Propionibacterium acnes Infection of the Shoulder After a Manipulation Under Anesthesia for Stiffness Status Post Open Reduction and Internal Fixation Proximal Humerus: A Case Report

INTRODUCTION: Propionibacterium acnes infection has been more frequently recognized as an important cause of post-operative shoulder infection. Infection by this organism is more frequently seen after total shoulder arthroplasty but can also be seen after an open reduction and internal fixation (ORIF) of the proximal humerus. We present a patient with P. acnes infection of the shoulder that only became apparent after he underwent a manipulation under anesthesia for stiffness of the shoulder after an ORIF. CASE REPORT: Our patient was a 64-year-old male who sustained a proximal humerus fracture after a motorcycle collision and underwent an ORIF of the proximal humerus with plate fixation. Postoperatively, the patient had stiffness of the shoulder so he underwent a manipulation under anesthesia of the shoulder. On post-operative day 5, the patient developed an erythematous area over the incision. This area opened up and began to drain by post-operative day 10. The patient underwent an irrigation and debridement of the shoulder with partial removal of hardware. He was also started on antibiotics and clinically cleared his infection. CONCLUSION: Infection by P. acnes can be difficult to diagnose and may present with shoulder stiffness as the only initial symptom. This case is unique as there have not been any documented cases of a latent P. acnes infection presenting after a manipulation under anesthesia of the shoulder. There must be a high clinical suspicion for P. acnes infection in any patient presenting with post-operative stiffness.