Developmental Dysplasia of the Hip in Adults

What is developmental dysplasia of the hip in adults?

Developmental dysplasia of the hip (DDH) is a condition in which the hip socket, called the acetabulum, is too shallow or angled in a way that does not fully cover the ball at the top of the thigh bone (the femoral head). The word dysplasia simply means abnormal development. Because the socket does not hold the ball securely, the joint is less stable than it should be, and the smooth cartilage that lines the joint is placed under uneven, concentrated pressure.

Many people think of hip dysplasia as a condition of babies, and it is usually looked for in newborn checks. However, milder forms are often missed in childhood because the hip is not dislocated and the child walks normally. Hip dysplasia in adults refers to this same shallow-socket anatomy that either was never detected, or was treated in childhood but did not fully correct. It is one of the more common structural causes of hip pain in teenagers and adults under the age of about 50, and it is a recognized cause of early osteoarthritis of the hip (wear of the joint cartilage).

Adult hip dysplasia is diagnosed more often in women than in men, and symptoms frequently first appear in the late teens, twenties or thirties, often after a period of increased activity, a pregnancy or a minor injury. It can affect one hip or both. In hospital settings this condition is typically managed by orthopedic surgeons with an interest in hip preservation; at Acibadem, for example, it falls under the Orthopedics & Joint Center.

Symptoms of hip dysplasia in adults

Adult hip dysplasia symptoms often start gradually and may be vague at first, which is one reason the diagnosis is sometimes delayed. Common symptoms include:

• Pain in the groin or the front of the hip, often described as deep or aching
• Pain on the outer side of the hip or in the buttock
• Pain that worsens with walking, running, prolonged standing or sitting for long periods
• A feeling that the hip is unstable, "giving way" or slipping
• Clicking, catching or locking sensations in the hip
• Stiffness or reduced range of motion, especially when bringing the knee toward the chest or rotating the leg
• A limp, particularly after activity or at the end of the day
• Tiredness or a sense of muscle fatigue around the hip and thigh

How symptoms feel often depends on the stage of the condition. In earlier stages, when the cartilage is still largely intact, discomfort may only occur during or after sport or heavy activity, and rest usually relieves it. Some people describe difficulty sitting cross-legged or a pinching feeling when the hip is flexed.

As the shallow socket continues to overload the rim of the joint, the labrum (a ring of cartilage that seals the edge of the socket) can tear or fray. A labral tear frequently adds sharp, catching pain and mechanical clicking to the background ache.

In later stages, when osteoarthritis has developed, pain tends to become more constant, may disturb sleep, and stiffness becomes more prominent. Walking distance may shorten, and simple tasks such as putting on shoes or getting out of a car may become difficult. Not everyone with hip dysplasia follows this path, and the speed of change varies widely from person to person.

Causes and risk factors

Hip dysplasia is a developmental condition, which means it results from the way the hip joint formed during growth rather than from something a person did. The exact cause is not fully understood, but it is generally considered to be a combination of inherited factors and mechanical influences before and shortly after birth. The ball and socket normally shape each other as the child grows; if the ball is not held deeply in the socket during this period, the socket may not deepen properly.

Recognized risk factors include:

• Family history: having a parent or sibling with hip dysplasia increases the chance of being affected, suggesting a genetic component.
• Female sex: girls and women are diagnosed more often than boys and men.
• Firstborn child: a tighter uterus in a first pregnancy may limit the baby’s hip movement.
• Breech position: babies who were positioned bottom-first in the womb, especially late in pregnancy, have a higher risk.
• Low amniotic fluid (oligohydramnios): less room to move in the womb may affect hip development.
• Swaddling with the legs straight and together in infancy, which holds the hips in a position that does not encourage the socket to deepen.
• Generalized joint laxity or connective-tissue conditions that make ligaments looser than usual.
• Previous childhood hip treatment that did not fully correct the socket shape.

In adults, factors that do not cause dysplasia but may bring symptoms to the surface include high-impact sport, weight gain, pregnancy, and occupations that involve prolonged standing or heavy lifting. These increase the load on a joint that is already mechanically disadvantaged.

Diagnosis

Diagnosing hip dysplasia in adults begins with a careful history and physical examination. Your doctor will usually ask about the location and pattern of your pain, what makes it better or worse, any childhood hip problems, and whether relatives have had hip disease or early hip replacements. On examination, the doctor may check your walking pattern, the range of motion of the hip, and perform specific movements, such as bending and rotating the hip inward, to see whether they reproduce your pain. Signs of general joint looseness may also be assessed.

Imaging is essential to confirm the diagnosis, because the symptoms overlap with several other hip conditions:

• Plain X-rays of the pelvis and hip, taken standing where possible, are the first and most important test. Radiologists and surgeons measure how well the socket covers the femoral head. The most commonly used measurement is the lateral center-edge angle, which describes how far the roof of the socket extends over the ball. A reduced angle indicates a shallow socket. Other measurements assess the tilt of the socket and whether the ball has begun to move outward. X-rays also show whether the joint space has narrowed, which is a sign of arthritis.
• Magnetic resonance imaging (MRI) shows soft tissues that X-rays cannot, including the labrum and the articular cartilage. It is often used to look for labral tears and early cartilage damage. Sometimes a contrast dye is injected into the joint first (an MR arthrogram) to make these structures easier to see.
• Computed tomography (CT) creates detailed three-dimensional images of the bone. It is often used in surgical planning to understand the exact shape and orientation of the socket and femoral head.
• Diagnostic injection of local anesthetic into the hip joint may be used in some cases. If the pain clearly improves for a period after the injection, this supports the hip joint itself, rather than the spine or surrounding muscles, as the source of pain.

Hip dysplasia is usually described as mild, moderate or severe based on these measurements, and it may be classified as "borderline" when the socket is only slightly shallow. Because a shallow socket can exist alongside other problems, such as excess bone on the femoral neck (femoroacetabular impingement), the specialist will try to build a complete picture of the joint before discussing treatment.

Treatment options for hip dysplasia in adults

Hip dysplasia in adults treatment depends on several factors: how shallow the socket is, how much cartilage damage has already occurred, your age, your activity level and how much the symptoms limit your life. The main goals are to reduce pain, protect the remaining cartilage and, where possible, delay or prevent the need for a hip replacement. Treatment generally falls into non-surgical and surgical approaches.

Non-surgical management

For mild dysplasia, early symptoms or people who are not candidates for surgery, doctors often start with conservative measures:

• Activity modification: reducing high-impact activities such as running or jumping and favoring low-impact exercise such as swimming or cycling may lessen pain.
• Physical therapy: exercises to strengthen the gluteal and core muscles can improve how the hip is controlled and may reduce feelings of instability. Therapy cannot change the shape of the bone, but it may help many people manage symptoms.
• Weight management: maintaining a healthy weight reduces the forces passing through the joint.
• Medication: over-the-counter pain relievers and anti-inflammatory medicines may be used for flare-ups, as advised by a doctor.
• Injections: a corticosteroid injection into the joint may give temporary relief in some cases, though it does not address the underlying cause and is generally not repeated frequently.

Observation with periodic X-rays may be recommended when dysplasia is mild and symptoms are minimal, so that any progression can be identified early.

Hip dysplasia surgery

When pain persists despite conservative care, or when imaging suggests that the joint is being damaged, surgery may be discussed. The choice of operation depends largely on whether the cartilage is still healthy.

Periacetabular osteotomy (PAO) is the main joint-preserving operation for adults with symptomatic dysplasia and little or no arthritis. An osteotomy is a controlled cut in a bone. In a periacetabular osteotomy, the surgeon makes a series of cuts around the socket to free it from the rest of the pelvis, then rotates the socket into a position that covers the femoral head more completely, and fixes it in place with screws. This redistributes load across a larger area of cartilage and improves stability. The pelvis heals in the new position over several months. PAO is a major operation, usually reserved for skeletally mature adolescents and adults, typically younger than about 40 to 45, whose cartilage is still in reasonably good condition. Recovery involves a period of protected weight-bearing with crutches followed by a structured rehabilitation program, and full recovery commonly takes many months.

Hip arthroscopy is a keyhole procedure in which a small camera and instruments are passed into the joint. It can be used to repair a torn labrum or trim excess bone. In dysplasia, arthroscopy alone is used cautiously, because treating the labrum without correcting the shallow socket does not address the underlying problem and may, in some cases, increase instability. It is sometimes combined with a periacetabular osteotomy.

Femoral osteotomy reshapes or reorients the upper thigh bone and may be added when the shape of the femur also contributes to the poor fit of the joint.

Total hip replacement (arthroplasty) becomes the main option once significant osteoarthritis has developed and the cartilage can no longer be preserved. The damaged ball and socket are replaced with artificial components. Hip replacement in a dysplastic hip can be technically more demanding because the bone anatomy is altered, and the surgeon may need specialized implants or bone grafting. It is a well-established operation that often relieves pain substantially.

Rehabilitation

Whatever the treatment, rehabilitation is a core part of recovery. After surgery, physical therapy focuses first on protecting the healing bone or implant, then on restoring range of motion, and finally on rebuilding strength and normal walking patterns. Following the therapist’s guidance on weight-bearing limits and activity progression is important for the result.

Living with developmental dysplasia of the hip in adults and outlook

The outlook for adults with hip dysplasia varies considerably. Some people with mild dysplasia have few symptoms for many years and manage well with activity adjustments and exercise. Others, particularly those with more severe socket shallowness, tend to develop arthritis at a younger age than the general population. Doctors cannot predict with certainty how any individual hip will change over time, which is why regular follow-up is often recommended.

When a periacetabular osteotomy is performed before significant arthritis has set in, many patients experience meaningful pain relief and improved function, and the operation is intended to delay or avoid hip replacement. However, results depend on the condition of the cartilage at the time of surgery, the accuracy of the correction and individual factors, and some people may still require a hip replacement later in life. Your surgeon may discuss the realistic expectations for your particular situation.

Day-to-day, many people find it helpful to stay active within comfortable limits, keep supporting muscles strong, avoid prolonged periods of sitting in deep chairs or with crossed legs if these provoke symptoms, and use supportive footwear. Pregnancy can increase hip discomfort because of hormonal joint loosening and weight changes; discussing this with your doctor in advance may help with planning. Living with a long-term hip problem can also be emotionally tiring, and it is reasonable to seek support if pain begins to affect mood, sleep or work.

Frequently asked questions

Can hip dysplasia in adults go undiagnosed for years?

Yes. Mild dysplasia often causes no symptoms in childhood because the hip is not dislocated and the child walks normally. Symptoms commonly appear in the teens or adulthood when the joint has been loaded for years, and the condition is sometimes only recognized when X-rays are taken for hip pain that was initially blamed on a muscle strain or another cause.

What are the first adult hip dysplasia symptoms to look out for?

The earliest sign is often a deep, aching pain in the groin or front of the hip that comes on during or after activity and eases with rest. Some people notice clicking, a feeling of the hip giving way, or difficulty sitting for long periods. These symptoms are not specific to dysplasia and can have other causes, so imaging is needed to confirm the diagnosis.

Is periacetabular osteotomy the only hip dysplasia surgery?

No. Periacetabular osteotomy is the main joint-preserving operation for adults with dysplasia and healthy cartilage, but other options exist. Hip arthroscopy may be used to treat labral tears, sometimes in combination with PAO. When arthritis is advanced, total hip replacement is usually recommended instead. The right choice depends on your age, the degree of dysplasia and the state of the cartilage.

How long does recovery from a periacetabular osteotomy take?

Recovery is gradual. Most people use crutches with limited weight-bearing for several weeks while the pelvis heals, then progress through physical therapy to rebuild strength and normal walking. Returning to desk work may be possible within a few weeks to months, while a return to more demanding activity or sport often takes many months. Your surgical team can give a timeline based on your circumstances.

Can exercise or physical therapy cure hip dysplasia in adults?

Physical therapy cannot change the shape of the bony socket, so it does not cure dysplasia. It can, however, strengthen the muscles that stabilize the hip, improve movement patterns and reduce pain in many people, particularly those with mild dysplasia. It is also a central part of recovery after any hip dysplasia surgery.

Does hip dysplasia in adults always lead to hip replacement?

Not always. Some people with mild dysplasia never need surgery, and joint-preserving operations such as periacetabular osteotomy aim to delay or avoid replacement. That said, moderate to severe dysplasia is a recognized cause of early osteoarthritis, and some people will eventually require a hip replacement. Regular monitoring helps identify changes early.

Is hip dysplasia in adults hereditary?

There appears to be a genetic component, as the condition is more common in people with an affected parent or sibling. Genetics is not the whole story, since factors such as breech birth and position in the womb also play a role. If you have hip dysplasia, it is reasonable to mention this to your child’s doctor so that their hips can be checked.

When to see a doctor

You may wish to consult a doctor if you have hip or groin pain that has lasted more than a few weeks, that limits your activity, or that is accompanied by clicking, catching or a sense of instability, especially if you have a family history of hip dysplasia or were treated for a hip problem as a baby. Early evaluation allows joint-preserving options to be considered while they are still possible.

Seek urgent medical attention if you experience any of the following:

• Sudden, severe hip pain after a fall or injury, or an inability to bear weight on the leg
• A hip that appears deformed, shortened or turned outward
• Fever, chills or feeling generally unwell together with a hot, swollen or intensely painful hip, which may indicate infection
• Numbness, tingling or weakness in the leg or foot
• After hip surgery: increasing redness, warmth or discharge from the wound, calf pain or swelling, chest pain or shortness of breath
• Pain that is rapidly worsening or that wakes you from sleep every night

These signs do not necessarily mean something serious is happening, but they should be assessed promptly by a healthcare professional.