Pelvic insufficiency fractures (PIFs)

A pelvic insufficiency fracture means a bone in the pelvis has fractured because it is weak or thin. This can happen after radiotherapy to the pelvic area.

What are pelvic insufficiency fractures (PIFs)?

Changes to the bone after radiotherapy can mean the pelvis cannot cope with the normal stresses put on it. This may increase the risk of small cracks or fractures. Doctors call these pelvic insufficiency fractures (PIFs). PIFs are most likely to happen in the first 2 years after pelvic radiotherapy.

Where is the pelvic bone?

The pelvis is the lower part of the tummy (abdomen) between the hips. The bones in this area are called the pelvic bones.

Radiotherapy and PIFs

Radiotherapy may cause changes to the bone in the area being treated. It is most likely to happen when radiotherapy is given to the pelvic area (pelvic radiation). This treatment may be used to treat cancer of the womb, cervix, prostate, bladder, anus or rectum.

Some of the risk factors of PIF include:

  • age
  • gender
  • menopause.

You are more likely to have a PIF after pelvic radiotherapy if you have these risk factors: 

  • you are over the age of 50
  • you are postmenopausal
  • you have a higher risk of osteoporosis.

Looking after your bones can help to reduce your risk.

Symptoms of PIFs

PIFs do not always cause noticeable symptoms. They may show up on a scan that is done for another reason.

Pelvic fracture symptoms can range from a mild ache to severe pain. There may be pain in the lower back or pelvis when moving. This can make walking difficult. Pain is not usually a problem when resting or sleeping.

If you have pain in a bone, always tell your doctor. They can arrange follow-up tests to find out what is causing it and give you treatment if needed.

About our information


  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

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