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Validation of a measuring technique with computed tomography for cement penetration into trabecular bone underneath the tibial tray in total knee arthroplasty on a cadaver model.

Verburg H, van de Ridder LC, Verhoeven VW, Pilot P - BMC Med Imaging (2014)

Bottom Line: The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices.CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA.Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Orthopaedics, Reinier de Graaf Groep, Reinier de Graafweg 3, 2625 AD Delft, The Netherlands. hverburg@rdgg.nl.

ABSTRACT

Background: In total knee arthroplasty (TKA), cement penetration between 3 and 5 mm beneath the tibial tray is required to prevent loosening of the tibia component. The objective of this study was to develop and validate a reliable in vivo measuring technique using CT imaging to assess cement distribution and penetration depth in the total area underneath a tibia prosthesis.

Methods: We defined the radiodensity ranges for trabecular tibia bone, polymethylmethacrylate (PMMA) cement and cement-penetrated trabecular bone and measured the percentages of cement penetration at various depths after cementing two tibia prostheses onto redundant femoral heads. One prosthesis was subsequently removed to examine the influence of the metal tibia prostheses on the quality of the CT images. The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices.

Results: Trabecular bone and cement-penetrated trabecular bone had no overlap in quantitative scale of radio-density. There was no significant difference in mean HU values when measuring with or without the tibia prosthesis. The percentages of measured cement-penetrated trabecular bone in the CT slices of the specimen were within the range of percentages that could be expected based on the measurements with the photographs (p = 0.04).

Conclusions: CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA. Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA.

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CT scan of a femoral head 3 mm beneath the cemented tibial tray. Three areas were selected, two beside the prosthesis and one posterior to the prosthesis.
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Figure 2: CT scan of a femoral head 3 mm beneath the cemented tibial tray. Three areas were selected, two beside the prosthesis and one posterior to the prosthesis.

Mentions: To assess the influence of metal tibia prosthesis on the CT images, CT scans were made of the femoral head with a tibia prosthesis in situ and once again after removal of the tibia prosthesis. Measurements were taken in the transversal slices parallel to the tibial tray. To measure the cement distribution in trabecular bone with the prosthesis in situ and without the prosthesis, three areas were selected, two beside and one posterior to the prosthesis (Figure 2).


Validation of a measuring technique with computed tomography for cement penetration into trabecular bone underneath the tibial tray in total knee arthroplasty on a cadaver model.

Verburg H, van de Ridder LC, Verhoeven VW, Pilot P - BMC Med Imaging (2014)

CT scan of a femoral head 3 mm beneath the cemented tibial tray. Three areas were selected, two beside the prosthesis and one posterior to the prosthesis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4150551&req=5

Figure 2: CT scan of a femoral head 3 mm beneath the cemented tibial tray. Three areas were selected, two beside the prosthesis and one posterior to the prosthesis.
Mentions: To assess the influence of metal tibia prosthesis on the CT images, CT scans were made of the femoral head with a tibia prosthesis in situ and once again after removal of the tibia prosthesis. Measurements were taken in the transversal slices parallel to the tibial tray. To measure the cement distribution in trabecular bone with the prosthesis in situ and without the prosthesis, three areas were selected, two beside and one posterior to the prosthesis (Figure 2).

Bottom Line: The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices.CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA.Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Orthopaedics, Reinier de Graaf Groep, Reinier de Graafweg 3, 2625 AD Delft, The Netherlands. hverburg@rdgg.nl.

ABSTRACT

Background: In total knee arthroplasty (TKA), cement penetration between 3 and 5 mm beneath the tibial tray is required to prevent loosening of the tibia component. The objective of this study was to develop and validate a reliable in vivo measuring technique using CT imaging to assess cement distribution and penetration depth in the total area underneath a tibia prosthesis.

Methods: We defined the radiodensity ranges for trabecular tibia bone, polymethylmethacrylate (PMMA) cement and cement-penetrated trabecular bone and measured the percentages of cement penetration at various depths after cementing two tibia prostheses onto redundant femoral heads. One prosthesis was subsequently removed to examine the influence of the metal tibia prostheses on the quality of the CT images. The percentages of cement penetration in the CT slices were compared with percentages measured with photographs of the corresponding transversal slices.

Results: Trabecular bone and cement-penetrated trabecular bone had no overlap in quantitative scale of radio-density. There was no significant difference in mean HU values when measuring with or without the tibia prosthesis. The percentages of measured cement-penetrated trabecular bone in the CT slices of the specimen were within the range of percentages that could be expected based on the measurements with the photographs (p = 0.04).

Conclusions: CT scan images provide valid results in measuring the penetration and distribution of cement into trabecular bone underneath the tibia component of a TKA. Since the proposed method does not turn metal elements into artefacts, it enables clinicians to assess the width and density of the cement mantle in vivo and to compare the results of different cementing methods in TKA.

Show MeSH