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Femoroacetabular Impingement (FAI)
When Hip Movement Meets Resistance
Femoroacetabular impingement (FAI) is a condition where abnormal bone shapes in the hip joint cause friction during movement—leading to pain, stiffness, and potential joint damage. Whether caused by a cam or pincer lesion, FAI can limit your ability to stay active, especially in sports or jobs that require deep hip flexion.
Learn what causes FAI, how to recognize the symptoms, and which treatments—including advanced hip arthroscopy—can help you move freely again.
What Is Femoroacetabular Impingement (FAI)?
Femoroacetabular impingement (FAI) is a condition in which extra bone develops along one or both surfaces of the hip joint, causing the ball (femoral head) and socket (acetabulum) to rub together abnormally. Over time, this irregular contact creates friction, leading to damage of the joint cartilage and the labrum—a ring of tissue that helps stabilize the hip.
This mechanical conflict between bone structures limits smooth joint movement and often results in pain, stiffness, and inflammation during activities that require deep hip flexion, such as squatting, dancing, hockey, or soccer.
Types of FAI
There are three primary types of femoroacetabular impingement:
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Cam Impingement: An extra bony bump on the femoral head causes it to jam into the socket during movement.
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Pincer Impingement: The socket covers too much of the femoral head or is angled abnormally, leading to pinching of soft tissues.
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Combined FAI: A mix of cam and pincer abnormalities—common in athletes and highly active individuals.
🔍 Left untreated, FAI can lead to labral tears, cartilage wear, and eventually early-onset hip arthritis.
Understanding Normal Hip Anatomy
The hip is one of the most powerful and stable joints in the body. It’s a ball-and-socket joint, where the rounded femoral head (the top of the thigh bone) fits into the acetabulum, a deep socket in the pelvis.
When the joint is healthy, this design allows for smooth, pain-free motion in nearly every direction—from walking and running to sitting and squatting.
🧬 Support Structures of the Hip
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Labrum: A ring of cartilage that seals the joint and enhances stability
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Joint capsule: A fibrous sleeve that protects the joint and contains synovial fluid
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Articular cartilage: A smooth coating on the femoral head and socket that reduces friction
These elements work together to protect the joint from damage, even under high loads and frequent use.
Why This Matters in FAI
In femoroacetabular impingement, abnormal bone shapes disrupt the natural fit and movement of the hip. Instead of gliding smoothly, the ball grinds against the socket—especially during movements like bending, pivoting, or squatting.
Understanding normal hip structure makes it easier to see how FAI leads to pain, damage, and reduced mobility.
Causes of Hip Impingement (FAI)
Femoroacetabular impingement (FAI) occurs when the bony structures of the hip joint develop in a way that disrupts smooth movement. This abnormal contact between the femoral head and the acetabulum leads to friction, labral tears, and cartilage breakdown.
Most causes of FAI are structural and may be present from adolescence, but symptoms often develop later—especially with activity or injury.
Primary Structural Causes
Cam Lesion
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A bump or overgrowth on the femoral head causes it to jam into the socket during movement
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Common in active adolescents during bone growth
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Seen frequently in athletes (especially male)
Pincer Lesion
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The acetabulum (socket) covers too much of the femoral head or is abnormally angled
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Causes pinching of the labrum and soft tissue
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More common in women and dancers
Combined Impingement
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Many patients have both cam and pincer abnormalities
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This is the most common presentation in high-level athletes, especially in sports like hockey, soccer, and ballet
Contributing Factors
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Genetic bone shape or alignment issues
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Repetitive deep hip motion (e.g., squats, lunges, pivots)
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High-impact sports during growth years
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Femoral retroversion or excessive anteversion (twisting of the femur)
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Poor biomechanics or muscular imbalances that increase joint stress
FAI is not caused by poor posture or flexibility—it’s a structural condition that can worsen with movement, not a soft tissue strain.
🏒 Athletes: Protect Your Hips Before It Becomes FAI
Repetitive motion sports like hockey, dance, and soccer can contribute to femoroacetabular impingement over time.
Learn how to stay ahead of the pain in our blog: Preventing Hip Pain in Young Athletes: A Comprehensive Guide ›
Who Is at Risk for Femoroacetabular Impingement (FAI)?
FAI often starts developing during adolescence, especially in active individuals whose bones are still forming. However, many people don’t realize they have it until symptoms appear in their teens, 20s, or 30s—usually triggered by activity, growth, or injury.
Common Risk Groups
⚽ Young Athletes
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Repetitive deep hip motion (squatting, pivoting, jumping)
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Sports like hockey, soccer, dance, football, and CrossFit
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Growth plates may shape abnormally under high stress
🧬 People with Structural Bone Variants
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Cam or pincer bone shapes can be present from birth or develop with age
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May go undetected without imaging
🚹 Gender Differences
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Cam-type FAI is more common in young men
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Pincer-type FAI is more common in young women, especially dancers and gymnasts
🧍♂️ Adults with Unresolved Hip Pain
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If you’ve been diagnosed with a labral tear, tendinitis, or “tight hips,” FAI might be the underlying cause
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Common in people who’ve had years of undiagnosed groin pain or stiffness
Key Insight:
Many patients with FAI are misdiagnosed for years. The key is to recognize the risk factors early—before repetitive impingement leads to labral tears or arthritis.
If you’re an athlete, have hip pain with movement, or were told you have a labral tear without a clear cause—FAI may be the reason.
Common Symptoms of Femoroacetabular Impingement (FAI)
FAI symptoms often develop gradually, especially in active individuals. The friction between the femoral head and the acetabulum becomes more damaging over time—especially during movements like squatting, sitting, or rotating the hip.
🔍 Typical Symptoms of FAI:
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Deep groin pain, especially during or after activity
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Clicking, catching, or locking sensations in the hip
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Pain with prolonged sitting or deep hip flexion (e.g., driving, tying shoes)
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Stiffness or reduced hip range of motion
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Pain radiating to the outer hip, thigh, or buttock
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Feeling like your hip is “pinching” or “jamming” during motion
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Worsening pain with activities like running, pivoting, or squatting
When to Seek Evaluation
Many FAI patients are initially misdiagnosed with:
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Labral tears without clear cause
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Hip flexor or groin strains
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“Tight hips” or nonspecific impingement
If your hip pain hasn’t improved with stretching, rest, or physical therapy, it may be time to look deeper.
💬 At HipPreservation.org, we specialize in evaluating complex hip pain and uncovering the root cause—before long-term damage occurs.
✅ FAI (Hip Impingement) Symptom Self-Checklist
Check all that apply to your experience. If you check more than two, it may be time to consult a hip specialist for further evaluation.
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☐ Deep pain in the front of the hip or groin, especially after activity
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☐ Clicking, catching, or popping sensation inside the hip
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☐ Pain with sitting for long periods (e.g., driving, working at a desk)
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☐ Difficulty with deep squats, lunges, or tying your shoes
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☐ Hip stiffness or decreased range of motion
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☐ Pain with pivoting, twisting, or changing direction suddenly
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☐ You’ve been told you have a labral tear or hip strain without a clear cause
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☐ Pain that hasn’t improved with rest, stretching, or physical therapy
How Is FAI Diagnosed?
Diagnosing femoroacetabular impingement (FAI) requires a thorough understanding of both hip structure and movement mechanics. Because symptoms often mimic other conditions—like strains or tendinitis—accurate diagnosis is essential to avoid delay and prevent long-term joint damage.
At HipPreservation.org, we combine physical assessment with advanced imaging to uncover the root cause of your hip pain.
🔍 The FAI Diagnostic Process
1. Medical History & Symptom Review
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Type, location, and duration of hip pain
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Triggers (e.g., squatting, sitting, running)
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Prior diagnoses (labral tear, groin strain, etc.)
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Athletic history or repetitive motion activities
2. Physical Examination
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Assess hip flexibility, joint range of motion, and pain response
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Perform special tests to provoke impingement
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Evaluate for signs of labral tears or instability
3. Imaging Studies
Imaging helps confirm the diagnosis and determine the severity of structural damage:
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X-rays: To detect cam or pincer bone overgrowth
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MRI or MR arthrogram: To visualize soft tissue damage (labral tears, cartilage wear)
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CT scan (if needed): For 3D evaluation of bone shape or surgical planning
🎥 Want to better understand your own hip images?
👉 Read our guide: Understanding Your Hip X-Rays – A Patient’s Guide ›
Learn how to interpret common imaging findings and see examples of what FAI may look like on X-ray.
💡 What We’re Looking For:
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Cam or pincer morphology
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Loss of femoral head clearance during flexion
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Labral damage or early cartilage breakdown
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Femoral version abnormalities (if DFO might be needed)
Many patients with chronic hip pain are told they have a “tight hip” or a “strained muscle.” FAI requires detailed imaging to diagnose and treat properly.
Treatment Options for Femoroacetabular Impingement
The right treatment for FAI depends on your age, activity level, type of impingement, and how much damage exists inside the joint. Early or mild cases can often be managed without surgery. When pain persists or the joint is at risk, surgery may be needed to restore normal hip mechanics.
Non-Surgical Treatment Options
For patients with mild symptoms or early-stage impingement, we may recommend:
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Activity Modification: Avoiding movements that aggravate symptoms (deep squats, lunges, etc.)
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Physical Therapy: Strengthening the muscles around the hip and improving joint control
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Anti-inflammatory medications: Short-term use to reduce swelling and pain
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Injections: Corticosteroids or platelet-rich plasma (PRP) to reduce inflammation or confirm diagnosis
These strategies won’t reverse the bone abnormality but may reduce symptoms for a time—especially in less active patients.
🔧 Surgical Treatment Options
When conservative treatments fail—or when imaging shows labral or cartilage damage—surgery may be needed to correct the structural issue.
1. Hip Arthroscopy
A minimally invasive procedure performed through small incisions to:
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Repair labral tears
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Reshape the femoral head or acetabulum (to eliminate cam/pincer lesions)
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Smooth or regenerate damaged cartilage
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Improve joint clearance and biomechanics
✅ Best for patients under 50 with minimal arthritis and localized damage
✅ Typically outpatient with shorter recovery than open procedures
2. Derotational Femoral Osteotomy (DFO)
In rare cases where femoral rotation is significantly abnormal (like femoral retroversion), arthroscopy alone isn’t enough.
A DFO realigns the femur by surgically rotating the bone into a more natural position—restoring joint mechanics and reducing impingement.
⚠️ DFO is more invasive than arthroscopy and requires a longer recovery, but it can be life-changing for patients with complex bony alignment problems.
💬 Choosing the Right Treatment
At HipPreservation.org, we take the time to:
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Understand your goals and activity level
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Evaluate the degree of joint damage
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Recommend the least invasive, most effective option to preserve your hip
The goal is not just pain relief—it’s long-term hip preservation.
Comparison of Treatment Options for FAI
Treatment
Non-Surgical Treatment
Hip Arthroscopy
Derotational Femoral Osteotomy (DFO)
What It Does
- Activity modification
- Physical therapy
- Medications or injections
- Aims to relieve pain and inflammation
- Minimally invasive surgery
- Repairs labrum, removes bone spurs
- Improves hip mechanics and relieves pain
- Surgically reorients the femur
- Corrects significant version abnormalities
- Improves hip alignment and function
Recovery Timeline After FAI Treatment
Whether your treatment plan includes physical therapy or surgery, recovery from femoroacetabular impingement (FAI) is a structured process. It’s designed to reduce pain, restore function, and protect your hip from long-term damage.
Recovery looks different depending on the treatment route you and your care team choose:
Non-Surgical Management
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Weeks 1–6: Rest, activity modification, targeted physical therapy
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Focus: Reducing pain and inflammation, restoring basic mobility
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Tools: Anti-inflammatory meds, occasional cortisone or PRP injections
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Return to full activity: Often within 6–12 weeks (with consistent therapy)
✅ Ideal for patients with early-stage impingement or minimal structural damage
Hip Arthroscopy Recovery
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Week 1–2: Crutches with partial weight bearing, pain management
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Week 3–6: Begin formal physical therapy focused on range of motion and stability
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Week 6–12: Strength training and neuromuscular re-education
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Months 3–6: Gradual return to sport or high-level activities
✅ Most patients return to regular activity between 3–6 months, depending on the severity of damage and goals
Derotational Femoral Osteotomy (DFO) Recovery
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Hospital Stay: 2–4 days post-op
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Weeks 1–6: Non-weight bearing or limited weight bearing
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Weeks 6–12: Begin progressive physical therapy after bone healing confirmed
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Months 3–6: Build strength and mobility
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6–12 Months: Full return to activity
✅ DFO recovery is longer, but often the most effective option when rotation abnormalities are a major contributor
Your recovery plan is fully personalized. We’ll walk with you at every step—from your first visit to your return to activity.
Hip Arthroscopy Recovery Milestone Checklist
Use this checklist to track your progress after hip arthroscopy for FAI. Timelines may vary slightly depending on your individual recovery plan.
Outcomes & Long-Term Joint Health After FAI Treatment
With proper diagnosis and timely treatment, most patients with femoroacetabular impingement (FAI) experience excellent long-term outcomes. The key is addressing the underlying mechanical problem before it causes irreversible damage.
At HipPreservation.org, we focus not just on symptom relief—but on protecting your hip from future deterioration so you can stay active, mobile, and pain-free.
Expected Outcomes with Treatment
Whether treated conservatively or surgically, many patients experience:
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Significant reduction in hip pain
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Improved joint stability and movement
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Return to daily activities and recreational sports
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Lower risk of labral re-tears or progressive cartilage damage
Why Early Treatment Matters
If left untreated, chronic impingement can lead to:
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Labral degeneration
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Cartilage loss
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Early-onset arthritis
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Eventual need for total hip replacement
Treating FAI early—before permanent damage occurs—offers the best chance at preserving your natural joint for decades.
Our Goal: Preserve Your Hip, Protect Your Lifestyle
We take pride in helping patients:
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Avoid unnecessary joint replacement
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Delay the progression of arthritis
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Maintain strength, balance, and performance
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Get back to their sport or active lifestyle—stronger than before
💬 “This was the first time a doctor explained why I had pain—and how to actually fix it.” — Real patient, post-arthroscopy
Before surgery, I couldn’t sit through a class, drive more than 20 minutes, or play the sport I loved. After arthroscopy, not only is the pain gone—I’m back on the field and finally feel like myself again.
— Samantha, 22-year-old soccer player with cam-type FAI
Frequently Asked Questions
❓ What is femoroacetabular impingement (FAI)?
FAI is a condition where bone overgrowth on the hip joint—either on the ball (cam) or socket (pincer)—causes abnormal contact during movement. This leads to pain, labral tears, and cartilage damage.
❓ Can FAI be treated without surgery?
Yes. Early-stage FAI or mild symptoms can often be managed with physical therapy, activity modification, and anti-inflammatory treatments. However, these options don’t correct the underlying bone shape.
❓ How do I know if I have FAI or just a labral tear?
A labral tear is often a result of FAI. If you’ve been diagnosed with a tear but haven’t had imaging to check for bone abnormalities, you may not have the full picture. A full evaluation includes X-rays and MRI to assess bone shape and soft tissue.
❓ What happens during hip arthroscopy?
Hip arthroscopy is a minimally invasive surgery where a camera and tools are inserted through small incisions to:
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Repair or remove damaged tissue (like the labrum)
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Reshape the femoral head or acetabulum
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Improve joint motion and reduce pain
❓ What’s the recovery like after surgery?
Most patients walk with crutches for 2–4 weeks and begin physical therapy within days of surgery. Return to activity ranges from 3 to 6 months, depending on severity and goals.
👉 Download the Hip Arthroscopy Pre and Post Operative Instructions
❓ Will this prevent arthritis later on?
FAI surgery can’t reverse existing arthritis, but it can slow or stop further joint damage. The goal is to preserve your natural hip for as long as possible—especially in young or active individuals.
❓ Am I a candidate for hip arthroscopy?
You might be a candidate if:
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You’re under 50 with mechanical hip pain
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You’ve been diagnosed with a labral tear or cam/pincer lesion
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You don’t have advanced arthritis
👉 Take our quick surgical candidacy quiz ›
Take the Next Step Toward Hip Relief
If you’ve been dealing with lingering hip pain, limited mobility, or a diagnosis that doesn’t quite fit—you don’t have to wait or wonder anymore.
Whether you’re an athlete, a weekend warrior, or someone who just wants to walk without pain, we’re here to help you understand what’s going on—and how to fix it.
At HipPreservation.org, we specialize in:
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Accurate diagnosis of femoroacetabular impingement (FAI)
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Personalized treatment plans for active patients
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Preserving your natural hip for as long as possible
Book Your Consultation Today
Ready to take control of your hip health?
Let’s create a plan that works for your goals, your body, and your future.
🤔 Not Sure If You Need Surgery?
Take our quick quiz to see if you’re a candidate for hip arthroscopy or another preservation treatment.
👉 Take the Surgical Candidacy Quiz ›
💬 We’re here to help you move better, live stronger, and feel like yourself again.