ABSTRACT
Objective To evaluate correlation of radial head fracture with forearm interosseous membrane (IOM) injury.Methods Twenty-six patients with radial head fractures were studied prospectively between September 2007 and June 2010.There were 15 men and 11 women,with an average age of 37.6years (range,21-53).According to the Mason classification,there were 7 cases of type Ⅰ,9 cases of type Ⅱ,10 cases of type ⅢL All patients were subjected to forearm X-ray,CT scans and the MR within a week.Clinical and radiographic data of all the patients were collected.Spearman rank correlation statistical analysis was used to analyze the correlation between the radial head fracture and the IOM injury.Results The radial head fractures and IOM injury were directly related.The IOM injury was noted in all type of radial head fracture.The more severity radial head fracture had,the more IOM injury happened.In Mason Ⅰ-Ⅲ fractures,IOM injury was found in 2,4 and 7 cases respectively.The different degree of radial head fracture caused different effects on IOM injury.The severity of radial head fracture was correlated with damage degree of IOM.In Mason type Ⅰ and type Ⅱ fractures,the IOM injury were just partial disruption with distal part of the IOM and did not reach the biomechanically essential central band.In type Ⅲ fractures,central band disruption was found in 3 cases.Conclusion Mason Ⅰ-Ⅲ radial head fractures are associated with forearm IOM injury.There was a positive correlation between radial head fractures and IOM injury.If IOM lesions are suspected,magnetic resonance imaging should be performed,especially Mason Ⅲ fractures.
ABSTRACT
Objective To improve the accuracy of X-ray diagnosis of the deltoid ligament injury by evaluating the influence of plantar flexion on the diagnosis.Methods Twenty-four patients with ankle supination-extemal rotation fracture which was distal fibula fracture but no medial malleolus fracture were treated from February 2010 to December 2010.All the patients were taken Mortise radiograph with the ankle in four positions of plantar flexion(0°,15°,30° and 45°)applied with rotational stress and the deltoid ligament injury was identified with MRI.The medical clear space(MCS)and the superior clear space(SCS)on each radiograph were measured.The results were tested by a one-way analysis of variance model(ANOVA),based on the following criteria:(1)the MCS≥ 4 mm and MCS ＞ SCS,or when MCS≥5 mm and MCS ＞SCS.The MRI examination was taken as the gold standard to compare the influence of X-ray diagnosis of the deltoid ligament injury with different plantar flexions and different standards.Results The average MCS in four positions of plantar flexion(0°,15°,30°,and 45 °)with rotational stress were(4.10 ±0.79)mm,(4.55 ±0.72)mm,(4.99 ±0.56)mm and(5.71 ±0.86)ram,with statistical difference(P ＜0.05).The average SCS in four positions of plantar flexion(0°,15°,30°,and 45°)were(3.56 ±0.41)mm,(3.50 ±0.43)mm,(3.71 +0.44)mm and(3.93 ±0.51)mm,with no statistical difference in the four groups(P ＞0.05).With the MSC≥4 mm and MSC ＞ SCS as the diagnostic criteria,the prevalence of false-positive findings of deltoid injury based on the ratio with the four positions of plantar flexion(0°,15°,30° and 45°)were 50.0％,66.7％,88.9％ and 94.4％ respectively.With the MSC≥5 mm and MSC ＞SCS as the diagnostic criteria,the prevalence of false-positive findings of deltoid injury based on the ratio with the four positions of plantar flexion(0°,15°,30° and 45°)were 5.6％,11.1％,38.9％ and 77.8％ respectively.Condusions Different plantar flexion angle is an important factor for X-ray diagnosis of deltoid ligament injury of the ankle joint.The prevalence of false-positive findings of deltoid injury increases with the increase of plantar flexion.