bone health

Coxa Valga

Generality

The coxa valga is the deformity of the hip in which the angle existing between the head-neck complex of the femur and the body of the femur measures at least 140 degrees, that is at least 5 degrees more than that which represents normality.

Image taken from en.wikipedia.org

An example of valgus, coxa valga can be the result of some neuromuscular diseases (eg: cerebral palsy), some skeletal dysplasias (eg: mucopolysaccharidosis) or hip trauma at a young age, such as to alter the normal growth process of the femur .

In coxa valga carriers, the presence of symptoms depends on the degree of the deformity: if the deformity is slight, the coxa valga is asymptomatic; on the contrary, if the deformity is severe, the coxa valga is responsible for various disorders (eg: lameness, pain in the hip, joint stiffness, etc.) and can give rise to serious complications (eg, osteonecrosis of the femoral head).

The diagnosis of coxa valga is generally based on: physical examination, medical history and a radiological examination related to the hip.

In the presence of coxa valga, the use of a therapy and the type of therapy adopted depend on the presence or absence of symptoms.

Short reminder of the valgism

Valgism is the orthopedic term that indicates the deformities of the limbs in which, due to an abnormal relationship between two adjacent bones or between two contiguous portions of the same bone, the most distal of these two presents a lateral orientation, ie tends to move away into atypical way from the sagittal plane.

The presence of valgus can have different consequences on the articulation in which the deviated skeletal element participates, consequences that can be of an anatomical nature and, in the most serious cases, also of a functional nature. Furthermore, some painful symptoms may also depend on valgism.

Table . Meanings of proximal-distal, sagittal and medial-lateral plane
Proximal Distal
It means "closer to the center of the body" or "closer to the point of origin". Examples:
  • The femur is proximal to the tibia, which is proximal to the bones of the foot;
  • In the femur, the extremity bordering the trunk is the proximal end.

It means "further away from the center of the body" or "further away from the point of origin".

Examples:

  • The tibia is distal to the femur;

  • In the femur, the extremity bordering on the knee is the distal end.
Sagittal plane
Antero-posterior division of the human body, from which two equal and symmetrical halves are derived.
Medial Lateral
It means "near" or "closer" to the sagittal plane.

Example:

  • The first toe (big toe) is medial to the other toes.

It means "far" or "farther" from the sagittal plane.

Example:

  • The second, third, fourth and fifth toes are all lateral to the big toe.

What is coxa valga?

Coxa valga is the name of the hip deformity in which the characteristic angle existing between the femoral head-neck complex and the femur body measures at least 140 degrees, ie minimum 5 degrees more than the maximum limit that defines the normal range for the corner in question.

The angle between the femoral head-neck complex and the femur body is normal when its gradation is between 120 and 135 degrees .

Why is it an example of valgus?

The coxa valga is an example of valgism, because, due to the greater gradation of the angle existing between the femoral head-neck complex and the femur body, the latter has the tendency to assume a more lateral orientation than the normal, in order to compensate for the greater width of the aforementioned angle.

Coxa valga can be mono- or bi-lateral

Coxa valga may be a problem limited to one hip only ( coxa valga unilateral ) or both ( coxa valga bilateral ).

Normally, the cause, or the cause, affects the involvement of one or both joints.

Is it the opposite of coxa vara?

Coxa valga is the deformity of the hip opposite to coxa vara . On the basis of medical definitions, in fact, the coxa vara is the anomaly of the hip in which the angle existing between the proximal end of the femur and the body of the femur measures less than 120 degrees, ie less than the minimum limit that establishes the normal range for the angle in question.

The coxa vara is an example of varus, the condition contrary to valgism.

Causes

Possible causes of coxa valga include:

  • Neuromuscular diseases, such as cerebral palsy, poliomyelitis and spinal dysraphism ;
  • Some forms of skeletal dysplasia, including mucopolysaccharidosis and Turner syndrome ;
  • Hip trauma at a young age, such as to interfere with the correct growth process of the femur.

While the aforementioned neuromuscular diseases and the aforementioned forms of skeletal dysplasia are more often responsible for bilateral coxa valga, hip injuries that interfere with the normal growth process of the femur are more frequently associated with unilateral coxa valga.

Symptoms and complications

In people with coxa valga, the presence of symptoms and signs is strictly dependent on the severity of the joint deformity. In fact, when it is mild, the coxa valga tends to be asymptomatic; on the contrary, when it is severe, it is generally associated with various symptoms and signs, including:

  • Hip pain (if the deformity is unilateral) or both hips (if the deformity is bilateral);
  • Loss of joint mobility on the part of the hips;
  • Joint stiffness felt on one or both sides, depending on whether the deformity is mono- or bi-lateral;
  • Lameness;
  • Spasticity of the adductor muscles of the hip, due to their abnormal overdevelopment (especially if compared with the abductor and extensor muscles of the hip);
  • Shortening of one or both lower limbs, depending on whether the deformity is, unilateral or bilateral, respectively (clearly, in the unilateral coxa valga, the lower limb that undergoes shortening is the one that carries the deformity);
  • Knee launch . The varus knee is the deformity of the lower limbs which mirrors a misalignment of the femur and tibia, such that the two knees point outwards, bones facing away from each other.

Complications

The most severe cases of coxa valga can degenerate into episodes of osteonecrosis of the femoral head, in events of dislocation or subluxation of the femoral head and in very painful decubitus ulcers (or bedsores ).

Curiosity: what is osteonecrosis?

Osteonecrosis is the death of bone tissue due to a missed or insufficient blood supply.

Also known as avascular necrosis, bone necrosis or bone infarction, osteonecrosis has the consequence of the appearance of tiny fractures in the affected bone tissue and, especially in more severe cases, the so-called bone collapse phenomenon.

Diagnosis

As a rule, for an accurate and safe diagnosis of coxa valga, a thorough physical examination, a thorough medical history, and an instrumental examination such as a hip radiograph are indispensable.

What is the physical examination for?

The physical examination consists in the medical observation of the symptoms and signs, revealed by the patient.

Very often, it includes the execution, by the patient and on doctor's advice, of specific maneuvers or gestures, which serve to bring to light certain characteristic signs of the present pathological condition.

What is the medical history used for?

The anamnesis (or clinical history) is the critical study of the symptoms and of all the facts of medical interest, reported by the patient or by the relatives of the latter.

In the case of coxa valga, the anamnesis is fundamental to trace the causes of deformity; it is in fact through the investigations of clinical history that the doctor becomes aware of any traumas passed to the hip, the presence of neuromuscular diseases, etc.

What may be in-depth examinations?

If the radiograph of the hip is not exhaustive and does not allow a definitive diagnosis, the doctors could prescribe diagnostic examinations for more in-depth images, such as nuclear magnetic resonance or the CAT scan of the pelvis .

What is the appearance of the femur in radiological images?

Radiological images of an individual's hip with coxa valga show the femoral head tending to align with the body of the femur. This anomaly is the normal consequence of the greater amplitude of the angle existing between the two observed femoral portions.

Therapy

For asymptomatic cases of coxa valga, no treatment is needed.

For cases of coxa valga slightly symptomatic, the treatment canonically foreseen is conservative and consists of physiotherapy .

Finally, for severely symptomatic cases of coxa valga, the only currently effective therapy is a surgical procedure known as the femoral osteotomy with varitating effect (or varus femoral osteotomy ).

Femoral Osteotomy with Variation Effect

Quite delicate intervention, the femoral osteotomy with varant effect involves the remodeling of the proximal femoral portion, in order to reduce the present valgism (NB: deriving from varus, the opposite condition to the valgism, the term "varantizing effect" refers to its own aforementioned purpose).

In the presence of a coxa valga severely symptomatic, the risk / benefit ratio of a delicate operation such as the femoral osteotomy with variator effect leans in favor of the latter. In other words, when coxa valga is severe and very debilitating, it is better to operate and take the risks of surgical therapy, which does not leave room for the possible complications of the present deformity.

Prognosis

In the case of coxa valga, the prognosis depends on several factors, including:

  • The degree of severity of the deformation. The more severe the deformation, the more difficult the treatment;
  • The timeliness of the treatment. Failure to treat coxa valga increases the probability that serious complications arise from the latter;
  • Monolateralism or bilaterality of the condition. Bilateral coxa valga is generally more severe than unilateral coxa valga;
  • The triggering cause. Some causes of coxa valga alter normal hip anatomy more profoundly than others.

In ideal conditions (treatable deformity, timely treatment etc.), surgical operations aimed at correcting the most serious cases of coxa valga can guarantee good results.