Role of preoperative magnetic resonance imaging in patients with quiescent septic arthritis undergoing primary total hip arthroplasty.

Aim: to evaluate the role of preoperative magnetic resonance imaging (MRI) in assessing patients with a history of undergoing total hip arthroplasty.

Materials And Methods: retrospective consecutive study of patients with previous history of septic arthritis who underwent MRI scans of their hips prior to primary hip arthroplasty surgery and who also had minimum 2 years follow up postoperatively. Detailed radiographic examinations were obtained, demographic and microbiological data collected. The primary outcome measure was whether a preoperative MRI scan had influenced the surgical decision-making and planning. Rate of recurrence of infection and complications was also collected at final follow up.

Results: sixteen patients with were included. There were 4 males and 12 females with average age at time of primary hip arthroplasty 51.7 years (range 22-75). Five patients had childhood septic arthritis with no documented microbiology data. Eleven patients had adult onset septic arthritis. In patients with childhood septic arthritis the MRI findings were similar to those with degenerative joint disease and had no added value to the routine surgical work up. MRIs of patients with adult onset septic arthritis showed persistent findings of effusion, marrow oedema and soft tissue oedema and had no added value to the surgical planning. All but one underwent single stage total hip arthroplasty. At final follow up, with average 4.6 years (range 2-8), none had a recurrence of infection.

Conclusion: In our experience, preoperative MRI scans did not influence the surgical decision making and are not recommended for routine practice in the surgical work up of prior to total hip arthroplasty.