A very unique weapon
The tonfa sword is a very unique adaptation of the Tonfa itself. Its used quite often in the various Manga and Anime characters found in comic books and in many video games and even more in the film industry. More so than an actual real life fighting weapon.
There are a few variations of the Tonfa sword as seen here:
A very unlikely weapon to be seen in the dojo.!!
However, the Tonfa sword is not a generally available martial arts weapon, unlike most other martial arts weapons that are readily available from high quality onlinemartial arts suppliers.
With all that said the Tonfa Sword can really only be categorised as a fantasy martial arts weapon that is more suitable for video and comic book use.