New Classification Of The Monteggia Fracture And Its Clinical Meanings

Objective:To explore the clinical meaning of the new classification of theMonteggia fracture.Methods: In a prospective study,,125patients with acute Monteggiafractures from Jan2007to Dec2012were discussed according to theclassification mentioned above. During this follow-up,9patients were lostto follow up,116patients were successfully followed for9to31months(mean,18.9months). The rate of follow-up was92.8%. In this116patients,49were left elbow injuries,and67were right elbow injuries.Twenty patients were associated with the radial nerve injury.Their agesranged from1to14years (mean,4.7years). Time since injury ranged from1hour to26hours (mean:4.2hours).(1) Inclusion criteria:①Patientssuffered from Monteggia fractures according to the new classification，agedless than18years;②Time since injury<3weeks;③Fresh fracture， not treated by otherhospital．(2) Exclusion criteria:①openfracture;②complicated by acutecompartment syndrome which need emergency intervention;③any diseasehistory threatening life,such as malignant tumors;④severe mental diseaseor disability to live himself in daily life;⑤poor in compliance or deny toparticipate in the trial program;⑥participated in other trialprogram in1month before the follow-up;⑦any conditions that researcher consideredwould influence the effectiveness or safety of the trial. All fractures wereclassified according to the new classification system.Then the patients wererandomized into two groups based on their ID number of outpatient orinpatient. Those with odd ID number were allocated to group A,and thosewith even ID number were distributed into group B. Patients in group Awere in the treatment of closed reduction. Operation would be performed i fclosed reduction failed. Patients in group B were treated by operation. Sixty-six fractures were classified as type Ⅰ.Group ⅠA had37patients whoreceived closed manipulation. Group ⅠB were composed of31patients whoreceived surgical operation. Fifty-five cases were classified as type Ⅱ,26cases in group Ⅱ A,and44cases in group Ⅱ B. The reduction failed in15cases from the group Ⅱ A. Only four cases were classified as typeⅢ. Twocases originally arranged in group Ⅲ A failed in the closed treatment,so allthe4cases of type Ⅲ were in group Ⅲ B. The clinical outcomes wereanalyzed during the6months after the initial treatment.(3)TreatmentMethods:①ClosedＲ eduction Group: The deformity of the ulnar or radiuswas first corrected,then the dislocation of the radial head was reduced. Thepatient was placed in supine position,after the brachial plexus block orgeneral anesthesia,the shoulder was abducted with the extended elbow an dthe supination of the forearm. Two assistants held the distal upper arm andthe wrist joint,respectively. The surgeon held the ends of the fracture site，and pressed the ulnar fracture ends in the opposite direction of the angulardeformation by lifting and pressing methods,which could make the angularand overlap deformity corrected.Then the surgeon pressed the radial head inthe opposite direction of dislocation and reduced the radial head.Thereduction was considered as successful if the radial head did not dislocateagain while the elbow was slightly flexed. For patients with both ulnar andradius fractures,the ulnar and radius overlap and angular deformity shouldbe first corrected,and then the dislocation of the radial head was restored.The reduction could be performed twice more following the failure of thefirst reduction.②Operation group: This group were treated by openreduction and internal fixation. Boyd incision was made along theposterior-lateral side of the elbow joint with a length of10cm. Theskin,subcutaneous tissue and fascia were cut，then the ulnar and radius werevisible. The fractures were anatomically reduced and fixed with plates.Then the radial head was reduced with the elbow flexed to90degrees. A1.4mm Kirschner wire was inserted into the posterior elbow side along theradius canal to fix the humero-radial joint. The cast was immobilized at theelbow in the flexion of90degrees. The Kirschner wire was removed6weeks postoperatively and functional exercise began. The plates wereremoved3months postoperatively.③Management of the radial nerve injury: 12patients were combined with radial nerve injury,but were not treated bythe nerve exploration． Only drugs were used to restore the nervefunction． The symptoms started to recover during the8to12weeks afterthe restoration of the radial head. Results One hundred and sixteen patientswere followed up. The mean period of the follow-up was18.9months(range,9-31months). Nine cases were lost to follow up. The rate of thefollowup was92.8%. Sixty one cases from typeⅠ,51cases from type Ⅱand4cases from type Ⅲ weresuccessfully followed up. The functional outcomewas evaluated using the HSS scoring. The outcome would be regarded asbad if closed reduction failed in group A. There were no significantdifferences both between group Ⅰ A and Ⅰ B (P=0.822>0.05),and betweengroup Ⅲ A and Ⅲ B (P=0.40>0.05).The difference between group ⅡA andⅡ B was statistically significant (P=0.00＜0.05). Discussion Thoughmultiple classification systems for Monteggia fracture exist in clinicalapplication,the Bado classification is most commonly used,which dividesthe Monteggia fracture into4types according to the direction of radial headdislocation in the imaging examination.For its neglect of the separation ofthe upper radio-ulnar joint,the Bado classification can not guide the primeclinical choice. Through the long-term clinical observation,we found thatthe operation would be needed because the closed reduction frequentlyfailed in those patients with the so-called complete dislocation of thehumero-radial joint,which was shown by X-ray that the distance betweenthe radial side of the coronoid process and the medial side of the radial headwas larger or equal to the width of the radial head in antero-posteriorposition of the elbow,or the inferior border of the radial head totally wereseparated with the superior border of the ulnar in lateralposition.Comparatively,the mild separation of the upper radio-ulnar jointmay be generally treated by the closed reduction. Severe separation of theupper radio-unlar joint is mostly caused by high energy trauma,which couldmake the annular ligament totally ruptured and lose its constraint of theradial head.The ruptured annular ligament and the adjacent soft tissuewould be entrapped into the joint space,which could impede the restorationof the radial head. Even the closed reduction was successfullyperformed,the unstable ends of the ulnar fracture site might be easily displaced after the fixation of the splint or cast. However,the patients withthe mild separation of the upper radio-ulnar joint usually suffered therelatively lower energy trauma. In addition，the radial head epiphysis of thechildren were more fragile compared with their ligaments.Therefore,thoseradial heads were dislocated from the inferior border of the annularligament,and the rupture of the annular ligament did not occur in most o fthose patients. After the correction of the green stick fracture deformity ordisplacement,their radial head could always be restored to its position,andgood clinical outcomes would be obtained due to their low possibility ofre-displacement or re-dislocation． Conclusions The new classificationmethod can facilitate the treatment for the Monteggia fracture. Closedreduction should be the prime choice for the type Ⅰ fracture,and operationwould be recommended for the type Ⅱ and Ⅲ fractures. It could obtainsatisfactory clinical outcomes to choose the appropriate treatment accordingto the new classification system,Meanwhile,unnecessary iatrogenic injurycould be avoided.Considering that the sample size of our study islimited,more observation and investigation need to be further performed.