Humeral periosteal spur sign with osteolysis as an early radiographic indicator of low-grade Cutibacterium acnes prosthetic shoulder infection.

Abstract

The early diagnosis of low-grade Cutibacterium acnes prosthetic shoulder joint infection is challenging due to the lack of clinical and laboratory signs. Patients present with atypical symptoms such as stiffness or failure to improve shoulder function. The diagnosis is often delayed with impact on long-term outcomes. We present the case of an 82-year-old man with a surgical site erythema occurring 7 weeks after reverse shoulder arthroplasty associated with a light raise of C reactive protein (20 mg/L). At 9 weeks, radiographs revealed a 'periosteal spur sign' (humeral calcar) and localised adjacent osteolysis. Open surgery showed morphological signs of infection confirmed by growth of C acnes in eight cultures. A 'periosteal spur sign' is a useful early radiographic indicator of low-grade prosthetic joint infection usually occurring with some delay after clinical symptoms. A high clinical index of suspicion is needed to proceed with biopsies and to initiate combined operative and antibacterial treatment.

• Authors: Stefan Bauer, Benjamin Dietz, Andrej Trampuz, Oscar Marchetti
• Journal: BMJ case reports (BMJ Case Rep) Vol. 14 Issue 3 (Mar 25 2021) ISSN: 1757-790X [Electronic] England
• PMID: 33766962 (Publication Type: Case Reports, Journal Article)
• Copyright: © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.

Topics

• Aged, 80 and over
• Humans
• Humerus
• Male
• Osteolysis
• Propionibacterium acnes
• Shoulder (diagnostic imaging, surgery)
• Shoulder Joint (diagnostic imaging, surgery)
• Shoulder Prosthesis