Keywords:
Infection, Athletic injuries, Acute, Normal variants, Plain radiographic studies, Bones, Anatomy
Authors:
S. Alwan, B. Sharif, M. Paliwalla; Harrow/UK
DOI:
10.1594/essr2018/P-0096
Background
The pelvis consists of three paired bones: the ilium,
ischium and pubis and the sacrum.
The primary ossification centres for the ilium ossify at 12 weeks gestational age,
and for the ischium,
pubis,
this occurs at 18 and 20 weeks gestational age respectively. The sacrum is formed of five segments,
ossification occurs in a craniocaudal direction from 14 weeks gestational age.
Continued osteogenesis and skeletal growth occurs at secondary ossification centres in the pelvis and proximal femur,
these include the:
- Iliac crest
- Anterior superior iliac spine (ASIS)
- Anterior inferior iliac spine (AIIS)
- Posterior superior iliac spine (PSIS)
- Pubic symphysis
- Ischial tuberosity
- Femoral head
- Greater trochanter
- Lesser trochanter
These secondary ossification centres go through different stages of predictable pattern of growth and development until complete fusion is achieved.
Female ossification centres devlop 1-2 years ahead of males. Table 1 and Table 2.
The radiographic appearances during this time can vary from child to child and can be mistaken for pathology.
Fig. 1: AP radiograph of the pelvis of a child aged 20 months.
Fig. 2: AP radiograph of a the pelvis of a 4 year old child.
Fig. 3: AP radiograph of the pelvis of a child aged 9 years.
Fig. 4: AP radiograph of the pelvis of a 15 year old adolescent.