<prompt> Non union occurs in the following fractures EXCEPTNeck of femurScaphoidTalusTrochanteric  <response>: i.e. Trochanteric: 95-CDT-orthopedics 4th 38- J maheshwari 3rdIntertrochanteric fracture always unite. Malunion gives rise to Coxa vara decreased femoral neck shaft angle, shortening and the leg in external rotationNON UNION - a fracture that fails to show progressive evidence of a healing over a 4 to 6 month periodExamples of Non unionCauses of Non union1. Neck of the femur1. Excessive motion : inadequate immobilization2. Scaphoid Commonest site2. Diastasis of fracture fragmentsProximal polea. Soft tissue interposition3. Lateral condyle of the humerusb. Distraction from traction or internal fixationc. Malposition4. Lower third of the ulnad. Loss of bone5. Body of the talus3. Compromised blood supplya. Damage to nutrient vessels6. Distal tibial diaphysisb. Stripping or injury to periosteum and muscle7. Proximal diaphysis of the fifth metatarsalc. Free fragments; severe comminutiond. Avescularity because of internal fixation devices8. Segmental fracture of long bones large butterfly fragment4. Infectiona. Bone death sequestrumb. Osteolysis gapc. Loosening of implants motion5. General age; nutrition; steroids, anticoagulants, radiation, bums, predispose to nonunion6. Distraction from traction or internal fixationCommonest site of Malunion -i Colles ii Supracondylar iii Intertrochantric 