[Three-dimensional printing combined with distal humeral osteotomy for cubital varus deformity in children].

Objective: To explore clinical effect of three-dimensional(3D) printing combined with distal humerus osteotomy for children with cubital varus deformity.
Methods: From January 2017 to January 2020, 17 cubital varus deformity children treated with distal humerus osteotomy were retrospective analysis, included 11 boys and 6 girls, aged from 5 to 11 years old with an average of (7.8±1.7) years old. A model of affected side elbow joint was made by 3D printing technique before operation, pre-operation was performed on the model. Three-dimensional model was successfully used for distal humeral osteotomy during operation. Carrying angle, flexion and extension angle of elbow joint were compared before and six months after operation, and Flynn scoring criteria was used to evaluate clinical effect.
Results: All children were followed up for 6 to 12 months with an avergae of (9.6±1.7) months. One child occurred wound infection and healed completely after dressing change. No complications such as nonunion, internal fixation and nerve injury occurred. Carrying angle of affected limb was improved from (-20.8±2.4)°before operation to (7.2±2.3)°at 6 months after operation ( P <0.01). Angle of affected elbow joint extension improved from (-5.6±3.9)° before opeation to(-2.6±2.1)°at 6 months after operation ( P <0.01). There was no significant difference in extension angle of elbow joint between preopertaion and postopertaion at 6 months ( P >0.05). While there was no difference in elbow joint function on the healthy side and affected side at 6 months after opertaion ( P >0.05). According to Flynn scoring criteria, 13 patients got excllent results and 4 moderate.
Conclusion: Three-dimensional printing combined with distal humerus osteotomy in treating elbow varus deformity could receive satisfactory clinical effect, which could accurately assist correction of cubital varus deformity, restore physiological structure and function of elbow joint.