OBJECTIVETo explore the causes and mechanisms of children elbow joint injury led to elbow varus.

METHODSOne hundred children with elbow varus causded by elbow joint injuries were retrospectively studied during January 2005 to April 2008 in department of child orthopedics involving 54 males and 46 females with an average age of 9.7 years old ranging from 7 to 16 years. The anterior-posterior and lateral position X-ray films of elbow joint continuous 12 to 18 months (means 15 months) of all the cases were collected. The postoperative X-ray films were observed to analyze the cause of elbow varus.

RESULTSThere were 81 cases caused by epiphyseal dysplasia, growth imbalance, included 47 cases of humeral supracondylar fractures, 16 cases of entire epiphysis separation of distal humerus, 11 cases of humeral lateral condyle fractures, 7 cases of humeral medial condyle fractures. There were 19 cases caused by ulna drift and rotation of the distal fracture end,the ulnaris cortibal bone crushing and collapse involving 11 of humeral supracondylar fractures, 2 of entire epiphysis separation of distal humerus, 5 of humeral lateral condyle fractures, 1 of humeral medial condyle fractures.

CONCLUSIONThere are two main factors of formation for the children elbow varus deformity: the main causes is epiphysial dysplasia after fracture and imbalance growth of epiphysis; the secondary reasons is ulnar inclination of the distal fracture, rotation of the distal fracture, fracture shift such as ulnar bone cortical extrusion collapse.