Value of the longitudinal distribution symmetry assessment of the edema zone in the differential diagnosis of myositis ossiifcans

WENG Lei; LI Kai; KONG Ling-yi; CHENG Xiao-guang; LI Xiao; LU Zhan-xing

doi:10.3969/j.issn.2095-252X.2014.09.017

Abstract：Objective To investigate the value of the longitudinal distribution symmetry assessment of the edema zone in the differential diagnosis of myositis ossiifcans ( MO ).Methods From March 2008 to June 2012, 15 patients with early or medium-term MO and 17 patients with bone or soft tissue tumors and infectious diseases conifrmed by surgical pathology or biopsy were adopted, whose clinical data were retrospectively analyzed. All the patients were divided into two groups, including the MO group (n=15 ) and the non-myositis ossificans ( NMO ) group (n=17 ). The superior and posterior fringes of the edema zone were identiifed, and the ratio of their distances from the center of the ossiifed focus was measured. All the data were analyzed statistically. A nonparametic method was employed to generate a receiver operating characteristic ( ROC ) curve.Results The ratios of the superior and posterior fringes of the edema zone were 0.62±0.24 in the MO group and 0.99±0.06 in the NMO group. All the data were analyzed between the two groups by independent samplest-test, and the differences were statistically signiifcant (P<0.001 ). With 0.855 as the critical point, the sensitivity was 86.7% and the speciifcity was 100% in the diagnosis of early and medium-term MO.Conclusions The ratio of the superior and posterior fringes of the edema zone from the center of the ossiifed focus is not equal to 1 in the patients with early and medium-term MO. The longitudinal distribution symmetry assessment of the edema zone may supply some referential information for the differential diagnosis of early and medium-term MO, which is helpful to improve the accuracy of qualitative diagnosis.