Background Radial neck fractures account for 5%-10% in elbow joint fractures and most of them are slightly displaced or non-displaced types.Satisfactory therapeutic results can be achieved by conservative treatment.As to severe displaced radial neck fractures,it is controversial in selection of therapeutic methods and curative effect clinically.To explore clinical therapeutic effect of radial neck fractures with elastic intramedullary nail and accumulate experience for diagnosis and treatment,23 cases of radial neck fracture were treated with elastic intramedullary nail from May 2006 to September 2009 in our hospital.Methods From May 2006 to September 2009,23 cases of radial neck fracture were admitted into our hospital and treated with elastic intramedullary nail,including 17 male and 6 female,aged from 6 to 13,and the average age was 9.3 years.Traumatic mechanisms were classified as fallen injuries with 21 cases and wringer injuries with 2 cases.Twenty cases were in right elbow and 3 cases were in left elbow.Operation time from injury ranged from 1 to 5 days,and averaged in 2.3 days.There were 3 cases of associated injuries on other parts of the elbow joint,including 2 cases of medial collateral ligament injury and 1 case of fracture of medial epicondyle of humerus.All patients were given X-ray and CT examinations after hospitalization.According to the severity of radial neck angular displacement and Judet classification system,3 patients were classified into type II,16 patients into type Ⅲ,and 4 patients into type IV.Close reduction and elastic intramedullary nail fixation:After successful anesthesia,the patient was in spine position with the affected limb abducted.The nail would be inserted from distal to proximal.The insertion site was just 1 to 2 cm proximal to the distal radial epiphyseal plate level. A small incision was made.The underlying tendons and superficial branch of radial nerve were well protected.An awl was used perpendicular to the lateral radius to open the cortex.And then proceeded the awl 45°to radial shaft into bone canal.An AO elastic intramedullary nail was pre-bended on its tip and inserted into radius retrorward.The optimal diameter of the nail was 1/2-2/3 of the minimum transverse diameter of the radial shaft.Proximally rotated,the nail body is pushed to the radial head with traction of the forearm,and the space of humeroradial joint is broadened by varus of the elbow.The displaced radial head was pressed from outside by doctor’s finger to correct angular deformity. Then the elastic intramedullary nail was further introduced into the radial head to achieve further angular correction. The nail was then rotated by its T handle to correct lateral displacement of the radial head.After successful reduction under Carm fluoroscopy,gently hammer at the nail tail for further stability of fracture end.Cut off the nail tail with 0.5 cm left out of cortical bone in the distal radius,which will make it convenient for extraction.After the operation,the elbow joint is fixed with plaster in 90°flexion of neutral position.Percutaneous poking reduction by Kirschner wire and elastic intramedullary nail fixation:For patient with large tilted angle of radial head,the lateral borders of the radial neck have impacted or compression fracture of various levels and the periarticular joint capsule is lacerated or interrupted,resulting in difficulties of closed reduction for radial head,hence,percutaneous reduction of fracture end with Kirschner wire assisted is essential.With the traction of forearm by one assistant and the countertraction of upper limb by the other,the space of humeroradial joint is enlarged by the varus of elbow maintained in semiflexion.The selection of entry point depends on the situation of fracture displacement in the lower outer bottom of the elbow.Kirschner wire in the right hand,the operator put it into the fracture end under the C arm fluoroscopy.Through the use of distal fracture end as fulcrum and lateral bone cortex of radial head as pressure point,the reduction is gained by elevating the nail tail,poking the radial head with the tip of Kirschner wire,and in the meanwhile pushing it in the reverse direction of fracture shift via the left thumb.After that,the intramedullary nail is inserted to further assist the reduction and fixation of fracture end.Open reduction and elastic stable intramedullary nail fixation:For patient with large fracture displacement and inefficiency of closed or Kirschner wire assisted reduction,it is feasible to perform open reduction in order to prevent soft tissue damage caused by further closed reduction.Intraoperative attention should be paid to prevent damage to the deep branch of radial nerve,then expose and reduce the radial head under the fluoroscopy of C arm,and insert the elastic intramedullary nail to maintain the reduction of fracture ends.Treatment of combined injury:There are 3 patients with injuries on other parts of the elbow joint in this group,including 2 cases of medial collateral ligament injury and 1 case of humeral medial epicondyle fracture.No special treatment was given to the 2 patients with medial collateral ligament injury.Open reduction and internal fixation via medial incision of elbow joint as well as treatment of radial neck fracture were conducted at the same time in treatment of humeral medial epicondyle fracture.Postoperative management:All patients were given regular anti-inflammation therapy within 3 days after operation.The affected limb was externally fixed with plaster in 90°flexion of the elbow joint for 3 or 4 weeks.After removal of the plaster,the patients were instructed to take functional exercises of forearm pronation and supination as well as elbow flexion and extension.Follow- ups were conducted in the 6^th week,12^th week 6^th month,1^st year,2^nd year,and the 3^rd year,including taking X-ray films,understanding the state of fracture healing and change of radial head,and as well understanding the state of functional recovery of elbow joint and whether complications did exist.Results Evaluative criteria of curative effect:In accordance with Métaizeau postoperative X-ray assessment standards:Anatomic reduction is excellent;tilted angle <20°is good;tilted angle ranging from 20°to 40°is medium;tilted angle >40°is poor.In accordance with Métaizeau functional evaluative standards in the later stage:No limitation of elbow and forearm activity is excellent;The sum of the limited elbow flexion and extension activity,or the limited forearm pronation and supination activity < 20°is good;The sum of the limited elbow flexion and extension activity,or the limited forearm pronation and supination activity ranging from 20°to 40°is good,and >40°is poor.2 All patients of this group include 2 cases of open reduction,6 cases of percutaneous poking assisted reduction by Kirschner wire,and the remaining 15 cases of simple closed reduction and elastic intramedullary nail fixation.The operative time ranged from 20 to 50 minutes,and the mean time is 36.4 minutes.Intraoperative bleeding was from 5 to 20 ml with the average of 8.3 ml.The duration of external fixation with plaster was 3 to 12 months and the average period was 3.7 months.Fracture healing time after operation ranged from 3 to 4 months,and the mean time was 3.7 months.The time of removing internal fixator was 3 to 12 months with an average of 4.7 months.Postoperative follow-ups last 6 to 38 months and the average is 17.5 months.Postoperative X-ray assessment:18 cases were excellent,3 cases were good,1 case was normal,and the assessment was good and excellent in 91%.Functional assessment was conducted by on the basis of Métaizeau functional evaluative standards:16 cases were excellent,6 cases were good,1 case was normal,and the assessment was good and excellent in 96%.Among the patients were 2 cases of enlargement deformation of the radial head epiphysis and 1 case of periarticular abnormal calcification.No case of infection,nonunion and delayed union was detected.Conclusions Elastic intramedullary nailing for radial neck fracture is a treatment method with minimal invasiveness,less bleeding,less interference with fracture healing,low complication rate,and the act of both reduction and fixation.It is simply operated in treatment of radial neck fracture with satisfactory effects,and worth of promoting in clinical practice.