Hip dysplasia is classified into different categories depending on severity and clinical course:

1. Mild hip dysplasia:
   • The hip socket is only minimally flattened; joint stability is largely preserved.
2. Moderate hip dysplasia:
   • Significant underdevelopment of the hip socket with early joint instability.
3. Severe hip dysplasia:
   • Severely flattened or malformed hip socket with a high risk of dislocation.
4. Hip dislocation:
   • Complete dislocation of the femoral head from the hip socket.

The causes of hip dysplasia are multifactorial and include:

• Genetic factors:
  • A familial clustering indicates a genetic predisposition.
• Birth position:
  • Children who are born in breech presentation (breech position) have a higher risk of hip dysplasia.
• Sex:
  • Girls are affected significantly more often than boys, which may be due to hormonal influences during pregnancy.
• Firstborns:
  • Firstborn children have an increased risk, presumably due to the greater space restriction in the uterus.
• Limited space in the womb:
  • Multiple pregnancies or a low amniotic fluid volume (oligohydramnios) can restrict the child's freedom of movement and impede optimal development of the hip joints.

Symptoms depend on the age and severity of the malformation:

• Newborns and toddlers:
  • Asymmetric gluteal folds.
  • Limited mobility of the hip joints, especially when spreading the legs.
  • Different leg lengths in advanced dysplasia.
• Adolescents and adults:
  • Hip and groin pain, especially during physical exertion.
  • Movement restrictions, e.g., difficulty climbing stairs or bending over.
  • Instability of the hip joint or a feeling of "slipping out" of the joint.

The diagnosis of hip dysplasia is made through a combination of clinical examination and imaging procedures:

• Clinical examination:
  • The doctor checks the mobility of the hips and looks for typical signs such as asymmetries or clicking sounds.
• Imaging procedures:
  • Ultrasound: Standard examination in newborns for the early detection of hip dysplasia.
  • X-ray: For the assessment of the hip joints in older children and adults.
  • MRI: Detailed visualization of soft tissues and joint structures in cases of unclear findings.

Conservative therapy

In early stages or in newborns, conservative treatment is often sufficient:

• Abduction pants or Pavlik harnesses:
  • Keep the legs in a spread position to promote the optimal development of the hip socket.
• Physiotherapy:
  • Exercises to strengthen the hip muscles and promote joint mobility.
• Pain therapy:
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain in adults.

Surgical therapy

In severe cases or with advanced dysplasia, a surgical procedure may be necessary:

• Pelvic osteotomy:
  • Surgical correction of the hip socket to improve joint stability.
• Hip endoprosthesis:
  • Replacement of the damaged joint with an artificial hip in advanced osteoarthritis.
• Reposition:
  • Surgical reduction of the femoral head into the hip socket in dislocations.

To prevent hip dysplasia in newborns and children, the following measures are recommended:

1. Early detection screenings: Regular ultrasound examinations as part of preventive check-ups.
2. Ergonomic carrying: Use of carriers that keep the child's legs in a spread position.
3. Avoiding overextension: No tight swaddling methods that restrict hip mobility.
4. Education: Parents should be informed about risk factors and symptoms so they can respond early.