Choosing Wisely to Diagnose Osteomyelitis in Patients with Chronic Leg Ulcers: a Retrospective Chart Review

From the 2019 HVPAA National Conference

Dr. Archana Khandelwal (Griffin Hospital), Dr. Olugbenga Arole (Griffin Hospital, Derby, CT)

Background

Plain radiographs (X-ray) and or magnetic resonance imagines (MRI) are routinely used to establish the diagnosis of osteomyelitis. This study sought to assess whether MRIs were over-utilized by clinicians to investigate osteomyelitis in patients with chronic leg ulcers.

Methods

This study was conducted in a community hospital in Connecticut. Through chart reviews, we retrospectively reviewed the electronic health records of patients admitted from October 2015 through October 2017 with chronic lower leg ulcers due to different etiologies. We reviewed the results of the X-rays and follow-up MRIs which were done on the same admission to rule out any evidence of infection of the bone.

Results

Of the 241 charts reviewed, 56 patients with leg ulcers were investigated for osteomyelitis using both X-rays and MRIs. Thirty seven (66.1%) patients’ X-ray results were negative for osteomyelitis, while 10 (17.9%) patients’ results were equivocal and 9 (16.1%) patients’ results were positive. Among the 37 patients with negative X-ray results, MRIs showed osteomyelitis in 8 (21.62%) patients, equivocal results in 8 (21.62%) patients, and no evidence of osteomyelitis in in 21 patients (56.75%). Among 10 patients who showed equivocal findings on X-ray, MRI confirmed the presence of osteomyelitis in 3 patients, 1 patient was still equivocal and 6 patients’ results were negative for osteomyelitis. Among the 9 patients whose X-rays showed evidence of osteomyelitis, MRI reconfirmed this diagnosis in 8 patients, while 1 patient was still equivocal on MRI. There was no significant difference (p=0.7923) in the proportion of patients whose initial X-rays diagnosed osteomyelitis compared with their additional MRI results.

Among the patients who X-rays were positive for osteomyelitis at the initial assessment, there was no significant difference (p=0.7923) in the proportion of patients whose results were positive for osteomyelitis when only an X-ray would have been done as compared with when MRIs were done in addition to their initial X-rays (see Table 1 and 2). Despite these similar results, the cost for doing only X-ray among patients whose X-rays were positive for osteomyelitis at their initial assessment would have been $994.50 as compared with $8,938.44 when MRIs would have been done in addition to their initial positive X-rays.

Conclusions

Despite the higher sensitivity of MRI imaging in evaluating the presence of osteomyelitis when compared to X-rays, there are occasions where X-rays are adequate to make the diagnosis.

Clinical Implications: Our study highlights the importance of doing imagining investigations for osteomyelitis using sequence of testing with X-rays and the MRIs. Our data suggests X-rays seem to be sufficient in diagnosing osteomyelitis when the results are positive in the initial investigation. MRIs are useful to substantiate the diagnosis of osteomyelitis in situation where the results of the X-rays were negative or equivocal. A larger multisite trial is warranted to elucidate these finding.