lumbar imaging and surgery

what diagnostic triage based on

clincal history and examination

is imaging approriate for a patient w/ LBP and no red flags

no

uncecessary imagning

• increasd cost

• not superior in pain, function, QOL

  • potential harms

potential harms of unecasry imaging

• more fear

• more surgeru

• more injections

• more opiods

• more work absence

LBP w/ low-velocity trauma, osteoporosis, elderly individual or chronic steroid use

• x-ray, MRI, CT

subacute or chronic LBP with thoughts of surgery or intervention

MRI

spine trauma where imaging that migth need imaging

• bony or midline tenderness

• neurologicl signs

• intoxication

• major distracting injury

spine trauma imaging

CT

inflammatory back pain

• X ray

• x ray of SI joint

axial spondyloarhtritis

• insidious onset

• night pain

• get better when moving

• stiffness

• young

AP

• frontal plane curvature

• spinous processes

• facet joints

• pedicles

lateral

• spinal “lines”

• vert body heights

• discs spaces

• IV foramina

• facets and Pars

spondylolisthesis

slippage

spondylolyisis

fracture

complete ankylosis

not joint line at SI joint

disc nomenclature

• disc buldge

  • >25% not focal

• annular fissure

• disc herniation

  • < 25% focal

  • protrusion

  • extrusion

  • sequestration

  • location

MRI and pathology

• poor correlation between most degenerative changes and symptoms

• positive correlation

  • large extrusions

  • major neural compromise

intravertebral herniation

schmorl’s node

• sup/inf herniation

• through endplate

degenerative changes in vertebral endplates

• modic type 1

• type 2

• type 3

modic type 1

edema, inflammatory & fibroplastic activty

hypo on T1, hyperintense on T2

modic type 2

• red marrow replaced by yellow marrow

• hyper in T2, less hyperintense or iso on T2

modic type 3

• sclerosis of end-plates

• hypo on T1 and T2

what is the purpose of surgery

• stabilize unstable segments (fractures and slips)

• eliminate painful motion

• cure infections/tumors

• decompress neurologic elements

• realign mal-aligned segments

• restore normal spinal balance to reduce muscular stress and load

absolte indications for surgery

• fracture instability

• neural compression leading to motor weakness

• cauda equina syndrome

• cord compression

• significant progressive deformity

relative indications for surgery

• leg pain due to root compression

• LBP due to slip, IDR or facet disease. All w/ inability to do desired activities

• neurogenic cladification

• malaligned muscular back pain w/ poor adaptation mechanisms

contradindications

• medically, can the patient tolerate the surgery? are there medically ameliorate issues?

• what is the patient’s T score? (osteoporosis)

• does the patient understand the expectations?

• is the patient high risk? (DM type 1, CAD, age, stroke)

• is the intensity of the surgical procedure and recovery greater than the benefits of the expected surgical success?

• for fusion patients, do they smoke or drink alcohol?

lumbar hnp

• motor weakness (except in EHL but not L5)

• pain intolerable

• failure of conservative treatment w/ continued impairment

• coming up on 3-6 months of sx w/o relief

cauda eqina

• surgical emergency

• should be operated within 12 hours of symptom onset

• saddle paraethesia

progress after microdisectomy

• numbness typically fades away within 6 months. the patch of numbness will contract over time

• not unusual that some ache in the leg returns w/ increased function. if the pain draws attention a short course of an oral steriod can be helpful

• if the pain is greater than VAS 5-6, a new MRI could be helpful (serome or recurrent herniation). seroma can be aspirated

• athletes don’t participate in competitive activities fro 8-12 wks

• annular tears decline degenerative discs

continued leg pain after microdiscetectomy

• wrong diagnosis

• wrong level

• recurrent disc HNP

• epidural fibrosis

• seroma/hemotoma

• incomplete decompression

• collapse of foramen at surgical decompression site

• new onset compression at different level

• chronic nerve injury

recurrent disc hernation

• w/ HNP, annulus by definition has tear through all 30 rings

• disc is avascular so tear can’t heal

• same process that induced nucleus to initially desiccate/separate continues

• recorrance risk is 10-15% w/ or w/o surgery

central laminotomy and varants

• central laminectomy

• central laminotomy

• bilateral hemilaminotomy

• lateral reess decompression

• foraminal decompression

• otomy

half removal

-ectomy

full removal

fusion purpose

• join 2 or more vertebra together w/ a living bridge of bone to stop painful motion of disc, facets, eliminate instability or restore alignment due to collapse of the foramen or progressive scoliosis/kphosis

fusion requirements

• must stablize to prevent motion

• must have graft material to induce bone growth

• must have “injured” surfaces to induce healing reaction

oral supplement ant metabolic impedence to fusion

• NSAID (3 mos-inflammatory phase)

• steroids

• blood clotters and thinners (supplements beginnig w/ “G”)

• diabetes, malnutrition and alcoholism

• cigarette smoking

• osteoporosis (Forteo)

benefit of TLIF

• direct decompression of the exiting nerve root

• can decompress the central canal if stenosis is present

• removal of facet to open foramen

• autogenous bone graft from facet

• all performed trhough one posterior incsiion

indications for surgery for Isthmic spondylolisthesis

• progressive slip grade 2 or larger

• back pain-failed RX

• radiculopathy - failed RX

• motor weakness

oblique latersl interbody fusion/XLIF

• lateral approach to the lumbar spine through the abdominal wall

• approach through or anterior to the psoas muscle

• normally needs backup posterior fixation

• femoral nerve caution

lumbar artifical disc replacements

• knee and hips joints are solo joints-replacement covers the entire motion segments

• a motion segmen in the spine contains 3 joints

• if the disc space has collapsed, stretcheing the diminished space to implant an ADR will put alterd forces on the facets

• if the disc fails, removal can be life trheatening due to vena caval adhesions

• metal on plastic causes wear depbris and osteolysis-loosening

• ADRs have no shock absorption capability

• stress concentration of metal endplate on bone endplate can cause overload fractures

interspinous kyphogenic device

• patients w/ central stensis bend forward to reduce canal compression w/ forward flexion

• this device is jammed between the spinous processes and forces flexion (kyphosis) of the motion

• erosion causes pain

coflex interspinous devices

• coflex device designed to be “shock absorption” device

• as you can see this device causes severe kypohis between L3-4 and L4-5 causing a flat back deformity

vertebroplasty

• Poly Methyl-methacrylate injected into fracture cavity, PMMA hardens into a cement space filler

• placed through a pedicle cannula

• cement can extrude through a fracture line or through basivertebral vein to cause canal compression

• may be ok in elderly who have chronic pain after insufficiency fractures don’t heal

Foraminal Collapse

• Full angular collapse with failure of facets and disc and asymmetric collapse of the vertebral segment

• Nerve is crushed by loss of disc height, spur formation and rotary listhesis

• Only way to relieve pain and reconstruct is with TLIF or XLIF

indications for Pars fracture repair

• Painful uni or bilateral fractures

• Failed 3+ months bracing with pain on return to activities

• Recurrent fracture

• Intact disc without significant slip

• No significant degenerative disc

• No severe atrophic fracture ends or significant gap of the ends

• Younger patient

contraindications for surgical repair of pars fracture

• Any significant slip
• Degenerative disc DZ
• Fracture is distracted >3mm or bilaterally atrophic
• age?

Scheuermann’s Kyphosis

• Young male with severe lower thoracic pain and standing fatigue pain
• Failed all conservative care
• Normal kyphosis 20-40 degrees
• Kyphosis= 77 degrees

scoliosis

Chronic pain due to multiple angular collapses

surgical complications revision

Previously called “Failed Spine Surgery Syndrome” (FBSS) or “Post Laminectomy Syndrome” as failure from spine surgery was not uncommon 20 years ago and no one understood why patients had continued pain post-operatively

SI Fusion Implant Malposition

• Overused surgical technique
• Incidence of SI syndrome 3-4% with SI pain
• Need for surgery should be much lower than 2%
• Implant malposition can cause radiculopathy as noted here
• Patient here had new L5 radiculopathy post-op
• Removal of fixation device cured post thigh pain

when to start therapy

• decompression/microdiscs; start 1-2 weeks post-op

• work on “nerve flossing” gently not uncommon to have flair-up radiculopathy delayed 12-24 hrs

• motor strengthening in the face of neurological weakness

• no EMS w/ first 3 months-neurological weakness

• isometric strengthening is best for 1st 4-6 wks

• avoid the dreaded Bend, load, twist

when to start therapy for fusion

• start therapy 6 wks post-op

• fusion mass is quite soft at this point - heavy troque in therapy could losen hardware

• no bend, load, twist for 3 months

• cardio conditioning and isometrics

• start Full ROM at 3 months

red flags in recovery

• incision drainage, redness, significant tenderness

• constitutional signs (fever, chills, lethargy)

• progressive SLR - increased leg pain/weakness

• increased lower back pain/spasm (infection)

• ileus; swollen belly, reduced bowel sounds (discitis)

• swollen foot/+ Homan’s sign (DVT)

• SOB/chest pain (PE, Pneumonia)