Transcript Aseptic loosening of Hip Prostheses

Aseptic loosening of
Hip Prostheses
Ernesto Pintore
Clinica Malzoni
Agropoli - Italie
Prosthetic Surgery
=
Life quality
AIM OF REVISION
SURGERY
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GOOD FUNCTION
• QUALITY OF LIFE
TECHNICALLY DIFFICULT
VARIETY OF IMPLANTS
LEARNING CURVE
INSTRUMENTS
RECENT PROGRESS:
-BIOMATERIALS
-DESIGNS
-IMPROVED CEMENTING
TECHNIQUE
-MODULAR PROSTHESES
• SEPTIC LOOSENING
• ASEPTIC LOOSENING
SEPTIC LOOSENING
• CLINIC
• LABORATORY
• X-RAY
• SCINTIGRAPHY
SEPTIC
LOOSENING
ASEPTIC LOOSENING
MECHANICAL FAILURE:
“Aseptic loosening of one or both
components, fracture of a
component, recurrent dislocation of
the hip, fracture of the femoral
shaft.”
Callaghan JJ; Salvati E.A. et al.
JBJS 1985
ASEPTIC LOOSENING OF
THE FEMUR
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MALPOSITION OF THE STEM
FRACTURE OF THE IMPLANT
FRACTURE OF THE FEMUR
RECURRENT DISLOCATION
INADEQUATE STEM DESIGN
INADEQUATE CEMENTING
TECHNIQUE
• INADEQUATE CEMENT LAYER
ASEPTIC LOOSENING OF
THE CUP
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POOR BONE COVERAGE
MALORIENTATION too vertical, >60°
POLYETHYLENE FAILURE
EXCESSIVE HIGHT OF THE CUP >35mm
compared to the contralateral
• INADEQUATE CEMENT TECHNIQUE
fixation holes and thickness of cement layer
• SMOOTH CUPS and RE-CEMENTED
• THREATED CUPS
X-RAY FEMUR
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VARUS-VALGUS OF THE STEM
VERTICAL SUBSIDENCE
HORIZONTAL MIGRATION
RADIOLUCENCY
OSTEOLYSIS
FRACTURE OF THE CEMENT
X-RAY ACETABULUM
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VERTICAL MIGRATION
HORIZONTAL MIGRATION
CUP HIGHT
CUP ANGLE
RADIOLUCENCY
OSTEOLYSIS
POLYETHYLENE FAILURE
FEMORAL BONE STOCK
Poor: if the thickness of either
aspect of the cortex on the AP
x-ray had decreased by 50%,
along a 10 cm segment of
femoral stem, compared with
the original arthroplasty, or if
the thickness of both aspect of
the cortex had decreased this
amount along a 5 cm segment
ACETABULAR
BONE STOCK
• CUP MEDIAL TO THE KOHLER’S
LINE (any part of the implant)
• MEDIAL WALL (< 2mm thickness)
• VERTICAL DISTANCE ( > 1 cm
between the line trough the tear drop and
the higher point of the cement layer
compared to the contralateral)
A.A.O.S.
Classification
for bone stock damage
• MILD
• MODERATE
• SEVERE
CLINIC
- PAIN
- START UP HECITANCY
DEFINITION OF
ACETABULAR LOOSENING
(Harris and Mc Gunn JBJS 1986)
DEFINITE LOOSENING:
• change of position of the implant, or cement.
• fracture of the cement
• radiolucency at the cement-implant interface
PROBABLE LOOSENING:
• no migration or change of position
• continuous radiolucency (100%) at cement-bone
interface
POSSIBLE LOOSENING:
• radiolucency 50%-99% at the cement-bone interface
WEAR DEBRIS
The wear debris is responsible of a local
inflammatory reaction with histyocytes
and mast cells proliferation, that leads to
osteolysis and loosening of the implant.
OPERATIVE TECHNIQUE
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CHOICE OF THE APPROACH
POSTERO-LATERAL APPROACH
OSTEOTOMY OF THE TROCHANTER
FEMORAL “WINDOW”
WAGNER TECHNIQUE
REMOVAL OF THE CEMENT
IMPLANTS
IMPLANTS
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STANDARD STEM
LONG STEM
SURFACE
MODULAR PROSTHESES
“LOCKING NAIL” PROSTHESES
BONE GRAFT
• AUTOGRAFT
• HOMOGRAFT
• ALLOGRAFT
Only an accurate reconstruction of the
anatomy can allow a good result in the
revision surgery ( Bone bank)
CEMENT OR NOT CEMENT?
ALTHOUGH MODIFICATION AND
IMPROVING OF CEMENTING TECHNIQUE
HAVE DECREASED THE INCIDENCE OF
FEMORAL AND ACETABULAR LOOSENING
IN THR, THRE IS NO EVIDENCE
DEMONSTRATING BENEFITS IN REVISION
SURGERY WITH THE CEMENT.
Engh C.; Glassman A.
(Instructional course lecture 1991)
CRITERIA FOR DETERMINING
BIOLOGIC FIXATION
• BONE INGROWTH
• STABLE BONE-FIBROUS TISSUE
• UNSTABLE IMPLANT
BONE INGROWTH
• NO
IMPLANT MIGRATION
• ADAPTIVE REMODELING OF
THE SURROUNDING BONE
CAUSES OF SUCCESS IN
FEMORAL REVISION
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FRESHENING THE BONE
RESTORE THE BONE STOCK
IMPROVED TROCHANTERIC FIX.
TREATEMENT OF PERFORATIONS
ADEQUATE STEM:
-Extensevely porous coated
-Design (filling)
CAUSES OF FAILURE
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BAD BONE STOCK
TROCHANTERIC PROBLEMS
MISDIAGNOSED PERFORATIONS
INADEQUATE DESIGN OF THE IMPLANTS
DYSPLASIC AND NECROTIC HIPS
INFECTION
CURVE OF LEARNING
RESULTS OF
UNCEMENTED REVISIONS
(C. Engh - A. Glassman)
•163 hips
•80,7% of bone ingrowth
•12,3% of stable fibrous tissue
•3,5% unstable implants re-revised
COMPLICATIONS
SYSTEMIC COMPLICATIONS
• Urinary infections
• Cardiac problems
• DVT
• Pulmonary embolism
• Blood loss (1000-1500 ml)
LOCAL COMPLICATIONS
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Superficial and deep infections
Trochanteric nonunion (10%)
Trochanteric problems
Fracture of the femur
Perforation of the femur
Fracture of the pelvis
Recurrent dislocations (9-12%)
Ectopic bone
Aseptic loosening of a Bousquet cup 6 years later
Revision with uncemented cup and auto-homograft
Revision surgery is technically difficult and
requires an experienced surgeon and economic
means to achieve the most performant devices.
There are many complications and the results
are not always good.
The learning curve is long
but despite this we beleave
that this is the surgery wich
we have to develop in the
future.