SI joint

ipsilateral side bending

increases shearing stress to ipsilateral SI

SIJ dysfunction: clinical presentation

• Almost always unilateral • Hypermobility is the predominate problem • Pain comes/goes/remains constant irrespective of posture • correlated to positive Fortin finger sign • Usually no abnormal neuro signs • Discomfort standing or lying on back (loaded) - Relieved with movement • SLR may be positive for pain but is usually when hip flexion angle over 60 degrees • sxs exacerbate with WB, stairs, and walking • pain intensity doesn't usually increase with prolonged sitting • there will be no findings of parasthesias, numbness or weakness because no true neuro signs

pt education for SIJ dysfunction

• Avoid activities (temporarily) that will promote asymmetry: - when standing, don't stand with weight on 1 leg - sitting with hips abducted promotes the most stability at SI joint; Absolutely no crossing the legs (not at the ankle or knee) • when pt comes back in, check them again and reduce again if the reduction did not stay - continue to reinforce activity restrictions - Add new restriction: don't carrying heavy things on 1 hip

Form closure is provided by:

• Configuration of interfacing joint surfaces • Dorsocranial wedging of sacrum into ilia • Complimentary wedges and grooves on articular surfaces - the irregularities between articular surfaces (ridges and depressions) are structural stabilizers • High co-efficient of friction because of irregularities in surface • Integrity of binding ligaments

sacral anatomy

• Dorsum convex • Ventral surface concave • Lateral aspect - " " L " " shaped articular (auricular) surface - Short arm more vertical - Long arm more anterior-posterior

SIJ: supported network of musculature

• Functionally connected to SI joint • Deliver regional muscular forces to pelvic bones - Gluteus maximus & minimus - Piriformis - Biceps femoris - Erector spinae - Latissimus dorsi - Iliacus - Thoracolumbar fascia

SI joint movements

• Innominate motion on sacrum - Anterior /posterior torsion - inflare/outflare - cephalic shear/caudal shear (translation) • Sacral motion on innominate - Nutation /counternutation

posterior oblique sling

• Latissimus dorsi and contralateral gluteus maximus, biceps femoris • sling operates/is functional during loading - ipsilateral glut max will fire and contralateral lat fires (produces a set of forces that helps to stabilize the SI as well as the pelvis) - result of that is a load transfer through pelvic girdle - this is seen functionally during loading phase of gait • if you take a brisk walk with SIJ dysfunction - carrying 2 lbs in hands going to promote SIJ stability through posterior oblique sling activation • this sling system is a dynamic stabilizer

etiology of SIJ dysfunction

• Mechanical - Trauma (misstepping off curb, MVA) - LLD - Excessive lordosis - Spinal/hip fusion (fusion of joints above or below creates excessive stresses at SI) • Hormonal • Inflammatory

longitudinal sling

• Multifidus attaching to the sacrum • Deep layer of the thoracolumbar fascia • Long head of biceps attaching to the sacrotuberous ligament • connects peroneals, biceps femoris, sacrotuberous lig, thoracolumbar fascia, and the erector spinae - some sources include multifidi • purpose of longitudinal sling is to counter sacral nutation - faciliates compression through SIJ

force closure is provided by:

• Nutation is essential in force closing - causes Posterior parts of iliac bones to be pressed together - sacral nutation is the most effective position for transferring loads from the sacrum to the innominate and into the LEs - in sacral counternutation, some of that stability is lost • Components of force closure - Combination of regional & local ligaments - Muscles - Fascial systems - Gravity

SI joint dysfunction

• Pain in or around region of joint that is presumed to be due to malalignment or abnormal movement of SI joint • universally accepted as source of LBP or buttock pain with or without LE pain • will potentially see similar symptoms as intervertebral disc problems or issues with the facet joints; ability to differentially diagnosis becomes critical • women are 6x more likely to experience SI dysfunction than men • SIJ dysfunction produces pain and is also capable of referring pain • SIJ can be directly or indirectly involved in LB problems

SIJ dysfunction: goals of treatment

• Pain management - cold or heat - deep structure, so modality is likely not effective • Correction of joint position - reduce joint (restore anatomical alignment) with mobilization or muscle energy techniques • Patient education

anterior oblique sling

• Pectorals, external oblique, transverse abdominus, anterior abdominal fascia, contralateral internal oblique and hip adductors • in this sling the obliques will act as phasic muscles to initiate movement • anterior oblique sling is involved in all trunk movements as well as movements of upper and lower limbs - only time it is not active is when individual is in a position where legs are crossed over one other

SIJ innervation

• Posterior SI joint innervation ambiguous - Lateral branches L4-S3 dorsal rami - L3 and S4 contribute to posterior nerve supply • Anterior joint via studies also ambiguous - L2-S2 - L4-S2, - L5-S2 ventral rami

effect of R posterior innominate torsion

• Right acetabulum moves cranially • Coccyx deviates left • Pubic symphysis displaces • Right sacral base tilts downward • Lumbar spine SB left & rotates right - Obstructs right intervertebral foramina - Right disc compression - Stretches left iliolumbar liaments - Stretches right sacrotuberous & sacrospinous ligaments • a torsion can create local sxs, radicular sxs, and sxs in buttock region

SI joint characteristics

• SI joint is the largest joint in the axial skeleton • it is a true diarthrodial joint that joins the sacrum to the pelvis • Moveable and weight bearing • Plane of joint lies between sagittal & frontal planes - Wider sacrum anteriorly than posteriorly • Only S1-S3 contribute to joint • Axis controversial & variable • Numerous ridges & depressions on articular surfaces - Provides stability • Well saturated with nociceptors and proprioceptors (SIJ issues are very painful) • there is a capsule surrounding SI joint

SIJ dysfunction: pain behavior

• SI pain around PSIS when turning in bed, getting out of bed, or stepping with involved leg • Often constant regardless of position - not mechanical - constant because once you set off inflammatory response, you wind up with pain • May have pubic symphysis pain occurring simultaneously with SI pain - May increase with rectus abdominis or hip adductor contraction • Baer's point - 1/3 of distance from ASIS to umbilicus - area where pain is referred from SI joint or iliopsoas • Walking, standing, ascending & descending stairs - These stress SI joint and may be especially provocative in someone with dysfunction

SIJ dysfunction: mechanism of injury

• Sudden jarring movements - generally mechanism of injury is a combo of axial loading & abrupt rotation - Ex: stepping off curb and not expecting it • Intra-articular causes - Arthritis (DJD) - Infection • Extra-articular causes - Fracture (at SI or pelvic rim) - Ligamentous injury - anything that disturbs the integrity of the pubic symphysis

functional movement patterns

• Symmetrical motion - Movement of both innominates relative to sacrum - this is pelvic motion: anterior, posterior, and lateral pelvic tilts • Asymmetrical motion - Antagonistic motions of each innominate relative to sacrum - posterior and anterior torsion, outflares, inflares - asymmetrical motion inherently means that the pubic symphysis is also moving • Lumbopelvic motion - Rotation of Spine & both innominates around femoral heads

Anterior SI ligments

• Transverse • Longitudinal • Oblique • assist the pubic symphysis in resisting separation or horizontal movements of the innominates at the SI joint

risk factors for SI dysfunction

• True/apparent LLD - discrepancies in LLD could lead to irritation of SIJ - SI torsional or shearing injuries could cause discrepancies in leg length - like the chicken and the egg, which came first? • Gait abnormalities • Prolonged vigorous exercise • Scoliosis • Spinal fusion to sacrum • Lumbar spine surgery • Pregnancy - Increased weight gain - Increased lordotic posture (more load anteriorly) - Trauma at childbirth - Hormonal ligamentous laxity

SI joint axis and ROM

• Two fixed axes theory - axis at Junction of cranial & caudal aspects sacral surface - another axis runs Posterior to pubic symphysis • Rotation around all three cardinal plane axes - Rotation mostly in sagittal plane - .2-3.0 degrees • Translation in 3 dimensions - 1-3 mm • greatest amount of motion in young pregnant females

SI joint clinical testing

• Two types - Palpation of bony landmarks with or without measurement (Mobility testing) - Pain provocation tests • Suggested a combination of SI joint provocation tests is useful in pinpointing SI joint as cause of symptoms in those with pain below L5 vertebra • a combo of tests contained sufficient discriminating power for diagnosing SI pain - Thigh thrust test - Compression test - 3 or more (+) stressing tests • Key clinical tests: - Distraction - Compression - Thigh thrust - Gaenslin - Sacral thrust

radiofrequency ablation

• Used after SI injection has determined that SI is cause of symptoms • Probe burns sensory nerves - Not always successful - Effects temporary, Up to 2 years max

diagnostic imaging for SIJ dysfunction

• X-rays - shows Joint abnormalities, but normally won't see anything on x-ray • CT scan - More detailed joint surfaces & surrounding bone; not common for SIJ dysfunction • Bone scan - Inflammatory conditions • MRI - Not used • Fluoroscope Injection - most commonly used - Local anesthetic injected into SIJ under fluoroscopic guidance - if it takes away pain, this is diagnostic

hip adduction

• adductors stress pubic symphysis - indirectly affects SIJ through the pubis

posterior SI gapping test

• also called compression test or ilium ventromedial provocation test • gaps posterior aspect of joint and creates stress to posterior SI ligaments • pt is sidelying • be high enough so examiners arms can be extended • stay on anterior 1/3 of lateral aspect of innominate • put one hand on top of the other • push down • positive = reproduction or exacerbation of pain in area of PSIS

anterior SI gapping test

• also called distraction test or ilium dorsolateral provocation test • this test gaps the anterior aspect of the SI joint, therefore stressing the anterior SI ligaments • pt is supine • hands will cross over with base of palm just inside the front of the iliac crest • push posterolaterally with both hands • this is a tough test for some because it is a sensitive area - may have to put towel roll between hand and innominate • positive = reproduction or exacerbation of pain in area of PSIS

Piedallu test

• also called sitting flexion test • assesses restriction or hypomobility of the SI joint • pt is in a short sitting position on a firm surface • ask pt to cross their arms over their chest • may want footstool under their feet, since they are really bending forward, don't want them to feel like they will fall • examiner is behind, palpating PSIS • slowly ask pt to curl forward, creating segmental movement that is initiated from above (not bending at waist) • pt will move L5 on S1, and then you will have movement at SI joint; you are waiting to feel movement of the sacrum (you will feel it displace upward) • normally, both PSIS will move up at the same time and go the same distance • positive for hypomobility = affected side will move prematurely (earlier) than unaffected side • as the kinetic chain moves down, sacrum will nutate first, taking up movement at SI joint - if hypomobile at SIJ, sacrum can't nutate and the SI joint will move together

Gaenslin test

• also referred to as passive hip extension test • assesses the integrity of the SI joint and the hip • pt is supine on the table, with leg far enough off side of table that innominate that you are assessing is off the edge of the table • pt will bring hips and knees into flexion and hold the nontest limb in that position • examiner passively and slowly lowers the test limb down into hip extension • ask pt how they feel; where are sxs? - positive gaenslin for nonspecific SI pathology = pain that they relate back to PSIS area - positive gaenslin for hip pathology = pain in inguinal (groin) area

differential dx of SIJ dysfunction

• ankylosis spondylitis (also called Marie-Strumpell, one of the early signs is sacroiliitis) • hip fx • hip overuse • ITB • disc/facet and radiculopathy from lumbosacral area • piriforimis syndrome • trochanteric bursitis • infection in the area

multifidus

• anticipatory stabilization of LS spine - recruited before movement of UE or LE • co-contraction of TA and multifidus increases stiffness of SIJ • bilateral contraction: - may produce posterior pelvic tilt due to attachments with erector spinae, PSIS, and posterior SI ligaments

caudal shear

• assesses shear at SI joint • pt is prone • one hand at base of sacrum and the other hand wedges on ischial tuberosity • push in opposite directions creating shear • positive = pain in and around PSIS • shear isn't really common, typically seen with people falling on one side - most of what we see clinically are torsions of SI

Supine to sit test

• assessing torsion (anterior or posterior) • pt is supine, make sure they are straight • assess leg length discrepancy (measure true and apparent) • if pt doesn't have significant leg length discrepancy, proceed with test • examiner puts thumbs on apex of medial malleoli; thumbs should be oriented in the same plane • ask pt to come to sitting position with legs extended; keep thumbs on malleoli • in long sit position, assess relationship of L and R thumbs; should still be symmetrical

gluteus maximus

• bilateral contraction: - causes posterior pelvic rotation through sacrotuberous and posterior SI ligaments • unilateral contraction: - causes ipsilateral posterior rotation of innominate

quadratus femoris

• bilateral contraction: - stabilizes lumbar spine - sacral nutation through attachments to sacral base and ala • unilateral contraction: - causes ipsilateral SB when pelvis fixed - eccentric control of contralateral SB

external rotators and Piriformis

• bilateral piriformis contraction: - produces anterior force on sacrum (nutation) • unilateral contraction: - anterior force causing rotation to opposite side

pain with SIJ dysfunction

• classically point tender over PSIS - Pain from SI dysfunction is never in the midline - always caudal to the PSIS • pain may be referred to S1-2 dermatomes (upper medial buttock area) • pain may refer in distribution of sciatic nerve, but rarely goes below the knee • may have pubic symphysis pain which can radiate into the lower abdomen and genital area

cephalic shear

• come up under apex of sacrum (don't want to put a lot of pressure through coccyx) • get hand on top of iliac crest • push in opposite directions • positive for SI dysfunction = pain in and around PSIS

lateral sling

• connects glut med and glut min, TFL, and the thoracopelvic lateral stabilizers • primary function of lateral sling is to stabilize pelvic girdle on the femoral head during gait • in people with instability at SIJ, many of these muscles are reflexively inhibited - this is the rationale for why we address core muscles for pts with pelvic and lower limb stability

diagnosing SIJ dysfunction

• diagnosis based on 3 things: - positive history - negative result on functional exam of lumbar spine - 3 or more positive findings in SI provocative tests

hip abductors

• directly influences SIJ through pubic symphysis • gluteus medius pulls ilium away from sacrum

Sacrotuberous and Sacrospinous ligaments

• do not directly cross the joint, but they indirectly provide stability • resists forward tilting (nutation) of the sacrum on the hip bone during weight bearing of the vertebral column • also limit posterior innominate rotation • sacrospinous ligament has an attachment to the coccyx and can refer pain to that structure • sacrotuberous ligament often refers pain to the buttocks and the hip

SIJ neurotomy

• essentially denervates the SI joint • this is a drastic measure, will likely see a fusion before they try ablation or neurotomy

force closure

• extrinsic factors that help to stabilize the joint • Result of altered joint reaction forces by tensing ligaments, thoracolumbar fascia, muscles & ground reaction forces - Increases joint friction & stiffness - Controls shear forces • amount of force closure that is needed is an individual matter: depends on the person's form closure (anatomy) and loading conditions (magnitude, duration and velocity of forces)

Importance of positioning for SIJ dysfunction

• if hypermobility is the predominant problem and you reduce the joint, but they aren't compliant with postural instructions, it will go out again because it is hypermobile • since we don't have direct mm support and the ligaments are lax at times, if someone has these torsional problems we have to rely primarily on ligamentous restraints - down the road we can work on muscles, but acutely when they are not stable we try to keep that joint reduced and still to promote stability by allowing scarring to occur in and around inflamed ligaments • we are not doing any exercises for the first several sessions - just reduce joint and provide education on posturing - if we need to reduce it every time they come in, we may need to think about an external support to stabilize the pelvic rim (SI belt)

injections

• if pt doesn't respond to conservative measures, they can do an injection guided by fluoroscopy • injection may be done to decrease Inflammatory process like sacroilitis, which won't respond to conservative measures • Sclerosing injection - not commonly done, but it works well - used if pt is hypermobile and unstable - inject substance that is meant to create scar tissue

associated movements affecting SI joint

• indirect effect: contraction results in mechanisms that provide support or tend to disrupt the joint, but they are not attached to the joint • FB lumbar spine • Hip flexion • Hip abduction • Hip adduction • Hip extension • Ispilateral SB (increases shearing stress to SI joint)

force closure: muscles that resist translation forces

• inner muscle group: - transversus abdominus: significantly decreases laxity of the SI joint, and helps to produce forces that approximate the anterior innominates - pelvic floor muscles: co-activate with the TrA during lifting tasks - multifidus: in people with LBP or pelvic pain, multifidus becomes inhibited and over time will atrophy • outer muscle group - referred to as the global muscle system - several muscles that produce forces and act as integrated slings in providing stability and support to the SI joint - there are 4 separate sling systems that stabilize the SI joint as well as the pelvis

innominate upslip/downslip

• innominate is moving component, translating on the sacrum • Upslip - Superior translation of innominate on sacrum - ASIS, PSIS, Iliac Crest displace superiorly relative to uninvolved side • Downslip - Downward translation of innominate on sacrum - ASIS, PSIS, Iliac Crest displace inferiorly relative to uninvolved side • caused by: true LLD, SI shear injury, lumbar spine pathology (significant muscle spasm)

innominate anterior/posterior torsion

• innominate moves on sacrum • anterior torsion - ASIS displaces inferiorly, PSIS displaces superiorly • posterior torsion - ASIS moves superiorly, PSIS moves inferiorly

SI joint stability

• joint is designed for stability • in the erect position, the SI joint is subjected to a lot of shearing forces due to the mass of the upper body having to be transferred to the lower limbs (through ilium, innominates, SIs, and to LEs) • Self locking mechanism • Form closure • Force closure • Large ligaments

posterior SI ligaments

• long posterior SI ligaments - help to limit anterior pelvic rotation - are slack during sacral nutation and become tightened/taut in sacral counternutation - resists counternutation of the sacrum on the hip bone during weight bearing of the vertebral column • short posterior SI ligaments - limit all pelvic and sacral motions from being excessive

muscle slings responsible for SI force closure

• longitudinal sling • posterior oblique sling • anterior oblique sling • lateral sling • other muscles - diaphragm - pelvic floor

sartorius

• may exert anterior effect on innominate when knee is slightly flexed and hip is extended

secondary ligaments

• more superficial • react to dynamic motion during physical movements • sacrotuberous and sacrospinous ligaments • iliolumbar ligament

SIJ ligaments

• much of the stability comes from self-locking mechanism and network of ligaments that are in the area • ligaments are extremely strong • when the sacrum nutates (forward bending), there is an increase in the tension in the major ligaments of the SI joint during load bearing situations (standing, sitting, walking) • in sacral counternutation, there is a slackening of the major ligaments when the SI joint is minimally loaded (supine, prone, sidelying)

interpreting supine to sit test results

• points of interest are ASIS and acetabulum • posterior torsion - when pt is supine, acetabulum moves superior and leg appears to be shorter - ipsilateral malleolus will appear to be more cranial than the contralateral malleolus - when pt is in long sit, acetabulum is more distal, innominate has not rotated as far as the other, ipsilateral malleolus is more distal, limb appears to be longer • anterior torsion - acetabulum moves inferior and leg appears longer - anterior torsion in long sit, acetabulum is more cranial, so limb appears shorter • supine to sit test in absence of any leg length discrepancy - the shorter limb in supine that becomes the longer limb in long sitting is a posterior torsion of the innominate - anterior torsion of innominate will display a longer leg supine that becomes the shorter leg in long sit • you would know which leg based on the symptomatic side

observation: SIJ dysfunction

• postural inspection - palpate ASIS, PSIS, iliac crest, S2 tubercle • palpate pubic symphysis - changes at SIJ alter symmetry of pubic symphysis • palpate sacral sulcus (the hole below the PSIS) - palpate for symmetry of depth - if one side is deeper, may be indicative of a torsion • gait observation - SI lesions/dysfunctions can produce trendelenberg gait or contralateral sidebending of stance limb

sacral thrust

• pt is prone • examiner put hands on sacrum and thrust it anteriorly • positive = reproduction of pain or exacerbation of existing pain - pt will indicate pain at PSIS area

thigh thrust test

• pt is supine, hip flexed 90 degrees, knee is fully flexed • examiner is on the symptomatic side (flexed side) • create a posterior shearing force to the SI by pushing posterior through long axis of femur • make sure that you avoid any deviation out of the sagittal plane • some clinicians will put other hand in the area of the PSIS to be able to palpate any movement • positive = reproduction or exacerbation of any existing pain - sxs in the area of the PSIS

SI joint fusion

• put 2 metal screws through the joint to stabilize it • with fusion, must be concerned about abnormal stresses to lower lumbar curves

form closure

• refers to the state of stability within the pelvic mechanism that is dependent upon the anatomy with no need for any additional forces to maintain the stable situation of the joint • Stable joint situation with closely fitting surfaces • No extra forces are needed to maintain the state of the system, given the actual load • Flat surfaces - Promote stability & load transmission - Susceptible to shear forces

iliolumbar ligament

• runs from the transverse processes of L4 and 5 to the iliac crest and the SI joint to the capsule • function is to stabilize L5 on the ilium • these are also the furthest ligaments away from the SI joint • also function to restrict movement at the L-S junction, especially side-bending movements • as the furtherest ligament, it has more stresses imposed upon it and can be the source of sxs

SI belt

• small, some have sacral pad • goes around pelvis area, pretty snug • wear SI belt all the time (even to bed) at first; once SIJ is stable, can gradually wean from SI belt • After a couple weeks you will notice that they seem to be pretty stable, so then you can add in exercises

interosseus ligament

• strongest of the SI joint supporting ligaments • massive set of fibers that fills most of the space along the posterior and superior margins of the joint • in doing so, this provides significant multi-directional stability to the joint • resists anterior and inferior movement on the sacrum

exercise for SIJ dysfunction

• target the core/sling muscles • early on stay away from asymmetrical exercises (no biking, no stair master, no quadruped with alternating limb extension) • as they progress and remain stable, you can increase intensity of exercises

SI joint articular surfaces

• the ilium surface is predominantly considered to be convex - it is composed of a thin fibrocartilage • the auricular surface (sacrum) is generally considered to be concave - it's surface is composed of a thicker hyaline cartilage

primary ligaments (deep)

• the job of the deep ligaments is to resist the load of the sacrum relative to the innominate • Anterior SI ligaments - Transverse - Longitudinal - Oblique • Posterior SI ligaments - Long posterior SI ligaments - Short posterior SI ligaments • Interroseus

hamstrings

• tightness can cause posterior innominate torsion

torsion vs shearing injury

• torsions make up 95% of SIJ dysfunction • shearing injuries are less common, tend to occur with trauma - fall onto side, ground reaction force goes up through ischial tuberosity causing an upslip on that side

abdominals

• transverse abdominus contributes to SIJ stiffness • contraction of abdominals stresses pubic symphysis, potentially stressing SI joint

innominate inflare/outflare

• transverse plane motion; innominate moves on sacrum • inflare - ASIS displaces medially, PSIS displaces laterally • outflare - ASIS displaces laterally, PSIS displaces medially

Self locking mechanism

• weight of the superincombent body coming through axial skeleton and crossing into an through SI joints and into the LE • opposed by ground reaction forces coming up from below • you end up with a very stable pelvic ring

iliopsoas

• when pelvis and femur are fixed: - produces ipsilateral flexion of lumbar spine with contralateral rotation - flexes lumbar spine relative to pelvis, decreasing lordosis • when lumbar spine and pelvis are fixed: - produces hip flexion and ER • bilateral contraction: - iliosoas blends with anterior SI ligament and attaches to ala of sacrum - produces anterior pelvic rotation and sacrum • unilateral contraction: - causes anterior innominate torsion - ipsilateral sidebending

rectus femoris

• when pelvis is fixed: - flexes thigh on pelvis • when thigh and lumbar spine are fixed and pelvis is free to move: - can cause anterior rotation of ipsilateral innominate