Misdiagnosis of the acute phase of undifferentiated arthritis as pyogenic arthritis: A case report and literature review.

Undifferentiated arthritis is a disease that clinically presents with symptoms and signs of inflammatory arthritis but does not meet the specific diagnostic criteria of rheumatoid arthritis (RA) or spondyloarthropathy. Here, we report our experience with a patient whose diagnosis of RA was delayed due to a lack of evidence for RA. The patient complained of knee joint swelling and pain, but the clinical features did not match those of typical pyogenic arthritis. Because infection could not be completely ruled out, the patient was treated for pyogenic arthritis using arthroscopic synovectomy and antibiotics. However, the pain was not relieved and the rheumatologist suggested a diagnosis of undifferentiated monoarthritis, which is an early stage of RA. The pain eventually spread to other joints, leading to the diagnosis of RA, approximately two months after the initial visit. Considering undifferentiated arthritis and making appropriate differential diagnoses is important to avoid unnecessary treatments such as surgery or prolonged antibiotic use. Clinical relevance: Awareness of the possibility of undifferentiated monoarthritis, an early stage of RA, may be helpful in treating patients with recurrent knee effusion.

Comparison of tibial plateau fracture surgical outcomes between young and elderly patients: are outcomes really poorer in the elderly?

INTRODUCTION: Several studies have reported that total knee arthroplasty (TKA) is a suitable solution to treat elderly patients with complex tibial plateau fractures. The purpose of the present study was to compare surgical treatment outcomes after open reduction internal fixation (ORIF) between elderly and younger patients. MATERIALS AND METHODS: We reviewed patients with plateau fracture (OTA/AO classification types 41B and 41C) who underwent ORIF at two academic trauma centers between November 2006 and October 2019. Of the 341 patients, 76 were ultimately included in the younger group (< 60 years old) and 77 in the elderly group (≥ 60 years). The average follow-up was 24 months (range 12-96 months). The primary outcome was any common complication of plateau fracture, namely post-traumatic arthritis and alignment change. Conversion to TKA, Reduction loss, coronal malalignment, non-union, union time, infection, and limb length discrepancy (LLD) were also assessed. RESULTS: The elderly group had a significantly higher prevalence of diabetes, but there were no other significant differences between the groups in terms of patient demographics, fracture characteristics, and operation characteristics. We detected no differences between the groups in terms of post-traumatic arthritis (p = 0.216), alignment change (p = 0.093), conversion to TKA (p = 0.681), reduction loss (p = 0.079), coronal malalignment (p = 0.484), non-union rate (p = 0.719), infection (p = 0.063), LLD (p = 0.154), or time to union (p = 0.513). Logistic regression analysis revealed that age > 60 years was not associated with treatment failure, defined as either post-traumatic arthritis greater than grade II or non-union (p = 0.468). OTA/AO classification type 41C2 (p = 0.019), type 41C3 (p = 0.008), and malreduction (p = 0.050) were significant risk factors for failure. CONCLUSION: Age ≥ 60 years is not an independent risk factor of poor radiographic outcome and high complication rate in tibial plateau fractures. This indicates that ORIF is still a good solution to treat elderly patients, similar to their younger counterparts.