Hip dysplasia is one of the most underdiagnosed conditions I see in practice. Patients often wait years — sometimes decades — before receiving an accurate diagnosis, having been told at various points that their groin pain is a muscle strain, a hip flexor issue, or simply something they need to manage.
This article explains what hip dysplasia is, how it presents in adolescents and adults, how it is diagnosed, and what the treatment options are in New Zealand.
What Is Hip Dysplasia?
Hip dysplasia is a developmental condition in which the hip socket (acetabulum) is too shallow to adequately cover and contain the femoral head (the ball of the hip joint). In a normal hip, the acetabulum provides a deep, stable cup that distributes load evenly across the cartilage surface. In a dysplastic hip, the shallow socket concentrates load on a smaller area — particularly on the rim of the acetabulum — leading to pain, labral tears, and, over time, premature cartilage wear and arthritis.
Hip dysplasia is present from birth in most cases, though it may not cause symptoms until early adulthood or even later. It is significantly more common in women than men, and has a hereditary component — it often runs in families.
Symptoms of Hip Dysplasia in Adults
The most common symptom of adult hip dysplasia is pain in the groin, which is often described as a deep ache that is worse with prolonged walking, standing, or activity. Many patients also notice:
A clicking, catching or clunking sensation in the hip
Pain after sitting for extended periods, particularly when rising from a chair
Difficulty with activities that require hip rotation — such as getting in and out of a car, or crossing the legs
A feeling of instability or the hip “giving way” in some cases
Pain that is worse toward the end of the day or after sport
Symptoms typically begin in the late teens or twenties, though some patients are not diagnosed until their thirties or forties. The condition tends to worsen gradually over time as the labrum and cartilage accumulate damage.
How Is Hip Dysplasia Diagnosed?
Diagnosis begins with a clinical assessment including a detailed history and physical examination. In dysplastic hips, specific provocation tests — including the anterior impingement test and the apprehension test — can reproduce the patient’s symptoms and provide important clinical information.
Imaging is essential for confirming the diagnosis and quantifying the degree of dysplasia:
AP pelvis x-ray — the essential first investigation. Key measurements including the lateral centre-edge angle (LCEA) and acetabular index quantify the degree of undercoverage. An LCEA below 20 degrees is consistent with hip dysplasia (20-25 degrees is borderline dysplasia, which can also be symptomatic).
False-profile x-ray — assesses anterior coverage of the femoral head, which cannot be seen on the standard AP view.
MRI — identifies labral tears, cartilage damage, and the condition of the soft tissue structures, and is important in surgical planning.
If your GP or physiotherapist suspects hip dysplasia, ask for an AP pelvis x-ray as the first step. The x-ray views I recommend are specifically listed in the referral imaging guide on this website. View imaging requirements for referring providers.
Treatment Options for Hip Dysplasia
Treatment depends on the severity of the dysplasia, the degree of cartilage damage, the patient’s age, activity level, and symptom burden.
Non-operative management — including physiotherapy targeted at hip stabilisation, activity modification, and anti-inflammatory medication — can reduce symptoms and slow progression in milder cases, but does not address the underlying structural problem. It is most appropriate for patients who are not suitable for surgery or who have mild symptoms.
Hip arthroscopy may be appropriate for a minority of patients with hip dysplasia and a labral tear, but only in carefully selected cases where the degree of dysplasia is very mild and the labrum can be repaired without placing it under excessive tension.
Periacetabular osteotomy (PAO) is the gold-standard surgical treatment for symptomatic hip dysplasia in younger adults with preserved cartilage. PAO involves carefully cutting and repositioning the acetabulum to improve coverage of the femoral head, restoring a more normal load distribution and protecting the cartilage and labrum from further damage. Learn more about PAO surgery.
Total hip replacement is the appropriate treatment for patients with end-stage arthritis secondary to hip dysplasia, but is generally deferred as long as possible in younger patients.
Why Early Diagnosis Matters
Hip dysplasia is a progressive condition. The longer it goes undiagnosed and untreated, the greater the cumulative damage to the labrum and cartilage — and the narrower the window for joint-preserving surgery. PAO produces the best outcomes in patients with well-preserved cartilage. Once significant arthritis develops, the options change fundamentally.
If you are a young or middle-aged adult with unexplained groin pain, clicking in the hip, or a family history of hip problems, it is worth asking your GP or physiotherapist about hip dysplasia specifically.
Getting a Referral in Auckland
Dr. Matthew Boyle is a fellowship-trained orthopaedic surgeon in Auckland with a specialist interest in hip conditions including hip dysplasia and PAO surgery, and sees patients from across New Zealand for this subspecialty. His clinic is located at AUT Millennium, 17 Antares Place, Rosedale, Auckland. Ask your GP or physiotherapist for a referral or contact the clinic directly. GPs and physiotherapists can refer via HealthLink EDI: drmboyle.
This article is for general educational purposes only and does not constitute medical advice. Please consult your doctor or seek a specialist referral for personal medical advice.
