Aim: It was investigated if AO 3.5-mm titanium cortical screws used in comb
ination with LC-DCP plates for osteosynthesis are likely to break during su
rgery. Method: The moments of torque that lead to breakage of the screw wer
e determined experimentally in a hardwood model. The insertion angle was va
riable: 90 degrees in centric (n = 30) and excentric (n = 30) positioning,
70 degrees (n = 30) and 50 degrees (n = 30). Minimal moments that led to sc
rew breakage were compared to insertion moments that were measured intraope
ratively in 7 fracture operations (radial, ulnar, tibial, fibular; 32 screw
s). Results: Minimal moments that led to screw breakage were 2.6 Nm (90 deg
rees centric), 2.8 Nm (90 degrees eccentric), 2.7 Nm (70 degrees) and 2.4 N
m (50 degrees). The maximal intraoperatively measured insertion moment was
2.25 Nm (radius). Conclusions: In this investigation, minimal moments that
led to screw breakage in an experimental setting were higher than maximal i
nsertion moments that were recorded during surgery. It is concluded that sc
rew breakage related to the given implant combination is unlikely if correc
t surgical technique is performed.