Prospective Randomised Sternal Closure Study Sternalock 360 Plates vs Conventional Stainless Steel Wires

Introduction/Background Information Since the inception of cardiac surgery in the early 1960s, division of the sternum has provided the superior access to cardiac structures. Cardiac surgery may involve treatment of the coronary arteries, valves or major vessels such as the ascending aorta. In children, correction of congenital malformations is also performed.

The conventional bone fixation during the 1960s was the placement of stainless steel wires around or through the sternum, predominantly as single wires which were tensioned by twisting. In the 1980s, it became fashionable for some cardiac surgeons to pass the wire twice around the bone (as would be the case repairing a fence on a farm), so-called "figure of 8" configuration and tensioning again occurring by twisting the wires. There have been no adequate studies investigating which of these two techniques may be superior.

In simple terms, bone healing is promoted by

• Minimising movement of the bone edges at the fracture site and
• Improved alignment of the bone edges

The sternum is a connecting bone that moves in multiple planes to transfer load and position the limbs in space during every day functional tasks and respond to the demands of respiration. The healing of the sternum is in the context of many efforts by the treating physicians and physiotherapists to encourage activities that might cause distracting forces at the sternal fracture site. Additionally, simple everyday activities by the patient such as coughing, deep breathing, sneezing, transferring in and out of bed, turning over in bed and driving all lead to substantial distracting forces acting on the sternal fracture site1. External fixation is not encouraged because the patient needs to have significant chest wall movement in order to breathe and clear sputum as part of the recovery from surgery.