Hip hemiarthroplasty for femoral neck fractures in end-stage renal disease patients on dialysis compared to patients with late-stage chronic kidney disease.

INTRODUCTION: Hip fractures in patients with end-stage renal disease (ESRD) are associated with frequent complications and poorer outcomes. Patients on chronic dialysis are at additional risk of dialysis-related complications such as myocardial infarction and early osteolysis. We analysed the complications and implant survivorship of hemiarthroplasty in patients with femoral neck fractures with late-stage chronic kidney disease with and without pre-existing dialysis. METHODS: We conducted a retrospective case-control study of 28 patients with ESRD and 31 patients with chronic kidney disease (CKD) Stages 3-5, who had a total of 62 fractures treated with hemiarthroplasty between 2005 and 2015. The mean age of the patients was 68.33 (50.21-86.45) years. The mean follow-up time of the group was 39 months. Patient demographics, complications, outcomes and follow-up radiographs were analysed for differences. RESULTS: Patient in both groups had statistically similar demographics and comorbidity scores except for a higher incidence of hyperparathyroidism in ESRD patients on chronic dialysis (nine patients vs. zero patients; p = 0.001). These patients were more likely to develop cardiopulmonary complications in the perioperative period (odds ratio [OR] 5.04; p = 0.04) and implant loosening on radiographic analysis (OR 8.75; p = 0.02). The incidence of loosening was higher in patients with hyperparathyroidism (OR 9.80; p = 0.002). Cemented techniques, however, did not appear to be significantly associated with intraoperative fractures or loosening. CONCLUSION: Patients with ESRD on chronic dialysis were more likely to develop cardiopulmonary complications and implant loosening after hemiarthroplasty for femoral neck fractures. Hyperparathyroidism should be optimised, as it may prevent loosening. Our study did not show any difference in complications or outcomes for cemented fixation.

Accuracy of the α-defensin lateral flow assay for diagnosing periprosthetic joint infection in Asians.

OBJECTIVE: This study aimed to test the accuracy of the Synovasure®, α-defensin lateral flow test kit, in diagnosing periprosthetic joint infections (PJIs) in a predominantly Asian population and to evaluate whether other patient or disease factors may affect its results. METHODS: 61 Asian patients comprising 70 hip or knee prosthetic joints, performed between November 2015 and November 2018, were retrospectively evaluated. Cases were categorized as infected or not infected using Musculoskeletal Infection Society (MSIS) Criteria. Synovial fluid was tested for α-defensin using a commercially available kit. . RESULTS: The Synovasure test had a sensitivity of 73.7% (95% confidence interval (CI): 48.8-90.9%) and specificity of 92.2% (95% CI: 81.1-97.8%) in an Asian population, which was slightly lower compared to previously reported studies in a predominantly Caucasian population. The positive predictive value was 77.8% (95% CI: 56.8-90.3%) and the negative predictive value was 90.4% (95% CI: 81.5-95.2%). The test had an area under curve (AUC) of the receiver operating characteristic (ROC) graph of 0.938, which represents an accuracy that is similar to synovial white blood cells (WBCs) and almost equivalent to that of synovial polymorphonuclear cells (PMNs). The presence of diabetes ( p = 0.26), systemic inflammatory joint disease ( p = 0.33), other metallic implants ( p = 0.53), immunosuppression ( p = 0.13), prior antibiotic usage ( p = 0.99), and chronicity of symptoms ( p = 0.34) was not significantly associated with a positive test in patients with PJI. CONCLUSION: The α-defensin lateral flow test kit is highly accurate in the diagnosis of PJI but with slightly lower sensitivity and specificity in an Asian population when compared with previous studies. The test should be used in conjunction with other MSIS criteria to provide clinically relevant and meaningful results for the diagnosis of PJI.