks to ice and to rest, the pour can be reabsorbed spontaneously when it is modest.

cryotherapy

Ice packs are one of the most representative treatments of the so-called "cold cure", or cryotherapy . The latter has powerful analgesic effects (ie against pain), as it slows the transmission of painful and anti-edema impulses (ie against edema or swelling), since it prevents the extravasation of blood in the surrounding tissues.

Prevention

To prevent the formation of fluid in the knee, it is advisable to:

  • If you suffer from osteoarthritis, rheumatoid arthritis, gout or pseudogout, undergo frequent medical examinations, so as to monitor the state of the joints.
  • Wear the protections and braces prescribed by your doctor, if you have been involved in a serious knee injury in the past.
  • Strengthen the thigh muscles, however, according to the instructions of an experienced physiotherapist (NB: this advice is aimed primarily at those who carry out a sport activity and want to prevent knee injuries).
  • Maintain a normal body weight, so as to avoid an overload on the knee joint.
  • Treat yourself according to the doctor's instructions, if you suffer from one of the pathologies that cause the formation of fluid in the knee.