Review of osteoporosis conditions affecting the spine.

1. The Osteoporotic Spine
Richard C. Rooney, MD, FACS
www.seattlespinegroup.com

2. What is Osteoporosis?
• Term used for diseases of diverse
etiology that cause a reduction in the
mass of bone per unit volume

3. What is Osteoporosis?
• Term used for diseases of diverse
etiology that cause a reduction in the
mass of bone per unit volume
• Osteomalacia – in which mineralization
of the organic matrix is defective

5. reduction in the mass of bone per unit volume

6. Classification of Osteoporosis
1. Common forms unassociated with other diseases
1. Idiopathic (juvenile and adult)
2. Type 1
3. Type 2
2. Conditions in which osteoporosis is a common feature
1. Hypogonadism
2. Hyperadrenocorticism
3. Thyrotoxicosis
4. Malabsorption
5. Scurvy
6. Calcium deficiency
7. Immobilization
8. Chronic heparin administration
9. Systemic mastocytosis
10. Adult hypophosphatasia
3. As a feature of heritable disorders of connective tissue
1. Osteogenesis imperfecta
2. Homocystinuria
3. Ehlers-Danlos syndrome
4. Marfan’s syndrome
4. Disorders in which osteoporosis is associated but pathogenesis not understood
1. Rheumatoid arthritis
2. Malnutrition
3. Alchoholism
4. Epilepsy
5. Diabetes mellitus
6. COPD
7. Menkes’ syndrome
Harrison’s Principles of Internal Medicine

7. The Problem
• Ten million Americans (80% women and 20% men)
have osteoporosis
• Estimated that 44 million more have low bone mass
and at risk for developing osteoporosis.
• ½ women and ¼ men over age 50 will have an
osteoporosis-related fracture in their lifetime.
» National Osteoporosis Foundation

8. The Problem
• Causes more than 1.5 million fractures
each year in the U.S.

9. Wrist Fractures:
200,000+
Hip Fractures:
300,000+
Vertebral Fractures:
700,000+
Other Fractures:
300,000+
Source: National Osteoporosis Foundation, 2000
1.5 Million Fractures Annually1.5 Million Fractures Annually

10. The Problem
• 150,000 hospitalizations per year for
the medical management of spinal
fractures.
• Vertebral fractures accounted for over
400,000 total hospital days and
generated charges in excess of $500
million.
» Gehlbach, Osteoporosis Int ‘03

11. The Problem
• In 2002, U.S. economic cost to care for
osteoporotic fractures (hospital and nursing home
direct expenditures)
– more than $18 billion
– daily cost of $49 million
• The 2030 projected cost
– more than $60 billion
– $164 million daily
» National Osteoporosis Foundation

12. Physiology
• Osteoclasts
– Large (20-100μm), multinucleated
– Derived from pluripotential cells similar to
macrophages
– Differ from macrophages – production of
tartrate-resistant acid phosphatase
– Inactive or ‘resting’ until stimulated by
RANK ligand (RANKL)

13. Physiology
• The control of the osteoclast as well as
bone homeostasis is very complex
involving
– Mechanical factors
– Immunological factors
– Hormonal factors
– Neurological factors
– Metabolic factors

15. • Activated cells bind to bone through cell attachment
proteins called integrins
• Cell becomes polarized, ‘ruffled border’ appears in
sealed zone
• pH lowered by production of H ions from the carbonic
anhydrase system which dissolves HA crystals and
removes organic matrix through proteolytic digestion

17. MSP
Leukotrienes
IL-1 HGF
IL-6 PTH/PTHrP
TNF Vitamin D
TGFβ Glucocorticoids
Endothelins Prostaglandins
IL-4 Calcitonin
IL-8 Estrogen
MIP-1α
Glucocorticoids
M-CSF Prostaglandins
Endothelins Calcium
HGF PhosphateIL-4
IL-13
Estrogen
STIMULATION INHIBITION
O-Blast O-Clast

18. MSP
Leukotrienes
IL-1 HGF
IL-6 PTH/PTHrP
TNF Vitamin D
TGFβ Glucocorticoids
Endothelins Prostaglandins
IL-4 Calcitonin
IL-8 Estrogen
MIP-1α Glucocorticoids
M-CSF Prostaglandins
Endothelins Calcium
HGF PhosphateIL-4
IL-13
Estrogen
STIMULATION INHIBITION
O-Blast O-Clast

19. MSP
Leukotrienes
IL-1 HGF
IL-6 PTH/PTHrP
TNF Vitamin D
TGFβ Glucocorticoids
Endothelins Prostaglandins
IL-4 Calcitonin
IL-8 Estrogen
MIP-1α Glucocorticoids
M-CSF Prostaglandins
Endothelins Calcium
HGF PhosphateIL-4
IL-13
Estrogen
STIMULATION INHIBITION
O-Blast O-Clast

20. Pathophysiology
• Estrogen deficient
• Mechanical
• Tobacco
• Steroids

21. Pathophysiology
• Cancellous bone remodeled at 30%/yr
and cortical bone 3%/yr
– Surface area phenomena
• Women lose spinal bone at 2-4%/yr
immediately after menopause

22. Tobacco and osteoporosis
• Impaired osteoblast metabolism
– Breakdown products are toxic to O-blasts through
DNA, RNA, and protein synthesis and toxic free
radical injury
– Free radicals cause cellular membrane injury via
lipid peroxidation
» Fang, Bone ’91
» Galante, Clin Physiol Biochem ’93
» Ramp, Proc Soc Exp Biol Med ‘91

23. Tobacco and osteoporosis
• Protective effects of estrogen negated
– Hepatic metabolism and hydroxy
inactivation of estrogen accelerated
– In women, early menopause and
resistance to exogenous hormone
replacement is common
» Jensen, NEJM ’85
» Michnovicz, NEJM ’86
» Hopper, NEJM ‘94

24. Tobacco and osteoporosis
• Induces calcitonin resistance
» Hollo, JAMA ‘77

25. Mechanical loading physiology

26. Steroid induced
osteoporosis
• Most common cause of drug-induced
osteoporosis
∀⇓ calcium absorption from gut
∀⇑ urinary calcium excretion
• Abundant callus at endplates of
collapsed vertebrae is a strong indicator
of corticosteroid-induced osteoporosis
» Adachi, Am J Med Sci ’97
» Boulos, Ann of Long-Term Care ‘03

27. Steroid induced
osteoporosis
• Bone loss begins immediately and greatest in the first
year (average of 5% loss)
• Significant trabecular bone loss with doses of prednisone
(including inhaled) greater than 7.5 mg per day
» Adachi, Am J Med Sci ’97
• Increased risk of vertebral and hip fractures even with
doses equivalent to 2.5-7.5 mg
» van Staa, J Bone Min Res‘00

28. Steroid induced
osteoporosis
• 30-50% of patients who undergo
corticosteroid therapy sustain fractures
• Fracture risk up to 15% in first year of
treatment
» Adachi, Am J Med Sci ’97
» Cohen, Proc AC Rheum ’02
» van Staa, J Bone Min Res ‘00
» Boulos, Ann of Long-Term Care ‘03

29. Steroid induced
osteoporosis
• Corticosteroids raise the fracture risk up
to six-fold across all ages, regardless of
bone mass prior to steroid treatment
• Calcium and vit D should be offered to
all patients receiving glucocorticoids
» Adachi, Am J Med Sci ’97
» Cohen, Proc AC Rheum ’02
» van Staa, J Bone Min Res ‘00
» Boulos, Ann of Long-Term Care ‘03

30. Bone Mineral Density
• Close correlation between low bone
mineral density and increased fracture
risk
» Hochberg, Arth Rheum, 42: 1246-54, 1999
» Nevitt, Bone 25: 613-619, 1999
• Close correlation between increased
bone turnover and increased fracture
risk
» Adachi, Calc Tissue Int59 Suppl 1: 16-19, 1996

31. Bone Mineral Density
• 1 standard deviation drop
(10%) in BMD is
associated with a doubling
of the fracture risk
» Cummings, Lancet 341: 72-
5, 1993
» Huang, J Bone Min Res 13:
107-13, 1998

32. Pathophysiology
• Type 1
– Post menopausal women
– Enhanced osteoclastic resorption
– High turnover
– C and N terminal collagen crosslink
degradation products
• N-telopeptide and pyridinoline
– Treat with antiresorptive agents
• Estrogen, raloxifene, calcitonin, bisphosphonates

33. Pathophysiology
• Type 2
– >70 years (senile)
– Low turnover
– Osteoblastic deficiency
– Decreased alkaline phosphatase
– Low collagen crosslink products
– Tx with parathormone analog, Ca, vit D

34. Ethnicity & Osteoporosis
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of
Health, Department of Health and Human Services
• Hispanic women at highest
risk
• 10% of Hispanic women over
50 have osteoporosis now
• 49% are estimated to have
low bone mass, putting them
at risk for the disease

35. Ethnicity & Osteoporosis
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of
Health, Department of Health and Human Services
• Hispanic women
get less calcium
than RDA
• Twice as likely to
develop diabetes
• Rate of hip fractures
on the rise

36. Ethnicity & Osteoporosis
Caucasian and Asian-American Women also
at high risk
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes
of Health, Department of Health and Human Services

37. Ethnicity & Osteoporosis
• African-American
women get 50% of
RDA of calcium
• Lupus and sickle-
cell anemia can
raise osteoporosis risk
Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases, National
Institutes of Health, Department of Health and Human Services

38. Ethnicity & Osteoporosis
• Osteoporosis undertreated
in African-American women
• Risk doubles every 7 years
• African-American women
more likely to die from hip
fractures
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of
Health, Department of Health and Human Services

39. Underdiagnosed
Unrecognized
Underreported
Inadequately researched
Men & Osteoporosis
39

40. Men & Osteoporosis
• 2 million American men suffer from
Osteoporosis
• Millions more are at risk
• 80,00 hip fractures each year
• One-third die one year after
fracture
Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases, National
Institutes of Health, Department of Health and Human Services

41. • WHO definition
– DXA
• 1-2.5 sd below mean – osteopenia
• > 2.5 sd below mean – osteoporosis

43. • T-score compares bone density to
the optimal peak bone density for
same gender
– T-score of greater than -1 is considered
normal
– T-score of -1 to -2.5 is considered
osteopenia, and a risk for developing
osteoporosis
– T-score of less than -2.5 is diagnostic of
osteoporosis
• Z-score - compare results to others
of same age, weight, ethnicity, and
gender
– Z-score of less than -1.5 raises concern
of factors other than aging as
contributing to osteoporosis
• factors include thyroid abnormalities,
malnutrition, medication interactions,
tobacco use, and others.

44. Fracture Risk Factors
• 75% for all caucasian women > 75 years
• One OCF = 5-fold risk for another
• Low body weight, recent weight loss,
family hx of fx, smoking, age
» Kaufmann, AAOS bulletin ‘99

45. Compression Fractures
• Osteoporotic compression fracture risk stratification
Risk factor
Amount increase
(fold)
Two or more osteoporotic
compression fractures
12
BMD 2 SD below normal 4-6
Family history of vertebral
fracture
2.7
Premature menopause 1.6
Smoking history 1.2
Melton ’97, Ross ’91

46. Why bother treating this?
Morbidity
• Acute and chronic debilitating pain
• Altered spinal configuration leads to
reduction of motion and strength
• Significant performance impairments in
physical, functional, and psychosocial
domains in older women
» Gold. The Downward Spiral of Vertebral Osteoporosis:
Consequences, June 2003.
» Nevitt, Annals Int Med ’98
» Lyles, Am J. Med ‘93

47. Why bother treating this?
Morbidity
• Decreased pulmonary function and
increased lung disorders
• Increased incidence of sleep disorders
• Decreased appetite and potential for
malnutrition due to stomach
compression
» Silverman, Bone ‘92
» Gold, Bone ‘96

48. Why bother treating this?
Morbidity
• Clinical anxiety and/or depression
• Loss of self-esteem and compromised
social roles
• Increased dependence on family and
friends
» Silverman, Bone ‘92
» Gold, Bone ‘96
» Kado, Arch Intern Med ‘99

49. Why bother treating this?
Mortality
• 23% increased mortality rate compared
to women without spinal fractures
(women ≥ 65 and ≥ 1 spinal fracture)
• 2-3 times more likely to die of
pulmonary causes than those without
fractures
» Kado, Arch Intern Med ‘99

50. Even worse than hip fractures
• 9-fold increase in the relative risk of
dying following a spinal fracture
• 7-fold increase following a hip fracture
– compared to women without any fractures
» Cauley. Risk of Mortality Following Clinical
Fractures, Osteoporosis Int, 2000;11:556-61.

51. Mortality after vertebral
compression fracture in Medicare
population
• 1997-2004, 5% sample
• 97,142 patients
• 53.9%, 30.9%, and 10.5% survival rates
at 3, 5, and 7 years
• Significantly and consistently lower than
controls (age, gender, race matched)
» Lau, JBJS 90: 1479-86, 2008

52. Diagnosis
• Medical history
• Physical exam
• X-rays
• Bone densitometry
52

53. Bone Densitometry

54. Who should have
Bone Densitometry?
• Anyone with a fragility fracture
• All women age 65 and older
• Postmenopausal women younger than
65 with risk factors
• Men over 50 with risk factors

55. Treatment

56. Medication
• Bisphosphonates
• Estrogen Replacement Therapy
• Medications made from natural hormones
• SERMs (Selective Estrogen Receptor
Modulators)

57. Vitamin D metabolites
Parathyroid hormone
New bisphosphonates
New SERMs
Medication-Under Investigation

58. Treatment
• Appropriate
treatment of
fragility fractures
• Surgery if
necessary

59. Prevention
Calcium and Vitamin D Intake
• Adults: 1000-1200 Units per day
• 200-600 IU vitamin D per day

60. Prevention

61. Moderate exercise 3-4 times per week

62. 10-20 Year Olds
Prevention

63. Prevention
20-35 Year Olds
Calcium rich diet and a regular, moderate exercise program

64. Prevention
35-50 Year Olds
calcium-rich diet and regular exercise, consider bone density screening

65. Prevention
Over 50
postmenopausal women may be lose bone mass at a rate of 1 to 6 percent per year
calcium-rich diet and a healthy lifestyle that includes exercise of at least 20 minutes at least 3 times per week

66. OCF Treatment and
prevention
• Bisphosphonates
– Alendronate (Fosamax)
– Ibandronate (Boniva)
– Risedronate (Actonel)
• Calcitonin (Miacalcin,
Calcimar, Fortical)
• PTH – teriparatide
(Forteo)
• SERM –raloxifene
(Evista)

67. Intervention
Relative risk reduction
Vertebral fx
Relative risk
reduction
Non-vert fx
Vitamin D .37 .23
Alendronate (5-40 mg) .48 .13-.49
Etidronate (400mg) .37 .01
Risedronate .36 .27
Calcitonin .21 .20
Raloxifene .40 .09
HRT .34 .13
Flouride .33 -.46
Calcium .23 .14
Guyat, Endocrin Rev 23: 570-578, 2002

68. Medication for Tx and prevention
of OCF
• Bisphosphonates
– Alendronate (Fosamax)
• 35-70 mg/wk
– Ibandronate (Boniva)
• 150 mg/month
– Risedronate (Actonel)
• 35 mg/wk

70. Bisphosphonates
• Most effective inhibitors of bone
resorption
• Most dramatic effect is reduction of risk
of multiple spinal fractures (up to 84%)
• Effects may be estimated by measuring
C-terminal and N-terminal collagen
degradation products
» Levis, J Am Ger Soc 50: 409-15, 2002
» Rodian, JBJS 85-A: 8-12, 2003

71. Bisphosphonates
• Bound to mineral exposed by the
osteoclast
• Osteoclasts resorb bone and
associated bisphosphonate
• Remaining bisphosphonate
subsequently covered until future bone
resorption

72. Bisphosphonates
• Morphologic response of osteoclast to
the nitrogen containing bisphosphonate
is disappearance of the ruffled border
» Sato, J Clin Inves 88, 2095-105, 1991

74. N containing bisphosphonates
alendronate and risedronate
• Directly inhibit farnesyl diphosphate
synthase
– Disrupting geranylgeranyl diphosphate
production
• GGPP tethers proteins to cell membranes integral
to cellular shape and ruffled border formation
» Bergstrom, Arch Biochem Biophy 373: 231-4, 1999
» Van Beek, Biochem Biophys Res Com 264: 108-11, 1999

77. Medication for Tx and prevention
of OCF
• Calcitonin (Miacalcin, Calcimar,
Fortical)
– Injection 50-100 IU/d
– Nasal spray 200 IU/d
• Acute fracture pain treatment also
– Efficacy diminishes after 12-18 months

78. Medication for Tx and prevention
of OCF
• Parathyroid hormone
– teriparatide (Forteo)
• Daily injection for up to 24 months
– Anabolic effect initially with subsequent
osteoclastic recruitment
• Effects may improved with intermittant dosing
with bisphosphonates

79. Medication for Tx and prevention
of OCF
• Selective estrogen receptor modulators
– raloxifene (Evista)
• 60 mg/d

80. How do they get
fractures?
• Minor/ Low energy
–picking up grocery bag
–sneeze
–minor fall

81. Clinical Presentation
• Back pain
• Focal kyphosis
• Loss of height
• Localized tenderness
• Fingertips to lower thigh or knee
suggest OCF
» Glaser, Spine ‘97

83. Radiography
• Xrays
• Bone Scan
• MRI
– Delineating benign and malignant
– Acute vs chronic

84. Plain Radiographs
• Marker at max pain site
• Cobb angle
• Fracture pattern
• Limitations: poor judge of
acuity

85. Bone Scan
• Excellent predictive value
for response to vertebral
augmentation
• DRAWBACKS: poor
detail, det. Level
• Best in conjunction with
CT in pts MRI not feasible

86. Advanced imaging
MRI (preferred)
T1 STIR

88. Eastell, J Bone Min Res ‘91

89. Classification
•Concave and dented – good prognosis
•Sugita, J Spi Dis Tech ‘05

90. Imaging Characteristics
Benign vs Malignant
• Malignant characteristics
– Convex posterior vertebral wall
– Destruction of endplate
– Posterior element involvement
– Soft tissue mass
» Rupp, Spine ’95
» Uetani, Clin Rad ‘04

91. Imaging Characteristics
Acute vs chronic
• Edema
• Sclerosis
• Intravertebral clefts
– Dynamic fracture mobility

92. Clinical Management
Non operative
• Relatively benign course
• Predictable pain improvement over 6-8 wks
• 1500 mg calcium
• 400 IU vit D
• Serum testosterone for men
• Elevated alk phos - suspect osteomalacia
» Lane CORR ‘00

93. Clinical Management
Non operative
• Bracing poorly tolerated and its efficacy
has not been established
• 30% don’t respond to nonoperative
therapy
» Wasnich, Bone ’96
» Melton, Am J Epidemiology ‘89

94. Clinical Management
Operative
• Vertebral body
augmentation
–Kyphoplasty
–Vertebroplasty
• Spinal reconstruction

95. Vertebroplasty/Kyphoplasty
• Postural reduction - prone
positioning
• Augmentation of vertebral body with
PMMA through cannula
• Kyphoplasty adds balloon tamp
reduction step
–Allows low pressure PMMA application

96. Contraindications
• Infections
• Coagulopathy
• Unstable fractures
• Retropulsion of fragments into canal
• > 2/3 collapse may be technically
impossible = relative contraindication
» Cotton, Radiographics ’98
» Cortet, J Rheum ’99
» Amar, Neurosurgery ‘01

97. Vertebroplasty

100. STEP 1
Jamshidi
Needle

101. STEP 2
Guidewire exchange

102. STEP 3
Direct drill bit

103. PMMA injection

105. Kyphoplasty
Balloon is unique to kyphoplasty and
distinguishes from vertebroplasty

106. 1) Normal Vertebra
Normal Vertebra
2) Fractured Vertebra
Spinal Fracture, also known as Vertebral
Compression Fracture (VCF)
3) IBT Insert
Through two small incisions, the doctor
creates narrow pathways into the
fractured bone and inserts two KyphX®
balloons.
4) IBT Inflated
The balloons are carefully inflated in an
attempt to raise the collapsed vertebra
and return it to its normal position. The
balloons are then deflated and removed,
leaving a cavity within the bone.
5) Filling the Cavity
The cavity is filled with a bone cement to
support the surrounding bone and prevent
further collapse.
6) Internal Cast
The cement forms an internal cast
that holds the vertebra in
place.

108. Two-Level
Procedures

109. Multi-Level
Procedures

110. Mechanics of
Vertebral
Augmentation

111. Vertebroplasty/Kyphoplasty
Biomechanics
• Amount of PMMA weakly correlates
with strength and stiffness
» Molloy, Spine ’03
» Kim, The Spine J ‘06
• Location of cement does not effect
loading behavior of bone
» Higgins, Spine ’03
• Stiffness equal with CaPO4 and PMMA
» Tomita, J Ortho Sci ’03

112. Outcomes

113. Clinical Outcomes
Kypho/vertebroplasty vs nonop
• Vertebral augmentation (kyphoplasty or
vertebroplasty) vs non operative care
– Significant pain level and functionality
improvement
» Grados, Rheumatology ’00
» Taylor, Spine ’06
» Kaufmann, Am J Neuroradil ’01
» Zoarski, J Vasc Inter Rad ’02
» Garfin, Spine ’01
» Lieberman, Spine 01

114. Clinical Outcomes
Kyphoplasty vs Vertebroplasty
• Deformity/Ht loss
• Low pressure injection
• Less cement extrusion?
• Equivalent pain relief

115. Clinical Outcomes
Kyphoplasty vs Vertebroplasty
• Biomechanical and Clinical studies
• Equal restoration of height,
strength, stiffness in cadaveric
model between kyphoplasty,
vertebroplasty, cavity creation
system, osteoplasty
» McCann, Spine ‘06

116. Clinical Outcomes
Kyphoplasty vs Vertebroplasty
• Immediate pain relief equal
• Slightly higher risk of extrusion with
vertebroplasty due to lower viscosity
• Slight advantage with improving height
in kyphoplasty
• Insignificant clinical difference
» Phillips, Spine ’02
» Grohs, J Spin Dis Tech ‘05

117. Clinical Outcomes
Kyphoplasty vs Vertebroplasty
• Immediate pain relief equal
• Slightly higher risk of extrusion with
vertebroplasty due to lower viscosity
• Slight advantage with improving height
in kyphoplasty
• Insignificant clinical difference
» Phillips, Spine ’02
» Grohs, J Spin Dis Tech ‘05

118. Fracture Age and Ability to Reduce
• Kushwaha and Lalibert, NASS 2002
– Looked at fracture reduction ability
• acute (<1 mo.)
• sub-acute (1-3 mo.)
• established (3-6 mo.)
• chronic (>6 mo.)
• Time since initial fracture alone does not
predict ability of balloon to reduce
• MRI reveals local edema and acute
component of fracture

119. Fracture Age and Ability to
Reduce
• 75% of chronic fractures can be
expanded
» Crandall, The Spine J ’04
• 50% >8 weeks expandable but earlier
better
» Chin, Neurosurgery ’06

122. Postural reduction

123. 8 mos
3 mos

124. Complications
• Rare
• Leakage
–More common in vertebroplasty
–Cement extrudes into disc space,
canal, basivertebral vein or
embolizes
» Taylor, Spine ‘06

125. Adjacent Fracture
• 5-25 x increased risk of fracture
after 1st
fracture
» Trumees, Spine J ’04
• 10% risk of fracture within 90 days
after kypho/vertebroplasty
» Grados, Rheum ’00
» Lavelle, Spine J ‘06

126. Cancer and spinal fractures
• Insufficiency fractures
• Bone metastasis
• Multiple myeloma

127. Insufficiency Fractures
metastasis
• 17-50% of patients with breast carcinoma and
bone metastasis will experience new spinal
fractures each year
» Body, Cancer ‘03
• Up to two-thirds of patients with bone
metastasis experience severe pain and
disability
» Janjan, Sem Onc ‘01
• Up to 41% of patients receiving radiation to
treat bone metastasis experience bone
fractures
» Patel, Orthopedics ‘01

128. Insufficiency Fractures
multiple myeloma
• 15-30% of patients with multiple myeloma sustain
new spinal fractures annually
• Approximately 75% of patients with multiple myeloma
have bone pain at the time of diagnosis
• 50% of myeloma patients with bone pain in the back
have vertebral fractures
» Body, Cancer ‘03

129. Outcomes
augmentaion with vertebral
tumors
• Outcome and complication profile
similar to non tumor patients
» Alvarez, Eur Spine J ’03
» Fourney, J Neurosurgery ’03
» Martin, Radiology ‘03

131. Less Common: Burst Fracture
• T-L junction
• Posterior VB involved
• +/- neuro deficit
• Treatment distinct
from Compression
Fractures

132. Open surgery
• Neurological deficit
• Risky
• Difficult
• Complicated by
comorbidities
• Fixation issues

133. Indications for reconstruction in
osteoporosis
• Neurological deficit
– Very rare
» Lee, CORR 323: 91-7, 1996
• Painful fractures not amenable to
kypho/vertebroplasty
• Progressive deformity with intractable
pain

134. Indications for reconstruction in
osteoporosis
• When surgery indicated the plan must be
individualized
• Understand co-morbidities
• Spine surgery principles apply with some
exceptions
– Anterior approach with diaphragmatic
manipulation is poorly tolerated in geriatric
patients
– Fixation is problematic

135. Osteoporotic fixation
• Pedicle screws most sound
• Wires and hooks can be used in
conjunction with screws
• Insertional torque directly correlates
with pullout strength
» Multiple authors
• Minimal bone mineral density unknown

137. Osteoporotic fixation
• Although insertional torque important,
oversizing the screws too much places
the pedicle at risk for fracture
• 40% fracture rate when screw diameter
greater than 70% of outer pedicle
diameter
» Hirano, J Spin Dis 11: 493-7, 1998

138. Osteoporotic fixation
• Pullout resistance
– Proportional to insertional torque and BMD
Ryken ’95, Peiffer ’96, ’97, Hitchon ‘03
– Proportional to volume of bone between threads
Chapman ‘96
– Thread depth and outer diameter most important
– Conical screws with constant major diameter
Abshire ’01, Choi ‘02
– Triangulation
Ruland ’91, Suzuki ’01, Huang ‘03

140. Osteoporotic fixation
Critical Insertional Torque?
4 in/lbs
Zdeblick ‘93
Critical BMD?
.7g/cm2
Ito ‘02
.22 g/cm2
Knöller ‘05
.45 g/cm2
Lim ‘95
.674 g/cm2
Bühler ‘98

141. Pull out strength

142. Osteoporotic fixation adjuncts
Expandable screws
– Up to 50% increase in pullout strength
» Cook, J Spin Dis 13: 230-236, 2000
• PMMA
– Up to 500% increase with 2 cc
» Kostuik, unpublished data
• CaSO4
– 68% improvement
» Lotz, Spine 22: 2716-2723, 1997

146. Osteoporosis poses other
problems
• Often coincides with spondylosis
– Combination of a stiff weak spine can be
disastrous
• Odontoid fractures very difficult to
manage
• HALO fixation challenging
• Anterior cervical fixation challenging

148. Conclusion
• Avoidance is key
• Low threshold to investigate bone
density
• Treatment as needed
• Anticipate fixation problems

153. Posterior lateral decompression

159. Thank you
rrooney@seattlespinegroup.com