The effects of screw orientation in severely osteoporotic bone: A comparison with locked plating

The effect of screw insertion angle and thread type on the pullout strength of bone screws in normal and osteoporotic cancellous bone models

“…There has been a previous study of the pullout resistance of individual screws inserted at varying angles to the axis of pullout in PU foam [29] but it was restricted to foams of a single density (0.32 g cm −3 ). In addition, a recent study has investigated the effects of screw orientation and load to failure of a plate-bone construct that was attached to 0.09 g cm −3 PU foam (used to model severely OP bone); these authors noted that further study is required in bone of varying density to determine where the benefit of angled screws, to increase fixation strength, is lost [37]. No previous study has reported any general relationship between bone screw insertion angle and screw pullout strength with reference to OP bone.…”

“…Only a small number of studies have investigated angled screws [29][30][31][32][33][34][35][36][37] and most are specific to a single anatomical site [30][31][32][33][34][35]. There has been a previous study of the pullout resistance of individual screws inserted at varying angles to the axis of pullout in PU foam [29] but it was restricted to foams of a single density (0.32 g cm −3 ).…”

Evidence for Success with Locking Plates for Fragility Fractures

“…Locked plates tolerated higher loads than conventional plates with various patterns of angled screws. Furthermore, the advantage of angles screws appears to be lost in osteoporotic bone [54].…”

“…Five papers summarizing in vitro mechanical testing of comparisons of the stability and load tolerance of locked plates compared with traditional plates were identified [27,35,49,53,54]. Osteoporotic cadaveric bones as well as synthetic bone models designed to mimic osteoporotic bone were used.…”

“…Osteoporotic cadaveric bones as well as synthetic bone models designed to mimic osteoporotic bone were used. Four of the models used gaps to simulated comminution [27,35,53,54], and all studies tested the constructs in cantilever bending, and axial and torsional loading. One study compared locked plating with application of the plate to the lateral distal fibula to a conventional plating using the posterolateral antiglide positioning of the conventional plate [35].…”