Assembling a Comprehensive List

Injuries of the lateral collateral ligament of the knee

Isolated injuries to the lateral collateral ligament of the knee are rare injuries. However, they occur more commonly in combination with other injuries and it is questionable whether they get diagnosed and appropriately treated much of the time. This list is intended to assemble the material you might need if you were going to write a review of the topic.

If you have undertaken the workshop segments on finding the best or getting a reading list you will find most of this segment is familiar. In those segments we first obtained a comprehensive list then narrowed it. This segment deals primarily with using the MeSH Browser to define the subject whereas the previous segments accomplished the same aim by other means.

Surprise! No citations were found. I almost guarentee you don't know why. It isn't because PubMed looked for the exact phrase and did not find it. To discover the reason click on Details. This should always be the first reaction if your search has unexpected results.

Scroll further down to see the "Translations" - the way PubMed interpreted the search string.

Note that PubMed confirms the search string you entered (User Query). However it has translated the request for "of the knee" as a search specifying articles from the journal "Knee". Other things to note are that "collateral ligaments" is a MeSH Term and that "injuries" can be a subheading. We will come back to the significance of this in a minute.

If you scroll up to look at the PubMed Query you will see that your seemingly innocent and straightforward query got translated into something complicated and almost unintelligible. The PubMed Query is what the search engine actually looked for.

MeSH (Medical Subject Headings) Terminology is the specialized vocabulary used by the National Library of Medicine (NLM) to define accurately what a medical article is about. The librarian at NLM do this after they receive the journal issue by looking at the article itself and the keywords. They also determine whether what type of article it is (review, case presentation, clinical trial etc) All this information is added to the citation and the most accurate way to do a comprehensive search is to use the MeSH terminology.

To look up MeSH terminology you can use the MeSH Browser.

Return to the PubMed site and click on the link to the MeSH Browser

Enter the words collateral ligaments in the text box and click on Go
	MeSH is NLM's controlled vocabulary used for indexing articles in PubMed. MeSH terminology provides a consistent way to retrieve information that may use different terminology for the same concepts.

The tree that contains the term Collateral Ligaments is displayed. Note that there are some end "twigs" which do not contain Lateral Collateral Ligament of the knee.

The default setting is "exploded" which means that if you ask for collateral ligaments you will, by default, also ask for MCL and ankle lateral ligaments. We don't want that.

Click on the link to Detailed Display

Scroll down to see the description of the term and the subheadings associated with it.

For the sake of the exercise we will restrict our search to injuries. We also only want articles in which the LCL injury is the major subject and we don't want it "exploded". Click on the check boxes until the page looks like it does below. The click on the Add box

The search is now defined in MeSH terms. Click on PubMed Search

The terms [MAJR:NOEXP] mean "major subject" and "do not explode" (good advice!). The search will now show 125 sites, but as you see many are off the subject.

We are not that interested in foals, and we want lateral ligaments of the knee.

The easiest way to accomplish this is to add the terms AND lateral AND knee to the search string

This will find 7 citations on injuries of the lateral collateral ligament of the knee

Restricting the search to injuries was done in order to practice the use of MeSH subheadings. It does detract from a comprehensive search of the subject. With the help of the limits function I constructed the search string

((("collateral ligaments"[Majr:noexp] AND lateral[All Fields]) AND ("knee"[MeSH Terms] OR knee[Text Word])) AND "human"[MeSH Terms])

In Nov 2001 this gave 18 papers, more or less on the subject. This link does that search again for you so it will be up to date for the future. (Note the complex URL!)

Summary

• Obtaining a comprehensive list of citations on a subject is best done by finding the MeSH term for that subject and using it.
• If you want only papers in which the topic is the major subject define the MeSH term as [majr]
• The granularity of MeSH terminology is quite coarse for orthopaedic subjects so you may have to narrow down the topic using Boolean logic terms, the MeSH subheadings and/or the Limits function

Myles Clough mylesclough@shaw.ca
Clinical Instructor, Department of Orthopaedics, University of British Columbia
B.C. Canada
Feedback, Comments and Questions welcome.