Sacral Insufficiency Fracture?
Written by Chris Heywood - MSc BSc (Hons) MCSP HCPC reg
Physiotherapist
Sacral insufficiency fractures (SIFs) are a common yet often unrecognized cause of debilitating back pain, especially in the elderly. Although not exclusive to this age group, they predominantly affect older adults. Let’s explore what causes these fractures and what symptoms might indicate you have one.
SIFs were first described by Lourie in 1982, but even today, they are frequently underdiagnosed or diagnosed late. This is partly because the symptoms are often vague and can mimic other more common conditions, leading healthcare professionals to overlook them.
​​Several factors can predispose individuals to SIFs:
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Elderly Women With Osteoporosis :- Osteoporosis weakens bones, making them more susceptible to fractures from minor falls or injuries. Up to half of women and 20% of men over 50 who suffer fractures do so due to reduced bone strength. For more info
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Previous Pelvic Radiation :- Radiation therapy, often used in cancer treatment, can degrade bone quality in the treated area. This risk is especially notable for cancers of the bladder, rectum, prostate, cervix, womb, and vagina. For more info
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Multiple Myeloma :- Multiple Myeloma is a type of cancer that affects the white blood cells, more specifically a plasma cell, that is found inside our bone marrow. White blood cells normally help to neutralise pathogens such as bacteria and viruses by producing antibodies. Abnormal plasma cells can go on to form masses within bone, such as the pelvis altering the strength and quality and subsequent risk of fracture. For more info
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Paget's Disease :- Paget's Disease is a condition that effects the normal ''repair and renewal' process that we see in healthy bone metabolism. Bones are under a constant cycle whereby old bone is broken down, removed, and replaced by new bone. In Paget's disease the balance of this process is altered, leading to an increased volume of overall bone turnover that can make new bone weak and and brittle. For more info
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Renal Osteodystrophy :- Renal Osteodystrophy is a type of bone disease that is caused by having a long term, elevated level of Parathyroid Hormone in your blood stream. This can cause an increased level of calcium to be removed from your bones making the natural reparative cycle of bone increasingly inefficient. It is normally associate with chronic kidney disease. For more info
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Steroid Induced Osteopenia :- Steroid Induced Osteopenia refers to the thinning of the bones that we can occur in people who are on long term steroids. This can include inhalers, prescribed for some breathing complaints, and tablets such as Prednisolone, with the general definition of long-term being everyday for more than 3 months. Steroid creams may carry less of a risk. For more info
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Hyperparathyroidism :- Parathyroid Hormone has a direct effect on the levels of calcium, phosphorus and vitamin D in our blood and bones. It is produced by 4 Parathyroid Glands that are found behind the Thyroid Gland in the neck. HYPER-Parathyroidism refers to when elevated levels of the hormone are produced which can in turn lead to Chronic Kidney Disease and Renal Osteodystrophy, as above. For more info
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Rheumatoid Arthritis :- Rheumatoid Arthritis (RA) is an autoimmune disorder that commonly causes joint inflammation. The process that underlies the condition can also affect the bone matrix - the architectural makeup of the bone itself, which can lead to bone weakness and poor. For more info
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What is a Sacral Insufficiency Fracture (SIF)?
Sacral insufficiency fractures are a sub-type of stress fracture that are normally the result of normal stresses being applied to 'abnormal' bone, that has lost its elastic resistance (2).
Denis et al (3), divided the sacrum up into three separate zones:
1) Outer Sacrum - Zone 1
2) Mid Sacrum - Zone 2
3) Inner Sacrum - Zone 3
The lower lumbar spine above, joining to the sacrum below
Sacroplasty
Sacroplasty is a procedure where a special cement PMMA (Polymethyl Methacrylate) is injected under image guidance, into the sacral fracture site(s). It is a fairly new technique that has been derived from a more longstanding procedure called Kyphoplasty, which involves injecting the PMMA in to a vertebral body in the spine instead
There are two main techniques:
1) The Posterior Approach
2) The Long-Axis Approach
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More recently there has been an introduction of a Sacral Kyphoplasty but this is significantly less common than the aforementioned techniques so will not be discussed further at present.
As with many new medical procedures the problem of good, strong evidence is limited and only time will solve this however the research that has been undertaken to date is very positive on the whole. Akin to spinal disc prolapses, there is an acceptance that spontaneous recovery will, in most, occur naturally in 12 months (on average), so conservative management is championed by many. For those that don't heal however, are in too much pain, or where the conservative management (which is structured around significantly reduced mobility) is not ideal, Sacroplasty may be an option.
Sacroplasty has very limited patient based education available which is why this initial page has been created. If you do want further reading however the two papers listed below offer excellent insight and can be accessed by Google with no fee or memberships required. They both use medical terminology which may be difficult for some to understand however as more information and pictures become available we will endeavour to feature this in an easy to understand format.
The following paper's were very helpful in the construction of this page so are acknowledged:
Lyders EM, Whitlow CT, Baker MD, Morris PP. Imaging and Treatment of Sacral Insufficiency Fractures. Am J Neuroradiol 2010;31:201-10 (excellent for reading around the subject and getting a global overview)
Health Net National Medical Policy: Percutaneous Sacroplasty. (Very good review paper of present research and outcomes)
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References:
(1) Lourie H. Spontaneous osteoporotic fracture of the sacrum: an unrecognised syndrome in the elderly. JAMA 1982;248:715-17
(2) Lyders EM, Whitlow CT, Baker MD, Morris PP. Imaging and Treatment of Sacral Insufficiency Fractures. Am J Neuroradiol 2010;31:201-10
(3) Denis F, Davis S, Comfort T. Sacral fractures: an important problem. Clin Orthop Relat Res 1988;227:67-81
(4) De Smet AA, Neff JR. Pubic and sacral insufficiency fractures: clinical course and radiologic findings. AJR Am J Roentgenol 1985; 145:601-06