Systemic conditions Flashcards Preview

Spine FRCS > Systemic conditions > Flashcards

Flashcards in Systemic conditions Deck (47):

What is DISH?

  • Diffuse idopathic skeletal hyperostosis


  • A very common disorder
  • Unknown aetiology
  • characterised by presence of non marginal syndesmophytes at 3 successive levels involving 4 contiguous vertebrae


What is DISH aka ?



What is DISH define by?

  • ( different from Ankylosing spondylitis = MARGINAL SYNDESMOPHYTES)


What are syndesmophytes?

  • Vertical outgrowths that extend across the disc space


Where do syndesmophytes  occur?

  • Anywhere in the spine
  • usually THORACIC T7-11 region, > on RIGHT side thought to be due to the protective effect of the pulsatile aorta on the left thoracic spine!!!
  • Symmetrical ( R+L) in CERVICAL and LUMBAR SPINE


What is the epidemiology of difuse idiopathic skeletal hyperostosis?

  • Overall incidence 6-12%
  • uncommon before 50 years
  • less common in africans, asians


  • anywhere in spine
  • most common Thoracic spine - Right side >cervical >lumbar
    • thought due to protective nature of pulsatile aorta on left thoracic spine
    • symmetrical sides in cervical/lumbar


What are the risk factors for developing diffuse idiopathic skeletal hyperostosis?

  • Gout
  • Hyperlipidaemia
  • diabetes


What is DISH associated with?

  • Lumbar spine stenosis
  • Cervical spine
    • hoarness
    • sleep apnoea
    • cervical myelopathy
    • dysphagia and stridor
  • Spine fx and instablity
    • Ankylosis creates long lever arm-> displacement with minimal force
    • hyperextension injuries are common


What are the symptoms and signs of diffuse idopathix skeletal hyperextosis?


  • Often asymptomatic & discovered incidentally
  • thoracic/lumbar spine
    • mild chronic pain
    • stiffness esp in mane
      • aggrevated cold weather
  • cervical
    • pain & stiffness
    • dysphagia
    • stridor
    • hoarness
    • sleep apnoea


What investigaitons are useful in dx of DISH?

  • xrays
    • ap and latera spine
    • non marginal syndesmphytes at 3 successive levels ( 4 continous vertebrae)
    • thoracic syndesmophytes on right side
    • c spine ant bone formation with preservation of disc space ( unlike ank spon)
    • lumbar spine- symmetrical syndesmophytes
    • other joint involvement -elbow
  • Technetium bone scan
    • increased uptake in areas of involvement


Is Diffuse idiopathic skeletal hyperextosis related to HLA-B27?

  • NO associated with HLA-B28 -pt with DISH and DM


what are the radiographic findings of DISH

  • NON MARGINAL SYNDESMOPHYTES at 3 successive levels ( 4 contiguous vertebra)
  • Flowing candlewax
  • preservation of disc space
  • no ostepenia
  • no assoc with HLA- B27
  • age - older middle age
  • No involvement in SI JOINT

cf ankl spon

marginal syndesmophytes, bamboo spine, ossificiation of disc space, osteopenia, strong assoc wiht HLA b27, younger pts, bilateral sacroilitis


What is the tx of someone with Diffuse Idopathic Skeletal Hyperextosis?

non op

  • activity modification. physical therapy, brace wear, NSAIDS, BISPHOSPHONATES
    • most cases


    • for lumbar stenosis, cervical myelopathy, adult spinal deformity


What are the complications of DISH?

  • Mortality
    • C spine trauma in DISH
      • 15% tx operatively
      • 67% tx non operatively
  • Heterotrophic ossification
    • increased risk of HO after THR
    • 30-50% for THR with DISH cf <20% wout


Define ankylosing spondylitis?

A chronic systemic autoimmune spondyloarthropathy characterised by

  • HLA- B27 histocompatablity complex positive
  • RH negative- seronegative
  • primarily affecting spine


What is the pathoanatomy of ankylosing spondylitis?

  • exact mechanism unknown
  • likely autoimmune reaction to an envirnomental pathogen to gentically susceptible individual
  • theories in relation to HLA- B27
    • HLA- B27 aggregates with peptides in joint -> degenerative cascade
  • Enthesitis
    • entheses inflammation -> bony erosions, surrounding soft tissue ossification and joint ankylosis (diff from RA- synovial)
  • Disc space involvement
    • Inflammation of the annulus -> bridging of osteophyte formation- syndemosphyte


What is the epidemiology of ankylosing spondylitis?

  • 4:1 Male : female
  • affects 0.2% caucasians population
  • usually presents at 30 years
    • juvenile form <16 yrs inc enthesitis
    • fewer than 10% HLA-B27 positive pt have symptoms
  • Genetics
    • HLA- B27 on 6th chromosome, B locus
    • genetic predisposition but mode of inheritance is unknown


What are the dx criteria?

  • Bilateral sacroilitis
  • +/- uveitis
  • HLA- B27


What are the systemic manifestations?

  • Acute anterior uveitis/ iritis
  • Heart disease
  • pulmonary fibrosis
  • renal amyloidosis
  • ascending aortic conditions- regurge, stenosis
  • Klebsilella peumoniae synovitis
    • HLA-B27 more susceptible to these


What are the orthopaedic manifestations of ank spon?

  • Bilateral sacroilitis
  • progressive spinal kyphotic deformity
  • cervical spine fractures
  • large joint arthritis


What is enthesis?

  • Insertion of tendon, ligaments or muscle to bone


What are the symptoms of ank spon?

  • Lumbosacral pain and stiffness
    • most pts
    • worse in mane
    • insidious onset 3rd decade
  • Neck and upper thoracic pain
    • late in life
    • acute neck pain- raise suspicion of fracture
  • Sciatic
  • loss of horizontal gaze
  • shortness of breath
    • costovertebral joint involvement-> reduced chest expansion


what are the signs of ank spon?

  • Limited chest wall expansion
    • <2cm more specific dx HLA- B27 
  • Decreased spine motion
    • Schober test- used to elevate stiffness
  • Kyphotic spine deformity
    • chin on chest flexion- see pic
    • caused by multiple microfx over time
    • Chin brow to vertical angle
      • measured on lateral 
      • correction of this angle- improved surgical outcome
  • Hip flexion contraction
    • exam in supine and sitting position helps differentiate sagittal plane imbalance due to hip flexion contractures or kyphotic spinal deformity
  • Sacroiliac provocation test
    • faber test
    • flexion/abduction/ ext rotatation of ipislateral hip causes pain


What imaging is useful in dx ank spon?

  • Xrays spine
    • full length AP, lateral axial spine
    • negative in 50% with spinal Fx
    • Squaring of vertebra with vertical Marginal syndemosphytes- see pic
    • Late vertebral scalloping - bamboo spine
    • measure chin to brow vertical angle
    • xray of pelvis
      • ​ferguson pelvic tilt view
      • xray beam 10-15 degree cephalad-see SI
      • Bilateral symmetrical sacroiliac erosions


  • Will show bony changes but no active inflammation
  • best for dx of Cervical Fx


  • Will detect Inflammation - detect early AS


What is the tx of ank Spon?

Non operative

  • NSAIDS, COX-2 inhibitors and PT
    • first line of tx for pain and stiffness
    • oral steriods not recommended
  • TNF alpha blocking agents
    • 2nd line
    • infliximab, etancerpt, adalimumab
    • improvement in symptoms


  • depends on cervicothoracic fx
  • spinal deformity
  • large joint arthritis


What is the epidemiology of cervicothoracic fractures in AS?

  • Most occur midcervical and cervicothoracic junction
  • Often extension type- involve all 3 columns
  • maybe occult- consider CT scan
  • High mortality rate 2ary to epidural haemorrhage
    • 75% neurologic involvement
    • neurologic symtpoms often present late


What is the tx of cervicothoracic Fx?

Non operative

  • Traction, orthotic, halo immobilisation
    • stable spine fractures with no neurological deficits
    • low weight traction may faciliate reduction


  • Spinal decompression with instrumented fusion
    • Progressive neurological deficit
    • epidural haematoma with neurologic compromise
    • unstable fx pattern
    • decision to go ant vs post depends on Fx level, presence & location of haematoma & osteoporosis
    • Outcomes
      • high rate of complications
      • progressive deformity
      • nonunion
      • hardware failure
      • infection


What are the tx for spinal deformity with AS?

  • Kyphotic deformity
  • elliminate hip conttractures as reason for deformity


  • Lumbar osteotomy
    • thoracolumbar kyphotic deformity
    • goal to restore sagittal balance & horizontal gaze
    • closing wedge (pedicle subtracting) osteotomy
    • hinge located on ant spine
    • greater deformity correction 30-40o per level
    • better fusion & stability due to direct bony apposition
    • Vertebral body resection
      • entire vertebral body resected and replaced by cage
    • Single-level opening wedge osteotomy
      • ​hinge on post edde vertebral body
      • requires rupture of ALL
  • C7-T1 cervicothoracic osteotomy
    • for chin to chest deformity
    • slight under correction with final chin to brow angle 10o
    • adv vertebral art ext to transv foramen, larger canal diameter
    • post op halo immobilisation used as pt poor bone quality


What is the tx for large joint arthritis in AS?

  • Asymmetric involvement of large joints
  • shoulder and hip commonly involved


  • Total hip replacement
    • pt with severe arthritis hip 2ary to AS
    • pts have more VERTICAL/ ANTEVERTED Acetabulum
    • may lead to ANTERIOR DISLOCATIONS after THR
  • Bilateral total hip arthroplasty
    • kyphotic deformity due to hip flexion contracture deformity
    • at risk of dislocation


What is the epidemiology of cervical spondylitis?

  • Present in 90% of pts with Rheumatoid Arthritis
  • Diagnosis often missed
  • included 3 main types
    • Atlantoaxial Subluxation
    • Basiliar Invagination
    • Subaxial Subluxation


What is the classification of Rheumatoid cervical spondylitis?

  • Ranawat

  • Class 1- Pain , no neurologic deficit
  • Class 2- Subjective weakness, hyperreflexia, dyssthesias
  • Class 3A- Objective weakness, long tract signs, ambulatory
  • Class 3B- Objective weakness, long tract signs , non ambulatory


What are the signs and symptoms of rhematoid cervical spondylitis?


  • Similar to cervical myelopathy
  • neck pain
  • neck stiffness
  • occipital headaches
  • gradual onset of weakness and loss of sensation


  • Hyperreflexia
  • upper & lower extremity weakness
  • Ataxia- gait instability/loss of hand dexterity


What imaging is useful in dx of cevical spondylitis?

  • Xrays
    • Flexion-extension
      • obtain before elective surgery
  • CT 
    • better for bone anatomy & surgical planning
  • MRI
    • identify degree of spinal cord compression


What is the general tx of cervical spondylitis?

Non op

  • Pharmacology


  • Spinal decompression and stabilisation
    • goal is to prevent further neuroloigcal progression and surgery may no reverse existing deficit


What is atlantoaxial subluxation?

  • Presents in 50-80% pts with RA
  • most common to have
  • Anterior Subluxation of C1 on C2 ( can have lat/post)


what is the mechanism for atlanoaxial subluxation?

  • A pannus forms between the dens and C1
  • Leads to destruction of Transverse Ligament & Dens


What measurements are used to define stability on lateral extension-flexion views?

  • Atlanto-Dens Interval = ADI
    • instability = >3.5mm of motion between flexion and extension views
    • instability alone is not an indication for surgery
    • > 7mm = alar ligament disruption
    • >10mm associated with increased risk of neurological injury= surgery
  • ​Space available for cord (SAC) & Posterior atanto-dens interval =PADI same thing
    • <14 mm assoc with increaed risk of neurological injury = surgery
    • >13 mm-most important radiological finding that may predict complete neural recovery after decompression surgery


What is the tx of atantoaxial subluxations?

Non operative

  • IN stable atlantoaxial subluxations


  • Posterior C1-2 Fusion
    • if ADI >10mm (even if no neuro)
    • SAC/PADI <14mm (even if no neuro)
    • Progressive myelopathy
    • indication- must be able to reduce C1 onto C2 - no need to remove C2 post arch
    • add transarticular screws avoid use of halo
    • Post op ct to identify location of vertebral arteries
  • Occiput -C2 fusion
    • if atlantoaxial subluxation is combined with basilar invagination
    • resection of C1 post arch required for complete decompression
  • Odontoidectomy
    • rarely indicated
    • used as a secondary proceedure when there is redisual anterior cord compression due to pannus formation that fails to resolve with time following a posterior spinal fusion


What is Basilar invagination?

  • Superior migration of Odontoid
  • Tip of dens migrates above foramen magnum
  • present in 40% RA pts
  • often seen in combination with fixed atlantoaxial subluxation


Describe the mechanism of basilar invagination?

  • Cranial migration of dens from EROSION and BONE loss between occiput and C1/C2


What lines are useful on lateral xray to dx basilar invagination?

  • Ranawat C1-C2 index
  • Most reproducible measurement
  • centre of C2 pedicle to line conecting the anterior & posterior C1 arches
  • normal  men 17mm, women 15mm
  • distance of <13 mm consistent with impaction


What is the tx of basilar invagination?

  • Operative
    • C2 to Occiput fusion
      • for progressive canal migration >5mm
      • neurological compromise
      • cervicomedullary angle <135o on MRI
    • Transoral/ anterior retropharyngeal odontoid resection
      • ​for brainstem compromise


What is the epidemioogy of subaxial subluxation?

  • Present in 20% pt wth RA
  • Often occurs mutiple levels
  • combined upper c spine instability
  • lower spine involvment more common with 
    • steriod use
    • males
    • seropositive RA
    • nodules present


What is the pathophysiology of subaxial subluxation?

  • Pannus formation and soft tissue instability of facet joints and Luschka joints


What is seen of subaxial subluxation on radiographs?

  • Subaxial subluxation of vertebral body of >4mm or 20% = cord compression
  • Cervical height index ( body height/width) <2.0 almost 100% sensitive and specific for predicting neurologic compromise


What are the tx of subaxial subluxation?

  • Operative
    • Posterior fusion & wiring
      • for >4mm subaxial subluxation in intractable pain and neurological symptoms


What are the operative complications are tx a pt with rheuamatoid cervical spondylitis?

  • Failure to improve symptoms
    • outcomes less reliable with Ranawat Grade 3B
  • Pseudoarthrosis
    • 10-20% pseudoarthrosis rate
    • decreased by extension to occiput
  • Adjacent Level degeneration