Hip Impingement Tests

Hip Impingement Tests include anterior impingement sign, posterior impingement sign and gear-stick sign.

See Also: Femoro-acetabular Impingement (FAI)

Anterior Hip Impingement Test

The anterior hip impingement test is a controlled recreation of CAM and PINCER femoro-acetabular impingement (FAI) pain.

The patient is positioned supine on the examination table with the hip flexed to 90°, adducted and internally rotated.

If the patient feels pain or demonstrates apprehension, the test is positive, and this is due to the direct contact of the femoral neck with the acetabular rim or labrum.

The sensitivity and specificity for Anterior Hip Impingement Test was 59% and 100%, respectively.

See Also: FADDIR Test

The anterior impingement test was originally described to detect labral lesions in patients with dysplasia.

Posterior Hip Impingement Test

Posterior Hip Impingement Test is useful to elicit pincer FAI pain.

The patient is positioned supine on the edge of the examination couch. With the hip in extension and knee flexed, the hip is gradually externally rotated. The test is positive if the patient demonstrates apprehension or feels pain as it loads the posterior inferior aspect of the hip.

Gear Stick Sign

The Gear Stick Sign is useful in differentiating trochanteric impingement from other sources of hip pain.

The child is placed in a lateral decubitus position with the symptomatic hip up. The limb is passively abducted in extension at the hip from the adducted position.

The test is considered positive with the reproduction of the patient’s symptoms implicating that hip pain is extra-articular and arises from trochanteric impingement (proximally migrated trochanter like Perthes’ sequelae).

Femoral Acetabular Impingement

Femoral acetabular impingement (FAI) is a common source of hip pain in young and middle-aged athletic individuals.

Resulting from altered morphology of the femoral head and/or acetabulum, FAI creates abnormal stresses on the surrounding soft tissue and bone, resulting in labral tears, chondral degeneration, and, ultimately, OA.

Two types of FAI deformities exist:

1. Cam lesions are located on the femoral head and result from an abnormally shaped femoral head repeatedly contacting the acetabulum and surrounding labrum. Occurring most often in young, athletic males, cam lesions are thought to develop in response to extensive sports participation during the high-growth period of adolescence.
2. Pincer lesions, more common in middle aged, active females, result when the acetabulum is overly covering the femoral head, resulting in compression between the acetabular rim and femoral head-neck function, especially during hip flexion. A combination of pincer and cam lesions may also develop.

References

1. Hananouchi T, Yasui Y, Yamamoto K, Toritsuka Y, Ohzono K. Anterior impingement test for labral lesions has high positive predictive value. Clin Orthop Relat Res. 2012 Dec;470(12):3524-9. doi: 10.1007/s11999-012-2450-0. Epub 2012 Jul 6. PMID: 22767418; PMCID: PMC3492600.
2. Klaue K, Durnin CW, Ganz R. The acetabular rim syndrome: a clinical presentation of dysplasia of the hip. J Bone Joint Surg Br. 1991;73:423–429.
3. Cheatham SW. Extra-articular hip impingement: a narrative review of the literature. J Can Chiropr Assoc. 2016 Mar;60(1):47-56. PMID: 27069266; PMCID: PMC4807686.
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6. Agricola, R, et al: The development of cam-type deformity in adolescent and young male soccer players. Am J Sports Med, 40:1099, 2012.
7. Johnson, AC, Shaman, MA, and Ryan, TG: Femoroacetabular impingement in former high-level youth soccer players. Am J Sports Med, 40:1342, 2012.
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