A hose that is twisted or has kinks can pose a safety hazard due to the pressure that may build up. The liquid going through a hydraulic hose needs to flow freely. When kinks prevent this from happening, you run the risk of the hose bursting. In fact, kinks, twists, abrasions and crushing are responsible for many cases of blown hoses.
Kinks and twists in hydraulic hoses also increase the risk of oil leaks. It's best to go ahead and replace your hose if you notice kinks and twists.