Generality
The varus knee is an anatomical deformity of the lower limbs, in the presence of which the knees point one in the opposite direction to the other.
Among the causes of knee launching, the following certainly deserve a mention: rickets, metabolic bone diseases, gonarthrosis, Blount's disease, repeated and poorly treated knee ligament injuries, fractures of the femur or tibia that are poorly consolidated and bone infections.
The mild forms of a knee launch are asymptomatic and without repercussions in everyday life; the most serious forms, on the other hand, are painful and responsible for various complications, mainly affecting the ligaments of the knee and the medial meniscus of the knee.
As a rule, the diagnosis of a varus knee is immediate and is based on simple observation of the lower limbs.
Individuals with a varus knee undergo treatment only when the deformity of which they are carrying is responsible for irreconcilable symptoms with a normal life.
Short anatomical reference of the knee
The knee is the important synovial joint of the human body, placed between the femur (superiorly), tibia (inferiorly) and patella (anteriorly).
Several anatomical elements take part in its constitution, including:
- Articular cartilage . Located on the lower surface of the femur, it serves to protect the latter from friction damage.
- The synovial membrane . It covers the joint from the inside and produces a lubricating fluid, called synovial fluid . Synovial fluid reduces friction between the various components of the joint complex.
- A series of tendons and ligaments . They are essential in guaranteeing the right stability to the joint, during the movements of the lower limb, and in ensuring the appropriate alignment between the femur and tibia. Their correct functioning is, in part, linked to the lubricating action of the synovial fluid.
- The synovial bags . They are small synovial membrane pockets, filled with synovial fluid. They have a lubricating function and anti-rubbing function.
- The internal meniscus (or medial meniscus ) and the external meniscus (or lateral meniscus ). Consisting of cartilage and located on the upper surface of the tibia, the two menisci provide stability to the joint and protect the tibia from the stresses coming from the femur, during movements of the lower limb.
With its position and its structural components, the knee plays a fundamental role in supporting the weight of the body and in allowing the movements of extension and flexion of the leg, during a walk, a run, a jump etc.
What is the knee launching?
The varus knee is the anatomical deformity of the lower limbs, due to which the two knees point outwards, ie in the opposite direction to each other.
In common parlance, the launching knee is that condition also known by the terms " knees in O ", " bow knees " or " knees in parentheses ". As can be seen from the figures to the side, to justify the use of the aforementioned words is the aspect that the lower limbs assume, in people with varus knees: there is indeed a similarity with the vowel O, with an arc or with a pair of round brackets.
Causes
The varus knee is an example of failure to align the femur and tibia .
In fact, if we observe the lower limbs of a person with arched knees, it is possible to notice how femurs and shins give life, in a medial position, to an obtuse angle, instead of the physiological flat angle.
Therefore, at the base of the varus knee, there is a defect of angulation between the femurs and the tibiae.
The main causes and risk factors of the knee launch are:
- The rickets ;
- Metabolic bone diseases (eg, Paget's disease);
- Blount's disease, also known as the varus tibia ;
- Fluorine or lead intoxication ;
- Some neurological disorders ;
- Osteoarthritis, a condition that, when it concerns the knee, is called gonarthrosis ;
- Repeated and poorly treated knee ligament injuries ;
- Malformed fractures of the femur or tibia ;
- Bone infections that have altered normal skeletal development;
- Some forms of skeletal dysplasia ;
- The presence of an evolutionary disorder;
- Hereditary predisposition to knee launch.
Knee launch in the child
In children under 18 months, the varus knee is a very common deformity. However, in most cases, it is a temporary problem, due to age, which disappears when the subjects begin to walk.
The bipedal displacement, in fact, changes the burden of body weight on the knees and this has the effect of spontaneously correcting the incorrect angle between the femur and tibia, typical of the varus knee.
The non-resolution of the knee, in a child older than 18 months, or a possible aggravation of it, represent two alarm bells, which could indicate the presence of some causal factors previously exposed, including: rickets, the Blount's disease and a metabolic bone disease.
Review of the anatomical meaning of the terms "medial" and "lateral"
In anatomy, medial and lateral are two terms of opposite meaning, which serve to indicate the distance of an anatomical element from the sagittal plane . The sagittal plane is the anteroposterior division of the human body, from which two equal and symmetrical halves are derived.
Mediale means "near" or "closer" to the sagittal plane, while lateral means "far" or "farther" from the sagittal plane.
Epidemiology
The varus knee is a very common deformity among soccer players, who dedicate themselves to the latter since adolescence.
According to the experts, the high incidence of the knee between players would be linked to the most typical gesture of football: kicking the ball. Repeatedly kicking the ball, in fact, would create an imbalance between the inner thigh and outer muscles (with the former becoming stronger than the latter), such that, little by little, the femur loses physiological alignment with the tibia .
Symptoms
The launching knee tends to be a problem exclusively of an aesthetic nature; if, however, the knees point markedly towards the outside, its presence can also be symptomatic .
The possible symptoms of a severe knee launch are:
- Generalized knee pain;
- Ambulation abnormalities, which involve the functional overload of some specific anatomical elements of the knee. In particular, the functional overload of the medial meniscus is noted, a condition which, if not treated properly, can give rise to various complications, including the rupture of the medial meniscus itself .
The typical clinical manifestations of rupture of the medial meniscus are: pain in correspondence with the medial meniscus, sense of stiffness in bending the affected knee and emission of crunches, after certain movements of the joint;
- Instability and / or reduced mobility of the knees . They are two clinical manifestations that may depend on strains or small fraying of one or more ligaments of the knee. The anterior cruciate ligament and the lateral collateral ligament are reported among the knee ligaments which suffer most from the presence of the knees in parentheses;
- Pain in the muscles of the lower limbs . It is probably due to the excessive misalignment between the femur and tibia.
When should I go to the doctor?
The carriers of the knee should contact an orthopedist, expert in knee diseases, in all those situations where they complain of severe pain and, because of the latter, they have serious difficulties in carrying out the most normal daily activities (eg: climbing stairs, driving a vehicle etc.).
Complications
Injuries such as rupture of the meniscus (lateral or medial) and fraying of one of the knee ligaments are factors that favor the development, generally at a later age, of conditions such as chondromalacia of the patella (or chondromalacia rotulea ) and osteoarthritis of the knee (or gonarthrosis ).
Both the chondromalacia of the patella and the osteoarthritis of the knee are two diseases of the articular cartilage, which lead to degeneration.
Diagnosis
The diagnosis of a varus knee is simple and immediate. It is sufficient, in fact, to observe the lower limbs of a bearer of the deformity in an upright position and to ascertain that:
- The two knees point one in the opposite direction of the other;
- The two femurs tend to have a divergent pattern, starting from the hip;
- When the ankles come into contact, the space that separates the two knees is several centimeters.
The use of more in-depth diagnostic investigations - and among these the physical examination, the anamnesis, the blood tests and the magnetic resonance in the knees deserve a mention - allows the doctors to establish the precise causes of the knee launch.
Therapy
Doctors believe that the launching knee should be subjected to specific care only when it is responsible for a certain symptomatology and strongly affects the quality of life of the wearer.
In the absence of symptoms, therefore, they consider it superfluous to resort to any form of therapy, even the least invasive.
Treatment options: conservative therapy and surgery
In the presence of a symptomatic varus knee, the first therapeutic choice of the doctors falls, almost always, on a conservative treatment .
Therefore, if and only if such treatment should prove ineffective, surgery is expected.
CONSERVATIVE TREATMENT
The conservative treatment of the varus knee mainly involves:
- The use of ad hoc orthopedic and orthopedic shoes ;
- Physiotherapy exercises, aimed at: strengthening the thigh muscles with a role in the physiological alignment between the femur and tibia, and improving the elasticity of the knee ligaments;
- Exercises of postural gymnastics, whose purpose is to remedy the functional overload of some portions of the knee (remember that the launching knee represents a danger to the health of the medial meniscus).
- The administration of chondroprotectors and anti-inflammatories ;
- Hyaluronic acid injections ;
- Reduction of body weight (this applies, of course, only if the patient is an obese person).
The effectiveness of conservative therapy depends on the degree of severity of the varus knee: the more severe it is, the less are the chances that the aforementioned therapeutic remedies entail tangible benefits.
SURGERY
The surgery for the treatment of the varus knee consists of a femoral osteotomy operation.
The femoral osteotomy is a delicate surgical practice, which involves the remodeling of the distal portion of the femur, so as to establish a physiological relationship between the femur itself and the tibia.
In light of this, in practicing the femoral osteotomy in a varus knee carrier, the treating orthopedist acts on the femur with the intention of aligning it to the tibia and eliminating the obtuse angle, which the two aforementioned bones form along the medial side lower limb.
If the femoral osteotomy is successful, situations such as the functional overload of the medial meniscus, generalized knee pain, etc. they should resolve.
Prognosis
Thanks to advances in medicine, both in the field of conservative remedies and in the surgical field, today the varus knee is a problem that can be overcome with good results and a favorable prognosis.
