Hip Dysplasia
Adult hip dysplasia is a shallow hip socket that does not fully cover the ball — it overloads the rim and can cause pain, instability and, over time, early arthritis. Physiotherapy can’t change the shape of the joint, but it is central to managing symptoms and protecting the hip, and we’ll guide you honestly on when a surgical opinion is right.
Hip dysplasia: a socket that is too shallow
In hip dysplasia the acetabulum (socket) is too shallow and does not fully cover the ball of the hip. That leaves the joint under-supported, so the rim and labrum take too much load — which can cause pain, a feeling of instability, and, over years, early osteoarthritis. It is a structural condition: often present from early life and only causing trouble in the teens, twenties or thirties.
What it feels like
Usually groin or front-of-hip pain that builds with standing, walking and activity, sometimes with a limp or a sense the hip will give way. Pain on the outer hip and fatigue in the buttock muscles are common, as those muscles work overtime to stabilise an under-covered joint.
Who gets it
It is noticeably more common in women (around two to four times), and linked to breech birth, being a first child and a family history. It matters because dysplasia is a leading cause of hip arthritis in younger adults — a large share of hip replacements under 50 trace back to it (Gala et al., 2016).
Hip dysplasia on X-ray
A standing pelvic X-ray of an adult with dysplasia. The sockets are shallow and steep, leaving the femoral heads under-covered — so the rim and labrum carry more load than they are built for.
X-ray: Ping Zhen, et al., CC BY 4.0, via Wikimedia Commons.
Measured on an X-ray
Dysplasia is confirmed on X-rays (a standing pelvis view and a “false-profile” view), where we measure how well the socket covers the head. The key measure is the lateral centre-edge angle (LCEA): broadly, 25° or more is normal cover, around 20–25° is borderline, and under 20° indicates true dysplasia (Martz et al., 2024). Other angles (Tönnis, the false-profile view for front cover) add detail, and an MRI shows the labrum and cartilage.
How dysplasia is measured
Dysplasia is graded from the X-ray using reference lines and angles — here the Perkin and Hilgenreiner lines, the acetabular index (how steep the socket roof is) and Shenton’s line. Alongside the lateral centre-edge angle, these tell us how shallow the socket is and how urgently it needs attention.
X-ray: Ruiz Santiago F, et al., CC BY 4.0, via Wikimedia Commons.
Honest about a structural problem
We’ll be straight with you: physiotherapy cannot deepen the socket or change the shape of the joint. What it can do is often enough to control symptoms, especially in milder and borderline cases — by building the muscles that stabilise an under-covered hip, calming the irritated rim, and managing load so the joint is protected.
Build the stabilisers
A targeted programme for the glutes and deep hip stabilisers helps control the ball in a shallow socket, reducing the rim overload that drives pain — the single most useful thing we can do non-surgically.
Protect and pace the hip
We manage the loads and positions that aggravate it, build tolerance gradually, and track how the hip responds — so you stay active and buy the joint time, while keeping an honest eye on whether a surgical opinion is needed.
Joint-preserving options come first
Because dysplasia is structural, the definitive fix is surgical. The main joint-preserving operation is a periacetabular osteotomy (PAO), which re-orients the socket to cover and support the head and offload the rim. It reliably improves pain and function (Clohisy et al., 2009), and in long-term follow-up of the Bernese technique around 60% of hips were still preserved — no replacement — at 20 years (Steppacher et al., 2008). Keyhole surgery alone is not advised, as it does not fix the lack of cover; for a hip with advanced arthritis, a hip replacement is the answer. We’ll guide you and refer to a specialist hip-preservation surgeon at the right time.
Sources & further reading
Gala L, Clohisy JC, Beaulé PE. Hip dysplasia in the young adult. J Bone Joint Surg Am 2016;98(1):63–73. pubmed.ncbi.nlm.nih.gov
Clohisy JC, Schutz AL, St John L, Schoenecker PL, Wright RW. Periacetabular osteotomy: a systematic literature review. Clin Orthop Relat Res 2009;467(8):2041–2052. pubmed.ncbi.nlm.nih.gov
Steppacher SD, Tannast M, Ganz R, Siebenrock KA. Mean 20-year followup of Bernese periacetabular osteotomy. Clin Orthop Relat Res 2008;466(7):1633–1644. pubmed.ncbi.nlm.nih.gov
Martz P, Magendie J, Ramos-Pascual S, et al. Hip preservation surgery for borderline and frank dysplasia: an overview of systematic reviews. EFORT Open Rev 2024;9(12):1144–1155. doi.org/10.1530/EOR-23-0152
Physiotherapy assessment for hip dysplasia
Your first appointment is a proper assessment, in two parts:
Subjective assessment
A detailed discussion about how it started, what makes it better or worse, how it is affecting your work, training and daily life, and your goals — including any event you are building towards.
Objective assessment
A hands-on examination — strength, movement, loading and specific tests — to pin down the diagnosis and what is driving it. Where it will change your plan, we can arrange diagnostic ultrasound scanning in-house.
Book your hip assessment
If your hip pain may be dysplasia, a thorough assessment gives you a clear picture, a plan to protect and strengthen the joint, and an honest view on whether — and when — a joint-preserving surgical opinion is worth seeking.