Elmenawi, Khaled A

ABSTRACT Periprosthetic joint infection (PJI) is the most common and difficult to treat form of arthroplasty failure. While treatment with debridement, antibiotics, and implant retention (DAIR) is preferable to one- or two-stage implant exchange based on morbidity and cost, outcomes are not successful in all cases selected for this management strategy. DAIR is currently recommended when infection is perceived to be in an “acute” phase, based on symptom duration; despite this selection strategy, DAIR failure rates are high. A more objective means of predicting DAIR success could improve patient outcomes by limiting DAIR failures. To explore this possibility, advanced proteomic analysis of sonicate fluid samples from 95 subjects with PJI was performed using proximity extension assay (PEA), with 77 samples additionally undergoing complementary proteomics analysis with liquid chromatography with tandem mass spectrometry (LC-MS/MS). Sparse partial least squares differentiation analysis (sPLS-DA) separated samples from patients who underwent DAIR with known outcomes ( n = 19) into successful or unsuccessful groups, predicting DAIR surgical outcome (area under the curve [AUC]: 1; mean “leave one out” AUC: 0.6). Proteins predictive of DAIR surgical outcome were significantly enriched for the “protein repair” Gene Ontology (GO) pathway ( P -adj = 0.02). Additionally, proteomic signatures associated with symptom duration in PJI categorized samples into short and long symptom duration PJI. In summary, an investigation of 7,261 unique human proteins separated PJI-associated samples based on symptom duration and identified a proteomic profile predictive of DAIR success. IMPORTANCE Chronic infections are generally understood to last months to years, with acute infections lasting days to weeks. The transition from acute to chronic infection is, however, poorly understood. Periprosthetic joint infection (PJI) has been considered more challenging to treat when “chronic” than when “acute.” A surgery preferred for its recovery time and cost—debridement, antibiotics, and implant retention (DAIR)—is recommended for PJI management when symptom duration is short; yet, even in this select patient group, DAIR is associated with a high treatment failure rate. A means to better identify those predicted to have a successful outcome if they undergo DAIR is needed. Here, over 7,000 proteins from human clinical PJI samples were measured and shown to be able to separate samples based on symptom duration. Importantly, a proteomic profile predictive of DAIR success was identified.

AbstractHistorically, cementless patellar implants were fraught with issues of fixation and polyethylene wear. However, contemporary cementless patellar implants incorporate modern technologies for implant design and offer the potential for improved biological fixation and longevity. As such, an evaluation of the performance of modern cementless patellae is needed. The purpose of this study was to perform a systematic review and meta-analysis of contemporary cementless patellar implants used during primary total knee arthroplasty (TKA), with a particular focus on aseptic loosening of the patellar component. A systematic review of the literature was performed from January 2000 to February 22, 2024. We included all peer-reviewed studies that reported the number of revisions in patients who had cementless patellae placed in 2000 or later during primary TKA. Reviews and case reports were excluded. Out of 639 studies, 13 were included with a total of 3,005 cementless patellae analyzed. The mean patient age was 64 years and the mean body mass index (BMI) was 31 kg/m2. Meta-analyses were performed to calculate the pooled revision rate per person-year of revision for aseptic loosening of the patellar component and revision for any patellar failure. Upon analysis of 13 studies involving a total of 3,005 cementless patellae, the revision rate for aseptic loosening of the patella was 0.2 per 1,000 person-years and the revision rate for any patellar failure was 1 per 1,000 person-years. Contemporary cementless patellar implants showed an overall revision rate of 1 per 1,000 person-years, demonstrating excellent longevity. The high survivorship, together with a low rate of loosening, show the utility and effectiveness of these implants. Given the nature of biologic fixation, these results are promising for long-term implant stability but additional follow-up is warranted.