Proximal focal femoral deficiency - type B Aitken classification

Case contributed by Dr Mahmoud Ibrahim Mekhaimar


Lower limb length discrepancy.

Patient Data

Age: 5 years
Gender: Female

Multislice CT scan of both hips with multiplanar reconstruction revealed:

  • comminution of the left femoral neck
  • the left femoral shaft is seen displaced upward and laterally
  • a relatively smaller size left capital femoral epiphysis as compared to the contralateral aspect
  • mildly hypoplastic left iliac plate with relatively flattened iliac fossa
  • reduced length and abnormal rotation of the left femoral shaft. Mild sclerosis of the upper aspect of the left femoral shaft is seen as well
  • a horizontal radio-lucent fracture line is seen traversing the subtrochanteric region of the left femur
  • reduced girth of the muscle groups around the left hip joint and the proximal thigh, likely representing disuse atrophy
  • normal osseous features of the right femoral epiphyses
  • preserved hip joints spaces
  • no evidence of joint effusion or intra-articular loose bodies
  • the muscle groups around the right hip are normal in appearance with preserved intermuscular fat planes

The above-described features are suggestive of proximal focal femoral deficiency (type B Aitken's classification), for clinical correlation. 

Special thanks to Dr Ahmed Abdel Karim, MD. Lecturer of Diagnostic and Interventional Radiology, Cairo University Hospitals.

Case Discussion

Proximal femoral focal deficiency is a congenital partial absence of the proximal end of the femur with subsequent shortening of the entire lower limb. The etiology is unknown in most of the cases. 

Different methods of classifications have been proposed. The Aitken classification is based on the radiographic depends upon the radiologic appearance of the acetabulum, femoral head, femoral shaft, and the attachment between the femoral head and the femoral shaft at maturity. There are four types (A-D).

Type B, as in our case, can be characterized by:

  • the acetabulum is more or less normal in appearance or moderately dysplastic but contains the femoral head
  • no osseous connection is formed between the femoral head and the shaft at maturity
  • short femur
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Case information

rID: 70439
Published: 19th Aug 2019
Last edited: 21st Aug 2019
Inclusion in quiz mode: Included

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