Test library › Foot, ankle & calf
Ottawa foot rules
For: Midfoot fracture after an ankle or foot injury (need for X-ray)
Website-only page: no separate test card in the book, which discusses this in its ‘The ankle and foot’ chapter.
A break of a midfoot bone, such as the base of the fifth metatarsal or the navicular, after an injury. The Ottawa foot rules decide who needs an X-ray; they do not diagnose the fracture.
Best used to rule outLR+ calculated from the pooled sensitivity and the median specificity, so it is approximate; LR− as pooled in the review.
These figures have not been confirmed against the full paper (checked against the abstract or a secondary source only).
How it is done
For a patient with pain in the midfoot zone after an acute injury. A foot X-ray is needed if ANY of these is present: (1) bone tenderness at the base of the fifth metatarsal; (2) bone tenderness at the navicular; (3) unable to bear weight for four steps both immediately after the injury and at the time of assessment. If none is present, no X-ray is needed.
What the studies found
Decision rule for foot X-ray — a rule-out tool. A negative rule makes a midfoot fracture very unlikely; a positive rule means 'X-ray', not 'fracture' (LR+ about 1.6). Bachmann et al. 2003 (systematic review, 27 studies, 15,581 patients): pooled sensitivity 99% (95% CI 97.3–100%) and LR− 0.08 (95% CI 0.03–0.20) for the midfoot. Specificity was not pooled; 37.8% is the median across studies (interquartile range 24.7–70.1%). Only 13 of the 27 pooled studies X-rayed every patient. A later meta-analysis (Barelds 2017) pooled LR− 0.14 for the combined ankle-and-foot rules. Usually applied together with the Ottawa ankle rules.
What the numbers mean
- Positive result: barely informative: a positive result changes little.
- Negative result: a strong rule-out: a negative result makes the diagnosis very unlikely.
The ladder: what a result does to your estimate
| If you thought | After a positive | After a negative |
|---|---|---|
| 10% | 15% | under 1% |
| 30% | 41% | 3% |
| 50% | 61% | 7% |
Calculated from the likelihood ratios above. For any other starting estimate, use the probability calculator.
Work out what a result means for your patient: probability calculator
Source
Bachmann LM, Kolb E, Koller MT, Steurer J, ter Riet G. Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review. BMJ. 2003;326(7386):417. Review summary (NCBI Bookshelf) · systematic review
Also cited: Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992;21(4):384–390. Journal article (DOI)
Also cited: Stiell IG, Greenberg GH, McKnight RD, et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA. 1993;269(9):1127–1132. PubMed
Also cited: Barelds I, Krijnen WP, van de Leur JP, van der Schans CP, Goddard RJ. Diagnostic accuracy of clinical decision rules to exclude fractures in acute ankle injuries: systematic review and meta-analysis. J Emerg Med. 2017;53(3):353–368. Journal article (DOI)
Website-only page, added to the library on 9 October 2026. Rule It In, Rule It Out discusses this but has no separate test card for it. Figures independently checked against the sources cited above; any note above says where only the abstract could be checked.
Get the book for spotting a high ankle sprain, and knowing when the Achilles is torn
The ‘The ankle and foot’ chapter of Rule It In, Rule It Out discusses this, alongside how to do and read each test in the chapter.
Coming in late 2026 as a PDF and a paperback. Join the list to hear when it's out
One study, one test, once a month
Rule It In is a free evidence letter for musculoskeletal clinicians: one recent study explained, one examination test with its real numbers. From Trokos, publisher of Rule It In, Rule It Out.
Free when you confirm your email: a one-page PDF of the strongest special tests to rule in and rule out, with tests that carry a caution flagged separately.
By subscribing you agree to receive Rule It In by email, about once a month. You will get a confirmation email first, and nothing is sent until you click it. Your address is stored by Kit (Kit.com, United States) and used only for this newsletter; Kit records which issues are opened and which links are clicked. Unsubscribe with one click in any issue. Privacy.