si joint dysfunction

1. Sacroiliac Joint Dysfunction
Dr Bharat Timilsina
Spine fellow
1st year

2. • Sacroiliac Joint Dysfunction is a degenerative
condition of the sacroiliac joint resulting in
lower back pain
• Hidden cause of low back pain

3. Goals
• EPIDEMIOLOGY
• ETIOLOGY
• ANATOMY
• CLINICAL PRESENTATION
• DIAGNOSTIC MODALITY
• TREATMENT

4. EPIDEMIOLOGY
• Incidence : - up to 15% to 30% of cases of lower
back pain in the outpatient setting
• Risk factors
o previous lumbar spine fusion
o especially when there is >3 levels involved
o considered analogous to adjacent segment disease
o pregnancy and vaginal delivery
o previous trauma to the pelvis
o prior iliac crest bone graft harvesting

5. ETIOLOGY
Pathophysiology:-
1) idiopathic :- the most common
• believed to be a result of repetitive trauma to the SI joint
– can begin insidiously or acutely
• pain is hypothesized to be generated from
» ligamentous/capsule tension
» extraneous compression or shear forces
» hypomobility or hypermobility
» increased levels of estrogen or relaxin during third trimester
of pregnancy leading to hypermobility of the SI joint
» aberrant joint mechanics
» myofascial or kinetic chain imbalances
» inflammation

6. Pathophysiology contd:
• intra-articular mechanisms
– arthritis
• inflammation and degeneration of the SI joint
• occurs in nearly 100% of patients with
spondyloarthropathies
o ankyklosing spondylitis
o Reiter's syndrome
– results in subchondral sclerosis, subchondral cyts,
osteohytes, joint space narrowing, intra-articular
gas and ankylosis

7. intra-articular mechanisms
2) Infection
– usually the result of hematogenous spread
– typically unilateral involvement
– organisms:
– Staphylococcus aureus
– Pseudomonas aeruginosa
– Cryptococcus organisms
– Mycobacterium tuberculosis
– predisposing factors:
– immunosuppression
– endocarditis
– IV drug abuse

8. Pathophysiology:-
intra-articular mechanisms
3) Metabolic
– leads to early degeneration of the joint
– diseases:
• calcium pyrophosphate crystal deposition(cppd- abnormal
deposit of cppd crystal in cartilage assoicated with
hyperparathyridism/hypophospatimia/hypothyroidsm
• gout
• Ochronosis ( Alkaptonuria –rare genetic dis. Homogenestic
oxidase is difficient –blue black discoloration of skin an
cartilage
• hyperparathyroidism
• renal osteodystrophy (metabolic bone disease-seen in CRF)
• acromegaly

9. Pathophysiology:-
intra-articular mechanisms
• Tumors
– primary
• very rare for SI joint
• most common types:
– giant cell tumor
– synovial villoadenomas
– chondrosarcomas
– secondary (metastatic)
• most common
• pelvis accounts for 40% of all oseous metastasis (2nd to
spine)

10. Pathophysiology:
extra-articular mechanisms
• ethesopathy
– inflammation of the ligamentous attachements to the
SI joint
– frequently occurs with spondyloarthropathies
– more frequently the posterior ligaments
• insufficency fractures
– osteoporotic fractures in elderly patients
– repetitive trauma in athletes and military recruits
• post-traumatic
– more common after lateral compression pelvic ring
injuries

11. ANATOMY
• Osteology
– articulation of the ilium and the sacrum
• largest axial joint in the body
– considered synovial even though the superior 75% is
not synovial
– joint surface area of 17.5 cm^2
– articular surface changes with age
• flat until puberty
• by age 30 ridges form on the the iliac articular surface
• synovial surface begins to erode by age 50
• ankylosis is common in men by age 50

12. Muscles
• gluteus maximus
– has fibrous extensions that attach to the anterior and posterior
joint capsule has attachments into the sacrotuberous ligament
– Origin:- Ilium,scrum & coccyx
– Insertion :- Iliotibial tract and GT
• gluteus medius :- O:-gluteal surface of ilium I:- lat. Aspect of GT
• erector spinae:- O:- Lumabr and Lower thoracic region I:- upper
thoracic and cervical region
• latissimus dorsi:- O:- spinous process of T7-12, Thoraco Lumbar
fascia , iliac crest,inf. 3-4 ribs inf angle of scapula I:- floor of
intertubercular grove of humerus
• biceps femoris:- O:- Iscial tuberosity & short head from linea
aspara of femur : Insertion:- lat. Head of fibula
– has attachments to the sacrotuberous ligament
• oblique and transverse abdominus:- O:- costal margin,TL fascia,
iliac crest and inguinal ligament Insertion:- linea alba, pubic
symphysis & xyphoid process

13. Ligament
• anterior joint capsule and ligaments
– are relatively thin
• posterior interosseous ligament
– forms the posterior border of the joint capsule
– there is usually a rudimentary or absent posterior joint
capsule
• sacrotuberous ligament
– attaches from the anterior sacrum and SI joint to the
ishcial tuberosity
• sacrospinous ligament
– attaches from the anterior sacrum and SI joint to the
ischial spine

14. Innervation
• anterior innervation
– L2-S2 ventral rami and sacral plexus
• posterior innervation
– L4-S4 dorsal rami
– Predominiently innervated by post. Rami of S1-2
& occ S3 lateral branch & associated dorsal
ligament
– but rarely by S4 root

15. Biomechanics
• SI joint functions as a triplanar shock absorber
– dissipates loads of the upper trunk and faciliates parturition
– can withstand a medial directed load six times greater than
the lumbar spine
– fails in 1/20th the axial load of the lumbar spine
– sacral compression with weightbearing results creates
"keystone in arch" effect
• muscles with fibers perpendicular to SI joint also generate
compression
• loss of SI joint motion hinders ability to dissipate forces
• Types of arch in body eg:
• Talus:- Keystone in med. Long. Arch of foot
• Cuboid: in lat. Longitiudnal arch
• Intermediate cuniform :- transverse arch of foot
• Capitate:- in carpal arch of hand

16. complex motion at the SI joint:
• gliding
• rotation
• tilting
• nodding (nutation)
– most common form of motion
– described as the backward rotation of the ilium on the sacrum
– counternutation is the forward rotaton of the ilium on the sacrum
• translation
• joint motion is limited to <4° of rotation and 1.6 mm of translation
• motion of the joint progressively decreased with age
– age 40-50 for men
– greater than 50 for women

17. PRESENTATION
• Symptoms
– pain patterns
• pain usually present just inferior to the posterior
superior iliac spine
– frequent pain referral area of other spine pathologies
– only 4% of patients will complain of pain above L5
– can radiate past the knee and into the foot
• wearing a tight fitting belt may improve symptoms

18. Physical exam
• inspection
– patients may have an antalgic gait
• palpation
– identify focal areas of tenderness
– sacral sulcus (most tender location)
– posterior superior iliac spine (second most tender location)
• motion
– evaluate hip and knee for underlying pathologies
• neurovascular
– in isolated SI joint dysfunction patients are neurovascularly intact
• pain-inhibited weakness may be present
• Dematomal pattern study by : slipmann at all shoes the distirbution of
symptoms as showen in pic.

19. provocative tests
• based on a battery of tests, no single test has 100%
diagnostic accuracy
• >3 positive tests is highly suggestive of the diagnosis
1. Patrick's test (FABER)
• also called flexion, abduction and external rotation test (FABER)
• patient will report pain in the SI joint with this maneuver
• groin pain suggests iliopsoas tendonitis or internal hip pathology
2. Fortin's finger test
• considered positive if patient localizes pain twice to region
inferomedial to PSIS
3. Gaenslen's test
• performed with the affected side hip extended off examination
table and unaffected side hip and knee flexed and held by patient
• shearing across SI joint causes pain

20. 4) SI compression test
o performed with patient laying lateral on exam table
o medial directed force applied over the iliac crest on the affected side
o reproduction of pain is considered positive
5) anterior sacral thrust test
o performed with patient positioned prone on the examination table
o anteriorly directed force is applied to the sacrum
o test is considered positive if pain is reproduced in the SI joint
6) SI distraction test
o with the patient supine on the examination table a posteriorly directed force over the ASIS
o test is considered positive when pain is reproduced in the SI joint
7) straight leg raise
o used to detect radiculopathy due to herniated disc
o usually negative in setting of SI joint dysfunction
o may be positive if leg brought above 60° of elevation
o caused by increased SI joint motion at this level of elevation
o Pelvic torsion test :-

21. Associated conditions
• Genetics
– HLA-B27
• associated with ankylosing spondylitis
• Associated conditions
– orthopaedic conditions
• lumbar spinal fusion
• post-traumatic arthritis
• metastatic tumors
– medical conditions & comorbidities
• anklyosing spondylitis
• gout
• pseudogout
• infections

22. IMAGING
• Radiographs
• recommended views :- AP, lateral, internal oblique, external oblique, inlet, and
outlet views of the pelvis
• to rule out other pelvic pathology :-
– flamingo views
– Indicated when there is suspicion of pelvic instability
– alternating single leg standing films of the pelvis
• SI joint views
• AP, lateral, flexion and extension views of the lumbar spine:- to identify other
spinal pain generators
• findings
– joint space narrowing
– subchondral sclerosis
– subchondral cysts
– osteophytes
– ankylosis
• sensitivity and specificity :- up to 25% of asymptomatic patients over the age of 50
will have abnoraml SI joints in radiographs

23. IMAGING
• CT :- indications
– has poor diagnostic power compared to SI joint injections
– deformity correction or surgical intervention is planned
• views
– pelvis and sacrum
• sagittal and coronal views
• 3D reconstructions
• MRI :- indications
– done to exclude other diagnoses
– identification of tumors, infectious process, or soft tissue
components

24. IMAGING
• Bone scan
– indications
• studies have reported on the predictive power of SI
joint pathology with SI joint injections
– sensitivity and specificity
• specificity - 90%(identify individual With disease +ve)
• sensitivity - 12% (identify person who has no disease)
• positive predictive value - 86%(person who is +ve and
has disease)
• negative predictive valuae - 72%( person who is –ve has
no disease)

25. DIFFERENTIAL
• Key differential (top 5)
– lumbar spinal stenosis
– degenerative disc disease
– hip osteoarthritis
– hip labral tear
– lumbar disc herniation

26. TREATMENT
• Nonoperative :-
– oral medication, physical therapy, pelvic belt, and prolotherapy
• Indications :- first line of treatment
• modalities
– oral medications
– mainly involve NSAIDS to reduce inflammatory process associated with
pain
– opioid medications should be used sparingly
– minimum of 4 week of non-operative modalities trial before
proceeding with SI joint injection
• physical therapy
– +/- hot/cold therapy
– treatment focuses on addressing core muscle strengthening,
proprioception, and flexibility to correct lumbopelvic and hip
biomechanics

27. TREATMENT
• pelvic belt
– belt that applies medial directed force on greater trochanters
• 4 to 8 inch wide belt that is applied around the greater trochanters
• external device that mimics the function of ligaments
– limits the motion and shear forces across the SI joint by providing
compression
• prolotherapy (controversial)
– phenol or glucose-based solutions (15% dextrose )injected at the base
of ligamentous complexes to induce scarring
– generates inflammatory response resulting in fibroblastic migration
and resultant scar that stabilizes joint
– (chemical Neurolysis:- rarely used- alcohole -30%-100%(95%ethyl
alcohol)
– Painful paresthesia and formation of neuroma is complication so rarely
used.

28. outcomes
• most effective in the acute phase of pain
– pelvic belt more effective for SI joint pain
following pregnancy
• prolotherapy more effective in the setting of
ligamentous laxity

29. SI joint corticosteroid injections
• indications
– second line of treatment
• outcomes
– 60% success rate in pain relief at 6 months
• >75% reduction in SI joint pain following a single
injection is confirmatory of the diagnosis
• >50% reduction in SI joint pain following two injections
– lower success rate in patients with previous
lumbar fusion

30. radiofrequency ablation
– indications
• third line of treatment
• technique
– targets lateral branches of the sacral nerve roots
– Types: Thermal (tem. 42*)/ Pulsed/Cooled
RF(better, less neuroma chances)
• outcomes
– efficacy is limited due to the inability to denervate
the anterior neural structues of the SI joint

31. Others treatment modality
• Hylourenic Acid: for joints lubrication; decrease friction
on joints+ mixed with steroid
• PRP + Local+ steroid: Local+ steroid: immediate acction
• PRP long action
• Bone marrow mesenchymal stem exosomes:- ( could
relieve pain of OA via abrogation of aberrant CGRP-positive nerve and
abnormal H-type vessel formation in the subchondral bone of SI joints)
• membrane-umbilical cord and
• sarapin ( plant-derived suspension obtained by Sarraceniaceae
pupurin, and acts on pain pathways by obliterating the potential of C-
fibers )

32. Operative
• open SI joint arthrodesis
• indications
– confirmed diagnosis of SI joint dysfunction as primary pain
generator
– poor response to nonoperative treatment options
– patients with aberrant SI anatomy, sacral dysmorphism, or
revision surgery
– previously infection was the only indication for arthrodesis
• outcomes
– new literature with favorable outcomes in appropriately
selected patients

33. minimally Invasive SI joint arthrodesis
• indications
– confirmed diagnosis of SI joint dysfunction as primary pain
generator
– poor response to nonoperative treatment
– normal SI joint anatomy
• outcomes vs. open
– shorter hospital stay
– smaller incision
– theoretical decrease in surgical site infections
– decreased limitation of postoperative weight bearing
– quicker return to full weight bearing than open arthrodesis
– decreased blood loss

34. TECHNIQUES
– SI joint corticosteroid injections
– technique
» performed under fluoroscopy or ultrasound guidance
• studies have shown that without imaging the injection is in the SI joint only 22% of
the time
» can be used as both a diagnostic and therapeutic injection
» no more than 3 injections in a 6 month prior or 4 injections in 1 year
» Due to short lived life of steroid repeat injection required; works for about 6 months
– Radiofrequency ablation
• technique
– targets lateral branches of the sacral nerve roots
– dorsal nerve ramus ablation
» L5-S3 dorsal rami innervate SI joint
» Nerve Regeneration & ant. Ramus not blocked- works 9-12 months
– Open SI joint arthrodesis
• approach
– performed through posterior approach (anterior is limited by vital neurovascular structures)
• technique
– cartilage is removed and bone graft is packed into the obliterated space
– stabilized with posterior plate and screws, iliosacral screws, or cage construct
– made protected weight bearing for 12 weeks following surgery

35. – Minimally invasive SI joint arthrodesis
• approach
– percutaneous placement of implants
• technique
– newer techniques involve triangular titanium porous coated implants
– "fusion" occurs by bone growth onto the implant rather than direct
fusion of the joint
– requires multiple implants placed across SI joint to achieve stability
• complications
– patients with a dysmorphic sacrum have a higher risk of iatrogenic
nerve injury

36. COMPLICATIONS
– Surgical site infections
• risk factors
– immunocompromised
– smoking
– diabetes
– Wound complications
• risk factors
– open surgical technique (wound is located in the dependent position)
– Nerve injury
• risk factors
– minimally invasive technique
– sacral dysmorphism
• injury to the L5, S1, or S2 nerve roots
– Pseudoarthrosis
• occurs in up to 5% of cases
• revision arthrodesis with open surgical technique

37. PROGNOSIS
• Natural history of disease
– quality of life of patients with SIS is more affected
than patients with chronic obstructive pulmonary
disease and mild heart failure
– equivalent to patients with hip and knee arthritis