Objectives

To determine the limits of spinal displacement before the onset of neurophysiological changes during spinal surgery. Assessing if the type of force applied or the section of the adjacent nerve roots increases the tolerance to displacement.

Purpose: To analyze the validity of the Ottawa Ankle Rules in our environment as a basis for ordering emergency radiographs after angle and/or mid-foot lesions.

Materials and methods: In this observational study we applied the Ottawa Ankle Rules and prospectively measured the result obtained in patients treated in our emergency department for ankle and/or mid-foot lesions from 1 July 2003 to 1 February 2004. The study excluded polytraumatized and multicontused patients as well as pregnant women and patients who had had the lesion for over 7 days. Radiographs were obtained for all the patients in the study regardless of the result produced by the Ottawa Rules.

Results: 687 patients were included in the study; 111 presented with a fracture. The Ottawa Rules showed a sensitivity of 97.2% (95% CI, mean: 96.0–98.4%). Negative predictive value was 98.5.% (95% CI, range: 96.4–98.7%). Specificity was 35 % (95% CI, range: 31.4–38.6%). Positive predictive value was 22.2% (95% CI, range: 19,1–25.3%).

Discussion and conclusions: The Ottawa Rules are valid in our environment as a decision-making aid when ordering radiographs of patients with angle and midfoot trauma. Applying these rules, savings of up to 30% can be made on radiographs ordered unnecessarily.