Hip dysplasia: symptoms, causes and treatment in babies and adults

The hip is a ball-and-socket joint. The Royal Orthopaedic Hospital describes developmental dysplasia of the hip as an umbrella term for bony abnormalities that result in poor containment of the ball (femoral head) within the socket (acetabulum), so the ball is not held tightly in place and there is increased movement within the joint. In very severe cases the ball can come out of the socket (dislocate).

The NHS describes it in babies as a loose joint that can move out of its normal position easily, which can affect one or both hips. It is also called congenital hip dysplasia.

The NHS says DDH is not usually painful, so many parents do not realise their baby has it, and that it is often found during the newborn physical examination. If it is not found early, you might notice the following.

• A clicking or popping sound when they move their hips.

• One leg moving differently from the other during play and nappy changes.

• Legs of different lengths.

• Your baby dragging one leg when they crawl or limping when they start walking.

The NHS says symptoms sometimes do not start until late childhood, puberty or adulthood, especially if the condition is mild and was not found and treated at birth. Typical symptoms are hip pain, pain at the top of the inner thighs (groin pain), and a clicking, snapping or popping feeling when you move the joint.

Steps Charity adds that pain may be felt in the groin or hip or sometimes in the knee or lower back, with limping, stiffness, the hip giving way, or clicking or locking. The Royal Orthopaedic Hospital says patients normally present with pain after prolonged activity that is eased with rest, and some people also have joint hypermobility.

The NHS says it is not clear why DDH happens, but there is a higher chance of a baby having it if they are a girl, someone else in the family has had it, or they moved into a breech position during pregnancy.

The Royal Orthopaedic Hospital says the causes remain much debated and lists known risk factors including being first born, female gender, breech presentation, swaddling as a baby, family history and ligament laxity or hypermobility. It notes that current infant screening does not pick up every case, which is one reason some people are diagnosed later.

If a healthcare professional thinks a baby has DDH they will refer to an orthopaedic surgeon. The NHS says it is diagnosed in babies using an ultrasound scan, which may also be recommended if a baby is more likely to have DDH but has no symptoms. Older children and adults are diagnosed by taking X-rays, because older bones show up more clearly on X-ray than on ultrasound.

Steps Charity says diagnosis is usually made by physical examination, X-ray, MRI or CT. The Royal Orthopaedic Hospital says it is recommended that you are seen by a specialist in young adult hip conditions and that the average time to diagnosis in adults can be around 5 years because dysplasia often masquerades as other issues.

The NHS says DDH can sometimes get better by itself, but most babies need treatment. The most common treatment is a soft fabric Pavlik harness fitted by a healthcare professional, worn for 6 to 12 weeks depending on severity, left on even during nappy changes and bathing. Most babies get used to it after 2 to 3 days, and several scans check that treatment is working.

If the harness does not work or the baby is older, they may need a plastic and foam rigid abduction brace. Rarely, surgery with a temporary cast is needed if DDH is severe or a harness or brace has not worked.

The Royal Orthopaedic Hospital says there are two main options: non-surgical (physiotherapy, lifestyle changes and pain management) and surgical treatment to correct the shape of the hip socket. Steps Charity says the choice depends on age and severity.

The Royal Orthopaedic Hospital says if hip dysplasia is undiagnosed or untreated, the natural progression includes pain, functional limitation and eventually joint degeneration (osteoarthritis), which can start earlier than in others because of uneven wear. Steps Charity says the aim of treatment is to reduce pain, improve movement and delay arthritis, and that many people with hip dysplasia live active lives with appropriate management.

The Royal Orthopaedic Hospital says it is fine to get pregnant if you have hip dysplasia, but the extra weight carried through pregnancy increases the load through the hip joints and may increase pain. If you have hypermobility, the hormone relaxin increases ligament laxity and can cause more pain; physiotherapy, maintaining strong muscles and pelvic corsets can help. It says pelvic osteotomy surgery does not encroach on the birth canal, so you can deliver normally if you wish.

It also notes that hip dysplasia is approximately 12 times more likely when there is a family history, and that if you have a diagnosis it is important that your newborn child has an ultrasound screening.

The NHS says to see a GP if you think you or your child may have DDH, or you or your child have hip pain. Mention any family history. A baby whose legs look different lengths or who clicks on movement should be checked rather than waited on.

Newborn screening and infant hip scans are part of NHS care. Adults are usually referred through a GP to physiotherapy and an orthopaedic or young adult hip service; PAO is specialist surgery. Private hip surgeons offer assessment and surgery; ask about the surgeon’s PAO experience and what rehabilitation is included.