per wretenberg - ki · artificial hip prosthesis in acute and non-union fractures of femoral neck...
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Historik
Första beskrivningen 1954
Artificial hip prosthesis in acute and non-union
Fractures of femoral neck
Horwitz et al. JAMA 155; 564-567 1954
Historik
Traktionsbehandling, 3 månaders balanserat sträck
The healing of human fractures in contact with
acrylic cement
Charnley J. Clin Othop 47; 157-163, 1966
Incidence
0.1 – 1% after Cemented THR
Kavanagh, Clin Orthop North Am, 2002
5.4% after uncemenetd THR
Berry, Clin Orthop, 2009
Periprostetsik fraktur
Intraoperativt
jämfört med cementerad primärplastik
- större risk vid ocementerad protes
- större risk efter revisionevisioner
- större risk vid benpackning?
Postoperative
- trauma
- osteolysis
- tumör
Riskfaktorer
Lös protes
Kvinnor
Metabola bensjukdomar
Osteoporos
RA
Preoperativ deformering av femur
Ocementerad protes
Vancouver classification
Type A: Trochanteric fractures
Type B: Fracture at stem level or just under the stem
Type C: Fracture distal to the stem
Type B fracture
B1: Stable prosthesis
B2: Loose prosthesis, good bone
B3: Loose prosthesis, bad bone
Vancouver classification reliability
Reliable classification,
Brady et al J Arthroplasty vol. 15(1) 2000
Vancouver classification reliability
Intra-observer k-value 0.77
Inter-observer k-value 0.64
K-value 0.10-0.20 = slight agreement
0.21-0.40 = fair
0.41-0.60 = moderate
0.61-0.80 = substantial
> 0.80 = almost perfect
Treatment of periprosthetic fractures
Nonoperativ
• Traction
• Orthosis
• None
» No adequate studies performed
Treatment
Vancover A
• Non operative, mobilization
• Fixation with screws
• Fixation with cables
• Fixation with plate and screws
Treatment
Vancover C
• Fixation with plate and screws
• Fixation with cables
• Fixation with nails
• (Fixation with screws alone)
Treatment
Vancover B1
• Cables (prox undisplaced fracture)
• Plate and screw, and or cables
• Mennen plate
• Strut graft with or without plate
• Strut graft and bone packing
• Revision THA
Platefixation
• Good/exact reposition possible
• Early mobilisation
• Partial (or full) weight bearing
• Risk of devsacularisation
• Bone resorption under plate
• Cement influenced by screws?
• Plate fracture
• Non union !
+
-
Technique
• Good exposure of fracture site needed
• Reduction and preliminary fixation
• Plate adjustment
• Combination of screws, angular stable screws and cables
• With angular stable plates, less invasive technique is
possible.
Platefixation
Mont et al J Arthroplasty vol 9(5) 1994
Review of litterature 1964-1991
487 patients, 26 articles
Plate fixation not as good as revision arthroplasty
I USA har det varit mycket vanligt med
kombination platta-allograft, nu visar dom
bra resultat med bara platta
Mennen plate
Not ment for rigid fixation
Space between plate and bone to not disturbe cirkulation
Results?
Cortical onlay strut allografts
Good stability
Stimulate fracture healing
Can be incorporated in host bone and increase bone mass
Create less stress-shielding than plates
Expensive, hard to get
Reduced strength of graft after 4-6 months
Initial weigh bearing not recommended
+
-
Technique
Chandler et al JBJS 79A(9) 2012, from instructional course lecture AAOS
Femur allograft best
Divide allograft in two halves
Place allograft not less than 10 cm distal to the fracture site
4 cables on each side of the fracture
Place bone graft from host at the fracture site
Full weight bearing after 3 months
Cortical allografts, results
Haddad et al JBJS 84A(6) 2002
Multicenterstudy (4 centra)
40 patients op 1992-1996
Prosthesis well fixed, no need for revision
19 patients treated with only 1 strut allograft
21 patients treated with 1 or 2 allografts and plate
27 hips revised earlier
Reduced weight bearing 3 moths
Revision of prosthesis
Cemented revision
1. Option for older patients with less physical demand
2. Option for patients with pathological fracture
3. Good and stable reposition of the fracture must be possible
before cementing the prosthesis in place.
4. Long stem needed to bypass the fracture
Revision of prosthesis
Uncemented revision with distal fixation
1. Younger patients with higher physical demands
2. Complex fractures
MP-technique for fracture cases
• Exposure easy proximal, additional osteotomy could be done
• Distal cement must be extracted
• Prophylactic cables distally
• Positioning of stem and trial reduction could be done without
reduction of the proximal fragments
• Proximal fragments fixed with cables around stem
Slutsatser
1. Majoriteten av patienter som fick en periprostetisk fraktur
hade redan en lös stam.
2. Implantat relaterade faktorer finns med överrisk för Charnley
och Exeter stammar av de cementerade.
3. Generellt dåliga resultat efter op. oavsett metod. Hög
reoperations frekvens och många komplikationer.
Slutsatser
1. B1 frakturer hade sämst resultat troligen beroende på att
stammen inte satt fast.
2. Exploration av stammen rekommenderas vid minsta tvekan
om stammen är lös. Är den ”misstänkt lös” => revidera!!
3. Mycket hög komplikationsrisk för plattfixation, troligen
beroende på att många patienter med lös protes
plattfixerades.
4. Fler infektioner vid plattosteosyntes än revision. Orsak? Fick
revisionerna mer antibiotika?