Evaluation of Clinical Applicability of Stress Radiography for Shoulder Instability: Correlation between the Degree of Displacement and the Physical Examinations / 대한정형외과학회잡지

ABSTRACT

PURPOSE: The purpose of this study is to examine the clinical applicability of stress radiography in patients presenting with shoulder instability. MATERIALS AND METHODS: Fifty-six patients diagnosed with shoulder instability and 20 healthy volunteers participated in the study. Degree of displacement of the humeral head as measured on stress radiography using a Telos GA-IIE device was compared with the results of the physical examinations. Four types of stress radiography were captured while applying 15 daN of force anteriorly (AER0 and AER60) and posteriorly (PER0 and PER60) at two different positions (1) 90° of abduction combined with 0° of external rotation, and (2) 90° of abduction combined with 60° of external rotation. RESULTS: The degree of displacement of affected shoulders of 44 patients showed significantly larger displacement than normal shoulders (p<0.05), and the comparison between 56 affected shoulders of the patients and 40 normal shoulders of the volunteers showed significantly larger displacement only in PER0 and PER60 of the patients (p<0.05). Among the four radiographs of affected shoulders, AER60 showed significantly less displacement (p=0.046). The anterior drawer test under anesthesia of 16 patients who underwent surgery for anterior instability showed positive correlation with AER0 (Spearman's rho=0.56, p<0.024). Significantly larger anterior displacement of the load and shift test was observed in the subgroup with anterior displacement more than 3 mm (p=0.028), and higher positive frequency of the Kim's test was observed in the subgroup with posterior displacement more than 3 mm (p=0.005). CONCLUSION: Stress radiography using a Telos GA-IIE device could discriminate the affected shoulder. Although it could not replace individual physical examinations, the degree of displacement correlates with some physical examinations for shoulder instability.