MSK

Anteversion

Normal Anteversion of the Femoral Neck (radiography)1,2

Normal Femoral Neck Torsion Angle (Computed Tomography)3

(see reference for method)

References:

1. Vanderwilde R, Staheli LT, Chew DE, Malagon V: Measurements on radiographs of the foot in normal infants and children. J Bone Joint Surg 70A:407, 1988. Modified by from Ozonoff MB.

2. Pediatric Orthopedic Radiology. W.B. Saunders Company: Philadelphia. 1992. (Used with permission from M.B. Ozonoff; publisher's permission requested)

Hip

Normal Acetabular Angles*1

AP Radiograph of Pelvis

*Acetabular angle defined as the angle made from line through the Y synchondroses and another line through the superior and inferior points of the iliac portion of the acetabulum.

Reference:

1. Caffey in Ozonoff MB. Pediatric Orthopedic Radiology. W.B. Saunders Company: Philadelphia. 1992. p181. (Used with permission from M.B. Ozonoff; publisher's permission requested)

Normal Sonographic Appearance of Infant Hip

*The alpha angle is the geometric complement of the acetabular angle, derived from a line drawn along the lateral bony margin of the ilium and from a line drawn across the bony acetabular roof.

Reference:

1. Modified from Graf R, Schuler P. in Sonography of the infant hip: an atlas. Weinheim: VCH Verlagsgesellschaft, 1986 and Schlesinger AE, Hernandez RJ. Diseases of the musculoskeletal system in children: imaging with CT, sonography, and MR. AJR 1992; 158: 729-741.

Jump back to Acetabular Angle

Medial Joint Space

The medial joint space is used to determine lateral displacement of the femoral head. It is defined as the distance measured from the medial edge of the femoral ossific nucleus (where it is broadest just above the growth plate) to the adjacent acetabular wall. When the ossific nucleus is absent or asymmetric, measurement is made from the femoral neck metaphysis just below the growth plate. This measurement is best made on the frog-lateral projection.

Normal range: 6 months to 11 years = 5-12 mm. From side to side, the medial joint space of both hips should be within 1.5 mm of each other.

AP radiograph of pelvis

Medial joint space = distance from widest portion of femoral head to adjacent acetabulum

Reference:

1. Eyring et al., 1965 in reference: Ozonoff MB. Pediatric Orthopedic Radiology. W.B. Saunders Company: Philadelphia. 1992. p181. (Used with permission from M.B. Ozonoff; publisher's permission requested)

Center-Edge Angle (Wiberg)

The center edge angle is used to evaluate the relationship of the femoral head to the acetabulum. It is defined as the angle formed by a line drawn through the center of the femoral head and the edge of the acetabulum and another line perpendicular to a line drawn through the center of the femoral heads. The value of this is limited if the femoral head is deformed or if the ossific center is small or eccentric.

AP radiograph of pelvis highlighting the center-edge angle

Normal center-Edge Angles

Reference:

1. Ozonoff MB. Pediatric Orthopedic Radiology. W.B. Saunders Company: Philadelphia. 1992. p181. (Used with permission from M.B. Ozonoff; publisher's permission requested)

Kyphosis and Lordosis

Standing Lateral Radiograph Normal Angles for

Thoracic Kyphosis and Lumbar Lordosis

Thoracic Kyphosis

Normal Angle - 21° to 33º

measured from T3 to T12

Thoracic kyphosis is usually measured using the superior end plate of T3 and the inferior end plate of T12.

Lumbar Lordosis

Normal Angle 31 to 50º

measured from L1 to L5

Lumbar lordosis is measured using the superior end plate of L1 and the inferior end plate of L5

1. Reference:

2. Ozonoff MB. Pediatric Orthopedic Radiology. W.B. Saunders Company: Philadelphia. 1992. p. 68.

Metaphyseal- Diaphyseal Angle

Measurement of the Metaphyseal- Diaphyseal Angle for Differentiation between Physiologic Bowing and Tibia Vara