Mechanical pain located in gluteal/buttock area may radiate to lateral proximal thigh. The pain is usually focalised by patient to the sacroiliac joint also known as “Fortin’s area” (dark red on figure 1). 2 Patient’s will describe pain with sitting and walking (particularly heel striking), standing from a sitting position and going up and down stairs. These two features (location and aggravating features) help distinguish sacroiliac dysfunction from mechanical low back pain.
Figure 1 – Referral pattern of Sacroiliac pain.
Mechanism of Injury:
May occur secondary to trauma, ligamentous laxity peripartum, in flexibility-dependent sports activities.
Sacroiliitis, sciatica, mechanical low back pain, pilonidal abscess
Absence of swelling or erythema. Gait may be antalgic, may sit leaning more on unaffected side. Often an apparent leg length will be present. If measuring bedside look at post med malleolus and tibial tuberosity as well as ASIS bilaterally. This leg length will often disappear with flexion, abduction and external rotation of a hip, hip adduction versus resistance, or with pelvic manoeuvres (flexion of hip v. resistance, extension of hip v. resistance, hip abduction v. resistance, hip adduction v. resistance). Tenderness is usually present over affected dorsal sacroiliac joint.n (figure 2)
Figure 2 – sacroiliac anatomy and dorsal ligaments
– Patrick’s test (figure 4 test) is positive if pain is felt posteriorly over fortin’s area
– Gaenslen’s, with patient lying supine with unaffected side on table, have affected SI joint on edge of bed, allow for affected leg to hang off bed in hip extension, and ask patient to pull unaffected side into full hip flexion. The examiner the applies anterior to posterior pressure over anterior portion of affected pelvis, essentially driving affected sacroiliac joint into edge of bed. Pain posteriorly indicates a positive test.
– Single leg heel load – Having patient stand on a step, ask them to drop their affected heel onto the floor (with knee extended). If this test reproduces pain in the SI joint it is positive.
– Pelvic compression (side and ant-post)
– Stork testing – assessing for movement at the posterior superior iliac spine in relation to the sacrum at the S2 level, abnormal test would show PSIS moving superiorly with ipsilateral hip flexion.
Consider bloodwork, imaging if inflammatory factors on history, diagnostic imaging-guided injections (dorsal sacroiliac ligaments or intraarticular). Xrays of sacroiliac joints may show some osteoarthritis, osteosclerosis of sacral and iliac surfaces. MRI may demonstrate boney edema in affected side. Bone scan may show increase uptake on affected side. Generally imaging is more useful if there is concern about a differential such as ankylosing spondylyitis, an abscess, or bone pathology.
Conservative approach:Sacroiliac belt, pelvic/hip manoeuvres, physiotherapy, chiropractic manipulations would be first line in conservative management. If pain persists imaging-guided cortisone injections may be considered and or radiofrequency ablation. 1,2
Surgical approach: Surgical management would involve fusion of the sacroiliac joint (options include anterior arthrodesis with a plate, anterior and posterior arthrodesis and bilateral arthrodesis).3
Dr. Neil Dilworth (July 18, 2018)
1. Peebles R1, Jonas CE Sacroiliac Joint Dysfunction in the Athlete: Diagnosis and Management. Curr Sports Med Rep. 2017 Sep/Oct;16(5):336-342. doi: 10.1249/JSR.0000000000000410.
2. Ou-Yang DC1, York PJ1, Kleck CJ1, Patel VV1. Diagnosis and Management of Sacroiliac Joint Dysfunction. J Bone Joint Surg Am. 2017 Dec 6;99(23):2027-2036. doi: 10.2106/JBJS.17.00245.
3. Murakami E1, Kurosawa D1, Aizawa T2. Sacroiliac joint arthrodesis for chronic sacroiliac joint pain: an anterior approach and clinical outcomes with a minimum 5-year follow-up. J Neurosurg Spine. 2018 Jun 22:1-7. doi: 10.3171/2018.1.SPINE17115.