Hip Dysplasia

Hip dysplasia means the hip socket (the acetabulum) is too shallow and does not cover enough of the ball (the femoral head). Some people are born with it and are treated as babies, but many teens and adults with dysplasia were never diagnosed until hip pain started. Because the ball is not well covered, the edge of the socket carries too much load, which can lead to labral tears and early arthritis. Dr. Andrew Dold, a board-certified, fellowship-trained sports medicine surgeon in Frisco, Texas, evaluates teens and adults with hip dysplasia and helps them understand their treatment options.

What is hip dysplasia?

The hip is a ball-and-socket joint. Normally, the socket wraps around the ball like a deep cup, spreading your body weight across a wide area of cartilage. In a dysplastic hip, the cup is shallow or tilted, so the weight is concentrated on a small area at the rim of the socket.

The rim of the socket is lined by the labrum, a ring of tough cartilage that seals and deepens the joint. Over time, the extra stress can tear the labrum and wear down the cartilage. Hip dysplasia is a common cause of hip arthritis, and it is found in about 20% to 40% of patients with hip arthritis.¹ More than half of dysplastic hips also have differences in the shape of the thigh bone, so the whole hip needs to be evaluated.¹

Hip dysplasia is more common in girls and women, in firstborn children and in babies born in the breech (bottom-first) position, and it can run in families.² Many adults with dysplasia had no known hip problems as children.

Symptoms

• Pain in the groin or front of the hip, sometimes on the side of the hip or buttock
• Pain that builds with activity, long walks, running or standing for long periods
• Catching, clicking or locking, which may mean a labral tear
• A feeling that the hip is tired, weak or unstable
• A limp after activity
• Pain on the outside of the hip from overworked hip muscles that are trying to stabilize the joint

Pain is often mild and occasional at first, may become more frequent over time, and is often worse with activity or at the end of the day.² Hip pain in a young adult should not be dismissed as a simple muscle strain if it keeps coming back.

Diagnosis

Dr. Dold will ask about your symptoms, activities, childhood hip history and family history, and examine your hip’s motion, strength and stability. Some people with hip pain have the opposite shape problem, where there is too much bone, called femoroacetabular impingement (FAI). Some have features of both, which is why careful measurement matters.

X-rays taken while you are standing are the key test. The most common measurement is the lateral center-edge angle (LCEA). Imagine a line straight up from the center of the ball, and a second line from the center of the ball to the outer edge of the socket. The angle between them shows how far the roof of the socket reaches over the ball. A smaller angle means less coverage. Many studies define an LCEA under about 20° as dysplasia and 20° to 25° as “borderline” dysplasia, although the exact cutoffs vary from study to study.³ Other X-ray measurements look at the slope of the socket roof and the coverage at the front and back of the hip.

An MRI can show labral tears and cartilage damage. A CT scan is sometimes used to measure the 3-D shape of the socket and the twist of the thigh bone, which helps with surgical planning.

Non-surgical treatment

Treatment depends on your symptoms, your age, how shallow the socket is, and whether arthritis is already present. Non-surgical care may help, especially for mild symptoms:

• Physical therapy to strengthen the muscles around the hip and core, which help stabilize the joint
• Activity changes, such as limiting high-impact activities, very deep hip bending and long periods of standing if they cause pain, while staying active with lower-impact exercise
• Anti-inflammatory medicines for flare-ups
• Injections into the hip joint, which can relieve pain and can help confirm that the pain is coming from inside the joint

These treatments can relieve symptoms, but they do not change the shape of the socket.

Surgical options

Periacetabular osteotomy (PAO). A PAO is an open operation in which the surgeon makes controlled cuts in the pelvis around the socket, rotates the socket into a position that better covers the ball, and holds it with screws while the bone heals. The goal is to spread the load across healthier cartilage and protect the hip from arthritis. PAO is generally recommended for younger patients with symptomatic dysplasia and little or no arthritis. Acetabular osteotomy is the most commonly used procedure for most dysplastic hips in adults.¹ It is a specialized procedure, and Dr. Dold will discuss whether you are a candidate and refer you when appropriate to a surgeon who performs it.

Long-term results depend heavily on choosing the right patient. In the original group of 75 hips treated with PAO in the mid-1980s, about 29% still met a strict definition of success at 30 years: no hip replacement, no worsening of arthritis on X-ray, and good hip function.⁴ Hips did worse when patients were over 40 at the time of surgery or already had arthritis.⁴ Surgical techniques and patient selection have improved since that early series. Individual results vary.

Hip arthroscopy. In hip arthroscopy, the surgeon uses a small camera and instruments through tiny incisions to repair a torn labrum and treat cartilage or bone problems. In true dysplasia, arthroscopy alone does not fix the shallow socket. A systematic review of 889 patients found that most studies reported improvement after arthroscopy in dysplastic hips, but 14.1% needed another operation and 9.6% went on to hip replacement.³ Arthroscopy may be an option for selected patients with borderline dysplasia, usually with careful repair or tightening of the joint capsule, or it may be combined with a PAO to treat a labral tear at the same time. For more, see our hip arthroscopy and FAI questions.

Hip replacement. Once arthritis is advanced, reshaping the socket is no longer helpful, and total hip replacement is an option for relieving pain and restoring function.¹ Dysplastic hips can be more complex to replace because of the unusual shape of the socket and thigh bone, so careful planning is important. Learn more about anterior hip replacement and hip arthritis.

Recovery and return to activity

Recovery depends on the treatment. Physical therapy programs usually take several months. After a PAO, patients usually stay in the hospital for a few days and limit weight on the leg, using crutches, for about 6 to 12 weeks while the bones heal,² followed by a gradual strengthening program; return to sports often takes several months or longer. Recovery after hip arthroscopy and hip replacement is usually faster. Your surgeon will give you a plan specific to your procedure. Individual results vary.

What the research shows

• Dysplasia speeds up arthritis: long-term studies show that hips with dysplasia develop wear faster than hips with normal shape or impingement. Once early arthritis appears, about two in three dysplastic hips needed a replacement within 20 years in one large study, which is why timing of treatment matters.
• Diagnosis needs more than one number: the lateral center-edge angle is the standard measurement, but reviews recommend combining it with other X-ray and MRI measurements, because borderline cases are common.
• PAO for true dysplasia: repositioning the socket with a periacetabular osteotomy improves pain and function and can preserve the natural hip for decades, with more favorable results when arthritis is minimal and the socket is corrected to the target position. Carefully selected patients over 40 can also do well.
• Arthroscopy alone has limits: for borderline dysplasia, hip arthroscopy with careful capsule repair can give results similar to patients without dysplasia, but reoperation rates are higher. In moderate to severe dysplasia, arthroscopy alone tends to fail and can make the hip unstable.
• Non-surgical care: strengthening the muscles around the hip and core, and modifying high-impact activity, help many patients, especially with milder symptoms.
• When arthritis is advanced, hip replacement reliably relieves pain. Revision rates are somewhat higher than for ordinary arthritis because the anatomy is more complex.

Why see Dr. Dold

• Board certified by the American Board of Orthopaedic Surgery, with subspecialty certification in Sports Medicine
• Sports medicine and arthroscopy fellowship at NYU Langone / Hospital for Joint Diseases; orthopedic residency at the University of Toronto
• Fellow of the American College of Surgeons (FACS), the American Academy of Orthopaedic Surgeons (FAAOS), the American Orthopaedic Association (FAOA) and the Royal College of Surgeons of Canada (FRCSC)
• Published research on hip arthroscopy, including Post-operative Considerations Following Hip Arthroscopy (JBJS Reviews, 2017) and studies in the American Journal of Sports Medicine; member of the International Society for Hip Arthroscopy (ISHA)
• Team physician and surgical consultant to Rugby Canada; has cared for professional athletes from the NFL, NBA, NHL, MLS, PGA Tour and Major League Rugby
• D Magazine Best Doctors (Collin County), 2019–2026 · Rated 4.9 on Google

Frequently asked questions

Research cited on this page

1. Gala L, Clohisy JC, Beaulé PE. Hip dysplasia in the young adult. J Bone Joint Surg Am. 2016;98(1):63-73. Abstract
2. American Academy of Orthopaedic Surgeons. Adolescent hip dysplasia. OrthoInfo. orthoinfo.org
3. Yeung M, Kowalczuk M, Simunovic N, et al. Hip arthroscopy in the setting of hip dysplasia: a systematic review. Bone Joint Res. 2016;5(6):225-231. PubMed
4. Lerch TD, Steppacher SD, Liechti EF, et al. One-third of hips after periacetabular osteotomy survive 30 years with good clinical results, no progression of arthritis, or conversion to THA. Clin Orthop Relat Res. 2017;475(4):1154-1168. PubMed
5. O’Connor KP, Marshall BJ, Davison J, et al. Prevalence of Radiographic Hip Dysplasia in the General Adult Population: A Systematic Review. Iowa Orthop J. 2024;44(1):145-149. PubMed
   Systematic review: radiographic acetabular dysplasia is relatively common in adults and more common in women.
6. Kraeutler MJ, Safran MR, Scillia AJ, et al. A Contemporary Look at the Evaluation and Treatment of Adult Borderline and Frank Hip Dysplasia. Am J Sports Med. 2020;48(9):2314-2323. PubMed
   Review: the lateral center-edge angle is the most common diagnostic measure but is unreliable alone; additional measurements should be used.
7. Wyles CC, Heidenreich MJ, Jeng J, et al. The John Charnley Award: Redefining the Natural History of Osteoarthritis in Patients With Hip Dysplasia and Impingement. Clin Orthop Relat Res. 2017;475(2):336-350. PubMed
   Natural history study: degenerative change progressed fastest in dysplastic hips; about two in three needed hip replacement within 20 years of early arthritis.
8. Wyles CC, Vargas JS, Heidenreich MJ, et al. Natural History of the Dysplastic Hip Following Modern Periacetabular Osteotomy. J Bone Joint Surg Am. 2019;101(10):932-938. PubMed
   Natural history after PAO: higher initial arthritis grade increased the risk of progression to hip replacement.
9. Wyles CC, Vargas JS, Heidenreich MJ, et al. Hitting the Target: Natural History of the Hip Based on Achieving an Acetabular Safe Zone Following Periacetabular Osteotomy. J Bone Joint Surg Am. 2020;102(19):1734-1740. PubMed
   Study: achieving the target socket correction after PAO greatly prolonged time without arthritis progression.
10. Siebenrock KA, Schöll E, Lottenbach M, et al. Bernese periacetabular osteotomy. Clin Orthop Relat Res. 1999(363):9-20. PubMed
    Bernese PAO series: the hip was preserved in 82% at follow-up; poorer outcomes with older age, arthritis and labral lesions.
11. Clohisy JC, Schutz AL, St John L, et al. Periacetabular osteotomy: a systematic literature review. Clin Orthop Relat Res. 2009;467(8):2041-52. PubMed
    Systematic review: PAO improved pain and function; failures were associated with moderate to severe arthritis before surgery.
12. Tan SHS, Tan JHI, Lim AKS, et al. Periacetabular osteotomy for acetabular retroversion: A systematic review and meta-analysis. Orthop Traumatol Surg Res. 2021;107(8):103078. PubMed
    Meta-analysis: PAO for dysplasia showed long survival times with low rates of major complications.
13. Albers CE, Steppacher SD, Ganz R, et al. Impingement adversely affects 10-year survivorship after periacetabular osteotomy for DDH. Clin Orthop Relat Res. 2013;471(5):1602-14. PubMed
    Study: impingement after PAO reduced 10-year survivorship; age, arthritis and under- or over-correction predicted failure.
14. Stetzelberger VM, Leibold CS, Steppacher SD, et al. The Acetabular Wall Index Is Associated with Long-term Conversion to THA after PAO. Clin Orthop Relat Res. 2021;479(5):1052-1065. PubMed
    Long-term study: a deficient anterior wall was associated with conversion to hip replacement after PAO.
15. O’Connor KP, Ince DJ, Clohisy JC, et al. Hip Dysplasia Treated With Periacetabular Osteotomy in Patients Over 40 Years Old: A Systematic Review. Iowa Orthop J. 2024;44(1):105-112. PubMed
    Systematic review: carefully selected patients over 40 can still do well after PAO.
16. Muffly BT, Zacharias AJ, Jochimsen KN, et al. Age at the Time of Surgery Is Not Predictive of Early Patient-Reported Outcomes After Periacetabular Osteotomy. J Arthroplasty. 2021;36(10):3388-3391. PubMed
    Cohort: age alone did not predict poorer outcomes after PAO.
17. Ross JR, Clohisy JC, Baca G, et al. Patient and disease characteristics associated with hip arthroscopy failure in acetabular dysplasia. J Arthroplasty. 2014;29(9 Suppl):160-3. PubMed
    Multicenter cohort: labral and cartilage damage were common at the time of PAO.
18. Redmond JM, Gupta A, Stake CE, et al. The prevalence of hip labral and chondral lesions identified by method of detection during periacetabular osteotomy: arthroscopy versus arthrotomy. Arthroscopy. 2014;30(3):382-8. PubMed
    Systematic review: intra-articular damage is common at PAO and better recognized with combined arthroscopy.
19. Leopold VJ, Poitras S, Clohisy JC, et al. Recovery trajectory and patient-specific predictors following periacetabular osteotomy : a 24-month prospective study. Bone Joint J. 2026;108-B(5):607-615. PubMed
    Multicenter cohort: most PAO patients improved within the first year, with further gains in the second.
20. Lodhia P, Chandrasekaran S, Gui C, et al. Open and Arthroscopic Treatment of Adult Hip Dysplasia: A Systematic Review. Arthroscopy. 2016;32(2):374-83. PubMed
    Review: arthroscopy improved outcomes in borderline dysplasia (center-edge angle about 18–25 degrees), while PAO is the main treatment for true dysplasia.
21. Shah A, Kay J, Memon M, et al. Clinical and radiographic predictors of failed hip arthroscopy in the management of dysplasia: a systematic review and proposal for classification. Knee Surg Sports Traumatol Arthrosc. 2020;28(4):1296-1310. PubMed
    Systematic review: arthroscopy gives good results in mild dysplasia without severe cartilage damage but tends to fail in moderate to severe dysplasia.
22. Krivicich LM, Rice M, Sivasundaram L, et al. Borderline Dysplastic Hips Undergoing Hip Arthroscopy Achieve Equivalent Patient Reported Outcomes When Compared With Hips With Normal Acetabular Coverage: A Systematic Review and Meta-Analysis. J Am Acad Orthop Surg. 2023;31(6):e336-e346. PubMed
    Meta-analysis: patients with borderline dysplasia reached outcomes similar to non-dysplastic patients after arthroscopy at short-term follow-up.
23. Barton C, Scott E, Khazi ZM, et al. Outcomes of Surgical Management of Borderline Hip Dysplasia: A Systematic Review. Iowa Orthop J. 2019;39(2):40-48. PubMed
    Systematic review: arthroscopy for borderline dysplasia improved scores, but reoperation rates were high.
24. Dhillon J, Ansari M, Keeter C, et al. Periacetabular osteotomy with or without hip arthroscopy in patients with borderline hip dysplasia: A systematic review. Knee Surg Sports Traumatol Arthrosc. 2025;33(12):4221-4233. PubMed
    Systematic review: PAO for borderline dysplasia gave consistent improvement with low reoperation and conversion rates.
25. Ortiz-Declet V, Mu B, Chen AW, et al. Should the Capsule Be Repaired or Plicated After Hip Arthroscopy for Labral Tears Associated With Femoroacetabular Impingement or Instability? A Systematic Review. Arthroscopy. 2018;34(1):303-318. PubMed
    Systematic review: capsular closure after hip arthroscopy is safe and may improve outcomes, supporting closure in at-risk hips.
26. Yeung M, Memon M, Simunovic N, et al. Gross Instability After Hip Arthroscopy: An Analysis of Case Reports Evaluating Surgical and Patient Factors. Arthroscopy. 2016;32(6):1196-1204.e1. PubMed
    Systematic review: dysplasia, female sex and ligamentous laxity are risk factors for instability after hip arthroscopy.
27. Hölmich P, Thorborg K, Nyvold P, et al. Does bony hip morphology affect the outcome of treatment for patients with adductor-related groin pain? Outcome 10 years after baseline assessment. Br J Sports Med. 2014;48(16):1240-4. PubMed
    Randomized trial: hip shape related to dysplasia did not prevent success of an exercise program for groin pain.
28. Salman LA, Alzobi OZ, Al-Ani A, et al. The outcomes of total hip arthroplasty in developmental dysplasia of hip versus osteoarthritis: a systematic review and meta-analysis. Eur J Orthop Surg Traumatol. 2024;34(1):1-8. PubMed
    Meta-analysis: hip replacement for dysplasia had a higher revision rate than for ordinary arthritis but similar dislocation, loosening and infection rates.

Medically reviewed by Andrew P. Dold, MD, FAOA, FAAOS, FACS, FRCSC. Last reviewed October 2026. This page is general information, not medical advice. Individual results vary.