THA Flashcards
cane in what hand to decresae joint reactive force
contralateral hand, you are pushing the body weight up to decrese the force the abductors have to work.
carrying loa din ipsilateral side decreases joint reactive force why
it is pulling gainst bodyweight, abductors dont have to work as hard
risk factors for THA wear
thickness <6 mm
malalignment of components
patients <50 y/o
men
higher activity level
femoral head size and wear
need a paper
UHMWPE is cross linked
No, all poly is UHMWPE, cross linking is separate, gamma rays
Factors increasing wear in THA
<6 mm thickness, malalignment of components, patients <50 yrs, men, higher activity levelC
Ceramic on poly wear rate
0-.15 mm/year
ceramic on ceramic wear rate
.5 to 2.5 micron/year
titanium bearing surfaces
bad, poor resistance to wear and notch sensitivityD
Does titanium ions lead to issues?
…..
ALVAL
Aseptic lymphocyte dominant vasculitis associated lesion (pseudotumor)
ALTR
Adverse Local Tissue Reaction
Treatment for blow out abductors
Gluteus maximus transfer
which cell type causes osteolysis
macrophage activated by polyethylene debris
cytokines of osteolysis
TNF alpha is the key, TNA alpha increases RANK and RANK Ligamend mediated bone resorption
volumetric wear and highly cross linked poly
Volumtric wear initially concerning however modern highly crosslinked has shown similar wear rates between different head sizes
Head size and wear rates
22-46 mm head size does not influence wear rates of UHMWPE
study for head size and wear rates
Journal of Arthroplasty 2001 by Muratoglu
most important type of wear for osteolysis
adhesive wear
how to measure osteolysis and wear pattersn
radiostereometric analysis, tantulum beans in the bone
how to prevent HO formation
indomethacin x10 days to 6 weeks vs. 600-800 cGy within 24-48 hours after procedure
Dislocation incidence in all THA
1-3%
Dislocation after THA when does it happen
70% within the first month, most within 3 months
Direction of most dislocations
75-90% posterior
how to dislcoate anterio rand posterio
posterior is flex/add/IR, eanterior is ext/ER
risk factors for dislcoation
prior hip surgery, more comorbidities, BMI <20 or >35, cemented, posterior hip approach, malpositioning of components!!!!, neuromuscular disease like Parkinson’s, drug or alcohol abuse, decreased head neck ratio, decreased femoral offset, spinal fusion or fixed spinopelvic alignment. POLY WEAR IS A COMMON CAUSE OF LATE INSTABILITY >5 YEARS POST procedure.
when to revise for dislocation
2 or more dislocations with implant malaligment, failure, or poly wear
indicaitons for a constrained liner
abductor deficiency
which THA approaches has most risk for HO
Smith Petersen and Hardinge (Posteiror has lowest risk for HO)
HO markers
elevated alkaline phosphatase
Risks for Direct anterior approach
LFCN, superficial surgical site infection riskt
trunnoinosis type of wear
crevice corrosion is most important
treatment for trunnionosis
painful THA, synovectomy, inspect stem, if you can retain it ceramic with titanium sleeve and new poly liner
trunnionosis with Ceramic on Ti
A study from Montreal showed that Ceramic on titanium stem showed no radiological or biological signs of trunnionososis and Ti ion levels were bleow the accepted range
implanting on a trunnion
The trunnion should be rinsed, cleaned, and dried carefully, while avoiding any contamination of the bore—the female counterpart within the head—prior to assembly. Biological debris, and even residual water, might critically reduce the fixation of the taper connection between the head and the neck.
Reduced mortality associated to cementless total hip arthroplasty in femoral neck fracture
Corentin Pangaud, Vanessa Pauly, Christophe Jacquet, Veronica Orleans, Laurent Boyer, Raghbir Khakha, Jean Noël Argenson & Matthieu Ollivier
Scientific Reports volume 1
After multivariate analysis including age and comorbidities, patients who underwent surgery after 72 h intra-hospital had a higher risk of mortality: . Hazard Ratio (HR) = 1.119 (1.056–1.185) p = 0.0001 compared to the group who underwent surgery within 24 h. THA was found to be a protective factor HR = 0.762 (0.731–0.795) p < 0.0001. The use of cement was correlated with higher mortality rate: HR = 1.107 (1.067–1.149) p < 0.0001. Three key points are highlighted by our study in the reduction of mortality related to femoral neck fracture: the use of hemiarthroplasty a surgery performed after 48 h and the use of cement for femoral stem fixation adversely affect mortality risk.
Anterior THA benefits
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Should have arguemnt to support antibiotiocs for wound drainage for DAA wound…
when to worry about metal on poly
when it is > 1 ppb
Fracture rate cemented vs. unceemented hemis
10x higher fractur rate???
