For the
purposes of this workshop we will pursue an interest in wrist fractures, specifically
treatment by external fixation and/or Kapandji intrafocal pinning. We will be searching
the literature using the facilities available at PubMed
Features of PubMed Overview
Note: the
boxes on the current page do not function as a search engine and are for description
only. (Comments
in red. Workshop instructions in green)
On the Basic Search page you find the following form:
Push button to start search
Selection box for the database to search
Dialog box to enter your search
string
for:
Number of documents to display per page:
Selection box for the number of citations per page
Entrez Date limit:
Selection Box for the date span to search for citations
Examine
the selection boxes by clicking on the arrows.
Note that Medline is the only
citation database of interest to the general orthopaedist. Between 10 and 5000 citations
can be posted per page. The time limit may be unlimited (default) or may be restricted to
a period between the last 30 days and the last 10 years.
Click on the
link to PubMed and
enter wrist fracture in the dialog box. Press the SEARCH button and note how many
citations are returned. 54 citations are returned on 19th July 1999. Some of these have
only the most tenuous connection with the subject of interest
Is the metatarsal fracture in postmenopausal women
an osteoporotic fracture? A cross-sectional study on 113 cases. Osteoporos Int.
1997;7(6):558-63.
PMID: 9604052; UI: 98267411.
If you read on to the 3rd page the 42nd
citation was
Comparison of eleven
external fixators for treatment of unstable wrist fractures.
J Hand Surg [Am]. 1989 Mar;14(2 Pt 1):247-54.
If you now
click on [See
Related Articles] you will find a collection of 105 articles
mostly on external fixation of wrist fractures. *Key Point*
Using the "See Related Articles" button next to an article which interests you
is the quickest and easiest way to improve the validity of your search.Why was the
initial number of articles on wrist fracture so low? One suspects that many more articles
on the subject of distal radius fracture have been written. Perhaps that is the problem,
we have been using the wrong search string (wrist fracture vs distal radius fracture).Return to PubMed and try a search for Distal Radius fracture. Use the
option to retrieve 1000 citations per page. When I did this I obtained 859 citations.
Using the browser's Edit/Find option search this page for the word Kapandji. Several
citations are found of which the following most closely match the subject of interest
[Reduction and
osteosynthesis with pin fixation of wrist fractures. A comparative study between
Kapandji's and Py's techniques].
Rev Chir Orthop Reparatrice Appar Mot. 1994;80(2):94-107. French.
[Effect of early
mobilization following Kapandji's method of intrafocal wiring in fractures of the distal
end of the radius. Results of a prospective study of 60 cases].
Int Orthop. 1992;16(1):39-43. French.
Interestingly no further
papers are found using the term "Intrafocal" as the search string. Also of
interest is the fact that Kapandji's original paper is not in the above list. This either
means that it isn't in the 859 papers on distal radius fractures, or his name wasn't first
on the list of authors, or the word Intrafocal wasn't in the title.Return
to PubMed and enter "Kapandji" as the search string. This should get all the
papers he wrote after 1967.Amongst other interesting papers note the following,
which came up on this search.
Fritz
T, et al.[See
Related Articles]
Combined Kirschner wire fixation in the treatment of Colles fracture. A prospective,
controlled trial.
Arch Orthop Trauma Surg. 1999;119(3-4):171-8.
Seifert
J, et al.[See
Related Articles]
[Studying minimally invasive osteosynthesis methods for distal radius fractures.
Intra-focal vs. conventional wire osteosynthesis].
Unfallchirurgie. 1998 Feb;24(1):18-24. German.
Epinette
JA, et al.[See
Related Articles]
Pouteau-Colles fracture: double-closed "basket-like" pinning according to
Kapandji. Apropos of a homogeneous series of 70 cases.
Ann Chir Main. 1982;1(1):71-83. English; French
Fritz
T, et al.[See
Related Articles]
[Biomechanics of combined Kirschner wire osteosynthesis in the human model of unstable
dorsal, distal radius fractures].
Chirurg. 1997 May;68(5):496-502. German.
Benoist
LA, et al.[See
Related Articles]
Buttress pinning in the unstable distal radial fracture. A modification of the Kapandji
technique.
J Hand Surg [Br]. 1995 Feb;20(1):82-96. It is very hard to
understand why some of these papers did not turn up in the previous collection.
Nonnenmacher
J, et al.[See
Related Articles]
[Intrafocal wire fixation of wrist fractures. The original Kapandji technique. Course.
Review of 400 cases].
Chirurgie. 1994-95;120(3):119-27. French.
Rayhack
JM.[See
Related Articles]
The history and evolution of percutaneous pinning of displaced distal radius fractures.
Orthop Clin North Am. 1993 Apr;24(2):287-300. Review.
Kroitzsch
U, et al.[See
Related Articles]
[Basket wires--a percutaneous surgical procedure for the treatment of unstable Colles'
fractures].
Handchir Mikrochir Plast Chir. 1991 Nov;23(6):321-6. German
Kapandji
A.[See
Related Articles]
[Intra-focal pinning of fractures of the distal end of the radius 10 years later].
Ann Chir Main. 1987;6(1):57-63. French.
One gets
the feeling that somehow the definition of the subject of interest has not been accurate
enough to pick up all the papers that Medline has. This is why NLM introduced the concept
of standardised terms to define medical subjects - the Medical Subject Heading (MeSH)
system.On
the PubMed Page find the link to MeSH Browser (MeSH Browser) Enter the term "distal radius fracture" in the box marked
"Enter a term to look up in MeSH"You will find it returns "No exact
match for your term was found. Please select from the following possibilities: " and provides a large number of possible terms. The closest match amongst
these is "Colles' Fracture". Highlight this and click on the box which says
"Browse this term" This will show you the path to the term :-
MeSH Tree Location All
MeSH Categories Diseases
Category Injuries,
Poisonings, and Occupational Diseases Wounds
and Injuries Fractures Radius
Fractures
Colles'
Fracture
What this means is that Colles' Fracture is a subset of the subject
"Radius Fractures" which in turn is part of "Fractures" and so on.
More importantly if you use the term Colles' Fracture as your search string AND define it
as a MeSH term your search will be maximally sensitive and specific. Return to the PubMed
page and enter "Colles' fracture MESH" as the search string. The number of
citations returned July 21 1999 was 484 all of which were about wrist fractures or had the
term Colles Fracture as part of the full citation. If you use the search term "Colles
Fracture" without the qualifier "MESH" I obtained 564 citations. A brief
look suggested that all the citations of the "MESH" search were included in the
second search. Disconcertingly the first citation in the second search was Fritz
T, et al.[See
Related Articles]
Combined Kirschner wire fixation in the treatment of Colles fracture. A prospective,
controlled trial.
Arch Orthop Trauma Surg. 1999;119(3-4):171-8. which we found before.
This article does NOT appear in the list of citations produced by the "MESH"
search. It may be because the NLM is still in the process of cataloging this entry.*Key
Point* Using the MeSH term and defining it as a MESH term makes the search very specific.
Using the same term but NOT defining it as a MESH term makes it more
sensitive.Unquestionably using a MeSH term will improve the quality of your search.
However, for a subject like Orthopaedics the MeSH classification is very coarse and will
result in large numbers of papers to select from. However, the site can be quite helpful
in filtering the papers.Return to the MeSH Browser and re-enter Colles' Fracture. You will see the display
Fracture of the lower end of
the radius in which the lower fragment is displaced posteriorly. Year introduced: 1991 this term to the query, using the operator . Restrict the search to the following subheadings:
blood
classification
complications
diagnosis
drug therapy economics
epidemiology
etiology
history
metabolism nursing pathology
physiopathology prevention and control
psychology
radiography radionuclide imaging rehabilitation
surgery therapy
ultrasonography
veterinary
Restrict Search to Major Topic headings only
This filter
is self-explanatory. For instance if you click on the box "Restrict Search to Major
Topic headings only" the only citations which will come up will be those in which
Colles Fracture is the major topic. If you do this you will get about 401 citations most
of which are on the subject. Even such oddities as
The Asclepiads of Dublin: a
moment in Ireland's medical history.
South Med J. 1990 Jun;83(6):664-8. No abstract available.
turn
out to be a historical account including Colles' original description! Note that the
search string used for this collection of citations was "Colles'
fracture MAJR"
When
you click on the "ADD" box you will see that the search
is now
for Current Query:
This
yielded 125 papers with high specificity to the topic.In these days of Evidence Based
Medicine a premium is placed on evidence supported by randomized controlled trials (RCTs).
PubMed reflects this trend by making it easy to find papers on your subject which are
RCTs.
From
the PubMed page click on the link to Clinical Queries You will see a page like this
Indicate the category and
emphasis below:
Category: therapy diagnosis etiology prognosis
These are so-called radio buttons. If
you click on one of them in a specific group it will be positive, all others will be
negative. For example if you click on "diagnosis" the button will be filled with
a black dot. "therapy", "etiology" and "prognosis" buttons
will be cleared.
Emphasis: sensitivity specificity
Enter subject
search (do not repeat any of the words above):
NOTE: If you want to
retrieve everything on a subject area, you should not use this page. The objective of
filtering is to reduce the retrieval to articles that report research conducted with
specific methodologies, and retrieval will be greatly reduced.
Enter the
subject "Colles' Fracture MAJR" and then click on the radio buttons
"therapy" and "specificity". (Because these belong to different groups
they do not cancel each other). In theory you have now asked for high quality papers on
the treatment of Colles' Fractures. In fact, as you will see when you click the search
button you get a collection of 14 papers on RCTs of medical treatment associated with
Colles' fractures - even though there are RCTs of surgical treatment. This is because the
search string generated by this section assumes a search for medical rather than surgical
treatment.
Note that the
search string generated by these moves is "(colles' fracture[All Fields]) AND
((double [WORD] AND blind* [WORD]) OR placebo [WORD])". Since it is highly unlikely
that any RCT in this surgical field will be double blind, or involve placebo surgery, it
is unsurprising (even though annoying) that the surgical RCTs are missed out.Now return to the PubMed Clinical Queries page and again enter Colles'
fracture as the search string, click on treatment but this time click on sensitivity
rather than specificity. The search string generated is -(Colles Fracture[All
Fields]) AND (randomized controlled trial [PTYP] OR drug therapy [SH] OR therapeutic use
[SH:NOEXP] OR random* [WORD])This leads to a collection of 75
papers, mostly about clinical trials of surgical treatment of Colles' fracture. The one
that caught my eye was
External fixation versus
percutaneous pinning for unstable Colles' fracture. Equal outcome in a randomized study of
60 patients.
Acta Orthop Scand. 1997 Jun;68(3):255-8.
Clicking on
[See
Related Articles] for this paper produced about 135 citations, most of which are
relevant to the issue.
*Key Point* Carrying out this kind of search takes persistence and
practice and refinement of your search. Computerised systems are inherently dumb and not
good at reading your mind. Your medical librarian is trained to do this for you and may be
the best resource if the quality of your search is an important issue.Boolean LogicOnce
you have gained familiarity with the PubMed system you may conclude that it just misses
formulating the question which you want to ask. What we want to find are the papers which
compare pin fixation to another method of treatment using the "gold standard"
method of evaluation - a clinical trial. Judging by previous results in this workshop the
largest selection of citations comes when you ask for "Colles' fracture" on its
own. To filter that set of citations into the set that matches our requirements we can use
the AND Boolean logic operator. If you enter "Colles' fracture and pin and clinical
trial" as the search string you will get three papers -
External fixation versus
percutaneous pinning for unstable Colles' fracture. Equal outcome in a randomized study of
60 patients.
Acta Orthop Scand. 1997 Jun;68(3):255-8.
PMID: 9246988; UI: 97389936.
External fixation or plaster
cast for severely displaced Colles' fractures? Prospective 1-year study of 46 patients.
Acta Orthop Scand. 1990 Dec;61(6):528-30.
PMID: 2281760; UI: 91127203.
*Key Point* Boolean Logic using your own terms is probably
the best way to narrow down the search to the "best" paper. However, to get an
inclusive collection of papers on the subject you will probably need to use the [See
Related Articles] feature associated with that paper.
Summary
Searches of the Medline
Database using the PubMed facility are rapid, easy and give comprehensive results.
Framing the correct search
term is the critical skill and takes practice.
PubMed has some features to
help expand your search [See Related Articles], or filter or narrow it. [Clinical
Queries]. Although these may be helpful you may prefer to use Boolean logic to frame your
own highly specific enquiry.
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