Spine



Scoliosis

Lateral curvature of the spine of 10o or more with associated vertebral rotation (SRS)

 

Incidence

Screening: 1.3 - 1.8 per 1000
Male : Female = 3.5:1 but more females with larger curves (more than20o the ratio goes to1:5)
Male sex is a good prognostic factor
Girls are more commonly affected with 2 - 3% at the age of 16 having a scoliosis more than 10o, 0.5% more than 20o and 0.2 - 0.3% more than 30o

 

Classification

Mobile:
(SRS Non structural) No structural abnormality, vertebrae not rotated and the curve is always reversible
May be
postural
compensatory (eg leg length discrepancy)
sciatic (due to nerve root irritation or compression)
Fixed:
(SRS Structural) Always associated with vertebral rotation and does not disappear with changes in posture (eg bending forward)

Secondary curves develop to compensate for the primary deformity which may also become fixed

 

Aetiology: (Structural)

Idiopathic(accounts for the majority of curves ~ 80%)
Infantile:
Less than 3 years
Male more than Female and ~ 90% are thoracic curves convex to the left
85% resolve spontaneously- these have curves less than 35 deg
15% progress- these have
1. curve more than 35 deg
2. RVAD more than 20 deg
treat those who progress

 

Juvenile:
4 - 9 years of age with similar characteristics to the adolescent group but greater likelihood of progression and the need for operation

 

Adolescent:
Older than 10 years
Most common type with 90% being female
Primary thoracic curves with 90% being convex to the right
Primary lumbar curves are convex to the left in 80% of cases

 

Adult:
spinal curvature existing after termination of skeletal growth or maturity

Osteopathic or congenital

Failure of formation
partial unilateral (wedge vertebra)
complete unilateral (hemivertebra)
fully segmented
semisegmented
unsegmented

 

Failure of segmentation
unilateral ( unilat unsegmented bar)
bilateral ( bloc vertebra)

 

Mixed: Assoc with neural tissue defect
myelomeningocoele
meningocoele
spinal dysraphism eg diastematomyelia

Seldom hereditary, most are sporadic, apparently arising from defects in the foetal development process at the 5th to 7th week
only about 25% are non progressive

Neuropathic

UMN lesion
cerebral palsy
spinocerebellar degeneration Freidrichs ataxia
CMT
Roussy- Levy
syringomyelia
spinal cord tumour
spinal cord trauma
LMN lesion
polio
spinal muscular atrophy-autosomal recessive - loss of ant horn cells

3 types:

  1. Werdnig-Hoffmann- appears before 6/12 poor prognosis
  2. Chronic Werdnig-Hoffman appears 6/12-5yo
  3. Kugelberg-Welander appears bw 2 - 17 yo
    bracing not successful- fuse if curve more than 40 deg

Dysautonomia
Result in long 'C' curve if symmetrical weakness, shorter curves or double major curves if weakness is asymmetrical
Polio usually flexible and CP and Spina bifida usually rigid

Myopathic
Arthrogryposis
muscular dystrophy Duchennes lose ability to walk by ~ 12
once in wheelchair- 50-80% scoliosis curve progressive, bracing poorly tolerated, fuse if more than 35 deg
Limb girdle
Fascioscapulohumeral
congenital hypotonia
Myotonia dystrophica

Mesenchymal Disorders
Marfans
Ehlers Danlos syndrome
Homocystinuria

Metabolic

Rickets
juvenile osteoporosis
Osteogenesis imperfecta

Osteochondrodystrophies
Achondroplasia
spondyloepiphyseal dysplasia
Mucopolysaccharidoses

Neurofibromatosis

Miscellaneous
trauma -#or dislocation ( nonparalytic)
tumour benign or malignant
thoracogenic post thoracoplasty or thoracotomy
hysterical
extra-spinal contractures (eg burns, post empyema)
infection

 

Classification: (King)- idiopathic

ref: King etal The selection of fusion levels in Thoracic Idiopathic Scoliosis JBJS 65A: 1302-1313, 1983
Type I:
'S' shaped curve with both curves crossing the midline and the lumbar curve being of greater magnitude on the standing X-Ray (~13%)
Type II:
'S' shaped curve with the thoracic curve being greater than the lumbar and both still cross the midline (~33%)
Type III:
Thoracic curve in which the lumbar curve does not cross the midline (~33%)
Type IV:
Long thoracic curve with L5 over the sacrum but L4 tilts into the curve (~9%)
Type V:
Double thoracic curve

 

Clinically

History
Deformity usually leads to presentation
Pain no more frequent than back pain in the general population
skin
abnormalities in spine area- hairy spots, lipomas
cafe au lait spots

area of curve
shoulder elevation on concave side ( also breast)
reduced waist on concave side
rib hump on convex side
loin hump on concave side
is curve balanced- plumb line occiput to sacrum

 

Leg length
forward bending
rib hump accentuated ( nonstructural scoliosis abolished )
measure rib hump
in cm or deg from horizontal
in forward bending away from the examiner persistent deviation to one side suggests cord or cauda equina
irritation- need to rule out tumour eg MRI

 

Neurological examination
sensory
motor
reflex
tension signs

 

Other
skin- elasticity
hips
feet
hands - hypermobility
palate high arch in Marfans

Look for associated anomalies in congenital scoliosis (eg, reno-genital 25%, dysraphism 20%, heart deformities, Sprengel's shoulder and Klippel-Feil, absent thumb, anal agenises, tracheo-oesophageal fistula etc

X-Rays
Measurement of curvature (Cobb technique)
Standing XR used for measurement
Select the end vertebrae of the curve ( the most tilted from the horizontal)
A line is drawn along the upper end plate of the upper vertebra and another along the lower end plate of the lower vertebra.
Perpendiculars are erected from these - the angle bw the perpendiculars is the angle of the curve
Once the end vertebra have been established measurement should always be from the same vertebrae- supine and bending films included
When a double curve is present ie 2 structural curves both must be measured - one vertebra will be the end vertebra for one curve and the beginning of the other curve= the transitional vertebra
For measuring flexibility -supine maximum voluntary bending films are good for non paralytic problems when curves are less than 80 deg, traction films for paralytic problems or for curves more than 80
The apex vertebrae is the one with the greatest degree of rotation
The major curve is the largest curve and the one with the greatest degree of rotation
Direction of the curve is determined by its convex side

 

Rissers sign:
Divide the iliac crest into quarters
no ossification of iliac apophysis = Risser 1
complete ossification = Risser 4
fusion with wing = Risser 5
Indicates skeletal maturity and takes about 12 - 18 months to become complete after Risser 1 (complete ossification occurs at about 14 in girls and 16 in boys)

Vertebral ring apophysis on lateral X-Ray of spine in lumbar region is the most reliable index of vertebral maturity

Rib-vertebral angle difference (Mehta)
the difference in the angle the rib meets the spine at the apex of the curve- if the angle is more than 20 deg the curve is likely to progress

 

Other Investigations
CT
MRI
Pulmonary function testing

Natural history

Nilsonne and Lundgren
Long term prognosis in idiopathic scoliosis Acta Orthop Scand 39: 456, 1968

 

113 pts , 50 yr FU
twice expected mortality rate for age
-47% disability pensions (30% for spinal deformity)
- 90% had symptoms of bad back

 

Ponseti and Friedman
Prognosis in Idiopathic Scoliosis JBJS 32A: 381, 1950

 

most curves stable after skeletal maturity

 

thoracic curves
more than 60 deg increase at 1 deg / yr ( av 28 deg at 24 yrs)
less than 60 deg increase at less than 1/2 deg / yr (av 9 deg at 24 yrs)

 

lumbar curves
more than 30 deg increase at 3/4 deg / yr (av 18 deg at 24 yrs)
less than 30 deg did not progress

vital capacity reduced in curve more than 60 deg- early death from resp failure is likely in pts with thoracic curves more than 60 deg

 

Pathogenesis

Genetic factors probably multi factorial
? Growth factors but no change in growth increments and spinal dimensions of vertebral bodies involved in the curve compared to those outside the curve
Electromyographic factors have been implemented but these have been shown to be secondary to the deformity
Ultrastructural changes in multifidus also are secondary to the curve
Biochemical factors with differences in the glycosaminoglycans, Type I and II collagen and acid phosphatase may be primary or secondary

 

Treatment

Idiopathic
Infantile
treat those who progress
  1. Serial casting followed by Milwaukee brace- usually the brace manages the curve successfully for many years. Continue bracing until curve is maximally or permanently corrected or until curve progresses in brace
  2. Instrumentation without fusion when progresses despite all nonop measures - aim to delay fusion until 12 in girls and 14 in boys

Juvenile
different from infantile in that curves do not resolve spontaneously
treat those more than 20 deg and less than 60 deg with Milwaukee brace, need to brace until end of growth. If progressive despite bracing, instrument without fusion eg Harrington rod lengthened or replaced every 6 mths, fuse at 12 in girls , 14 in boys

Adolescent
less than 20 deg no treatment - observe
20-29 deg treat if progresses- Milwaukee brace
30-45 deg treat immed with Milwaukee brace
Curves more than 45 deg are less amenable to treatment with bracing- thus start brace treatment on a trial basis and if have not achieved at least 30% improvement within 6 mths then proceed to surgery. Childen with Risser of 4 prior to treatment are not braced because of their skeletal maturity

 

Bracing

Indications
more than20 deg curve with evidence of at least 5 deg progression
skeletally immature
Risser 3 or less
premenarchal or less than 6 mths post
cooperative pt

 

Contraindications
curves more than45 deg
skeletally mature- Risser 4
poor cosmesis
thoracic hypokyphosis ( brace worsens this)

 

Technique
23/ 24 hrs until skeletal maturity
good fit of brace essential - monitor
monitor with serial XR eack 4-6/12
can use Boston brace for curve with apex T8 or lower
treat until the end of growth ie Risser 4 or full vertical ht
curve maintained less than 35 deg with brace - no need for surgery

 

Weaning from brace
when vertical growth has ceased
wean 1 hr/ day /mth - thus takes 1 yr to wean to night bracing only- the pt should wear the brace at night only for the next year

 

Results
10-15% of curves less than 40 deg at onset of bracing go on to fusion
more than 30 % of curves more than 40 deg at onset of bracing go on to fusion

Surgery for idiopathic scoliosis
consider pt factors and XR measurement

indications
-curve progressing more than 45 deg should have surgery
- curves with thoracic lordosis have poorer resp function and should be corrected earlier
- cosmesis

When 12 girls , 14 boys with fusion
If operate earlier aim to instrument but not fuse
Should fuse the major (structural) curves and ignore the compensatory (secondary) curves
Include in the fusion area all vertebrae rotated in the same direction as the apical vertebra- ie extend to the first neutral vertebra
Stable zone of Harrington- the lower level of fusion should fall within the zone defined by 2 vertical lines drawn up from the lumbosacral facets

King etal - the stable vertebra is that vertebra most closely bisected by a line drawn up from the centre of S1 with the pelvis levelled- fuse to this vertebra

 

Type 1
fuse both curves to the lower vertebra but no lower than L4

 

Type 2
fuse thoracic curve selectively to the stable vertebra

 

Type 3,4
fuse to include the measured thoracic curve with the lower end of fusion the stable vertebra

 

Type 5
fuse both thoracic curves to the stable vertebra

Flattening of the lumbar spine should be avoided at all costs
Generally assess the mobility of the curve with side bending films before and generally avoid long lumbar fusion if possible
Thoracoplasty (excision of 5 or 6 ribs) in patients with a curve of 90o or more resulted in neither an increase morbidity or decrease pulmonary function

 

Osteopathic or congenital

75% of curves will progress , ~ 50% will require treatment
Bracing helpful esp in cases where curve is flexible
main indication is to delay surgery as long as possible
If curve progresses despite orthosis surgery indicated

Surgery
Congenital curves usually require orthotic treatment until sufficient growth has occurred however if despite bracing the curve progresses fusion should be performed regardless of age.
Anterior and posterior fusion is required to prevent non uniform growth (crank-shaft phenomenon)
Never wait until the end of growth to treat operatively, if young can instrument without fusion, lengthen during growth (what they lose in growth they make up for in lengthening the spine)

 

Neuropathic and Myopathic

Hold position until old enough to fuse (after 10 years preferably) as progression is usually continuous and rapid with growth
Molded body jackets used as better tolerated and better pt function than Milwaukee
surgery if curve over 50 deg
Aim to get occiput over S1 and the pelvis level
Luque- often have to fuse from T1-2 to the sacrum

 

Spinal cord monitoring

ref: Forbes etal Spinal cord monitoring in Scoliosis surgery JBJS 73B: 487-491, 1991
SEP magnitude decreases more than 50% signif chance (38%) of neurological damage
no false negatives ie normal SEP trace= normal neurology
conclude that epidural SEP monitoring is more sensitive than the wake up test

 

Complications

Brace:
Superior mesenteric artery occlusion of the third part of the duodenum
Pressure sores

Surgery:
Pseudarthrosis now ~ 2% (lumbar more than thoracic and paralytic more than idiopathic)
Neurological complications ~ 3% with CD increasing up to 17% with some techniques without spinal cord monitoring
Crankshaft phenomenon (anterior growth in the presence of solid posterior tether)
Anterior surgery may result in loss of lumbar lordosis and increased chance of back pain
DVT, PE, infection (1.5%) etc

Wake up test:
Accidental extubation
Air embolus
Violent movement 'popped rod'

 

Prognosis

Probability of a curve progressing is related to the pattern of the curve, the magnitude of the curve, Risser sign, the age at presentation and the menarchal status
Once established the curve is likely to increase during the growing period
Further deterioration in the curve after reaching Risser 4 is slight but curves more than 50o may increase at a rate of 1o per year regardless of maturity
Significant curves in a younger child and higher curves have worse prognosis
Less than 30o most curves are benign and greater than 60o most progress but at variable rates depending on the degree of rotation and location of the curve
Increased vertebral rotation even with low angle scoliosis has increased chance of progression
In adolescence with idiopathic scoliosis whose curves measure less than 30o at skeletal maturity tend not to progress regardless of curve pattern
Progression of curves that are greater than 30o appears to be related to the amount of vertebral rotation with thoracic curves between 50o and 75o progressing most rapidly at about 1o per year
Combined curves tend to balance with age and do not tend to progress unless greater than 60o at cessation of growth
Pain develops in approximately 80% of patients who had an arthrodesis to the fifth lumbar vertebrae in adolescence, 60% of those fused to the fourth, 40% of those to the third and 30% of those to the second lumbar vertebrae.

 

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Kyphosis


Posteriorly directed sagittal plane curvature of the spine (lordosis is anteriorly directed)

Incidence

0.4 - 0.8%
Males ~ Females

Classification

Mobile:
  1. Postural - usually seen in
    adolescents
    women after childbirth
    ligament laxity
  2. Weakness of trunk muscles
    neuromuscular dystrophies
    poliomyelitis
  3. Compensatory
    eg secondary to hip deformity (FFD) and lumbar lordosis
Fixed:
  1. Scheuermann's disease
  2. Congenital
    failure of segmentation
    failure of formation
    mixed
  3. Neuromuscular
    UMN
    MN
    polio
    spinal muscular atrophy
    myelomeningocoele
  4. Post traumatic
    acute / chronic
  5. Inflammatory
    infection
    TB
    pyogenic infection
    noninfective
    Ankylosing spondylitis
    RA
  6. Metabolic
    Osteoporosis
    senile or juvenile
    Osteogenesis imperfecta
  7. Osteochondrodystrophies
    Achondroplasia
    mucopolysaccharidoses
  8. Tumour
    benign
    malignant
    primary or secondary
  9. Post surgery eg laminectomy or irradiation

     

Angular Kyphosis (Kyphos)

a kyphos is always fixed
Congenital (missing or fused vertebrae)
TB
Secondary to fracture
Calves disease (vertebra plana)

 

Age of onset

children: congenital
adolescents: postural or Schuermanns
young adults: ankylosing spondylitis
elderly: osteoporosis, Pagets, Pathological

 

Measurement of Kyphosis and Lordosis

Cobb technique:
standing lat XR
selection of end vertebrae based on the max tilted vertebrae

Flexibility
determined on a hyperextension XR taken supine with a firm bolster under apex of deformity
Normal kyphosis = 20-45 deg in thoracic spine
T1-T5 not well seen on normal lat film- if kyphosis greater than 33 deg T5-T12 this is suspicious of abnormal kyphosis and warrants better quality films of the upper T-spine

 

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Congenital Kyphosis

due to congenitally anomalous vertebrae
2 types:
1. failure of formation of all or part of the vertebral body
2. failure of segmentation of the vertebral bodies anteriorly unsegmented bar
in both progressive deformity occurs due to nongrowth anteriorly and persistent growth posteriorly

Paraplegia:
can result from progressive Kyphotic deformity esp in the T- spine
assoc with type 1, not type 2 deformities
may occur as early as birth or later

 

Treatment

no effect from orthoses
Surgery
- ideally early detection and early posterior fusion (less than 55 deg curve, pt less than 5yo)
fusion can be done as early as 6/12, best results if done less than 3 yo
need to protect fusion with cast for ~ 1 yr to allow it to consolidate
more severe deformity- ie pts over 5 yo with kyphosis greater than 55 deg will require anterior release and fusion as well as posterior fusion ( post fusion done 1 more level above and below the anterior fusion)

 

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Scheuermann's disease

Scheuermann was a Danish radiologist

Definition

excessive thoracic kyphosis ( Cobb angle greater than 45 deg ) with wedging of 5 deg or more of at least 3 adjacent apical vertebrae and vertebral end plate irregularities
20 - 45o of kyphosis is normal in the 15 - 20 year old
SRS has defined less than 20o as abnormal (Hypo-kyphosis)

Incidence

Affects nearly 10% of the population with reports of between 0.4 and 8% of the general population
Only 1% ever seek medical attention during their youth
Male ~ Female

Aetiology

The aetiology of Scheuermann's disease remains unknown
There is however a strong family tendency and enchondral ossification of the vertebral bodies appears to be the abnormal factor contributing to wedging of the bodies
? osteochondritis of the vertebral epiphysis as the epiphyseal plate is irregularly ossified with growth arrest of the anterior vertebral bodies
? traumatic infraction of the end plates in children who out grow their bone strength during the growth spurt
Tightness of the anterior longitudinal ligament of the spine may contribute
? Collagen weakness of vertebral end-plates with a decrease in the collagen to proteoglycan ratio in the matrix of the end-plate

 

Clinically

Starts at about puberty
Become increasingly round shouldered
Seldom painful unless severe deformity develops and usually subsides once growth ceases
May complain of back ache or fatigue especially as they get older (adolescent more likely to complain of thoracic pain and the adult lumbar pain due to compensatory increased lordosis)
Patients with Scheuermann's are generally taller than average
Smooth thoracic kyphosis develops and a mild or moderate scoliosis is evident in about one third of patients
Thoracolumbar Schuermanns: frequently painful and cosmetically unacceptable as the thoracolumbar spine is normally straight
Lumbar Scheuermann's more common in male patients who are competitive athletes and in individuals from rural communities suggesting it is an injury affecting vertebral growth
Most adults who have pain have evidence of moderate or advanced spondylosis on radiographs
X-Rays
The bodies of several adjacent vertebral bodies are wedged and have irregular end-plates (at least 3 vertebrae with wedging of 5o or more, Sorensen)
Schmorl's nodes may be evident (disc herniation through the vertebral end plate)
Epiphyseal plates appear fragmented especially anteriorly
Lateral X-Rays over a bolster at the apex of the curve indicates the structural nature of the curve
Lumbar Scheuermann's is characterised by irregularity of the vertebral end plates, the presence of Schmorls nodes and narrowing of the intervertebral discs without wedging of the vertebral bodies

 

Treatment

Analgesics and anti-inflammatories are useful for painful periods and in patients developing degenerative changes
Work modification and postural exercises are indicated
With kyphosis up to 45 degrees, back strengthening and postural education
Bracing
Milwaukee if significant deformity (greater than 45degrees)and still growing, nearly always results in success (not if curve excessive from the outset of bracing, eg greater than 70% or vertebral wedging)
Usually within 4-6 wks the deformity corrects in the brace if it is flexible - need to maintain correction
Full time bracing for 12 - 18 months then weaning for another yr- monitor during weaning- if any loss of correction resort ot full time brace for further 6 mths
exercise program with bracing to strenghten extensors
Av correction with brace is 40% of curve
Surgery
rare in Schuermanns
indications: Kyphosis greater than 60o in an adult
greater than 75o in an adolescent (bracing not useful )
unacceptable cosmesis
If the kyphosis does not correct to less than 50o on a lateral radiograph over a bolster then combined anterior release and fusion and posterior fusion will be necessary. If does correct to less than 50 deg post fusion sufficient alone.
For fractures a kyphus angle of less than 30o is unlikely to progress
Prognosis:
Sorensen: good prognosis for thoracic Scheuermann's, moderately good or the thoraco-lumbar region and relatively poor in the lumbar region
Skeletally immature patients Risser 4 or lower, posterior fusion alone is adequate and is followed by little loss of correction.
In Risser 5 patients combined anterior and posterior surgery is recommended
if the resultant deformity remains less than 60o most patients will have very little long term difficulties

 

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Childhood Discitis

Menelaus M.B. Discitis JBJS 46B: 16-23, 1964
Wenger etal The spectrum of intervertebral disc space infection in children JBJS 60A:100-108, 1978

 

Definition

a benign disease of unknown aetiology characterised by back pain, disc space narrowing, and resolution of symptoms with rest

 

Incidence

rare
av age 3 yo

 

Aetiology

unknown

 

Clinically

pain, difficulty walking or sitting
may be assoc with fever, malaise
may be preceded by URTI etc
reduced motion, muscle spasm, abnormal posture

 

Investigation
Bloods
ESR usually up
WCC usually normal
Blood cultures - +ve in ~ 50% - after 6 wks of onset of symptoms organisms do not appear to isolated from blood cultures - due to rapid destruction of bacteria once the end plates are breached
Radiology
- early normal
later disc narrowing, progressive end plate lesions with erosion into the vertebral body
latest - fusion rare, usually very little residual disc narrowing
CT
MRI

 

Treatment

Rest - until no pain or limitation of motion, and until ESR normal
antibiotics- indicated if febrile, +ve blood cultures, +ve biopsy, IV until pt comfortable, then oral for 3 more wks

Prognosis
good- spontaneous recovery is almost the rule

 

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