Cam lesion: Definition, Uses, and Clinical Overview

Cam lesion Introduction (What it is)

A Cam lesion is an extra bony prominence at the junction of the femoral head and femoral neck.
It is commonly discussed in relation to femoroacetabular impingement (FAI), a cause of hip pain and limited motion.
The term is used in orthopedics, sports medicine, and physical therapy to describe a hip shape that can pinch the joint.
It may be found on imaging even when a person has no symptoms.

Why Cam lesion used (Purpose / benefits)

“Cam lesion” is not a device or treatment; it is a clinical term that helps clinicians describe a specific hip morphology (shape). Its main purpose is to identify a common structural contributor to hip impingement and related symptoms.

In a typical hip, the femoral head is close to spherical and glides smoothly within the acetabulum (hip socket). With a Cam lesion, the head–neck junction is less round. During hip flexion and rotation—movements used in sitting, squatting, pivoting, and many sports—the irregular contour can abut the rim of the socket. This contact can increase stress on joint structures.

Using the term provides a shared framework for:

• Explaining symptoms such as groin pain, catching, or reduced range of motion in a way that connects anatomy to mechanics.
• Guiding evaluation by prompting targeted physical exam maneuvers and appropriate imaging choices.
• Planning management, which may include activity modification strategies, physical therapy approaches, injections for diagnostic clarification in some settings, or surgery in selected cases.
• Discussing joint preservation, because repeated impingement is one pathway that may contribute to labral injury and cartilage damage over time (the pace and clinical significance vary by clinician and case).

Indications (When orthopedic clinicians use it)

Orthopedic and sports medicine clinicians commonly consider and document a Cam lesion in scenarios such as:

• Hip or groin pain that is worse with flexion-based activities (sitting low, squats, climbing, pivoting)
• Mechanical symptoms (clicking, catching, a sense of “pinching”) that raise concern for labral involvement
• Reduced hip internal rotation or painful range of motion on exam
• Suspected femoroacetabular impingement (FAI), particularly in active individuals
• Imaging performed for hip pain that suggests abnormal head–neck contour (often assessed on X-ray and/or MRI)
• Preoperative planning for hip arthroscopy when femoral osteoplasty (reshaping) is being considered
• Evaluation of hip shape after certain childhood/adolescent hip conditions (for example, deformity patterns following slipped capital femoral epiphysis), as clinically relevant

Contraindications / when it’s NOT ideal

Because a Cam lesion is a descriptive diagnosis rather than a treatment, “contraindications” most often apply to interventions aimed at correcting or treating symptoms associated with it, especially surgery.

Situations where aggressive intervention may be less suitable, or where another approach may be emphasized, can include:

• Advanced hip osteoarthritis on imaging, where joint degeneration may be a dominant driver of symptoms and reshaping procedures may offer less predictable benefit (varies by clinician and case)
• Pain patterns not consistent with intra-articular hip pathology, such as symptoms more suggestive of lumbar spine, pelvic, abdominal, or extra-articular causes
• Incidental Cam lesion without symptoms, since a structural finding alone does not always explain pain or require treatment
• Medical or anesthetic risk factors that make elective surgery higher risk, prompting consideration of nonoperative strategies (varies by individual health status)
• Hip conditions where anatomy or stability is the primary issue, such as certain dysplasia patterns; management priorities can differ and may focus on socket coverage or stability rather than femoral reshaping (decision-making varies by clinician and case)
• Severe motion limitation from non-FAI causes (for example, stiffness dominated by arthritis), where treating impingement morphology may not address the main limitation

How it works (Mechanism / physiology)

A Cam lesion affects hip function through biomechanics, not medication-like “onset” or “duration.” There is no pharmacologic action and no reversible “wearing off.” Instead, it is a structural contour that can change how the joint contacts under load.

Biomechanical principle

In femoroacetabular impingement, abnormal contact occurs between the femur and acetabulum during certain movements. With Cam morphology, the femoral head–neck junction is less concave than expected. When the hip flexes and rotates, that prominence can engage the acetabular rim sooner and with higher local stress than a smoothly contoured femur.

Relevant hip anatomy and tissues

Key structures discussed alongside a Cam lesion include:

• Femoral head and neck: the ball and the narrowed segment supporting it; the Cam lesion sits at their junction.
• Acetabulum: the socket portion of the pelvis that receives the femoral head.
• Labrum: a fibrocartilaginous rim that deepens the socket and contributes to stability and sealing of the joint.
• Articular cartilage: the smooth joint surface lining the femoral head and acetabulum.
• Hip capsule and surrounding muscles: structures that influence stability, motion, and load distribution.

What gets stressed and why it matters

When a Cam lesion impinges, clinicians often focus on potential consequences such as:

• Labral strain or tearing, especially in areas where the femur abuts the socket rim.
• Cartilage injury on the acetabular side due to shear forces as the less-spherical femoral head rotates and “pushes” into the socket margin.
• Motion restriction, particularly decreased internal rotation in flexion, which may be seen on exam.

Not every person with Cam morphology develops symptoms or tissue injury. Symptom development depends on factors such as activity demands, hip anatomy as a whole (including socket shape), soft tissue capacity, and coexisting conditions—varies by clinician and case.

Cam lesion Procedure overview (How it’s applied)

A Cam lesion is typically identified and managed through a staged clinical workflow rather than “applied” like a device. A general overview is:

1. Evaluation / exam
   Clinicians take a history focused on pain location (often groin/anterior hip), activity triggers, mechanical symptoms, and functional limits. A physical exam assesses hip range of motion, strength, gait, and provocative maneuvers commonly used when FAI is suspected.

2. Preparation (clinical decision-making)
   The clinician considers other causes of hip-region pain (lumbar spine, hernia-related pain, tendon conditions, stress injury, inflammatory causes). The goal is to determine whether symptoms appear intra-articular (from within the joint) and whether imaging is appropriate.

3. Testing / imaging
   – X-rays are commonly used to evaluate bony shape and joint space. Measurements such as the alpha angle may be discussed to quantify Cam morphology (measurement thresholds and interpretation vary by clinician and case).
   – MRI or MR arthrogram may be used to evaluate labrum and cartilage and to look for associated injuries.
   – CT may be considered in some settings for detailed bony anatomy and surgical planning (use varies by clinician and case).

4. Intervention options (selected based on findings and goals)
   – Nonoperative management may include education, activity modification concepts, and physical therapy focusing on hip mechanics, strength, and movement strategies.
   – Injections may be used in some practices to help clarify whether pain is coming from the joint versus other sources; therapeutic intent varies by clinician and case.
   – Surgery (often hip arthroscopy) may be considered for persistent symptoms with supportive exam and imaging. A common surgical concept is femoral osteoplasty, reshaping the head–neck junction to reduce impingement, sometimes combined with labral repair or cartilage procedures as appropriate.

5. Immediate checks and follow-up
   Follow-up typically includes reassessment of symptoms and function, monitoring for complications if an intervention was performed, and progression of rehabilitation milestones when relevant.

This overview is informational; specific evaluation and treatment pathways vary by clinician and case.

Types / variations

Cam-related discussions often include variations in morphology, clinical presentation, and associated patterns:

• Cam vs pincer vs mixed FAI
• Cam morphology emphasizes the femoral head–neck prominence.
• Pincer morphology emphasizes socket-side overcoverage or rim prominence.

• Mixed indicates features of both, which is commonly described in practice.

• Size, location, and extent of the lesion
  The prominence may be more anterior, anterosuperior, or extend over a broader arc of the head–neck junction. Location can matter because impingement is position-dependent.

• Symptomatic vs asymptomatic Cam lesion
  Some people have Cam morphology on imaging without pain or limitation. Others have clear activity-related symptoms and exam findings consistent with impingement.

• Primary vs secondary Cam morphology
  Cam shape may be described as developing during growth in some individuals, while in other cases it may be associated with prior hip disorders or altered development (for example, deformity patterns after slipped capital femoral epiphysis). Classification and causation discussions vary by clinician and case.

• Imaging characterization differences
  Cam lesions can be described using radiographic views and measurements (such as alpha angle), MRI appearance, and 3D assessment when CT is used. Exact measurement cutoffs and their clinical significance can vary by clinician and case.

Pros and cons

Pros:

• Provides a clear, widely used term to describe a common hip shape linked to FAI
• Helps connect symptoms and motion limits to hip biomechanics in patient-friendly explanations
• Supports structured evaluation with targeted exam and imaging considerations
• Can guide surgical planning when hip preservation procedures are being considered
• Encourages consideration of associated labral and cartilage pathology when relevant

Cons:

• A Cam lesion can be present on imaging without causing symptoms, which can complicate interpretation
• The term may be over-attributed as the sole cause of pain when other diagnoses coexist
• Imaging measurements and thresholds are not interpreted identically across all clinicians
• Management decisions depend on multiple factors beyond morphology (cartilage status, stability, goals), so the finding alone does not dictate next steps
• Discussions can unintentionally imply inevitability of arthritis, which is not uniform and varies by clinician and case

Aftercare & longevity

Because a Cam lesion is a structural finding, “longevity” depends on the context:

• If managed nonoperatively, outcomes often relate to symptom control and function. Factors that may influence how someone does over time include activity demands, hip strength and mobility, movement patterns, body weight, and coexisting spine or pelvic conditions. Follow-up needs vary by clinician and case.

• If treated surgically (for example, arthroscopic femoral osteoplasty), recovery and longer-term results are influenced by the degree of preexisting cartilage damage, whether labral repair was needed, adherence to the rehabilitation plan, and safe progression back to sport or work demands. Weight-bearing status and motion precautions are procedure-specific and surgeon-specific.

Across approaches, clinicians commonly monitor:

• Symptom trends (pain location, mechanical symptoms, tolerance of sitting and sport)
• Functional measures (walking tolerance, stairs, squatting tolerance)
• Hip range of motion and strength balance
• Signs of progressive joint degeneration on imaging when clinically indicated

No single timeline fits everyone; recovery and durability vary by clinician and case.

Alternatives / comparisons

Management related to a Cam lesion is often compared across a spectrum from monitoring to surgery. High-level comparisons include:

• Observation / monitoring
  Appropriate in some cases when Cam morphology is found incidentally or symptoms are mild. The emphasis is typically on correlating imaging with symptoms rather than treating the image.

• Physical therapy and activity modification concepts vs procedures
  Rehabilitation-based care focuses on improving hip and trunk strength, movement coordination, and tolerance of daily and sport tasks. It does not change bone shape, but it may help reduce symptom provocation for some people. Response varies by clinician and case.

• Medications vs structural management
  Anti-inflammatory medicines may reduce pain and inflammation symptoms in some settings, but they do not address the bony morphology. Medication use is individualized and depends on risks and comorbidities (discussion varies by clinician and case).

• Injection-based approaches
  Intra-articular injections are sometimes used to support diagnosis (confirming the joint as a pain generator) and/or provide temporary symptom reduction. Duration and degree of relief can vary widely.

• Hip arthroscopy vs open procedures
  Arthroscopy is commonly discussed for femoral osteoplasty and labral work in appropriately selected patients. Open approaches may be considered in more complex anatomy or revision settings; choice depends on anatomy, surgeon experience, and case complexity.

• Joint preservation vs joint replacement
  In the presence of substantial arthritis, clinicians may discuss whether hip preservation procedures are likely to help versus focusing on arthritis-oriented management, which can include arthroplasty in selected cases. The decision is highly individualized.

Cam lesion Common questions (FAQ)

Q: Is a Cam lesion the same thing as femoroacetabular impingement (FAI)?
A Cam lesion is one type of bony shape change that can contribute to FAI. FAI is the broader clinical concept describing abnormal contact in the hip that may cause symptoms and tissue stress. People can have Cam morphology without symptomatic FAI.

Q: Where does Cam lesion pain usually show up?
When symptoms are related to intra-articular hip pathology, pain is often described in the groin or front of the hip, sometimes with a “pinching” sensation during flexion. Some people report lateral hip pain or pain that seems to radiate, which can overlap with other conditions. Location alone is not diagnostic.

Q: Can a Cam lesion be seen on X-ray, or do you need an MRI?
Cam morphology is often evaluated on X-ray using specific views that show the femoral head–neck contour. MRI is commonly used when clinicians need more information about the labrum, cartilage, and other soft tissues. The imaging choice depends on symptoms, exam findings, and local practice patterns.

Q: If I have a Cam lesion on imaging, does that mean I need surgery?
Not necessarily. Imaging findings are interpreted alongside symptoms, physical exam, functional limitation, and joint health (including cartilage status). Many care plans begin with nonoperative options, and surgery is generally considered only in selected cases—varies by clinician and case.

Q: How long do results last if a Cam lesion is surgically reshaped?
Surgical reshaping aims to reduce impingement by improving the head–neck contour. Longevity depends on multiple factors, including preexisting cartilage damage, adherence to rehabilitation, return-to-sport demands, and the presence of other hip anatomy issues. Outcomes and durability vary by clinician and case.

Q: Is treatment for Cam lesion considered safe?
All medical treatments carry potential risks and benefits. Nonoperative care has different risk profiles than injections or surgery, and surgical risks depend on the procedure and patient factors. Safety discussions are individualized and vary by clinician and case.

Q: What does recovery look like after hip arthroscopy for Cam morphology?
Recovery typically involves a structured rehabilitation period to restore motion, strength, and function. Weight-bearing status, use of braces, and progression timelines vary by surgeon and the procedures performed (for example, whether labral repair was done). Many people return to normal activities gradually rather than immediately.

Q: Can I drive or work if I have a Cam lesion?
Many people can continue driving and working depending on pain, mobility, and job demands. After procedures or if pain is significant, temporary limitations may be discussed, particularly for safety-sensitive tasks. Recommendations vary by clinician and case.

Q: How much does evaluation or treatment for a Cam lesion cost?
Costs vary widely by region, facility type, insurance coverage, imaging choices, and whether treatment involves therapy, injections, or surgery. Out-of-pocket expenses can differ substantially even for the same general pathway. A clinic or insurer can usually provide a case-specific estimate.

Q: Does a Cam lesion always lead to arthritis?
A Cam lesion is one factor that may increase joint stress in certain motion patterns, but progression to arthritis is not inevitable and is not the same for everyone. Risk depends on multiple variables, including activity demands, coexisting hip morphology, and the degree of cartilage injury. Long-term outlook varies by clinician and case.