RESUMEN
<p><b>OBJECTIVE</b>To research many clinical data of nonunion cases and discover the reasons for low capacity of bone growth.</p><p><b>METHODS</b>From October 1999 to April 2009,the source material of 280 nonunion cases were conducted and followed up. The data of the study included 230 males and 50 females,with an average age of 39.4 years old ranging from 19 to 62 years. The fracture position was femur in 129 cases,tibia in 83 cases,humerus in 47 cases, feet radius bone in 21 cases, the ratio was 46:29.6:16.8:7.5. The survey included primary injury process,damage degree and the effect of first treatment,hospital level of first treatment,timing of surgery for the first time, the early callus growth conditions and whether there were obvious technical errors.</p><p><b>RESULTS</b>There were 129 femoral nonunion cases with complete data,121 cases derived from closed fractures, 8 cases from open fractures; 111 cases was aseptic nonunion. 90% of femoral aseptic nonunion had no obvious callus growth, 80% of first treatment performed intraday surgical internal fixation, 10% were undergone operation within three days and 90% was early surgery totally.</p><p><b>CONCLUSION</b>Low quality of bone callus growth is the main reason for current nonunion and the early surgical fixation has much to do with low quality of bone callus growth.</p>