Elastic plate osteosynthesis, its biomechanics, indication and technique compared with rigid internal fixation

Classical stable plate osteosynthesis with its anatomical repositioning, absolute stability between fragments and medial support should only be applied to joint fractures and spongy bone. In cortical bone, the anatomical reposition connected with the plate promotes bone necrosis along the fracture and prevents callus formation. Direct cortical synthesis, a method also known as ''primary bone healing'', serves the bone's revascularisation and is not necessarily aimed at healing. Thus, this may also be termed ''necrosis healing'' Along the shaft of long bones, elastic plate osteosynthesis, a biological method, is safer than and superior to the rigid technique. This even applies to short oblique and transverse fractures insofar as nailing does not appear feasible. Elasticity is achieved by leaving a flexible stretch of at least 2-4 holes, i.e. as long as possible, without screws over the fracture and by employing a titanium plate. Thus, there is no punctate fatigue leading to plate breakage. The fitting of third fragments is deliberately left out. The same applies to all kinds of compression with lag screws, tension devices or DC-gliding holes - and this with the intention of allowing micromovements in the fracture's fissure. Periost and muscle are not removed and the fracture is not examined. Healing occurs spontaneously via a fixating callus forming within the first 3-6 weeks out of the periost-soft tissue combination. Histomorphological investigation dates the first woven-bone bridges between the fragments to 3 weeks subsequent to the accident. In Gottingen University trauma centre, 87 fractures have been attended to over 2 years using this technique. Despite considerable soft-tissue damage, no delayed bone healing, pseudoarthrosis or bone infection has been observed. The risks of elastic plate osteosynthesis lie in unbiological and exaggerated reposition methods, too short a flexible stretch, and insufficient anchorage of the screws.