Aims. The aims of this study were to develop an in vivo model of periprosthetic joint infection (PJI) in cemented
Abstract. Background. Dislocation of a
Introduction and Objective. Dislocation of a
Between 2016–2019, 4 patients developed hip infections post-hemiarthroplasty. However, between 2020–2021 (Covid-19 pandemic period), 6 patients developed hip infections following
Background.
Gram-negative prosthetic joint infections (GN-PJI) present unique challenges in management due to their distinct pathogenesis of biofilm formation on implant surfaces. To date, there are no animal models that can fully recapitulate how a biofilm is challenged in vivo in the setting of GN-PJI. The purpose of this study is to establish a clinically representative GN-PJI in vivo model that can reliably depict biofilm formation on titanium implant surface. We hypothesized that the biofilm formation on the implant surface would affect the ability of the implant to be osseointegrated. The model was developed using a 3D-printed, medical-grade titanium (Ti-6Al-4V), monoblock, cementless hemiarthroplasty hip implant. This implant was used to replace the femoral head of a Sprague-Dawley rat using a posterior surgical approach. To induce PJI, two bioluminescent Pseudomonas aeruginosa (PA) strains were utilized: a reference strain (PA14-lux) and a mutant strain that is defective in biofilm formation (DflgK-lux). PJI development and biofilm formation was quantitatively assessed in vivo using the in vivo imaging system (IVIS), and in vitro using the viable colony count of the bacterial load on implant surface. Magnetic Resonance Imaging (MRI) was acquired to assess the involvement of periprosthetic tissue in vivo, and the field emission scanning electron microscopy (FE-SEM) of the explanted implants was used to visualize the biofilm formation at the bone-implant interface. The implant stability, as an outcome, was directly assessed by quantifying the osseointegration using microCT scans of the extracted femurs with retained implants in vitro, and indirectly assessed by identifying the gait pattern changes using DigiGaitTM system in vivo. A localized prosthetic infection was reliably established within the hip joint and was followed by IVIS in real-time. There was a quantitative and qualitative difference in the bacterial load and biofilm formation between PA14 and DflgK. This difference in the ability to persist in the model between the two strains was reflected on the gait pattern and implant osseointegration. We developed a novel uncemented
Introduction. Gram-negative prosthetic joint infections (GN-PJI) present unique challenges in management due to their distinct pathogenesis of biofilm formation on implant surfaces. The purpose of this study is to establish a clinically representative GN-PJI model that can reliably recapitulate biofilm formation on titanium implant surface in vivo. We hypothesized that biofilm formation on an implant surface will affect its ability to osseointegrate. Methods. The model was developed using 3D-printed titanium hip implants, to replace the femoral head of male Sprague-Dawley rats. GN-PJI was induced using two bioluminescent Pseudomonas aeruginosa strains: a reference strain (PA14-lux) and a mutant biofilm-defective strain (ΔflgK-lux). Infection was monitored in real-time using the in vivo imaging system (IVIS) and Magnetic Resonance Imaging (MRI). Bacterial loads on implant surface and in periprosthetic tissues were quantified utilizing viable-colony-count. Field-emission scanning-electron-microscopy of the explanted implants was used to visualize the biofilm formation at the bone-implant-interface. The implant stability, as an outcome, was directly assessed by quantifying the osseointegration in vitro using microCT scan, and indirectly assessed by identifying the gait pattern changes using DigiGait. TM. system in vivo. Results. Localized infection was established within the hip joint and was followed by IVIS in real-time. There was a quantitative and qualitative difference in the bacterial load and biofilm formation between PA14-lux and ΔflgK-lux. This difference in the ability to persist in the model between the two strains was reflected in the gait pattern and implant osseointegration. Conclusions. We developed a novel uncemented
Prosthetic joint infections (PJI) are devastating complications. Our knowledge on
Introduction. The
Introduction. Premature cessation of clopidogrel in certain patients with cardiac conditions is associated with an increased risk of recurrent coronary events. Such patients often present with proximal femoral fractures requiring surgical intervention. Our aim was to ascertain whether it is necessary to stop clopidogrel preoperatively to avoid postoperative complications following
Introduction and Objective. Interest for direct anterior approach (DAA) in
The aims of this study were to determine the incidence and factors for developing periprosthetic joint infection (PJI) following hemiarthroplasty (HA) for hip fracture, and to evaluate treatment outcome and identify factors associated with treatment outcome. A retrospective review was performed of consecutive patients treated for HA PJI at a tertiary referral centre with a mean 4.5 years’ follow-up (1.6 weeks to 12.9 years). Surgeries performed included debridement, antibiotics, and implant retention (DAIR) and single-stage revision. The effect of different factors on developing infection and treatment outcome was determined.Aims
Methods
Aims: Research was preformed including evaluation of early functional and radiographic results, six months after operative treatment of femoral neck fracture, using hemiarthroplasty and osteosynthesis, and late results, two years and more after operation. Methods: Clinical material comprehended two groups of hundred unselected patients each. Control exams included anamnestic data, and radiographic studies of treated hip. Data were stored in previously prepared research protocol according to applied functional and radiographic scoring systems. Results: Data were analized and compared between groups. Results of
Recent National Institute for Health and Care Excellence (NICE) guidance has advised against the continued use of the Thompson implant when performing
Aim. To review the outcome of deep prosthetic infection in patients following
Hip fractures are frequent due to osteoporosis and old age. The incidence of the second hip fracture had been reported as 5–9%. Subcapital displaced fractures in the elderly are treated sometimes with
Introduction. Geometric variations of the hip joint can give rise to abnormal joint loading causing increased stress on the articular cartilage, which may ultimately lead to degenerative joint disease. In-vitro simulations of total hip replacements (THRs) have been widely reported in the literature, however, investigations exploring the tribology of two contacting cartilage surfaces, and cartilage against metal surfaces using complete hip joint models are less well reported. The aim of this study was to develop an in-vitro simulation system for investigating and comparing the tribology of complete natural hip joints and hemiarthroplasties with THR tribology. The simulation system was used to assess natural porcine hip joints and porcine
Introduction: The objective of our study was to analyse the incidence of subsidence of an uncemented, hydroxyapatite coated, collarless prosthesis (Orthodynamics) and its impact on postoperative mobility in patients with fractured neck of femur. Methods: 22 sets of case notes and X Rays were available for patients treated with the Orthodynamics hemiarthroplasty between February and November 2005. The mean age was 78 years (range 61 – 91 years). Analysis of standardised anteroposterior radiographs in the immediate postoperative period and at a mean interval of 14 weeks (ranging from 6 weeks to 64 weeks) was undertaken. Subsidence was calculated by measuring the reduction in the distance between the tip of lesser trochanter and a fixed point on the prosthesis. Results: 18 of the 22 (81.8 %) cases showed subsidence of the prosthesis. The mean subsidence calculated was 9.1 millimetres (range 1 to 25 millimetres) and it showed no relationship to the postoperative interval at which it was calculated. Impact of subsidence on mobility state was assessed. Post operative mobility status was available for sixteen patients. Nine patients showed no change in the mobility at follow up. This group had a mean subsidence of 4.3 mm. Seven patients had a worsening of their mobility state. The mean subsidence in this group was 10.1 mm. Discussion: Our study shows significant subsidence of an uncemented, collarless, hydroxyapatite coated prosthesis used for
Abstract. Objectives. Up to 19% of patients who undergo surgery for an acute hip fracture are readmitted to the hospital within three months of the index operation. We aimed to identify risk factors for unplanned clinic attendance, readmission, and mortality within the first 12 months postoperatively and subsequently determine if there is a role for routine follow-up. Methods. Patients greater than 65 years old who underwent
Deep surgical site infection (SSI) remains an unsolved problem after hip fracture. Debridement, antibiotic, and implant retention (DAIR) has become a mainstream treatment in elective periprosthetic joint infection; however, evidence for DAIR after infected hip hemiarthroplaty is limited. Patients who underwent a hemiarthroplasty between March 2007 and August 2018 were reviewed. Multivariable binary logistic regression was performed to identify and adjust for risk factors for SSI, and to identify factors predicting a successful DAIR at one year.Aims
Methods