Inclusion Criteria:  Informed consent as documented by signature ≥ 18 years old Understanding of the German language (written and oral) Single and multiple finger injuries Primary flexor tendon injuries in Zone I-V for the fingers and/ or thumb Treated by the hand surgery department at the Inselspital Bern Treated with at least a 4-strand core suture  Exclusion Criteria:  < 18 years old Inability to follow the procedures of the study, e.g. due to language problems, diagnosed psychological disorders or dementia of the patients Replantation of the injured finger Fracture of the injured finger Primary tendon reconstructions