Prospective Assessment of Clinical Tests Used to Evaluate Tibial Stress Fracture

Abstract

Background: Tibial stress fracture (SFx) is the most common SFx of the lower extremity. Presently, diagnostic accuracy of clinical examination techniques for tibial SFx remains suboptimal. Purpose: To assess the diagnostic effectiveness of 5 clinical tests for tibial SFx individually versus a test item cluster. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 50 patients with tibial pain (17 with bilateral symptoms) were assessed with 5 clinical examination tests (tibial fulcrum test, focal tenderness to palpation, heel percussion test, therapeutic ultrasound test, and 128-Hz tuning fork test) before they underwent diagnostic imaging (radionuclide bone scan). The application of the clinical tests was counterbalanced to minimize the likelihood of carryover effects. Patients provided a pain rating immediately before and after the application of each clinical test. Results: The prevalence of tibial SFx among the study participants was 52.2%. High levels of specificity were produced by the therapeutic ultrasound test (93.8%), tuning fork test (90.6%), and percussion test (90.6%). The fulcrum test had moderate to high specificity (84.4%). All tests demonstrated low levels of sensitivity, with the highest levels found for focal tenderness to palpation (48.6%) and fulcrum (45.7%). The fulcrum test provided the highest positive likelihood ratio (2.93), followed by the therapeutic ultrasound test (2.30). The fulcrum test had the lowest negative likelihood ratio (0.64), with the focal tenderness to palpation and tuning fork tests having negative likelihood ratios >1.0. Combinations of these clinical tests did not improve the prediction of tibial SFx above that observed among the individual tests. Conclusion: The clinical tests evaluated were generally highly specific, but all had low sensitivity. The fulcrum test provided the highest level of diagnostic accuracy; however, it was inadequate for definitive clinical management. Combining tests did not improve the diagnostic accuracy of tibial SFx.