Sacroiliac joint dysfunction may cause sciatica-like symptoms that rarely extend below the knee. Stiffness and reduced range of motion in the lower back, hips, pelvis, and groin, which may cause difficulty with movements such as walking up stairs or bending at the waist. This type of joint has free nerve endings that can cause chronic pain if the joint degenerates or does not move properly. Sacroiliac joint pain ranges from mild to severe depending on the extent and cause of injury.
Pathophysiology
- Mechanism often involves a combination of twisting/rotation and axial loading
- Between 40 and 50% of patients with injection-confirmed SIJ pain can identify a specific precipitating event
- Most frequently cited include motor vehicle collisions, falls, repetitive stress, and pregnancy
- Pathologic changes can be broken down into intra-articular and extra-articular
- Intra-articular: capsular or synovial disruption, capsular and ligamentous tension, abnormal joint mechanics, microfractures or macro fractures, chondromalacia,
- Extra-articular: hypomobility or hypermobility, extraneous compression or shearing forces soft tissue injury, and inflammation
- There is a paucity of literature on SIJ pain in athletes
- Asymmetric loading is likely a risk factor including kicking, swinging, throwing and single leg stance
Etiology
- Osteoarthritis
- Spondyloarthropathies
Pathoanatomy
- Sacroiliac Joint
- Articulation of Sacrum and Ilium
- Diarthrodial Joint with fibrous capsule and synovial fluid
- Function: support the upper body, dampen the impact of ambulation
- Intrinsic
- Length discrepancies
- Scoliosis
- Hypermobility
- Extrinsic
- Gait or biomechanical dysfunction
- Biomechanical abnormalities
- Spondyloarthropathies
- Ankylosing Spondylitis
- Other
- Persistent or prolonged microtrauma or repetitive exercise (e.g., running)
- Pregnancy
- History of spine surgery
- Sports
- Football
- Basketball
- Powerlifting
- Gymnastics
- Golf
- Cross country skiing
- Rowing
- Use of elliptical, stair stepper
Differential Diagnosis
- Fractures
- Compression Fracture
- Burst Fracture
- Chance Fracture
- Spinous Process Fracture
- Transverse Process Fracture
- Rib Fracture
- Sacral Stress Fracture
- Neurological
- Lumbar Radiculopathy
- Cauda Equina Syndrome
- Sciatica
- Musculoskeletal
- Mechanical Back Pain
- Scoliosis
- Kyphosis
- Herniated Disc
- Facet Joint Pain
- Sacroilliac Joint Pain
- Spinal Stenosis
- Spondylolysis
- Spondylolisthesis
- Hyperlordosis
- Baastrups Disease
- Autoimmune
- Ankylosing Spondylitis
- Infectious
- Spinal Epidural Abscess
- Osteomyelitis
- Pediatric
- Scheuermann’s Disease
Symptoms
- History
- Pain patterns are highly variable, which makes clinical diagnosis challenging
- Although it can be traumatic, generally insidious from overuse
- Some patients endorse buttock pain extending into the posterolateral thigh[13]
- Slipman et al found patients reported buttock pain (94%), lumbar pain (72%), radiating into the lower extremity (50%), pain below the knee (28%), and groin pain (14%)
- Worse with running, climbing stairs, standing from a seated position
- Physical Exam: Physical Exam Back
- May be tender over sacral sulcus
- Special Tests
- FABER Test: Patient is supine, the affected limb is placed in the figure 4 position (flexion, abduction, external rotation)
- Posterior Shear Test: Patient supine, stabilize SI joint, hip and knee flexed to 90° and posterior load applied
- Resisted Abduction Test: Patient supine, leg abducted about 30°, knee slightly flexed, asked to abduct against resistance
- Standing Flexion Test: Patient standing and flexes forward while examiner palpates PSIS and also on the S2 spinous process
- Stork Test: Patient stands on one leg while flexing the ipsilateral hip to 90° while examiner palpates PSIS and sacrum
- One-Legged Hyperextension: Patient patient hyperextends backward, the examiner may help stabilize the patient
- Sacroiliac Compression Test: Lateral decubitus on the affected side, apply compression of SI joint
- Sacroiliac Distraction Test: Supine patient, apply force at bilateral ASIS
- Gaenslens Test: Supine, flex contralateral leg to the chest, hang ipsilateral leg off the examination table
- Fortins Sign: Patient points to pain source with one finger, localizes to PSIS
- Cranial Shear Test: Patient prone, apply cranial directed force to the sacrum
- Sacral Thrust Test: patient prone, apply anteriorly directed force to the sacrum
- Active Straight Leg Raise Test: Patient holds straight leg a few inches off the examination table
Diagnostic Injection
- Diagnostic gold standard
- History, exam, and imaging are generally not enough to make a diagnosis of SI joint pain
- Diagnostic confidence is 90%[14]
- Some variability to ‘positive’ test
- Most commonly accepted is at least 75% reduction if symptoms with injection[15]
- If less than 50%, consider other etiologies
- Reported success rates based on approach
- Landmark based approach: 12% – 22%[16]
- Ultrasound: 40% to 90%[17]
- Fluoroscopy: 97% to 98%<
- CT: 100%[18]
- Injectant is typically anesthetic plus/minus corticosteroids
Radiographs
- Standard Radiographs Pelvis
- Of limited utility do to overlying osseous structures
MRI
- Sensitivity >90%[19]
- Indicated if the inflammatory condition is suspected
- Not useful in identifying non-inflammatory conditions
CT
- Elgafy et al: Using injection confirmed SI Joint Pain[20]
- Sensitivity 57.5%
- Specificity 69%
Radionuclide Imaging
- Sensitivity 13% – 46.1%[21]
- Specificity 89.5% – 100%
Treatment
Prognosis
- Most cases of SI joint pain have a favorable prognosis.
Nonoperative
- Medications
- Topical and oral NSAIDS
- Acetaminophen
- Activity Modification
- Physical Therapy
- Up to 95% of patients improve with PT[22]
- Spinal Manipulation Therapy
- Includes manual therapy, osteopathic manual treatment, chiropractic adjustments
- Well designed studies fail to show benefits
- Needs to be updated
- Prolotherapy
- Kim et al: Significant difference in symptoms at 15 minutes in prolotherapy arm vs steroid arm (control)
- Corticosteroid Injections
- Extra-articular (EA): Appear to be superior to placebo
- Intra-articular (IA): Appear to be superior to placebo
- EA injections may be superior to IA according to Murakami et al
- Neurolysis
- The best candidates are those that have obtained relief from SI joint blocks
- Techniques include heat (conventional radiofrequency), bipolar, cold (cryoneurolysis), chemical (alcohol/phenol), pulsed, combined
- Conventional RF: No controlled studies were published, two retrospective reviews show mixed results
- Consider Orthosis
- Shoe inserts for pes planus or pes cavus
- Heel Lift for leg length discrepancy
- Sacroiliac Brace if dysfunction is due to hypermobility
Operative
- Indications unclear
- Refractory to conservative measures? At least 6 months
- Must have had a positive diagnostic injection
- In the setting of trauma
- Technique
- Open SIJ Fusion
- Minimally invasive SIJ Fusion
