Purpose <p>Hemiarthroplasty with concentric glenoid reaming (ream-and-run [RnR] arthroplasty) may be considered in patients with glenohumeral arthritis who want to avoid activity restrictions of prosthetic glenoid components. However, there are concerns of glenoid wear and medialization following RnR. While the factors responsible for glenoid medialization are unclear, the presence of bacteria may lead to weakening and osteolysis of the glenoid bone. This study sought to correlate the presence and amount of <i>Cutibacterium</i> cultured from RnR arthroplasties that were revised with the amount of radiographic glenoid medialization.</p> Materials and methods <p>Patients who underwent open revision surgery after primary RnR with a minimum of six months between primary and open revision surgery were included. Semi-quantitative <i>Cutibacterium</i> load from cultures at the time of revision was calculated. Glenoid medialization was measured from radiographs taken post-primary RnR and before revision surgery. Glenoid medialization amount and rate were assessed against <i>Cutibacterium</i> presence and load.</p> Results <p>Radiographs of 39 shoulders with average follow-up of 2.6 ± 2.4 years were analyzed. Twenty-five (64.1%) were culture-positive (≥ 2 positive deep cultures with <i>Cutibacterium</i>). Patients in the culture-positive and negative cohorts had similar glenoid wear rates of 1.4 and 1.3&#xa0;mm per year, respectively (<i>p</i> = 0.892). There was no significant association between the amount of glenoid medialization and the presence or load of <i>Cutibacterium.</i></p> Conclusions <p>We found no association between glenoid medialization after RnR arthroplasty and the presence or load of Cutibacterium at subsequent revision surgery. Longer follow-up studies are needed to better assess <i>Cutibacterium’s</i> role in glenoid medialization after RnR arthroplasty.</p> Level of evidence <p>Level IV; Case Series.</p>