1. Cover slide

2. Pubic Symphysis and Sacroiliac Joint Professor Emeritus Moira O’Brien
MOB TCD
Pubic Symphysis and
Sacroiliac Joint
Professor Emeritus Moira O’Brien
FRCPI, FFSEM, FFSEM (UK), FTCD
Trinity College
Dublin

3. Pubic Symphysis Secondary cartilagenous joint
MOB TCD
Secondary cartilagenous joint
Articular surface of medial aspect of body of pubis
Covered with hyaline articular cartilage
Disc of fibrocartilage in between

4. Pubic Symphysis
MOB TCD
A cavity may develop in the disc, but it is not lined with synovial membrane
The arcuate or inferior ligament is stronger than the superior pubic ligament

5. Secondary Changes in Symphysis
MOB TCD
There is normally very little movement at the pubic symphysis, except during the latter months of pregnancy
Infection, e.g. Reiter’s syndrome
Loss of hip mobility, especially internal rotation
Fricker, 1997

6. Sacroiliac Joint Modified synovial plane joint
MOB TCD
Modified synovial plane joint
The auricular articular surfaces of the sacrum and the Ilium
The hyaline cartilage on the articular surfaces is rough
The capsule is attached just beyond the articular margin
The interosseous sacroiliac ligament is one of the strongest ligaments in the body and is posterior to the joint
This articulation is almost immobile

7. Sacroiliac Joint Accessory Ligaments
MOB TCD
Sacrotuberous ligaments
Sacrospinous ligaments
Iliolumbar ligaments
Posterior superior iliac spine is middle of the joint posteriorly, it is superficial
During gait, the amount of accessory movement at the sacroiliac joint helps to protect the lumbar intervertebral discs

8. Sacroiliac Joint
MOB TCD
Decreasing the torsional stresses associated with pelvic rotation
Movement at the sacroiliac joint also helps to decrease forward shearing at the L5/S1 junction during the hip extension phase of gait
More movement during pregnancy
Tigney & Lindsay et al., quoted in DeMann, 1997

9. Sacroiliac Joint
MOB TCD
Secondary changes may arise in the joint due to anatomical malalignments and biomechanical factors
Leg length discrepancies
Poor running technique
The arms swing across the front of the body, causing stress at the joint

10. “BMJ Publishing Group Limited (“BMJ Group”) 2012. All rights reserved
Copyright slide