The Role of Cement Augmentation in the Prevention of Spinal Insufficiency Fractures. Spinal Vertebral fractures and percutaneous cement augmentation, vertebroplasty and kyphoplasty. The arguments for a role in preventing new spinal fractures and those against it. The flaws in experimental biomechanical studies and the importance of clinical spinal stability. Biplanar bipedicular percutaneous imaging approaches and formal trainig schemes to be established to train new practitioners with a biomechanically based cement placement.
The role of Cement Augmentation in the Prevention of Spinal Insufficiency Fractures
1. Dr W J Rennie MSc,FRCR
Musculoskeletal Radiologist
Honorary Senior Lecturer
Leicester Royal Infirmary
winston.rennie@uhl-tr.nhs.uk
The role of Cement
Augmentation in the
Prevention of Spinal
Insufficiency Fractures
2.
3. –Albert Einstein
“Not all questions that can be answered are
worth asking and not all questions that are
worth asking can be answered
4. Acknowledge
Dr B Georgy- San Diego
Prof P Munk- Vancouver
Mr A Qureshi- PhD Orthopaedics
Dr R Botchu Msk Rad
5. Layout
• Thoughts
• Current Literature
• Review Spinal Biomechanics- Fracture
• My Experience
• Cases
• Summary
6. Surgical Procedures with No treatment
Effect Vs Conservative Management
Level 1 Evidence
• Scaphoid waist fracture fixation
• Surgical repair - Achilles Tendon ruptures
• Major limb Fracture fixation
8. Literature Search
• ‘Osteoporosis’, ‘Prophylactic’, ‘cement’, ‘fracture
prevention’
• Recent articles 2009- 2014
• 7 relevant articles Pubmed
• Only 3 on Spine
9. Prophylactic Femoroplasty
• Fracture prevention by
femoroplasty--cement
augmentation of the proximal
femur. Beckmann J et al. J
Orthop Res. 2011
Nov;29(11):1753-8.
• Limited V-shaped cement
augmentation of the proximal
femur to prevent secondary hip
fractures. Fliri L et al.
Biomater Appl. 2013
Jul;28(1):136-43.
10. Literature Against
• The effect of cement augmentation on the load
transfer in an osteoporotic functional spinal unit: finite-
element analysis.Polikeit A, Nolte LP, Ferguson SJ.
Spine (Phila Pa 1976). 2003 May 15;28(10):991-6.
• Material changes in osteoporotic human cancellous
bone following infiltration with acrylic bone cement for
a vertebral cement augmentation. Baroud G, Nemes
J, Ferguson SJ, Steffen T. Comput Methods
Biomech Biomed Engin. 2003 Apr;6(2):133-9.
11. FEA Cement Augmentation
Vertebroplasty: Patient and treatment variations studied through parametric computational models.
Wijayathunga VN et al. Clin Biomech (Bristol, Avon). 2013 Oct;28(8):860-5.
12. –White AA, Panjabi MM. Clinical biomechanics of spine.
Abnormal flexion-extension mobility - Paradoxical motion.
Kinematics of Spine Chap. 2; 89.
Concept of stability
“Spine is stable when it is able to resist
progressive deformity under physiological
loading”
13. Spinal Stiffness
• Euler 1744- Mathematical
theory for slender columns
• Critical Load (CL)directly
related to stiffness
• In vitro CL for LSpine 90N
• In vivo CL for Lspine
1500N
S.P. Timoshenko, J.M. Gere (Eds.), Mechanics of
materials, Van Nostrand Reinhold, New York, 1972
16. Insufficiency Fracture?
• Fracture -Break in the cortex
• Multidirectional
• Significant Force- Trauma
• Single event
• Insufficiency Spine- Failure of
Bone
• Compression
• Gravity- Atraumatic
• Cannot be attributed to a single
event
22. Sagittal Balance
The center of gravity (G)
moves forward
Large bending moment
created
Posterior muscles and
ligaments must
counterbalance increased
bending- Pain
Osteoporotic anterior
spine must resist larger
compressive stresses-
New fractures
G
23. Vertebral fracture healing
• Osteoporosis- Delayed bone healing?
• Lack of Callus formation in vertebrae
• Creeping Substitution
• Bone Grafts in spine
• Vertebral clefts- Pseudoarthrosis= Non Union
Hagasewa K et al Spine, 1988;23(20) 2201-06
Giannoudis P et al. Injury, Mar 2007;38(1),S90-99
24. Literature -1
• Biomechanical effectiveness of prophylactic vertebroplasty
• J Neurosurg Spine 8:442–449, 2008
• 12, 3 segment functional units- T12-L2
• Incremental loads up to 3.5x body weight
• Qct pre and post L1 augmentation
• Fractures occurred only after loads >2-3 times body weight
25. Literature 2
Prophylactic Vertebroplasty May Reduce the Risk of Adjacent Intact Vertebra From
Fatigue Injury
SPINE Volume 34, Number 4, pp 356 –364
• Biomechanical study on 14, 5 level thoracic spinal segments
• Divided prophylactic & standard groups
• Central vertebra augmented
• Compressive fatigue loading
• Strain Compliance -cortical shell and height
29. Prophylactic Augmentation
• Prophylactic augmentation strengthens osteoporotic vertebrae,
decreases the progression of vertebral height loss, reduces the
anterior body shift, and hence protects the adjacent intact
vertebra from elevated flexion bending.
• Vertebra is osteoporotic and adjacent level is located at pivot or
lordotic level of spinal column
• Prophylactic augmentation may be an option to prevent the
AVF.
• Spine (Phila Pa 1976). 2009 Feb 15;34(4):356-64.
67. Role of Prophylactic Cement
Augmentation
• Redefine an osteoporotic fracture?
• Is loss of height too late for augmentation?
• Biomechanical segment cement augmentation
• ‘Prophylactic’ augmentation in unstable segments
• Targeted cementing with channel creation
• Columnar construct to prophylactic cementing
• Imperative that complications are low/nil- High Viscosity
