Concern for<unk>  space involvement with soft tissue<unk> :
Proximity of soft tissue<unk>  to<unk> 
Visible<unk>  capsule surface
Periarticular fracture
In these situations<unk>  involvement is obvious and orthopedic surgery/washout is necessary without further testing:
Foreign body in<unk>  on X-ray
Intra-articular air on X-ray or CT
Obvious<unk>  involvement of fracture with an open fracture on X-ray
Proximity of soft tissue<unk>  to<unk> 
Visible<unk>  capsule surface
Periarticular fracture
Foreign body in<unk>  on X-ray
Intra-articular air on X-ray or CT
Obvious<unk>  involvement of fracture with an open fracture on X-ray
Open joint injury
Compartment syndrome
Open fracture
Contusion
Acute knee injury
Crush syndrome
Knee fractures
Degloving injury