Mid- to Long-Term Outcomes of Two-Stage Revision Arthroplasty for Periprosthetic Joint Infection of the Shoulder

<b>Background/Objectives</b>: Periprosthetic joint infection (PJI) after shoulder arthroplasty is often treated with a two-stage approach, but the data on the mid- to long-term outcomes remain scarce. This study aimed to evaluate the clinical outcomes of two-stage revision arthroplasty for shoulder PJI with a minimum follow-up of five years. <b>Methods</b>: This retrospective study identified 59 shoulders in 58 patients who underwent the first stage of a two-stage revision arthroplasty for shoulder PJI at our institution between 2007 and 2018. Of these, 29 shoulders in 29 patients (49.2%) did not undergo reimplantation or the patient passed away before reaching five years of follow-up. The remaining 30 shoulders in 29 patients were included in the study. The clinical assessments included the active range of motion, the visual analogue scale (VAS) for pain, the Subjective Shoulder Value (SSV), the Constant Score (CS), and the 12-Item Short Form Survey (SF-12), supplemented by detailed clinical and radiological evaluations. <b>Results</b>: The mean age of the 29 patients was 75.9 ± 10.4 years. The average follow-up duration was 8.3 ± 2.8 years. The most common indications for primary shoulder arthroplasty were primary osteoarthritis (n = 12, 40%) and fractures (n = 12, 40%). At the first stage, nine cases (30%) showed negative cultures, while <i>C. acnes</i> and <i>S. epidermidis</i> were each identified in eight cases (26.7%). Four shoulders (13.3%) experienced recurrent infections. At the follow-up, the mean abduction was 86 ± 48.1°, the mean forward flexion was 97.8 ± 50.1°, the mean external rotation was 20.5 ± 19.9°, and the internal rotation reached the lumbosacral region. The mean VAS pain score was 1.5 ± 2.1, the mean SSV was 51.8 ± 28.4%, the mean CS was 54.6 ± 21.0, and the mean SF-12 was 81.0 ± 16.0. <b>Conclusions</b>: Two-stage revision arthroplasty for shoulder PJI results in satisfactory subjective and objective outcomes, with a low overall reinfection rate. However, the high rates of mortality and failure to reimplant must be carefully considered when managing expectations in this challenging cohort.