Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Propionibacterium acnes (P. acnes) is a gram-positive anaerobic bacillus commonly isolated from the flora of the face, chest, and axilla region. It has emerged as a major pathogen responsible for postoperative shoulder infections after both arthroscopy and arthroplasty procedures. Patients with P. acnes shoulder infection typically present with normal laboratory values (white blood cells (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)) making diagnosis difficult. Several intraoperative tissue cultures should be obtained and cultured in both agar plate and broth in aerobic and anaerobic conditions for a minimum of 13 days to optimize the sensitivity and specificity to detect P. acnes. The utilization of intraoperative frozen sections to detect P. acnes infection is not reliable. Risk factors include male, cloudy synovial fluid, lucencies around the implant, and periprosthetic membrane formation. Managements include irrigation and debridement, single or two-staged revision, and intravenous antibiotics. Open biopsy prior to the final implantation (two-staged revision) may help detect persistent P. acnes infection. Penicillin and cephalosporins are effective against clinical P. acnes infection and biofilm in vitro. Combination antibiotic therapy with rifampin and daptomycin may further increase the clinical efficacy of treatment.

Snapping scapula syndrome at the superomedial corner of the scapula can lead to significant shoulder dysfunction. Bursectomy with or without partial scapulectomy is currently the most beneficial primary method of treatment in patients in whom nonoperative therapy fails. Arthroscopic access to the scapulothoracic space is simple and reproducible with the technique described in this report. The bursal tissue can be cleared, optimizing visualization of the scapulothoracic space and the anatomic structures. Arthroscopic decompression of the scapulothoracic bursa and resection of the superomedial corner of the scapula are highlighted in a video example.