Sacroiliac Joint Pain

The Sacroiliac joint lies between the sacrum and the ilium bones of the pelvis and is a potential pain driver in patients with axial lower back pain and buttock pain. It is often underdiagnosed and can be pathoanatomical in up to 30% of chronic lower back pain sufferers. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment – PubMed.

Aetiological causes include degenerative, inflammatory, traumatic, following recent spinal surgery and rarely infectious Sacroiliac Joint Pain – StatPearls – NCBI Bookshelf. The vast majority of sacroiliac joint disorder affect the older patient population due to degeneration; however, younger patients are not exempt and symptoms can manifest following sporting injuries or pregnancy due to hormonal changes increasing joint mobility. Sacroiliac Joint and Pelvic Dysfunction Due to Symphysiolysis in Postpartum Women – PMC and is a common site for inflammatory back pain related to spondyloarthropathies Seronegative Spondyloarthropathy – StatPearls – NCBI Bookshelf

What are the signs and symptoms?

For patients with sacroiliac joint pain, they typically complain of deep-seated lower back and buttock symptoms. Patients can sometimes localise very specifically their symptoms inferior and medial to the PSIS (exact location of the SIJ) and when present, it can be helpful diagnostically and is termed the Fortin finger test. The Fortin finger test: an indicator of sacroiliac pain – PubMed. Localised pain is not always reliable, however, as referral symptoms from the sacroiliac joint can be extensive. Diagnosing Sacroiliac Joint Pain – PubMed

There is more commonly an inciting event in patients with sacroiliac joint pain when compared to facet or discogenic causes. Falls, motor vehicle collisions, repetitive stress from sporting activities, especially those requiring excessive rotational movements, and pregnancy are often described Inciting events initiating injection-proven sacroiliac joint syndrome – PubMed .

How is it diagnosed?

Diagnosing the sacroiliac joint as a cause of a patient’s lower back pain is often challenging. There are clear similarities in its presentation when compared to more common causes of axial back lower pain, such as discogenic or facet.

As described previously, localised SIJ pain, inferior and medial to the SIJ, is helpful but not diagnostic. Diagnosing Sacroiliac Joint Pain – PubMed. Clinically and with plain radiographs, the hip should be cleared as a potential cause of posterior hip/buttock pain. Neurologically, the patient should be intact; if there are any progressive leg symptoms, especially in a dermatomal distribution, an alternative diagnosis should be considered.

There are some clinical tests that have been suggested to stress the SIJ, but their sensitivity and specificity it attributing pain to the Sacroiliac joint remains poor Diagnostic Accuracy of Clusters of Pain Provocation Tests for Detecting Sacroiliac Joint Pain: Systematic Review With Meta-analysis – PubMed. Imaging can often add little to the diagnosis. MRI can be helpful in sacroiliitis that can be clearly seen on STIR sequences and are highly suggestive of spondyloarthropathy. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment – PubMed. Then it can also be helpful at excluding other potential diagnoses, including sacral insufficiency fractures/lesions and benign and aggressive bone lesions in the pelvis. X-rays are usually underwhelming and may show some degeneration in the sacroiliac joint, which is a common finding in the asymptomatic population. The prevalence of sacroiliac joint degeneration in asymptomatic adults – PubMed. Although no true ‘gold standard’ diagnostic test exists. An image-guided injection of local anaesthetic +/- steroid into the sacroiliac joint can be helpful in confirming the sacroiliac joint as a cause of pain. Use of Diagnostic Injections to Evaluate Sacroiliac Joint Pain – PMC

How is it treated?

For the mainstay of isolated lower back pain, there are no surgical indications. (Excluding traumatic causes due to spinal instability, malignancies or infectious causes).

Period of relative rest. For acute episodes of SIJ/pain buttock pain (without red flag symptoms/non-inflammatory), the vast majority will self-resolve within 12 weeks without any medical input. Sacroiliac Joint Pain – StatPearls – NCBI Bookshelf
For patients with inflammatory back pain (under the age of 40, worse at rest, better with movement, early morning stiffness lasting longer than 30 minutes, with or without underlying psoriasis or inflammatory bowel disease) with confirmed sacroiliitis on MRI, these patients will be referred to rheumatology for review and treatment. Ankylosing Spondylitis – StatPearls – NCBI Bookshelf
Physiotherapy and exercise. This can be helpful for both mechanical and inflammatory causes. The best exercises are the ones the patient will be compliant with. Evidence does not support one specific rehab/exercise programme over another. Effectiveness of exercise intervention in relieving symptoms of ankylosing spondylitis: A network meta-analysis – PubMed
An image-guided injection of local anaesthetic and steroid can be both diagnostic and therapeutic for patients with refractory symptoms that have not improved with initial conservative options. Stratification of Sacroiliac Joint Pain Patients and the Efficacy of Ultrasound-Guided Injection Treatment: A Retrospective Study – PMC

Surgical management

Surgery for Sacroiliac joint pain is rarely indicated, but if a patient experiences severe symptoms (that are non-inflammatory in nature) that have failed conservative management but had an initial response to an image-guided Sacroiliac joint injection, arthrodesis (fusion) may be considered. Minimally Invasive Posterior SI Joint Fusion with a Novel Cortical Allograft: Real-World, Long-Term, Outcomes from a Large, Multisite US Cohort – PMC. Unfortunately even with fusion refractory symptoms of varying degree are still common. Surgical Outcomes of Patients with Sacroiliac Joint Pain: An Analysis of Patients with Poor Results Regarding Activities of Daily Living – PMC