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

Lower function, quality of life, and survival rate after total knee arthroplasty for posttraumatic arthritis than for primary arthritis

International audienceBackground and purpose - Total knee arthroplasty (TKA) for treatment of end-stage posttraumatic arthritis (PTA) has specific technical difficulties and complications. We compared clinical outcome, postoperative quality of life (QOL), and survivorship after TKA done for PTA with those after TKA performed for primary arthritis (PA). Patients and methods - We retrospectively reviewed patients who were operated on at our institution for PTA between 1998 and 2005 (33 knees), and compared them to a matched group of patients who were operated on for PA during the same period (407 knees). Clinical outcomes and postoperative QOL were compared in the 2 groups using Knee Society score (KSS), range of motion (ROM) of the knee, and the knee osteoarthritis outcomes score (KOOS). Implant survival rate was calculated using Kaplan-Meier analysis. Results - At a mean follow-up of 11 (5-15) years, KSS knee increased from mean 39 (SD 18) to 87 (SD 16) in the PA group (p = 0.003), and from 31 (SD 11) to 77 (SD 15) in the PTA group (p = 0.003). KSS function increased from 55 (12) to 89 (25) in the PA group (p = 0.008) and from 44 (SD 14) to 81 (SD 10) in the PTA group (p = 0.008). Postoperative ROM also improved in both groups, from 83 degrees to 108 degrees in the PTA group (p < 0.001) as opposed to 116 degrees to 127 degrees in the PA group (p = 0.001), with lower results in the PTA group (p < 0.001). KOOS was lower in the PTA group (p < 0.001). The survival rate of TKA at 10 years with an endpoint defined as "any surgery on the operated knee" showed better results in the PA group (99%, CI: 98-100 vs. 79%, CI: 69-89; p < 0.001). Interpretation - Patients and surgeons should be aware that clinical outcome and implant survival after TKA for PTA are lower than after TKA done for P

Total knee arthroplasty after opening– versus closing-wedge high tibial osteotomy. A 135-case series with minimum 5-year follow-up

INTRODUCTION: High tibial osteotomy (HTO) is effective in treating isolated medial osteoarthritis of the knee, but subsequent deterioration is inevitable, and total knee arthroplasty (TKA) is then an option. The present study sought to compare TKA following medial opening-wedge HTO (OW-HTO) versus lateral closing-wedge HTO (CW-HTO) in terms of intraoperative data and clinical results. The study hypothesis was that there is no significant difference in clinical results or complications in TKA following OW-HTO or CW-HTO. MATERIAL AND METHOD: A retrospective multicenter (9 centers) study was conducted for the French Society of Orthopedic Surgery and Traumatology (SoFCOT), including 135 TKAs following HTO (58 OW and 77 CW) at a minimum 5 years' follow-up. Mean interval between HTO and TKA was 134 months and was longer in case of CW-HTO (P<0.0001). Mean age at TKA was 65.4 years and older in case of CW-HTO (P=0.021). Tibial slope was greater in case of OW-HTO (P=0.024). Prior to TKA, 55.7% of patients could walk without canes, 98.4% found stairs difficult or impossible and only 19.1% could manage a walking distance greater than 1000m. Mean flexion was 110°; 54.2% of patients showed frontal knee stability and 87.8% sagittal stability; 60.1% had a mechanical axis in varus, without difference according to OW- or CW-HTO. RESULTS: Hardware was almost systematically removed (in 98.5% of cases): in the same step for OW-HTO (P=0.018) or often in 2 steps for CW-HTO. The primary approach was generally re-used (54.2%), but less frequently in the CW-HTO group (P=0.0004). Lateral or medial ligament release was not associated in respectively 78.2% and 79.7% of cases. The TKA implant was usually without stem (87.2%) and was fitted using a conventional technique (74.4%). At a mean 87 months' follow-up, 78.5% of patients could walk without canes, stairs were still difficult or impossible for 67%, and 74.1% could now walk further than 1000m; mean flexion was 110.5°. Overall, 91.5% of patients showed frontal knee stability and 98.2% sagittal stability, without difference according to OW- or CW-HTO. There were 15 complications within 3 months, more often in the OW-HTO group (12.3%) although not significantly, and with no difference in severity. Late complications comprised loosening (5.5%) and infection (3.6%) and were more frequent in the CW-HTO group (12%) (P<0.05). DISCUSSION: The study hypothesis was partially confirmed. The only technical differences concerned hardware removal, often performed in two steps in case of CW-HTO, and TKA approach, which differed from the primary approach in case of CW-HTO. Clinical results were comparable between OW- and CW-HTO, but late complications were more frequent in the CW-HTO group

Ten-year survival and complications of total knee arthroplasty for osteoarthritis secondary to trauma or surgery: A French multicentre study of 263 patients

BACKGROUND: Previous surgical procedures raise technical challenges in performing total knee arthroplasty (TKA) and may affect TKA outcomes. Survival rates of TKA done after trauma or surgery to the knee have not been accurately determined in large populations. The objectives of this retrospective study in 263 patients with TKA after knee trauma or surgery and a follow-up of 10 years were to assess survival, functional outcomes, and the nature and frequency of complications. HYPOTHESIS: Knee trauma or surgery before TKA increases the risk of complications and decreases implant survival. MATERIAL AND METHODS: Two hundred and sixty-three patients (122 [47%] females and 141 [53%] males) underwent TKA between 2005 and 2009 at nine centres in France. Mean age at surgery was 61 years. The patients had knee osteoarthritis secondary to a fracture (n=66), osteotomy (n=131), or ligament injury (n=66). Mean time from trauma or surgery to TKA was 145 months (range, 72-219 months). RESULTS: Major complications were infection (n=12, 4.5%), skin problems (n=8, 3%), and stiffness (n=8, 3%). Ten-year survival to implant exchange for any reason was 89%±2.8%. Flexion range increased by 2.5°±17° (p=0.02) to a mean of 110° (range, 30° to 140°); extension range increased by 4°±7° (p<0.001) to a mean of -1.19 (range, -20° to 0°). Of the 263 patients, 157 (60%) reported little or no pain at last follow-up. Mean postoperative hip-knee-ankle angle was 179°±3.2° (range, 171°-188°). CONCLUSION: TKA performed after knee injury or surgery carries a risk of specific complications (infection, skin problems, and stiffness) and may have a lower survival rate compared to primary TKA

Actinomadura meyerae osteitis following wound contamination with hay in a woman in France: a case report

<p>Abstract</p> <p>Introduction</p> <p>Mycetoma is a chronic granulomatous infection caused by environmental fungi or bacteria. It affects dermal and subcutaneous tissues, with putative contiguous extension to muscles or bones. While common in tropical and subtropical areas, mycetoma is rare in Europe.</p> <p>Case presentation</p> <p>We describe a case of <it>Actinomadura meyerae </it>osteitis in a 49-year-old Caucasian woman who suffered a tibia open fracture contaminated with hay; to the best of our knowledge the first case of autochthonous <it>A. meyerae </it>infection reported in France. The bacterium was cultivated from a bone biopsy. Following surgical osteosynthesis and six months of treatment with cotrimoxazole, our patient made a full recovery.</p> <p>Conclusion</p> <p>Our case report suggests that <it>A. meyerae </it>is a potential agent of wound infection in farm workers in contact with hay.</p

Abiotrophia defectiva knee prosthesis infection: A case report

<p>Abstract</p> <p>Background</p> <p><it>Abiotrophia </it>species have rarely been implicated in osteoarticular infections. We report one case of an <it>A. defectiva </it>knee prosthesis infection.</p> <p>Case presentation</p> <p>A 71-year-old man of Italian origin presented with pain and swelling of the knee four years after the implantation of a total knee replacement prosthesis. While standard culturing of the synovial fluid resulted in no isolation of microorganisms, the direct inoculation of the synovial fluid into a rich culture medium resulted in the identification of <it>A. defectiva </it>by polymerase chain reaction sequencing. Repeated attempts of culturing microorganisms from blood were negative, and echocardiograms and colonoscopies were unremarkable. High-dose amoxicillin for nine months and a two-stage replacement of the knee prosthesis led to full patient recovery by the time of the 12-month follow-up examination.</p> <p>Conclusions</p> <p>Because <it>Abiotrophia </it>spp. are fastidious microorganisms, it is likely that cases of <it>Abiotrophia </it>orthopedic infection are misdiagnosed as culture-negative infections. Direct inoculation of synovial fluids into rich broth medium and further polymerase chain reaction-based detection of culture-negative synovial fluids are key tests for accurate documentation and detection of these infections.</p

Etude comparative du remodelage osseux autour de cotyles non cimentés en Tantale ou recouverts d'hydroxyapatite

L intégration osseuse d une pièce cotyloïdienne d une arthroplastie totale de hanche sans ciment demeure problématique. Nous rapportons les résultats précoces radiographiques et densitométriques d un cotyle en tantale monobloc. Matériel et méthode Il s agit d une étude monocentrique rétrospective portant sur 82 patients. Quarante-deux patients ont été opérés avec mise en place d un cotyle en Tantale (Trabecular Metal , Zimmer, Warsaw, IN = groupe 1), 40 avec mise en place d un cotyle recouvert d hydroxyapatite (Hilock , Symbios, Yverdon, Switzerland = groupe 2). L âge moyen d implantation était de 76 ans. Le recul était de 30 mois en moyenne. Nous avons analysé le positionnement radiographique et son évolution, ainsi que la Densité Minérale Osseuse péri cotyloïdienne dans les 3 zones de De Lee et Charnley. Résultats Nous n avons pas observé de migration ou de descellement sur l ensemble de la série. Quatorze pour cent des cotyles du groupe 1 présentaient des radio clartés. Les DMO périprothétiques retrouvées avec le Tantale étaient comparables aux données de la littérature, significativement plus élevées en zone 1 pour ce groupe. Discussion Les résultats radio-cliniques étaient globalement satisfaisants au recul et comparables aux données de la littérature. Les résultats densitométriques du groupe 1 montrent une bonne minéralisation osseuse en zone portante, donc un transfert satisfaisant des contraintes à l anneau pelvien. Un composant en Tantale semble comparable au recul à un cotyle métal-back classique, tout en limitant le stress-shielding péri acétabulaire.AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Chirurgie assistée par ordinateur pour le positionnement de l'implant acétabulaire dans l'arthroplastie totale de hanche

Background: Acetabular component malpositioning during hip arthroplasty increases the risk of dislocation, reduces range of motion and can be responsible for early wear and loosening. The purpose of this study was to compare computer assisted acetabular component insertion versus free-hand placement. Methods: A controlled randomized matched prospective study was performed in two groups of 30 patients. In the first group, cup positioning was assisted by an imageless computer assisted orthopaedics system, based on Bone Morphing (CAOS+ group). In the control group, a free-hand cup placement was performed (CAOS- group). All the patients were operated by the same surgeon through an anterolateral approach. Cup anteversion and abduction angles were measured on three-dimensional CT-scan reconstruction postoperatively for each patient by an independent observer with special cup evaluation software. Results: There were 16 males and 14 females in each group, the mean age was 62 years (24-80) and mean Body Mass Index was 25. Mean additional time of the CAOS procedure was 12 minutes (8-20). There were no statistical differences between the CAOS+ group and the CAOS- group regarding means of the abduction and anteversion angles but a significant heterogeneity of variances, with the lowest variations in the CAOS+ group. Conclusions: This study has shown the accuracy of cup positioning using a CT-free navigation system.INTRODUCTION : Les malpositions de l'implant acétabulaire dans les prothèses totales de hanche peuvent être source de luxations, de limitation des amplitudes articulaires et d'usure précoce des implants. L'objectif de notre étude était de comparer le positionnement acétabulaire après chirurgie assistée par ordinateur par rapport à une technique conventionnelle . MATERIEL ET METHODE : La navigation du composant acétabulaire était effectuée grâce à un logiciel sans image pré-opératoire basée sur le Bone-Morphing®. Nous avons réalisé une étude prospective randomisée incluant deux groupes de 30 patients. Dans le premier groupe, issu de la randomisation, la mise en place de l'implant acétabulaire était effectuée avec navigation (CAO+). Dans le deuxième groupe apparié, l'implant acétabulaire était posé de manière conventionnelle (CAO-). Toutes les interventions ont été pratiquées par le même opérateur par voie antéro-latérale de Watson-Jones. L'implant acétabulaire était dans tous les cas un cotyle hémisphérique non cimenté. L'inclinaison et l'antéversion post-opératoire étaient analysées par un observateur indépendant sur reconstructions tridimensionnelles scannographiques. RESULTATS : Chaque groupe comprenait 16 hommes et 14 femmes. La moyenne d'âge était de 62 ans (24-80) et le BMI moyen de 25. Le temps additionnel moyen du à la navigation était de 12 minutes (8-20). Les moyennes d'antéversion et d'inclinaison étaient statistiquement comparables dans les groupes CAO+ et CAO-, cependant l'écart-type était statistiquement plus faible dans le groupe CAO+ pour l'antéversion et l'inclinaison. DISCUSSION : Les résultats de notre série montrent que l'utilisation d'un système de navigation sans image dans les prothèses totales de hanches est fiable et permet l'optimisation de la pose de l'implant acétabulaire.AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Evaluation densitométrique, scannographique et histologique de l'os spongieux fémoral avant et après prothèse totale de hanche sur mesure non cimentée

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF