Protection from stress in bone and its effects. Experiments with stainless steel and plastic plates in dogs

Abstract

Modulus of tensile strength Fatigue limit elasticity =UTS as percentage (MN/rn2) (MN/m') of UTS 3 16 stainless steel .

Effect of Instability on Experimental Fracture Healing

“…A rigid immobilization protects bone from normal loading, and numerous reports have been given that show cancellous transformation and weakening of existing cortical bone after plate osteosynthesis (Tonino et al 1976, Woo et al 1976and Paavolainen et al 1978. It is probable that the same principle applies to new bone in the 34' process of osteogenesis, stress protection giving a slow rate of healing.…”

“…That instability gives increased production of external callus is considered an established fact. The mechanical properties of callus are, however, a matter of disagreement, as an increasing number of authors seem to find that "a certain amount" of external callus promotes earlier functional bridging of the fracture gap (Uhthoff & Dubuc 1971, Tonino et al 1976and Sudmann 1976. Kiintscher (1950) states from clinical experience that "good stability" gives "better" healing.…”

Retrospective Study of Implant Failure in Orthopaedic Surgery

“…Adequate post-operative immobilization was ensured in all cases. plastic failure occur due to minor loads in small plates and secondary major trauma in large plates [5]. The most common failure of plate is fatigue failure.…”

Stress protection by external fixation of the rabbit tibia

“…Stress protection of various types of osteosynthesis in diaphyseal bones has been described (Tonino et al 1976, LAftman et al 1980). Terjesen and Benum (1983b, c) showed that the degree was dependent on the type and the duration of fixation.…”