Tibial plateau fractures are associated with poor functional outcomes and a low conversion rate to total knee arthroplasty.

PURPOSE: The aim of this study was to analyse the functional outcome and the conversion rate to total knee arthroplasty (TKA) after surgically treated tibial plateau fractures (TPF). METHODS: All patients undergoing surgical treatment of TPF at a single institution between January 2003 and December 2019 were retrospectively reviewed. The Knee injury and Osteoarthritis Outcome Score (KOOS) and Tegner activity scale (TAS) were collected. The conversion rate to TKA was examined 2, 5, 7 and 10 years after surgical treatment of TPF. RESULTS: Ninety-four patients, with a mean follow-up of 110.6 months (±60.0), were included in the functional outcome assessment. Mean KOOS scores were 75.4 for symptoms, 80.6 for pain, 84.3 for activities of daily living (ADL), 59.5 for sports and 61.3 for QOL. All subscales were significantly lower on the injured side compared with the contralateral leg. Lower KOOS was observed in patients with hardware removal and Schatzker type 5 and 6 injuries. Median TAS was postinjury (4) significantly lower than preinjury (5) (p < 0.001). The conversion rate to TKA was 6.3%, 10.9%, 11.7% and 12.2% after 2,5,7 and 10 years of follow-up, respectively. Patients undergoing TKA were older than patients with no conversion to TKA (2 years follow-up 53.8 vs. 64.5 years, p = 0.026). CONCLUSION: TPFs decrease the function of the knee when compared with the contralateral side and to the preoperative condition. Bicondylar fractures are associated with worse functional outcomes. A conversion rate to TKA of 12.2% was found at 10 years follow-up. LEVEL OF EVIDENCE: Level III.

Significant Difference in Antimicrobial Resistance of Coagulase Negative Periprosthetic Joint Infection in Septic Revision Total Knee Arthroplasty Between Two Major Orthopedic Centers.

BACKGROUND: Antimicrobial resistance is recognized as a major public health threat. It occurs naturally; however, an excessive antibiotic use and misuse of antibiotics accelerate the process. Periprosthetic joint infections (PJI) are becoming harder to treat as the efficacy of antibiotics is becoming lower. The aim of this study was to compare the resistance of coagulase-negative staphylococci (CNS) to antibiotics identified after revision TKAs for PJI between two major orthopedic centers. METHODS: A review of all revision TKAs, undertaken between 2006 and 2018 in two orthopedic centers, was performed, including all those meeting the consensus criteria for PJI, in which CNS were identified. There were no major differences in surgical approach and tissue sampling between both centers. Thirteen commonly used antibiotics were tested at both centers. RESULTS: The 132 strains were analyzed for their resistance to 13 different antibiotics. Staphylococcus epidermidis was identified in 70.5% cultures, followed by Staphylococcus capitis in 8.3% cultures. The comparison of antibiotic resistance between two centers was statistically significant to penicillin (P = .001), oxacillin (P = .011), cefuroxime (P = .044), levofloxacin (P = .006), moxifloxacin (P = .008), tetracycline (P < .001), rifampicin (P < .001) and vancomycin (P < .001). The difference of resistance of CNS was not statistically significant to fosfomycin, clindamycin, teicoplanin, erythromycin and ampicillin. CONCLUSIONS: The resistance of CNS to antibiotics differs significantly between two major orthopedic centers that are geographically fairly close. Monitoring of bacteriological analyses in each referral center should be continuously performed. Close monitoring is needed for more efficient antibiotic treatment of and prophylaxis against PJI.

High varus stem alignment in short-stem total hip arthroplasty: a risk for reconstruction of femoro-acetabular offset, leg length discrepancy and stem undersizing?

PURPOSE: Short stems are increasingly used in in total hip arthroplasty (THA) because of advantages in bone and soft tissue preservation and reconstruction of hip geometry. Short stems can be inserted in a more varus position compared to conventional straight stems. This poses the risk of final varus misplacement of the femoral component, which is not intended in all femoral short stems. METHODS: We wanted to evaluate the effect of a high varus stem positioning in MIS THA on hip offset, leg length and femoral canal fill index. A series of 1052 consecutive THAs with a singular cementless femoral short stem and press-fit cup was retrospectively screened for inclusion. One hundred six patients with unilateral THA and a contralateral healthy hip met the inclusion criteria. Measurements were carried out on preoperative and 3 months anterior-posterior postoperative radiographs. Patients were divided into Group A (varus stem alignment ≤ 3°) and Group B (varus stem alignment > 3°). RESULTS: Hip offset (HO) increased significantly in Group B by 4 mm (p = 0.013). No influence on leg length difference was detected in both groups. Preoperative CCD angle was significantly lower in Group B (p < 0.001). Canal Fill Indices (CFI) were significantly lower in Group B (CFI I: p < 0.001; CFI II p = 0.003; CF III p = 0.002). CONCLUSION: High varus stem alignment > 3° leads to a statistically significant but minor increase in HO and poses the risk of stem undersizing. A preoperatively low genuine CCD angle pose a risk for varus stem positioning.

Significant Difference in Antimicrobial Resistance of Bacteria in Septic Revision between Total Knee Arthroplasty and Total Hip Arthroplasty.

Antimicrobial resistance (AMR) aggravates the already difficult treatment of periprosthetic joint infections (PJI). Due to many factors influencing AMR, the correct choice of antimicrobial management remains arguable. The primary purpose of this retrospective study was to identify and compare bacteria and their antibiotic resistance profile between septic revision total knee arthroplasty (TKA) and septic revision total hip arthroplasty (THA). A review of all revision TKAs and revision THAs, undertaken between 2007 and 2020 in a tertiary referral hospital, was performed. Included were cases meeting the consensus criteria for PJI, in which an organism has been identified. There were no major differences in tissue sampling between revision TKAs and revision THAs over time. A total of 228 bacterial strains, isolated after revision TKA and THA, were analysed for their resistance to 20 different antibiotics. There was a statistically significant higher occurrence of Gram-negative bacteria identified after revision THAs compared to TKA (p = 0.002). The comparison of antibiotic resistance between revision TKAs and revision THAs was statistically significant in 9 of 20 analysed antibiotics. This has implications for the choice of empirical antibiotic in revision surgery as well as prophylactic antibiotic in primary surgery, depending on the joint that is to be replaced.

Light-chain and transthyretin cardiac amyloidosis in severe aortic stenosis: prevalence, screening possibilities, and outcome.

AIMS: Concomitant cardiac amyloidosis (CA) in severe aortic stenosis (AS) is difficult to recognize, since both conditions are associated with concentric left ventricular thickening. We aimed to assess type, frequency, screening parameters, and prognostic implications of CA in AS. METHODS AND RESULTS: A total of 191 consecutive AS patients (81.2 ± 7.4 years; 50.3% female) scheduled for transcatheter aortic valve replacement (TAVR) were prospectively enrolled. Overall, 81.7% underwent complete assessment including echocardiography with strain analysis, electrocardiography (ECG), cardiac magnetic resonance imaging (CMR), 99m Tc-DPD scintigraphy, serum and urine free light chain measurement, and myocardial biopsy in immunoglobulin light chain (AL)-CA. Voltage/mass ratio (VMR; Sokolow-Lyon index on ECG/left ventricular mass index) and stroke volume index (SVi) were tested as screening parameters. Receiver operating characteristic curve, binary logistic regression, and Kaplan-Meier curve analyses were performed. CA was found in 8.4% of patients (n = 16); 15 had transthyretin (TTR)-CA and one AL-CA. While global longitudinal strain by echo did not reliably differentiate AS from CA-AS [area under the curve (AUC) 0.643], VMR as well as SVi showed good discriminative power (AUC 0.770 and 0.773, respectively), which was comparable to extracellular volume by CMR (AUC 0.756). Also, VMR and SVi were independently associated with CA by multivariate logistic regression analysis (P = 0.016 and P = 0.027, respectively). CA did not significantly affect survival 15.3 ± 7.9 months after TAVR (P = 0.972). CONCLUSION: Both TTR- and AL-CA can accompany severe AS. Parameters solely based on ECG and echocardiography allow for the identification of the majority of CA-AS. In the present cohort, CA did not significantly worsen prognosis 15.3 months after TAVR.