Comparison between dedicated MRI and symphyseal fluoroscopic guided contrast agent injection in the diagnosis of cleft sign in athletic groin pain and association with pelvic ring instability

ObjectiveTo compare dedicated MRI with targeted fluoroscopic guided symphyseal contrast agent injection regarding the assessment of symphyseal cleft signs in men with athletic groin pain and assessment of radiographic pelvic ring instability.MethodsSixty-six athletic men were prospectively included after an initial clinical examination by an experienced surgeon using a standardized procedure. Diagnostic fluoroscopic symphyseal injection of a contrast agent was performed. Additionally, standing single-leg stance radiography and dedicated 3-Tesla MRI protocol were employed. The presence of cleft injuries (superior, secondary, combined, atypical) and osteitis pubis was recorded.ResultsSymphyseal bone marrow edema (BME) was present in 50 patients, bilaterally in 41 patients and in 28 with an asymmetrical distribution. Comparison of MRI and symphysography was as followed: no clefts: 14 cases (MRI) vs. 24 cases (symphysography), isolated superior cleft sign: 13 vs. 10, isolated secondary cleft sign: 15 vs. 21 cases and combined injuries: 18 vs. 11 cases. In 7 cases a combined cleft sign was observed in MRI but only an isolated secondary cleft sign was visible in symphysography. Anterior pelvic ring instability was observed in 25 patients and was linked to a cleft sign in 23 cases (7 superior cleft sign, 8 secondary cleft signs, 6 combined clefts, 2 atypical cleft injuries). Additional BME could be diagnosed in 18 of those 23.ConclusionDedicated 3-Tesla MRI outmatches symphysography for purely diagnostic purposes of cleft injuries. Microtearing at the prepubic aponeurotic complex and the presence of BME is a prerequisite for the development of anterior pelvic ring instability.

Automated summary

This study aimed to compare dedicated MRI with targeted fluoroscopic guided symphyseal contrast agent injection for the assessment of symphyseal cleft signs and radiographic pelvic ring instability in athletic men with groin pain. The results showed that MRI was more accurate in diagnosing symphyseal cleft injuries and played an important role in the development of anterior pelvic ring instability.