Sacroiliac pain, the great masquerade

Sacroiliac joint pain, the great masquerader

By Dr Brian Lee, Pain Specialist, Nedlands

Back pain affects up to 80% of Australians at some point in their lifetime. A commonly overlooked cause of this is sacroiliac joint pain, which some estimate to be involved in 15-30% of back pain presentation. The sacroiliac joint (SIJ) connects the sacrum to the pelvic girdle. It is a strong, ligamentous joint supported by musculature, and primarily functions to absorb shock between the upper body and the pelvis/legs and allows for very little motion. Issues may arise when the SIJ is too lax and allows too much movement, is fixed and moves little, or is inflamed (sacroiliitis) due to degeneration (compounded by joint laxity), infection or autoimmune conditions.

Sacroiliac joint pain can be a great masquerader, often mimicking symptoms felt with other causes of back pain: • Dull, aching lumbar axial pain, typically radiating to the buttock, is similar to that of facetogenic axial pain. It can accompany lumbosacral stiffness and reduced range of motion, particularly flexion. • Sharp pain radiating to the buttocks/posterior thigh, and rarely extend beyond the knee down into ankle, is similar to radicular pain. This commonly continued from Page 34 trialled after other therapies, such as cannabinoids, have been tried. The non-psychoactive cannabinoid, cannabidiol (CBD) alone has shown promise as an anti-inflammatory and anxiolytic. It is a safe non-intoxicant and in many jurisdictions is available over the counter. However, a UK review of over the counter CBD found that 40% contained no cannabinoids at all, 20% contained Key messages

SIJ pain may account for up to 30% of low back pain Diagnosis can be challenging Treatment is multidisciplinary.

occurs on weightbearing on affected side and worsens with climbing stairs or stepping on an uneven ground. While SIJ pain can be seen in patients of all ages and gender, there are risk factors. • Pregnancy and childbirth with progesterone-induced ligament laxity and hypermobility and associated weight gain. which may persist well after childbirth and cause ongoing pain • Gait instability (e.g. leg length discrepancy or scoliosis) causing uneven pressure on one side of the pelvis, accelerating degeneration • Previous spinal surgery, especially in the cases of lumbar fusion. In general, due to inherent immobility in fused sections of vertebrae, degeneration will be accelerated in neighboring facet joints or SIJ • Repetitive stress, including heavy lifting and laborious work. Diagnosis of SIJ pain can be THC which is illegal, and 20% contained inactive cannabinoids. Fortunately, in Australia, prescribed CBD products are only available by authority and are produced with certification of Good Manufacturing Practice. For musculoskeletal pain, CBD has been shown to have antiinflammatory effects in rheumatic pain in animal models. Medicinal cannabis is well-tolerated with fewer harms than with opiates challenging. Patients tend to report their pain as being ‘below the beltline’ and unilateral rather than central. A common description is a localised ache on one side of the sacrum that radiates to the ipsilateral buttock and posterior thigh. Examination may reveal a focal tenderness and reproducible pain on the PSIS, which directly overlies the SIJ. A positive response to a SIJ injection of local anaesthetic greatly increases diagnostic accuracy. Treatment for SIJ pain is multidisciplinary, involving extensive physiotherapy input to strengthen the supporting musculature, stretching and relieving associated muscle tension, and potential use of a pelvic brace. Judicious use of non-opioid analgesia will aid in rehabilitation. A pain specialist can aid with procedural relief, including both SIJ injections and radiofrequency ablation (rhizotomy) of lateral branches of sacral nerves that innervate the joint. Patients with severe laxity may find prolotherapy helpful in strengthening the ligamentous structure. A subset of patients may require a surgical fixation in treatment-resistant cases.

Medicinal cannabis in managing musculoskeletal pain

Author competing interests – nil and has demonstrated efficacy for pain reduction and opioid sparing. Dosing and ratios of THC and CBD need to be managed and monitored slowly and carefully to optimise outcomes and to reduce adverse effects in addition to managing patients with complex multi-morbidity.

– References available on request Author competing interests – the author is medical director of Emerald Clinics