Techniques

Many techniques are used to achieve internal fixation:

• screws - used to compress plates against bone or bone fragments against each other. In the latter, the thread should not engage both fragments as this will tend to hold them apart rather than bring them into apposition.
  
  
• plates - used to hold the bones correctly in position and to compress the two ends together. Usually applied on the tensile side of the fracture. Complications arise from their size - difficulty with access and with skin closure - and from their rigidity - may produce disuse osteoporosis or stress fractures at the plate ends.
  
  
• intramedullary nails - indicated particularly for mid - shaft fractures in long bones and for maintaining length and alignment. Problems may arise from rotation - poorly controlled - and in reaming a channel which will hold the rod firmly along the entirety of the medullary cavity.
  
  
• locking nails - a variation on intramedullary nails in which transverse screws fix the bone fragments to the nail. The screws provide for better control of rotation and are indicated in segmental fractures of the long bones. However, they are often difficult to insert.
  
  
• wires - tension band wiring is useful for transverse fractures of the patella and olecranon where the fracture may be displaced by muscle action. Wire is applied as a loop to the outer side of the fracture so that it comes under tension as the joint flexes. The main problems are slippage and breakage of the wire. Cerclage wiring is often used in spiral fractures but occasionally may cause tips of the fragments to break off or more rarely, the entire bone to break transversely.
  
  
• nail-plates -a nail and plate may be used for example, to fix a trochanteric fracture of the femur.