Hip dysplasia

What is defined as hip dysplasia?

Hip dysplasia is defined as a condition where the acetabulum does not develop sufficiently. This means that it does not completely cover the femoral head. Insufficient coverage leads to deformity of the joint resulting in unstablea. Instability can occur as a subluxation or even a complete dislocation of the hip.

The term “hip dysplasia” describes a wide range of joint pathology. Its forms can be mild or particularly severe. In severe manifestations, the femoral head is located outside the acetabulum. One of the most internationally accepted classifications of the condition comes from the late Greek Professor of Orthopedics, Hartofillidis. This classification describes three types of dislocation. In the past, the term “congenital hip dislocation” was used to describe the most severe cases of the disorder. However, today the broader and more scientifically accurate term “ Developmental Dysplasia of the Hip” has prevailed.

It can be localized both in one hip and bilaterally, with an increased incidence of:

• in girls.
• in infants with breech projection.
• infants with a family history.

Pathogenetic mechanism of hip dysplasia

Hip dysplasia usually develops during fetal life or in the first weeks after birth. The acetabulum remains shallow or hypoplastic, as a result of which the head of the femur is not adequately covered and then it also acquires dysplasia – deformity

The appearance of dysplasia is based on a combination of factors such as:

• genetic predisposition.
• intrauterine and perinatal conditions.
• looseness of the ligaments surrounding the hip.

These factors disrupt the normal development of the joint and as a result the creation of anatomical abnormalities and a gradual decrease in its normal functionality.

What are the causes of hip dysplasia?

As mentioned above, the pathogenesis of hip dysplasia is multifactorial.

In particular, the causes of hip dysplasia are the following:

• Genetic predisposition: The presence of hereditary factors that affect the smooth development of the hip joint.
• Intrauterine factors: Mechanical constraints during pregnancy (e.g., breech projection) that affect fetal position and motility.
• Perinatal Effects: Factors that favor sagging ligaments, such as the influence of maternal hormones.
• Biomechanical instability: Disruption in the relationship between the femoral head and acetabulum, with abnormal load distribution in the joint, which inhibits the normal development of bone and cartilage structures.

What symptoms does it manifest itself with?

The symptomatology of hip dysplasia varies depending on age. In particular, the clinical picture of age-dependent dysplasia is as follows:

In infants and especially in the first months of life, hip dysplasia is usually asymptomatic and not easily noticed by parents. However, during the clinical examination, characteristic signs may be identified, such as:

• Leg discrepancy
• Asymmetry of skin folds on the thigh or buttocks
• Limited hip abduction, i.e. one hip “opens” less than the other.

In children, hip dysplasia usually manifests itself at the beginning of walking. Therefore, the pathology becomes more evident through movement disorders.

Clinical findings mainly include:

• Lameness.
• Leg unevenness due to a difference in the length of the lower limbs.
• Decreased mobility of the hip, mainly in turning and abduction.

Sometimes toe walking is detected, as a compensatory mechanism for length imbalance and joint instability.

In adolescents and adults, hip dysplasia usually manifests itself when it has not been recognized at a younger age and usually involves milder forms. In this case, the symptoms appear progressively. Pain in the groin or thigh, particularly after exercise or prolonged activity, is the dominant symptom.

It is often accompanied by a feeling of instability, lameness and/or stiffness. Over time, lesions lead to early hip osteoarthritis, causing pain and loss of mobility. In several cases, patients are forced to undergo total hip replacement at ages much younger than the general population.

How is the diagnosis made?

The diagnosis of hip dysplasia is based on the combined evaluation of clinical examination and imaging methods.

Clinical examination is crucial, especially during neonatal and infancy. The Ortolani and Barlow tests are used to assess the stability of the hip by the pediatrician initially, but also by the pediatric orthopedist.

Then, specific imaging tests are performed:

• Ultrasound: It is the method of choice for diagnosing hip dysplasia in newborns and infants up to 6 months of age.
• X-ray of the pelvis and hips: It is indicated after the^6th month of life, providing data on the depth of the acetabulum and the position of the femoral head.

Due to the increased incidence of hip dysplasia in our country in the past, both clinical and ultrasound examination has been applied for many years immediately after birth by pediatricians and pediatric orthopedists. This resulted in the early diagnosis and treatment of cases at a very young age and the reduction of the effects of dysplasia in older ages. .

Hip dysplasia and treatment

The treatment of hip dysplasia varies depending on age and the degree of damage. In children, from the age of 6 months to adolescence, treatment primarily involves surgical techniques. Pericotular osteotomy is a common option, as it corrects the anatomy of the acetabulum to improve the coverage of the femoral head and restore stability.

In infants, it is possible to perform femoral head reduction, either with closed, more often, or with open, more rarely, methods, depending on the degree of dysplasia. Early intervention is crucial, as it reduces the risk of early osteoarthritis and helps maintain hip functionality. In the past, it was common in our country for infants to wear special braces or double diapers, depending on the severity of the problem, to maintain the femoral head in the acetabulum

In adolescents and adults, the therapeutic strategy also focuses on surgical rehabilitation. In mild forms, the method of hip arthroscopy can be applied. Hip arthroscopy is a minimally invasive method to manage any concomitant lesions.

In more severe cases, pericotular osteotomy of the iliac bone improves the geometry of the acetabulum and the coverage of the femoral head, delaying or preventing the need for total arthroplasty. Peritrochanteric osteotomies can also be applied to the femur with the same goal of better coverage of the femoral head. In addition, physiotherapy, weight regulation and avoiding excessive strain improve hip mobility and are supportive measures both before and after surgery.

If you experience hip dysplasia, trust a physician with years of experience and leadership in the field of reconstructive surgery. Orthopaedic Surgeon Anastasios Lilikakis is the Director of the Third Orthopaedic Clinic of the Athens Euroclinic and the President of the Department of Hip & Knee Reconstructive Surgery of EEHOT. Contact us and book your appointment to receive personalized treatment.