What is the attachment site for ligaments that stabilize the sacroiliac (SI) joints?

What is the attachment site for ligaments that stabilize the sacroiliac (SI) joints?

• A. Sacral tuberosity
• B. Median sacral crest
• C. Transverse processes
• D. Sacral promontory

Answer: (A)

Stability of the sacroiliac joints comes largely from the interosseous sacroiliac ligaments, which connect the sacrum to the ilium. They run from the sacral tuberosity to the iliac tuberosity, anchoring the pelvis and resisting movement, especially under weight-bearing forces. That sacral tuberosity is the key attachment site for these ligaments, providing strong posterior stability to the SI joints. The other bony features—median sacral crest, transverse processes, and sacral promontory—are landmarks or surfaces, not the primary attachment points for these stabilizing ligaments.

Stability of the sacroiliac joints comes largely from the interosseous sacroiliac ligaments, which connect the sacrum to the ilium. They run from the sacral tuberosity to the iliac tuberosity, anchoring the pelvis and resisting movement, especially under weight-bearing forces. That sacral tuberosity is the key attachment site for these ligaments, providing strong posterior stability to the SI joints. The other bony features—median sacral crest, transverse processes, and sacral promontory—are landmarks or surfaces, not the primary attachment points for these stabilizing ligaments.