Osteomyelitis on MR imaging as a key predictor of recurrent septic arthritis of the shoulder.

• Osteomyelitis on preoperative MR imaging was the best predictor associated with recurrent septic arthritis of the shoulder on multivariable analysis including clinical, laboratory, and MR findings. • In multivariable analyses focused on each bone marrow abnormality, with adjustment for clinical and laboratory parameters, the presence of reactive bone marrow edema and osteochondral erosion on MR imaging showed no significant association with recurrent septic arthritis of the shoulder.