What are the symptoms and treatment options for femoroacetabular impingement (FAI)?

Symptoms and Treatment of Femoroacetabular Impingement Syndrome (FAI)

Femoroacetabular impingement syndrome is primarily characterized by groin pain, limited range of motion, and mechanical symptoms that can be effectively managed with a structured approach beginning with conservative treatment for 3 months before considering surgical options.

Symptoms of FAI Syndrome

FAI syndrome presents with a characteristic pattern of symptoms:

Primary Symptoms

• Groin pain - The most common and primary symptom 1, 2
• Pain may also be felt in the:
  • Back
  • Buttock
  • Thigh 1

Additional Symptoms

• Clicking or catching sensations in the hip 2
• Hip stiffness 2
• Feeling of the hip "giving way" or buckling 2
• Limited range of motion, especially with hip flexion, adduction, and internal rotation 2, 3

Symptom Patterns

• Typically slow-onset, persistent pain 3
• Pain often worsens with:
  • Prolonged sitting
  • Walking
  • Athletic activities requiring hip flexion and rotation 4
  • Squatting movements 4

Diagnostic Approach

Diagnosis requires a combination of symptoms, clinical signs, and imaging findings - never imaging alone 4:

Clinical Examination

• FADIR test (Flexion, Adduction, Internal Rotation) - has good sensitivity but poor specificity 1, 3
  • A negative FADIR test helps rule out hip-related pain 1
• FABER test (Flexion, Abduction, External Rotation) may also be positive 2

Imaging Protocol

1. Initial imaging: AP pelvis and lateral femoral head-neck radiographs 4
2. Advanced imaging when indicated:
   • MRI without contrast for labral tears and chondral damage 4
   • CT for 3D morphological assessment when needed 4
   • MR arthrography may be useful when impingement is suspected 4

Classification of FAI

FAI is classified into three types based on morphology:

• Cam impingement: Aspheric femoral head with bony excrescences, common in young males 3, 5
• Pincer impingement: Excessive acetabular coverage 5
• Mixed impingement: Combination of both cam and pincer features 3

Treatment Algorithm

Step 1: Conservative Management (First-Line Treatment)

A structured 3-month conservative approach should be implemented before considering surgery 4:

• Activity modification:

  • Pacing strategies
  • Avoiding activities that exacerbate symptoms
  • Using appropriate footwear 4

• Physical therapy program:

  • Minimum 6-12 weeks
  • At least 3 sessions per week (30+ minutes each)
  • Focus on:
    • Core strengthening
    • Hip girdle muscle strengthening
    • Range of motion exercises
    • Aerobic activity 4
  • Individualized exercise progression every 1-2 weeks 4

• Pain management:

  • Paracetamol (up to 4g/day) as first-line analgesic
  • NSAIDs at lowest effective dose if paracetamol is inadequate 4
  • Consider image-guided intra-articular injections for diagnostic and therapeutic purposes 4, 2

Step 2: Surgical Management (If Conservative Treatment Fails)

Consider surgery after 3 months of failed appropriate conservative management 4:

• Hip arthroscopy is the preferred surgical approach for patients meeting these criteria 4, 6:

  • Age <50 years
  • Minimal or no osteoarthritis
  • No inflammatory arthritis

• Surgical procedures include:

  • Correction of bony abnormalities (cam/pincer lesions)
  • Labral repair (superior to debridement for long-term outcomes)
  • Addressing cartilage damage 4, 2, 6

• For larger cartilage defects:

  • Microfracture for focal lesions <4 cm²
  • Mosaicplasty for focal lesions <3 cm² in patients <45 years
  • Osteochondral Allograft Transplantation for defects >2.5 cm² 4

• Total hip arthroplasty for severe cases with significant joint destruction 4

Follow-up and Evaluation

• Assess treatment response after 3 months of conservative management 4
• Regular follow-up (at least annually) to monitor:
  • Symptom progression
  • Development of early osteoarthritis
  • Functional status 4

Important Considerations

• FAI is a common cause of hip pain in young and active individuals 6
• Without proper treatment, FAI can lead to progressive joint damage and early osteoarthritis 2, 3
• Conservative treatment success rate: approximately 53-78% return to play in athletes 4
• Incidental intra-articular findings are common in asymptomatic individuals - diagnosis should never be made on imaging alone 1, 4
• Extraarticular impingement has recently gained importance in understanding FAI 7