Systematic evaluation of concomitant extensor tendon sheath injury in patients with distal intra-articular radial fractures in MDCT using the floating fat sign.

OBJECTIVES

We aimed to evaluate the involvement of extensor tendon sheaths in a large MDCT study group of patients with distal intra-articular radial fractures using the floating fat sign.

METHODS

603 MDCT scans of patients with acute intra-articular distal radial fractures (Frykman III-VIII) acquired between January 2005 and October 2011 were analysed in consensus by two radiologists. The extensor tendon sheath involvement was assessed for each extensor tendon compartment and visually graded from 0 to 2 based on the amount of fat-fluid levels.

RESULTS

Extensor tendon sheath involvement with fat-fluid levels was observed in 71.0% of the distal radial fractures, mainly in the second or third compartment. The frequency and degree of tendon sheath involvement was not related to the fracture severity. There was no statistically significant difference in the frequency of tendon effusion between the CT scans acquired before or after closed reduction.

CONCLUSION

Traumatic rupture of the extensor tendon sheaths with concomitant fatty effusion is a common finding in patients with distal intra-articular radial fractures.

KEY POINTS: • Fat effusions in tendon sheaths are frequent in distal intra-articular radial fractures. • Fat effusions in tendon sheaths are caused by traumatic bone marrow spilling. • Effusions typically involve the second and third compartment simultaneously.