BACKGROUND: Surgical site infection (SSI) is an important cause of disease burden and healthcare costs. Fully manual surveillance is time-consuming and prone to subjectivity and inter-individual variability, which can be partly overcome by semi-automated surveillance. Algorithms used in orthopaedic SSI semi-automated surveillance have reported high sensitivity and important workload reduction. This study aimed to design and validate different algorithms to identify patients at high risk of SSI after hip or knee arthroplasty.
METHODS: Retrospective data from manual SSI surveillance between May 2015 and December 2017 were used as gold standard for validation. Knee and hip arthroplasty were included, patients were followed up for 90 days and European Centre for Disease Prevention and Control SSI classification was applied. Electronic health records data was used to generate different algorithms, considering combinations of the following variables: ≥1 positive culture, ≥ 3 microbiological requests, antimicrobial therapy ≥ 7 days, length of hospital stay ≥ 14 days, orthopaedics readmission, orthopaedics surgery and emergency department attendance. Sensitivity, specificity, negative and predictive value, and workload reduction were calculated.
RESULTS: In total 1631 surgical procedures were included, of which 67.5% (n = 1101) in women; patients\' median age was 69 years (IQR 62 to 77) and median Charlson index 2 (IQR 1 to 3). Most surgeries were elective (92.5%; n = 1508) and half were hip arthroplasty (52.8%; n = 861). SSI incidence was 3.8% (n = 62), of which 64.5% were deep or organ/space infections. Positive culture was the single variable with highest sensitivity (64.5%), followed by orthopaedic reintervention (59.7%). Twenty-four algorithms presented 90.3% sensitivity for all SSI types and 100% for deep and organ/space SSI. Workload reduction ranged from 59.7 to 67.7%. The algorithm including ≥ 3 microbiological requests, length of hospital stay ≥ 14 days and emergency department attendance, was one of the best options in terms of sensitivity, workload reduction and feasibility for implementation.
CONCLUSIONS: Different algorithms with high sensitivity to detect all types of SSI can be used in real life, tailored to clinical practice and data availability. Emergency department attendance can be an important variable to identify superficial SSI in semi-automated surveillance.

OBJECTIVE: Establishing the diagnosis of loosening in total or unicondylar knee arthroplasty remains a challenge with different clinical and radiological signs evaluated in study designs with high risk of bias, where few or incomplete criteria are formulated for establishing the diagnosis of implant loosening. This study aimed at evaluating the variability between different clinical and radiological criteria and establish a consensus regarding clinical and radiological criteria for the diagnosis of knee arthroplasty loosening.
METHODS: Highly specialized knee surgeons focusing on revision arthroplasty were invited to take part in an international panel for a Delphi consensus study. In the first round, the participants were asked to state their most important clinical and radiological criteria for implant loosening. In a second round, the panel\'s agreement with the collected criteria was rated on a 5-point Likert scale (1-5). High variability was defined by receiving at least one score each indicating complete disagreement and complete agreement. Consensus was established when over 70% of participants rated a criterion as \'fully agree\' (5) or \'mostly agree\' (4).
RESULTS: High variability was observed in 56% of clinical criteria and 38% of radiological criteria. A consensus was reached on one clinical (weight-bearing pain [82%]) and four radiological criteria, that is, implant migration, progressive radiolucencies, subsidence and radiolucencies >2 mm on X-ray or computed tomography (CT) (84%-100%).
CONCLUSIONS: Amongst specialized knee revision surgeons, there is high variability in clinical and radiological criteria that are seen as important contributing factors to diagnosis of knee implant loosening. A consensus was reached on weight-bearing pain as clinical criterion and on implant migration, progressive radiolucencies, subsidence and radiolucencies of more than 2 mm on X-ray or CT as radiological criteria. The variability rates observed, along with the criteria that reached consensus, offer important insights for the standardization of diagnostic protocols.
METHODS: Level V.

OBJECTIVE: This study aimed (1) to determine complications and survival rates of lateral opening wedge distal femoral osteotomy (LOW-DFO) in the long term, (2) to assess their clinical outcomes in the long term and (3) to identify risk factors of failure.
METHODS: Between 1991 and 2011, 62 LOW-DFOs were performed in the same department. Inclusion criteria were all isolated LOW-DFO performed for isolated lateral tibiofemoral osteoarthritis and valgus malalignment, with a minimum 10-year follow-up. Thirty-eight patients were included, with a mean age of 48 ± 9 years. All patients had clinical and radiological assessments. The survival curves were calculated based on the following endpoints: unicompartmental or total knee arthroplasty.
RESULTS: The mean follow-up was 15.2 ± 4.4 [10-29] years. The mean preoperative mechanical FemoroTibial Axis (mFTA) was 188.8° ± 3.2° [184°-197°], primarily due to femur deformity (mean lateral distal femoral axis [LDFA] 83.2° ± 2.8°). Bone union was achieved in 89.5% of patients (n = 34) at a mean delay of 6.5 ± 6.7 months. The complication rate was 26% (five stiffness, one nonunion, three secondary displacements and one deep vein thrombosis). Nine revision surgeries (24%) were recorded. Survival rates at 5 and 10 years were 92.1% and 78.9%, respectively. The mean delay between DFO and total knee arthroplasty (TKA) was 11.6 ± 5.7 [1-27] years. Nineteen patients (50%) were free of TKA at the last follow-up. KSS scores were improved significantly. Return to sports was obtained in 92% of cases (n = 35), with a mean delay of 11 ± 8 months. Seventy-four per cent of patients were satisfied or very satisfied with the surgery. Eighty-four per cent would be willing to undergo the surgery again. Older age (p = 0.032) was a significant risk factor for TKA conversion.
CONCLUSIONS: LOW-DFO is an efficient procedure to manage lateral knee osteoarthritis in young patients with valgus deformity, with a good survival rate at 10 years and high patient satisfaction.
METHODS: Level III.

UNASSIGNED: While unicompartmental knee arthroplasty (UKA) and osteotomy procedures are commonly used to treat knee osteoarthritis, the differences in complication profiles between procedures are still poorly understood.
UNASSIGNED: The purpose of this study was to assess the trends and complication rates of UKA and periarticular knee osteotomy for knee osteoarthritis among newly trained surgeons by using the American Board of Orthopaedic Surgery (ABOS) Part II Oral Examination Case List database. It was hypothesized that more adult reconstruction fellowship-trained surgeons would perform UKA, while more sports medicine fellowship-trained surgeons would perform osteotomy, and that both procedures would have low rates of complications.
UNASSIGNED: Cross-sectional study; Level of evidence, 3.
UNASSIGNED: The ABOS database was queried for patients who underwent UKA, high tibial osteotomy, and distal femoral osteotomy procedures in examination years 2011 to 2021. Patient characteristics, surgeon fellowship training history, surgeon-reported postoperative complications, and readmission and reoperation rates were recorded. Comparisons between the UKA and osteotomy groups were performed using independent t tests and chi-square tests.
UNASSIGNED: There were 2524 patients in the UKA group and 270 patients in the osteotomy group. The majority of newly trained surgeons performing UKA (70.5%) had fellowship training in adult reconstruction, while the majority of those performing osteotomy (57.8%) had fellowship training in sports medicine (P < .001). The incidence of UKA and osteotomy increased during the study period (18.8 UKAs and 1.8 osteotomies performed per 10,000 cases in 2011 vs 39.5 UKAs and 4.2 osteotomies performed per 10,000 cases in 2021). Rates were significantly higher for osteotomy compared with UKA regarding anesthetic complications (2.2% vs 0.6%; P = .015), surgical complications (23.7% vs 7.3%; P < .001), reoperation (5.2% vs 1.9%; P = .002), and infection (6.7% vs 1.4%; P < .001). There were no significant differences in rates of medical complication, readmission, deep vein thrombosis, pulmonary embolism, or stiffness/arthrofibrosis.
UNASSIGNED: Among newly trained surgeons taking the ABOS Part II Oral Examination, the incidence of UKA and periarticular knee osteotomy increased over the past decade. Compared with UKA, complication rates were higher after osteotomy, with an overall surgical complication rate of 23.7%.

Introduction This study aims to investigate the complex decision-making process of patients in India when choosing surgeons for joint replacement surgery, with a focus on both clinical and non-clinical factors influencing their preferences. Methods This was a cross-sectional observational study conducted at the KIMS-Sunshine Hospitals, Hyderabad, a high-volume tertiary care institute in India, in which patients with end-stage osteoarthritis requiring primary total knee arthroplasty were evaluated using a self-administered questionnaire, which assessed both patient-related and surgeon-related factors in choosing their joint replacement surgeon. Results A total of 210 participants were surveyed among whom the majority were females with an average age of 60.2 years with the majority belonging to the upper-middle-class socioeconomic status (48.6%, N=102). Fifty-nine percent preferred surgeons with over 20 years of experience, and 63.8% were willing to travel out-of-state for recognized expertise. Family recommendations (33.8%) and surgeon reputation (24.3%) were primary factors in surgeon selection. A vast majority (73.3%) preferred surgeons who were skilled in robotic surgery and had foreign training (32.9%). However, the majority (67.6%) did not express any gender preference. The survey highlighted a broad range of informational sources affecting decisions, including financial consideration (63.8%), personal referrals, and online platforms (17.1%). Preferences were also shaped by hospital reputation and insurance options (10.5%), illustrating a nuanced interplay of quality, cost, and personal connections in the selection process. Conclusion The findings of this survey illuminate the intricate and diverse preferences exhibited by patients when selecting a surgeon for joint replacement surgery. A significant rise in patient expectations is evident, underscoring a demand for more personalized, contemporary, and high-quality healthcare services. Importantly, geographical proximity appears to be a diminishing concern in their decision-making process. This trend presents an opportunity for centers of excellence to extend their influence and attract patients on both a regional and national level.

UNASSIGNED: The objective of the research was to carry out a comparative study between Smith & Nephew ® or Zimmer ® prostheses with thick versus thin polyethylene, in patients undergoing primary total knee arthroplasty, during a short-term follow-up. Thus, the objective was to analyze the survival of the implants in question under the clinical and radiographic aspect.
UNASSIGNED: The sample was divided into two groups: Group 1 with thick polyethylene and group 2 with thin polyethylene. A clinical analysis of the patients was carried out and the implants were checked for loosening.
UNASSIGNED: The groups were similar when compared. According to the Ahlbäck classification, 83% of the patients were in groups IV and V. The median functional score in the postoperative period was similar between the two groups. Postoperatively, the tibiofemoral angle fluctuated between 5 and 6 0 valgus on average. Two complications were observed in each group. None of the evaluated patients presented implant loosening.
UNASSIGNED: Patients treated with thick polyethylene had the same functional score as the control group, as well as the absence of radiographic changes in this short-term follow-up, with implant survival and a similar rate of complications between both groups. Level of evidence III, Retrospective study.
UNASSIGNED: O objetivo desta pesquisa foi realizar um estudo comparativo entre as próteses Smith & Nephew ® e Zimmer ®, com polietileno espesso versus o fino, em pacientes submetidos à artroplastia total primária do joelho, durante um seguimento de curto prazo. Dessa forma, foi analisada a sobrevida dos implantes em questão sob o aspecto clínico e radiográfico.
UNASSIGNED: A amostra foi dividida em dois grupos: grupo 1 com polietileno espesso e grupo 2 com polietileno fino. Foi realizada análise clínica dos pacientes e verificado se ocorreu soltura dos implantes.
UNASSIGNED: Os grupos tiveram resultados semelhantes quando comparados. Segundo a classificação de Ahlbäck, 83% dos pacientes eram dos grupos IV e V. A mediana do escore funcional no pós-operatório foi similar entre os grupos. No pós-operatório o ângulo tíbio-femoral oscilou na média entre 5 e 6 0 de valgo. Foram observadas duas complicações em cada grupo. Nenhum dos pacientes avaliados apresentou soltura do implante.
UNASSIGNED: Os pacientes tratados com o polietileno espesso apresentaram o mesmo escore funcional do grupo controle, assim como ausência de alterações radiográficas nesse seguimento de curto prazo, com sobrevida do implante e índice de complicações similar entre ambos os grupos. Nível de evidência III, Estudo retrospectivo.

BACKGROUND: Knee arthroplasty is a well-established surgery with good clinical outcomes. However, periprosthetic fractures and aseptic loosening negatively impact clinical outcomes, and osteoporosis is one of the causes of such complication. Osteoporosis is usually evaluated by bone mineral density of the lumbar spine and hip using dual-energy X-ray absorptiometry (DXA). However, the prevalence of this disease in patients with knee osteoarthritis scheduled for knee arthroplasty may be underestimated due to differences in the measurement sites. This study aimed to determine the appropriate measurement site for DXA that would not miss osteoporosis in female patients with knee osteoarthritis undergoing knee arthroplasty.
METHODS: We measured bone mineral density preoperatively in the consecutive 50 female patients with knee osteoarthritis scheduled for knee arthroplasty by dual-energy X-ray absorptiometry at five sites: the lumbar spine, bilateral-total hip, and femoral neck. We then compared the prevalence of osteoporosis among the four combinations of the lumbar spine and single hip site (ipsilateral or contralateral total hip or femoral neck).
RESULTS: Osteoporosis prevalence in the combination of the lumbar spine and ipsilateral or contralateral total hip was 32%, and that in the combination of the lumbar spine and contralateral femoral neck was 44%. Notably, the disease\'s prevalence in the combination of the lumbar spine and ipsilateral femoral neck was 50%, which was significantly higher than that in the other combinations.
CONCLUSIONS: Osteoporosis should be evaluated by bone mineral density in the combination of the lumbar spine and ipsilateral femoral neck in female patients with knee osteoarthritis scheduled for knee arthroplasty.

Pain catastrophizing is an exaggerated focus on pain sensations. It may be an independent factor influencing pain and functional outcomes of knee arthroplasty. We aimed to evaluate the association between pre-operative pain catastrophizing with pain and function outcomes up to one year after knee arthroplasty. We used data from a cohort study of patients undergoing primary knee arthroplasty (either total or unicompartmental arthroplasty) for knee osteoarthritis. Pain catastrophizing was assessed pre-operatively using the Pain Catastrophizing scale (PCS). Other baseline variables included demographics, body mass index, radiographic severity, anxiety, depression, and knee pain and function assessed using the Western Ontario and McMaster University Index (WOMAC). Patients completed the WOMAC at 6- and 12-months after arthroplasty. WOMAC pain and function scores were converted to interval scale and the association of PCS and changes of WOMAC pain and function were evaluated in generalized linear regression models with adjustment with confounding variables. Of the 1136 patients who underwent arthroplasty (70% female, 84% Chinese, 92% total knee arthroplasty), 1102 and 1089 provided data at 6- and 12-months post-operatively. Mean (± SD) age of patients was 65.9 (± 7.0) years. PCS was associated with a change in WOMAC pain at both 6-months and 12-months (β = - 0.04, 95% confidence interval: - 0.06, - 0.02; P < 0.001) post-operatively after adjustment in multivariable models; as well as change in WOMAC function at 6-months and 12-months. In this large cohort study, pre-operative pain catastrophizing was associated with lower improvements in pain and function at 6-months and 12-months after arthroplasty.

UNASSIGNED: Knee laxity can be experienced as knee instability which may lead to a limitation in the activity of patients. Current methods to determine knee instability are performed in a static setting, which does not always correlate with dynamic knee laxity during activities. Wearables might be able to measure knee laxity in a dynamic setting and could be of added value in the diagnosis and treatment of excessive knee laxity. Therefore, the aim of this systematic review is to provide an overview of the wearables that have been developed and their ability to measure knee laxity during dynamic activities.
UNASSIGNED: The PRISMA guidelines for systematic reviews were followed. A literature search was conducted in EMBASE, PubMed and Cochrane databases. Included studies assessed patients with knee instability using a non-invasive wearable sensor system during dynamic activity, with comparison to a reference system or healthy knees. Data extraction was performed by two authors via a predefined format. The risk of bias was assessed by The Dutch checklist for diagnostic tests.
UNASSIGNED: A total of 4734 articles were identified. Thirteen studies were included in the review. The studies showed a great variety of patients, sensor systems, reference tests, outcome measures and performed activities. Nine of the included studies were able to measure differences in patients with knee instability, all including a tri-axial accelerometer. Differences were not measurable in all parameters and activities in these studies.
UNASSIGNED: Wearables, including at least a tri-axial accelerometer, seem promising for measuring dynamic knee laxity in the anterior-posterior and mediolateral direction. At this stage, it remains unclear if the measured outcomes completely reflect the knee instability that patients experience in daily life.
UNASSIGNED: Level III.

UNASSIGNED: Recommendations discouraging high levels of physical activity and sports following unicompartmental (UKA) and total knee arthroplasty (TKA) have been questioned in recent years. This scoping review aimed to summarize the literature examining the impact of physical activity level and sports participation on implant integrity and failure in patients following UKA and TKA.
UNASSIGNED: Five databases (Medline, Embase, SCOPUS, CINAHL, ProQuest) were searched up to April 17, 2024. Retrospective, prospective and cross-sectional studies were included if they assessed the impact of physical activity level and/or sports participation (exposure variables) on implant integrity and/or failure (outcome variables) at ≥1 year following UKA or TKA. Two authors independently conducted abstract/full text reviews and data charting. Extracted data were summarized using descriptive analysis.
UNASSIGNED: Of 2014 potential records, 20 studies (UKA: n ​= ​6 studies, 2387 patients/TKA: n ​= ​14 studies, 7114 patients) met inclusion criteria. Following both UKA & TKA, most patients regularly participated in light to moderate physical activities and lower impact sports (e.g. walking, cycling, golf). No studies reported a deleterious effect of physical activity level or sports participation on implant integrity or failure post UKA (mean follow-up: 3.3-10.3 years). Three studies reported an association between greater levels of physical activity with increased risk of implant failure post TKA (mean follow-up: 1-11.4 years).
UNASSIGNED: No studies demonstrated an association between greater levels of physical activity and sports participation with increased implant wear or failure post UKA, whereas results were mixed following TKA. There is a need for large, prospective cohort studies with long-term follow-up.