Developmental Dysplasia of the Hip

DDH can be classified into different types depending on the severity:

• Hip instability: The hip joint is looser than normal and may slip in and out of place.
• Hip subluxation: The head of the thigh bone (femur) is partly displaced from its socket.
• Hip dislocation: The head of the thigh bone is completely out of the socket.

Depending on the age of the child, one or more of the following symptoms are noted:

• Newborns and infants may have unequal leg lengths, folds on the thighs or buttocks that do not match, and abnormal hip movement.
• Asymmetry of the thighs or gluteal folds and abnormal movements of the hip joint.
• Children who have started walking may have pain on the affected side, limp while walking, or show reduced movement of the hip joint.

DDH is caused by the misalignment of the head of the femur into the hip socket; this may occur when the femur is abnormally shaped or if the hip socket is too shallow. Moreover, the following risk factors for DDH have been identified:

• Female sex.
• First-born babies, especially first-born girls, are at higher risk.
• A family history of DDH increases the chances of it occurring.
• Breech position (baby’s feet coming out first instead of the head).
• Other conditions affecting the brain and nerves, such as cerebral palsy.

Doctors use a combination of the following techniques to diagnose DDH:

• Physical examination of the newborn using special tests such as the Barlow test (to check if the hip can slip out of the socket) and the Ortolani test (to check if the hip can be put back in place).
• Observation of walking pattern in older children and examination of the spine and knees.
• Ultrasonography is the preferred test in babies younger than 6 months.
• Pelvic radiography (X-ray) is more useful in children older than 6 months.
   

Based on the age of the patient and severity of the condition, one or more of the following treatment approaches are recommended:

• Non-surgical treatments: This is the first choice for young babies and in early stages:
  • A Pavlik harness (a soft brace) may be used in babies under 6 months to keep the hips in the correct position.
  • A hip spica cast (a plaster cast around the hips, pelvis, and sometimes knees) may be used to hold the hip in place.
• Surgical treatment: Surgery may be needed if the hip cannot be reduced (put back in place) or in older children. Procedures include:
  • Open reduction involves surgically placing the hip back in the socket and then applying a cast.
  • Osteotomy involves reshaping or repositioning the bones of the pelvis, hips, or both, followed by fixation using plates and screws.
  • Hip replacement maybe considered in adults who have had untreated dislocation for many years.

Parents are advised to visit their doctor if they notice uneven leg lengths, asymmetry in thigh or buttock folds, limping, or restricted movement in their child’s hips. Early detection is very important because treatment works best when started early.

There is no guaranteed way to prevent DDH, but a few measures may help reduce the risk:

• Avoid tightly swaddling a baby’s legs in a straight position; instead, allow room for free hip movement.
• Regular check-ups after birth help ensure early detection and treatment.

If DDH is suspected, parents should consult a paediatric orthopaedic specialist. In some cases, a physiotherapist may also be involved in rehabilitation after treatment.