Sex differences in appropriate insertion depth for intraosseous access in adults: An exploratory radiologic...

Intraosseous access is a recommended alternative to venous access in emergencies. For its application, knowledge of the correct insertion depth is indispensable. We aimed to determine sex-specific differences on the appropriate insertion depth for intraosseous access in adults at the insertion sites most frequently used, namely the proximal and distal tibia and the proximal humerus.

In this exploratory retrospective study, we measured thickness of soft tissue cover, cortex and cancellous bone along the puncture line on magnetic resonance images or computed tomography scans. Inclusion criteria were both sexes, 18-90 years of age and appropriate image quality. Primary outcome was the appropriate insertion depth to reach the cancellous bone for each sex. This was defined as the corridor between (i) the sum of the soft tissue cover and the cortex and (ii) the sum of (i) plus the diameter of the cancellous bone. Secondary outcomes were the differences in thickness of each layer between sexes.

In 179 females and males, the appropriate insertion depth was 32.5-45.5 mm and 20.5-42.0 mm in the proximal tibia, 14.5-30.5 mm and 16.5-34.5 mm in the distal tibia, and 27.5-52.5 mm and 26.0-56.5 mm in the proximal humerus. Although females had a thicker soft tissue cover (+6.8 mm [95% CI 3.7-10.1], p < 0.01) in the proximal tibia, extrapolation by correlation analysis showed no clinically relevant difference between the sexes.

In adults, there are no sex-specific differences in the appropriate insertion depth for intraosseous access in the proximal or distal tibia or in the proximal humerus.