Clinical Reasoning of Lumbar Spine and SI Joint Dysfunction - Dr. Swapnil Mate

Intervertebral Disc in the lumbar spine is constructed similarly to that of other parts of the vertebral column. the disc has two components, Annulus Fibrosis forming an annular wall for Nucleus Pulposus.

The annulus fibrosis is constructed of annular rings of collagen fiber 

(chondrocytes which produce proteoglycans and fibroblast which produce type 1 collagen)

Fibrocartilage Annulus is attached firmly by cartilage endplate to the vertebrae above and below. Nutrition to the disc is via diffusion through cartilaginous endplate which is 1 mm thick.  

Attachment of annulus fibrosis is not firm on the posterior aspect. Moreover, the posterior longitudinal ligament with which its blend is weak compared to the anterior and lateral part. 

(the reason why Nucleus pulposus have high chances of protruding it more posterior...)

Nucleus pulposus, the central part is transparent jelly and made up of water and mucopolysaccharides. (proteoglycans and type II collagen)

(as age advance the water content reduces, increases the compressive load on the disc causing the high prevalence of low back post 45 -50 yrs.)

The main function of pulposus is to absorb and transmit axial compressive forces across the lumbar spine and provide a cushion.

as well as having hydrodynamic and biomechanical properties, intervertebral discs have a proprioceptive role. 

Passive mobilization and early movements help to recover the proprioceptive feedback.

How Disc Influence the posture.

Sustained and repeated flexion movements, stresses the nucleus to come posterior, this coincides with the increased intra-discal pressure increasing stress of annulus fiber to tear apart, mobilizing the disc further posterior to bulge.

if the tear happens central, kyphotic posture is adapted

if the tear happens lateral, scoliosis posture is adapted.

if the hydrostatic pressure is lost from the disc, the flat back is noticed.

(reduced Lordosis is seen  in chronic case-patients)

Why Early Movement is encouraged.

Nucleus pulposus tear the annulus fibrosis attached to the vertebral endplate (hyaline cartilage) through the radial fissure. Natural healing starts from the vascular endplate, sends vascular supply to avascular disc promoting healing, which causes scar formation.

Contraction of invading scar formation on an elastic annulus fiber leads to the formation of the fragment within the fiber, leading to the dysfunction, causing a loss of mobility in the involved segment.

when sufficient stress (exercise) is involved at the segment, scar breakdown and make it more elastic

(the reason why early movement or exercise is encouraged)

Spondylosis - Degenerative Disc Disease:

Disc losses much of its vital blood supply during the first decade of life. once age advances the water is depleted, the drop in water and proteoglycan content is one of the classic signs of disc aging.

because of this dehydration, there is a weight-bearing shift that occurs from the nucleus to the outer annulus, ring apophysis, and zygapophyseal joints.

vertebral bodies have special channels called marrow cavities which allows diffusion to occur. as long as these channels are open, the cells of the disc get their needed oxygen, glucose, sulfur and other nutrients, as well as the removal of waste metabolites. 

as age advance, the marrow cavities become narrowed or closed from bone, which in turn starves the disc cells to death. leading to spondylosis changes.

Nerve Circulation

No prominent Nerve supply to disc, except the posterior part of the annulus, receives it from

sinu- vertebral nerve. 

the lateral side from lateral rami, 

and the anterior disc by sympathetic branches from the sympathetic trunk or ganglion. 

Which SEGMENT

L4 - l5 / L5 - S1 is more common as load and center of gravity pass through it, the segment bears more weights, more movements, more axial compressive force and it is the junction where mobile segments intersect with the non-mobile segment.

McKenzie - 

Alteration in the arrangement in the disc physiology - The Derangement Syndrome - 

(constant ache and loss of partial  range or full movement or completely locked)

Alteration in the bony segment - The Dysfunction Syndrome, Mechanical LBP.

(pathology in muscle, ligament, fascia, facet, and disc)
intermittent pain and partial ROM restriction.

Disc pain is usually constant due to chemical response or inflammation. 

Soft Tissue dysfunction intermittent due to vascular supply, stretch, and movement of the tissue. sustained pain due to prolonged position or frequency of the movement. 

refereed pain below knee and other symptoms confirm about the disc prolapse. else most back pain is predominantly seen in the lower back and gluteus region.

Facet Joint

The facet joint of the lumbar spine bears a large amount of stress and weight, making them vulnerable to degeneration and injury. Intervertebral foramen which gets formed allows free passage to the spinal nerves. 

Reduction of the size of this foramen, due to degeneration in the disc or joint, compresses on the spinal nerve to get referred pain in the lower leg. 

close-packed position - EXTENSION
resting position - midway between flexion and extension.

capsular pattern - Rotation and Side-flexion equally restricted than Extension and flexion.

to put it simple

FLEXION - FACET OPEN

EXTENSION - FACET CLOSE

Initial Assessment

The Maitland concept is a fantastic tool and widely accepted across the world for approaching an initial assessment as it can be used to form a logical and deduced hypothesis about the nature of the origins of the movement disorder or pain. 

Maitland's concept has a thorough physical examination assessment to conclude the cause of the concept of Pain and Irritability. it also incorporates the Physiological and accessory movement of the vertebral joints. 

combination of Subjective Assessment with objective assessment findings correlate with physical movement and palpation technique to assess individual segment involved.

Maitland Approach:

Active Physiological Movement.

Passive Physiological Movement.

Accessory Movement.

Passive Physiological Movement with Accessory.

HVT (manipulation: high-velocity thrust)

you can also add combined movement and functional movement into your assessment. 

Dysfunction Syndrome: Palpation.

The Lumbar biomechanics work on Fryette's Law. (an osteopath)

Type 1 dysfunction (neutral spine): when the spine is in a Neutral position ( no flexion or extension) side flexion on one side causes the rotation to the other side. (due to the arrangement of the superior and inferior surface of the facet joint. (normal biomechanics) (a group of 2 or more vertebrae)

usually caused by long restrictions. tends to be compensatory curves.

Caused due to repetitive strain, Secondary compensation, rapid stretch, and often misdiagnosed as hypertonicity or spasm in muscular group. 

look for asymmetry in the spinous and transverse process.

Type 2 dysfunction (Flexion and Extension) : when the spine is in a non-neutral position (i.e either in F/E)  side flexion on one side causes the rotation to the same side. (due to the arrangement of the superior and inferior surface of the facet joint. (normal biomechanics)

Dysfunction is predominantly seen in only one segment due to shorts restrictors / Deep muscles (Rotatores, multifidus, intertransversalis, interspinalis) and caused due to external trauma and found only in flexion and extension. 

look for asymmetry in spinous and transverse process on palpation.

• ERS Syndrome (Extension, Rotation and Side flexion)
• FRS Syndrome (Flexion, Rotation, Side flexion) 

are typically type 2 dysfunction. 

Sometimes, bilateral facet motion can get locked open and closed ( i.e locked either in flexion or extension)...in such cases, it is evident through the interspinous process space.

If interspinous process space is less - locked in extension, if more - locked in flexion.

_______________________________________________________________

Derangement Syndrome - Disc pathology.

Dysfunction Syndrome 

• Somatic dysfunction - soft tissue.
• mechanical Dysfunction - facet joint, bones, spinal segment.

Why Does facet spinal motion dysfunction happen

• entrapment of synovial meniscoid or membrane
• altered biomechanics.
• smooth gliding surfaces lost.
• altered biomechanics property of fascia, capsule, ligament, and muscles.
• postural compensation.
• trauma.

How to Assess and treat It

on palpation - on the spinous process and transverse process, check for locking and unlocking mechanism in a neutral and non-neutral position for all lumbar segment. (L5 - L1) 

Neutral/non-neutral position: preferred in prone lying since muscle actions are isolated. 

(sitting/standing are the other options) Extension.

Flexion either in sitting or sit back on the heel position.

Treatment of FRS and ERS Syndrome - Muscle Energy technique (MET) 

combined movement (coupled movement) on examination remain the same or restricted from start is suggestive of facet joint involvement. PAIN increases with repeated movement.

Muscles of Lumbo Sacral Complex

The muscles that support the pelvic girdle as well as the lumbar spine and hips 

The deep posterior longitudinal system consists of the erector spinae, thoracolumbar

fascia, and the hamstring muscles, along with the sacrotuberous ligament.

The superficial posterior oblique system includes the latissimus dorsi, gluteus

Maximus, and the intervening thoracolumbar fascia.

The anterior oblique system consists of the internal and external obliques, the contralateral adductors, and the abdominal fascia in between.

The lateral system consists of gluteus medius and minimus and the contralateral adductors.

The innermost muscle group consists of the multifidus, transverse abdominus, diaphragm 

and pelvic floor muscles that can play a role in stabilizing the pelvis and indirectly the lumbar spine

Form Closure (bones) and Force Closure (muscles + Fascia+ ligament) gives firm stability to SI Joint. 

SI Joint dysfunction is more commonly seen in females, especially during pregnancy as the hormones released, increases the laxity of the ligaments, also increase the weight of the baby result in a significant increase in motion of the SI joint. 

Pain that is caused by sacroiliac joint problems is usually felt when turning in bed,

getting out of bed, or stepping up with the affected leg. 

Often, the pain is constant and unrelated to the position. 

Climbing or descending stairs, walking, standing on one leg and standing from a sitting position, or sitting for long hours, all stress the sacroiliac joint.

SACRUM AXIS

Transverse Axis - Nutation and Counter Nutation

Oblique Axis - Rotation

Vertical Axis - Tilting (Up / Down)

SI Joint can cause localized pain or referred pain. SI Joint is a highly sensitive and irritable structure as it has a rich innervation of the spinal nerves, cauda equina, lumbosacral plexus and sacral nerves. 

Anatomy facts

largest axial joint with average surface area of 17.5 cms square, which allows little mobility but acts as load-bearing and transmission of forces from upper to lower body. 

Causes 

Traumatic - 

• Fall on the buttocks, 
• Motor vehicle accident, 
• heavy lifting with combined movement. 

Atraumatic - 

• postpartum.
• infection.
• lumbar dysfunction.
• scoliosis.
• motor and muscles imbalance.
• ankylosing spondylitis.

High prevalence of SI Joint Pain post-Lumbo Sacral fusion influenced by increased mechanical stress coming from Lumbar Spine. 

presence of meniscoid in SI joint space due to cartilage degeneration, often makes PSIS - the palpatory landmark to show tenderness and localized pain around 2cms. (Fortin Finger Test)

all provocative tests like thrust, compression, and distraction confirming with positive tenderness, history, and physical examination and movement confirm the diagnosis.

SI JOINT INJECTION with lidocaine (1ml) - CONFIRM DIAGNOSTIC TEST for SI dysfunction.

reduction of the symptoms by 80% confirms the Diagnosis.

(to be continued....)