Primary Hip Arthroplasty Cemented

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Primary Hip ArthroplastyCementedUncemented
Frank R. Ebert, MD
Union Memorial HospitalBaltimore, Maryland
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Johns HopkinsUnion Memorial
Orthopædic Review Course
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Anatomic Approach

• Anterior Approach
• Anterior-Lateral Approach
• Posterior Approach
• Medial Approach

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Anatomic Approach

• Open Reduction CDH
• Pelvic Osteotomies
• Intra-Articular Fusion
• Rarely Total Hip

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Internervous Plane

• Superficial
• Sartorius / TFL ( Femoral/Superior gluteal
  )
• Deep
• Rectus / gluteus medius ( Superior gluteal
  )

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Anterolateral Approach

• Most common for THA
• ORIF of femoral neck
• Synovial biopsy of the hip

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Anterolateral Approach

• Internervous plane none
• TFL / gluteus medius
• Superior gluteal / Superior gluteal

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Lateral Approach

• Dangers
• Superior gluteal nerve
• Femoral nerve

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Medial Approach

• CDH open reduction
• Psoas Release
• Obturator Neurectomy
• Biopsy or Treatment of tumors of femoral neck

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Medial Approach

• Internervous plane ( only deep )
• Superficial
• Adductor Longus / gracilis
• Deep
• Adductor Brevis / magnus

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Posterior Approach

• Internervous plane none
• splits gluteus maximus ( inferior gluteal )

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Primary Hip Arthroplasty

• Posterior Approach
• Total hip replacement
• ORIF of posterior column fractures
• Dependent drainage of hip sepsis

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Primary Hip Arthroplasty

• Posterior Approach
• Sciatic Nerve
• Inferior gluteal artery

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Primary Hip Arthroplasty

• Design Features
• Size
• Shape
• Device configuration
• Material / physical properties

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Primary Hip Arthroplasty

• Resist Composite Failure
• Prosthetic Device
• Bone Cement
• Cancellous Bone
• Cortical Bone

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Primary Hip Arthroplasty

• Design Features
• Femoral Head
• Neck
• Stem
• Collar
• Acetabulum

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Primary Hip Arthroplasty

• Prosthetic Hip Loading
• Changes from externally loaded system to an
  internally loaded system

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Primary Hip Arthroplasty

• Femoral Head Design
• Articulating finish
• Head diameter

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DESIGNFEATURES
Femoral Head
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Primary Hip Arthroplasty

• 32 mm Head Size
• Greater acetabular loosening
• Greatest volumetric wear

Ritter COOR 76Morrey JBJS 89
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Design Features22mm Head Size

• u Greatest linear wear
• u Greatest acetabular penetration

MorreyJBJS 1989
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Design Features

• Charnley 22mm head diameter
• Compromise friction / wear

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Design Features28 mm Head Size

• Stable as 32mm head size
• Less torque than the 32mm head
• More favorable direct stress transmission patterns

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Primary Hip Arthroplasty

• 28 mm Head Size
• Compromise

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Primary Hip Arthroplasty

• Design Features Femoral Neck Geometry
• Neck stem angle 135º
• Neck stem offset
• large offset . . . Bending moment
• small offset . . . Decreases moment arm

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Primary Hip Arthroplasty

• Design Features
• Femoral Stem
• Length
• Shape
• Material properties
• Surface finish

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Primary Hip Arthroplasty

• Femoral Stem Design
• Cross sectional geometry
• Defines strength / stiffness
• Avoid sharp corners

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Primary Hip Arthroplasty

• Femoral Stem Design
• Large lateral volume
• Less tensile stress in the mantle laterally
• Large medial volume less tensile stress

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Primary Hip Arthroplasty

• Collar
• Primary role for optimal load transfer to
  proximal femur

Crowninshield JBJS 80Andriacchi JBJS 76
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Primary Hip Arthroplasty

• Collar
• Reduces adaptive bone resorption
• Reduce bending stress in the component
• Reduce stress in the distal cement

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Primary Hip Arthroplasty

• Fixation Features
• PMMA
• Weak link
• Poor fracture toughness
• Low tensile and fatigue strength
• Elastic modulus 1/3 lower than cortical bone

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Primary Hip Arthroplasty

• Fixation FeaturesPMMA Improvements
• Carbon Fibers Decreased cement intrusion /
  increased viscosity
• Low Viscosity Lower fatigue strength
• Centrifugation Improved tensile and fatigue
  strength

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PMMA Improvements

• Centrifugation 30 sec / 4000 rpm
• Vacuum

Burke JBJS 84Chin/Stauffer JBJS 90
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Primary Hip Arthroplasty

• Material Properties
• Stainless Steel high elastic modulus / low
  fatigue strength
• Cobalt Chrome highest elastic modulus /
  better yield / fatigue strength
• Titanium lower elastic modulus / less
  stiffness

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Primary Hip Arthroplasty

• Acetabulum Design
• Metal backed
• All polyethylene

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Primary Hip ArthroplastyCement Fixation

• The Femoral Side
• Results directly related to Surgical
  Techniques

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Primary Hip Arthroplasty

• Metal Backed
• Increased linear and volumetric wear
• Increased radiolucency, loosening, revision
• No series of documented superior results

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Improved Longevity Femoral Side

• Improved Longevity femoral side
• Plug canal
• Retrograde fill
• Avoid varus / valgus gt 5º

MulroyJBJS 95
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Primary Hip Arthroplasty
Grade Radiographic Appearance

• A White-Out
• B Complete Distribution
• C1 Extensive Radiolucent Line
• C2 Thin mantle lt 1 mm
• D Gross deficiencies

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Primary Total Hip

• 1st Generation Cement Technique
• Finger Packing No pressurization
• No Canal Prep Cast stem
• No Plug Narrow med border
• No Gun Sharp edges

WH Harris
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Primary Hip ArthroplastyCement Techniques

• Probable Improved Longevity
• Femoral Side
• Pressurize
• Centralize
• Continuous Cement Mantle

HarrisCOOR 97
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Cemented Long Term
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Primary Total Hip2nd Generation Cement

• William Harris Began 1975
• Gun 71 Super alloy
• Jet lavage Broad round medial border
• Canal Prep
• Cement Restriction

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Primary Total HipCemented Long Term

• Results 25 year Survivorship
• Acetabulum Survive
• Age lt 40 74 40-49 80 60-69 92
• Femur lt 40 83 40-49 82 60-69 95

Barry et al1998
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Primary Total Hip25 Year Follow-Up

• Total Aseptic Loosening
• Acetabulum
• Revision 14.5 Radiologic 19.4
• Total 33.9
• Femoral Revision 6.4 Radiologic 8.1

Callaghan, Johnston, JBJS 97. Harris Course 98
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Cemented Primary Total HipClinical Results
with2 Generation Techniques
RevisionRate
FollowUp
Hips

• Neumann (94) 241 17.6 yrs 8.3
• Schulte 93 330 20 yrs 3
• Wroblewski 93 1324 20 yrs 6
• Kavanagh 94 333 20 yrs 16

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Cemented Primary Total HipClinical Results
with2º Generation Techniques
RevisionRate
FollowUp
Hips

• Barrack 92 50 12 yrs 0
• Madey 97 356 15 yrs 1
• Mulroy 95 162 15 yrs 2
• Smith 98 161 18 yrs 5

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Primary Total HipClinical Results

• Cemented Total Hip 2nd Generation
• 14-17 year follow-up 102 hips
• Femoral loosening 2 revised
• Acetabular loosening 10 revised
• 42 radiologic

Mulroy, Harris, JBJS 95 COOR 97
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Cemented Primary Total HipClinical Results
Acetabular Side
Rev.Rate
Loosen-ing
Prosthesis
Hips

• Sullivan 94 Charnley 89 13 37
• Smith 98 CAD 65 23 26
• Callaghan 98 Charnley 93 19 15

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Primary Total Hip3rd Generation Cement Technique

• Bill Harris Began 1982
• Porosity reduction
• Rough surface
• Centralization
• Pressurization
• Pre-coat

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Primary Total Hip
Conclusions Cemented

• Plug and retrograde fill
• Avoid excessive varus/valgus
• Strive for 3-5 mm prox/med gt 2mm distal
• Do not ream / remove good cancellous bone

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Primary Total HipClinical Results

• Hybrid Construct
• Galante - 95 f/u 5 years
• Femoral 2 rad loose
• Acetabulum 2 rad loose
• Woolson - 96 f/u 6 years
• Femoral 5 revision
• Acetabulum 0 revision

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Design Features

• POROUS IMPLANT

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Uncemented THA

• Definition
• Press Fit
• Macrointerlock
• Microinterlock

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Design Features

• Pore Size Animal Studies
• 50 to 400 µm Optimal bone ingrowth

Bobyn Clinical Orthopedics 1980Engh JBJS
1987Collier Clinical Orthopedics 1988
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Micromotion

• 40 Micron Motion Bone Ingrowth (JBJS 79-A)
• 150 Micron Motion Fibrous Ingrowth (CORR,
  208)

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Design Criteria Long Term Implant Stability

• Initial Implant Stability
• Implant micromotion lt 50 mm of displacement
• Level of implant coating
• Type of coating

Kienapfel H.J. Arthroplasty 1999
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Design Criteria

• Uncemented Total Hip Arthroplasty
• Key Resistance to Rotation Around the
  Long Axis

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Design Criteria

• Uncemented Total Hip Arthroplasty
• Resist translation in 3 planes
• Axial
• Medial - lateral
• Anterior - posterior

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Design Criteria Uncemented Implants

• Level of Implant Coating
• Apply circumferential
• Avoid patch porous coats
• Smooth surface high failure rate

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Design Criteria Uncemented Implants

• Type of Coating
• 1. Macro-texturing doesnt work
• 2. Roughened titanium
• 3. Porous coating made of CoCr or Ti
• 4. Ti wire mesh
• 5. Plasma-sprayed Ti
• 6. Bioactives Hydroxyapatite / tricalcium
  phosphate

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Design Features

• Sintered Micro/Macro BeadsCr-Co-Mo/Ti
• Pore dimensions 100 to 400 mm
• AML PCA

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Fatigue strength
Process psi MPa
Forged 90 600 Cast 35 250 Sintered 25 150 Sintered
withcontrolled coating 30 200
Data from Pilliar, R.M. Clin. Orthop. 17642-51,
1983.
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Design Criteria Uncemented Implants

• Implant Geometry Implant Stability
• 1) Wedge-shaped metaphyseal filling
• 2) Single wedge-shaped implants
• 3) Tapered stems
• 4) Diaphyseal fixation cylindrical or fluted
  stems

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Design Criteria

• Uncemented Implants
• Requires cortical fixation
• Metaphysis
• Metaphysis Diaphysis
• Diaphyseal

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Design Criteria Uncemented Implants

• Bioactives Osteoconductive
• Tricalcium dissolves more rapidly than
  hydroxyapatite
• Thickness 50 mm
• More crystalline hydroxyapatite slows resorption

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Uncemented Primary Total HipClinical Results
Femoral Side

• Titanium Cobalt Chrome
• Cobalt Chrome increased stress- shielding
• Straight Stems with varying degrees of
  medullary fill often used
• Anatomic Stems have not been a great
  advantage

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Design Features

• u Straight Stem
• u?An Anatomic Stem

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Design Features

• Proximal Coating

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Design Features

• u Proximal coating Anatomic design
• u Maximum fit in certain priority areas
• u Maximal load transfer
• u Resist axial loading and torsional loads

Poss Clinic
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Design Features

• u Both greater distal motion at interface
• Compared with proximal motion

Callaghan, JBJS 92
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The HGP stem (courtesy of Zimmer)
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Design Features

• Porous Implant

Fully coated
u
Proximal coating
u
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Design Features Porous Surface

• u 2/3 or fully coated
• 2 to 4 x increase in bone resorption

Engh Clinical Orthopedics 1988
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Design Features

• Fully Coated Porous Surface
• u Transfers stress distally under axial load

Proximal bone resorption
Engh Clinical Orthopedics 1988
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Retrieval Studies

• Engh
• Femur 57 ingrowth
• Acetabulum 32 ingrowth

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Radiographic Criteria for Bone Ingrowth

• Engh et al, (CORR 257)
• Absence of Reactive Lines
• Spot Welds Endosteal Bone
• Implant Instability 2 mm
• Pedestal
• Calcar Atrophy / Stress Shielding

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Uncemented Primary Total HipClinical Results
Femoral Side

• Straight Stem Design loosening
• AML 507 hips 5- 14 yrs 1.2
• Harris/ Galante 121 hips 3- 6.2 yrs 3.3
• Omniflex 88 hips 2- 5.2 yrs 3.4
• Taperloc 145 hips 8- 12.5 yrs 0.7
• Trilock 71 hips gt 10 yrs 0

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Uncemented Primary Total HipClinical Results
Femoral Side

• Anatomic Stem Design loosening
• APR-1 100 hips 5-9.4 yrs 11
• APR-2 148 hips 2-5 yrs 0
• PCA 539 hips 6-8 yrs 7.6
• 100 hips gt 7 yrs 2.0

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Screw Fixation

• Less Micromotion, Better Ingrowth
• Conduit for Particulate Debris
• Neurovascular Injury

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Acetabular Design

• Hemisphere
• Screw Fixation
• Locking Mechanism

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Uncemented Primary Total Hip Main Recurrent
Concern

• Poly Wear Osteolysis

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Uncemented Primary Total HipClinical Results
Acetabular Side

• Femoral head size Acetabular thickness
• PCA 26 mm head no osteolysis
• PCA 32 mm head 26 osteolysis

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Uncemented Primary Total HipClinical Results
Acetabular Side

• loosening
• ARC 72 hips 12 yrs 1.4
• Harris/Galante 136 hips 5-10 yrs 0
• PSL smooth HA 316 hips 6-10 yrs 12 beaded
  HA 2.7
• PCA 241 hips 2-9 yrs 11 539 hips 7
  yrs 13.2 100 gt 7 yrs 4 rev.

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Uncemented Primary Total HipClinical Results
Acetabular Side

• Hemispherical shape rim fit
• Under ream No gt 2 mm
• Screws produced durable results -
  postop
• Disadvantage posterior sciatic N. Ant
  sup common iliac Ant inf obturator art /
  ner

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Complications in Total Hip Arthroplasty
Heterotopic Ossification

• Treatment
• Radiation pre-op or post-op 500 to 1000 Rad
  Remember to shield implant
• Indomethacin
• Ibuprofen
• Diphosphonates

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Complications In Total Hip Arthroplasty
Heterotopic Ossification 0.6 to 61.7

• Associated conditions
• Ankylosing spondylitis
• Forestiers disease
• Post traumatic arthritis
• Bilateral male osteophytic OA

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Complications in Total HipArthroplasty
Dislocation

• Component Impingement
• Proximal femur
• Femoral head skirt
• Acetabular component (elevated liner)
• Osteophytes / cement masses
• Head Size
• No difference 22 - 28 - 32
• 28 mm head gt 60 mm acetabulum increased
  rate
• 22 mm head gt 54 mm acetabulum increased rate

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Complications In Total Hip Arthroplasty
Dislocation 3

• Posterior approach slightly higher 4.6
• Neuromuscular problems
• Previous surgery (rate doubles)
• Malposition
• gt 25º anteversion
• gt 60º inclination
• Retroversion
• gt 15º femoral anteversion

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Treatment

• Bracing
• Spica cast
• Surgery

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Complications In Total Hip Arthroplasty
Dislocation

• Occult infection
• Trauma
• Profound weight loss

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Complications In Total Hip Arthroplasty
Thromboembolism

• Most common complication
• DVT 70 to 8
• PE 1 to 2

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Complications In Total Hip Arthroplasty
Thromboembolism

• Activation of clotting cascade
• Local vessel injury
• Stasis in the femoral vein

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Ultra-High Molecular Weight Polyethyleneis
defined as what type of material ?

• 1. Elastic
• 2. Viscoelatic-plastic
• 3. Rigid
• 4. Shear thinning
• 5. High friction

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The degradation of polyethylene following gamma
irradiation is related to what factor ?

• 1. Increased ionic bonding
• 2. Surface ion implantation
• 3. Free radical formation
• 4. Decreased covalent cross- linking
• 5. Decreased polymer density

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Why is cobalt-chrome alloy preferred over a
titanium alloy for a cemented femoral component
in a total hip arthroplasty ?

• 1. Less particulate metal debris
• 2. Less stiffness
• 3. Elastic modulus closer to bone cement
• 4. Cost-effectiveness
• 5. Better cement bonding ability

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What is the most common long-term complication of
cemented total hip arthroplasty in patients under
50 years of age?

• 1. Age
• 2. Dislocation
• 3. Periprosthetic femur fracture
• 4. Acetabular component loosening
• 5. Femoral stem fracture

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During a posterior approach to the hip joint,
profuse bleeding is encountered during incision
of the quadratus femoris.

• The bleeding is most likely from which artery?
• 1. Superior gluteal.
• 2. Inferior gluteal.
• 3. Lateral femoral circumflex.
• 4. Medial femoral circumflex.
• 5. Posterior femoral circumflex.

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Which is the correct order of the elastic modulus
of the following materials, from the lowest to
highest modulus?

• 1. Polyethylene, cancellous bone, cortical bone,
  titanium alloy, cobalt chrome alloy
• 2. Cancellous bone, cortical bone, polyethylene,
  titanium alloy, cobalt chrome alloy
• 3. Cancellous bone, cortical bone, polyethylene,
  cobalt chrome alloy, titanium alloy
• 4. Cancellous bone, polyethylene, cortical bone,
  cobalt chrome alloy, titanium alloy
• 5. Cancellous bone, polyethylene, cortical bone,
  titanium alloy, cobalt chrome alloy

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Thank You