Presentation is loading. Please wait.

Presentation is loading. Please wait.

 Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common methods of treatment for joint failure.  Approximately 60 000 hospitalizations.

Similar presentations


Presentation on theme: " Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common methods of treatment for joint failure.  Approximately 60 000 hospitalizations."— Presentation transcript:

1

2  Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common methods of treatment for joint failure.  Approximately hospitalizations in Canada due to TKA s and THAs  Increase of 101% from 10 years ago [1]  Average lifetime of implant: years  Main reasons for failure of implant: › Osteolysis, Polyethylene wear, infection [2]

3

4  Due to the mechanics and constant motion of implant  Metal debris and others can be embedded in the polyethylene liners

5

6  Wears away bearing surface › Increases frictional forces  Osteolysis › Resorption of bone die to debris in joint capsule › Loosening of implant  Eventual failure

7  To quantify the amount of metal debris embedded in a polyethylene liner using micro CT › Develop a novel way of segmentation › Find possible errors and fixes for CT quantification

8  Conduct segmentation of scans using micro CT images  Analyze data through ‘Paraview’ and ‘Microview’ software.

9  Using X-ray CT technology, third-party debris can be segmented from the polyethylene portions of a retrieved component

10  Polyethylene components were surgically retrieved from failed TKR and THR  Specimens were pre-screened to have known third party debris  Scanned using Micro CT

11  Used Histogram to qualitatively set threshold levels  Microview takes threshold levels and creates isosurface  Using calibrated data from the scanner, the amount of voxels is converted into a volume  By making 2 surfaces: Polyethylene and Metal, the volume of the two are calculated.

12

13  No other benchmark to compare to  Therefore cannot quantitatively compare volume sizes  Visually inspect to qualitatively validate volume data  Volume data with visible artifacts are also rejected

14

15

16

17

18

19 Specimen IRAL Number Volume at Threshold 250 (mm^3) Volume at Threshold (mm^3)Comments K K K Showed no metal, but non-zero metal in MIP K K K Outer artifact

20  Of the 11 specimens scanned:  5 hip poly and 6 knee poly  2 Hips polys and 2 Knee polys had anomalies

21 Specimen IRAL Number Volume at Threshold 250 (mm^3) Volume at Threshold (mm^3)Comments K K K Showed no metal, but non-zero metal in MIP K K K Outer artifact

22

23

24  X-ray CT can be a valid method of analyzing amount of metal debris in a retrieved poly  7 of 11 polys measured without artifacts  The other 4 with artifacts are easily removed manually

25  The effect of outer artifacts on the volume measured inside  Methods of reducing artifacts

26  Metal Debris can be quantified using micro CT method  Caution must be used to pre-screen images for artifacts before accepting results  Novel non-invasive way of determining volume

27  Matt Teeter Ph.D.c  Lyndsay Sommerville Ph.D.c

28 1) Bohm, E., M. J. Dunbar, et al. (2009). "The Canadian Joint Replacement Registry— what have we learned?" Acta Orthopaedica 81 (1): ) Hayashi, A. (2009). "Modes of failure can predict outcomes after revision TKA " American Academt of Orthopaedic Surgeons News.

29 Question Period


Download ppt " Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common methods of treatment for joint failure.  Approximately 60 000 hospitalizations."

Similar presentations


Ads by Google