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  1. osteolysis
    • particulate debris
    • macrophage activted osteolysis
    • prosthesis micromotion
    • particulate debris dissemination
  2. radiostereometric analysis
    most accurate/ precise way to measure wear of lolyehtylen
  3. particulate debris formation types of wear
    • adhesive wear
    • abrasive wear
    • third body wear
    • linear wear
    • volumetric wear
    • olumetric wear more or less creates a cylinder

    • V=3.14rsquaredw
    • V is volumetric wear, r is the radius of head, w is linear head wear
    • head size is most important factor in predicting particles generated
  4. factors that increase wear THA
    • thickness < 6mm
    • malalignment of components
    • patients < 50 yo
    • men
    • higher activity level
  5. particulate size
    < 1 micron
  6. macrophage activate cytokines
    • TNF alpha
    • TGF beta
    • osteoclast activating factor
    • oxide radicals
    • Hydrogen peroxide
    • acid phosphatase
    •  Il-1; Il-6
    • prostaglandins
  7. osteoclast activation
    • TNF increases RANK
    • increase VEGF with UHMPWE enchances  rank/ rankl
  8. osteolysis blood test ( protein)
    N-telopeptide urine level
  9. PJI infection rate

    TKA
    THA
    • 1-2% TKA 
    • revision 5-6%

    • 0.3-1.3% THA
    • 3-4%
  10. 4 most common organisms for PJI
    • s. aureus
    • s. epidermidis
    • coag neg staph
    • candida
  11. acute pji

    chronic pji
    • within 3-6 weeks ( cdc <90 days)
    • - no biofilm production

    • chronic
    • -biolfilm forms after 4 weeks
    • --15% cells/ 85% glycocalyx

    • bone scan
    • -99% sensitive /30-40 % specificity
  12. PEt scan for PJI
    sensitivity 98%/ specificity 98%
  13. MSIS criteria
    • major criteria
    • -sinus tract
    • -pathogenisolated from 2 seperate cultures

    • minor criteria
    • -elevated esr ( 30) or crp (>10)
    • -elevated WBC (1,100 knees/ 3000 hips)
    • -PMN ( >64% knees, >80 hips)
    • -purulence in joint
    • -pathogen isolatation in 1 culture
    • ->5pmn in 5 hpf @ 400x
  14. PJI LABS
    • crp- peaks 2-3 days ; normal after 2-3 weeks
    • -acute < 100 acute 10 mg/dl

    • ESR- peak 5-7 days, ormalized after 3 weeks
    • chronic over 30

    • SIL-6- peak 8-12 hr after surgery, normal 3days
    • sensitivity 100%/ specificity 95%
    •  false positive
    • -RA
    • -MS
    • -AIDS
    • -PAgets
  15. PJI Surgical options
    • poly exchange and iv abx 4-6 weeks
    • --50-55% success rate


    • one stage replacement
    • -low virulence, no sinus tract healthy patient,no bone graft, no long abx use
    • -abx impregnated cement
    • -success 75-100%

    • two stage
    • -prosthesis removal, antibiotic spacer, IV antibiotics for 4-6 weeks and delayed reconstruction
    • delayed reimplantation >6 weeks has a 70-90% success rate

    • resection arthroplasty
    • -total knee success rate is 50% to 89%
    • -total hip success rate is 60% to 100%

    • arthrodesis
    • -71-95 % success

    amputation
  16. spacer abx mix
    40g of cement shoud have 3g vanco and 4g tobramycin



    highest doses without systemic toxicity

    • 12.5g tobramycin:40g cement
    • 10.5 vancomycin:40g cement
  17. pji local abx choices
    • aminoglycosides ( genta/ tobra)
    • -gram neg bacilli
    • -synergistic against g+ coc ( staph/entero)

    • vanco
    • -g+ cocci
  18. incidence tha fracture
    intraoperative fractures

    • 3.5% of primary uncemented hip replacements
    • 0.4% of cemented arthroplasties

    postoperative fractures

    • 0.1%
    • most common at stem tip
  19. risk factors femur fracture in THA (7)
    • impaction bone grafting
    • female gender
    • technical errors
    • cementless implants
    • osteoporosis
    • revision
    • minimally invasive techniques (controversial)
  20. vancouver intraop classification
    • a1- proximal metaphysis, cortical perf
    • a2- prox metaphysis non displaced crack ( wire)
    • a3- prox metaphysis, unstable (fully porous coated stem/ tapered flute stem

    • b1-diaphyseal, cortical perf ( fully porous bypass by 2 cortical diamter+/- strut)
    • b2-diaphyseal, nondisplaced crack ( cerclage, fully porous)
    • b3-diaphyseal, displaced unstable (fully porous)

    • c1-distal to stem tip( bone graft, struth graft, fully porous)
    • c2-distal non displaced crack, ( cerclage)
    • c3- distal to stem unstable ( orif)
  21. vancouver post op classification
    a-fracture in troch-adress osteolysis ( GT less than 2cm conservative)

    • b1-well fixed stem- orif, cerclage
    • b2-loose stem good proximal bone stock -long porous cementless stem
    • b3-poor proximal bone stock-prox femoral allograft/ proximal femoral repalcement

    c-below plate - orif
  22. causes of increased q angle
    • internal rotation of femoral prosthesis
    • medialization of femoral component
    • internal rotation or medialization of tibia
    • placing patella prosthesis to lateral
  23. q angle
    • asis to center of patella
    • patella to tibial tuberosity
  24. femoral prosthesis axis ( 3)
    • whiteside line
    • epicondylar axis ( parellel to tibia cut)
    • posterior condylar axis
    • -3 degree of internal rotation from transepicondyalr axis ( therefore rotate 3 degrees ext)
  25. paprosky acetabular bone loss
    type 1- minimal deformity, intct rim

    type 2a- superior bone lysis with intact superior rim

    type 2b-  absent superior rim, superolateral migration

    type 2c-localized destruction of medial wall

    type 3a- bone loss 10am -2 pm superolateral cup migration

    type 3b- bone loss 9am-5am, superomedial migration
  26. aaos classification acetabular one loss
    • type 1- segmental
    • type 2- cavitary
    • type 3- combined deficiency
    • type 4-pelvic dicontuinity
    • type 5 arthrodesis
  27. aaos classfication femoral bone loss
    • type 1- segmental
    • type 2- cavitary
    • type 3- combined
    • type 4-malaignment
    • type 5- stenosis
    • type 6- femoral discontinuity
  28. papropsky femur bone loss
    • type 1- minimal metaphyseal bone loss
    • type 2- extensive metaphyseal but intact diaphysis
    • type 3- extensive metaphyseal , but atleast 4 cm diaphysis scratch fit
    • type 3b- extensive, less than 4 cm
    • type 4- extensive metaphyseal+ nonsupportive diaphysis
  29. acetabular position recommended postion
    anteversion 5-25%

    abduction 30-50%
  30. surgical aproach for version
    posterior err towards more anteversion

    anterior err to less anteversion
  31. combined version ideal
    37 degrees
  32. pros of mobile bearing UKA
    weightbearing throgh meniscuses increases conformity and contact without increasing constraint

    decrease wear pattern

    cons: harder, can dislocation
  33. uka indications
    classic: older than 60, low demand less than 82 kg
  34. contraindications TKA (9)
    • inflamm arthririts
    • ACL deficiiency
    • varus > 10 degrees
    • valgus over 5 degrees
    • rom restricted ( less than 90 degrees or flexion of 5-10 degrees)
    • previous meniscectomy
    • tricompartmental OA
    • overweight
    • grade 4 patellofemoral oa
  35. mobile bearing UKA 15 year survivorship
    93%
  36. disadvantage metal on metal
    • 12-24 months increase metal ions then hits steady state
    • pseudotumors
    • hypersensitivity type 4
    • - te cell mediated ( macrophages)
    • -antigen activated present to class 2 mhc
  37. ceramic squeeking risk factord
    • edge loading
    • impingement and acetabular malposition
    • third body wear
    • loss of fluid film lubrication
    • thin flexible titatnium stems
    • stripe wear- cresent shape wear on head
  38. HO THA complication: brooker
    class I: represents islands of bone w/in soft tissues about hip 

    class II: inclues bone spurs in pelvis or proximal end of femur leaving at least 1 cm between the opposing bone surfaces; 

    class III: represents bone spurs that extend from pelvis or the proximal end of femur, which reduce the space between the opposing bone surfaces
  39. Heterotropic ossification prophylaxis
    600-800 GCY within 24-48 hour following procedure

    oral indomethacin
  40. pseudotumor workup
    • metal ions( cobalt chromium on repeat visits)
    • -MR with metal subtraction
    • rule ut infection
  41. sciatic nerve palsy THA
    • 0-3 %
    • peroneal nerve division most common ( 80%)

    nerve closes to ischium care with posterior acetabular retraction when hip is flexed
  42. sciatic nerve palsy THA risk factors
    • DDH
    • revision
    • female
    • limb lengthening
    • post traumatic oa
    • 35-40% recover full strneght
  43. sciatic nerve palsy THA treatment
    • hip in extension and knee in flexion
    • immediate excvation in or
    • AFO for foot drop

    intraop- downsize compnents or subtroch osteotomy
  44. hip osteonecrosis + risk factors
    • 10% of THA
    • 80% bilateral

    • risk factors:
    • - irradation
    • -trauma
    • - leukemia/ lymphoma
    • - caisson disease
    • - sickle cell
    • -gaucher disease
  45. idiopathic avn- cascade
    • coagulation of intraosseous microcirculaton
    • venous thrombosis
    • retrograde arterial occlusion
    • intraosseous hypertension
    • decreased blood flow femoral head
    • avn of head
    • chondral fracture and collapse
  46. AVN femoral head
    • femoral head fracture- 75-100%
    • basicervical fracture 50%
    • cervicotrochanteric fracture 25%
    • hip dislocation 2-40% (2-10% if reduced within 6 hours)
    • intertroch fracture
  47. kerboul combined necrotic angle
    low risk group- combined necrotic angle less than 190

    moderate risk group- combined necrotic angle 190-240

    high risk- combined  necrotic angle of more than 240

    take ant-post  angle and add to lateral angle
  48. external rotation on radiographs will
    • falsely decrease offset
    • create valgus appearing femoral neck
    • falsely decrease femoral canal diameter
  49. tear drop what makes it
    created by superposition of the most distal part of the medial wall of the acetabulum and the tip of the anterior/posterior horn of acetabulum
  50. steinberg classifcation avn
    Image Upload
  51. MRi finding  AVN hip
    double density appearance

    • T1: dark (low intensity band)
    • T2: focal brightness (marrow edema)
  52. AVN hip treatment
    • bisposphonates/ aspirin
    • core decompression +/ - bone graft
    • rotational osteotomy 
    • vascularized fibular bone graft

    THA
  53. Su classification
    • 1- proximal to femur component
    • 2-component and moves proximally
    • 3-distal to upper edge of anterior flange
  54. retrogade nail femur
    may cause more posterior start point and therefore extension of femur
  55. felix classification
    • 1-fracture tibial plateau
    • 2-fracture adjacent to ste
    • 3- distal to stem
    • 4- tibial tubercle
  56. goldberg classification
    Image Upload
  57. OA per 100,000
    • 88 tha
    • 240 tka
  58. cell biology OA
    • MMP
    • tissue inhibitor MMP 
    • IL-1, Il-6, TNf-alpha
  59. pe failure TKA
    if less than 8mm

    ( measure from bottom of metal tray)
  60. oxygen depleted PE
    more resistant to abbrasive and adhesive wear
  61. relative contraindications hip resurfacing
    • coxa vara ( increased fracture)
    • LLD
    • female sex child bearing age ( metal ions)
    • renal failure
  62. Joint reaction force formula
    Solving for joint reaction force (R)

    step 1:  calculate My

    principle

    • sum of all moments equals 0 
    • in this case, the moments are created by My and W

    • equation
    •  (A x My) + (B x W) = 0

    • assume A = 5cm and B = 12.5cm (this information will be given to you)
    • My = 2.5W


    step 2:  calculate Ry

    • Ry = My + W
    • Ry = 2.5W + W
    • Ry = 3.5W

    step 3:  calculate R

    R = Ry / (cos 30°)

    • R = 3.5W / (cos 30°)
    • R = ~4W
  63. actions that decrease joint reaction force
    move acetabular component medial inferior and anterior

    • femur:
    • increase offset  
    • long stem prosthesis
    • lateralize greater troch
    • varus neck

    cane contralateral hand
  64. LLD abduction
    longer leg
  65. cocktail for TKA/THA6
    • 60 ml levobuipvicaine 2.5%
    • 30 mg ketorlac
    • 0.5 mg adrenaline
    • 40 ml NS
  66. range of motion needs TKa
    Range of motion

    requirements

    swing phase of gait

    65° of flexion

    activities of daily living

    90° of flexion

    stairs

    95° of flexion

    rise from a chair

    105° of flexion
  67. THA screw placement zone
    • posterior superiod quadrant:
    • -target zone
    • elevate hip centre maybe sciatic at risk

    • posterior inferior
    • -caution zone
    • -over 20 mm dangerous
    • -sciatic nerve, inf gluteal vessels nerve, pudendal nerve vessel

    • ant- inf zone is danger
    • -obturator nerve and artery and vein

    • ant  sup quadrant
    • -external illiac vessels at risk
  68. midvastus approach tka- contraindications
    • ROM <80 degrees
    • obese patient
    • hypertrophic arthritis
    • previous HTO
  69. varus deformity steps of release tka
    • 1-deep mcl
    • 2-medial osteophyte
    • 3-release posteromedial corner
    • 4-medialtibial reduction osteotomy
    • 5- pcl release
    • 6-release semimebranosus
    • 7-pie crust mcl
    • 8
  70. valgus deformity release
    • 1- osteophyte
    • 2-posterolateral capsule
    • 3-iliotibial band ( if tight in extension)
    • 4-popliteus ( if tight in flexion)
    • 5-LCL
  71. felxion deformity release
    • 1-osteophyte
    • 2-posterior capsule
    • 3-additional femur resection
    • 4-gastrocnemius muscle
    • ( done at 90 flexion)
  72. causes patella baja
    • proximal tibia osteotomy opening wedge
    • tibia tubercle slide/ transfer
    • proximal tibia trauma
    • elevate joint line tka
    • acl recon
  73. insall salvati
    less than 0.8 is patella baja

    patella bone articualr surface length/ patellar tendon
  74. how to deal patella baja TKA
    • lower joint line( augment for distal femur, cute more tibia)
    • repalce patella and put puck more proximal

    tibia tubercle transfer
  75. TKA heterotrophic ossification risk factors
    • see on quas tendon and anterior femur hypertrophic arthrosis
    • male gender
    • obesity
    • notching
    • periosteal injury/ stripping
    • post op knee effusion
    • post op forced manipulation
  76. furia and pellegrini classifcation
    • class I: island of bone localized to suprapatellar soft tissues
    • Class II: bone organized into areas of ossification contiguous with the anterior distal femur    
    • Grade A: less than or equal to 5 cm
    • Grade B: greater than 5 cm
  77. Popliteal artery 

    origin
    • lies posterior to the posterior horn of the lateral horn of the lateral meniscus
    • origin before knee

    • a continuation of the superficial femoral artery
    • transition is at hiatus of adductor magnus muscle
    • anchored by insertion of adductor magnus as enters region of posterior knee
  78. TKA FLAP possibility
    medial gastrocnemius rotational flap (medial sural artery): anterior and medial defects

    ateral gastrocnemius rotational flap (lateral sural artery): lateral defects
  79. hip arthrodesis
    • reduces efficiency of gate by 50%
    • 30% more oxygen expenditure


    • 20-35° of flexion
    • 0°-5° adduction
    • 5-10° external rotation
  80. HTO
    varus deformities


    varus-producing high tibial osteotomy

    success rate is 87% patients in 10 years

    valgus-producing high tibial osteotomy

    success rate is 50-85% of patients in 10 years

    best results achieved by overcorrection of the anatomical axis to 8-10 degrees of valgus

    specific contraindications

    • narrow lateral compartment cartilage space with stress radiographs
    • loss of lateral meniscus
    • lateral tibial subluxation >1cm
    • medial compartment bone loss >2-3mm
    • varus deformity >10 degrees
  81. HTO  recurrence deformity
    • 60% failure rate after 3 when
    • failure to ovvercorrect
    • patients are overweight

    • loss of posterior sloe
    • patella baja
    • compartment syndrome
    • peroneal nerve palsy
    • malunion  or non union

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Author:
jaykruijt
ID:
334609
Filename:
recon
Updated:
2017-10-06 22:11:42
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recon
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recon ortho
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