Coxa valga

Definition

Dysplastic coxarthrosis, or coxa valga, is an arthrosis of the hip joint caused by congenital underdevelopment of bone structures. Pathology is formed by dysplasia of connective tissue, changes in the shape and size of the acetabulum, and deformation of the femoral head. Symptoms of the disease include “starting” pain and discomfort with any leg movement, progressive mobility limitation, and gait disorders. Diagnosis is carried out according to the radiography data and computed tomography of the joint. Chondroprotectors, analgesics, and surgical correction methods (osteotomy, endoprosthesis, arthrodesis) are prescribed to treat coxarthrosis.

General information

The dysplastic form of coxarthrosis accounts for 7-25% of all hip joint diseases; in 60% of cases, a left-sided lesion is determined; in 5-20% of patients – bilateral. Dysplastic coxarthrosis is mainly found in people 30-40 years old and older since there is a gradual destruction of the articular joint by this age in patients with dysplasia. The disease is more often diagnosed in women. Pathology causes severe restrictions on the function of the lower limb, so it is of great practical importance in modern orthopedics-traumatology.

Causes

The main etiologic factor of the disease is dysplasia of the hip joint, which was not diagnosed in time. In the absence of orthopedic correction, anatomical anomalies progress, so minimal structural changes are transformed over time into dysplastic coxarthrosis. The formation of degenerative-dystrophic processes is promoted by certain risk factors:

• Physical exertion. Regular overloading of the joint in athletes and people who perform physical labor increases instability, contributes to the early onset of pain, and rapidly destroys bone and cartilage structures.
• Damage to the joint. Chronic microdamage and trauma of the hip joint of various etiologies aggravate dysplastic changes and increase cartilage degeneration.
• Aggravated heredity. The presence of dysplasia of the hip joint, coxarthrosis, and arthrosis of other joints in blood relatives increases the likelihood of pathology in the patient.

Risk factors

The anatomical and biomechanical differences between the female and male pelvis result in a higher incidence of dysplastic coxarthrosis in women. This is explained by the acetabulum’s low depth, the pelvis’s wide transverse size, and the skeletal muscles’ weakness, which create preconditions for joint instability. The negative impact of these factors is intensified against the background of excessive weight, so obese patients are at increased risk.

Classification

In practical orthopedics, there is no unified approach to systematizing the disease. According to the change in the position of the femoral head relative to the normal position, there are four types of coxarthrosis (according to Crowe): type I – displacement of less than 10% of the pelvic height, type II – 10-15%, type III – 15-20%, type IV – more than 20%. For proper interpretation of the results of instrumental diagnosis, the classification of arthrosis of the hip joint into three radiologic stages is used:

• Stage I. It is characterized by a slight narrowing of the articular gap, marginal osteophytes (bony overgrowths), and beginning sclerosis of the subchondral plate.
• Stage II. It is manifested by pronounced narrowing of the joint cavity, many osteophytes, subluxation, and mushroom-shaped flattening of the femoral head.
• Stage III. It is defined by typical flexion-adduction contracture of the hip, disappearance of the articular gap, pronounced deformity, and displacement of bony structures.

Symptoms of dysplastic coxarthrosis

The main complaint is pain in the hip joint, which occurs or intensifies at the onset of movement. Painful sensations irradiate to the buttocks or groin area and spread to the anterior and inner surface of the thigh. In rare cases, pain radiates to the knee and lumbar spine. Taking into account the severity of the lesion and individual pain threshold, patients describe their sensations as pulling, stabbing, or aching.

In dysplastic coxarthrosis, pain is accompanied by crepitation and clicking in the joint during walking. Unpleasant sensations and progressive degenerative processes limit the volume of movement, causing patients to begin to limp. Muscle contractures gradually occur, the leg assumes a fixed position, compensatory pelvic misalignment occurs, and the affected lower limb shortens.

Complications

The natural outcome of the disease is articular ankylosis, which makes any movement in the hip joint impossible. It is accompanied by abnormal positioning of the lower limb and the pelvis and spine curvature. With a prolonged course of the disease, dystrophic changes in nerve trunks and fibers develop, aggravating the symptoms. In 60% of people, the ability to work is sharply reduced, and 11.5% develop disability.

A separate group consists of the negative consequences of endoprosthesis and other surgical methods of treating coxarthrosis. Early surgery complications include thromboembolism (9-20.7% of cases), wound suppuration, and purulent-septic processes (1.5-6%). At a later stage, there is a risk of periprosthetic fracture (0.9-2.8% of cases), neuritis (0.6-2.2%), instability of artificial components of the hip joint, and dislocation of the endoprosthesis head (0.4-17.5%).

Diagnosis

Pain and impaired mobility in the hip joint are an indication for consultation with an orthopedic surgeon. Collecting anamnesis and physical examination can identify characteristic symptoms of coxarthrosis, but confirming the diagnosis and establishing the stage of the disease will require advanced instrumental diagnostics. The examination program includes the following areas:

• Radiography. The main method of visualization, which reveals signs of subluxation, assesses the degree of reduction of the articular gap and determines the presence and number of osteophytes.
• CT scan of the hip joint. Clarifying diagnosis is indicated if standard radiographs are not sufficiently informative. Computed tomography is necessary to clearly visualize the bony and cartilaginous components of the hip joint.
• Laboratory tests. To exclude other causes of joint damage, tests for rheumatoid factor and other autoimmune markers are prescribed. The general state of health is assessed by clinical and biochemical blood tests.

Treatment of dysplastic coxarthrosis

Conservative therapy

Pharmacotherapy includes fast-acting symptomatic agents and basic drugs to slow the progression of the disease. The first group includes selective NSAIDs, which reduce pain syndrome and improve the patient’s quality of life. With intense “starting” pain, in the pathogenesis of which vascular disorders play a role, long-acting nitrates are prescribed. Painkillers are also used topically in the form of ointments and gels.

The second group is represented by chondroprotectors—drugs that activate metabolic processes in cartilage tissue, prevent its degeneration, and increase the volume of synovial fluid. They are prescribed in long courses for oral administration. To enhance the effect, chondroprotectors are injected into the joint cavity.

Surgical treatment

Surgical intervention is the only effective method that provides a significant improvement in the condition and eliminates pain syndrome. The choice of surgical tactics is determined by the stage of dysplastic coxarthrosis, the patient’s age and general health indicators, the level of physical activity, and the treatment expectations. The main directions of surgical correction:

• Osteotomy. Minor traumatic surgeries preserve the hip joint, reduce dysplasia, and ensure normal function of the limb. They slow down the development of coxarthrosis and delay the performance of traumatic surgical interventions, so they are most often performed in young patients.
• Total hip replacement. Hip joint replacement is the “gold standard” for treating osteoarthritis and restoring the biomechanics of lower limb movements. A good functional result can be achieved with proper implant selection and competent rehabilitation. After the endoprosthesis is installed, patients return to work and a whole life.
• Arthrodesis. The method involves partial or complete immobilization of the joint with the help of metal fixators. The absence of friction and displacement of bone components completely removes the pain syndrome and prevents further destruction of tissues. However, the operation sharply limits mobility.

All of these treatment options are available in more than 600 hospitals worldwide (https://doctor.global/results/diseases/coxa-valga). For example, Femoral osteotomy can be done in 14 clinics across Turkey for an approximate price of $4.6 K (https://doctor.global/results/asia/turkey/all-cities/all-specializations/procedures/femoral-osteotomy). 

Rehabilitation

After any surgical procedure, the patient needs a long recovery period. This period is based on a properly selected set of physiotherapeutic procedures to strengthen the muscles of the lower limb, gradually restore the volume of movement when fitting a prosthesis, or develop new movement patterns after arthrodesis. Training is supplemented with nutritional therapy, massage, physiotherapy, and swimming. The rehabilitation period is 6 to 12 months.

Prognosis and prevention

Since dysplastic coxarthrosis refers to irreversibly progressive diseases, the long-term outcomes depend on the timeliness and completeness of treatment; a correctly selected complex of surgical correction prolongs the patient’s active life for many years. Still, the joint structures undergo further destruction over time, and the person becomes disabled.

Particular coxarthrosis prophylaxis is prescribed for all patients with diagnosed dysplasia of the hip joint or congenital dislocation of the hip. Annual checkups with an orthopedist to assess the volume of movement and control radiologic diagnostics are indicated. In everyday life, one should avoid heavy physical exertion and traumatic sports, engage in sports to strengthen muscles and maintain weight within the medical norm.