Syndesmosis is the scourge of Leinster
The scourge of syndesmosis has rolled through Leinster this season.
Last week, Leinster captain Isa Nacewa came back from it after six weeks out.
This week, Josh van der Flier is scheduled to return from it after six weeks out.
In simple terms, it ruined van der Flier's November and forced the 24-year-old to look on as Rhys Ruddock, Sean O'Brien, Jordi Murphy and Jack Conan all played international rugby.
Fellow flanker Dan Leavy was just about finding his feet in the PRO14 League when it took him out of the picture for - that's right - six weeks.
However, left wing Barry Daly, who had exploded into form with five tries from five matches this season to take him to the verge of international status, will not make it back from it in time for The Champions Cup.
The latter suffered the same injury as van Der Flier on the same night and, yet, Daly has not even returned to training.
So what is this mysterious 'syndesmosis' of the ankle?
It is best to begin with something everyone should know.
The two bones in the lower leg are the tibia and the fibula. The point just above the ankle where these two bones meet is a joint called the syndesmosis.
It differs from most other joints in that there is hardly any motion between the two bones.
Back in the day, it would have been described as a high-ankle sprain.
Nacewa first learned of syndesmosis when Rocky Elsom lost playing time to it.
"It is the flavour of the month and has been for a while," he said.
"It is very simple surgery, from what I've heard. It takes seven or eight minutes and you're back in no time.
"When it first came around, I think Rocky Elsom was one of the first to have it. It was maybe 16 weeks out.
"The staff we have got it down to nine weeks and down further from all the advances in medicine."