Sacroiliac Joint Pain


  • Source of primary low back pain &/or lower extremity pain in approximately 15-30% of patients with low back pain
  • Idiopathic
  • Extra-articular:
    • Enthesis / ligamentous sprain
    • Insufficiency fracture
    • Fracture after major trauma
    • Possible predisposition with ligamentous laxity conditions
  • Intra-articular:
    • Osteoarthritis
    • Infection
      • Usually haematogenous spread & unilateral
      • Occasionally iatrogenic, e.g post injection
      • Pseudomonas aeruginosa, Staphylococcus aureus, Cryptococcus, Mycobacterium tuberculosis
      • Predisposing factors include trauma, endocarditis, IVDU, & immunosuppression
    • Inflammatory arthropathies
      • Ankylosing spondylitis
      • Reiter’s syndrome
      • Psoriatic arthropathy

Sacroiliac Joint Pain 1


    • Metabolic processes
      • CPPD disease
      • Gout
      • Ochronosis
      • Hyperparathyroidism
      • Renal osteodystrophy
      • Acromegaly
    • Tumours
      • GCT
      • Chondrosarcoma
      • Synovial villoadenoma
      • Metastases
    • Instability
      • Iatrogenic (overzealous bone harvesting for grafts or from pelvic resection of tumours)
      • Pregnancy
        • Typically 3rd trimester of pregnancy results in hypermobility of sacroiliac joint because of increased levels of estrogen & relaxin that cause soft tissues supporting joint to loosen – pain can develop earlier in some patients
        • This laxity may predispose sacroiliac joint ligaments to painful sprain
        • Mechanical trauma of childbirth also may cause joint pain
      • Lumbar spine fusion or hip arthrodesis may transfer additional forces to sacroiliac joint, creating cumulative stress and pain (43% of patients develop some level of sacroiliac degeneration within 5 years of lumbar fusion)


Differential Diagnosis

  • Intrinsic disk disease
  • Nerve root compression
  • Zygapophyseal joint pain
  • Primary or secondary myofascial syndromes
  • Non-spinal structures:
    1. Gastrointestinal
    2. Genitourinary
    3. Gynecologic
    4. Hip joint dysfunction


Diagnostic evaluation

  • Pain patterns:
    • Referred pain to an area just inferior to ipsilateral PSIS
  • Physical examination:
    • Used to exclude other diagnostic possibilities
    • A false-positive straight leg raise test may occur when affected leg is elevated to approximately 60° because false dural tension symptoms are caused by sacroiliac joint motion at this degree of elevation
  • Imaging:
    • Plain radiographs
      • AP pelvic & inlet & outlet views, and sacroiliac views +/- lateral sacrum
      • When instability suspected; single leg weight-bearing pelvic (flamingo) views
    • CT, MRI, & bone scan may be done predominantly to exclude other causes of pain rather than to diagnose idiopathic sacroiliac joint pain


  • Diagnostic injections:
    • Fluoroscopically or CT-guided, contrast-enhanced injections
    • Maximum volume that should be injected into sacroiliac joint is 2.5 mL
    • Excessive injectate can leak from anterior capsule onto regional neural structures & limit diagnostic specificity

 Sacroiliac Joint Pain 2

Sacroiliac Joint Pain 3


  • Medications:
    • NSAIDs
    • Non-opiate analgesics
    • Opiates
    • Anti-depressants
    • Adjunctive medication including protease & TNF inhibitors
    • Last 3 in liaison with rheumatologist & pain unit
  • Physical therapy:
    • Education in & training of proper body mechanics & posture are essential, as is aerobic conditioning
    • Flexibility & strength training (hamstrings, gluteus maximus & medius, piriformis, erector spinae, latissimus dorsi, & iliacus muscles)
    • Avoid excessive hip external rotation and “clam” exercises
  • Braces (pelvic belt):
    • May provide some pain relief &/or proprioceptive feedback
    • Rapid weaning avoids psychological dependence & prevents decreased soft-tissue flexibility & potential muscular weakness
  • Injections (corticosteroid):
    • Following minimum 4 weeks of appropriate, directed, noninvasive conservative care
    • If pain substantially inhibits work or progress in physical &/or manual therapy, earlier use of an injection procedure may be diagnostic & may provide therapeutic benefit
  • Prolotherapy Injections:
    • 3 separate image-guided intra-articular (+/- extra-articular) injections of 50% Dextrose, each injection given 3-4 weeks apart
    • Reported to give benefit in 75-80% of patients
    • Less successful if associated with ligamentous laxity syndrome 
  • Radiofrequency neurotomy:
    • Indicated after other, less invasive methods of care have been exhausted & diagnosis is proven for chronic joint pain
    • L5 dorsal ramus, its branches to sacroiliac joint, & lateral branches of S1-S3 dorsal rami
    • More effective for extra-articular than intra-articular joint pain
    • 65% report >50% reduction of pain at 6-month follow-up
  • Arthrodesis:
    • Considered only in patients with joint pain proven by controlled diagnostic anesthetic blocks & without any pain sources in lumbar spine
    • It also should be reserved for those who continue to have disabling symptoms that have not responded to aggressive conservative care, i.e. failed non-operative programme
    • Procedures
      • Anterior approach – Open ilioinguinal exposure with joint debridement, bone graft, and double-plate fixation – best for significant instability +/- ligamentous laxity patients
      • Posterior – Minimally invasive extra-articular approach using DIANA (Distraction Interference Arthrodesis with Neurovascular Anticipation) technique – Should not be used for ligamentous laxity patients
      • Direct Lateral/Transgluteal – Minimally invasive technique using iFuse 3D (better than original iFuse as allows extra bone graft) – Also quicker rehab protocol
      • Stabilisation with transiliosacral screws not recommended except in the acute trauma situation
    • Post-operative care
      • PWB 3-12 weeks, depending on technique
      • Serial Xrays to confirm fixation and progressive union/fusion
      • CT to confirm consolidation in DIANA cases at 3 and 6 months