This appears to be a subset of "migration". I gather it is when the screw "strips" the threads it has formed in the bone. Another form of "migration" appears to be "backing out" which presumably is when the screw "loosens" by turning in the threads.

cat.inist.fr/?aModele=afficheN&cpsidt... - Translate this page
by PL DOCQUIER - 2002 - Cited by 40 - Related articles
Les deux complications majeures les plus fréquentes ont été le BALAYAGE (CUT OUT ) DE LA VIS CÉPHALIQUE (7,1%) et les fractures diaphysaires (3,1%). Les autres ...

.elsevier.com/retrieve/pii/S0748798304002008
by SR Samsani - 2004 - Cited by 11 - Related articles
Another patient had CUTOUT OF CEPHALIC SCREW into the hip joint. However, the patient remained minimally symptomatic due to low functional demand. The third ...

www.springerlink.com/index/VMJRBT820YR3PNLX.pdf
by F Chevalley - 2001 - Cited by 3 - Related articles
tial to achieve GOOD FIXATION OF THE CEPHALIC SCREW, THUS REDUCING THE RISK OF CUTOUT. To avoid reaming, surgical compromise may favor slightly insufficient insertion ...

JBJS | Displacement/Screw Cutout After Open Reduction and ...
www.jbjs.org/cgi/reprint/90/2/233.pdf
by C Kevin - 2008 - Cited by 109 - Related articles
1 Feb 2008 – As would be expected, when the fracture settled the SCREWS CUT OUT. We would contend that had the fracture been reduced, this outcome might ...

www.ncbi.nlm.nih.gov/pubmed/14676555
by M Szpalski - 2004 - Cited by 29 - Related articles
Cement augmentation of HIP LAG SCREWS TO AVOID CUT-OUT DISPLACEMENT is classically described, along with a number of technical drawbacks. In a series of six ...

www.mybrokenleg.com/faq/glossary.html
29 Dec 2001 – The pins, plates, rods or SCREWS CUT OUT, break, bend or pull out before the fracture heals. This is commoner when union is delayed and almost ...

www.mtdesk.com/Sample orthopaedic - hip arthroplasty and OR...
26 Oct 2011 – Medical terms, terminology, transcription samples and words ... Open reduction and internal fixation greater trochanter fracture. ... Her SLIDING HIP SCREW HAD CUT OUT OF THE FEMORAL HEAD and was abrading the acetabular surface. ...

’CUT-OUT’ OF THE IMPLANT proximally (penetration of the implant from the proximal femur either into the hip joint or external to the femur). [ ... ] These comprised 20 breakages at the nail-plate junction and five cases of ’CUT-OUT’.Hornby 1989 reported only five minor complications consisting of three cases of MIGRATION of the lag screw in the femoral head without penetration into the hip joint and two instances of BACKING OUT of the screw, both in one person. [ ... ] Fracture fixation failure (reoperation, SCREW MIGRATION, CUT-OUT)
http://www.thecochranelibrary.com/userfiles/ccoch/file/CD000...



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Note added at 21 hrs (2011-12-27 17:23:23 GMT)
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www.ncbi.nlm.nih.gov › Journal List › Int Orthop › v.30(5); Oct 2006
by AJS Kumar - 2006 - Cited by 4 - Related articles
6 May 2006 – CUT-OUT can be defined as collapse of the neck-shaft angle into the varus, leading to extrusion of the screw from the femoral head [2]. ...

Descriiption here you medical people might understand:
http://books.google.fr/books?id=ZG6h3ESiZbcC&pg=PA152&lpg=PA...

www.amub.be/rmb/download_pdf.php?... - Translate this page
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by I Berkenbaum - 2004 - Related articles
Un BALAYAGE DE VIS CÉPHALIQUE (GLISSEMENT DE LA VIS CERVICALE PAR RAPPORT À LA PLAQUE), correspondant au deuxième cas de la série, et un descellement


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Note added at 21 hrs (2011-12-27 17:36:32 GMT)
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www.ncbi.nlm.nih.gov › Journal List › Int Orthop › v.30(5); Oct 2006
by AJS Kumar - 2006 - Cited by 4 - Related articles
6 May 2006 – CUT-OUT can be defined as collapse of the neck-shaft angle into the varus, leading to extrusion of the screw from the femoral head [2]. ...

Descriiption here you medical people might understand:
http://books.google.fr/books?id=ZG6h3ESiZbcC&pg=PA152&lpg=PA...

www.amub.be/rmb/download_pdf.php?... - Translate this page
File Format: PDF/Adobe Acrobat - Quick View
by I Berkenbaum - 2004 - Related articles
Un BALAYAGE DE VIS CÉPHALIQUE (GLISSEMENT DE LA VIS CERVICALE PAR RAPPORT À LA PLAQUE), correspondant au deuxième cas de la série, et un descellement

Some pictures here but they don't help me ascertain if the screw works loose axially or breaks through the bone radially ...

http://www.hopkinsmedicine.org/gec/series/fixing_hip_fractur...

Accurate placement of the lag screw is one of the strongest predictors of whether or not the LAG SCREW WILL PULL OUT OF THE FEMORAL HEAD (CUT-OUT) and result in implant failure
http://www.ncbi.nlm.nih.gov/books/NBK32595/

Ah! There's a nice X-ray here of "proximal screw cutout" showing the screw displaced radially.
http://books.google.fr/books?id=MDzd6Z_qCdcC&pg=PA472&lpg=PA...


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Note added at 1 day3 hrs (2011-12-27 23:50:51 GMT)
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OK, this is mon dernier mot, now that I've ascertained to my own satisfaction that cutout is radial displacement of the screw.

Toutefois, quelques fractures tardent à consolider, entraînant une sollicitation importante des interfaces vis-os et se soldant par des ruptures ou arrachements de vis, ou par un BALAYAGE PROGRESSIF DE L'OS DE LA TÊTE par la grosse vis céphalique.
http://revue.medhyg.ch/print.php3?sid=21644

In the X-ray here - http://www.maitrise-orthop.com/viewPage.do?id=892 – the screw seems to have moved both radially and axially.

The most common failure mechanism is migration of the femoral head into varus and retroversion, and subsequent extrusion, OR SO-CALLED CUTOUT, of the lag screw through the femoral head.
[ ...]
FIGURE 3. Dynamic hip screw CUTOUT (A) on patient x-ray, (B) in surrogate foam, and (C) in cadaveric specimen. [figures show radial displacement of the screw]
http://www.biomechresearch.org/Publications/14 A Laboratory ...