There are only few manuscripts on the role of static 18F-fluoride PET for detection of lesions in patients referred for non-oncologic indications The purpose of the study is to prospectively assess the added value of Fluoride PET/CT in the clinical setting of acute knee injury. The findings of Fluoride PET/CT will be correlated with those found on arthroscopy and MRI which the currently used diagnostic techniques with a high, however, not perfect diagnostic accuracy regarding the issue of bone injury which is a critical component on the long term outcome after knee injury.