Craig's Test

Original Editor - Manisha Shrestha
Top Contributors - Manisha Shrestha, Kim Jackson and Stacy Schiurring

Purpose

Craig's test is a passive test that is used to measure femoral anteversion or forward torsion of the femoral neck. It is also known as 'Trochanteric Prominence Angle Test (TPAT)'.

Femoral anteversion is the angle between the femoral neck and femoral shaft, indicating the degree of torsion of the femur. It is also known as Femoral neck anteversion.

There are various ways via which femoral anteversion can be measured. These are some methods used: imaging using radiography, fluoroscopy, computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI) as well as functional assessments. MRI method has been shown to be more reliable (r = 0.97) than CT (r = 0.77) and any other tests. Craig's test is the most commonly used physical examination test for femoral anteversion.

Technique

Craig's Test

Patient position

The patient was placed in the prone position with hip in neutral and the knee flexion of 90° of tested side on an examination table.

Therapist position

The examiner stood on the contralateral side to the subject’s hip being examined. While stabilizing the sacrum with the forearm, the greater trochanter was palpated with the hand that was more cranial.

Procedure

Examiner with caudal hand then palpated the greater trochanter of the tested side while passively internally rotating the hip until the most prominent portion of the greater trochanter reached its most lateral position.

One examiner hold the position of leg in the position where greater trochanter is the most prominent. Another examiner measures the angle between the shaft of the tibia (a line bisecting the medial and lateral malleoli) and a line perpendicular to the table (an imaginary vertical line extending from the table) using either goniometer or inclinometer. And thus records the angle of femoral anteversion.

Interpretation

1. Normal: At birth, the mean anteversion angle is 30 degrees which decreases to 8-15 degrees in adults (angle of internal rotation).
2. Angle >15 degrees: Increased anteversion leads to squinting patellae & pigeon toed walking (in-toeing) which is twice as common in girls.
3. Angle <8 degrees: Retroversion

Evidence

Pyschometric Properties

1. A study published in 2015 used three different methods to measure the femoral anteversion during Craig’s test: a goniometer, a goniometer with a laser beam, and an inclinometer, and measured inter and intra- reliability of these three methods. This study showed the intra-examiner reliability for both examiners with all three measurement methods, with scores of 0.82, 0.86, and 0.73 for examiner 1 and 0.74, 0.78, and 0.72 for examiner 2 for the goniometer, goniometer with the laser beam, and inclinometer, respectively. Whereas, the inter-examiner reliability was below moderate for both the goniometer (0.25) and inclinometer (0.27) and moderate for the goniometer with the laser beam (0.62). Thus it suggests the use of a goniometer with a laser beam while measuring Craig's test.
2. Another study published in 2020, compared Craig’s test and computed tomography (CT) in measuring the femoral anteversion angle(FAA) in patients with anterior cruciate ligament (ACL) injuries. No significant correlation of the FAA was found between Craig’s test and CT measurements on both the involved (r=0.12, p=0.59) and uninvolved sides (r=0.04, p=0.84).
3. In study, 2009 compared magnetic resonance imaging (MRI) and Craig's test in measuring FAA in 18 healthy adults. It showed intra-class correlation (ICC) values representing intratester reliability for examiners 1 and 2 were 0.88 and 0.90, with standard error of measurement (SEM) values of 3.2° and 3.1°, respectively. The ICC value representing intertester reliability was 0.83, with a SEM of 3.8°.

Clinical Significance

1. FAA affects the biomechanics of the hip, as moment arms and the line of action of muscles around the joint are altered. It affects the position of the trochanter and therefore the line of action of the muscles surrounding that region.
   • A higher FAA results in a slightly shorter hip extension moment arm and an increase in hip flexion moment arm of the abductor muscles. Furthermore, high FAA results in a shorter abductor lever arm and also considerably increases internal rotation moment length.
   • Reduced FAA results in higher shear forces on the femoral neck‐head junction, quantifiable as a 42% increase with an FNA of 0° and 86% with an FNA of −12.5° and 12.5°, respectively.
   • Distally, increased FNA is associated with a progressive increase in patellofemoral contact pressures.
2. Increased FAA may lead pelvic instability during gait and in‐toeing gait which is often accompanied by the compensatory external rotation of the tibia.
3. Greater FAA is also associated with a number of orthopaedic pathologies, including increased risk of anterior cruciate ligament injury, lower hip abductor and vastus medialis activity, impaired tracking of the patella, femoral trochlear dysplasia, unilateral hip osteoarthritis, and femoral acetabular impingement.
4. Reduced FAA is associated with slipped capital femoral epiphysis.
5. Excessive anteversion is twice as common in girls as in boys.
6. Not only is increased or decreased FAA a risk factor for clinical conditions, but asymmetries in FAA also appear to influence musculoskeletal health.

Resources

add any relevant resources here

References

Original Editor - Manisha Shrestha Top Contributors - Manisha Shrestha, Kim Jackson and Stacy Schiurring