Painless Sharp Wound Debridement With Lidocaine-23%-Tetra-caine-7% Gel Versus EMLA 5% Cream

Inclusion Criteria: * Participants between 18 years and 90 years * Chronic leg ulcer(s) (duration \> 4 weeks) with biofilm or necrotic layers which require consecutive sharp debridement for at least two times (of the same ulcer) * Minimal ulcer area of 1 cm2 * Leg ulcer has to enter into one of the following well defined aetiologies: venous, mixed venous-arterial, arterial, hypertensive ischemic leg ulcer (Martorell), vasculitic, ecthyma (covering \>90% of all observed leg ulcers) * Informed consent as documented by signature and being able to follow the study protocol (cognition) * Proficiency in German, oral and written information Exclusion Criteria: * Women who are pregnant or breastfeeding (Women of childbearing potential need to perform a pregnancy test (urine test) within 24 hours prior to the study intervention and need at least one simple acceptable contraceptive method) * Participants with hypersensitivity or allergy to lidocaine, prilocaine, tetracaine or auxiliary supplies contained in either EMLA® 5% cream or lidocaine-23%-tetracaine-7% gel. * Participants with peripheral neuropathy (over 4/10 insensitive points with Semmes monofilament) are excluded due to disturbed pain perception, which could potentially influence the results. * Participants that were previously included in this clinical trial * Participants with a total wound area larger than 200 cm2