These can be actual objects or virtual, in the case of computer-assisted pre-operative planning.

Digital Templating and Preoperative Deformity Analysis with ...However, the emphasis of their study was not on preoperative planning and/or the use of the overlay template technique discussed in this article. ...
www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2745458 - Similar -
by AA Jamali - 2009 - Related articles
Orthocrat - Preoperative Planning Solutions24 Feb 2005 ... TraumaCad Orthopedic Planning Software and Pre-Operative ... used acetate overlays and radiographs to determine appropriate implant size. ...
www.ortho-cad.com/b/Content/Technology_2_2.html



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Note added at 8 hrs (2009-10-29 07:53:21 GMT)
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From the first link:

Analysis of deformity and subsequent correction are the basis for many orthopaedic surgical procedures. In advanced cases of joint degeneration, arthroplasty may be the only available treatment option. Until recently, these analyses and preoperative surgical plans have been performed using standard radiographs, tracing paper, and/or plastic overlays. Numerous customized, commercially available, computer-based preoperative planning software programs have been introduced.

The way the ST is worded, it doesn't sound like these "calques" are digital.

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Note added at 8 hrs (2009-10-29 08:25:41 GMT)
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IOW these are neither virtual not solid medical models.

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Note added at 11 hrs (2009-10-29 11:17:43 GMT)
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Yes, that's what they are. The surgeon superimposes the templates/overlays on the X-rays to select the size of the implant and guide decisions about positioning.