OBJECTIVE: The objective of this paper is to measure the volume occupied by the most widely used internal fixation devices for treating femoral neck fractures, using the first 30, 40 and 50 mm of insertion of each screw as an approximation. The study aimed to observe which of these implants caused least bone aggression. METHODS: Five types of cannulated screws and four types of dy namic hip screws (DHS) available on the Brazilian market were evaluated in terms of volume differences through water displace ment. RESULTS: Fixation with two cannulated screws presented significantly less volume than shown by DHS, for insertions of 30, 40 and 50 mm (p=0.01, 0.012 and 0.013, respectively), fixa tion with three screws did not show any statistically significant difference (p= 0.123, 0.08 and 0.381, respectively) and fixa tion with four cannulated screws presented larger volumes than shown by DHS (p=0.072, 0.161 and 0.033). CONCLUSIONS: Fixa tion of the femoral neck with two cannulated screws occupied less volume than DHS, with a statistically significant difference. The majority of screw combinations did not reach statistical significance, although fixation with four cannulated screws pre sented larger volumes on average than those occupied by DHS.
Femoral Neck Fractures; Fractures Fixation; In ternal; Hip
