Neither significant osteoarthritic changes nor deteriorating subjective outcomes occur after hybrid fixation of osteochondritis dissecans in the young adult.

PURPOSE: The goal of the fixation of painful osteochondritis dissecans of the femoral condyles in adults is to integrate the osteochondral fragment and thus achieve a normal hyaline cartilaginous coverage. The addition of a biological process to primary fixation may result in improved fragment integration (hybrid fixation). Osteochondral plugs may fulfil this role. The aim of this study was to evaluate long-term clinical and radiological results after hybrid fixation of unstable osteochondritis dissecans. The hypothesis was that the rate of secondary osteoarthritis would be low. METHODS: Nine patients treated by hybrid fixation were retrospectively reviewed at a median follow-up of 10.1 years (range 7-14). The median age at surgery was 21 (range 17-28). Six of them were evaluated as ICRS grade II and three, as ICRS grade III. The mean surface of the lesion was 4.5 cm2. All patients were followed up clinically (IKDC, KOOS, Lysholm) and radiologically [Kellgren-Lawrence score (KL)]. RESULTS: During arthroscopic assessment at the time of screw removal (3 months after surgery), the fragments were stable, and autograft plugs were all well integrated. At the most recent follow-up visit, the median IKDC score was 85.8 (range 51.72-100), the KOOS score was 87.7 (52.4-100), and the Lysholm scale score was 89.8 (77-100). In 7 out of 9 patients, radiographs showed a joint space KL grade of 0 or 1. CONCLUSION: Hybrid fixation for treating osteochondritis dissecans lesions of the femoral condyles using mechanical and biological fixation provides healing of the osteochondral fragments with good long-term outcomes. No significant osteoarthritic change was seen with this technique at a mid-term follow-up. LEVEL OF EVIDENCE: IV-case series.

Revealing potential bridge vectors for BTV and SBV: a study on Culicoides blood feeding preferences in natural ecosystems in Spain.

Several species of Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens, such as the bluetongue (BTV) and Schmallenberg (SBV) viruses, which cause important diseases in domestic and wild ruminants. As wild ruminants can contribute to overwintering and epizootics of both diseases, knowledge of the host-feeding behaviour of Culicoides in natural ecosystems is important to better understand their epidemiology. Blood-engorged Culicoides females trapped in natural areas inhabited by different wild ruminant species were genetically analysed to identify host species. The origin of bloodmeals was identified in 114 females of 14 species of Culicoides. A total of 104 (91.1%) Culicoides fed on mammals and 10 (8.9%) on birds. The most abundant host identified was red deer (66.7%), followed by humans (13%) and fallow deer (6.1%). Eleven of the 14 species of Culicoides fed exclusively on mammalian hosts. Among them, five are mammalophilic species considered to be important BTV and/or SBV vectors. The results of the present study confirm that Culicoides imicola, Culicoides obsoletus, Culicoides scoticus, Culicoides pulicaris and Culicoides punctatus fed on wild ruminants, and therefore support the hypothesis that these species can act as bridge vectors by facilitating the circulation of pathogens between wild and domestic ruminant communities.

Experimental study of the susceptibility of a European Aedes albopictus strain to dengue virus under a simulated Mediterranean temperature regime.

Dengue virus (DENV) has re-emerged in Europe driven by the geographic expansion of the mosquito species Aedes albopictus and Aedes aegypti (Diptera: Culicidae) and the introduction of the virus by viraemic travellers. In the present study, the vector competence (VC) of Ae. albopictus collected in Catalonia (northeast Spain) was evaluated for two different DENV strains, DENV-1 and DENV-2, the serotypes responsible for all outbreaks of dengue that have occurred in Europe. Mosquitoes were reared under environmental conditions mimicking the mean temperature and humidity recorded in July on the Mediterranean coast of Catalonia. Mosquitoes were fed on an artificial infectious bloodmeal and, at 14 days post-exposure, infection, disseminated infection and transmission rates (IR, DIR, TR) and transmission efficiency (TE) were determined by testing the virus in the body, legs and saliva. The tested Ae. albopictus strain was found to be susceptible to both DENV-1 and DENV-2 and to be able to transmit DENV-1. This is the first time that the VC of Ae. albopictus for DENV has been tested in Europe in this specific context (i.e. mimicking the Mediterranean temperature and humidity recorded in Catalonia in July). This study confirms the potential of Ae. albopictus to start autochthonous DENV transmission cycles in the Mediterranean basin.

Rift Valley fever virus and European mosquitoes: vector competence of Culex pipiens and Stegomyia albopicta (= Aedes albopictus).

Rift Valley fever (RVF) is a mosquito-borne disease caused by the Rift Valley fever virus (RVFV). Rift Valley fever affects a large number of species, including human, and has severe impact on public health and the economy, especially in African countries. The present study examined the vector competence of three different European mosquito species, Culex pipiens (Linnaeus, 1758) form molestus (Diptera: Culicidae), Culex pipiens hybrid form and Stegomyia albopicta (= Aedes albopictus) (Skuse, 1894) (Diptera: Culicidae). Mosquitoes were artificially fed with blood containing RVFV. Infection, disseminated infection and transmission efficiency were evaluated. This is the first study to assess the transmission efficiency of European mosquito species using a virulent RVFV strain. The virus disseminated in Cx. pipiens hybrid form and in S. albopicta. Moreover, infectious viral particles were isolated from saliva of both species, showing their RVFV transmission capacity. The presence of competent Cx. pipiens and S. albopicta in Spain indicates that an autochthonous outbreak of RVF may occur if the virus is introduced. These findings provide information that will help health authorities to set up efficient entomological surveillance and RVFV vector control programmes.

Clinical outcomes after multiligament injured knees: medial versus lateral reconstructions.

PURPOSE: The purpose of this study was to analyse the clinical outcomes of multiligament injured knees with respect to the medial collateral ligament and posteromedial corner (PMC) repair or reconstruction versus the posterolateral corner (PLC) reconstruction in patients operated according to a codified surgical protocol. METHODS: Patients were divided into two groups depending on whether PMC or PLC was injured. Cruciate ligaments as well as PMC or PLC were reconstructed/repaired in a one-stage procedure. At minimum of 1-year follow-up, objective and subjective International Knee Documentation Committee (IKDC) forms, Lysholm score and sports activity level were recorded. RESULTS: Thirty-nine patients with a median follow-up time of 57 months (range 12-129) were reviewed. No significant difference was found for functional scores between acute PMC and PLC subgroups. In Group PLC, subjective outcomes tend to be better in the acute than in chronic reconstruction subgroup. CONCLUSIONS: A one-stage protocol with early surgery rather than delayed reconstruction produced better clinical outcomes whatever the injured collateral ligament, medial or lateral. In the future, early and chronic reconstructions as well as each injury pattern should be considered as separate entities in studies on multiple ligament injured knees to reach a better level of evidence. LEVEL OF EVIDENCE: IV.

Culex pipiens and Stegomyia albopicta (= Aedes albopictus) populations as vectors for lineage 1 and 2 West Nile virus in Europe.

The emerging disease West Nile fever is caused by West Nile virus (WNV), one of the most widespread arboviruses. This study represents the first test of the vectorial competence of European Culex pipiens Linnaeus 1758 and Stegomyia albopicta (= Aedes albopictus) (both: Diptera: Culicidae) populations for lineage 1 and 2 WNV isolated in Europe. Culex pipiens and S. albopicta populations were susceptible to WNV infection, had disseminated infection, and were capable of transmitting both WNV lineages. This is the first WNV competence assay to maintain mosquito specimens under environmental conditions mimicking the field (day/night) conditions associated with the period of maximum expected WNV activity. The importance of environmental conditions is discussed and the issue of how previous experiments conducted in fixed high temperatures may have overestimated WNV vector competence results with respect to natural environmental conditions is analysed. The information presented should be useful to policymakers and public health authorities for establishing effective WNV surveillance and vector control programmes. This would improve preparedness to prevent future outbreaks.

Abnormal rate of intraoperative and postoperative implant positioning outliers using "MRI-based patient-specific" compared to "computer assisted" instrumentation in total knee replacement.

PURPOSE: The aim of this study was to analyze first intraoperative alignment and reason to abandon the use of patient-specific instrumentation using intraoperative CAS measurement, secondly assess by postoperative CT analysis if CI, based on preoperative 3D-MRI data, improved postoperative component positioning (including femoral rotation) and lower limb alignment as compared with results obtained with CAS. METHODS: In this randomized controlled trial, 80 consecutive patients scheduled to undergo TKA were enrolled. Eligible knees were randomized to the group of PSI-TKAs (n = 40) or to the group of CAS-TKAs (n = 40). In the CAS group, CAS determined and controlled cutting block positioning in each plane. In the PSI group, CAS allowed to measure adequacy of intraoperative alignment including femoral component rotation. At 3 months after surgery, implants position were measured and analyzed with full-weight bearing plain radiographs and CT scan. RESULTS: Intraoperatively, there was a significant difference concerning Sagittal Femoral mechanical, Frontal tibial mechanical angle and tibial slope between the two groups (respectively p = 0.01, p = 0.02, p = 0.046). Custom instrumentation was abandoned intraoperatively in seven knees (17.5 %). Abnormal tibial cuts were responsible of the abandon in three out of seven cases, femoral cut in 1/7 and dual abnormalities in 3/7. Postoperatively, tibial slope outliers percentage was higher in the patient specific instrumentation group with six patients (18.18 %) versus one patient (2.5 %) in the CAS group (p = 0.041). CONCLUSION: Patient specific instrumentation was associated with an important number of hazardous cut and a higher rate of outliers in our series and thus should be used with caution as related to. This study is the first to our acknowledgement to compare intra-operative ancillary and implant positioning of PSI-TKA and CAS-TKA. High rate of malposition are sustained by our findings, as such PSI-TKA should be used with caution, by surgeons capable to switch to conventional instrumentation intra-operatively. LEVEL OF EVIDENCE: Randomized control trial, Level I.

[Compensation of unforeseeable medical complications following cosmetic surgery finally made possible by ONIAM]. / L'indemnisation enfin possible par l'ONIAM des aléas thérapeutiques après un acte de chirurgie esthétique.

In the absence of any proven medical fault by a plastic surgeon, the patient could not obtain compensation through national solidarity (as stipulated by the Law of March 4th 2002). Indeed ONIAM (France's National Office for Medical Accidents' Compensation) has always rejected any claims on the grounds that cosmetic surgery differs from medical care. Through its judgment of February 5th 2014, France's final Court of Appeals settled the question and considered cosmetic surgery as medical care; in case of serious injuries following unforeseeable medical complications, the patient may be compensated by ONIAM, as with any other medical act. This jurisprudence will certainly result in medical liability insurers be no longer those only responsible for compensation of injuries following cosmetic surgery. Plastic surgeons' insurance premiums should logically become cheaper.

Hippocampal abnormalities and age in chronic schizophrenia: morphometric study across the adult lifespan.

BACKGROUND: Hippocampal abnormalities have been demonstrated in schizophrenia. It is unclear whether these abnormalities worsen with age, and whether they affect cognition and function. AIMS: To determine whether hippocampal abnormalities in chronic schizophrenia are associated with age, cognition and socio-occupational function. METHOD: Using 3 T magnetic resonance imaging we scanned 100 persons aged 19-82 years: 51 were out-patients with stable schizophrenia at least 2 years after diagnosis and 49 were healthy volunteers matched for age and gender. Automated analysis was used to determine hippocampal volume and shape. RESULTS: There were differential effects of age in the schizophrenia and control samples on total hippocampal volume (group × age interaction: F(1,95) = 6.57, P = 0.012), with steeper age-related reduction in the schizophrenia group. Three-dimensional shape analysis located the age-related deformations predominantly in the mid-body of the hippocampus. In the schizophrenia group similar patterns of morphometric abnormalities were correlated with impaired cognition and poorer socio-occupational function. CONCLUSIONS: Hippocampal abnormalities are associated with age in people with chronic schizophrenia, with a steeper decline than in healthy individuals. These abnormalities are associated with cognitive and functional deficits, suggesting that hippocampal morphometry may be a biomarker for cognitive decline in older patients with schizophrenia.

[Faulty implants: the court of appeal has ruled surgeon's responsibility]. / Prothèse défectueuse : la responsabilité du chirurgien écartée par la Cour de cassation.

It is in this atmosphere fuelled by the recent scandal of the PIP implants that the final court of appeal has given a judgment on July 12, 2012 which reorients the debate. While patients seeked a shared responsibility between the provider of the implants and the surgeon, in this case of faulty testicular implants, the final court of appeal just ruled out the responsibility of the surgeon. But this jurisprudence can only be applied to private law, i.e. for private healthcare whereas lawsuits filed against public hospitals depend on a different legal liability system.

Survey of practices in surgical management of trapeziometacarpal osteoarthritis in France in 2020.

The purpose of this study was to obtain an overview of French surgical practices for treating trapeziometacarpal osteoarthritis in 2020. An online survey was sent to 64 French hand surgeons: 32 authors of articles on carpometacarpal osteoarthritis of the thumb and 32 other surgeons randomly selected from the membership of the French Society of Hand Surgery (SFCM). The questions concerned demographic data, surgical practice, operative indications, choices for revision surgery, and eight clinical cases. The response rate was 56.2%. The most popular technique was trapeziometacarpal replacement (63.9%). During the previous 5 years, 31.6% of respondents had changed their practices, 69.2% of whom had adopted total joint replacement. Total trapeziectomy with ligamentoplasty and interposition was the second most frequent method. Most surgeons (77.8%) implemented medical treatment for 6 months to 1 year before resorting to surgery. In the clinical cases, agreement between surgeons was very low, with an overall inter-rater concordance coefficient of 0.182. Except for two cases (a young manual worker and a patient with a flattened trapezium) where no technique was significantly preferred, trapeziometacarpal replacement was chosen by a majority of respondents (p < 0.001). It was the most frequently performed surgical technique in France in 2020. However, there is no real consensus on choice of technique, which reflects the absence of guidelines.

Brachytherapy: An emblematic example of extreme hypofractionated regimen.

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3Gy), then ultra (dose/fraction: 5.2 to 6.1Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20Gy/fraction), the use of a single fraction of 19 to 23Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.

A model of guided cell self-organization for rapid and spontaneous formation of functional vessels.

Most achievements to engineer blood vessels are based on multiple-step manipulations such as manual sheet rolling or sequential cell seeding followed by scaffold degradation. Here, we propose a one-step strategy using a microfluidic coextrusion device to produce mature functional blood vessels. A hollow alginate hydrogel tube is internally coated with extracellular matrix to direct the self-assembly of a mixture of endothelial cells (ECs) and smooth muscle cells (SMCs). The resulting vascular structure has the correct configuration of lumen, an inner lining of ECs, and outer sheath of SMCs. These "vesseloids" reach homeostasis within a day and exhibit the following properties expected for functional vessels (i) quiescence, (ii) perfusability, and (iii) contractility in response to vasoconstrictor agents. Together, these findings provide an original and simple strategy to generate functional artificial vessels and pave the way for further developments in vascular graft and tissue engineering and for deciphering the angiogenesis process.

[Quality of tibial cementing in total knee arthroplasty: one or two phase cementing of the tibial and femoral implants]. / Qualité du scellement tibial dans les arthroplasties totales du genou: scellement en un ou deux temps des pièces tibiale et fémorale Etude prospective comparative.

PURPOSE OF THE STUDY: When implanting a total knee prosthesis, the tibial component can be cemented either independently in the flexion position by maintaining an axial force on the implant, or simultaneously in extension by applying a compression force on both the tibial and femoral implants after reducing the prosthesis. The purpose of this study was to determine whether the quality of the cementing depends on the method used: independently in the flexion position, or simultaneously in the extension position. MATERIAL AND METHODS: This was a prospective comparative study between two groups of 20 patients assigned alternatively to one of two study arms: Group 2 with a tibial implant cemented independently and Group 1 with a tibial implant cemented simultaneously with the femoral implant. The cancellous surfaces were prepared by irrigation and gravity flow wash-out. Aspiration of the cancellous section surface was maintained until the radio-opaque cement with standard viscosity (CMW3) was inserted. The penetration of cement into the cancellous bone was noted by zone on the postoperative radiographs (seven days and one month). Implant position, presence of early lucent lines and cement debris were noted. Radiographs were taken under fluoroscopic guidance in order to obtain the best image of the joint space and the tibial plateau. RESULTS: Cement penetration into the tibial plateau was significantly more pronounced in Group 2 for zones 1, 2 (p<0.01) and 3 (p<0.05) on the above proof view. Early translucent lines were noted in 15 of 20 knees in Group 1 (p<0.01). Cement debris and microfractures were noted in five knees in Group 1 (one in Group 2). The position of the implants was not affected by the method used for cementing. CONCLUSION: This study demonstrates the theoretical and radiographic interest of cementing the tibial piece independently with the knee in the flexion position for total knee replacement. It is important to apply sustained pressure to obtain good quality cement-bone interpenetration.

Meniscal repair: Technique.

Meniscal repair aims to achieve meniscal healing, avoiding the adverse effects of meniscectomy. Longitudinal vertical tears in a vascularized area are the reference indication. The technique generally uses hybrid all-inside implants. The outside-in technique has other indications in more anterior tears. Healing has been demonstrated on CT-arthrography and arthroscopy. Specific techniques have been developed for other pathological situations. Posterior meniscosynovial lesions in a context of chronic anterior laxity are identified by exploration of the posterior compartment, and fixed by all-inside hook suture. Horizontal lesions in young athletes can be treated by open meniscal suture. Radial tears, when deep, can be repaired. Root tears, when traumatic, can be treated by transosseous pullout reinsertion.

Meniscal sizing before allograft: Comparison of three imaging techniques.

BACKGROUND: Accuracy of meniscal sizing is an important issue before allograft transplantation. To date, there is no consensus on the best imaging method. The purpose of this study was to compare plain radiographs, magnetic resonance imaging (MRI) and computed tomography (CT) arthrography in the assessment of meniscal size. We hypothesized that MRI and CT arthrography had better correlations than plain radiographs. METHODS: All patients operated on by meniscal allograft between January 2005 and May 2015 were screened. Among them, 32 patients had both preoperative radiographs, MRI and CT arthrography of the affected knee. The meniscal dimensions were evaluated, blindly and randomly, using three imaging methods. A correlation analysis between each technique was made. For radiographic methods, an additional comparison was made between original Pollard's method and the modified method (Yoon). Bone dimensions (tibial metaphysis) were also collected, using radiographs and MRI, in order to build new equations allowing determination of meniscal dimensions from those bone measurements. RESULTS: The radiographic methods offered satisfying evaluations of the meniscal dimensions in the sagittal plane, without significant difference when compared with CT arthrography or MRI. In the frontal plane, the radiograph methods were less effective. With new equations, allowing determination of meniscal dimensions from tibial plateau dimensions, the mean correlation coefficient was 0.39 (0.14-0.71). CONCLUSIONS: The correlation between radiographic methods and MRI depended on which parameter (frontal or sagittal) was measured. Thus, we proposed a new method for sizing of meniscus, easily measurable from bony landmarks, aiming to improve the accuracy of graft selection.

Complications and cost of single-stage vs. two-stage bilateral unicompartmental knee arthroplasty: A case-control study.

BACKGROUND: Single-stage bilateral knee arthroplasty, even when unicompartmental, remains controversial, chiefly due to the risk of peri-operative complications. The primary objective of this study was to compare the short-term complication rate and cost of single- vs. two-stage bilateral unicompartmental knee arthroplasty (UCA). The secondary objective was to compare total hospital stay lengths and motion-range recovery. HYPOTHESIS: Single-stage bilateral UCA is a cost-saving alternative that is not associated with higher complication rates compared to two-stage bilateral UCA. MATERIAL AND METHOD: This single-centre retrospective comparative study included 70 patients of any age managed between 2010 and 2016. Among them, 44 (88 UKAs) had single-stage surgery (1S group) and 26 (52 UCAs) two-stage surgery (2S group). The two groups were comparable for age, body mass index, gender distribution, compartment replaced, ASA score, and Charlson comorbidity index. The following were evaluated: operative time, haemoglobin level before and after surgery, major and minor complication rates, motion-range recovery, and the radiographic hip-knee-ankle (HKA) angle. Costs were estimated based on the standard codes assigned to the procedures by the national statutory health insurance system (GHM 08C24 for knee arthroplasty to treat knee osteoarthritis and NFKA006 for unicompartmental tibio-femoral or femoro-patellar arthroplasty), modulated according to the concomitant diagnoses. RESULTS: No differences were found for the haemoglobin level change, time to motion-range recovery, or HKA angle. The complication rates per patient were not significantly different between the groups: major complications, 9.1% (n=4) in the 1S group and 15.4% (n=4) in the 2S group (p=1.00); minor complications, 4.5% (n=2) in the 1S group and 3.8% (n=1) in the 2S group (p=1.00). Cost of the total hospital stay was significantly higher in the 2S group than in the 1S group (11,766.7€) and 5626.4€, respectively; p<0.001). Mean total hospital stay duration per patient was 6.7 days with single-stage surgery and 13.4 days with two-stage surgery. DISCUSSION: Single-stage bilateral UCA is not associated with a higher rate of peri-operative complications compared to the two-stage alternative and is substantially less costly. Financial incentives from the healthcare authorities are warranted to increase the use of the single-stage procedure. LEVEL OF EVIDENCE: III, case-control study.

Opening-wedge high tibial osteotomy without bone grafting in severe varus osteoarthritic knee. Rate and risk factors of non-union in 41 cases.

INTRODUCTION: Using locking plates in opening-wedge high tibial osteotomy (OWHTO) via a medial opening theoretically allows early weight-bearing without need for bone or bone-substitute grafting. It incurs a risk of non-consolidation in case of large correction (>10°), although rates and risk factors of non-union are not known. The present retrospective study compared OWHTO with correction <10° versus >10°, with a view to determining: (1) complications rates (non-union) according to degree of correction, and (2) risk factors for such complications. HYPOTHESIS: OWHTO with correction greater than 10° without graft shows normal consolidation and allows early weight-bearing. MATERIAL AND METHOD: Forty-one patients treated by OWHTO for medial osteoarthritis of the knee between January 2101 and November 2015 were included in a retrospective study. HKA angle was assessed by long-leg axis radiographs, preoperatively and at 3 months. Clinical and radiological follow-up at 6 weeks, 3 months and 6 months assessed consolidation in terms of >40% filling of the osteotomy site. Partial (contact) weight-bearing was allowed from the first postoperative day, with full weight-bearing at 6 weeks. RESULTS: Mean patient age was 59±5 years. Mean body-mass index (BMI) was 30.3±5.2; 17 patients (41.5%) had BMI >30. Mean initial HKA angle was 173.5°±3° (range, 167-178°) and mean correction was 10.7°±2.7° (range, 5-15°). There were 27 corrections of 10° or more, and 14 less than 10°. At 3 months, mean HKA was 182.9°±2.5° (range, 178-187°). Twelve cases showed lateral tibial cortex fracture after opening. Thirty-six patients (87.8%) showed consolidation, at a mean 5±3 months. Five patients showed osteotomy site non-union; in all these cases, the lateral cortex was broken initially (P=0.003); all had BMI >30 (mean, 37.2±3.8; P<0.03); none were smokers. On univariate analysis, lateral tibial cortex fracture (OR=10; 95% CI, (1.59-196.30)), BMI >30 (OR=1.18; 95% CI, (1.03-1.41)) and correction ≥10° (OR=10.50; 95% CI, (2.49-53.86)) were associated with delayed consolidation. On multivariate analysis, only degree of osteotomy was significantly associated with delayed consolidation (OR=11.51; 95% CI, (2.13-95.74)). DISCUSSION/CONCLUSION: Obesity and initial lateral cortex fracture appeared as risk factors for non-consolidation of OWHTO with large correction. Systematic bone or bone-substitute grafting may therefore be considered in this population in case of >10° correction. LEVEL OF EVIDENCE: IV, prospective cohort study.

Anterior tibial laxity using the GNRB® device in healthy knees.

BACKGROUND: GRNB® is a non-radiating power tool that allows the evaluation of the anterior tibial translation. HYPOTHESIS: The pressure exerted by the system against the patella and the body mass index (BMI) could affect the anterior tibial translation when we repeat the measurements in healthy knees. MATERIALS AND METHODS: We retrospectively evaluated the measurements of anterior knee laxity in healthy knees carried out by the GNRB® in 69 consecutive patients who underwent anterior cruciate ligament (ACL) repair in the contralateral knee. Two measurements were carried out, the initial measurements (M1), and then repeated at a mean of seven months (M2) (4.9 to 13months). RESULTS: There were 38 women and 31 men with an average age of 31years. In healthy knees, the Mean average anterior translation was 5.4±4mm with an average patellar force of 35.8 at time M1. The average anterior translation was 4.9±4mm with an average patellar force of 47 at time M2. There was a significant difference between the measurements M1 and M2 (P<0.03). The tightening force was significantly different between the two sets of measurements (P<10-7). There was a negative correlation between the pressure applied on the patella and anterior knee laxity (P<0.01). CONCLUSION: The pressure force exerted on the patella during GNRB® affects the measurement of anterior laxity in healthy knees. This raises the problem of the reproducibility of the measurements during repeated examinations at different times.