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.

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.

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.

Debridement, antibiotics and implant retention for prosthetic joint infection: comparison of outcomes between total hip arthroplasty and hip resurfacing.

INTRODUCTION: The management of prosthetic joint infection (PJI) has been widely studied in the context of total hip arthroplasty (THA). However, the outcomes of debridement, antibiotics and implant retention (DAIR) for PJI have never been compared between hip resurfacing arthroplasty (HRA) and THA. This led us to carry out a retrospective case-control study comparing the surgical treatment of post-operative infections between HRA and THA to determine the infection remission rate and the medium-term functional outcomes. METHODS: This single-centre case-control study analysed 3056 HRA cases of which 13 patients had a PJI treated by DAIR. These patients were age-matched with 15 infected THA hips treated by DAIR and modular component exchange (controls). Their survival (no recurrence of the infection) was compared and factors that could affect the success of the DAIR were explored: sex, body mass index, age at surgery, presence of haematoma, type of bacteria present and antibiotic therapy. RESULTS: At a mean follow-up of five years (2-7), the infection control rate was significantly higher in the HRA group (100% [13/13]) than in the THA group (67% [10/15]) (p = 0.044). More patients in the THA group had undergone early DAIR (< 30 days) (73% [11/15]) than in the HRA group (54% [7/13]). There was no significant difference between the two groups in the ASA score, presence of comorbidities, body mass index and duration of the initial arthroplasty procedure. At the review, the Oxford-12 score of 17/60 (12-28) was better in the HRA group than the score of 25/60 (12-40) in the THA group (p = 0.004). CONCLUSION: DAIR, no matter the time frame, is a viable therapeutic option for infection control after HRA.

Influence of shelf acetabuloplasty on the outcomes of total hip arthroplasty in hips with dysplasia: a case-control study.

INTRODUCTION: Total hip arthroplasty (THA) in young adults, especially in those with hip dysplasia, is affected by wear and acetabular fixation problems. Shelf acetabuloplasty is performed to delay THA in patients with acetabular dysplasia. Thus, we conducted a retrospective, continuous case-control study at a single healthcare facility to analyze (1) the influence of prior shelf acetabuloplasty on the survival of a subsequent THA and (2) the functional outcomes. MATERIALS AND METHODS: We evaluated 105 patients (124 THA) who underwent THA due to hip dysplasia: 54 patients (61 THA) were included in the THA post-shelf acetabuloplasty group (case group) and 51 patients (63 THA) in the THA for dysplasia group (control group). RESULTS: At 15 years' follow-up, 89% of patients (95% CI: 84-91%) in the shelf group and 83% (95% CI: 81-90%) in the dysplasia group had not undergone surgical revision. This difference between groups was not statistically significant (p = 0.566). The functional outcomes were satisfactory in both groups; however, they were significantly better in the dysplasia group than in the shelf group based on the Merle d'Aubigne and Postel score (16.9 vs 16.0 min-max: 14-18 vs 3-18) (p = 0.01), Harris Hip score (90.0 vs 84.7, min-max: 62-100 vs 22-100) (p = 0.017), and the Oxford-12 (18/60 vs 21/60, min-max: 45-12 vs 51-12) (p = 0.04). CONCLUSION: Shelf acetabuloplasty before THA does not negatively affect THA survivorship. The functional outcomes appear to be better in the hips that did not undergo shelf acetabuloplasty, although the results were good in both groups.

Acetabular revision for iliopsoas impingement: a study of 55 cases at 3 years of follow-up. Does the procedure achieve the Minimal Clinically Important Difference (MCID) in the Oxford-12 score in more than 80% of cases?

INTRODUCTION: Several surgical options can be offered to manage iliopsoas impingement. Research published on cup replacements often concerns a small population size or multicentre studies, suggesting a variety of indications. We conducted a retrospective single centre study screening according to a specific protocol of a population of patients who had a cup replacement for iliopsoas impingement. The objectives were: 1) to specify the functional outcomes and the achievement of the Minimal Clinically Important Difference (MCID) and the Patient Acceptable Symptom State (PASS) according to the Oxford-12 score, and 2) to assess the complication rate. HYPOTHESIS: Our hypothesis was that acetabular replacements achieve a Minimal Clinically Important Difference (MCID) in more than 80% of cases. PATIENTS AND METHODS: Fifty-five hips underwent acetabular revision between 2011 and 2020. Forty-three were performed as first-line surgery, eight after failed tenotomy and four after failed anterior hip capsule thickening plasty. A CT scan of all the hips revealed a median overhang of 9 mm (7; 12) and a 7 ° cup anteversion (2; 19). Follow-up included assessment of the Oxford-12 score using MCID and PASS, the Merle d'Aubigné score, an assessment of hip flexion muscle strength using the Medical Research Council scale, and an assessment of satisfaction and complications. RESULTS: At a mean follow-up of 3 years (2-10), the difference in the Oxford score before and at follow-up was 18 points (15; 27) (p < 0.001), the median Medical Research Council score was 4.5 (4; 5) and patients were satisfied or very satisfied in 73% of cases (40/55). The MCID was achieved for 87% of the hips (48/55), and the PASS was achieved in 67% of cases (33/55). The rate of complications involving surgical revision was 10.9% (6/55) with respectively: two anterior dislocations, one early infection on day 10 resolved after wound irrigation and appropriate antibiotic therapy, one intraoperative fracture of the trochanter requiring osteosynthesis and one arthroscopic revision to remove a free cement fragment. CONCLUSION: Due to a good functional outcome but a high complication rate, a cup replacement can be offered for iliopsoas impingement associated with acetabular malposition or significant overhang. LEVEL OF EVIDENCE: IV.

Patient Factors Influencing Outcomes at 12-Year Follow-up of Hip Arthroscopy for Femoroacetabular Impingement.

BACKGROUND: Arthroscopic treatment of femoroacetabular impingement has increased in popularity since the early 2000s when it was first described, although only a few midterm follow-up studies have been published. PURPOSE: To describe the outcomes of patients undergoing hip arthroscopy for femoroacetabular impingement at a mean 12-year follow-up and to determine the risk factors for failure. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The Non-Arthritic Hip Score (NAHS) and a radiographic evaluation were completed preoperatively and at midterm follow-up. Participants were divided into 2 groups according to their clinical evolution. The success group consisted of patients whose NAHS at the final follow-up was above the established Patient Acceptable Symptom State (PASS) threshold of 81.9, whereas patients who underwent a second surgical intervention or did not reach the PASS threshold at final follow-up were assigned to the failure group. These groups were compared to identify preoperative differences in demographic, pathological, and surgical factors. RESULTS: A total of 95 hips were included, after 23 were lost to follow-up (80.5% follow-up). At a mean follow-up of 12.1 years (range, 9.2-16.0 years), 9 hips required total hip arthroplasty (9.5%), 5 required revision hip arthroscopy (5.3%), 29 did not achieve the NAHS PASS threshold (30.5%), and 52 achieved the NAHS PASS threshold (54.7%). The mean NAHS was 82.4 at final follow-up compared with 66.9 preoperatively (mean difference = 15.5; P < .001). Higher mean body mass index (24.9 vs 23.0; P = .030), older age (30.0 vs 27.2; P = .035), and inferior preoperative lateral joint space width (3.9 vs 4.4; P = .019) were associated with inferior prognosis in the failure group versus success group. Osteoarthritis progression was observed in 69.2% of the failure group and in 34.8% of the success group (P = .082). Labral ossification was observed in 78.3% of all patients, and its lateral projection length was statistically associated with failure (P = .015). CONCLUSION: At a mean 12-year follow-up, hip arthroscopy for femoroacetabular impingement led to significant clinical improvement, with 55% PASS achievement. In total, 31% of patients were below the PASS threshold, 5% had revision arthroscopy, and only 9% had conversion to total hip arthroplasty for a 45% global failure rate. Increased body mass index, older age, and smaller preoperative lateral joint space width were significant negative prognostic factors. Postoperative degenerative changes were highly prevalent and demonstrated association with failure.

Do the porous custom implants have a position consistent with the planning and allow anatomical reconstruction of hip center of rotation in complex acetabular revisions Paprosky III?

INTRODUCTION: In revision total hip arthroplasty (THA), the advent of porous custom-made triflange acetabular implants with 3D scan planning offers a new perspective to improve implantation accuracy and anatomical restoration of the center of rotation (COR). This issue was investigated using CT-scan as the measurement tool, but in limited series (±10 cases) and without investigating the factors that may influence errors in positioning. Therefore we performed a retrospective study aiming to: (1) assess the placement accuracy of such implants with respect to the preoperative planning, (2) examine whether the volume of bone to be resected in order to apply the implant had an impact on this accuracy, (3) assess if errors in position at surgery had any influence on function, complications and survival. HYPOTHESIS: Preoperative planning could be accurately reproduced when implanting porous custom-made acetabular implants, and that accuracy would decrease in proportion to the volume of bone to be resected METHOD: Twenty patients undergoing THA revision with porous custom-made acetabular implants were included in this single-center retrospective study. Mean follow-up was 17.9 months ± 9.4 [2-45.1]. Preoperative planning was performed using 3D scanographic modeling. A post-operative CT scan was performed to assess implantation accuracy in terms of orientation and COR restitution. Demographic data, Oxford scores, complications and survival were recorded. RESULTS: Mean deviation from the preoperative planning in inclination, anteversion and rotation were 4.3 ° ± 2.5, 6.1 ° ± 4.7, and 7 ° ± 4.6, respectively. Restoration of the COR showed a mean deviation of 2.1 ± 1.3 mm anteroposteriorly, 2.5 ± 2 mm mediolaterally and 2.2 ± 1.3 mm proximodistally. In total, 45% (9/20) of implants were positioned with perfect restoration of orientation (±10 °) and COR (±5 mm). The mean planned bone resection was 8.1 ± 4.9 cm3, with placement accuracy and COR restitution decreasing significantly when the volume of bone to be resected exceeded 2.7 cm3. One dislocation was found (5%, 1/20). Survival at last follow-up was 100%, the mean Oxford score at follow-up was 31.7 ± 7.9 [16-52], without being influenced by errors in position or COR restitution. CONCLUSION: In total 45% of the implants restored an orientation and a COR as planned, particularly when the volume of bone to be resected is less than 2.7 cm3. Although these are complex cases with large amounts of bone loss, 3D manufacturing could give us hope of greater precision. The link between better precision and low bone resection volume could be an area to develop with the manufacturer in order to improve results. LEVEL OF EVIDENCE: III; diagnostic using CT in transversal retrospective study.

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.

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.

Can the minimal clinically important difference (MCID) for the Oxford score, KOOS and its derivatives be identified in a French sample of total knee arthroplasties?

CONTEXT: To assess the effect of a surgical procedure on a patient, it is conventional to use clinical scores before and after the procedure, but it is increasingly common and recommended to weight the results of these scores with the notion of minimal clinically important difference ("MCID"). This MCID should be determined using either the data distribution method based on score variation, or the anchor method, which uses an external question to categorize the results. MCIDs vary from one population to another, and to our knowledge there has been no investigation in France for total knee arthroplasties (TKAs). We therefore conducted a prospective study on a population of TKAs in order to: 1) Define MCID in France on a population of TKAs for the Oxford score, KOOS (Knee injury and Osteoarthritis Outcome Score) and its derivatives, 2) Determine whether MCID for these scores in France is comparable to results in the literature. HYPOTHESIS: Is the MCID for total knee arthroplasty in France comparable to other results in the literature? MATERIAL AND METHOD: This was a prospective observational study in which 218 patients (85 men, 133 women) with a mean age of 72 years [27-90] who had undergone a primary TKA out of 300 initially included responded, before and after surgery, to the Oxford-12, KOOS and Forgotten Joint Score (FJS) questions (mean follow-up 24 months). MCID was calculated using the distribution method as well as the anchor method ("improvement 1 to 5" and "improvement yes or no"). RESULTS: At a mean follow-up of 24 months [18-36], the Oxford-12 score increased from 16 ± 8 [0-41] to 34 ± 11 [6-48] (p < 0.001), all components of the KOOS score were improved and the FJS at follow-up was 47 ± 32 [0-100]. For the anchor "improvement 1 to 5", there were 14 unimproved patients, 23 patients in identical condition and 179 patients improved by surgery. For the anchor "are you improved yes/no", there were 8 unimproved patients, 22 in identical condition and 187 surgically-improved patients. The mean MCID for all methods (anchor method and distribution) was 10 [7-13] for Oxford-12, 12 [12-12] for KOOS Symptom, 14 [12-17] for KOOS Pain, 12 [11-14] for KOOS Function, 14 [12-16] for KOOS Sport, 15 [15-16] for KOOS Quality of Life (QOL), 11 [10-12] for KOOS 12, 15 [12-18] for KOOS 12 Pa in. 12 [12-13] for KOOS 12 Function, 15 [15-15] for KOOS 12 QOL, 14 [13-14] for KOOS Physical Function Short-form (PS) and 14 [13-16] for KOOS Joint Replacement (JR). DISCUSSION: The MCID for the Oxford-12, KOOS and its derivatives scores in a French population is comparable to that observed in other populations in the literature. LEVEL OF EVIDENCE: IV; prospective study without control group.

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.

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.

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.

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.

Cementless metal-on-metal versus ceramic-on-polyethylene hip arthroplasty in under-50 year-olds with 20 to 22 years' follow-up: Was it a good idea to abandon the small-diameter metal-on-metal bearing?

In 2005 and 2011, we reported results for a comparative study of two types of 28-mm bearing (metal-on-metal (MoM) and ceramic-on-polyethylene (CoP) in active patients with respectively 5 and 12 years' follow-up. The present report is an update at a mean 20 years' follow-up, addressing 2 issues: (1) implant survival at a mean 20 years; and (2) long-term complications with the metal-on-metal bearing. Twenty-eight millimeters MoM bearings show good survival at 20 years in young active subjects. Two groups of cementless hip prostheses were compared: Metasul™ 28mm MoM versus 28mm CoP. The MoM group comprised 30 patients (39 hips), with a mean age of 40±6.7 years [range, 22.6-49 years], and the CoP group comprised 32 patients (39 hips), with a mean age of 40.5±8.7 years [range, 15-50 years]. The groups were matched in 2005 for age, activity level and preoperative Harris score. At a mean 20±5.3 years' follow-up [range, 5-23 years], in the MoM group 2 hips (5%) showed limited non-progressive acetabular osteolysis, not requiring revision surgery; in the CoP group, there were 21 revision procedures (54%), including 15 for polyethylene wear. In the MoM group, the median total blood cobalt concentration was 1.03g/L [range, 0.3-3.5] and the median chromium concentration was 1.07g/L [range, 0.3-3.2]. Twenty-year all-cause survival was 100% in the MoM group, and 46% (95% CI, 37-59%) in the CoP group (p<0.0001). At long-term follow-up, MoM implants showed better survival than CoP implants in a young active population. Level of evidence: III, matched case series.

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.

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.

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.

Hip resurfacing for small-sized osteonecrosis: 73 cases at a median 8years' follow-up.

INTRODUCTION: Total hip resurfacing arthroplasty (THRA) is an alternative to conventional total hip replacement (THR) in young patients with osteonecrosis of the femoral head. Series have been small, without criteria regarding extent of necrosis, thus vitiating results. We therefore conducted a retrospective assessment of THRA for small necrosis, to determine (1) implant survival, (2) functional scores, and (3) systemic chromium, cobalt and titanium ion concentrations. HYPOTHESIS: The study hypothesis was that the revision rate is low, meeting the National Institute for Health and Care Excellence (NICE) criterion of<0.5% revision per year. MATERIAL AND METHOD: A single-center single-surgeon retrospective study included 62 patients, for 73 RTHAs, with a mean age of 45.6years (range: 23-68years) presenting Ficat stage 3 or 4 osteonecrosis of the femoral head with<330° total Kerboul angle (frontal+lateral angles) on simple preoperative X-ray. Study data comprised implant survival and preoperative and last follow-up functional scores (Postel-Merle-d'Aubigné, Oxford-12, Harris, and Devane) and titanium, chromium and cobalt blood concentrations. Necrosis size was assessed on preoperative Kerboul angle. RESULTS: At a median 8years' follow-up (IQR: 5.9-9.3years), implant survival was 98.6% (95% CI: 97.22-99.98%). Only 1 implant was exchanged, for femoral loosening. Three other patients underwent revision surgery: 2 cases of lavage for infection, and 1 muscle hernia repair. Postel-Merle-d'Aubigné, Oxford-12 and Harris functional scores and Devane activity scores were significantly improved at follow-up, by a median +5 (IQR: 5 to 7), -26 (IQR: -29 to -23), +55 (IQR: 49 to 61) and +1 (IQR: 1 to 2), respectively (all p<0.001). Ion concentrations at last follow-up for titanium, chromium and cobalt were respectively 4.0µg/L (range: 3.6-4.1), 1.1µg/L (range: 0.8-1.9) and 1.1µg/L (range: 0.6-1.8). CONCLUSION: THRA is a useful option in the long-term for young patients with osteonecrosis with Kerboul angle<330°. LEVEL OF EVIDENCE: IV, retrospective study.