Like spud42 said: You can put the drive into a IDE2USB-Case and it shold work without problems.
If your HDD really has corrupted sectors (which are not adressed in the filesystem), a low-level-format might help. I'm not even sure, if the PS2s FS even 'mark' defective sectors at all...
But a low-level-format will make those sectors un-accessible to the FS, since they are marked as corrupted internally/in the HDDs DB.
So yes,... Even if a HDD seems to be totally corrupted,... In a few cases, you can get them back running (maybe with lesser space), if you low-level-format it.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux