Generality
The valgus knee is an anatomical deformity of the lower limbs, in the presence of which the knees point towards each other.
The causes of the valgus knee include: the inadequacy of some hip muscles (the buttocks) and the thigh (the vastus medialis, the semimembranosus and the semitendinosus), a reduced capacity for dorsiflexion of the ankle and, finally, a predisposition anatomical to the problem in question.
The mild forms of the valgus knee are asymptomatic and have no repercussions in everyday life; the most serious forms, on the other hand, are generally painful and responsible for various complications, affecting the ligaments of the knee, the lateral meniscus of the knee, etc.
As a rule, the diagnosis of valgus knee is immediate and is based on simple observation of the lower limbs.
People with valgus knees are treated only when the deformity 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 pockets of synovial membrane, filled with liquid. 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 worth?
Knee valgus is the term that, in the medical field, indicates the anatomical deformity of the lower limbs whereby the two knees point inwards, that is, towards each other.
Due to the particular orientation towards the inside of the two knees, the valgus knee is also called " knee to X " or " knees to X ": the upper part of the X represents the femurs of the two legs; the center of the X represents the two knees oriented towards each other; finally, the lower part of the X represents the two tibiae and the two fibulae (NB: tibia and fibula are the two bones that form the skeleton of a leg).
The valgus knee is the anatomical deformity of the lower limbs opposite to the so-called varus knee, in which the two knees point outwards, that is each in the opposite direction to the other.
Another synonym of knee valgus; meaning of medial and lateral
Another way to indicate the valgus knee is the wording " medial displacement of the knee ".
In anatomy, the term "medial" means "near" or "closer" to the sagittal plane, ie the anteroposterior division of the human body, from which two equal and symmetrical halves are derived.
It is opposed to the term "lateral", which instead means "far" or "farther" from the sagittal plane.
Mono- or bilateral deformity?
When we talk about the valgus knee, we usually refer to a bilateral deformity. However, it is good to remind readers that there are also cases of unilateral valgus knee, that is to say that they involve only one knee.
Causes
The valgus knee reflects the lack of physiological alignment between the femur and tibia : if in an individual without skeletal deformities the two femurs and the two tibiae are almost totally perpendicular to the supporting plane, in a subject with X-knees the two femurs appear converge at the level of their distal ends and the two tibiae tend to distance themselves from each other as they descend towards the feet.
From the observation of the lower limbs of a person with X-knees emerges, immediately, that femurs and tibias, with their particular orientations, give rise to an obtuse angle, laterally, and at an acute angle, medially (NB: in a person with knees without deformity, the femur and tibia form a flat angle).
In the adult human being, the lack of alignment between the femur and tibia that characterizes the valgus knee may depend on at least 5 factors:
- The weakness of the hips, due to inadequate gluteal musculature, not strong enough .
The small, medium and large gluteal muscles contribute to the alignment of the femur with respect to the tibia, acting at the level of the hip, with a force that pushes outwards. After all, it is the muscles that allow the external abduction of the hip.
With the action of pushing outwards, imposed by the gluteal muscles, the portion of the femur that constitutes the hip tends to change angle and to orient itself towards the inside, ie towards the other leg. The muscles with opposite action to the gluteus muscles, or the adductor muscles of the hip, also contribute to the change of orientation.
- Reduced ankle capacity to perform dorsiflexion movement . Dorsiflexion is the movement that allows you to lift your foot and walk on your heels.
Due to the reduced capacity of dorsiflexion of the ankle, due to compensation, an anomalous pronation of the foot emerges, which has three effects consequent to one another: the rotation towards the inside of the tibia → the rotation towards the inside of the hip → hip adduction.
At the end of everything, there is a misalignment between the femur and tibia, with the knee pointing towards the inside of the lower limb.
- The particular weakness of the vastus medialis muscle of the quadriceps femoris (anterior thigh muscle complex) . The vastus medialis muscle contributes to the alignment of the femur with respect to the tibia, with a pushing action on the medial side of the knee. If it is weak, the aforementioned pushing action is compromised.
- The particular weakness of the semimembranosus and semitendinosus muscles of the hamstring (posterior muscular complex of the thigh) . The semimembranosus and semitendinous muscles act on the alignment of the femur with respect to the tibia in the same way as the vastus medialis muscle of the femoral quadriceps. Therefore, if they are weak, the knee tends toward the other knee, creating a misalignment between the femur and the tibia.
- An anatomical predisposition to the misalignment of the femur compared to the tibia, with consequent movement of the knee towards the knee of the other leg . The presence of a valgus knee may depend on the width of the pelvis, a structural abnormality of the knee, the abnormal shape of the femur or tibia, some deformity of the foot or, finally, a deformity of the hip.
The valgus knee can be considered the result of a defect of angulation between the femur and tibia, with the first pointing markedly inwards and the second which, instead, points considerably towards the outside.
Conditions favoring the valgus knee
According to reliable medical studies, conditions such as: rickets, skeletal dysplasia, obesity and a history of skeletal infections or traumas that have altered, in some way, the normal development of the femur and tibia, would favor the presence of the knee.
Epidemiology
The valgus knee is a fairly common condition in children up to the age of 5-6; in these situations, however, it is almost always a temporary deformity, which resolves spontaneously around 7-9 years, due to the normal process of bone growth.
In the adult population, the valgus knee is particularly common among women, due to the particular shape of the female pelvis (or pelvis ).
Symptoms and Complications
The valgus knee tends to be an exclusively aesthetic problem; if, however, the knees point markedly towards each other, its presence can also be symptomatic .
The possible symptoms of a severe valgus knee are:
- Patellar pain, ie pain in the patella ;
- Ambulation abnormalities, which involve the functional overload of some specific anatomical elements of the knee. In particular, the functional overload of the lateral meniscus is noted, a condition which, if not adequately treated, can give rise to various complications, including the rupture of the lateral meniscus itself .
The typical clinical manifestations of rupture of the lateral meniscus are: pain in correspondence with the lateral meniscus, a sense of stiffness in bending the affected knee and the release of crunches, after certain movements of the joint;
- Instability and / or reduced mobility of the knee . 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 medial collateral ligament are reported among the knee ligaments that suffer most from the presence of X-knees;
- Pain in the outside of the knee, which tends to increase with the flexing movement of the leg. This painful sensation derives from an inflammatory process against the so-called iliotibial band, an inflammatory process which, in the medical field, is also known as " iliotibial band syndrome " or " runner's knee ".
When do you notice most?
In resting conditions (standing position), some forms of valgus knees are more visible than others; this is possible simply because, in the aforementioned circumstances, the displacement in the internal (or medial) direction of the knees is more pronounced.
That being said, performing some movements and taking some postures with the body show the knee to be worth it in anyone who is a carrier, even if it is in mild form. For example, they clearly denote the presence of X-knees of certain gymnastic exercises that are very popular among those who practice sports, such as: normal squats, jumping squats and lunges.
Complications
Injuries such as rupture of the meniscus (lateral or medial) and fraying of one of the ligaments of the knee, are factors that favor the development, generally at a later age, of conditions such as the chondromalacia of the patella and knee osteoarthritis (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 valgus knee is simple and immediate. It is sufficient, in fact, to observe the knees and verify that:
- The two femurs tend to converge, descending strongly obliquely with respect to the plane of support of the foot;
- The two knees point towards each other;
- The two tibias have a tendency to move further away from each other as they descend towards the feet.
The use of more in-depth diagnostic investigations, starting with physical examination and anamnesis, and ending with an MRI of the knees, allows doctors to understand the causes of valgus knee.
Therapy
If the valgus knee is asymptomatic (in general, milder deformities are asymptomatic), there are no reasonable reasons to resort to therapy, not even the least invasive.
If on the other hand the valgus knee is responsible for a painful symptomatology that strongly affects the quality of life of the patient, the doctors consider it appropriate to resort to some form of treatment.
Treatment options: conservative therapy and surgery
In the presence of a symptomatic valgus knee, the first therapeutic choice of the doctors falls, almost always, on a conservative treatment .
Therefore, if and only if this treatment should fail or be ineffective, surgery is provided.
Conservative treatment
The conservative treatment of the valgus knee mainly involves:
- The use of ad hoc orthopedic and orthopedic shoes ;
- Physiotherapy exercises, aimed at: strengthening the 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.
- 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 valgus knee: the more it is marked, the less are the chances that the aforementioned therapeutic remedies entail a tangible benefit.
Surgery
The surgery, reserved for people with valgus 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 essence, with the femoral osteotomy, the treating orthopedist acts on the femur with the intent of aligning it to the tibia, as in a person not carrying a valgus knee.
If the osteotomy is successful, the obtuse lateral angle, resulting from the particular orientation of the femur with respect to the tibia, disappears (or at least reduces considerably) and the situations of functional overload of a given area of the knee are lost.
Prognosis
Thanks to advances in medicine - both in the field of conservative remedies and in the surgical field, today the valgus knee is a problem that can be overcome with good results and a favorable prognosis.
