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What is Non union occurs in the following fractures EXCEPT and explain in detail?
i.e. (Trochanteric): (95-CDT-orthopedics 4th) (38- J maheshwari 3rd)Intertrochanteric 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 pole**)a. 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" fragment)4. Infectiona. Bone death (sequestrum)b. Osteolysis (gap)c. Loosening of implants (motion)5. General age; nutrition; steroids, anticoagulants, radiation, bums, predispose to nonunion6. Distraction from traction or internal fixationCommonest site of Malunion -(i) Colle's (ii) Supracondylar (iii) Intertrochantric