2009年8月17日 星期一

MTOS-Ch.18-Arthroplasty for ITF

ITF:

most patient: union uneventfully



Becautious

1. Pathological fx

2. Unstable or comminuted

3. Medical comorbidity

4. Severe osteopenia

5. Previous implant failure



must r/o infection nonunion in previous operation failure

1. ESR & CRP

2. Intra-OP culture or smear



Approach

1. W/O greater trochanter fracture: AL or PL approach

2. W/ greater trochanter fracutre: Trochanter osteotomy aproach



Issue 1: When to remove prosthesis

1. after surgical dislocation


  • femoral shaft w/o implant is weak. and his/her hip joint is stiff. iatrogenic shaft may be occured during surgical dislocation if implant was removed

  • 先切掉head? eliminate femoral shaft fracture?

Issue 2: choice of Cup



  • cementless with screw sugmentation

  • press-fit w/o screw fixation is not recommended

Issue 3: choice of stem

calcar replacing prosthesis

  • restore length
  • reduce lesser or greater tuberosity
  • fixation with Wire or cable

Issue 4: preparation of femoral canal

  • scleroting tract, callus, deformity: deflecting reamer or broacher → iatrogenic fracture or femora canal peforation
  • high speed burr to open femoral canal, then prepare femoral canal with reamer and broacher

Issue 5: stem length in femur with previous implant fixation

  • 6 cm distal to previous screw hole ( 2 fold diaphysis diameter)
  • avoid stress riser from screw hole

Issue 6: cemented stem

  • good choice for severe osteopenic patient
  • large cement leakage: cause of late periprosthetic fracture
  • Clean and curette extravasation of cement

Issue 7: greater trochanter fracture

  • cable or multiple wires
  • stable enough for early mobilization
  • autogenous bone grafting is recommended (harvested from femoral head)
  • avoid abductor muscle strengthening in first 6 weeks

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