Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant ( In vitro, interleukin-1 beta (IL-1β) was used to establish the mice OA chondrocytes. Cell counting kit-8 evaluated chondrocyte viability. Western blotting analyzed the expression levels of collagen II, aggrecan, SOX9, inducible nitric oxide synthase (iNOS), IL-6, matrix metalloproteinases (MMPs: MMP1, MMP3, and MMP13), and signalling molecules associated with nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Immunofluorescence analysis assessed the expression of aggrecan, collagen II, MMP13, and p-P65. In vivo, a destabilized medial meniscus (DMM) surgery was used to induce mice OA knee joints. After injection of DHCA or a vehicle into the injured joints, histological staining gauged the severity of cartilage damage.Aims
Methods
Pellino1 (Peli1) has been reported to regulate various inflammatory diseases. This study aims to explore the role of Peli1 in the occurrence and development of osteoarthritis (OA), so as to find new targets for the treatment of OA. After inhibiting Peli1 expression in chondrocytes with small interfering RNA (siRNA), interleukin (IL)-1β was used to simulate inflammation, and OA-related indicators such as synthesis, decomposition, inflammation, and apoptosis were detected. Toll-like receptor (TLR) and nuclear factor-kappa B (NF-κB) signalling pathway were detected. After inhibiting the expression of Peli1 in macrophages Raw 264.7 with siRNA and intervening with lipopolysaccharide (LPS), the polarization index of macrophages was detected, and the supernatant of macrophage medium was extracted as conditioned medium to act on chondrocytes and detect the apoptosis index. The OA model of mice was established by destabilized medial meniscus (DMM) surgery, and adenovirus was injected into the knee cavity to reduce the expression of Peli1. The degree of cartilage destruction and synovitis were evaluated by haematoxylin and eosin (H&E) staining, Safranin O/Fast Green staining, and immunohistochemistry.Aims
Methods
Septic arthritis is a painful infection of articular joints that is typically treated by irrigation & debridement along with antibiotic therapy. There is debate amongst the medical community whether antibiotic administration should be delayed until fluid cultures have been taken to improve culture yield. However, delaying antibiotics can also have negative consequences, including joint destruction and sepsis. Therefore, the purposes of this study were to determine: 1) whether delayed antibiotic treatment affects culture yield and prognosis and 2) if the culture yield of patients treated for septic arthritis differs for hip, knee, and shoulder based on timing of antibiotic administration. A retrospective analysis was conducted on 111 patients with septic arthritis of the hip, knee, or shoulder admitted from 3/2016 to 11/2018. In patients with multiple septic joints, each joint was analyzed individually (n=122). Diagnosis was determined by the treatment of irrigation & debridement and/or a positive culture. Patients without all intervention times recorded or with periprosthetic joint infection were excluded. Demographics, laboratory tests, culture results, and intervention times were obtained through chart review. Patients were grouped based on antibiotic therapy timing: >24 hours prior to arthrocentesis (Group 1), between 24 hours and 1 hour prior (Group 2), and 1 hour prior to post-arthrocentesis (Group 3). Analysis was conducted using chi-squared tests.Aim
Method
To evaluate the effect of ultrasound-targeted simvastatin-loaded microbubble destruction (UTMD In vitro, OA chondrocytes were treated with ultrasound (US), US-targeted microbubble destruction (UTMD), simvastatin (SV), and UTMDAims
Methods
Periprosthetic joint infections (PJIs) and osteomyelitis are clinical challenges that are difficult to eradicate. Well-characterized large animal models necessary for testing and validating new treatment strategies for these conditions are lacking. The purpose of this study was to develop a rabbit model of chronic PJI in the distal femur. Fresh suspensions of Aims
Methods
Mechanical loosening of total hip replacement (THR) is primarily diagnosed using radiographs, which are diagnostically challenging and require review by experienced radiologists and orthopaedic surgeons. Automated tools that assist less-experienced clinicians and mitigate human error can reduce the risk of missed or delayed diagnosis. Thus the purposes of this study were to: 1) develop an automated tool to detect mechanical loosening of THR by training a deep convolutional neural network (CNN) using THR x-rays, and 2) visualize the CNN training process to interpret how it functions. A retrospective study was conducted using previously collected imaging data at a single institution with IRB approval. Twenty-three patients with cementless primary THR who underwent revision surgery due to mechanical loosening (either with a loose stem and/or a loose acetabular component) had their hip x-rays evaluated immediately prior to their revision surgery (32 “loose” x-rays). A comparison group was comprised of 23 patients who underwent primary cementless THR surgery with x-rays immediately after their primary surgery (31 “not loose” x-rays). Fig. 1 shows examples of “not loose” and “loose” THR x-ray. DenseNet201-CNN was utilized by swapping the top layer with a binary classifier using 90:10 split-validation [1]. Pre-trained CNN on ImageNet [2] and not pre-trained CNN (initial zero weights) were implemented to compare the results. Saliency maps were implemented to indicate the importance of each pixel of a given x-ray on the CNN's performance [3].INTRODUCTION
METHODS
Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes. Robotic-assisted (RA) total knee arthroplasty has demonstrated improved accuracy to plan in cadaver studies compared to conventionally instrumented (manual) TKA, but less clinical evidence has been reported. The objective of this study was to compare the three-dimensional accuracy to plan of RATKA with manual TKA for overall limb alignment and component position. A non-randomized, prospective multi-center clinical study was conducted to compare RATKA and manual TKA at 4 U.S. centers between July 2016 and August 2018. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons’ operative plan for overall limb, femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. We tested the differences of absolute deviation from plan between manual and RATKA groups using stratified Wilcoxon tests, which controlled for study center and accounted for skewed distributions of the absolute values. Alpha was 0.05 two-sided. At the time of this abstract, data collections were completed for two centers (52 manual and 58 RATKA).Introduction
Methods
Knee arthrodesis (KA) and above knee amputation (AKA) have been used for salvage of failed total knee arthroplasty (TKA) in the setting of periprosthetic joint infection (PJI). The factors that lead to a failed fusion and progression to AKA are not well understood. The purpose of our study was to determine factors associated with failure of a staged fusion for PJI and predictive of progression to AKA. We retrospectively reviewed a single-surgeon series of failed TKA for PJI treated with two-stage KA between 2000 and 2016 with minimum 2-year follow-up. Patient demographics, comorbidities, surgical history, tissue compromise, and radiographic data were recorded. Outcomes were additional surgery, delayed union, Visual Analog Pain scale (VAS) and Western Ontario and McMaster Activity score (WOMAC). No power analysis was performed for this retrospective study. Medians are reported as data were not normally distributed.Aim
Method
Traditionally, serum white blood count (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been utilized as markers to evaluate septic arthritis (SA). Recently, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified as prognostic factors for treatment failure, mortality and morbidity in various clinical settings. To date, these markers have not been utilized for evaluating outcomes after hip and knee SA. Thus, the purpose of this study was to determine the ability of admission NLR and PLR to predict treatment failure and postoperative 90-day mortality in hip and knee SA. A retrospective study was performed using our institutional research patient database to identify 235 patients with native hip and knee septic arthritis from 2000–2018. Patient demographics, comorbidities and social factors (alcohol intake, smoking and intravenous drug use) were obtained, and NLR and PLR were calculated based on complete blood count values (absolute neutrophil, lymphocyte and platelet count) on admission. Treatment failure was defined as any reoperation or readmission within 90 days after surgery. Receiver operating curves were analyzed, and optimal thresholds for NLR and PLR were determined using Youden's test. Univariate and multivariate analyses were performed to determine if these ratios were independent predictors of treatment failure and 90-day mortality after surgery. These ratios were compared to serum WBC, CRP, and ESR.Aim
Method
Peri-operative hyperglycemia has many etiologies, including medication, impaired glucose tolerance, uncontrolled diabetes mellitus (DM), or stress, the latter of which is common in post-surgical patients. Our study aims were to investigate if post-operative day 1 (POD1) blood glucose level was associated with post-operative complications after total joint arthroplasty (TJA), including periprosthetic joint infection (PJI), and to determine a threshold for glycemic control that surgeons should strive for during a patient's hospital stay. A single-institution retrospective review was conducted on 24,857 primary TJAs performed from 2001–2015. Of these, 13,198 had a minimum one-year follow-up (mean 5.9 years). Demographics, Elixhauser comorbidities, laboratory values, complications and readmissions were collected. POD1 morning blood glucose levels were utilised and correlated with PJI, as defined by the Musculoskeletal Infection Society criteria. The mean age and body mass index of the population was 63.4 years and 30.2 kg/m2, respectively; the sample was comprised of 56.6% females and 48.4% knees. Multivariate analysis was used to determine the influence of several important covariates on complication rate. Youden's J statistic was utilised to determine an optimal blood glucose threshold. An alpha level of 0.05 was used to determine statistical significance.Introduction
Methods
Tibial and femoral component overhang in total knee arthroplasty (TKA) is a source of pain, thus is it important to understand anatomic differences between races to minimize overhang by matching the tibial and femoral shaft axis to the knee articular surface. Thus, this study compared knee morphology between Caucasian and East Asian individuals to determine the optimal placement of tibial and femoral stems. A retrospective study was conducted on a matched cohort of 50 East Asians (21F, 29M) and 50 Caucasians (21F, 29M) by age and gender. CT scans were obtained in healthy volunteers using <2mm slices. The distance from the proximal tibial diaphysis axis to the tibial plateau center was measured, and the distance from the distal femoral diaphysis axis to the center of distal femoral articular surface was measured. Tibial measurements were made using Akagi's AP axis and the widest ML diameter, and femoral measurements were based on Whiteside's line and the surgical epicondylar axis.Purpose
Methods
The direct anterior approach (DAA) for total hip arthroplasty (THA) is marketed with claims of superiority over other approaches. Femoral exposure can be technically challenging and potentially lead to early failure. We examined whether surgical approach is associated with early THA failure. A retrospective review of 478 consecutive early revision THAs within five years of primary THA at three academic centers from 2011 through 2014 was performed. Exclusion criteria resulted in a final analysis sample of 341 early failure THAs. Primary surgical approach was documented for each revision, along with time to revision, and failure etiology.Background
Methods
Sequentially annealed, highly crosslinked polyethylene (HXLPE) has been used clinically in total knee arthroplasty (TKA) for over a decade[1]. However, little is known about the reasons for HXLPE revision, its surface damage mechanisms, or its Four hundred and fifty-six revised tibial inserts in two cohorts (sequentially annealed and conventional UHMWPE control) were collected in a multicenter retrieval program between 2000 and 2016. We controlled for implantation time between the two cohorts by excluding tibial inserts with a greater implantation time than the longest term sequentially annealed retrieval (9.5 years). The mean implantation time (± standard deviation) for the sequentially annealed components was 1.9 ± 1.7 years, and for the control inserts, 3.4 ± 2.7 years (Figure 1). Reasons for HXLPE revision were assessed based on medical records, radiographs, and examinations of the retrieved components. Surface damage mechanisms were assessed using the Hood method[2]. Oxidation was measured at the bearing surface, the backside surface, the anterior and posterior faces, as well as the post (when available) using FTIR (ASTM F2102). Surface damage and oxidation analyses were available for 338 of the components. We used nonparametric statistical testing to analyze for differences in oxidation and surface damage when adjusting for polyethylene formulation as a function of implantation time.Background
Methods
During revision surgery with a well-fixed stem, a titanium sleeve can be used in conjunction with a ceramic head to achieve better stress distribution across the taper surface. Previous studies have observed that the use of a ceramic head can mitigate the extent of corrosion damage at the taper. Moreover, Thirty sleeved ceramic heads (Biolox Option: CeramTec) were collected during revision surgery as part of a multi-center retrieval program. The sleeves were used in conjunction with a zirconia-toughened alumina femoral head. The femoral heads and sleeves were implanted between 0.0 and 3.25 years (0.8±0.9, Figure 1). The implants were revised predominantly for instability (n=14), infection (n=7), and loosening (n=5). Fifty percent of the retrievals were implanted during a primary surgery, while 50% had a history of a prior revision surgery. Fretting corrosion was scored using a previously described 4-point, semi-quantitative scoring system proposed by Higgs [2].Introduction
Materials and Methods
Diffuse noxious inhibitory control (DNIC) works through the “pain-inhibits-pain” principle in which an additional painful (conditioned) stimulus can suppress the initial experienced pain through the descending and inhibiting pathways. Painful stimulation produced less pain inhibition in patients with knee osteoarthritis patients (KOA) than in controls, suggesting an impaired DNIC function and a loss of endogenous pain modulation. Electroacupuncture (EA) is widely used to treat acute pain associated with KOA, but the available evidence of its benefit on chronification of acute pain is scarce. This is a single-arm clinical study aims to evaluate the effect of EA on the chronification of pain associated with KOA and provide a profile of various cytokines underlying the pathogenesis of KOA. Participants are recruited through hospital-based recruitment and advertisements, diagnosis was based upon the criteria formulated by the American College of Rheumatology. Each participant was administered with EA (2 mA < current < 5 mA) at the ipsilateral EX-LE5, ST35, ST34 and SP10 for two weeks (once a day, 30 minutes per session, in 5 sessions per week). Visual Analog Scale (VAS), DNIC function, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Numerical Rating Scale (NRS), Emotional Scale (ES) and Present Pain Intensity (PPI) are evaluated before treatment and after 5 to 10 sessions of treatment. Cytokines including GRO, TNF-α, VEGF, IP-10, IL-1β, IL-17, IL-8, MCP-1 and IL-10 levels in plasma were measured using a Human Cytokine/Chemokine Magnetic Bead Panel on MAGPIX instrument before and after two weeks of treatment. A total of 39 patients with KOA were enrolled in our study (age: 63.46±9.89 years; height: 1.63±0.07 m; BMI: 22.83±2.89), all of them completed the trial. After 5 sessions of EA treatment, a significant decrease of VAS, WOMAC scores, NRS, ES and PPI was detected, but no significant difference in DNIC was observed. After two weeks' treatment, all clinical parameters (VAS, DNIC, WOMAC, NRS, ES, PPI) reduced significantly when compared with baseline; GRO, IL-17A, IL-1b, IL-8, MCP-1, TNF-a, VEGF levels in plasma reduced significantly while IL-10 and IP-10 concentrations were elevated. This study appeared to provide evidence that EA was effective in improving chronic pain associated with KOA through repairing the impaired DNIC function and down-regulation of OA detrimental cytokines. A randomized controlled prospective study with large sample size is required to clarify the effect of EA in reversing the chronification of pain in KOA.
Hospital systems have recently instituted early systemic sepsis recognition systems, where vital signs and laboratory findings are monitored and automatically alert providers to potential sepsis. Although there are very few reports evaluating the use of sepsis alert systems outside of the emergency room or intensive care unit, many hospital systems have made the decision to apply the sepsis alarm protocols to all inpatients. The purpose of this study was to evaluate if an alarm system using systemic inflammatory response syndrome (SIRS) criteria is a valuable tool to predict systemic sepsis in the immediate postoperative period (POD#0–4) after total joint arthroplasty (TJA). 10,791 primary and revision TJA patients at one institution, from 2010–2014, were retrospectively reviewed for positive SIRS criteria on each hospital day from the date of surgery to postoperative day four (POD#4). SIRS criteria included temperature > 38°C or < 36°C, heart rate > 90 beats per minute, respiratory rate > 20 breaths per minute, and white blood cell (WBC) > 12,000/mm3 or < 4,000/mm3. Additionally, hospital coding data was cross-referenced to identify patients who were diagnosed with systemic sepsis within 10 days after having a TJA.Aim
Method
Different perioperative strategies have been implemented to reduce the devastating burden of infection following arthroplasty. The use of iodophor-impregnated adhesive incise drapes is one such strategy. Despite its wide adoption, there is little proof that this practice leads to a reduction of bacterial colonization. The aim of this randomized, prospective study was to evaluate the efficacy of iodophor-impregnated adhesive drapes for reducing bacterial count at the incision site. A total of 96 patients undergoing open joint preservation procedure of the hip were enrolled in this prospective, randomized clinical trial of iodophor-impregnated adhesive drapesAim
Method
Perioperative hyperglycemia has many etiologies including medication, impaired glucose tolerance, uncontrolled diabetes mellitus (DM), or stress, the latter of which is common to post-surgical patients. This acute hyperglycemia may impair the ability of the host to combat infection.1 Our study aims to investigate if post-operative day 1 (POD1) blood glucose level is associated with complications, including periprosthetic joint infection (PJI), after total joint arthroplasty (TJA) and to determine a threshold for glycemic control that surgeons should strive for during a patient's hospital stay. A single-institution retrospective review was conducted on 24,857 primary TJAs performed from 2001–2015. Demographics, Elixhauser comorbidities, laboratory values, complications and readmissions were collected. POD1 morning blood glucose levels were utilized and correlated with PJI, as defined by the Musculoskeletal Infection Society criteria. The Wald test was used to determine the influence of covariates on complication rate. An alpha level of 0.05 was used to determine statistical significance.Aim
Method
Previous studies of long-term CoCr alloy femoral components for TKA have identified 3rd body abrasive wear and inflammatory cell induced corrosion (ICIC). The extent of femoral condyle surface damage in contemporary CoCr femoral components is currently unclear. The purpose of this study was to investigate the prevalence and morphology of damage (3rd body scratches and ICIC) at the bearing surface in retrieved TKA femoral components from contemporary designs. 308 CoCr femoral TKA components were collected as part of an ongoing, multi-institutional orthopedic implant retrieval program. The collection included contemporary designs from Stryker (Triathlon n=48, NRG n=10, Scorpio n=31), Depuy Synthes (PFC n=27) and Zimmer (NexGen n=140, Persona n=1) and Biomet (Vanguard n=51). Hinged knee designs and unicondylar knee designs were excluded. Components were split into groups based on implantation time: short-term (1–3y, n=134), intermediate-term (3–5y, n=73) and long-term (6–15y, n=101). Each grouping was mainly revised for instability, infection and loosening. Third-body abrasive wear of CoCr was evaluated using a semi-quantitative scoring method similar to the Hood method (Figure 1). A score of 1 had minimal damage and a score of 4 corresponded to damage covering more than 50% of the evaluated area. ICIC damage was reported as location of affected area. A white light interferometer (Zygo New View 5000) was also used to analyze the topography of severe damage of the bearing surface. For this analysis, three representative components from each cohort were selected and analyzed in three locations on the apex of the bearing surface. We analyzed the following roughness parameters: Ra, Rsk, and Rku.Introduction
Methods
Highly crosslinked polyethylene (HXLPE) was clinically introduced approximately a decade and a half ago to reduce polyethylene wear rates and subsequent osteolysis. Clinical and radiographic studies have repeatedly shown increased wear resistance, however concerns of rim oxidation and fatigue fracture remain. Although short to intermediate term retrieval studies of these materials are available, the long-term behavior of these materials remains unclear. Between 2000 and 2015, 115 1st generation HXLPE acetabular liners implanted for 5 or more years were collected and analyzed as part of an ongoing, multi-institutional orthopaedic implant retrieval program. There were two material cohorts based on thermal processing (annealed (n=45) and remelted (n=70)). Each cohort was stratified into two more cohorts based on implantation time (5 – 10 years and >10 years). For annealed components, the intermediate-term liners (n=30) were implanted on average (±SD) for 7.3 ± 1.7 years while the long-term liners (n=15) were implanted for 11.3 ± 1.8 years. For remelted components, the intermediate-term liners (n=59) were implanted on average (±SD) for 7.2 ± 1.3 years while the long-term liners (n=11) were implanted for 11.3 ± 1.2 years. For each cohort, the predominant revision reasons were loosening, instability, and infection (Figure 1). Short-term liners (in-vivo <5ys) from previous studies were analyzed using the same protocol for use as a reference. For oxidation analysis, thin slices (∼200 μm) were taken from the superior/inferior axis and subsequently boiled in heptane for 6 hours to remove absorbed lipids that may interfere with the oxidation analysis. 3mm line profiles (in 100μm increments) were taken perpendicular to the surface at each region of interest. Oxidation indices were calculated according to ASTM 2102. Penetration was measured directly using a calibrated micrometer (accuracy=0.001mm).Introduction
Methods
Previous studies of retrieved CoCr alloy femoral heads have identified imprinting of the stem taper surface features onto the interior head bore, leading researchers to hypothesize that stem taper microgrooves may influence taper corrosion. However, little is known about the role of stem taper surface morphology on the magnitude of in vivo corrosion damage. We designed a matched cohort retrieval study to examine this issue. From a multi-institutional retrieval collection of over 3,000 THAs, 120 femoral head-stem pairs were analyzed for evidence of fretting and corrosion using a visual scoring technique based on the severity and extent of fretting and corrosion damage observed at the taper. A matched cohort design was used in which 60 CoCr head-stem pairs with a smooth stem taper were matched with 60 CoCr head-stem pairs having a micro-grooved surface, based on implantation time, flexural rigidity, apparent length of taper engagement, and head size. This study was adequately powered to detect a difference of 0.5 in corrosion scores between the two cohorts, with a power of 82% and 95% confidence. Both cohorts included CoCr and Ti-6-4 alloy femoral stems. A high precision roundness machine (Talyrond 585, Taylor Hobson, UK) was used to measure surface morphology and categorize the stem tapers into smooth vs. micro-grooved categories. Fretting and corrosion damage at the head/neck junction was characterized using a modified semi-quantitative adapted from the Goldberg method by three independent observers. This method separated corrosion damage into four visually determined categories: minimal, mild, moderate and severe damage.Introduction
Methods
It is strongly recommended that tissue and synovial fluid culture samples be obtained during reimplantation performed as part of a two-stage exchange arthroplasty. The incidence of positive cultures during reimplantation and the influence of positive cultures on subsequent outcome are unknown. This aim of this study was to determine the incidence of positive cultures during reimplantation and to investigate the association between positive cultures at reimplantation and the subsequent outcome A retrospective review was conducted on 267 patients that met the Musculoskeletal Infection Society (MSIS) criteria for PJI that completed both stages of two-stage exchange arthroplasty (Table 1). Intraoperative culture results from tissue and/or synovial fluid were obtained. Cultures were positive in 33 cases (12.4%) undergoing reimplantation surgery (Figure 1). Treatment failure was assessed based on the Delphi consensus definition. Logistic regression analysis was performed to assess the predictors of positive culture and risk factors for failure of two-stage exchange arthroplasty. Treatment failure was 45.5% for those with a positive intraoperative culture and 20.9% in those with negative cultures at the time of reimplantation. When controlling for organism virulence, comorbidities, and other confounding factors, treatment failure was higher (odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.3–4.5) and occurred at an earlier time point (hazard ratio: 2.5; 95% CI: 1.3–4.5) in patients with a positive reimplantation culture. The treatment failure rate was not different between cases with two or more positive cultures (36.4%) and one positive culture (42.8%). Positive intraoperative cultures during reimplantation, regardless of the number of positive samples were independently associated with two times the risk of subsequent infection and earlier treatment failure. Surgeons should be aware that a positive culture at the time of reimplantation independently increases the risk of subsequent failure and needs to be taken seriously. Given the significance of these findings, future studies are needed to evaluate the optimal management of positive cultures during reimplantation surgery.
Perioperative antibiotic prophylaxis remains one of the most important strategies for prevention of periprosthetic joint infection (PJI) with current guideline recommending a first or second generation cephalosporin. Penicillin (PCN) allergy is often reported by patients, which often results in avoidance of administration of cephalosporins due to fear of cross-reactivity. Alternative medications, such as vancomyin, are often used despite reduced antimicrobial coverage. The purpose of this study was to determine if PCN allergic patients who received vancomycin alone prior to elective primary total joint arthroplasty were at increased risk of developing a subsequent PJI. A retrospective review of 7,602 primary total joint arthroplasties (TJAs) performed between 2005 and 2013 in two institutions were identified using a prospective institutional database. Patient reported PCN or cephalosporin allergy was electronically queried from the anesthesia note. Patients who recieved multiple prophylactic antibiotics, or had unavailable perioperative antibiotic information, or those who received medication other than cefazolin and vancomycin were excluded. PJI was determined using a cross-match with an institutional PJI database constructed from International Classification of Diseases (ICD)-9 codes. Logistic regression analysis was then performed to evaluate the risk of subsequent PJI. The rate of PJI was 1.4% (32/2296) in patients with a reported PCN allergy that received vancomycin alone versus 1.1% (59/5306) in non-PCN allergic patients that received cefazolin alone. The multivariate analysis, with the given sample size, did not detect a statistically significant increased risk of PJI when vancomycin was administered alone (adjusted odds ratio: 1.23, 95% CI 0.6–3.1, p=0.35). While there was no significant differences in the organism profile between PJIs in both groups, the rate of PJI caused by resistant organisms was higher in patients who received vancomycin alone (11.9%, 7/59) compared to those who received cefazolin (3.1%, 1/32). While administration of perioperative prophylactic vancomycin alone during elective primary arthroplasty does not seem to result in a higher rate of subsequent PJI, patients who received vancomycin alone and developed a PJI were more likely to develop an infection with an antibiotic resistant organism. Future studies are needed to determine the most appropriate prophylactic antibiotic for patients who undergo elective arthroplasty and report PCN allergy.
Considerable efforts have been invested into identifying risk factors for periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). Preoperative identification of risk factors for developing PJI is imperative for medical optimization and targeted prophylaxis. The purpose of this study was to create a preoperative risk calculator for PJI by assessing a patient's individual risks for developing PJI with resistant organisms and S.aureus. A retrospective review of 27117 patients (43253 TJAs) from 1999 to 2014, including 1035 PJIs, was performed. A total of 41 risk factors including demographics, comorbidities (using the Elixhauser and Charlson Index), and the number of previous TJAs, were evaluated. Multivariate analysis was performed; coefficients of the models were scaled to produce useful integer scoring. Predictive model strength was assessed employing area under the curve (AUC) analysis. Among the 41 assessed variables, the following were significant risk factors in descending order of significance: prior surgeries (p<0.0001), drug abuse (p=0.0003), revision surgery (p<0.0001), human immunodeficiency virus (p=0.0004), coagulopathy (p<0.0001), renal disease (p<0.0001), congestive heart-failure (p<0.0001), psychoses (p=0.0024), rheumatological disease (p<0.0001), knee involvement (p<0.0001), diabetes (p<0.0001), anemia (p<0.0001), males (p<0.0001), liver disease (p=0.0093), smoking (p=0.0268), and high BMI (p<0.0001). Furthermore, presence of heart-valve disease (p=0.0409), metastatic disease (p=0.0006), and pulmonary disease (p=0.0042) increased the resistant organism PJIs. Patients with metastatic disease were also more likely to be infected with S. aureus (p=0.0002). AUCs were 0.83 for any PJI, 0.86 for resistant PJI, and 0.84 for S.aureus PJI models. This large-scale single-institutional study has determined various risk factors for PJI. Some factors are modifiable and need to be addressed before elective arthroplasty. It is imperative that surgeons are aware of these risk factors and implement all possible preventative measures, including targeted prophylaxis, in patients with high-risk of PJI. Continued efforts are needed to find novel and effective solutions to minimize the burden PJI.
Periprosthetic joint infection (PJI) is one of the most devastating complications of total joint arthroplasty (TJA). Only a few studies have investigated PJI's impact on the most worrisome of all endpoints, mortality. The purpose of this study was to perform a large-scale study to determine the rates of PJI associated in-hospital mortality, and compare it to other surgical procedures. The Nationwide Inpatient Sample was queried from 2002 to 2010 to assess the risk of mortality for patients undergoing revision for PJI or aseptic failures. Elixhauser comorbidity index and ICD-9 codes were used to obtain patients’ medical conditions and identify PJI. Multiple logistic-regression analyses were used to determine the associated variables with mortality. In-hospital mortality was compared to the followings: coronary-artery bypass graft, mastectomy, prostatectomy, appendectomy, kidney transplant, carotid surgery, cholecystectomy, and coronary interventional procedures. PJI was associated with an increased risk (odds ratio 2.04) of in-hospital mortality (0.77%) compared to aseptic revisions (0.38%). The in-hospital mortality of revision THAs done for PJI (1.38%, 95%CI, 1.12–1.64%) was comparable to or higher than interventional coronary procedure (1.22%, 95%CI, 1.20–1.24%), cholecystectomy (1.13%, 95%CI, 1.11–1.15%), kidney transplantation (0.70%, 95%CI, 0.61%–0.79%) and carotid surgery (0.89%, 95%CI, 0.86%–0.93%) (Figure 1). The following comorbidities were independent risk factors for in-hospital mortality after TJA: liver disease, metastatic disease, fluid and electrolyte disorders, coagulopathy, weight loss and malnutrition, congestive heart failure, pulmonary circulation disorder, renal failure, and peripheral vascular disease. PJI is associated with a two-fold increase in mortality and have mortality rates comparable to kidney transplantation and carotid surgery. Considering the fact that patients with PJI often require multiple surgical procedures, the rate of actual in-hospital mortality for patients with PJI may be considerably higher. Surgeons should be cognizant of the potentially fatal outcome of PJI and must emphasize the importance of infection control to reduce the risk of mortality.
Preoperative antibiotic prophylaxis remains one of the most important strategies for preventing periprosthetic joint infection (PJI). Current guidelines recommend giving universal antibiotic prophylaxis to all total joint arthroplasty (TJA) patients regardless of their medical conditions or immune status. The aims of this study were to determine if comorbidities influence the organism profile of PJIs and to investigate if the efficacy of the two most frequently used perioperative antibiotics (cefazolin or vancomycin) are affected by patient comorbidities. Using an institutional database, the influence of comorbidities on the organism profile of 1022 PJIs was evaluated. To investigate the influence of perioperative antibiotic monotherapy (cefazolin or vancomycin therapy) on PJI, 8575 primary TJAs were identified and analyzed based on their comorbidities. Patients with multiple perioperative antibiotics, prior septic arthritis, unavailable perioperative antibiotic information, or who underwent aseptic revision were excluded. PJI was determined from ICD-9 codes. While no comorbidities were associated with an increased rate of gram-positive or gram-negative infections, metastatic disease (odds ratio [OR] 7.54, p=0.006), rheumatologic disease (OR 1.63, p=0.046), and chronic pulmonary disease (OR 1.46, p=0.030) demonstrated an increased risk of Staphylococcus aureus PJI. In addition, metastatic disease (OR 5.71, 95% confidence interval [CI] 1.12–26.93, p=0.018), congestive heart failure (OR 2.2, 95% CI 1.16–4.00, p=0.010), chronic pulmonary disease (OR 1.76; 95% CI 1.09–2.78, p=0.015), and diabetes (OR 1.66; 95% CI 1.08–2.52, p=0.019) were associated with PJI from antibiotic resistant organisms. However, there was no difference in the rate of PJI between cefazolin and vancomycin monotherapy when stratified for the aforementioned comorbidities. The present study reveals that comorbidities do not significantly alter the organism profile of high-risk comorbidities and that comorbidities associated with immune deficits do not influence the rate of PJI between two different antibiotics. The results of this study thus support current guidelines, which provide a universal recommendation rather than a protocol that is tailored to a patient's preexisting comorbidities.
Failure of a two-stage exchange arthroplasty for management of periprosthetic joint infection (PJI) poses a major clinical challenge. There is a paucity of information regarding the outcome of further surgical intervention in these patients. Thus, we aim to report the clinical outcomes of subsequent surgical intervention following a failed prior two-stage exchange. Our institutional database was used to identify 60 patients (42 knees and 18 hips) with a failed prior two-stage exchange from infection, who underwent further surgical intervention between 1998 and 2012 and had a minimum of two years follow-up. A retrospective review was performed to extract relevant clinical information, such as mortality, microbiology, and subsequent surgeries. Musculoskeletal Infection Society criteria were used to define PJI, and treatment success was defined using the Delphi criteria as previously reported. Irrigation and debridement (I&D) was performed after a failed two-stage exchange in 61.7% (37/60) patients. The failure rate of I&D in this cohort was 51.3% (19/37). Two patients underwent amputation after I&D due to uncontrolled infection. A total of 40 patients underwent an intended a second two-stage exchange. Reimplantation occurred in only 65% of cases (26/40), and infection was controlled in 61.6% (16/26) of patients. An interim spacer exchange was required in 15% (6/40) of the cases. Of the 14 cases that did not undergo a second stage reimplantation, 5 required amputation, 6 had retained spacers, 1 underwent arthrodesis, and 2 patients died. Further surgical intervention after a failed prior two-stage exchange has poor outcomes. I&D has a high failure rate and many of the patients who are deemed candidates for a second two-stage exchange either do not undergo reimplantation for various reasons or fail after reimplantation. The management of PJI clearly remains imperfect, and there is a dire need for further innovations that may improve the care of these PJI patients.
The aim of this study was to evaluate the feasibility
of using the intact S1 nerve root as a donor nerve to repair an avulsion
of the contralateral lumbosacral plexus. Two cohorts of patients
were recruited. In cohort 1, the L4–S4 nerve roots of 15 patients
with a unilateral fracture of the sacrum and sacral nerve injury
were stimulated during surgery to establish the precise functional
distribution of the S1 nerve root and its proportional contribution
to individual muscles. In cohort 2, the contralateral uninjured
S1 nerve root of six patients with a unilateral lumbosacral plexus
avulsion was transected extradurally and used with a 25 cm segment
of the common peroneal nerve from the injured leg to reconstruct
the avulsed plexus. The results from cohort 1 showed that the innervation of S1 in
each muscle can be compensated for by L4, L5, S2 and S3. Numbness
in the toes and a reduction in strength were found after surgery
in cohort 2, but these symptoms gradually disappeared and strength
recovered. The results of electrophysiological studies of the donor
limb were generally normal. Severing the S1 nerve root does not appear to damage the healthy
limb as far as clinical assessment and electrophysiological testing
can determine. Consequently, the S1 nerve can be considered to be
a suitable donor nerve for reconstruction of an avulsed contralateral
lumbosacral plexus. Cite this article:
To examine patient mortality, implant survivorship, and complication profiles of proximal femoral replacement (PFR) as compared to revision total hip arthroplasty (REV) or open reduction internal fixation (ORIF) in the treatment of acute periprosthetic fractures of the proximal femur. We performed a retrospective controlled chart review at our tertiary center from from 2000–2010, identifying 97 consecutive acute periprosthetic proximal femoral fractures. Patients were stratified into three treatment groups: PFR (n=21), REV (n=19), and ORIF (n=57). Primary outcome measures included death, implant failure, and reoperation. We also recorded patient demographics, medical comorbidities, fracture type, treatment duration, time to treatment, and complication profiles. Statistical analyis included competing risks survival, which allows independent survival analysis of competing failure mechanisms such as death and implant failure.Objectives
Methods
