PubMed 1. Basic - Calcaneo-navicular bar

This is the first in a series of mini-workshops on the subject of using PubMed, the public Internet interface to the US National Library of Medicine (NLM) Medline database. For this introduction we are going to pursue the subject raised by Dr Harpal Singh Selhi; pain and swelling of the ankle in a 17 year old soccer player whose Xrays show evidence of a calcaneo-navicular bar.

This workshop is overly simple for those who are used to using PubMed. It is basic and is aimed at people who rarely use the site. More complex functions of the site will be examined in future workshops.

The Medline computer database was started in 1967 and consists of citations, abstracts and subject classification information for all published articles in thousands of medical and bioscience journals including over 100 orthopaedic journals. PubMed is a search engine which allows this database to be searched via an Internet interface. It is important to understand some of the limitations - only abstracts are online at the site, not full text; there are many orthopaedic journals which are not indexed in Medline (example, the Bulletin of the AAOS); textbooks and the Internet are not searched by PubMed; and an important part of the system, classification of subject matter is done by librarians, not orthopaedic surgeons. For these reasons, a PubMed search may not be as complete or accurate as you might like.

Another cause for concern is that PubMed searches commonly return hundreds or thousands of citations, making it very difficult to identify the material you would like to examine more fully, and even more difficult to be sure that you have done a comprehensive search. These workshops are designed to identify the processes involved in conducting a search, to describe the more valuable features of the site and to formulate strategies which will make searching more satisfying.

PubMed address.

The easiest URL to remember is However, this address forwards you to which is probably the one to bookmark. Open the site and type the subject (calcaneo-navicular bar) into the search box. Then click on Go

The list of citations is disappointing. There are only two articles listed, both are nearly 40 years out of date and neither have an abstract which would allow us to get an idea of the contents. We will examine why this is a poorly chosen search string at the end of this workshop.

Items 1 - 2 of 2

One page.
1: Mitchell GP, Gibson JM. Related Articles, Links
Excision of calcaneo-navicular bar for painful spasmodic flat foot.
J Bone Joint Surg Br. 1967 May;49(2):281-7. No abstract available.
PMID: 6026513 [PubMed - indexed for MEDLINE]
2: BEALE G. Related Articles, Links
J Coll Radiol Australas. 1963 Oct;42:202-5. No abstract available.
PMID: 14074372 [PubMed - OLDMEDLINE for Pre1966]

However, all is not lost. Beside each citation is a link to "Related Articles". These are articles in the Medline database which have a subject classification (entered by the librarians) close to the subject classification of the original article. So if an article in 1967 was classified as being on the subject of flatfeet all subsequent articles which are classified similarly will be "Related". To see how the index article has been classified you can change the display from the default (Summary) to "Citation"

1: J Bone Joint Surg Br. 1967 May;49(2):281-7. Related Articles, Links

Excision of calcaneo-navicular bar for painful spasmodic flat foot.

Mitchell GP, Gibson JM.

MeSH Terms:
  • Adolescent
  • Child
  • Child, Preschool
  • Female
  • Flatfoot/radiography
  • Flatfoot/rehabilitation*
  • Flatfoot/surgery*
  • Follow-Up Studies
  • Humans
  • Male

PMID: 6026513 [PubMed - indexed for MEDLINE]

Schmied HR.

MeSH Terms:
  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Female
  • Flatfoot/radiography
  • Flatfoot/surgery*
  • Follow-Up Studies
  • Humans
  • Male
  • Methods
  • Middle Aged
  • Occupations
  • Postoperative Care
  • Preoperative Care
  • Tendons/surgery
  • Time Factors
The list of MeSH terms (above) includes three on flatfoot. The two terms marked with an asterisk * are the major subjects of the article. MeSH stands for Medical Subject Heading and is the vocabulary used by NLM librarians to describe the contents of articles. Click on the link to Related Articles You will see a much more promising collection of 144 articles (below). If you look at the citation of the second article (left) you can see that it is indeed classified in a very similar fashion to the first.

Items 1 - 20 of 144

1: Mitchell GP, Gibson JM. Related Articles, Links
Excision of calcaneo-navicular bar for painful spasmodic flat foot.
J Bone Joint Surg Br. 1967 May;49(2):281-7. No abstract available.
PMID: 6026513 [PubMed - indexed for MEDLINE]
2: Schmied HR. Related Articles, Links
[Late results in the management of flatfoot through navicular translocation]
Z Orthop Ihre Grenzgeb. 1968 Apr;104(3):309-17. German. No abstract available.
PMID: 4233338 [PubMed - indexed for MEDLINE]
3: Kiter E, Gunal I, Turgut A, Kose N. Related Articles, Links
Evaluation of simple excision in the treatment of symptomatic accessory navicular associated with flat feet.
J Orthop Sci. 2000;5(4):333-5.
PMID: 10982680 [PubMed - indexed for MEDLINE]
4: Sullivan JA, Miller WA. Related Articles, Links
The relationship of the accessory navicular to the development of the flat foot.
Clin Orthop Relat Res. 1979 Oct;(144):233-7.
PMID: 535230 [PubMed - indexed for MEDLINE]
5: Villani C, Chiozzi F, Persiani P, Costantini A. Related Articles, Links
Flat foot: a comparison of surgical methods.
Chir Organi Mov. 2003 Jan-Mar;88(1):49-55. Review. English, Italian.
PMID: 14584316 [PubMed - indexed for MEDLINE]

However, although there are more articles in this list and more recent ones, we see that many of them are about flatfeet in general, not tarsal coalition. The best plan is to go down through the list until you find an article which is relatively recent and exactly on the subject. I selected # 19 from the title and from the fact that it is an article in the JAAOS which is accessible online to all Fellows and International Members of the AAOS. Since membership also gets you free admission to the annual meeting and a free practice website this is one of the all-time bargains in academic orthopaedics. I read this article and it is an excellent review and summary of the problem. He advocates excision of the calcaneo-navicular bar and interposition of extensor digitorum brevis muscle to prevent recurrence. (80% good outcomes)

The author name line is a link to a page displaying the abstract of that article.

J Am Acad Orthop Surg. 1998 Sep-Oct;6(5):274-81. Related Articles, Links
Tarsal coalition and painful flatfoot.

Vincent KA.

Shriners Hospital for Children, Portland, Oregon and Department of Orthopedics, Oregon Health Sciences University, Portland, OR 97201-3905, USA.

The prevalence of tarsal coalition is probably 1% or less. The two sites most commonly affected are the calcaneonavicular joint and the middle facet of the talocalcaneal joint. Diagnosis should be suspected in the preteen or teenage patient with insidious or sudden onset of pain in the midfoot to hindfoot associated with a lack of motion in the subtalar joint. Initial treatment with immobilization or an orthosis may relieve symptoms, but most patients will have persistent symptoms that warrant surgical correction. Long-term results indicate that excision of the coalition is moderately successful in relieving symptoms in the calcaneonavicular bar. Long-term success with excision of subtalar bars is less clear, although early relief of symptoms is usually possible.

Publication Types:
  • Review
  • Review, Tutorial

Now that we are satisfied that this is an article which is on subject and up to date we can expand the search repeating the use of the "Related Articles" link. This gives you a much longer list (over 300) and all of the first 20 appear to be on subject. If our object with this basic search was to find something about the topic we have been successful

(See the whole page)

Items 1 - 20 of 310


 of 16

1: Vincent KA. Related Articles, Links
Tarsal coalition and painful flatfoot.
J Am Acad Orthop Surg. 1998 Sep-Oct;6(5):274-81. Review.
PMID: 9753754 [PubMed - indexed for MEDLINE]
2: Cowell HR, Elener V. Related Articles, Links
Rigid painful flatfoot secondary to tarsal coalition.
Clin Orthop Relat Res. 1983 Jul-Aug;(177):54-60.
PMID: 6861407 [PubMed - indexed for MEDLINE]
3: Bohne WH. Related Articles, Links
Tarsal coalition.
Curr Opin Pediatr. 2001 Feb;13(1):29-35. Review.
PMID: 11176240 [PubMed - indexed for MEDLINE]
4: Bhalaik V, Chhabra S, Walsh HP. Related Articles, Links
Bilateral coexistent calcaneonavicular and talocalcaneal tarsal coalition: a case report.
J Foot Ankle Surg. 2002 Mar-Apr;41(2):129-34.
PMID: 11995834 [PubMed - indexed for MEDLINE]
5: Stormont DM, Peterson HA. Related Articles, Links
The relative incidence of tarsal coalition.
Clin Orthop Relat Res. 1983 Dec;(181):28-36.
PMID: 6641062 [PubMed - indexed for MEDLINE]
6: Collins B. Related Articles, Links
Tarsal coalitions. A new surgical procedure.
Clin Podiatr Med Surg. 1987 Jan;4(1):75-98. Review.
PMID: 2949819 [PubMed - indexed for MEDLINE]
7: Rouvreau P, Pouliquen JC, Langlais J, Glorion C, de Cerqueira Daltro G. Related Articles, Links
[Synostosis and tarsal coalitions in children. A study of 68 cases in 47 patients]
Rev Chir Orthop Reparatrice Appar Mot. 1994;80(3):252-60. French.
PMID: 7899645 [PubMed - indexed for MEDLINE]

There is a clue here about why our initial search was disappointing. "Tarsal coalition" is used commonly in these articles, the word "calcaneonavicular" more rarely and "calcaneo-navicular" very rarely. The computer robot is very literal and doesn't "know" that these terms are the same unless someone in the NLM has told it so. We would have done better to use tarsal coalition as the initial search string. As we go further into this subject we can see that using standard terminology to define your subject has even more definite advantages.

Why did the related articles link on Vincent's article yield a better collection than "related links" for the original 1967 Mitchell and Gibson article? The reason is that the librarians introduced a new classification term, Foot Deformities, Congenital in 1988. Vincent's article was classified under that subject as well as flatfeet giving a more accurate description of the subject. This is the reason I suggest using the most relevant and the most up to date article you can find, for the "Related Articles" link.

PubMed is not the only database that can be searched. PubMed Central (PMC) is a database of articles of which the full text is available for free. Unfortunately very few orthopaedic articles are published in journals which make the full text available in this way. If you search PMC for tarsal coalition there are no articles. A search for the MeSH term foot deformities, congenital yields two papers, both on genetics.

Summary for basic steps using PubMed

  1. Enter your subject in the search box on PubMed (
  2. If no suitable articles are found, adjust your search string and enter another commonly used synonym. You must be prepared to iterate when you use search engines.
  3. Find an article on subject and look at the abstract. Keep doing this until you find an article which is on subject and up to date.
  4. If that is not enough, click on the Related Articles link to find more articles which are on the same subject.
  5. Refining the search beyond finding "something" is the subject of future workshops

Please submit any comments and discussion of this to the orthopod list. We will let any discussion of this workshop die down before going on to the next. Indeed if there is no discussion and no one urges me to continue, I won't.

Other workshops in this series

Myles Clough