Przejdź do treściAdult hip dysplasia means that the acetabulum provides insufficient coverage of the femoral head. It can cause groin pain, a sense of overload or instability and, over time, contribute to labral and cartilage damage. The diagnosis should not be made from a single X-ray angle alone: symptoms, clinical examination and appropriately performed imaging all matter.
Polish version: Dysplazja biodra u dorosłych — objawy, diagnostyka i leczenie
What is adult hip dysplasia?
In a normally shaped hip, the acetabulum covers enough of the femoral head to distribute load across an adequate joint surface. In dysplasia, that coverage is reduced. This can increase stress at the acetabular rim, labrum and articular cartilage and may contribute to hip microinstability.
Not every radiographic feature of undercoverage represents a symptomatic condition that requires treatment. Similar morphology can also be found in people without hip pain. Imaging therefore needs to be interpreted together with symptoms and the clinical examination.
Which symptoms can suggest hip dysplasia?
- groin pain, especially with prolonged walking, running or deep hip flexion,
- a sense of fatigue or overload around the hip after activity,
- pain on the lateral side of the hip or, less commonly, in the buttock,
- a feeling of instability or that the hip is giving way,
- catching, clicking or sharp pain during twisting movements, particularly when labral damage is also present.
These symptoms are not specific to dysplasia. Similar pain can arise from femoroacetabular impingement, the labrum, tendons, the lumbar spine or other soft tissues around the hip. The source of pain therefore needs to be established rather than assumed from one imaging measurement.
How does an orthopaedic surgeon diagnose hip dysplasia?
Assessment starts with the history and clinical examination. The location of pain, range of motion, signs of instability or impingement, muscle strength and other potential sources of symptoms are considered. Properly performed radiographs of the pelvis and hip are the basic imaging tests.
What does the Wiberg angle mean?
One commonly used measurement is the lateral centre-edge angle, also known as the Wiberg angle or LCEA. An international 2026 consensus considered an LCEA below 20° typical of dysplasia, while values of 20–25° may raise suspicion of possible instability.
This is not a rule in which “below 25° means surgery”. Pelvic positioning and radiographic technique can affect the measurement, and acetabular shape is three-dimensional. Other measurements, acetabular version, proximal femoral morphology and the condition of the cartilage may therefore also need to be considered.
When are MRI or CT useful?
MRI may be needed to assess the labrum, cartilage and other soft tissues, particularly when surgery is being considered or when symptoms are not adequately explained by radiographs. CT can be useful for a more detailed three-dimensional assessment of acetabular and femoral anatomy and orientation.
Ultrasound is not the primary test for assessing femoral-head coverage in an adult. It can, however, be useful when tendons or other soft tissues around the hip need evaluation or when a diagnostic injection is to be performed accurately.
Does hip dysplasia always require surgery?
No. Management depends on the severity of symptoms, the degree of undercoverage, joint stability, the biological condition of the joint and the presence of osteoarthritis. For some patients, non-operative treatment is a reasonable first step.
- modifying activities that clearly provoke pain without eliminating movement altogether,
- exercises aimed at improving hip and trunk strength and control,
- gradual adjustment of sporting and occupational loads,
- pain-relieving or anti-inflammatory medication when appropriate and when there are no contraindications.
In a review that included several non-arthritic causes of hip-related pain, including dysplasia, roughly half of patients achieved a satisfactory response to non-operative treatment. That figure should not be interpreted as the response rate for every form of dysplasia, because the included studies combined several different diagnoses.
What is periacetabular osteotomy?
In appropriately selected patients with symptomatic dysplasia and preserved cartilage, periacetabular osteotomy (PAO) may be considered. Controlled bone cuts allow the acetabulum to be mobilised and reoriented so that it provides better coverage of the femoral head. The aim is to improve joint mechanics while preserving the native hip.
Long-term reviews report improvement in patient-reported outcomes after PAO, but most available evidence comes from observational studies of carefully selected patients. The presence of dysplasia on an X-ray is therefore not, by itself, an indication for osteotomy.
What about hip arthroscopy?
Hip arthroscopy can address labral damage or coexisting impingement, but it does not increase bony coverage of the femoral head. In true instability caused by dysplasia, repairing the labrum alone does not correct the underlying biomechanical problem. Borderline cases in particular require assessment of the hip’s overall geometry rather than one isolated measurement.
When is joint replacement considered instead of joint-preserving surgery?
If dysplasia is accompanied by advanced osteoarthritis and substantial cartilage damage, the potential benefit of a joint-preserving procedure may be limited. Depending on symptoms and function, total hip replacement may then be considered. More about this pathway: Hip Replacement.
When does hip pain need more urgent assessment?
- after an injury, you cannot bear weight or there is an obvious deformity,
- the joint is very painful and hot, particularly with fever or systemic illness,
- pain is rapidly increasing at rest or at night, especially with unexplained general symptoms,
- there is sudden weakness, sensory loss or another new neurological symptom in the limb.
Key point: treat the symptomatic hip, not an X-ray angle
Hip dysplasia is a structural problem, but treatment decisions come from the combination of symptoms, examination, properly obtained radiographs and, when needed, MRI or CT. A single angle can support the diagnosis but cannot replace a complete assessment. Non-operative care is sufficient for some people, while selected patients with persistent symptoms and limited degenerative change may be candidates for surgery that preserves the native joint.
References
- Leopold VJ, Rakhra K, Spiker AM, et al. Which Imaging Modalities, Parameters, and Diagnostic Thresholds Best Define Hip Instability? Consensus Statements From a Scoping Review and an International Multidisciplinary Delphi Study. Clinical Orthopaedics and Related Research. 2026;484(5):899–915. DOI: 10.1097/CORR.0000000000003905.
- MacLeod JS, Zhu JR, Lee MS, et al. Periacetabular Osteotomy Leads to Improved Long-term Patient-reported Outcomes: A Systematic Review. Orthopedics. 2025;48(3):e113–e123. DOI: 10.3928/01477447-20250409-03.
- O’Brien MJM, Semciw AI, Mechlenburg I, et al. Pain, function and quality of life are impaired in adults undergoing periacetabular osteotomy for hip dysplasia: a systematic review and meta-analysis. Hip International. 2024;34(1):96–114. DOI: 10.1177/11207000231179610.
- Probst DT, Sookochoff MF, Harris-Hayes M, et al. What is the Rate of Response to Nonoperative Treatment for Hip-Related Pain? A Systematic Review With Meta-analysis. Journal of Orthopaedic & Sports Physical Therapy. 2023;53(5):286–306. DOI: 10.2519/jospt.2023.11666.
Content prepared by: Tomasz Poboży - orthopaedic surgeon.