MODELING AND SIMULATION OF A HIP PROSTHESIS IMPLANTATION

We studied the role of cytokines (TNF-α, IL-6,IL-1β, TGF-β) as markers of osteolysis in patients who underwent to a hip prosthesis implantation subdivided in two groups: group A with an ultrahigh molecular weight polyethylene (UHMWPE) insert articulating against a metal ball head , and group B with an all alumina ceramic combination. Profibrogenic (TGF-β) and pro-inflammatory cytokines (TNF-α, IL-6,IL-1β) are secreted by the periprosthetic synovial-like fibrous membrane in hip artificial implants. They are secreted by inflammatory activated cells and trigger the cascade of biochemical events leading to the activation of osteoclasts and bone resorption. A statistically significant increase of TGF-β serum levels was observed between TGF-β values in implanted patients as compared to normal subjects and between TGF-β values after versus before implantation in Group A. A progressive decrease in TNF-α and IL-6 serum levels has been observed in both Groups, when compared with the initial values before the implantation. IL-1β levels decreased up to 60 months after the implantation Our data suggest that monitoring circulating cytokines could be a good indicator for the proliferation and activity of the periprosthetic synovial-like membrane and potential osteolysis. This could allow for an adequate early treatment.

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99mTc-labeled ubiquicidin scintigraphy

Nuklearmedizin ◽

10.3413/nukmed-0444-11-11 ◽

2012 ◽

Vol 51 (04) ◽

pp. 133-139 ◽

Cited By ~ 13

Author(s):

K. Aryana ◽

A. Hootkani ◽

R. Sadeghi ◽

Y. Davoudi ◽

M. Naderinasab ◽

...

Keyword(s):

Bone Scan ◽

Hip Prosthesis ◽

High Sensitivity ◽

Final Diagnosis ◽

Predictive Values ◽

Bacterial Colony ◽

Hip Prostheses ◽

Hip Prosthesis Implantation ◽

Sensitivity Specificity ◽

Painful Hip

SummaryAim: Hip prosthesis implantation has witnessed a significant increase in recent years. Despite the advantages of this surgical procedure, it has some complications, the most serious of which is prosthetic infection. This study was conducted to investigate the feasibility of 99mTc-UBI scintigraphy in detection of infectious foci in painful hip prosthesis. UBI (Ubiquicidin 29–41) is an antimicrobial peptide fragment with the ability to target the bacterial colony directly. Patients, methods: 34 patients, aged 20–79 years, with painful hip prosthesis were included. 99mTc-UBI scan and three phase bone scan were performed and two nuclear medicine specialists interpreted the UBI scans with and without bone scan results at hand. Both qualitative and semiquantitative methods were used to interpret the 30 minute post injection images. The patients were actively followed up. According to the surgical findings, microbiological culture and active follow up, final diagnosis was made. Results: 24 negative and 10 positive UBI scans were recorded. The sensitivity, specificity, negative and positive predictive values and accuracy of the study were all 100%. Bone scan did not have any influence on UBI interpretation. We were able to achieve excellent differentiation between infected and non-infected prostheses with a cut off value of 1.8 for target to non target (T/NT) ratio. No adverse effects were noticed following UBI scan. Conclusion: Based on the findings, the authors believe that 99mTc-UBI scintigraphy, with its high sensitivity and specificity, provides the physician with an excellent tool for differentiating infection from aseptic loosening of hip prostheses. Using this radiopharmaceutical, it is possible to obtain highly accurate results only 30 minutes after the beginning of the study.

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Novel methods for demonstrating osseointegration of hydroxylapatite-coated titanium hip prostheses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084478 ◽

1991 ◽

Vol 49 ◽

pp. 34-35 ◽

Cited By ~ 1

Author(s):

P. Frayssinet ◽

J. Hanker ◽

D. Hardy ◽

B. Giammara

Keyword(s):

Hip Prosthesis ◽

Ethanol Concentration ◽

Bone Matrix ◽

Electron Microscopic Examination ◽

Electron Microscopic ◽

Hip Prostheses ◽

Cellular Inclusions ◽

Microscopic Studies ◽

Diamond Saw ◽

Plasma Sprayed

Prostheses implanted in hard tissues cannot be processed for electron microscopic examination or microanalysis in the same way as those in other tissues. For these reasons, we have developed methods allowing light and electron microscopic studies as well as microanalysis of the interface between bone and a metal biomaterial coated by plasma-sprayed hydroxylapatite(HA) ceramic.An HA-coated titanium hip prosthesis (Corail, Landos, France), which had been implanted for two years, was removed after death (unrelated to the orthopaedic problem). After fixation it was dehydrated in solutions of increasing ethanol concentration prior to embedment in polymethylmethacrylate(PMMA). Transverse femur sections were obtained with a diamond saw and the sections then carefully ground to a thickness of 200 microns. Plastic-embedded sections were stained for calcium with a silver methenamine modification of the von Kossa method for calcium staining and coated by carbon. They have been examined by back-scatter SEM on an ISI-SS60 operated at 25 KV. EDAX has been done on cellular inclusions and extracellular bone matrix.

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