Borderline hip dysplasia: Definition, Uses, and Clinical Overview

Posted on February 27, 2026 | by drhip

Borderline hip dysplasia Introduction (What it is)

Borderline hip dysplasia is a term used when the hip socket provides slightly reduced coverage of the femoral head.
It sits between a clearly normal hip and more definite (frank) acetabular dysplasia.
Clinicians commonly use it when evaluating hip pain, clicking, instability sensations, or labral problems.
It is most often discussed in orthopedics, sports medicine, hip preservation clinics, and physical therapy.

Why Borderline hip dysplasia used (Purpose / benefits)

Borderline hip dysplasia is not a treatment by itself—it is a diagnostic and classification concept that helps clinicians describe hip shape and guide decision-making.

In simple terms, the “ball-and-socket” hip joint works best when the socket (acetabulum) covers the ball (femoral head) well enough to provide stability, distribute load, and protect cartilage and the labrum. When socket coverage is reduced, contact forces and motion patterns can change. In some people, that may contribute to symptoms such as groin pain, mechanical catching, or a feeling that the hip is unstable.

Using the term Borderline hip dysplasia helps clinicians:

Communicate severity when the hip is not clearly normal but also not severely dysplastic.
Frame the likely pain mechanisms, such as microinstability (subtle extra motion) versus impingement-driven pain.
Plan appropriate imaging and interpret X-rays and MRI findings in context.
Discuss management pathways, which may include activity modification, targeted rehabilitation, injections for diagnostic clarification, or surgery in selected cases.
Set expectations that symptoms and best-fit interventions can vary substantially by anatomy, activity demands, and associated injuries.

Because “borderline” sits in a gray zone, its main benefit is clarifying that the hip may require a more individualized evaluation than a purely “normal” hip.

Indications (When orthopedic clinicians use it)

Clinicians commonly consider or document Borderline hip dysplasia in scenarios such as:

Hip or groin pain during sport, running, pivoting, prolonged sitting, or stairs
Mechanical symptoms (clicking, catching) suggestive of labral involvement
Sensation of giving way, shifting, or subtle instability (often called microinstability)
MRI findings such as a labral tear, cartilage wear, or capsular laxity where bony coverage may be relevant
A history of generalized joint laxity or hypermobility features (varies by clinician and case)
Abnormal hip range of motion patterns, weakness, or poor pelvic control noted on exam
Preoperative planning when considering hip arthroscopy, periacetabular osteotomy (PAO), or other hip preservation approaches

Contraindications / when it’s NOT ideal

Because Borderline hip dysplasia is a descriptive diagnosis rather than a treatment, “contraindications” usually refer to when the label is less helpful or when a different framework better explains the problem. Situations where Borderline hip dysplasia may not be the best primary explanation include:

Clearly normal acetabular coverage on a well-positioned pelvic radiograph (the symptoms may be from another source)
Frank (more severe) acetabular dysplasia, where the clinical discussion often shifts away from “borderline” terminology
Advanced osteoarthritis, where joint degeneration may drive symptoms more than subtle coverage differences (management considerations can differ)
Referred pain patterns (lumbar spine, sacroiliac joint, abdominal/pelvic sources) that better match the presentation
Acute fracture, infection, tumor, or inflammatory arthritis concerns, where urgent diagnostic pathways apply
Poor-quality or malpositioned imaging, where measurements can be misleading and should be repeated or confirmed (varies by clinician and case)

In practice, clinicians often pair imaging findings with symptoms and examination findings to decide whether Borderline hip dysplasia is clinically meaningful for that patient.

How it works (Mechanism / physiology)

Borderline hip dysplasia describes a biomechanical relationship between the acetabulum and femoral head rather than a biologic process like inflammation or infection.

Core principle: coverage and load distribution

When acetabular coverage is reduced, forces may concentrate over a smaller contact area of cartilage. Depending on the individual’s movement patterns and tissue resilience, this can contribute to:

Labral overload: The labrum is a ring of fibrocartilage around the socket rim that helps seal the joint and add stability. Increased rim loading can irritate or tear it.
Cartilage stress: Articular cartilage lines the socket and femoral head. Altered contact mechanics may increase focal wear over time (the pace varies by clinician and case).
Microinstability: Subtle extra motion of the femoral head within the socket, sometimes associated with symptoms during extension, external rotation, or pivoting.

Relevant hip anatomy

Key structures commonly discussed with Borderline hip dysplasia include:

Acetabulum (socket): Its depth and orientation influence how much of the femoral head is covered.
Femoral head and neck (ball and connecting segment): Shape and version can influence motion and impingement tendencies.
Labrum: Helps with stability and joint sealing; commonly symptomatic when stressed.
Capsule and ligaments: The hip capsule contributes to stability; laxity or surgical over-release can influence symptoms (varies by clinician and case).
Cartilage: Sensitive to abnormal loading patterns and injury.

Onset, duration, and reversibility

Borderline hip dysplasia is generally considered a structural anatomy descriptor. It does not “start” suddenly like an injury, though symptoms can begin abruptly after increased activity, a minor injury, or a change in training load. The bony shape itself does not reverse without surgery, but symptoms can fluctuate based on strength, movement strategy, inflammation, and coexisting conditions.

Borderline hip dysplasia Procedure overview (How it’s applied)

Borderline hip dysplasia is not a single procedure. It is applied as part of a clinical evaluation and can influence which tests or interventions are considered. A typical workflow looks like this:

Evaluation / exam – History: location of pain (often groin), triggers, mechanical symptoms, instability sensations, prior injuries, activity demands – Physical exam: hip range of motion, impingement-type maneuvers, instability-focused tests, strength and pelvic control assessment, gait observation
Preparation – Selection of appropriate imaging based on presentation (often starting with X-rays) – Ensuring imaging is obtained with standardized positioning when possible, because pelvic tilt/rotation can affect measurements
Intervention / testing – Imaging interpretation: clinicians may use radiographic measures of coverage and orientation. Borderline categories are commonly associated with measures such as the lateral center-edge angle (LCEA) in a borderline range (often cited around the low-20-degree range), but exact cutoffs vary by clinician and case. – MRI or MR arthrogram may be used to evaluate the labrum, cartilage, and surrounding soft tissues when indicated. – Diagnostic injection (local anesthetic with or without corticosteroid) may be used in some practices to help determine whether pain is intra-articular (varies by clinician and case).
Immediate checks – Correlating imaging findings with symptoms and exam results – Screening for alternative or coexisting diagnoses (lumbar spine, core muscle injury, tendon disorders)
Follow-up – Reassessment after a period of rehabilitation, activity adjustment, or additional testing – If surgery is considered, further planning may include advanced imaging and detailed risk–benefit discussion (varies by clinician and case)

Types / variations

Borderline hip dysplasia is best understood as a spectrum rather than a single uniform condition. Common variations include:

Radiographic “borderline” by LCEA
Many clinicians use LCEA as a primary descriptor of lateral coverage.
The “borderline” range is commonly referenced in the low-to-mid 20° range, but definitions differ across practices and publications (varies by clinician and case).
Anterior vs lateral undercoverage
Some hips have more deficiency in front (anterior) rather than on the side (lateral), which may change symptom patterns and surgical planning considerations.
Version-related patterns
Acetabular or femoral version (twist/orientation) can influence whether symptoms resemble instability, impingement, or a mix.
Borderline dysplasia with femoroacetabular impingement (FAI) features
Some patients have both reduced coverage and bony shape features that can cause impingement. This combination can complicate interpretation and treatment selection (varies by clinician and case).
Stable borderline vs unstable borderline (clinical concept)
Two people with similar X-ray angles can have very different stability depending on soft tissues, activity demands, and neuromuscular control.
Symptomatic vs incidental
Borderline features may be seen on imaging even when symptoms are driven primarily by another issue.

Pros and cons

Pros:

Helps describe a “gray zone” hip shape that is not clearly normal or clearly dysplastic
Encourages careful correlation of imaging with symptoms and physical exam
Prompts a broader differential diagnosis (instability, impingement, labral pain, extra-articular sources)
Can guide selection of imaging views and measurements for more complete assessment
Supports clearer communication among orthopedic surgeons, radiologists, and therapists
Helps frame why similar-looking labral tears may behave differently across patients

Cons:

Definitions and cutoff values vary across clinicians and imaging techniques
Measurements can change with pelvic positioning and radiograph quality
The label does not specify the pain generator (labrum vs cartilage vs capsule vs tendon)
Risk of over-attributing symptoms to imaging findings that may be incidental
Mixed presentations (e.g., instability plus impingement features) can be difficult to categorize
Management pathways can be less standardized than for frank dysplasia or classic FAI

Aftercare & longevity

Because Borderline hip dysplasia is a diagnosis rather than a treatment, “aftercare” and “longevity” depend on what management approach is used and what structures are involved (labrum, cartilage, capsule, muscle control). In general, outcomes and symptom durability are influenced by:

Severity and pattern of undercoverage (lateral, anterior, combined) and associated version/orientation factors
Presence and extent of cartilage damage on imaging or at surgery (if performed), which can affect longer-term joint health
Labral condition (irritation vs tear, tissue quality) and how it relates to stability mechanics
Neuromuscular control and strength, especially hip abductors, deep rotators, trunk control, and movement strategy (often addressed in rehab programs)
Activity demands and load exposure, including high-impact sport, pivoting, and occupational lifting requirements
Coexisting conditions, such as hypermobility spectrum features, lumbar pathology, or tendon disorders (varies by clinician and case)
Follow-up consistency, reassessment, and adjustments to the plan as symptoms change over time

If surgical options are used (in selected cases), longevity can also relate to procedure selection, tissue healing biology, and adherence to the surgeon’s rehabilitation protocol (specific timelines vary by surgeon and case).

Alternatives / comparisons

Because Borderline hip dysplasia is a classification that can lead to different management strategies, comparisons are usually between evaluation/monitoring, non-surgical symptom management, and surgical hip preservation pathways.

Observation / monitoring
Often used when imaging shows borderline features but symptoms are mild, intermittent, or not clearly hip-joint–driven.
Focus is typically on tracking symptom pattern and function over time.
Physical therapy / rehabilitation-focused care
Commonly used to address strength, control, and movement patterns that can influence hip loading and perceived stability.
May be emphasized when symptoms suggest microinstability or overload rather than a purely mechanical block.
Medication (symptom control)
Non-prescription or prescription anti-inflammatory medications may be discussed for short-term symptom modulation in some cases (appropriateness varies by clinician and patient factors).
Medication does not change bony coverage.
Injections
Intra-articular injections may be used diagnostically (to see if numbing the joint reduces pain) and/or therapeutically to calm symptoms.
Response can help clarify pain source but does not by itself define the ideal long-term approach (varies by clinician and case).
Hip arthroscopy
Often discussed when labral pathology is prominent.
In borderline coverage situations, clinicians may weigh stability risks and the importance of capsular management; appropriateness varies by clinician and case.
Periacetabular osteotomy (PAO) or other reorientation procedures
Often associated with more definitive dysplasia but may be considered in selected borderline cases, particularly when instability and structural undercoverage are key drivers.
This is a major reconstructive procedure and is not interchangeable with arthroscopy; decision-making is individualized.

A common clinical challenge is distinguishing when symptoms are primarily driven by instability/undercoverage versus impingement morphology or soft-tissue overload, since the best-matched approach can differ.

Borderline hip dysplasia Common questions (FAQ)

Q: Is Borderline hip dysplasia the same as hip dysplasia?
Borderline hip dysplasia is generally considered a milder or intermediate category between normal coverage and more definite acetabular dysplasia. The term usually signals that measurements are near a threshold and must be interpreted with symptoms and exam findings. Exact definitions vary by clinician and case.

Q: Can Borderline hip dysplasia cause pain even if X-rays look “almost normal”?
Yes, some people have significant symptoms with subtle structural differences, while others have borderline measurements and little to no pain. Pain can come from the labrum, cartilage, capsule, or surrounding tendons, and imaging findings need clinical correlation. Symptom severity does not always match a single angle or measurement.

Q: What symptoms are commonly associated with Borderline hip dysplasia?
Commonly reported symptoms include groin pain, pain with prolonged sitting or activity, clicking/catching, and sometimes a feeling of instability or “giving way.” Some people also report lateral hip or buttock discomfort, which can overlap with tendon or spine-related pain patterns. Presentation varies by clinician and case.

Q: How is Borderline hip dysplasia diagnosed?
Diagnosis usually involves a history and physical exam plus pelvic and hip X-rays with specific views. Clinicians may use measurements such as the lateral center-edge angle and other indicators of coverage and orientation, and MRI may be used to assess the labrum and cartilage. Because positioning affects measurements, image quality and technique matter.

Q: Does Borderline hip dysplasia mean I will need surgery?
Not necessarily. Many cases are managed without surgery, especially when symptoms are mild or respond to rehabilitation and activity adjustments. When surgery is considered, the type depends on the dominant problem pattern (for example, instability/undercoverage versus labral pathology), and decision-making varies by clinician and case.

Q: What is the recovery like if a procedure is done for issues related to Borderline hip dysplasia?
Recovery depends on the specific intervention—rehabilitation-only pathways differ from injections, arthroscopy, or socket reorientation procedures. Timelines, weight-bearing status, and return-to-work expectations can vary widely by procedure and surgeon protocol. A clinician typically outlines expectations based on the exact plan and findings.

Q: Can I drive or work if I have Borderline hip dysplasia?
Many people continue to drive and work, but tolerance depends on pain level, sitting demands, and job tasks. After injections or surgery, restrictions may apply for safety reasons and can vary by clinician and case. Functional decisions are usually individualized.

Q: How long do results last with non-surgical care?
Symptom improvement may last as long as contributing factors (strength, movement patterns, load management, and tissue irritability) remain well controlled. Some people have long periods of stability, while others have recurring flares with activity changes or progressive tissue changes. Duration varies by clinician and case.

Q: Is Borderline hip dysplasia “dangerous” or unsafe to live with?
Borderline hip dysplasia is a structural descriptor, not an emergency diagnosis. The main clinical concern is whether the anatomy and mechanics contribute to symptoms or to tissue overload over time. Risk and progression are individualized and depend on many factors, including cartilage health and activity demands.

Q: How much does evaluation or treatment typically cost?
Costs vary widely by region, insurance coverage, imaging needs, and whether care involves therapy, injections, or surgery. Out-of-pocket expenses can differ substantially between clinic visits, advanced imaging, and procedural care. For any individual case, costs are best clarified through the treating facility and payer.