cadera / hip - Active Congress.......

MIÉRCOLES / WEDNESDAY
140
8. Vascular Exam
9. Psychological Analysis
C. Laboratory Analysis
1. GOAL: Differentiate Septic From Aseptic
Cause
2. Hematology
a) CBC With Differential
• Little Value If Used Alone
• Left Shift Suggestive of Sepsis
• Use In Combination With ESR/ CRP
b) Erythrocyte Sedimentation Rate
(ESR)
• Normally Increased For 3-6 Months
Postoperatively
• Infection Sensitivity: 73-100%
• Infection Specifi city: 69-94%
• Diagnostic Accuracy: 73-88%
c) C-Reactive Protein (CRP)
• Normally Returns To Normal By 3
Weeks Postoperatively
• Sensitivity/ Specifi city – Similar To
ESR
d) ESR + CRP Enhances Accuracy
• 100% Sensitivity/ Specificity (K.
Garvin, AAOS, 1996)
3. Hip Aspiration – Questionable Reliability
a) Sensitivity: 40-91%
b) Specifi city: 60-100%
c) False Positive Rates: 16-30%
D. Radiographic Evaluation
1. Plain Radiographs: Loosening Criteria
a) Component Migration
b) Progressive/ Complete Radiolucent
Lines > 2 mm
c) Cement Mantle Fracture
d) Divergent/ Complete Radiosclerotic
Lines With Distal Femoral Pedestal
(Cementless Femoral Component)
2. SERIAL Radiographic Evaluation Valuable
Study Acetabulum Femur
Sensitivity Specifi city Accuracy Sensitivity Specifi city Accuracy
O’Neill & Harris, JBJS 1984 37% 63% 54% 89% 92% 91%
Lyons et al, CORR 1985 63% 89% 69% 76% 100% 84%
Hendrix et al, Radiology 1983 43% 100% 60% 79% 100% 85%
3. Hip Arthrography
a) Valuable In Cemented THA
b) Accuracy < 65% In Cementless THA
• Barrack, et al, Skeletal Radiology,
1994
c) Accuracy Enhanced By:
• High Injection Pressure
• Post-Ambulation Films
• Digital Subtraction Technique
d) Literature Review:
Acetabulum
Sensitivity 38-95%
Specifi city 68-100%
Accuracy 60-90%
Femur
Sensitivity 38-96%
Specifi city 50-100%
Accuracy 83-93%
e) Nuclear Arthrography
• Best For Femoral Component
• Sensitivity: 64-93%/ Specifi city: 75-
100%
4. Nuclear Medicine Scans
a) Technitium – 99m – HDP (99mTc)
• High Sensitivity/ Low Specifi city
• Prolonged ↑ Uptake Normal After
THA (Cemented:6-12 Months/
Cementless: 2 Years)
b) Gallium Citrate
• Localizes In Areas of WBC Accumulation
& Infl ammation
• Low Specifi city If Used Alone
• Best If Combined With 99mTc (60-
80% Accuracy)
c) WBC Indium – 111
• Widely Variable Results
• Sensitivity: 50-100%/ Specificity:
23-100%