To X-Ray or Not to X-Ray?

Ordering musculoskeletal imaging is a decision that every medical professional makes on a regular basis. It can be a confusing decision on when to order, or even which imaging modality offers the best results. Fortunately, there are numerous published musculoskeletal clinical decision rules, on topics ranging from cervical spine1-3 to the foot and ankle4-7, that will help us make those decisions.

Refined Quebec Decision Rules

For instance, Emond, et al.8 refined the Quebec decision rules for imaging of shoulder dislocations. In their study they found three discrete combinations of factors which identified all 40 clinically significant fracture dislocations:

  1. Aged 40 years or older AND humeral ecchymosis,
  2. Aged 40 years or older AND first episode of dislocation, or
  3. Younger than 40 years AND injury mechanism other than a fall from standing height or an atraumatic injury.

They reported a sensitivity of 1.0 with a specificity of 0.34, showing that the refined clinical decision rules are an excellent screening tool for the clinician and decision making for imaging.


Appropriate Referrals

This is one example of how clinical criteria help the practitioner with their decision to order imaging. These screening tools help keep the cost of healthcare down, decrease the amount of unnecessary imaging, and decrease harm to the patient by excess radiation exposure or being subject to unnecessary interventions. By following these recommendations, patients can be appropriately referred, or not, for imaging.

  1. Mower WR, Hoffman J. Comparison of the Canadian C-Spine rule and NEXUS decision instrument in evaluating blunt trauma patients for cervical spine injury. Ann Emerg Med. Apr 2004;43(4):515-517.
  2. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. Dec 25 2003;349(26):2510-2518.
  3. Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. Jama. Oct 17 2001;286(15):1841-1848.
  4. Stiell I. Ottawa ankle rules. Can Fam Physician. Mar 1996;42:478-480.
  5. Stiell I, Wells G, Laupacis A, et al. Multicentre trial to introduce the Ottawa ankle rules for use of radiography in acute ankle injuries. Multicentre Ankle Rule Study Group. Bmj. Sep 2 1995;311(7005):594-597.
  6. Stiell IG, Greenberg GH, McKnight RD, et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. Jama. Mar 3 1993;269(9):1127-1132.
  7. Stiell IG, Greenberg GH, McKnight RD, Wells GA. Ottawa ankle rules for radiography of acute injuries. N Z Med J. Mar 22 1995;108(996):111.
  8. Émond M, Le Sage N, Lavoie A, Moore L. Refinement of the Quebec decision rule for radiography in shoulder dislocation. CJEM 2009;11(1):36-43.