Background: Injuries of the extensor tendons can take place as complications of treatment in forearm fractures stabilized with flexible intramedullary nails (FIN). We do not know of any previous reports of flexor pollicis longus (FPL) entrapment in a distal radius fracture treated with FIN.
Patient and Methods: A 14-year-old boy sustained a displaced fracture of distal radius and a greenstick fracture of distal ulna. Fracture of the radius was percutaneously fixed with a flexible intramedullary nail. Extension deficit of the IP joint of the thumb was recorded after nailing. Extensor pollicis longus (EPL) was explored and found intact at the time of nail removal, four months after surgery. The patient was referred to the Children's Hospital, where entrapment of the flexor pollicis longus (FPL) at the fracture site was suspected, imaged with MRI and released surgically 13 months after the initial injury.
Results: Thumb IP joint extension improved intra-operatively after the muscle release and returned to normal within a year.
Conclusions: FPL entrapment at the fracture site should be remembered as a possible complication of the fracture itself, or as a complication of the percutaneous FIN of distal radius fractures.
