What are the steps for a physical examination of the hip in a case of bilateral femoral (femur bone) antiversion?

Physical Examination of the Hip in Bilateral Femoral Anteversion

The physical examination for bilateral femoral anteversion should focus on the trochanteric prominence angle test (TPAT) performed with the patient prone, measuring the degree of internal rotation when the greater trochanter is most prominent laterally, though this clinical method has limited accuracy (R²=14%) compared to CT imaging and should be considered a screening tool rather than definitive measurement. 1, 2

Patient Positioning and Initial Assessment

Supine Position

• Place the patient supine on the examination table with legs initially straight and parallel, toes pointing upward 3
• Align the limbs and trunk to the body's midline as closely as possible to establish a neutral reference position 3
• Ensure the pelvis is level and not rotated, as pelvic obliquity can create false impressions of hip deformity 3
• Observe the resting position of both hips, noting if they rest in an internally rotated position (common in femoral anteversion) 3

Gait Analysis

• Observe for in-toeing gait pattern, which is characteristic of increased femoral anteversion 4
• In bilateral cases, look for a waddling gait with lateral swaying of the trunk and increased lumbar lordosis 4
• Note any compensatory movement patterns or limping 3

Specific Examination Techniques for Femoral Anteversion

Trochanteric Prominence Angle Test (TPAT) - Primary Method

• Position the patient prone on the examination table 2
• Flex the knee to 90 degrees 2
• Internally rotate the hip while palpating the greater trochanter 2
• The degree of internal rotation at which the greater trochanter is most prominent laterally represents the clinical measurement of femoral anteversion 2
• Important caveat: This method correlates most closely with intraoperative measurements (within 4 degrees) but has limited correlation with CT scans (R²=14%), and disagreement increases with increasing degrees of anteversion 1, 2

Hip Rotation Arc Midpoint Method - Alternative Approach

• With the patient prone and knee flexed to 90 degrees, measure maximum internal and external rotation of the hip 1
• Calculate the midpoint of the total rotation arc 1
• This method shows better correlation (R²=39%) than TPAT but still has significant limitations and a bias of -10 degrees compared to CT imaging 1

Supine Hip Rotation Assessment

• With the patient supine and hip in neutral position, assess the range of internal and external rotation 5
• In femoral anteversion, internal rotation is typically increased while external rotation is decreased 5
• The correlation between anteversion angle and clinical hip rotation is significant but moderate (r=0.49 for internal rotation) 5

Bilateral Assessment Considerations

• Measure both hips separately and document specific findings for each side 3
• The normal left/right difference in anteversion is mean 3.8 degrees, with upper normal limit of 9.8 degrees 5
• Note whether any deformity is fixed or flexible 3
• Document any compensatory pelvic positioning or leg length discrepancy 3

Additional Hip Examination Components

Range of Motion Testing

• Assess hip abduction and adduction with the patient supine 4
• Evaluate flexion, extension, and rotational movements systematically 6
• Limitation of hip abduction is particularly important in hip pathology 4

Stability Testing (if indicated)

• The Ortolani and Barlow maneuvers are primarily useful in infants under 3 months for developmental dysplasia but have limited utility in older children and adults with femoral anteversion 7, 4
• In patients older than 3 months, limitation of hip abduction becomes more clinically relevant than these maneuvers 7

Critical Clinical Pitfalls

• Do not rely on physical examination alone for definitive measurement - all clinical methods (TPAT, Arc midpoint) should be considered screening techniques rather than definitive measurements, with CT or ultrasound imaging required for surgical planning 1
• Patients may tilt their pelvis to compensate for hip deformity, creating false neutral positioning - stabilize the pelvis during assessment 3
• Method disagreements increase substantially with increasing degrees of bony torsion, particularly for TPAT 1
• Avoid confusing benign hip "clicking" without laxity with true pathology 4
• Do not rely solely on asymmetrical skin folds as they have low specificity 4

Documentation Requirements

• Record specific degrees of internal rotation at maximum trochanteric prominence for each hip 3, 2
• Document total rotation arc and midpoint values 1
• Note any compensatory mechanisms, gait abnormalities, and pelvic positioning 3
• Serial measurements allow tracking of progression, particularly important in growing children 3