Diagnosis

Femoroacetabular Impingement (FAI) is a disorder of the hip joint, and as such can affect both males and females. At The Hip and Groin Clinic there is a ratio of about 5:1 (male: female) attending the clinic and subsequently requiring surgical management of symptoms.

The overwhelming majority of cases affected with FAI are young, active, athletic individuals from a sporting background.

75% of males are younger than 35 years of age
– mainly high impact sports such as gaelic football, hurling, soccer and rugby.

60% of females are older than 35 years
– mainly recreational sports such as running and gym/fitness

In Ireland, the majority of competitive athletes play Gaelic games such as football and hurling.

Symptoms typically experienced by many of the athletes with evidence of FAI-related pathology are progressive stiffness and inflexibility around their hips.

This stiffness can often be present for a number of days following training or playing a match and in many cases is associated with progressive groin pain, lower back discomfort and pain in the buttock.

Hamstring tightness and recurrent hamstring injuries can also be associated with underlying hip pathology.

WARNING SIGNS:

  • Pain & Stiffness during & after activity
  • Limping after activity
  • Hamstring tightness

The development of symptoms associated with FAI is insidious, often progressing for many years undiagnosed.

The overwhelming majority of athletes attending the clinic describe the onset of their symptoms as “gradual”, in many cases presenting to the clinic only when they are forced to withdraw from their sports.

Early diagnosis and appropriate management is critical.

Generally symptoms greater than 2 years often result in poorer outcomes post-operatively. Often at this stage irreparable damage has occurred including signs of early onset osteoarthritis.

CLINICAL EXAMINATION

By assessing how the hip moves, and through performing highly sensitive impingement provocation tests allows for the detection of and location of possible symptoms such as pain and stiffness.

In addition to examining the contralateral side, there are ‘normal population’ values for the hip joint that should be kept in mind.

FADIR – This is the most sensitive physical examination for FAI. With the patient supine, the examiner raises one leg with the hip Flexed to 90o and knee flexed to 90o. The hip is then Adducted and Internally Rotated.

This test is positive if it produced pain and is highly indicative of FAI, labral tear or hip chondral lesion or loose bodies.

FABER – With the patient in the supine position, Flexion is applied to the hip, followed by ABduction and External Rotation

This test is used to identify the presence of intra-articular hip disorders such as FAI, labral tears, chondral lesions and osteoarthritis with the reproduction of groin pain and/or posterior hip pain on external rotation

Clinical examination of 1500 athletes attending our clinic shows that the FADIR test was positive in 70% of cases and FABER test in 48% of cases.

By examining range of movement, athletes with symptomatic FAI will typically reveal significant loss of hip movements on one of both sides.

Stretching and excessive ROM of the hip joint to improve stiffness is counterproductive and can increase the impingement.

Flexion

Normal Mean: 123o (± 9)

Patient Pre-op Mean: 112o (± 12)

Abduction

Normal mean: 46o (± 10)

Patient Pre-op Mean: 44o (± 9)

Adduction

Normal Mean: unavailable

Patient Pre-op Mean: 20o (± 9)

Internal Rotation

Normal Mean: 34o (± 9)

Patient Pre-op Mean: 24o ± (11.5)

External Rotation

Normal Mean: 33o (SD 8)

Patient Pre-op Mean: 37o (SD 9) 

A reduction in ROM is typically seen among athletes with FAI, resulting in progressive stiffness and associated pain on certain movements.

3 in 4 cases have limitation of flexion and/or internal rotation

X-rays

X-rays of the pelvis and hip joints are essential for all patients suspected of having hip impingement; the presence of a CAM or Pincer deformity can easily be noted, if present; the shape and orientation of the socket can be measured. An Antero-posterior (AP) view of the pelvis, false profile Dunn view images are required

CAM Impingement

A CAM deformity results from the development of a bony prominence (bump) on the femoral head (ball); with repetitive flexion of the hip i.e. striking a ball, jumping, squatting, etc. the CAM lesion rubs against the underside of the edge of the acetabulum (socket) resulting in abrasive damage to the labrum (seal of the hip).

The loss of the integrity of the labrum is the first step in progressive damage to the hip joint

60% of our athletes have evidence of CAM deformity when measured on X-ray image.

Pincer Impingement

Pincer impingement is characterized by acetabular over-coverage of the femoral head. The pincer deformity forces the labrum against the femoral head resulting in abrasive damage leading to a labral tear or detachment. The shape of the acetabulum (socket) may predispose patients to developing a Pincer deformity such as an abnormally deep socket or a socket with poor orientation.

49% of our athletes have clear evidence of an abnormality of the rim of the socket (acetabulum).

MR Arthrography

MR Arthrogram is considered the ‘gold standard’ diagnostic tool for imaging labral tears and articular cartilage lesions associated with impingement.

Labral tears can occur acutely as a result of trauma or over a long period of time due to repetitive micro-trauma associated with FAI or instability of the hip joint

Damage to the articular cartilage is caused by repetitive trauma and osteoarthritis, accelerated by the presence of structural deformities associated with FAI

Osteoarthritis

Many sportsmen attend the clinic too late for repair surgery

Irreversible damage to the cartilage has resulted from playing for many years through stiffness and pain.

In almost every case, athletes have been treated by numerous rehabilitation programs, steroid injections, rest periods but eventual all are forced out of their sports

This 33-year old senior hurler attended the clinic following years of progressive hip and groin stiffness. He had no significant pain.

He required a Total Hip Replacement (THR) as repair surgery was not possible because of the degree of hip arthritis present.