Interosseous sacro-iliac ligament

Looks like

Short, very strong fibres filling the rough gap between sacrum and ilium behind the sacroiliac joint.

What it does

The main bond of the joint, carrying the weight of the upper body from the spine to the pelvis.

Keeping it well

Rarely torn except in high-energy trauma. Inflammation nearby (sacroiliitis) shows on MRI in axial spondyloarthritis.

Related conditions

• Axial spondyloarthritis
• Bone metastases and spinal cord compression
• Brucellosis
• Developmental dysplasia of the hip
• Gout
• Haemophilia & bleeding disorders
• Lyme disease
• Marfan syndrome & connective tissue disorders
• Obstructed labour and obstetric fistula
• Osteoarthritis
• Psoriatic arthritis
• Reactive arthritis
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder