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Femoroacetabular impingement syndrome

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Added 2023 ACR, 2023 APTA, 2021 AAFP, and 2016 WA-FAI guidelines for the diagnosis and management of femoroacetabular impingement syndrome.



FAIS is a motion-related clinical disorder of the hip with a triad of symptoms, clinical signs, and imaging findings. It represents symptomatic premature contact between the proximal femur and the acetabulum.
The pathophysiology of FAIS involves abnormal contact between the femoral head and the acetabulum due to bony abnormalities. This can lead to shearing forces at the acetabular labrum and cartilage during physiological hip motion, potentially causing cartilage wear and eventual OA.
The epidemiology of FAIS remains largely unknown. Imaging findings suggestive of the syndrome are also prevalent in asymptomatic individuals, with a higher prevalence observed in athletes.
Disease course
Clinically, patients with FAIS often present with motion- or position-related pain in the hip or groin. Pain may also be felt in the back, buttock, or thigh. They may also describe clicking, catching, locking, stiffness, limited ROM (typically restricted internal rotation in flexion), or giving way. In addition to these symptoms, patients with FAIS may demonstrate altered gait mechanics and hip joint loading.
Prognosis and risk of recurrence
The prognosis of FAIS can vary widely and is influenced by factors such as the type of FAIS (cam, pincer, or mixed), the extent of cartilage and labral damage, and the timing and type of intervention. Treatment often leads to symptom improvement, allowing patients to resume full activity, including sports. Without treatment, symptoms of FAIS typically worsen over time. Cam morphology is associated with the development of hip OA.


Key sources

The following summarized guidelines for the evaluation and management of femoroacetabular impingement syndrome are prepared by our editorial team based on guidelines from the American College of Radiology (ACR 2023), the American Physical Therapy Association (APTA 2023), the American Academy of Family Physicians (AAFP 2021), and the Warwick Agreement on Femoroacetabular Impingement Syndrome (WA-FAI 2016). ...
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Screening and diagnosis

As per WA-FAI 2016 guidelines:
Use the following terminology:
cam morphology
pincer morphology
Avoid using the following terminology
asymptomatic femoroacetabular impingement
symptomatic femoroacetabular impingement
femoroacetabular impingement morphology
deformity, abnormality, or lesion when referring to cam or pincer morphology
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  • Diagnosis

Diagnostic investigations

History and physical examination: as per APTA 2023 guidelines, consider obtaining the FADIR and FABER tests to exclude femoroacetabular impingement in case of negative results.
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  • Diagnostic imaging

Nonpharmacologic interventions

Lifestyle modifications: as per APTA 2023 guidelines, consider providing patient education and counseling for modifying aggravating factors and managing pain associated with non-arthritic hip joint pain related to FAIS.

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  • Movement pattern training

  • Physical therapy

  • Manual therapy

  • Bracing

Surgical interventions

Indications for surgery: as per WA-FAI 2016 guidelines, consider offering open or arthroscopic surgery to improve the hip morphology and repair damaged tissue.

Preventative measures

Primary prevention: as per WA-FAI 2016 guidelines, insufficient evidence regarding which individuals with cam or pincer morphologies will develop FAIS syndrome. Recognize that preventive measures May have a role in high-risk populations, but it is rarely indicated to offer surgery to these individuals.