FRACTURE FIXATION IN OSTEOPOROTIC BONE Stephen Kates, MD Hansjӧrg Wyss Professor of Orthopaedic Surgery Department of Orthopedics and Rehabilitation Associate Director, Center for Musculoskeletal Research University of Rochester Medical Center Michael Blauth Norbert Suhm Jorg Goldhahn THE AMERICAN GERIATRICS SOCIETY Geriatrics Health Professionals. Leading change. Improving care for older adults. AGS
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THE AMERICAN GERIATRICS SOCIETY Geriatrics Health Professionals.
FRACTURE FIXATION IN OSTEOPOROTIC BONE Stephen Kates, MD Hansjӧrg Wyss Professor of Orthopaedic Surgery Department of Orthopedics and Rehabilitation Associate Director, Center for Musculoskeletal Research University of Rochester Medical Center Michael Blauth Norbert Suhm Jorg Goldhahn. AGS. - PowerPoint PPT Presentation
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FRACTURE FIXATION IN OSTEOPOROTIC BONE
Stephen Kates, MDHansjӧrg Wyss Professor of Orthopaedic Surgery
Department of Orthopedics and RehabilitationAssociate Director, Center for Musculoskeletal
ResearchUniversity of Rochester Medical Center
Michael BlauthNorbert SuhmJorg Goldhahn
THE AMERICAN GERIATRICS SOCIETY
Geriatrics Health Professionals.
Leading change. Improving care for older adults.
AGS
LEARNING OUTCOMES
• Understand the factors influencing fixation in cortical and trabecular bone affected with osteoporosis
• What implant characteristics help with fixation?
• What aspects of surgical fixation are important?
• Understand basic metabolic bone work-up
Slide 2
DEFINITIONS
• Insufficiency fracture: bone fails with normal weight-bearing
• Fragility fracture: result of a fall from a standing height or less
Slide 3
CONTENTS
• Osteoporotic cortical bone Biomechanical properties Choice of implants Surgical technique
• Trabecular bone Biomechanical properties Choice of implants Surgical technique
Slide 4
CONTENTS
• Osteoporotic cortical bone Biomechanical properties Choice of implants Surgical technique
Slide 5
BONE MASS CHANGESDURING LIFE
• Peak bone mass is reached at age 25
• Heredity
• Medications
• Diet, tobacco, and alcohol
• Race / weight
Slide 6
CONTENTS
• Osteoporotic cortical bone Biomechanical properties Choice of implants Surgical technique
Slide 7
LOCKED-PLATE PRINCIPLE
Slide 8
by bending load
PULLOUT OF REGULAR SCREWS
Slide 9
SHEARING CONVENTIONAL PLATE OR SCREW DOWN
Slide 10
RESISTANCE AGAINST BENDING LOAD
Slide 11
RESISTANCE AGAINST BENDING LOAD IN LOCKED PLATE
Plate-screw connectionis solid
Screw-bone interfaceFails as a unit
Slide 12
CONTENTS
• Osteoporotic cortical bone Biomechanical properties Choice of implants Surgical technique
Slide 13
UNI- VS. BICORTICAL SCREW FIXATION
female
Slide 14
Thin cortices: choose screw diameter as large as possible
Slide 15
FAILURE WITH UNICORTICAL SCREWS
10 months postop.
5 days later
Slide 16
+6%
+18%
+36%
0
100
200
300
400
500
600
Load (N)
4.5 mm Cortex, bicortical
5.0 mm Locking, bicortical
4.0 mm Locking, bicortical
4.0 mm Locking, unicortical
BIOMECHANICS: NORMAL BONE
Slide 17
+17%
+82% +91%
0
100
200
300
400
500
600
Load (N)
4.5 mm Cortex, bicortical
5.0 mm Locking, bicortical
4.0 mm Locking, bicortical
4.0 mm Locking, unicortical
BIOMECHANICS:OSTEOPENIC BONE
Slide 18
BRIDGING WITH LOCKED IMPLANT
Slide 19
CONCEPTS OF PLATE FIXATION IN OSTEOPOROTIC BONE
• ? compression technique
• Bridge plating useful
• Neutralization plates useful
• Long plate for bone protection
Slide 20
CONTENTS
• Trabecular bone Biomechanical properties Choice of implants Surgical technique
Slide 21
OSTEOPOROSIS
Normal bone Osteoporosis
In osteoporotic metaphyseal bone:•Fewer trabeculae for screws to engage
•Loss of critical bony interconnections
•Thinner internal support
Slide 22
SIGNS YOUR PATIENT HASPOOR-QUALITY BONE
• Poor dentition: teeth are formed similarly to bone
• Multiple vertebral compression fractures• Previous hip, radius, or tibial plateau fracture• End-stage renal disease• On steroid therapy• Anticonvulsant use
• Cut out• Loss of screw fixation• Spontaneous fractures
Slide 24
CONTENTS
• Trabecular bone Biomechanical properties Choice of implants Surgical technique
Slide 25
Lag screw Helical blade
Flat surface, increased area
Slide 26
Less loss of bone with helical blade (right)
CHOICE OF IMPLANT:ONE FIXED ANGLE VS. MANY
One fixed angle with blade plate Multiple fixed angles, longer implant
Elderly woman who fell down one step
Slide 27
VARUS COLLAPSEDUE TO LACK OF MEDIAL BUTTRESS
Slide 28
CONTENTS
• Trabecular bone Biomechanical properties Choice of implants Surgical technique
Slide 29
INTRA-OP IMPACTION
Slide 30
Augmentation to Improve Screw Fixation
Enlarges the bone implant surface area
NOT FDA APPROVED!Slide 31
AUGMENTATION IN PRACTICE
32
Slide 32
IF BONE IS VERY POOR, CONSIDER PROSTHETIC REPLACEMENT
Slide 33
DON’T FORGET THE SOFT TISSUES
The wound must heal also
Skin is also 98 years old
Slide 34
BASIC OSTEOPOROSIS WORK-UP: METABOLIC
• 25-OH vitamin D level
• Intact PTH level
• Calcium
• Phosphate
• TSH
• Albumin level
Slide 35
RADIOLOGIC WORK-UP OF OSTEOPOROSIS: DEXA SCAN
• DEXA is gold standardT score is comparison to normal young boneZ score is comparison to peers
• Treat with fragility fracture and osteoporosis, osteopenia
Slide 36
VITAMIN D REPLETION
• Vitamin D2 50,000 units POLevel 010 ng/dL: 3 times / weekLevel 1120 ng/dL: 2 times/weekLevel 2132 ng/dL: 1 time/week
• For 612 weeks, then recheck level
• Maintain with vitamin D3 1200 IU/day
Slide 37
TREATMENTSAFTER VITAMIN D REPLETION
• For viable patients:BisphosphonatesSelective estrogen receptor modulators
(SERMs)Parathyroid hormone
• Don’t forget the bone itself: treat the osteoporosis or refer
Slide 38
TAKE-HOME MESSAGES
• Age & bone quality affect cortical and trabecular bone in different ways
• Absolute stability often not possible
• Principles of fixation: Angular stability Fracture reduction Long bridging plates Enlarged surface area of implant / bone Augmentation Prosthetic replacement