Quantitative three-dimensional computed tomography measurement of radial head fractures.

BACKGROUND

We developed a method to quantitatively analyze fracture fragment morphology on quantitative 3-dimensional computed tomography (3DCT) images in terms of size, shape, and articular surface area.

MATERIALS AND

METHODS

We analyzed 46 adult patients with a computed tomography scan of a fractured radial head with quantitative 3DCT. We defined an unstable fracture as complete loss of cortical contact of at least 1 fragment. Of the patients, 3 had a Mason type 1 fracture (all stable), 26 had a type 2 fractures (7 stable [27%] and 19 unstable [73%]), and 17 had a type 3 fracture (all unstable). The volume and articular surface area of each articular fracture fragment were measured. A small fragment was defined as having a volume of less than 100 mm(3) or an articular surface of less than 100 mm(2).

RESULTS

Partial head fractures (Mason type 2) (26 fractures) are usually multi-fragmented (19 of 26 [73%]) and often have small fragments by volume (32 fragments) and surface area (46 fragments) criteria, particularly when the fracture is displaced and unstable. Only 4 of the 17 patients (25%) with whole-head fractures (Mason type 3) had greater than 3 fragments, but 9 of 17 fractures (69%) with 3 or fewer fragments had small fragments.

CONCLUSIONS

According to this initial application of quantitative 3DCT analysis, partial-head fractures are often complex and difficult to repair (small fragments), and most whole-head fractures have 3 or fewer fragments, but many of those fragments are small and may be difficult to repair.