'90s Star Parker Lewis -- My Shattered Leg Needed More Surgery

Turns out '90s star "Parker Lewis" can lose ... at surgery ... the actor tells TMZ he had to go under the knife a SECOND time following his near-death boating accident, because the first surgery didn't cut it.

Corin Nemec -- star of "Parker Lewis Can't Lose" -- was in a horrific accident back in January, which left him with a shattered leg. Nemec had one surgery (below) earlier this year and was on the road to recovery ... but the break was so extreme, it didn't heal properly.

Nemec tells TMZ ... to fix the problem, doctors had to open his leg up again in order to have his femur reamed -- an intense process which involved inserting a titanium rod into his leg, followed by major grafting work. Pretty painful stuff.

Nemec says he's trying to stay positive despite the setback -- and hopes this surgery will finally fix the problem so he can move on with his life.