When a GP prescribed bilateral orthotics for a patient with flat feet, the cure turned out to be worse than the disease, with one of the devices leading to a plantar vein thrombosis, according to a rare case report.

The 61-year-old patient presented to the orthopaedic foot clinic at hospital in Leidschendam, the Netherlands, complaining of acute and severe pain in the medial plantar region of the right foot.

The pain had started abruptly five days earlier without any preceding trauma, doctors report in BMJ Case Reports.

Initially, the pain was only present on weight-bearing, but by the time the man presented to the clinic, the pain was continuous, and he was unable to walk without crutches.