RESUMEN
<p><b>OBJECTIVE</b>To investigate the clinical effect of the treatment of the ununited lower limb fracture with reamed intramedullary interlocking nail.</p><p><b>METHODS</b>Fifty-two patients with ununited lower limb fracture were treated with intramedullary interlocking nail (femur 36, tibia 16). The main cause of nonunion was interternal fixation loosening or fracture (41 cases, 78.8%), other reasons included bone defection, bone infection or too much traction of fracture (11 cases, 21.2%). According to X-ray classification: 41 cases in type hypertrophy, 11 cases in type atrophy. All these patients need operation to remove the primary implant, clean the hard bone, ischemia bone and scar, manual ream and fix by intramedullary interlocking nail, then bone graft were done around the fracture site. With the knee joint stiffness, relax it by manipulate or operation.</p><p><b>RESULTS</b>Beside 3 superficial infection (2 delayed healing and 1 healing after debridement), other 49 wounds healed on time. All cases were followed up for an average of 25.2 months, ranging from 12 months to 39 months. All the ununion healed from 5 to 11 months, mean union time were 6.1 months. Deep tissue infection, fat embolism, implant loosening, nail broken or nonunion were not found in this series. According to judet standard on the movement of knee, the excellent-good rate was 82.7%.</p><p><b>CONCLUSIONS</b>Intramedullary interlocking nail is effective to treat nonunion of lower limb fracture.</p>