SI joint Assessment Flashcards
SI joint articulation
- 2 ilia with sacrum
- iliac crest comes to around L4-L5 interspace
- Apex is inferior to base
SI joint: articular anatomy
- irregular
- interlocking surfaces = little motion
- aging and degeneration increases interlocking = less motion
SIJ articular anatomy
Articular cartilage
- sacral - hyaline cartilage thicker 2.5 mm
- ilial fibrocartilage thinner
SIJ articular anatomy
Pubic symphysis
- hyaline cartilage
- fibro-cartilagenous disc
- ligaments (anterior, inferior, posterior, superior)
SIJ gender differences
Males:
- < mobility more stability
- surface area larger
- morer irregular surface
Females:
- smaller/smoother surface area
- hormonal changes (relaxin)
- pregnancy stresses
- SIJ sits more posterior/more posterior torsion forces on the ilia
What gives the SIJ stabiliity
Form fit
Force closure:
What gives the SIJ stabiliity: form fit
Form fit
- osteologic locking
- scarum is wedged between ilia
- BW from above and ground reaction forces up through LE futherr wedges it
What gives the SIJ stabiliity: force closure
Force closure:
- from musculature
- lats, thoracolumbar fascia
- glute maximus
- Obliques
- abdominal fascia
- hip adductors/abductors
What are the mechanical relationships at the SIJ
- LEs to innominates -ground Reaction forces of LE into acetabulum affect innominates more
- spine to sacrum -spine forces affect sacrum more
Ilial movements on the scarum
- minimal movement: translation = 2mm and rotation = 4º
- posterior ilial rotation = linked with hip flexion
- anterior ilial rotation = linked with hip extension
Accessary ilial movements (translations or glides)
- anterior translation: occurs with anterior ilium rotation
- posterior translation: occurs with posterior ilium rotation
- Superior translation: is an upslip of ilium on sacrum
- inferior translation: is a downslip of ilium on sacrum
- ER: outflare; anterior translation of ilium occurs
- IR: inflare; posterior translation of ilium occurs
Sacral movements
- also small; rotation = 2ºand translation 1-2 mm
- sacral flexion (nutation) = sacral base goes anterior => sacral sulcus deepens
- Sacral extension (counter-nutation) = sacral base goes posterior => sacral sulcus shallows
Posterior intrinsic interosseous ligaments at the SIJ
- both limit posterior separation of ilium from scarum and sacral flexion; long also limits ilia upslip
- interosseous and short posterior SIJ ligament
- longer posterior SIJ ligament scarum to PSIS
- also anterior SIJ ligament that limits anterior separation of iliam frorm sacrum
Posterior extrinsic ligaments
- extrinsic ligament limit ilial posterior rotation and sacral flexion
- iliolumbar ligament also limits anterior translation of L5
- sacrospinous limits posterior rotation of ilium/sacral flexion
- sacrotuberous anterior and posterior rotation of ilium, sacral flexion
Musculature acting on ilium for
anterior rotation of ilium
- iliopsoas
- rectus femoris
- TFL
- sartorious
- hip adductors
Musculature acting on ilium for
Posterior rotation of ilium
- gluteus max
- hamstrings
- abdominals
Musculature acting on ilium for
Superior translation of ilium
- quadratus lumborum
Musculature acting on ilium for
pelvic stabilization in frontal plane
- abductors
- adductors
Musculature acting on scarum for
sacral extension
- lumbar errector spinae
- multifidi
Musculature acting on scarum for
sacral flexion
- piriformis: anterior sacrum to greater trochanter
SJI pain presentation = source most likely
- 40% disc
- 15% facet
- SIJ 13%
- other 11%
- Disc modic 10%
- NR 10%
- stenosis 1%
What happens with each of these scenerios
- if no centralization (-disc) and (+) SIJ provocation tests
- If no centralization (- disc) and (-) SIJ provocation test
- then probability of SIJ increases
- then probability of facet joint increases
however facet joint reference standard is diagnostic anesthetic injections
What happens when you rule in SIJ as a pain souce
- can be SIJ dysfunction: aberant position or increased movement at SIJ = instability
- Pain from SIJ articulation structures (intrinsic)
What are some intrinsic causes of SIJ articulation pain
- intra-arrticular inflammatory conditions: sacroiliitis, DJD
- inject anesthetic into SIJ and if decreased pain and inflammation it confirms pain intrinsic to SIJ inself
SIJ S&S
- nocioceptic pain; nocioplastic - psychological/chronic
- acute = sharp, lcoal assoicated with trauma
- chronic = SIJ instability, DJD- more diffuse pain
- pain is usually unilateral
- pain palpation of dorsal ligaments
- ispilateral muscle guarding in ES, multifidi
- pain increased with provocation - springing, gapping, torsion
- worse standing (esp. on one leg) walking, stairs, stepping down off curb, hop on involved LE
Intra-articular injection
- local anesthetic
- diagnostic of SIJ pain but not pain from extra-articular extrinsic ligaments
- injection often done twice to rule out false positive
- determine a significant clinical response
SIJ injury
Posterior rotation ilium on scarum: sprain/pain MOI
- persistent one leg standing
- fall on ischial tuberosity
- vertical thrust on extended leg (falling off a ladder, land on heel, miss step)
- intercourse position
- birthing process
SIJ injury
Anterior rotation of ilium on scarum: sprain/pain
MOI
- horizontal thrust on knee w/ hip flexed - MVA
- Axial load through femur
- golf swing
Exam
what clinical tests can be used for SIJ
- static tests: palpation/look for asymmetry
- passive mobility tests: manually moving ilium or scarum to assess amount of motion and joint play
- dynamic tests: patient performs active motion s as PT performs landmark palpation to assess SIJ movement
- provocation test: SIJ spring torsion test to elict pain (most reliable)
Examples of provocation test
- distraction: hands on ASIS foring them apart
- Compression: iliac compression sidelying
- thigh thrust:
- Gaensalens test; pelvic torsion
- FABER
what is the clinical prediciton rule for SIJ
- 3 or more + SIJ provocation test
- centralization does not occur with repeated ROM or sustaing positions
SIJ provcation test: drop test
- get a force going through SIJ but going up on two legs (calf raise) and then leaning to one side
Pain descriptors that lend to support SIJ dx
- the absence of pain in the lumbar region
- pain below L5
- pain in the region of the PSIS
- pain in the groin area (if pubic symphysis is involved)
Pelvic girdle PT managment
overall what should be addressed first
- first correct lumbar and hip problems => SIJ problems may resolve
- then correct pelvic/SIJ dysfunction: decrease pain, restore alignment via manual techniques
- if pubic pain first correct pubic alignment
- muscle re-education/stabilization exercises
- lengthening, strengthening of muscle imabalnces
- suppot - SIJ belt worn jest below ASIS
Non PT interventions
for SIJ dysfunction
- injections: anesthetics into joint or glucocorticoids (between diffusion into extrinsic liagments)
- minimally invasive SIJ stabilization surgery
Supine to sit test - results mean what?
- If one side goes from relatively short in supine to relatively long in long sitting it is said that the pelvic innominate on that side is in posterior rotation.
- If one side goes from relatively long in supine to relatively short in long sitting it is said that the pelvic innominate on that side is in anterior rotation.
