This is a case report which follows a patient who received multiple false positive synovial alpha-defensin test results following a revision for total knee arthroplasty. The report looks at the importance of generalizability in diagnostic testing and how a lack thereof can extend the cost and duration of care.

Our 10-year multicenter study examines the epidemiology, presentation, management, and outcomes of elbow native joint septic arthritis, a rare condition with risks like reoperation and mortality. Common symptoms included pain and swelling. Synovial fluid white blood cell counts were often low, with monosodium urate crystals also noted. Staphylococcus aureus was the main pathogen, and 72.2 % of patients underwent open debridement.

This retrospective case-matched study evaluated males and females with staphylococcal PJI (periprosthetic joint infection) treated with two-stage exchange arthroplasty. We matched 156 males and females for age, type of staphylococcal infection, and joint involved. We compared clinical parameters related to presentation, treatment, and outcome. We did not find a statistically significant difference in outcome between males and females treated with the same surgical approach at our institution.

We present the first published case of bilateral extensor tenosynovitis caused by Coxiella burnetii. C. burnetii should be considered in patients with inflammatory osteoarticular disease, including tenosynovitis, when conventional cultures are negative especially in elderly, male, or immunocompromised patients with exposure to animals.

This paper describes five cases of prosthetic joint infection (PJI) caused by Mycobacterium avium complex (MAC). Infections occurred in both immune competent and immunosuppressed patients. Interestingly, using the Musculoskeletal Infection Society diagnostic criteria for PJI may miss some cases of MAC PJI. Treatment courses and outcomes are described.