Correlation Between New Classification Of Monteggia Fracture And MR Images Of Forearm Interosseous Membrane Injury

Objective1 Analyze the fresh Monteggia fracture DR and MRI image data,characterize patterns of forearm interosseous membrane after forearm trauma,in order to understand the proximal radio-ulnar joint separation degree and interosseous membrane injury extent.2 To investigate the correlation between proximal radio-ulnar joint separation degree and interosseous membrane injury extent.Evaluate a new classification for fresh Monteggia fracture of children,aim at optimizing Monteggia fracture treatment strategy.Subjects and Methods1 Subjects: In a prospective study,collect the patient clinical data from October 2013 to August 2015 in our hospital.There were 38 cases Monteggia fracture in children accordance with the inclusion criteria,24 male and 14 female patients,aged 5-11 years old,the average age is 6.9 years old.On left side 13 cases,25 cases on the right side,with ipsilateral distal radial epiphysis fracture in 1 case,with radial nerve injury in 6 cases,ulnar nerve injury in 1 case.According to Bado classification,17 cases of BadoⅠ,1 cases of BadoⅡ,18 cases of BadoⅢ,2 cases of Bado IV.According to the X-ray and the new classification standard,typeⅠ12 cases,typeⅡ 24 cases,typeⅢ 2 cases.All patients were closed and fresh injury,within 1 week to hospital for treatment,time is after injury 1hours-7 day,the average time is 32.6 hours.2 Methods: New typeⅠand New typeⅡ were imaged on The 1.5T superconducting MR scanner(Magnetom Essenza),before MRI examination communicate with their families and sign the informed consent MRI safety inspection.Use the elbow joint surface smooth coil,each upper extremity was braced in elbow extension and forearm supination.Three imaging sequences T1 WI,T2WI,STIR were used to obtain the axial、sagittal and coronal images,a slice thickness of axial scanning is 3-5mm with 1mm skip.The scan range is from the elbow to the wrist.The image quality of MRI in tendon,muscle and fascia outline clear,no artifact is better.Measure proximal radioulnar joint separation distance on standard elbow radiographs X-ray.Compare with normal children’s forearm interosseous membrane MRI images,observe the interosseous membrane of MRI patients,characterize patterns of IOM injury,record the number of different pathological changes of the axial images(the distance of pathological changes).To study the relationship between the interosseous membrane injury and proximal radio-ulnar joint separation degree,analyze the relationship between the new clinical classification for fresh Monteggia fracture of children and IOM lesion.According to the new classification system,typeⅠwas in the treatment with closed reduction,typeⅡand typeⅢ were conducted with operation.Using American hospital for surgery(HSS)score evaluate the forearm function after treatment.Results1 4 patients was failed to obtain the MRI images,including 1 case of type I,3 cases of type II.At last obtain 11 cases of type I,21 cases of type II MRI image.Interosseous membrane display from about 30mm-45 mm distance of cricoid cartilage surface in axial image.Axial TWI1,TWI2 images can display the complete interosseous membrane of forearm,coronal and sagittal images can not distinguish the interosseous membrane.2 The extent of the damage: 11 type I cases of Monteggia fracture in children with forearm interosseous membrane demonstrate pathological changes,7 cases with interosseous membrane disruption,4 cases of the interosseous membrane without disruption.21 cases of type II Monteggia fracture were associated with the pathological changes of the interosseous membrane,18 cases with disruption,3 cases without disruption.Type I with mild proximal radio-ulnar joint separation,the main of pathological interosseous membrane is the short injury and disruption distance;the severe proximal radioulnar joint separation,the short injury and disruption distance of interosseous membrane.Interosseous membrane damage degeree associated with the distance of proximal radio-ulnar joint stretched.It plays an important role in proximal radio-ulnar joint stability,preventing the radius and ulna lateral separation.Analysis by Pearson ′ s correlation,proximal radio-ulnar joint separation distance and interosseous membrane pathological changes was positively correlated.(r=0.799,P=0.000),P < 0.05,3 34 patients received postoperative 6-18 months(mean 9.5 months)follow-up(follow-up rate is 89.47%),All the fractures healed well and good on the line,no malunion,delayed healing,nail tract infection and osteomyelitis,good in appearance and joint function.the functional outcome was evaluated using the HSS scoring,typeⅠwas excellent in 8,good in 2,fair in 1,typeⅡwas excellent in 13,good in 7,fair in 1,typeⅢ was good in 1,fair in 1,the excellent and good rate is 91.18%.ConclusionsMRI is a very effective non-invasive method for the diagnosis of injury of forearm IOM.Forearm interosseous membrane injury is relative to the proximal radio-ulnar joint separation degree,the more proximal radio-ulnar joint separation degree,the heavier the forearm interosseous membrane injury.The new classification system can facilitate the treatment of Monteggia fracture,it is a kind of practical theory worth extending.