Adolescent Hip Dysplasia

The hip is known as a “ball-and-socket” joint. In a normal hip, the ball at the upper end of the femur (thigh bone) fits deeply into the socket, which is a curved portion of the pelvic bone known as the acetabulum. In an adolescent with hip dysplasia, the hip joint has not developed normally – the acetabulum is either too shallow or does not adequately cover and support the head of the femur ⁽¹⁾. This abnormality can cause a painful hip and the early development of osteoarthritis, a condition in which the articular cartilage in the joint thins and increased contact between the bony surfaces may result in pain and restricted movement ^{(1, 2)}.

Adolescent hip dysplasia usually occurs in young people with a history of developmental dysplasia of the hip. This is a condition that occurs at birth or in early childhood. Although newborn babies and infants are routinely screened for problems with their hip joints, in some cases these remain undetected or are mild enough that they are left untreated. These patients may not show symptoms of hip dysplasia until reaching adolescence. This is where the term adolescent hip dysplasia is most appropriately used.

Adolescent hip dysplasia usually occurs as the result of an initial development abnormality of the hip in early childhood. There are several proposed causes of adolescent hip dysplasia which include ^{(1, 2, 4)}:

• Genetic joint laxity.
• Structural abnormalities – this can include a shallow hip socket (acetabulum), irregular shape to the head of the femur, abnormal rotation of the hip joint or an abnormal angle between the head of the femur (ball) and shaft of the thigh bone.
• Problems in childbirth.

The incidence of hip dysplasia is reported to range from 1.7%-20% in the general population, with most studies finding the incidence between 3%-5 % ⁽²⁾. Females have 2 -4 times increased relative risk of developing hip dysplasia than males. However, males with hip dysplasia tend to have a higher incidence of associated hip joint deformities such as changes in the angle of the femoral head and femoral shaft, or thickening of the femoral neck (known as a cam deformity) ⁽²⁾.

Musculoskeletal physiotherapists and other appropriately qualified healthcare professionals can provide you with a diagnosis by obtaining a detailed history of your symptoms. A series of physical tests might be performed as part of your assessment to rule out other potentially involved structures and gain a greater understanding of your physical abilities to help facilitate an accurate working diagnosis. Your physiotherapist or doctor may perform certain movements that flex and rotate the hip joint to assess for pain, stiffness or catching/clicking within the hip joint.

Your treating clinician will want to know how your condition affects you day-to-day so that treatment can be tailored to your needs and personalised goals can be established. Intermittent reassessment will ascertain if you are making progress towards your goals and will allow appropriate adjustments to your treatment to be made. If adolescent hip dysplasia is suspected, your physiotherapist or doctor may recommend an X-ray or MRI scan to evaluate the degree of changes in the hip joint and confirm the diagnosis ⁽³⁾.

As part of the sessions with your physiotherapist, they will help you to understand your condition and what you need to do to help the recovery from your hip dysplasia. This may include reducing the amount or type of activity, as well as other advice aimed at reducing your pain. It is important that you try and complete the exercises you are provided as regularly as possible to help with your recovery. Rehabilitation exercises are not always a quick fix, but if done consistently over weeks and months then they will, in most cases, make a significant difference.

For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage.

As part of a comprehensive treatment approach, your musculoskeletal physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery. Whilst recovering you might benefit from a further assessment to ensure you are making progress and establish the appropriate progression of treatment. Ongoing support and advice will allow you to self-manage and prevent future reoccurrence.

In cases where there has been significant change in the joint, or conservative treatment has not been able to help manage your pain, a consultation with an orthopaedic surgeon may be required. There are different surgical techniques that could be recommended, including periacetabular osteotomy, to help reposition the ball and socket joint, or hip arthroscopy where damaged or irritable tissue is removed from the lining of the joint.