Pull-out strength of four tibial fixation devices used in anterior cruciate ligament reconstruction

International audienceIntroduction: In reconstructions of the anterior cruciate ligament (ACL), tibial fixation can be the weak point in the assembly during the early postoperative period. The present study sought to compare pull-out strength between four tibial fixation systems used in ACL reconstruction.Hypothesis: The study hypothesis was that all four devices show ≥ 450 N pull-out strength with comparable biomechanical breakage characteristics. Material and methods: An experimental study used a mechanical model to perform axial traction on a synthetic ligament (polypropylene cord folded in four) implanted in an artificial tibia (Sawbones Proximal Tibia # 1116-2: model: normal anatomy; solid foam; size: medium) using four tibial fixation systems: Ligafix ® interference screw (SBM TM); Bio-Intrafix ® (Mitek TM); Translig ® (SBM TM); RIGIDfix ® (SBM TM). For each system, four models were tested using an Instron 5566 ® traction machine, allowing 100 mm/min stretching up to breakage. Study parameters comprised: pull-out strength, maximal whole assembly slippage, stiffness at breaking point, and type of break.Results: Mean pull-out strength was 450 ± 24 N (range, 421–488 N) for Ligafix ® , 415 ± 60 N (327–454 N) for Bio-Intrafix ® , 539 ± 66 N (449–636 N) for RigidFix and 1067 ± 211 N (736–1301 N) for Translig ® , and was significantly greater for Translig ® than for the other devices (p = 0.02), which did not significantly differ from one another. The expected maximal load of 450 N was reached in 100% of cases with Translig ® and RIGIDfix ® and in 50% of cases with Bio-Intrafix ® and Ligafix ®. There were no significant differences regarding stiffness. Ligafix ® showed significantly less slippage than the others (p = 0.006), with breakage caused by the ligament sliding between bone and implant.Discussion: In this in-vitro study, the Translig ® fixation device showed better pull-out strength than the other three devices tested. Type of study and level of evidence: Comparative laboratory study. Level II

Fracture céphalotubérositaire à 3 et 4 fragments déplacée de l'humérus proximal après 70 ans : arthroplastie totale inversée de l'épaule ou traitement fonctionnel

Introduction : L’objectif de notre étude était de comparer chez les patients de 70 ans ou plus avec des fractures de l’humérus proximal déplacées à trois ou quatre fragments, les résultats du traitement chirurgical par arthroplastie totale inversée de l’épaule, au traitement non chirurgical après deux ans de recul.Matériel et Méthodes : 2 groupes étaient constitués, 28 patients dans le groupe arthroplastie et 32 dans le groupe traitement non-chirurgical. Le suivi minimum était de deux ans. Nous avons inclus des patients avec des fractures à 3 ou 4 fragments selon la classification de Neer. Les principaux critères de jugement étaient : le score fonctionnel de Constant-Murley, le score QuickDASH et le subjective shoulder value (SSV). Un score d'autonomie, une évaluation cognitive et un score de douleur ont également été recueillis.Résultats : Il n'y avait pas de différence significative entre les deux groupes en ce qui concerne les caractéristiques cliniques. Le score moyen de Constant-Murley était significativement plus élevé pour le groupe arthroplastie 82,1% vs 76,8% (p = 0,03). Les amplitudes de mouvement étaient toutes plus élevées en faveur du groupe arthroplastie (p <0,02). Il n'y avait pas de différence significative sur le Quick DASH moyen, le SSV pré et postopératoire, le score d’autonomie, le score d'évaluation cognitive et le score de douleur dans les deux groupes au recul final. Le taux de complication était plus élevé pour le groupe arthroplastie (0% vs 7%).Conclusion : Les résultats de l'étude suggèrent que le traitement des fractures de l’extrémité supérieure de l’humérus à 3 ou 4 fragments déplacés chez les patients âgés traité par arthroplastie totale inversée procure de meilleurs résultats fonctionnels que le traitement fonctionnel. Cependant, les différence clinique observées sont relativement faible. Cette solution doit donc être proposée seulement aux patients qui ont une demande fonctionnelle élevée

Every layer of quadriceps tendon’s central and medial portion offers similar tensile properties than Hamstrings or Ilio-Tibial Band Grafts

International audiencePurpose: The aim of our cadaveric study was to compare the mechanical properties of different parts of the quadriceps' tendon in a load to failure analysis as compared to three other, and most common types of grafts that are used to perform ligament's reconstruction. Methods: Ten fresh-frozen cadavers (5 women, 5 men) were selected from our anatomical department. Mean age at death was 64 years (48-87 years). Tendons were harvested to prepare (1) different quadriceps tendon's specimens: lateral portion (QTlat), medial portion superficial layer (QTMsup) and deep layer (QTMdeep) and central portion superficial (QTCsup) and deep layers (QTCdeep) (2) Patellar Tendon (PT), (3) Gracilis+Semi-Tendinosus specimens (GST). Specimens were stored at − 40°C in a freezing solution. Specimens were securely attached to a dedicated loading platform, measurements were done using a validated software. Load to failure testing was then carried out. Young's Elastic moduli, ultimate Stress (MPa) and Deformation (%) were analysed. Results: The elastic moduli of the PT was significantly higher than all other grafts, all medial and central QT layers (superficial and deep) were significantly higher than its lateral part (QTlat). In terms of Ultimate Stress, all grafts were significantly greater than QTlat, PT and GST were significantly superior to QT central portions and to ITB but there did not differ with the medial portion of QT. ITB ultimate stress values were significantly higher than QTlat. The ultimate deformations of all grafts were similar. Conclusions: This study provides reference values in in order to characterize different parts of the QT that presents anatomically and Mechanically with complex characteristics. Every Layer of Quadriceps Tendon's Central and Medial Portion Offered Similar Mechanical Properties than Two Strand Hamstrings or Ilio-Tibial Band

Three- and four-part displaced proximal humeral fractures in patients older than 70 years: reverse shoulder arthroplasty or nonsurgical treatment?

International audienceBackground: The objective of our study was to evaluate the results of surgical treatment by reverse shoulder arthroplasty (RSA) compared with nonsurgical treatment after 2 years of follow-up in patients aged 70 years or older with displaced 3-part or 4-part proximal humeral fractures. Methods: Two groups were formed: the RSA group (n = 28) and the nonsurgical group (n = 32). Minimum follow-up was 2 years. We included patients with 3-part or 4-part fractures according to the Neer classification. Main outcome measures were the Constant-Murley score, the 11-item version of the Disabilities of the Arm, Shoulder and Hand score, and the Subjective Shoulder Value score. An autonomy score, a cognitive assessment score, and a pain score were also measured. Results: Clinical features in the 2 groups were not significantly different. The Constant-Murley mean score was significantly higher for the RSA group (82.1% vs. 76.8%; P = .03). Amplitudes were all higher in favor of the RSA group (P < .02). There was no significant difference in mean score on the 11-item version of the Disabilities of the Arm, Shoulder and Hand score, the preoperative and postoperative Subjective Shoulder Value score, the autonomy score, the cognitive assessment score, or the pain score in both groups at the last follow-up. The complication rate was higher for the RSA group. Conclusions: These results suggest that RSA treatment of proximal humeral fractures with 3-part or 4-part displaced fragments in elderly patients provides better functional outcomes than does nonsurgical treatment. However, the observed clinical difference was relatively small. This solution must be proposed only to patients who have a significant functional demand. Level of evidence: Level III; Retrospective Cohort Design; Treatment Stud

Determinants of Urine Output Using Advanced Hemodynamic Monitoring in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy

International audienceIntroduction: Low cardiac output and hypovolemia are candidate macrocirculatory mechanisms explanatory of de novo anuria in intensive care unit (ICU) patients undergoing continuous renal replacement therapy (CRRT). We aimed to determine the hemodynamic parameters and CRRT settings associated with the longitudinal course of UO during CRRT. Methods: This is an ancillary analysis of the PRELOAD CRRT observational, single-center study (NCT03139123). Enrolled adult patients had severe acute kidney injury treated with CRRT for less than 24 h and were monitored with a calibrated continuous cardiac output monitoring device. Hemodynamics (including stroke volume index [SVI] and preload-dependence, identified by continuous cardiac index variation during postural maneuvers), net ultrafiltration (UFNET), and UO were reported 4-hourly, over 7 days. Two study groups were defined at inclusion: non-anuric participants if the cumulative 24 h UO at inclusion was ≥0.05 mL kg−1 h−1, and anuric otherwise. Quantitative data were reported by its median [interquartile range]. Results: Forty-two patients (age 68 [58–76] years) were enrolled. At inclusion, 32 patients (76%) were not anuric. During follow-up, UO decreased significantly in non-anuric patients, with 25/32 (78%) progressing to anuria within 19 [10–50] hours. Mean arterial pressure (MAP) and UFNET did not significantly differ between study groups during follow-up, while SVI and preload-dependence were significantly associated with the interaction of study group and time since inclusion. Higher UFNET flow rates were significantly associated with higher systemic vascular resistances and lower cardiac output during follow-up. Multivariate analyses showed that (1) lower UO was significantly associated with lower SVI, lower MAP, and preload-independence; and (2) higher UFNET was significantly associated with lower UO. Conclusions: In ICU patients treated with CRRT, those without anuria showed a rapid loss of diuresis after CRRT initiation. Hemodynamic indicators of renal perfusion and effective volemia were the principal determinants of UO during follow-up, in relation with the hemodynamic impact of UFNET setting

Intravenous thrombolysis and thrombectomy decisions in acute ischemic stroke: An interrater and intrarater agreement study

International audiencePurpose. - We aimed to assess agreement on intravenous tissue-plasminogen activator (IV tPA) and mechanical thrombectomy (MT) management decisions in acute ischemic stroke (AIS) patients. Secondary objectives were to assess agreement on Diffusion-Weighted-Imaging-Alberta-Stroke-Program-EArly-CT-Score (DWI-ASPECTS), and clinicians' willingness to recruit patients in a randomized controlled trial (RCT) comparing medical management with or without MT. Materials and Methods. - Studies assessing agreement of IV tPA and MT were systematically reviewed. An electronic portfolio of 41 AIS patients was sent to randomly selected providers at French stroke centers. Raters were asked 4 questions for each case: (1) What is the DWI-ASPECTS? (2) Would you perform IV tPA? (3) Would you perform MT? (4) Would you include the patient in a RCT comparing standard medical therapy with or without MT? Twenty responders were randomly selected to study intrarater agreement. Agreement was assessed using Fleiss' Kappa statistics. Results. - The review yielded two single center studies involving 2-5 raters, with various results. The electronic survey was answered by 86 physicians (60 vascular neurologists and 26 interventional neuroradiologists). The interrater agreement was moderate for IV tPA treatment decisions (kappa = 0.565 [0.420-0.680]), but only fair for MT (kappa = 0.383 [0.289-0.491]) and for combined treatment decisions (kappa = 0.399 [0.320-0.486]). The intrarater agreement was at least substantial for the majority of raters. The interrater agreement for DWI-ASPECTS was fair (kappa = 0.325 [0.276-0.387]). Physicians were willing to include a mean of 14 +/- 9 patients (33.1% +/- 21.7%) in a RCT. Conclusion. - Disagreements regarding the use of IVtPA or MT in the management of AIS patients remain frequent. Further trials are needed to resolve the numerous areas of uncertainty. (C) 2019 Elsevier Masson SAS. All rights reserved