Aims. Periprosthetic fungal infections are rare and account for 1–2% of all periprosthetic joint infections (PJI). This study aims at presenting treatment details, clinical and microbiological results in a large single centre cohort. Methods. We retrospectively identified 29 patients (9 total knee replacements (TKA) and 20 total hip replacements (THA) treated for a fungal infection between 2007 and 2019. Microbiological findings, patient demographics and complications were analysed. Statistical analysis was performed using descriptive statistics; non-parametric analysis were performed using the Mann-Whitney U-Test. Infection-free survival was determined using Kaplan-Meier analysis and differences in survival were analysed using the log-rank test. The p value was set at p<0.05 with 95% confidence intervals (95% CI) provided. Results. 28% (8/29) suffered from reinfection. The reinfection-free survival probability was 65% (95% CI 45–85) after a median follow- up period of 28 months (IQR 6 – 39). With the numbers we had, we were not able to detect a difference between THA and TKA re-infections (p=0.517). Four patients underwent amputation, 3 patients had a definitive girdlestone hip and eight patients died after a median of 5 months after first-stage surgery (IQR 1–7). All patients treated had positive synovial fluid or tissue cultures for Candida species. In 22 /29 patients C. albicans, in 3 patients C. parapsilosis, in 2 patients C. glabrata and in 1 patient each C. famata, C. dubliniensis and C. gulliermondii. Polymicrobial bacterial infection was found in 86% of patients with staphylococci in 20 patients, E. coli in 2 patients, vancomycin-resistant enterococci, pseudomonas, acinetobacter and achromobacter species in 1 patient each. When investigating risk factors for reinfection, with the numbers we had we were not able to find a significant difference for patients with polymicrobial infection (p=0.974), azole-resistant Candida (p=0.491), tobacco users (p=0.175), or diabetics (p=0.54). Furthermore, median age (73 vs. 72, p=0.756) and Charlson comorbidity score (6 (interquartile range (IQR) 4–8) vs. 8 (IQR 5–10), p=0.184) were not different between the groups while on the other hand there was a trend for a higher body mass index in patients with reinfection (34 (IQR 31–38) vs. 28 (IQR 25–33), p=0.075). Conclusions. Fungal PJI is associated with poor reinfection free survival, frequent revisions, and high mortality. All infections were caused by Candida spp. in which azole-resistance most be considered when planning treatment. While polymicrobial infection complicated treatment there was no difference in survival. A higher BMI and comorbidity score might be associated with higher risk for reinfections

Aim. To describe the risk factors, microbiology and treatment outcome polymicrobial prosthetic joint infections (PJI) compared to monomicrobial PJI. Methods. Between January 2011 and December 2021, a total of 536 patients were diagnosed with PJI at our institution. Clinical records were revised, and 91(16.9%) had an isolation of two or more pathogens. Age, sex, previous conditions, Charlson comorbidity score, previous surgery, PJI diagnosis and surgical and antibiotic treatment, from the index surgery onwards were reviewed and compared between groups. Results. Polymicrobial PJI success rate was 57.1%, compared to 85.3% of the monomicrobial PJI(p=0.0036). There were no statistically significative differences between acute and chronic infections. In terms of related risk factors, revision surgery(p=0.0002), fracture(p=0.002), tobacco(p=0.0031) and Body Mass Index (BMI) between 20–25(p=0.0021) were associated to monomicrobial PJI, whereas overweight(p=0.005) and obesity(p=0.02) were linked to polymicrobial PJI. Regarding pathogens, the most common microorganism isolated in monomicrobial was S.aureus (33.5%), followed by S. epidermidis(20%) and gram negative bacilli (12.2%); while S. epidermidis(56%), gram negative bacilli (41.8%) and E.colli (30.8%) were the most frequent in the polymicrobial PJI. Enterococci(p=0.0008), S. epidermidis(p=0.007), E.colli (p=0.0008), gram negative bacilli (p=0.00003) and atypical bacteria (p=0.00001) statistically significative linked to polymicrobial PJI; while S.aureus (p=0.018) was related to monomicrobial PJI. Conclusion. Polymicrobial PJI showed worse outcome compared to monomicrobial PJI in our cohort. In terms of risk factors, overweight, obesity and some pathogens like gram negative bacilli, atypical bacteria, enterococci, S. epidermidis and E.colli were associated with Polymicrobial PJI

Aim. To describe the impact of a failed DAIR in the further prognosis of the prosthesis after a PJI. Method. A retrospective multicentrically study was conducted, including 10 institutions from all over the country. PJI-confirmed patients who underwent DAIR clinical records were revised. Age, sex, relevant previous conditions, Charlson comorbidity score, previous surgery, PJI diagnosis and surgical and antibiotic treatment, from the index surgery onwards. DAIR failure was defined as the removal of the prosthesis and/or an antibiotic suppressive treatment. Results. 95 failed DAIR were identified, 43 of whom were treated with another DAIR (70% success rate), 20 with one-stage revision (75% success rate) and 25 with two-stage revision (92% success rate). As risk factors for the failure of a second DAIR, a non-specialized surgical team(p=.0034), mobile components exchange(p=.009) and polymicrobial infections(p=.03) were identified. Regarding to one-stage revisions, no risk factors were identified, and regarding to two-stage revisions, polymicrobial infection were identified (p=.028). Conclusions. A second DAIR could sabe up to 70% of the prosthesis in our series. Furthermore, the outcome of the subsequent one or two-stage revision does not seem to be affected bay the previous failed DAIR. In terms of risk factors of failure, non-specialized surgical team, no mobile components exchange, and polymicrobial infections were identified for the DAIR, and polymicrobial infections for the two-stage revisions

Background. The advent of value-based conscientiousness and rapid-recovery discharge pathways presents surgeons, hospitals, and payers with the challenge of providing the same total hip arthroplasty episode of care in the safest and most economic fashion for the same fee, despite patient differences. Various predictive analytic techniques have been applied to medical risk models, such as sepsis risk scores, but none have been applied or validated to the elective primary total hip arthroplasty (THA) setting for key payment-based metrics. The objective of this study was to develop and validate a predictive machine learning model using preoperative patient demographics for length of stay (LOS) after primary THA as the first step in identifying a patient-specific payment model (PSPM). Methods. Using 229,945 patients undergoing primary THA for osteoarthritis from an administrative database between 2009– 16, we created a naïve Bayesian model to forecast LOS after primary THA using a 3:2 split in which 60% of the available patient data “built” the algorithm and the remaining 40% of patients were used for “testing.” This process was iterated five times for algorithm refinement, and model performance was determined using the area under the receiver operating characteristic curve (AUC), percent accuracy, and positive predictive value. LOS was either grouped as 1–5 days or greater than 5 days. Results. The machine learning model algorithm required age, race, gender, and two comorbidity scores (“risk of illness” and “risk of morbidity”) to demonstrate excellent validity, reliability, and responsiveness with an AUC of 0.87 after five iterations. Hospital stays of greater than 5 days for THA were most associated with increased risk of illness and risk of comorbidity scores during admission compared to 1–5 days of stay. Conclusions. Our machine learning model derived from administrative big data demonstrated excellent validity, reliability, and responsiveness after primary THA while accurately predicting LOS and identifying two comorbidity scores as key value-based metrics. Predictive data has the potential to engender a risk-based PSPM prior to primary THA and other elective orthopaedic procedures

Aims. The primary aim was to assess whether preoperative health-related quality of life (HRQoL) was associated with postoperative mortality following total hip arthroplasty (THA) and knee arthroplasty (KA). Secondary aims were to assess whether patient demographics/comorbidities and/or joint-specific function were associated with postoperative mortality. Methods. Patients undergoing THA (n = 717) and KA (n = 742) during a one-year period were identified retrospectively from an arthroplasty register. Patient demographics, comorbidities, Oxford score, and EuroQol five-dimension (EQ-5D) were recorded preoperatively. Patients were followed up for a minimum of seven years and their mortality status was obtained. Cox regression analysis was used to adjust for confounding. Results. During the study period, 111 patients (15.5%) undergoing THA and 135 patients (18.2%) undergoing KA had died at a mean follow-up of 7.5 years (7 to 8). When adjusting for confounding, the preoperative EQ-5D was associated with postoperative mortality, and for each 0.1 difference in the utility there was an associated change in mortality risk of 6.7% (p = 0.048) after THA, and 6.8% (p = 0.047) after KA. Comorbidities of connective tissue disease (p ≤ 0.026) and diabetes (p ≤ 0.028) were associated with mortality after THA, whereas MI (p ≤ 0.041), diabetes (p ≤ 0.009), and pain in other joints (p ≤ 0.050) were associated with mortality following KA. The preoperative Oxford score was associated with mortality, and for each one-point change in the score there was an associated change in mortality risk of 2.7% (p = 0.025) after THA and 4.3% (p = 0.003) after KA. Conclusion. Worse preoperative HRQoL and joint specific function were associated with an increased risk of postoperative mortality. Both HRQoL and joint-specific function decline with longer waiting times to surgery for THA and KA and therefore may result in an increased postoperative mortality risk than would have been expected if surgery had been undertaken earlier. Cite this article: Bone Jt Open 2022;3(12):933–940

We compared revision and mortality rates of 4668 patients undergoing primary total hip and knee replacement between 1989 and 2007 at a University Hospital in New Zealand. The mean age at the time of surgery was 69 years (16 to 100). A total of 1175 patients (25%) had died at follow-up at a mean of ten years post-operatively. The mean age of those who died within ten years of surgery was 74.4 years (29 to 97) at time of surgery. No change in comorbidity score or age of the patients receiving joint replacement was noted during the study period. No association of revision or death could be proven with higher comorbidity scoring, grade of surgeon, or patient gender. We found that patients younger than 50 years at the time of surgery have a greater chance of requiring a revision than of dying, those around 58 years of age have a 50:50 chance of needing a revision, and in those older than 62 years the prosthesis will normally outlast the patient. Patients over 77 years old have a greater than 90% chance of dying than requiring a revision whereas those around 47 years are on average twice as likely to require a revision than die. This information can be used to rationalise the need for long-term surveillance and during the informed consent process

Background: A general increase in total number of primary total hip arthroplasty (THA) has been observed in Denmark from 3.828 in 1995 to 7.645 in 2006. During the same period the number of pa-tients treated at private clinics has also increased. To our knowledge no studies, comparing patient characteristics and treatment quality between public and private hospitals, have been published. We compared patients’ characteristics and outcome following THA in private and public hos-pitals. Materials and Methods: We used data from the Danish Hip Arthroplasty Registry to identify 69 249 primary THA’ies performed between 1 January 1995 to 31 December 2006. To detect eventual difference in patient characteristics- age, gender, diagnosis leading to THA, Carlson’s comorbidity score and Charnley category were evaluated. We matched 3 658 cases operated in private with 3 658 controllers operated in public hospitals on propensity score. Scoring parameters were age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis. We used multivariate logistic regression on propensity score matched data to assess association between type of hospital and outcome by computing relative risks and 95% Confidence Interval (CI). Outcomes were perioperative complications, readmission within 3 months, re-operation within 2 years, implant failure after 5 years, and mortality within 3 months of surgery. Results: Private hospitals operated on older females, patients with primary osteoarthritis and low comorbidity and Charnley category 1. Patients in private and propensity matched controls from public hospitals showed no differences in age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis (p-value < 0,0001). Based on matched data, private hospitals had lower relative risk for perioperative complications (0.39, 0.26–0.60), reoperations (0.59, 0.41–0.83) and readmissions (0.57, 0.42–0.77) compared with public. There was no difference in mortality or implant failure. Discussion and Conclusions: We had no data on surgeon, general health and socioeconomic status of the patients. In addition, reported data from private clinics have not been validated in contrast to public hospitals. We found significant difference between patient characteristics operated at public versus private hospitals. No difference was evident regarding mortality and implant failure but for complications, reoperations and readmissions between private and public hospitals

Hip fractures in young adults are rare but represent an important cohort of patients, of which relatively limited data exists. The aim of this study was to evaluate this distinct subgroup of hip fractures from an epidemiological perspective and assess their subsequent outcomes. Patients aged 18–50 were identified across an 8 year period from a total of 5326 hip fractures. 46 hip fractures met the inclusion criteria and a retrospective case series analysis was conducted. 25/46 (54%) of fractures were intracapsular and 21/46 (46%) were extracapsular. Only 15/46 (33%) of fractures were sustained from a high energy mechanism and 31/46 (67%) low energy. The low energy cohort was significantly more comorbid with a mean Elixhauser comorbidity score of 1.5 compared to the high energy cohort 0.3 (p<0.0005, unpaired t-test). Alcohol excess was the most prevalent comorbidity present in 24% of patients and was a positive predictor in complication (p=0.006, binary regression). Failure of fixation (non-union/avascular necrosis) in displaced intracapsular fractures sustained following low energy trauma managed by internal fixation 5/11 (45%) was markedly higher than the high energy cohort 0/6 (0%). 5 year mortality was 9% for all hip fractures, six times higher than an aged matched cohort of non-hip fractures (p=0.007, Wilcoxon test). Representing only 0.86% of all hip fractures in the study period, hip fractures in young adults are rare. A clear sub-division of patients is observed between patients with a low and high energy mechanism, both in terms of level of comorbidity and surgical outcome

Patient satisfaction is not uniform or consistent following revision total knee arthroplasty. This study evaluates ninety-nine patients with a self-administered patient satisfaction questionnaire at a minimum of two years following the revision procedure (1997–99) to determine differences between satisfied (sixty-six patients) and dissatisfied patients (thirty-three patients). Univariate analysis revealed that patients satisfied with their results were significantly different (p< .05) than dissatisfied patients with regards to post op scores including those of the WOMAC pain and function, oxford, and SF-12. Patients were not different with regards to (p> .05) age, comorbidity score, surgical approach, or sepsis as a reason for the revision procedure. Regression analysis demonstrated that gender, post-op WOMAC score, and pre-op arc of motion were significant determinants of satisfaction. The purpose of this study is to evaluate determinants of patient satisfaction following revision total knee arthroplasty. Patient satisfaction with revision knee surgery is most strongly associated with both pre and post-operative descriptors of knee function as well as gender. Understanding the variables associated with satisfaction/dissatisfaction following revision knee arthroplasty may further assist ongoing research efforts to improve the outcomes of this procedure. Univariate analysis revealed that patients satisfied with their results were significantly different (p< .05) than dissatisfied patients with regards to WOMAC pain and function score, oxford knee score, and SF-12. Patients were not different with regards to (p> .05) age, comorbidity score, surgical approach, or presence of sepsis as a reason for the revision procedure. Regression analysis demonstrated that gender, post-op WOMAC score, and pre-op arc of motion were significant determinants of satisfaction (p< .05). A self-administered patient satisfaction survey was completed by ninety-nine patients at a minimum of two years following revision total knee arthroplasty. Fifty-nine patients were females and forty were males. Sixty-six patients were satisfied and thirty-three patients were dissatisfied with the outcome of their surgery at two years post-op. Univariate analysis and multivariate regression suggest that pre and post-operative joint function and gender are the most significant determinants of patient satisfaction

Introduction. Recent studies of novel healthcare episode payment models, such as the Bundled Payments for Care Improvement (BPCI) initiative, have demonstrated pathways for improving value. However, these models may not provide appropriate payments for patients with significant medical comorbidities or complications. The objective of this study was to identify risk factors for exceeding our institution's target payment, the so-called “bundle busters.”. Methods. After receiving an exemption from the Institutional Review Board, we queried our institutional data warehouse for all patients (n=412) that underwent total joint arthroplasty (TJA) of the hip (n=192), knee (n=207), or ankle (n=13), and qualified for our institution's bundled payments model during the study time period (July 2015 – May 2017). Patients with medical conditions that were not well controlled or were potentially optimizable were all sent for preoperative medical optimization prior to surgery. For each 90-day episode, patient characteristics, medical comorbidities, perioperative data, and payments from the Centers for Medicare and Medicaid Services (CMS) were obtained. Episodes where Medicare payments exceeded the target payment were considered “busters”. The busters were older, and had higher comorbidity scores (all, p<0.01). Variables were summarized using descriptive statistics and risk ratios were calculated using a modified Poisson regression analysis. Results. Of the 412 patients, 123 were bundle busters (30%). There was a median institutional loss of $11,797 (IQR, $4,312 – $26,771) for the bundle busters and a median gain of $7,402 ($5,657 – $9,206) for the non-busters. Of the 32 risk factors evaluated, 11 were identified as Independent risk factors for busting the bundle (all, p<0.05). Nine of the 11 (82%) are non-modifiable risk factors and include age, disease specific diagnoses (fracture and avascular necrosis), and medical comorbidities (congestive heart failure, pulmonary circulation disorders, renal disease, cardiac arrhythmia, chronic pulmonary disease, and neurological disorder). The remaining two medical comorbidities are potentially modifiable and include diabetes with complications, and preoperative anemia. Conclusion. Though modifiable risk factors should continue to be optimized prior to TJA, as they were in this population, there are still many non-modifiable preoperative risk factors that can lead to costs exceeding the BPCI established institutional payment goal. As such, further work with payors may be needed to help fairly and appropriately consider these non-modifiable factors which result in increased costs

Aim. The optimal treatment of streptococcal prosthetic joint infections (PJIs) is unclear. Poorer outcome has been associated with Streptococcus agalactiae species, comorbidities and polyethylene exchange for conservative approach. Rifampicin use may be associated with higher remission rate but results are sparse. Method. A cohort of streptococcal PJI (including total hip arthroplasty –THA- or total knee arthroplasty –TKA-) was prospectively created and retrospectively reviewed in 7 reference centers for management of complex PJI between January 1, 2010 and December 31, 2012. Results. Seventy patients (47 infections of THA and 23 infections of total TKA) with monomicrobial infections were included. Median age was 77 (interquartile range [IQR] [69 – 83], 15.6% (n=11) had diabetes, median Charlson comorbidity score was 4 [3 – 6] and 31.4% (n=22) had chronic heart failure. Streptococcus agalactiae and S. dysgalactiae were the most commonly streptococcal species found, in 38.6% (n=27) and 17.1% (n=12) of cases respectively. Debridement, antibiotic and implant retention (DAIR) was performed after a median time of 7 days [3 – 8] with polyethylene exchange (PE) performed in 21% of these treatments. After a median follow-up of 22 month [12 – 31], 27% of patients relapsed corresponding to 51.4% of DAIR treatment and 0% of one- (n=15) or two-stage exchange strategy (n=17). Rifampicin or levofloxacin combination were not associated with a better outcome (p=0.82 and p=1, respectively). A shorter intravenous antimicrobial therapy, a S. agalactiae species and DAIR treatment were associated with a higher risk of failure. In multivariate analysis, only DAIR treatment and S. agalactiae were independent factors of relapse. PE was associated with a trend toward benefit (odds ratio 0.26 [95% CI: 0.021 – 1.98; p=0.26]) but did not reach statistical significance. Conclusions. Streptococcal PJIs managed with DAIR have a poor prognosis and S. agalactiae seems to be an independent factor of failure

Aims

To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA).

Aims

When a total ankle arthroplasty (TAA) fails, it can be converted to a fusion or a revision arthroplasty. Despite the increasing numbers of TAAs being undertaken, there is little information in the literature about the management of patients undergoing fusion following a failed TAA. The primary aim of this study was to analyze the survival of fusions following a failed TAA using a large dataset from the National Joint Registry (NJR).

The February 2023 Knee Roundup³⁶⁰ looks at: Machine-learning models: are all complications predictable?; Positive cultures can be safely ignored in revision arthroplasty patients that do not meet the 2018 International Consensus Meeting Criteria; Spinal versus general anaesthesia in contemporary primary total knee arthroplasty; Preoperative pain and early arthritis are associated with poor outcomes in total knee arthroplasty; Risk factors for infection and revision surgery following patellar tendon and quadriceps tendon repairs; Supervised versus unsupervised rehabilitation following total knee arthroplasty; Kinematic alignment has similar outcomes to mechanical alignment: a systematic review and meta-analysis; Lifetime risk of revision after knee arthroplasty influenced by age, sex, and indication; Risk factors for knee osteoarthritis after traumatic knee injury.

Aims

The number of revision total ankle arthroplasties (TAAs) which are undertaken is increasing. Few studies have reported the survival after this procedure. The primary aim of this study was to analyze the survival of revision ankle arthroplasties using large datasets. Secondary aims were to summarize the demographics of the patients, the indications for revision TAA, further operations, and predictors of survival.

Aims

Periprosthetic joint infection (PJI) in total hip arthroplasty in the elderly may occur but has been subject to limited investigation. This study analyzed infection characteristics, surgical outcomes, and perioperative complications of octogenarians undergoing treatment for PJI in a single university-based institution.

Aims

In cases of severe periprosthetic joint infection (PJI) of the knee, salvage procedures such as knee arthrodesis (KA) or above-knee amputation (AKA) must be considered. As both treatments result in limitations in quality of life (QoL), we aimed to compare outcomes and factors influencing complication rates, mortality, and mobility.

Aims

The aim of this study was to assess factors associated with the estimated lifetime risk of revision surgery after primary knee arthroplasty (KA).

Gordon M, Stark A, Sköldenberg OG, Kärrholm J, Garellick G. The influence of comorbidity scores on re-operations following primary total hip replacement: Comparison and validation of three comorbidity measures. Bone Joint J 2013;95-B:1184-1191