A PROSPECTIVE CONTROLLED-STUDY OF DIAGNOSTIC-IMAGING FOR ACUTE SHIN SPLINTS

Objective: The purpose of this prospective, observational study was to examine the relationship of clinical examination, plain radiograph (X R), triple-phase bone scan (TPBS), and magnetic resonance imaging (MRI ) in the investigation of patients presenting with acute shin splints. Methods: 23 subjects with exercise induced lower leg pain and diffuse tibial tenderness of less than 3 months' duration were recruited. Sub jects were excluded if there was clinical evidence of compartment synd rome, muscle hernia, or stress fracture. Each subject underwent XR, TP BS, and MRI within 2 wk of physical examination. Four asymptomatic con trols under;vent TPBS and MRI. Clinical findings. XR, TPBS, and MRI fi ndings were independently recorded using a consistent template and sub sequently analyzed. A single consensus lesion was chosen that provided the greatest overlap and highest grade to allow comparison of clinica l and imaging findings. Sensitivity and specificity were calculated fr om data relating to clinical findings and diagnostic imaging. Results: Eighteen subjects had bilateral symptoms and five unilateral with a m ean duration of symptom of 5.4 wk (+/-3.5). Of 41 symptomatic lower le gs, there were TPBS abnormalities in 36 and MRI findings in 34. Analys is of clinical findings to TPBS and MRI demonstrated a sensitivity and specificity of 84%, 33% and 79%, 3346, respectively. Assuming TPBS as the ''gold-standard,'' MRI findings demonstrated a sensitivity of 95% and specificity of 67%. There was poor agreement between the grading of TPBS and MRI (k = 0.3). In the 5/46 asymptomatic limbs. 3/5 demonst rated uptake on bone scan and 4/5 signal change with MRI. Imaging abno rmalities were similarly seen in the four control patients. Conclusion s: MRI may be used rather than TPBS and radiographs for evaluating acu te tibial pain in athletes where avoidance of radiation exposure is de sirable. Similar sensitivity and specificity may be expected from both investigations; however, in the light of abnormal TPBS and MRI findin gs in control and asymptomatic limbs, we recommend further studies be performed to define the extent of nonpathological TPBS and MRI changes .