Multiple loose bodies are seen in -a) Osteochondritis dessicansb) Synovial chondromatosisc) Osteoarthritisd) Rheumatoid arthritis e) Osteogenesis imperfecta
Causes of loose bodies include :-


Osteoarthritis 
Osteochondritis dessicans
Osteochondral fracture (injury)           
Charcot's disease
Synovial chondromatosis


Among these, osteochondral fracture causes single loose bodies, while all other can cause multiple loose bodies, maximum by synovial chondromatosis (up to hundred’s).
abc
bc
acd
bcd