Outcomes in orthopedic device infections due to Streptococcus agalactiae: a retrospective cohort study.

BACKGROUND: Group B streptococci (Streptococcus agalactiae) (GBS) is a rare cause of prosthetic joint infection (PJI) occurring in patients with comorbidities and seems to be associated with a poor outcome. Depiction of GBS PJI is scarce in the literature. METHODS: A retrospective survey in 2 referral centers for bone joint infections was done Patients with a history of PJI associated with GBS between 2014 and 2019 were included. A descriptive analysis of treatment failure was done. Risk factors of treatment failure were assessed. RESULTS: We included 61 patients. Among them, 41 had monomicrobial (67%) infections. The median duration of follow-up was 2 years (interquartile range 2.35) Hypertension, obesity, and diabetes mellitus were the most reported comorbidities (49%, 50%, and 36% respectively). Death was observed in 6 individuals (10%) during the initial management. The rate of success was 63% (26/41). Removal of the material was not associated with remission (p = 0.5). We did not find a specific antibiotic regimen associated with a better outcome. CONCLUSION: The results show that S. agalactiae PJIs are associated with high rates of comorbidities and a high treatment failure rate with no optimal treatment so far.

Threshold for anterior acetabular component overhang correlated with symptomatic iliopsoas impingement after total hip arthroplasty.

Aims: Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA. Methods: We analyzed the CT scans of 622 patients (758 THAs) between May 2011 and May 2020. From this population, we identified 136 patients with symptoms suggestive of IP impingement. Among them, six were subsequently excluded: three because the diagnosis was refuted intraoperatively, and three because they had another obvious cause of impingement, leaving 130 hips (130 patients) in the study (impingement) group. They were matched to a control group of 138 asymptomatic hips (138 patients) after THA. The anterior acetabular component overhang was measured on an axial CT slice based on anatomical landmarks (orthogonal to the pelvic axis). Results: The impingement group had a median overhang of 8 mm (interquartile range (IQR) 5 to 11) versus 0 mm (IQR 0 to 4) for the control group (p < 0.001). Using receiver operating characteristic curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%; positive predictive value 75%, negative predictive value 85%). Conclusion: Pain after THA related to IP impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of IP irritation or another reason for the pain after THA before concluding that impingement is present.

Sleep Apnea is Not an Obstacle for Outpatient Hip and Knee Arthroplasty.

BACKGROUND: Up to 25% of patients requiring hip or knee arthroplasty have sleep apnea (SA), and these patients have historically been excluded from outpatient programs. The objectives of this study were to evaluate same-day discharge failure as well as 30-day complications, readmissions, and unexpected visits. METHODS: A retrospective case-control study comparing patients who have and do not have SA matched for age, sex and arthroplasty type (total hip arthroplasty, total knee arthroplasty, unicompartimental knee arthroplasty) who underwent primary outpatient surgery between February 2019 and December 2022 in 2 academic hospitals was conducted. Cases with mild SA, moderate SA with a body mass index (BMI) <35, and SA of all severity treated by continuous positive airway pressure machines were eligible. There were 156 patients included (78 cases). Complications were assessed according to the Clavien-Dindo Classification and the Comprehensive Complication Index. Continuous variables were evaluated by Student's T or Mann-Whitney tests, while categorical data were analyzed by Chi-square or Fisher tests. Univariate analyses were performed to determine discharge failure risk factors. RESULTS: There were 6 cases (7.7%) and 5 controls (6.4%) who failed to be discharged on surgery day (P = .754), with postoperative hypoxemia (6, [3.8%]) and apnea periods (3, [1.9%]) being the most common causes. Higher BMI (odds ratio = 1.19, P = .013) and general anesthesia (odds ratio = 11.97, P = .004) were found to be risk factors for discharge failure. No difference was observed on 30-day readmissions (P = .497), unexpected visits (P = 1.000), and complications on the Clavien-Dindo Classification (P > .269) and Comprehensive Complication Index (P > .334) scales. CONCLUSIONS: Selected patients who have SA can safely undergo outpatient hip or knee arthroplasty. Higher BMI and general anesthesia increased the odds of same-day discharge failure. LEVEL OF EVIDENCE: Level III, Case-control Study.

Accuracy of the GeneXpert® MRSA/SA SSTI test to diagnose methicillin-resistant Staphylococcus spp. infection in bone fixation and fusion and management of infected non-unions.

INTRODUCTION: The GeneXpert® MRSA/SA SSTI (Methicillin Resistant Staphylococcus aureus/S. aureus skin and soft tissue infection) PCR test allows early detection of methicillin resistance in staphylococci. This test was developed for skin infections and has been evaluated for prosthetic joint infections but, to our knowledge, has not been evaluated for hardware infections outside of arthroplasties. Furthermore, we conducted a retrospective study in patients with non-prosthetic osteosynthesis hardware aiming: (1) to identify the diagnostic values of the PCR test compared to conventional cultures and the resulting rate of appropriate antibiotic therapy; (2) to identify the rate of false negative (FN) results; (3) to identify and compare the rates of failure of infectious treatment (FN versus others); (4) to search for risk factors for FN of the PCR test. HYPOTHESIS: The PCR test allowed early and appropriate targeting of antibiotic therapy. MATERIAL AND METHODS: The results of PCR tests and conventional cultures for osteoarticular infections of non-prosthetic hardware over four years (2012-2016) were compared to identify the diagnostic values of using the results of conventional culture as a reference and the rate of appropriate antibiotic therapies. Infectious management failures between the results of the FN group and the others were compared, and variables associated with a FN of the PCR test were identified. RESULTS: The analysis of 419 PCR tests allowed us to establish a sensitivity of 42.86%, a specificity of 96.82%, a positive predictive value of 60% and a negative predictive value of 93.83%. Using the results of the PCR test for the targeting of postoperative antibiotic therapy, it was suitable for staphylococcal coverage in 90.94% (381/419). The rates of patients for whom infectious treatment failed were not significantly different between the FN group and the other patients (20.8% versus 17.7%, respectively; Hazard Ratio=1.12 (95%CI 0.47-2.69, p=0.79)). A skin opening during the initial trauma (p=0.005) and a polymicrobial infection were significantly associated with a risk of FN from the PCR test (p<0.001). CONCLUSION: The PCR test makes it possible to reduce the duration of empirical broad-spectrum antibiotic therapy during the treatment of an infection of osteosynthesis hardware but causes a lack of antibiotic coverage in 9.06% of cases. LEVEL OF EVIDENCE: III; diagnostic case control study.

Gait pattern analysis before and after periacetabular osteotomy in unilaterally affected dysplastic patients.

BACKGROUND: Patients with acetabular dysplasia have an abnormal acetabular geometry which results in insufficient coverage of the femoral head. This coverage deficiency reduces contact surfaces within the joint, accelerating the wear of the articular cartilage and predisposing patients to early osteoarthritis. Periacetabular osteotomy is a surgical treatment of acetabular dysplasia that aims to reorient the acetabulum relative to the femoral head, increasing coverage. METHODS: Pelvic kinematics and lower limbs joint kinematics and kinetics during the stance phase of gait were recorded using a 3D motion capture system and force plates, then compared pre- to post- and between limbs with a repeated measures 2-way ANOVA. Radiographic measurements and gait parameters were compared pre- to post-surgery using a t-test for dependant samples. To identify predictors of pelvic symmetry improvements during gait, a multivariate analysis was performed using a forward stepwise linear regression. FINDINGS: Radiographic measurements improved for all participants while gait parameters remained unchanged. Hip flexion symmetry was improved following surgery. The external rotation moment of the healthy hip was reduced after surgery (-29%) resulting in increased asymmetry. Pelvic tilt was significantly greater on the affected side (+0.5°) during the loading response, and the difference tended to be greater after surgery (+0.8°). INTERPRETATION: Unilaterally affected dysplastic patients have an asymmetrical gait pattern that is only partially corrected by periacetabular osteotomy even when radiographic and clinical targets are met. Differences between the limbs could be explained in part by a learned antalgic pattern and muscle weaknesses leading to complex compensation mechanisms.

Lateral knee laxity increases the risk of excessive joint line obliquity after medial opening-wedge high tibial osteotomy.

BACKGROUND: Medial opening-wedge high tibial osteotomy (HTO) is a well-recognized treatment for patient with varus knee osteoarthritis. Joint line obliquity has recently been suggested to negatively impact clinical outcomes following HTO, but little is known about what factors lead to increased joint line obliquity. The purpose of the current study was (1) to evaluate whether increased preoperative lateral knee laxity, represented by the joint line convergence angle, results in increased joint line obliquity in a consecutive series of patients treated with HTO and (2) to determine the effect of advanced arthritic changes on joint line obliquity. HYPOTHESIS: Increased joint line convergence angle would be associated with increased joint line obliquity. PATIENTS AND METHODS: All HTOs performed at our center between 2010-2017 were retrospectively reviewed. Patients were excluded if pre- and postoperative standing alignment radiographs were not available. Varus-producing osteotomies were excluded. Patients were subdivided according to their preoperative joint line convergence angle (≤3° or >3°) and the degree of radiographic arthritic change. The primary outcome measure was the postoperative joint line obliquity. Categorical variables were compared using the paired samples t-test. Survival analysis was performed for failure and overall rate of reoperation. RESULTS: During the study period, 90 HTO were performed, and 38 patients (42 knees; M/F: 32/6; mean age: 41.6; mean follow-up: 4.72 years) met the inclusion criteria. The most common surgical indications were varus knee osteoarthritis (n=27, 64.3%) and osteochondritis dissecans (n=7, 8.2%). Patients with a preoperative joint line convergence angle >3° demonstrated significantly greater joint line obliquity postoperatively as compared to those with a joint line convergence angle ≤3° (6.4°±4.6° vs. 2.5°±5.7°, respectively; p=0.02). Patients with advanced arthritic changes had significantly lower preoperative (-3°±3.4° vs. -5.6°±4.1°; p=0.03) and greater postoperative (5.8°±4° vs. 2.2°±6.4°; p=0.04) joint line obliquity as compared to those with minimal arthritic changes. There were 12 complications among the 42 procedures: one conversion to total knee replacement (TKR), one hardware failure (fixation revised), one infection, and 9 hardware removals. Overall survival using conversion to TKR was 96.23% (95% CI 0.92-1.0) at 10 years. DISCUSSION: Lateral knee laxity, as defined by a preoperative joint line convergence angle >3°, and advanced arthritic changes are associated with increased postoperative joint line obliquity following medial opening-wedge high tibial osteotomy. Soft-tissue adaptation should be accounted for in order to avoid excessive joint line obliquity following high tibial osteotomy, and the planned correction should be reduced by 25% in patients with a preoperative joint line convergence angle >3° when templating using standing alignment radiographs. LEVEL OF EVIDENCE: IV.

Long-term results (after a mean 11.3years, and up to 22years, of follow-up) of the Legacy Constrained Condylar Knee (LCCK™) in primary total knee arthroplasty.

INTRODUCTION: The use of a sliding prosthesis in total knee arthroplasty (TKA) with increased stress is an intermediate solution in primary surgery, between posteriorly stabilized prostheses and hinged prostheses, in cases of ligamentous laxity and/or loss of bone substance. Favorable results have been reported in the medium term but to our knowledge, this type of prosthesis has not been evaluated in Europe beyond 10 years of follow-up. We therefore conducted a retrospective study in order to carry out: 1) the study of the survival of the Legacy Constrained Condylar Knee (LCCK™) prosthesis in primary surgery, 2) the analysis of complications, functional scores and radiographic data, 3) the analysis of the link between the diaphyseal filling rate and prosthetic loosening. HYPOTHESIS: The LCCK™ sliding prosthesis with increased constraint has equivalent long-term survival and clinical results to standard posteriorly stabilized TKA and superior to hinged TKA. MATERIAL AND METHOD: A retrospective series of 141 LCCK™ implanted in 134 patients between 1997 and 2010 was analyzed. Survival was assessed with censoring through an evaluation of partial or total revision of the implants. The functional results were evaluated using the IKS and Oxford 12 scores. Data regarding the Canal Fill Ratio (CFR) and the presence of pathological periprosthetic lines were also collected. RESULTS: The average follow-up was 11.3±5.3years with a maximum follow-up of 22.7years. Survival at 20years was 90.8% [95% CI: 83.7-95.7]. The rate of early complications was 13.5% (19/141), predominantly comprised of venous thrombosis (6/141), hematomas (3/141 including two requiring surgical drainage), stiffness (3/141) and early infections (3/141). The rate of late complications was 17% (24/141), led by stiffness (4.4%; 6/141), infections (2.9%; 4/141) and hardware failure (2. 2%; 3/141). Ten of the 141 patients (7.1%) had LCCK failure, including 3 (2.1%) for stiffness, 3 (2.1%) for hardware failure, 2 (1.4%) for infection, 1 (0.7%) for laxity and 1 (0.7%) for a periprosthetic fracture. No aseptic loosening was found. The total IKS score went from 65 [0-116] to 143 [79-200] at follow-up, the IKS knee score went from 30 [0-66] to 85 [44-100], and the IKS function score went from 35 [0-70] to 57 [0-100]. The Oxford score went from 14 [2-25] to 34 [15-48] at follow-up. Only two patients (1.4%) presented with a partial periprosthetic line. The tibial CFR was 0.81 and the femoral CFR was 0.76. The influence of the CFR could not be analyzed due to the absence of loosening. DISCUSSION: The LCCK™ prosthesis in primary surgery has good medium-term survival, a significant improvement in functional scores and a complication rate comparable to posteriorly stabilized prostheses. The complication rate is lower than that of hinged prostheses. LEVEL OF EVIDENCE: IV; single-center retrospective study.

The impact of Canadian-produced research on the global orthopedic literature: a bibliometric analysis.

BACKGROUND: Little is known about the quality and impact of Canadian-produced research relative to that of other developed nations. The purpose of this study was to determine the contribution of Canadian authors to the orthopedic literature globally and nationally as well as Canada's research productivity in orthopedics. We hypothesized that Canada ranks among the most impactful countries in terms of orthopedic research productivity. METHODS: We performed a bibliometric analysis to identify articles published between 2001 and 2020 in the category of orthopedics. We identified Canada's global rank in terms of overall productivity and assessed the contributions of individual Canadian authors. We also examined the quality of publications as determined by category normalized citation impact (CNCI) and publication in the top quartile of journals (%Q1) in terms of impact factor. In addition, we calculated the percentage of Canadian publications that were in orthopedics. RESULTS: We identified 10 821 orthopedic publications from 2001 to 2020. Canada placed sixth globally in terms of productivity in orthopedic research. The annual productivity of Canadian orthopedic researchers increased over the study period by a factor of 3.2. In terms of research quality, with a %Q1 of 36.5% and a CNCI of 1.22, Canada outperformed Asian countries and the United States; the latter country had a %Q1 of 35.3% and a CNCI of 1.14 over the study period. CONCLUSION: The body of Canadian orthopedic literature has grown consistently over the past 20 years. Despite the overall leadership of the United States and other developed nations such as China and Japan, Canada ranks among the most influential countries in terms of the quality and quantity of orthopedic research.

Bibliometric evaluation of negative publications from orthopedics and traumatology from the ten most influential journals of 2009-2010 and 2019-2020: A comparative study with the "Orthopedics & Traumatology: Surgery & Research" journal, using the same analysis of submitted and accepted articles.

BACKGROUND: There is a paucity of data in the literature regarding negative articles concerning surgery in orthopedics and trauma. Knowledge pertaining to treatments or techniques which confer a beneficial effect remains important, as does knowledge regarding those which have a null or pejorative effect. Thus, this study was carried out on negative articles in order to: (1) determine their proportion in the ten predominant journals concerning orthopedic and trauma surgery; (2) assess variability in their publication rate depending on the journal and the year, and compare their citation rate to that of positive articles; (3) specify whether a positive article was more likely to be cited compared to a negative article; (4) carry out the same bibliometric analysis with the "Orthopedics & Traumatology: Surgery & Research (OTSR)" journal, and detect possible selection bias for negative articles during the review. HYPOTHESIS: There are fewer negative articles than positive articles in the literature relating to orthopedic and trauma surgery. MATERIAL AND METHOD: The study was carried out using the ten orthopedic and trauma surgery journals with the highest impact factors for the year 2021. Two periods were compared, 2009-2010 and 2019-2020. Among the 17,812 publications obtained, 11,962 publications were retained to carry out the analysis (technical notes, meta-analyses, editorials and letters to the editor were all excluded). An analysis using the same method was carried out on the 3,727 articles submitted to OTSR from 2015 to 2021, which made it possible to compare the rejected articles to the accepted articles. RESULTS: Negative articles represented 11% (1,342/12,023) of the literature relating to orthopedic and trauma surgery. There were differences in the rate of publication of negative articles depending on the journals (from 4.04% to 17.14%) (p<0.0001). The negative article publication rate did not change between the two periods studied: 534/4963 articles (10.76%) in 2009-2010 versus 802/6999 (11.46%) in 2019-2020 (p=0.23). Positive articles were not cited more often than negative ones: no significant difference between the Category Normalized Citation Impact (CNCI) classes (respectively for classes 0;1[/[1;2[/≥ 2 with 45.66% 28.22% and 26.12% for negative articles versus 44.90% 27.46% and 27.64% for positive articles [p=0.4]) and the Top10% (with 18.86% for negative articles versus 20.10% for positive ones [p=0.28]). The OTSR journal had a rate of negative articles of 9.46% which was within the average range of the journals studied. A selection bias (p<0.02) for negative articles during the review of the OTSR journal was identified with fewer negative articles accepted (115/1216 [9.46%]) than positive articles (164/1330 [12.33%]). DISCUSSION: The publication of negative articles varies according to the journals and although it is modest, at only 11%, it is essential because it allows us not to repeat errors but also not to bias the carrying out of meta-analyses, and among other things to avoid useless studies. LEVEL OF EVIDENCE: III; case control study from the literature.

Validation of the French version of the Non-Arthritic Hip Score (NAHS) in 113 hip arthroscopy procedures.

BACKGROUND: The Non-Arthritic Hip Score (NAHS) used to evaluate the hip in younger patients is a self-administered questionnaire with 20 items in four sections: pain, symptoms, function, and activities. Although used in France, no transcultural version had been validated. The objective of this study was to translate the NAHS into French then assess the validity, reliability, and sensitivity to change of the French-language version (NAHS-Fr) in younger patients with hip conditions other than osteoarthritis. HYPOTHESIS: The NAHS-Fr demonstrates good validity and reliability when used in younger French-speaking patients with hip pain. MATERIAL AND METHODS: We conducted a prospective observational study in 105 patients (62 males and 43 females) scheduled for surgery on one or both hips (113 hips in total) to treat cam-type femoro-acetabular impingement or labral lesions. Before and 6 months after surgery, each patient completed the NAHS-Fr and Western Ontario and McMaster Osteoarthritis Index (WOMAC). Statistical tests were done to evaluate validity, reliability, and sensitivity to change, as recommended by the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN). RESULTS: The response rate was 100%, confirming that the NAHS-Fr was easy to use. The NAHS-Fr was both valid and reliable. No ceiling or floor effect was detected for the total NAHS-Fr score. All items had Cronbach alpha coefficients greater than 0.8, indicating good internal consistency. External consistency between the NAHS-Fr and WOMAC was negative (-0.676) due to inversely proportional score indexing. Before surgery, the NAHS-Fr and WOMAC scores were strongly and significantly correlated (p<0.0001). The effect size was greater than 0.8, indicating good sensitivity to the change induced by surgery. DISCUSSION: These results confirm the study hypothesis: the NAHS-Fr has the same good psychometric characteristics as does the original version and versions in other languages. The NAHS-Fr is useful for evaluating younger patients with non-osteoarthritic hip pain and can be used by French-speaking surgeons in everyday clinical practice. LEVEL OF EVIDENCE: IV, prospective observational non-comparative cohort study.

What is the rate of text generated by artificial intelligence over a year of publication in Orthopedics & Traumatology: Surgery & Research? Analysis of 425 articles before versus after the launch of ChatGPT in November 2022.

BACKGROUND: The use of artificial intelligence (AI) is soaring, and the launch of ChatGPT in November 2022 has accelerated this trend. This "chatbot" can generate complete scientific articles, with risk of plagiarism by mining existing data or downright fraud by fabricating studies with no real data at all. There are tools that detect AI in publications, but to our knowledge they have not been systematically assessed for publication in scientific journals. We therefore conducted a retrospective study on articles published in Orthopaedics & Traumatology: Surgery & Research (OTSR): firstly, to screen for AI-generated content before and after the publicized launch of ChatGPT; secondly, to assess whether AI was more often used in some countries than others to generate content; thirdly, to determine whether plagiarism rate correlated with AI-generation, and lastly, to determine whether elements other than text generation, and notably the translation procedure, could raise suspicion of AI use. HYPOTHESIS: The rate of AI use increased after the publicized launch of ChatGPT v3.5 in November 2022. MATERIAL AND METHODS: In all, 425 articles published between February 2022 and September 2023 (221 before and 204 after November 1, 2022) underwent ZeroGPT assessment of the level of AI generation in the final English-language version (abstract and body of the article). Two scores were obtained: probability of AI generation, in six grades from Human to AI; and percentage AI generation. Plagiarism was assessed on the Ithenticate application at submission. Articles in French were assessed in their English-language version as translated by a human translator, with comparison to automatic translation by Google Translate and DeepL. RESULTS: AI-generated text was detected mainly in Abstracts, with a 10.1% rate of AI or considerable AI generation, compared to only 1.9% for the body of the article and 5.6% for the total body+abstract. Analysis for before and after November 2022 found an increase in AI generation in body+abstract, from 10.30±15.95% (range, 0-100%) to 15.64±19.8% (range, 0-99.93) (p < 0.04; NS for abstracts alone). AI scores differed between types of article: 14.9% for original articles and 9.8% for reviews (p<0.01). The highest rates of probable AI generation were in articles from Japan, China, South America and English-speaking countries (p<0.0001). Plagiarism rates did not increase between the two study periods, and were unrelated to AI rates. On the other hand, when articles were classified as "suspected" of AI generation (plagiarism rate ≥ 20%) or "non-suspected" (rate<20%), the "similarity" score was higher in suspect articles: 25.7±13.23% (range, 10-69%) versus 16.28±10% (range, 0-79%) (p < 0.001). In the body of the article, use of translation software was associated with higher AI rates than with a human translator: 3.5±5% for human translators, versus 18±10% and 21.9±11% respectively for Google Translate and DeepL (p < 0.001). DISCUSSION: The present study revealed an increasing rate of AI use in articles published in OTSR. AI grades differed according to type of article and country of origin. Use of translation software increased the AI grade. In the long run, use of ChatGPT incurs a risk of plagiarism and scientific misconduct, and needs to be detected and signaled by a digital tag on any robot-generated text. LEVEL OF EVIDENCE: III; case-control study.

Management of medial femorotibial osteoarthritis: Epidemiology, and survival of unicompartmental knee arthroplasty versus valgus high tibial osteotomy in France. Study of 108,007 cases from the French National Hospitals Database.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) and valgus high tibial osteotomy (HTO) are two options for isolated medial femorotibial osteoarthritis in genu varum. In the absence of registries for osteotomies and for arthroplasty in the knee, epidemiological data are hard to obtain in France. We therefore performed a retrospective study, with the aims of: 1) estimating UKA and HTO survival without revision by total knee arthroplasty (TKA), and 2) assessing risk factors for revision according to treatment group. HYPOTHESIS: Medium-term survival is better with HTO than UKA in under-70-year-olds. MATERIALS AND METHOD: All elderly patients undergoing HTO or UKA in the French National Hospitals Database for the period 2011-2020 were included: i.e., 108,007 patients; 43,537 HTO (29,330 male, 14,207 female; mean age 49.7 years, 95% CI 49.6-49.8) and 64,470 UKA (31,181 male, 33,289 female; mean age 60.5 years, 95% CI 60.5-60.6). RESULTS: Survival free of revision by TKA was 75.8% (95% CI=75.2-76.4) for UKA and 80.6% (95% CI=80.0-81.3) for HTO (p<0.00001). In UKA, revision risk factors comprised: low annual center volume (<17 UKAs per year) (HR=1.50; 95% CI=1.41-1.59), obesity (HR=1.25; 95% CI=1.18-1.32), and age <60years, with maximum risk for 50-59years (HR=2.41; 95% CI=1.83-3.16 in 50-59 year-olds). In HTO, revision risk factors comprised: obesity (HR=1.42; 95% CI=1.31-1.53), rheumatoid arthritis (HR=2.75; 95% CI=1.37-5.51), joint chondrocalcinosis (HR=2.01; 95% CI=1.18-3.39), and age >60years (HR=8.81; 95% CI=7.23-19.73 in 60-69-year-olds). Male gender was a protective factor against revision in both groups: UKA, HR=0.75 (95% CI=0.72-0.79); HTO, HR=0.73 (95% CI=0.69-0.77). The number of UKAs increased over the years, matching the increase in arthroplasty in France, with a decrease in HTOs until 2019. CONCLUSION: HTO showed better medium-term survival than UKA in under-70-year-olds in France. Even so, indications decreased in favor of UKA, although the respective risk factors differ. These findings suggest that conservative surgery still has a role, depending on osteoarthritis stage. LEVEL OF EVIDENCE: III; retrospective comparative study.

Recovery of leg strength based on isokinetic testing after tumor resection and reconstruction with a modular rotating hinge knee system: Prospective cross-sectional study with a minimum follow-up of 24 months.

BACKGROUND: While modular reconstruction implants can be used to replace the bone lost after bone tumor resection, tumor excision from the neighboring soft tissues can lead to loss of strength and joint range of motion (ROM), which results in worse knee function. Functional recovery after total knee arthroplasty for osteoarthritis has been extensively documented. But few studies have evaluated the recovery after total knee reconstruction following tumor excision despite the fact that most of these patients are young and have high functional demands. We did a prospective cross-sectional study to: 1) compare muscle strength recovery around the knee with an isokinetic dynamometer after tumor excision and reconstruction with a modular implant to the healthy contralateral knee; 2) determine if the differences in peak torque (PT) in the knee extensors and flexors had a clinical impact. HYPOTHESIS: Resection of soft tissues during tumor excision around the knee causes strength loss that cannot be fully recovered. METHODS: The 36 patients who underwent extra- or intra-articular resection of a primary or secondary bone tumor in the knee area followed by reconstruction with a rotating hinge knee system between 2009 and 2021 were eligible for this study. The primary outcome was the ability to actively lock the operated knee. The secondary outcomes were the concentric PT during isokinetic testing at slow (90°/sec) and fast (180°/sec) speeds, flexion-extension ROM, Musculoskeletal Tumor Society (MSTS) score, the IKS, Oxford Knee Score (OKS) and KOOS. RESULTS: Nine patients agreed to participate in the study, all of whom had regained the ability to lock their knee postoperatively. PT in flexion and extension on the operated knee was less than the healthy knee. The PT ratio for the operated/healthy knee at 60°/sec and 180°/sec in flexion was 56.3%±16.2 [23.2-80.1] and 57.8%±12.3 [37.7-77.4], respectively, which corresponded to a slow-speed strength deficit of 43.7% in the knee flexors. The PT ratio for the operated/healthy knee at 60°/sec and 180°/sec in extension was 34.3%±24.6 [8.6-76.5] and 43%±27.2 [13.1-93.4], respectively, which corresponded to a slow-speed strength deficit of 65.7% in the knee extensors. The mean MSTS was 70%±20 [63-86]. The OKS was 29.9/48±11 [15-45], the mean IKS knee was 149.6±36 [80-178] and the mean KOOS was 67.43±18.5 [35-88.7]. DISCUSSION: Despite all patients having the ability to lock out their knee, there was an imbalance in the strength between opposite muscle groups: 43.7% strength deficit at slow-speed and 42.2% at fast speed for the hamstring muscles, and 65.7% at slow-speed and 57% at fast speed for the quadriceps muscles. This difference is considered pathological with an increased risk of knee injury. Despite this strength deficit, this joint replacement technique, which is free of complications, can preserve good knee function with acceptable knee joint ROM and satisfactory quality of life. LEVEL OF EVIDENCE: III; prospective cross-sectional case-control study.

In Vitro and In Vivo Evaluation of a Bio-Inspired Adhesive for Bone Fixation.

Compared to metallic hardware, an effective bone adhesive can revolutionize the treatment of clinically challenging situations such as comminuted, articular, and pediatric fractures. The present study aims to develop such a bio-inspired bone adhesive, based upon a modified mineral-organic adhesive with tetracalcium phosphate (TTCP) and phosphoserine (OPS) by incorporating nanoparticles of polydopamine (nPDA). The optimal formulation, which was screened using in vitro instrumental tensile adhesion tests, was found to be 50%molTTCP/50%molOPS-2%wtnPDA with a liquid-to-powder ratio of 0.21 mL/g. This adhesive has a substantially stronger adhesive strength (1.0-1.6 MPa) to bovine cortical bone than the adhesive without nPDA (0.5-0.6 MPa). To simulate a clinical scenario of autograft fixation under low mechanical load, we presented the first in vivo model: a rat fibula glued to the tibia, on which the TTCP/OPS-nPDA adhesive (n = 7) was shown to be effective in stabilizing the graft without displacement (a clinical success rate of 86% and 71% at 5 and 12 weeks, respectively) compared to a sham control (0%). Significant coverage of newly formed bone was particularly observed on the surface of the adhesive, thanks to the osteoinductive property of nPDA. To conclude, the TTCP/OPS-nPDA adhesive fulfilled many clinical requirements for the bone fixation, and potentially could be functionalized via nPDA to offer more biological activities, e.g., anti-infection after antibiotic loading.

Should microbiological samples be taken routinely when performing revision surgery for post-surgical hematoma after hip or knee replacement? Retrospective study of 78 cases of surgically drained hematoma with a minimum follow-up of 2 years.

INTRODUCTION: The relationship between the occurrence of a periprosthetic hip or knee joint infection, a post-surgical hematoma and the time to surgical revision, along with the need to take samples for microbiology analysis has not been clearly defined. This led us to perform a retrospective study to: 1) define the rate of infected hematoma and subsequent infection after surgical revision for hematoma and 2) analyze in which time frame the hematoma was likely to be infected. HYPOTHESIS: The more time elapsed before the postoperative hematoma is drained surgically after hip or knee replacement, the higher the hematoma infection rate and the late infection rate. PATIENTS AND METHODS: Between 2013 and 2021, 78 patients (48 hip and 30 knee replacements) who had a postoperative hematoma without signs of infection upon draining were included in the study. Surgeons decided whether samples for microbiology were collected (33/78 patients (42%)). The data compiled consisted of the patient's demographics, the risk factors for infection, number of infected hematomas, number of subsequent infections at a minimum follow-up of 2 years, and the time to revision surgery (lavage). RESULTS: Of the 27 samples collected from the hematoma during the first lavage, 12/27 (44%) were infected. Of the 51 that did not have samples collected initially, 6/51 (12%) had them collected during the second lavage; 5 were infected and 1 was sterile. Overall, 17/78 (22%) of the hematomas were infected. Conversely, there were no late infections at a mean follow-up of 3.8 years (min 2, max 8) after the hematoma was drained in any of the 78 patients. The median time to revision was 4 days (Q1=2, Q3=14) for non-infected hematomas that were drained surgically versus 15 days (Q1=9, Q3=20) for hematomas that were found to be infected (p=0.005). No hematoma was infected when it was drained surgically within 72hours post-arthroplasty (0/19 (0%)). The infection rate went up to 2/16 (12.5%) when it was drained 3 to 5 days later and 15/43 (35%) when it was drained after more than 5 days (p=0.005). We believe this justifies collecting microbiology samples immediately when the hematoma is drained more than 72hours after the joint replacement procedure. Diabetes was more prevalent in patients who had an infected hematoma (8/17 [47%] versus 7/61 [11.5%], p=0.005). The infection was due to a single bacterium in 65% of cases (11/17); S. epidermidis was found in 59% (10/17) of infections. CONCLUSION: The occurrence of a hematoma after hip or knee replacement that requires surgical revision is associated with increased risk of infection, since the hematoma infection rate was 22%. Since hematomas drained within 72hours are less likely to be infected, samples do not need to be collected for microbiology at that time. Conversely, any hematomas being drained surgically beyond this time point should be considered as infected, thus microbiology samples should be collected, and empirical postoperative antibiotic therapy initiated. Early revision may prevent the occurrence of late infections. The standard treatment of infected hematomas appears to resolve the infection at a minimum follow-up of 2 years. LEVEL OF EVIDENCE: Level IV Retrospective study.

Trajectory of chronic and neuropathic pain, anxiety and depressive symptoms and pain catastrophizing after total knee replacement. Results of a prospective, single-center study at a mean follow-up of 7.5 years.

INTRODUCTION: A considerable number of patients are not satisfied after total knee replacement (TKR) because of persistent pain. This pain can also be neuropathic in origin. Both types of pain have a large impact on function and quality of life. Furthermore, the trajectory of anxiety and depressive symptoms and pain catastrophizing has rarely been studied after TKR surgery. The primary objective of this study was to define the trajectory of knee pain after primary TKR. The secondary objectives were to evaluate how neuropathic pain, anxiety and depressive symptoms and pain catastrophizing change over time. METHODS: This prospective, single-center study included patients who underwent primary TKR for primary osteoarthritis between July 2011 and December 2012. Personal data (age, sex, body mass index, knee history, operated side, surgical approach, type of implant, operative time, and rehabilitation course) and the responses to seven questionnaires (Numerical pain rating scale, DN4-interview for neuropathic pain, Oxford Knee Scale, Hospital and Anxiety Depression Scale, Beck Depression Inventory, Patient Catastrophizing Scale and Brief Pain Inventory) were determined preoperatively, at 6 months postoperative and at a mean follow-up of 7.5 years. RESULTS: Preoperatively, 129 patients (35 men, 94 women) filled out all the questionnaires. Subsequently, 32 patients were excluded because of incomplete responses at 6 months postoperative, 6 were excluded because they had undergone revision surgery, 11 patients were lost to follow-up and 5 patients had died. In the end, 65 patients were available for analysis (50% of the initial cohort) who were 74 years old on average at inclusion. Between the preoperative period and 6 months postoperative, pain (p<0.001), function (p<0.001), anxiety symptoms (p<0.001) and catastrophizing (p<0.001) had improved. Depressive symptoms did not change (p=0.63). Between 6 months postoperative and the latest follow-up, none of the parameters changed further (p>0.05). Of the 65 patients analyzed, 21% had chronic pain of undefined origin at 6 months postoperative and 26% had chronic pain at the end of follow-up, with 50% also having neuropathic pain. Preoperatively, 40% of the 65 patients had neuropathic pain, 30% at 6 months (p=0.27) and 18% at 7.5 years after TKR (p=0.01). CONCLUSION: The number of patients who have chronic pain after TKR is considerable, especially since knee pain stabilized at 6 months postoperative. Early detection is vital to prevent the pain from becoming chronic, which makes it more difficult to treat. Half the patients with persistent pain also had neuropathic pain, which should be detected before surgery so the patients can be referred to a specialized pain management center. The presence of anxiety and depressive symptoms and pain catastrophizing is not a contraindication to TKR, but these patients should be referred to specialists for treatment before surgery. LEVEL OF EVIDENCE: IV, prospective cohort study.

Reasons for delays to orthopaedic and trauma surgery: A retrospective five-year cohort.

BACKGROUND: Early surgery seeks to decrease peri-operative complication rates and mean hospital stay lengths while also improving patient satisfaction. Few data exist on optimising care before orthopaedic and trauma surgery (OTS), notably regarding delays to surgery after admission. The objective of this study was to identify reasons for OTS delays at a university-hospital OTS centre in France. Surgery was defined as delayed if performed more than 48h after admission. HYPOTHESIS: Some reasons for OTS delays are amenable to modification by measures aimed at decreasing the adverse impact of long wait times. MATERIAL AND METHOD: We conducted a retrospective single-centre observational study. Of 18 495 who underwent surgery at the OTS centre of the Clermont-Ferrand university hospital in 2015-2019, 1946 had a post-admission wait time longer than 48h. After exclusion of repeat surgical procedures and dressing changes, 1175 patients remained for the analysis. The records of each patient were reviewed to identify the reason for the surgical delay. RESULTS: A delay longer than 48h was noted for 6.3% of OTS procedures. The most common reasons were limited resource availability (e.g., of operating theatres, nurses, or anaesthesia teams) (21.3%) and patient treatment by anticoagulants (20.9%). CONCLUSION: Most delays were due to reasons independent from the patients operating-theatre logistics, delays in obtaining investigations) that could be targeted by those involved with operating-theatre management to diminish both surgical delays and hospital stay lengths. LEVEL OF EVIDENCE: IV, retrospective observational cohort study.