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Can Plate Osteosynthesis of Periprosthethic Femoral Fractures Cause Cement Mantle Failure Around a Stable Hip Stem? A Biomechanical Analysis

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... Il faut choisir un implant peu encombrant, adapté à la courbure du fémur, permettant la synthèse par câbles ou par vis en s'affranchissant des difficultés liées à la présence de l'implant fémoral. Différentes études biomécaniques montrent qu'il n'y a pas de différence de solidité de montage entre l'utilisation de câbles proximaux ou de vis proximales (27)(28)(29)(30)(31)(32).Il faut au minimum trois câbles ou trois vis bicorticales au-dessus de la fracture et au minimum trois vis bicorticales ou deux vis bicorticales et un câble en dessous de la fracture. Le montage par câblage seul est moins solide, il faut l'associer à l'utilisation de vis en distal pour supprimer les déplacements en translation et en rotation. ...
... De plus, les vis bi corticales ont une meilleure tenue que les vis mono corticales. Le vissage endommagerait pour certains le manteau de ciment ce qui conduirait à une défaillance de la vis à long terme (30,32). Les études montrent aussi que l'amincissement des corticales, les fractures instables ainsi que les fractures descendant en dessous de l'extrémité distale de la prothèse conduisent à des montages moins solides (31). ...
... Publications report several osteosynthesis techniques: by direct or minimally invasive approach, locked or unlocked plate. The results and findings are variable (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Biomechanical studies show that proximal mono cortical and distal bi cortical screw fixations or proximal cerclage and distal bi cortical screw fixations ensure good stabilization in axial compression, lateral compression in 4 points (anterior-posterior and medio-lateral) and in torsion (31)(32)(33). ...
Thesis
Introduction : La fracture péri prothétique du fémur (FPF) est une complication fréquente chez les personnes âgées, souvent dépendantes avec une espérance de vie limitée. Leur prise en charge est difficile et le choix entre ostéosynthèse et changement prothétique est toujours sujet à discussion. A ce jour, il n’existe aucune étude concernant une plaque non verrouillée avec cerclages intégrés et crochet trochantérien pour cette indication. Les objectifs de cette étude étaient d’analyser la consolidation des fractures, le taux de complication et le résultat fonctionnel. Notre hypothèse est que cette technique permet un fort taux de consolidation et un retour à l’état antérieur en terme d’autonomie et de lieu de résidence. Matériels et méthodes : Nous avons réalisé une étude rétrospective multicentrique (Nancy, Metz, Thionville et Remiremont) entre 2010 et 2015. Les critères d’inclusion étaient : patients présentant une FPF de type A et B selon la classification de Vancouver, avec ostéosynthèse par plaque à crochet. L’évaluation a porté sur le délai de consolidation, les complications et les scores de Parker et de Katz en pré et post-opératoire. Etaient considérées comme des complications majeures : décès, pseudarthrose, luxation, infection, faillite de l’ostéosynthèse. Résultats : Quarante-cinq patients satisfaisaient aux critères d’inclusion et ont été évalués au recul moyen de 20 mois (6-72). Toutes les fractures ont consolidé au délai moyen de 7 semaines (6-10), sauf une qui n’a pas fait l’objet d’une reprise chirurgicale en l’absence de retentissement fonctionnel. Un lavage précoce a été réalisé pour un écoulement sur cicatrice à 3 semaines avec une bonne évolution. Le score de Parker a diminué de 6.4 à 4.9 (p=0.03) et le score de Katz de 4.8 à 4.3 (p=0.045). Cinq patients sont décédés dans l’année suivant l’opération. Cinq patients vivant à domicile en pré opératoire ont été institutionnalisés, les autres ont pu retrouver leur maison de retraite ou leur EHPAD. Conclusion : Cette plaque permet une prise en charge rapide et efficace des patients ayant une FPF. Le faible taux de complication et le très bon taux de consolidation nous poussent à utiliser cette plaque même pour les fractures classées B2 ou B3 chez certains patients à l’état général précaire ne pouvant pas tolérer une chirurgie lourde de reprise : âgé, score ASA>3, en perte d’autonomie, score de Katz<4.
... There is little consensus seen on loading protocols; loads to failure was also not consistent across the Table 1 A summary of the specimen preparation and loading protocol in laboratory studies. (Giesinger et al., 2014) studies, an issue that was raised previously. Boundary conditions, magnitudes, and direction of loads applied varied between authors, seen in Table 1. ...
... Distal part of femur is potted in PMMA cement (Lenz et al., 2012a). (Choi et al., 2010;Giesinger et al., 2014;Graham et al., 2015;Griffiths et al., 2015;Gwinner et al., 2015;Konstantinidis et al., 2010;Lochab et al., 2017;Sariyilmaz et al., 2014;Shah et al., 2011). B) No gap (Brand et al., 2014;Frisch et al., 2015;Griffiths et al., 2015;Hoffmann et al., 2014;Konstantinidis et al., 2017;Lehmann et al., 2010;Lenz et al., 2012aLenz et al., , 2012bLenz et al., , 2016aLever et al., 2010;Pletka et al., 2011). ...
... B) No gap (Brand et al., 2014;Frisch et al., 2015;Griffiths et al., 2015;Hoffmann et al., 2014;Konstantinidis et al., 2017;Lehmann et al., 2010;Lenz et al., 2012aLenz et al., , 2012bLenz et al., , 2016aLever et al., 2010;Pletka et al., 2011). C) Fracture gap filled with cement (Giesinger et al., 2014). D) Fracture gap with a wedge-like cut (Gwinner et al., 2015;Wähnert et al., 2014Wähnert et al., , 2017. ...
Article
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Background: Periprosthetic femoral fracture is a severe complication of total hip arthroplasty. A previous review published in 2011 summarised the biomechanical studies regarding periprosthetic femoral fracture and its fixation techniques. Since then, there have been several commercially available fracture plates designed specifically for the treatment of these fractures. However, several clinical studies still report failure of fixation treatments used for these fractures. Methods: The current literature on biomechanical models of periprosthetic femoral fracture fixation since 2010 to present is reviewed. The methodologies involved in the experimental and computational studies of periprosthetic femoral fracture fixation are described and compared with particular focus on the recent developments. Findings: Several issues raised in the previous review paper have been addressed by current studies; such as validating computational results with experimental data. Current experimental studies are more sophisticated in design. Computational studies have been useful in studying fixation methods or conditions (such as bone healing) that are difficult to study in vivo or in vitro. However, a few issues still remain and are highlighted. Interpretation: The increased use of computational studies in investigating periprosthetic femoral fracture fixation techniques has proven valuable. Existing protocols for testing periprosthetic femoral fracture fixation need to be standardised in order to make more direct and conclusive comparisons between studies. A consensus on the 'optimum' treatment method for periprosthetic femoral fracture fixation needs to be achieved.
... The neutralization of torsional forces requires bicortical fixation in both, the proximal and the distal fracture fragment [14]. Up to now, it remains controversial, if screws could be anchored in the cement mantle of cemented stems without damage of its integrity provoking loosening of the stem [28]. The potential of this option has not been investigated in detail jet. ...
... The potential of this option has not been investigated in detail jet. In osteoporotic bone, a screw placement in the cement mantle would enhance screw purchase [28]. ...
Article
Fixation techniques of periprosthetic fractures are far from ideal although the number of this entity is rising. The presence of an intramedullary implant generates its own fracture characteristics since stiffness is altered along the bone shaft and certain implant combinations affect load resistance of the bone. Influencing factors are cement fixation of the implant, intramedullary locking and extramedullary or intramedullary localization of the implant and the cortical thickness of the surrounding bone. Cerclage wires are ideally suited to fix radially displaced fragments around an intramedullary implant but they are susceptible to axial and torsional load. Screws should be added if these forces have to be neutralized. Stability of the screw fixation itself can be enhanced by embracement configuration around the intramedullary implant. Poor bone stock quality, often being present in metaphyseal areas limits screw fixation. Cement augmentation is an attractive option in this field to enhance screw purchase.
... Surgical fixation of periprosthetic femur fractures around a cemented hip arthroplasty often requires screw placement into the cement mantle to optimize fixation. Biomechanical research has offered mixed results regarding the safety of placing screws into the cement [6,10], but clinical outcomes have not previously been reported. In this retrospective cohort study, we compared reoperation and overall complication rates between patients with periprosthetic diaphyseal femur fractures who had screws placed into the cement mantle of their prosthesis (CD) with patients who had screws placed around an uncemented arthroplasty (PF) and found no differences. ...
... Crack formation could be reduced significantly by overdrilling relative to the recommended drill bit, although this unsurprisingly resulted in decreased pull-out strength, and is not a practical clinical recommendation when construct stability is paramount [6]. Kampshoff's results conflicted with a study by Giesinger et al., who found no signs of cement mantle damage when 36 standard 5.0-mm cortical screws were placed bicortically through the cement mantle immediately after drilling in a composite bone model of a Vancouver C periprosthetic fracture [10]. The authors suggest that the drilling process is likely associated with temperatures above the melting point of bone cement [11], which results in local melting around the screw path and screw insertion into soft cement; thus, crack formation may be prevented. ...
Article
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Objective To determine if screw fixation across a cement mantle is safe and effective during plate fixation of well-fixed periprosthetic femur fractures. Design Retrospective cohort study. Setting Academic Level I Trauma Center. Patients Twenty-eight patients with AO/OTA 32A[B1] or 32A[C] periprosthetic femur fractures treated with open reduction and internal plate and screw fixation after cemented or uncemented hip arthroplasty. Intervention Screw placement into the cement mantle during internal fixation. Outcome Measurements Primary outcome was revision arthroplasty for aseptic loosening. Secondary outcomes included radiographic evidence of aseptic loosening, infection, nonunion, implant failure, and overall reoperation rate. Results There were 28 patients who met inclusion criteria. A total of 9 patients had screws placed in the cement mantle while the remaining 19 patients had screws placed around an uncemented stem. At a mean of 3.7-year follow-up, there were no cases of revision arthroplasty or aseptic loosening in either group. There were no significant differences in rates of infection, nonunion, implant failure, or reoperation rate between patients who had screw placement into a cement mantle vs around an uncemented stem. Conclusion Drilling into the cement mantle during fixation of a periprosthetic femur fracture around a well-fixed cemented hip stem appears safe and effective. When possible, surgeons can consider bicortical screws around a cemented stem, given the biomechanical advantages over unicortical screw or cerclage fixation. Larger prospective trials confirming the safety of this technique are warranted prior to routine implementation. Level of Evidence III.
... Of note, the screw placement distally (anteriorly or posteriorly to the prosthesis) is facilitated by multiaxial (30 degrees) placement options. Specialized drills may also be used without risk of compromising the mechanical integrity of the cement mantle, if the reconstruction is cemented [11]. An intraoperative anteroposterior radiograph of the femur was obtained after fixation; fluoroscopic images were not required. ...
Article
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Background Fixation of the greater trochanter with total hip replacement is challenging and associated with short- and long-term complications. Locking plate technology has been used for fixation of other bones and may be applied successfully in trochanteric fixation. The purpose of this retrospective study was to analyze the utility of the use of trochanteric locking plates in total hip arthroplasty (THA) patients. Methods From 2004 to 2014, 32 procedures were performed to fix the greater trochanter in patients with trochanteric fracture, osteotomy, or nonunion in the setting of THA. The median age at the time of surgery was 69 years. This was a primary arthroplasty in 8 of the patients, conversion from prior hip surgery in 5, and a revision in 19. The greater trochanter was fixed with locking plate alone in 15 hips and with the addition of a single cerclage cable in 17 hips. Patients were followed clinically and radiographically until healing occurred. The median duration of radiographic follow-up was 41.6 months (range: 10-112 months). Results Osseous union occurred in 29 (90.6%) of 32 hips. The median Harris hip score was 94 (range 54-100, standard deviation = 10.4) at latest follow-up. Complications included broken hardware in 5 (15.6%) patients, of which 3 underwent subsequent hardware removal. Two additional patients elected hardware removal due to trochanteric pain. Conclusions Locking plate technology is a successful method of fixation of the greater trochanter in patients with THA. Postoperative trochanteric pain and reoperation for hardware-related issues remain a challenge.
... This plate makes the surgical procedure easier, as its anatomical curvature is well-suited to the femur's forward curvature, and the eccentric holes allow for screw placement around the existing femoral stem. In addition, placing bicortical screws around the stem ensure better fixation without altering the cement mantle in patients with a well-cemented stem [35,36]. This plate's main features have been adopted in the current locking plate systems, sometimes with polyaxial screws [20][21][22][23][24]. ...
Article
Periprosthetic femur fracture (PFF) is a serious complication after total hip arthroplasty that can be treated using different internal fixation devices. However, the outcomes with curved non-locking plates with eccentric holes in this indication have not been reported previously. The objectives of this study were to determine: (1) the union rate; (2) the complication rate; (3) autonomy in a group of patients with a Vancouver type B PFF who were treated with this plate. Use of this plate results in a high union rate with minimal mechanical complications. Forty-three patients with a mean age of 79 years±13 (41-98) who had undergone fixation of Vancouver type B PFF with this plate between 2002 and 2007 were included in the study. The time to union and Parker Mobility Score were evaluated. The revision-free survival (all causes) was calculated using Kaplan-Meier analysis. The average follow-up was 42 months±20 (16-90). Union was obtained in all patients in a mean of 2.4 months±0.6 (2-4). One patient had varus malunion of the femur. The Parker Mobility Score decreased from 5.93±1.94 (2-9) to 4.93±1.8 (1-9) (P=0.01). Two patients required a surgical revision: one for an infection after 4.5 years and one for stem loosening. The survival of the femoral stem 5 years after fracture fixation was 83.3%±12.6%. Use of a curved plate with eccentric holes for treating type B PFF led to a high union rate and a low number of fixation-related complications. However, PFF remains a serious complication of hip arthroplasty that is accompanied by high morbidity and mortality rates. Retrospective study, level IV. Copyright © 2015. Published by Elsevier Masson SAS.
... Giesinger et al. conducted another biomechanical study on 17 synthetic femurs and found no cracks in cement mantle after bicortical screw insertion (25). Difference is that they used same diameter drill bit and screw inserted right after the screw size was measured. ...
Article
he goal of our preliminary report is to investigate hip stem stability and intra-operative cement mantle integrity after screw insertion in plate fixation of periprosthetic Vancouver B1 femur fractures. From a cohort of 50 patients with a periprosthetic femur fracture treated in our department from February 2012 until February 2017, we included in our study patients with a periprostethic Vancouver B1 femoral fracture in cemented hip arthroplasty and hemiarthroplasty, operated with ORIF using a 4.5/5.0 LCP Proximal Femoral Hook Plate ® (Synthes, Switzerland) with at least one screw perforating the cement mantle. Anteroposterior and lateral femur views and pelvis X-rays were performed preoperatively. The stability of the hip implant and the cemented mantle integrity was evaluated intra-operatively in a macroscopic way and with a post-operative X-ray in anteroposterior and lateral views. Only 7 patients satisfied the inclusion criteria; no lesion/break of the cement mantle occurred intra-operatively at any step during drilling or screw insertion, also confirmed with C-arm assessment. No cases of stem mobilization were found and cement mantle integrity was maintained in every case. Insertion of screws around a cemented stem for plate fixation in periprosthetic femur fractures Vancouver type B1 could be considered a safe procedure. However, further and more extended studies are necessary for proving additional knowledge at the evaluation of the cement mantle in osteosynthesis procedures.
... Due to the voids of cancellous bone in the osteoporotic femur, the bicortical anchorage of screws in the cortex is essential to achieve biomechanical stability [106]. Bicortical tangential screw placement still carries the risk of the breach of cement mantle integrity and may lead to an early loosening of a cemented hip stem [108] due to cement mantle damage and crack formation. As the risk of a crack decreases with the distance of the screw in relation to the stem screws should be placed outside or at the periphery of the cement [109]. ...
Article
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Purpose of Review Fractures of osteoporotic bone in elderly individuals need special attention. This manuscript reviews the current strategies to provide sufficient fracture fixation stability with a particular focus on fractures that frequently occur in elderly individuals with osteoporosis and require full load-bearing capacity, i.e., pelvis, hip, ankle, and peri-implant fractures. Recent Findings Elderly individuals benefit immensely from immediate mobilization after fracture and thus require stable fracture fixation that allows immediate post-operative weight-bearing. However, osteoporotic bone has decreased holding capacity for metallic implants and is thus associated with a considerable fracture fixation failure rate both short term and long term. Modern implant technologies with dedicated modifications provide sufficient mechanical stability to allow immediate weight-bearing for elderly individuals. Depending on fracture location and fracture severity, various options are available to reinforce or augment standard fracture fixation systems. Summary Correct application of the basic principles of fracture fixation and the use of modern implant technologies enables mechanically stable fracture fixation that allows early weight-bearing and results in timely fracture healing even in patients with osteoporosis.
... The possibility of a cement mantle failure during screw insertion has also been investigated. [53][54][55] The occlusion of the femoral canal (implant/cement mantle), prior reaming, cement exothermic reaction, and pressurization all have a negative impact on the intramedullary blood supply. 56 Further periosteal devascularization during the procedure contributes to further biologic compromise of the local environment. ...
Article
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The Vancouver classification is still a useful tool of communication and stratification of periprosthetic fractures, but besides the three parameters it considers, clinicians should also assess additional factors. Combined advanced trauma and arthroplasty skills must be available in departments managing these complex injuries. Preoperative confirmation of the THA (total hip arthroplasty) stability is sometimes challenging. The most reliable method remains intraoperative assessment during surgical exploration of the hip joint. Certain B1 fractures will benefit from revision surgery, whilst some B2 fractures can be effectively managed with osteosynthesis, especially in frail patients. Less invasive osteosynthesis, balanced plate–bone constructs, composite implant solutions, together with an appropriate reduction of the limb axis, rotation and length are critical for a successful fixation and uneventful fracture healing. Cite this article: EFORT Open Rev 2021;6:955-972. DOI: 10.1302/2058-5241.6.200050
Article
Periprosthetic fractures (PPFs) present unique challenges to orthopaedic surgeons in terms of limited cortical fixation options, poor bone quality, cement mantles, and stress risers introduced from the prosthesis. Various fixation strategies have been used in PPFs including the use of intramedullary nails, locked plates, unicortical locking screws, cerclage wires and cables, double-plating techniques, and allograft struts. Here, we will review the biomechanics of various fixation strategies used in PPFs.
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肿瘤假体置换术是侵袭性或恶性肿瘤切除术后主要的重建方式。综合治疗对骨肿瘤良好控制的前提下,肿瘤假体置换保留了患者肢体和部分功能,提高其生活质量。随着假体使用的广泛,长期随访中其并发症报道逐渐增多。通过对文献回顾性研究,将并发症主要分为两种类型,即肿瘤相关和非肿瘤相关并发症。本研究旨在对并发症进行分析研究。 Tumor prosthesis applies to reconstruction after invasive or malignant neoplasm’s resection. Multidiscipline treatment is known to local and system control. The desirable limb-saving condi-tion leads to more patients undergoing arthroplasty. The use of tumor prosthesis is accessible because of high survival rate. The complications of arthroplasty attach growing attention in the long- term follow-up. There are two types of failure in the retrospective study, tumor-related and non- tumor-related complications. This study is aimed to classify complications and summarize diagnosis and treatment.
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Osteosynthesis of periprosthetic femur fractures by screw fixation around the implanted prosthetic stem is currently regarded as the biomechanically superior option compared with cerclage. The aim of this biomechanical study was damage analysis of the cement mantle after revision screw insertion. A prosthetic stem (Bicontact) was implanted in 20 cadaveric femora in cemented technique. A locking compression plate (Synthes) was then applied to the lateral femur at the level of the prosthetic stem. The method of plate fixation to the femur was assigned randomly to three groups: bicortical non-locking screws, monocortical locking screws, and bicortical locking screws. This was followed by applying a fluctuating axial load (2100 N, 0.5 Hz) for 20,000 cycles. After testing, macroscopic and microscopic evaluations of the cement mantle were conducted. Cracks formed in the cement mantle in 14% of the 80 screw holes. The type of screw (bicortical or monocortical; locking or non-locking) had no significant effect on the number of cracks (p = 0.52). The relationship between manifestation of crack damage and cement mantle thickness was not significant (p = 0.36), whereas the relationship between crack formation and screw position was significant (p = 0.019). Those screws whose circumference was only partially within the cement mantle yielded a significantly lower number of cracks compared with screws positioned completely within the cement mantle or even touching the prosthetic stem. In order to reduce the incidence of crack formation in the cement mantle during plate osteosynthesis of periprosthetic femur fractures, the screws should not be either placed within the cement mantle or make direct contact with the stem.
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Periprosthetic fractures (PPFx) are becoming an increasingly important topic in orthopedics and trauma surgery due to the rising number of endoprosthetic joint replacements. The recently published unified classification system (UCS) has replaced numerous historical classification systems and can be applied to all PPFx regardless of the bone or joint involved. The treatment of PPFx requires individual therapeutic concepts taking patient-dependent and patient-independent factors into consideration. The conservative treatment of PPFx is only justified in exceptional situations. In contrast, the choice between operative treatment and deciding between osteosynthesis or revision arthroplasty is particularly based on the assessment of the implant stability. In order to achieve fracture consolidation and also a good functional outcome, knowledge of the basic biomechanical principles of operative (osteosynthesis or endoprosthesis) treatment of periprosthetic fractures is necessary.
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Background: Angular stable plate fixation is a widely accepted treatment option for interprosthetic or periprosthetic femoral fractures with stable implants. This biomechanical study tries to establish a safe distance of the plate from the tip of a femoral prosthesis. Methods: A total of 38 composite femurs were reamed to an inner diameter of 23 mm to create an osteoporotic bone model. A Weber hip stem was cemented into each and a distal femoral NCB plate applied with the distance to the stem varying from 8 cm apart to 6 cm overlap in 2-cm steps. Each specimen was tested in cyclic axial loading (400 N-1500 N) and then cyclic torsion (0.6 Nm-50 Nm). Peak strain on the femur around the tip of the plate was measured with a 3D image correlation system and averaged over 26 cycles (excluding the first 3 and the last cycles). Finally, each femur was axially loaded to failure. Results: Strain increased with decreasing overlap or gap. Seven specimens failed early between 2-cm overlap and 2-cm gap. Results were divided into a far group with a distance of >4 cm and a close group of <4 cm. Strain was significantly higher in the close group for axial (P < .001) and torsional (P < .001) loading. Failure load was significantly lower in the close group (P = .002). Conclusion: A minimal gap and/or overlap of at least 6 cm is recommended in osteoporotic bone to avoid stress risers.
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Periprosthetic fractures of the femur are increasing due to the increase of arthroplasties and the aging population. They concern a population that is often elderly and with important comorbidities that complicate managing this already complex pathology. Usual complications of classic osteosynthesis are numerous, including infections and nonunions and the need for delayed weight bearing after surgery. The development of locking plates has allowed complication avoidance. When used in minimally invasive surgery, they combine the biological advantages of closed-wound surgery to the mechanical advantages of locking plates, which have better stability in fragile bones. We propose a technical update on handling such fractures by using locking plates under minimally invasive surgery. In our experience, under certain guidelines, this allows for immediate post-operative full weight bearing, which is beneficial to these often elderly patients.
Article
Résumé Introduction La fracture périprothétique du fémur (FPF) est une complication sérieuse des arthroplasties de hanche pour laquelle différents matériels d’ostéosynthèse sont proposés. Toutefois, aucune étude n’a rapporté les résultats obtenus avec une plaque anatomique non verrouillée avec des trous excentrés. Les objectifs de ce travail étaient de présenter sur une population de FPF du groupe B selon Vancouver : (1) le taux de consolidation des FPF traitées par cet implant, (2) le taux de complications et (3) les résultats en termes d’autonomie. Hypothèse L’utilisation de cette plaque permet d’obtenir un taux élevé de consolidation avec un minimum de complications mécaniques. Matériels et méthodes Quarante-trois patients, d’âge moyen 79 ans ± 13 (41–98), qui ont été traités pour une ostéosynthèse d’une FPF de type B selon Vancouver avec cette plaque entre 2002 et 2007 ont été inclus. Le délai de consolidation et le score de Parker ont été évalués. La survie sans révision (toutes causes confondues) a été calculée par la méthode de Kaplan-Meier. Le recul moyen était de 42 mois ± 20 (16–90). Résultats La consolidation a été obtenue chez tous les patients avec un délai moyen de 2,4 mois ± 0,6 (2–4). Nous déplorons 1 patient avec un cal vicieux en varus. Le score de Parker a diminué de 5,93 ± 1,94 (2–9) à 4,93 ± 1,8 (1–9) (p = 0,01). Deux révisions chirurgicales ont été nécessaires sur la série (une infection survenue à 4,5 ans et un descellement fémoral). Le taux de survie à 5 ans des prothèses après ostéosynthèse était de 83,3 ± 12,6 %. Conclusion Cette plaque anatomique avec trous excentrés permet le traitement des FPF du type B et garantit une consolidation de la fracture avec un faible taux de complications liées à l’ostéosynthèse. Toutefois, les FPF représentent une complication sérieuse des arthroplasties de hanche assortie d’un fort taux de morbidités et de mortalité. Niveau de preuve Étude rétrospective thérapeutique niveau IV.
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This work evaluated activity levels in a group of healthy older adults to establish a target activity level for adults of similar age after total joint arthroplasty (TJA).With the decreasing age of TJA patients, it is essential to have a reference for activity level in younger patients as activity level affects quality of life and implant design. 54 asymptomatic, healthy older adults with no clinical evidence of lower extremity OA participated. The main outcome measure, average daily step count, was measured using an accelerometer-based activity monitor. On average the group took 8813 ± 3611 steps per day, approximately 4000 more steps per day than has been previously reported in patients following total joint arthroplasty. The present work provides a reference for activity after joint arthroplasty which is relevant given the projected number of people under the age of 65 who will undergo joint arthroplasty in the coming years.
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This study evaluated 5 currently used periprosthetic femoral shaft fracture fixation techniques to determine which technique provided the greatest fixation stability. Periprosthetic fractures in 30 synthetic femurs were fixed with a plate with cables, plate with proximal cables and distal bicortical screws (Ogden concept), plate with proximal unicortical screws and distal bicortical screws, plate with proximal unicortical screws and cables and distal bicortical screws, or 2 allograft cortical strut grafts with cables. These specimens were then tested in 3 physiologic loading modes. The plate constructs with proximal unicortical screws and distal bicortical screws or with proximal unicortical screws, proximal cables, and distal bicortical screws were significantly more stable in axial compression, lateral bending, and torsional loading than the other fixation constructs studied.
Stable fixation of periprosthetic or periimplant fractures with an angular stable plate and early weight bearing as tolerated. Periprosthetic femur fractures around the hip, Vancouver type B1 or C. Periprosthetic femur and tibia fractures around the knee. Periprosthetic fractures of the humerus. Periimplant fractures after intramedullary nailing. Loosening of prosthesis. Local infection. Osteitis. Preoperative planning is recommended. After minimally invasive fracture reduction and preliminary fixation, submuscular insertion of a large fragment femoral titanium plate or a distal femur plate. The plate is fixed with locking head screws and/or regular cortical screws where possible. If stability is insufficient, one or two locking attachment plates (LAP) are mounted to the femoral plate around the stem of the prosthesis. After fixing the LAP to one of the locking holes of the femoral plate, 3.5 mm screws are used to connect the LAP to the cortical bone and/or cement mantle of the prosthesis. Weight bearing as tolerated starting on postoperative day 1 is suggested under supervision of a physiotherapist. In 6 patients with periprosthetic fractures and 2 patients with periimplant fractures, no surgical complications (e.g., wound infection or bleeding) were observed. The mean time to bony union was 14 weeks. No implant loosening of the locking attachment plate was observed. At the follow-up examination, all patients had reached their prefracture mobility level.
Article
Biomechanical testing has been a cornerstone for the development of surgical implants used in fracture stabilisation. In a multi-disciplinary collaboration complex at the University of Wales, Swansea, novel computerised clinically relevant models were developed using advanced computational engineering. In-house software (developed initially for commercial aerospace engineering), allowed accurate finite element analysis (FEA) models of the whole femur to be created, including the internal architecture of the bone, by means of linear interpolation of greyscale images from multiaxial CT scans. This allowed for modelling the changing trabecular structure and bone mineral density as seen in progressive osteoporosis. Falls from standing were modelled in a variety of directions (with and without muscle action) using analysis programmes which resulted in fractures consistent with those seen in clinical practice. By meshing implants into these models and repeating the mechanism of injury in simulation, periprosthetic fractures were also recreated. Further development with simulated physiological activities (e.g. walking and rising from sitting) along with attrition in the bone (in the boundary zones where stress concentration occurs) will allow further known modes of failure in implants to be reproduced. Robust simulation of macro and micro-scale events will allow the testing of novel new designs in simulations far more complex than conventional biomechanical testing will allow.
Article
We prospectively followed 191 consecutive collarless polished tapered (CPT) femoral stems, implanted in 175 patients who had a mean age at operation of 64.5 years (21 to 85). At a mean follow-up of 15.9 years (14 to 17.5), 86 patients (95 hips) were still alive. The fate of all original stems is known. The 16-year survivorship with re-operation for any reason was 80.7% (95% confidence interval 72 to 89.4). There was no loss to follow-up, with clinical data available on all 95 hips and radiological assessment performed on 90 hips (95%). At latest follow-up, the mean Harris hip score was 78 (28 to 100) and the mean Oxford hip score was 36 (15 to 48). Stems subsided within the cement mantle, with a mean subsidence of 2.1 mm (0.4 to 19.2). Among the original cohort, only one stem (0.5%) has been revised due to aseptic loosening. In total seven stems were revised for any cause, of which four revisions were required for infection following revision of the acetabular component. A total of 21 patients (11%) required some sort of revision procedure; all except three of these resulted from failure of the acetabular component. Cemented acetabular components had a significantly lower revision burden (three hips, 2.7%) than Harris Galante uncemented components (17 hips, 21.8%) (p < 0.001). The CPT stem continues to provide excellent radiological and clinical outcomes at 15 years following implantation. Its results are consistent with other polished tapered stem designs.
Article
The rate of periprosthetic femoral fractures after hip arthroplasty is rising and the estimated current lifetime incidence is 0.4-2.1%. While most authors recommend revision arthroplasty in patients with loose femoral shaft components, treatment options for patients with stable stem are not fully elucidated. Against this background we performed a retrospective chart analysis with clinical follow-up examination of 32 cases that sustained a Vancouver type B1 or C periprosthetic fracture (stable stem). Overall 16 cases were treated by open reduction and internal fixation (ORIF) by plate osteosynthesis and 16 cases by revision arthroplasty (RA). Both groups were comparable regarding age, gender, follow-up time interval, time interval from primary hip arthroplasty to fracture and rate of cemented femoral components, but more type C fractures were treated by ORIF. Functional outcome expressed by the median timed "Up and Go" test did not differ significantly (30 s ORIF vs. 24 s RA, P = 0.19). However, by comparable systemic complications surgery-related complications were significantly more frequent in plate osteosynthesis (ORIF n = 10 vs. RA n = 3, P = 0.03). Based on our results, further studies, preferable via a multicenter approach, should focus on identifying patients that benefit from ORIF in periprosthetic fractures. A misinterpretation of type B2 fractures with loose implant as type B1 fractures may cause implant failure in case of ORIF. The use of angular stable implants, additional cable wires or bone enhancing means is recommended.
Article
The use of plate-and-cable constructs to treat periprosthetic fractures around a well-fixed femoral component in total hip replacements has been reported to have high rates of failure. Our aim was to evaluate the results of a surgical treatment algorithm to use these lateral constructs reliably in Vancouver type-B1 and type-C fractures. The joint was dislocated and the stability of the femoral component was meticulously evaluated in 45 type-B1 fractures. This led to the identification of nine (20%) unstable components. The fracture was considered to be suitable for single plate-and-cable fixation by a direct reduction technique if the integrity of the medial cortex could be restored. Union was achieved in 29 of 30 fractures (97%) at a mean of 6.4 months (3 to 30) in 29 type-B1 and five type-C fractures. Three patients developed an infection and one construct failed. Using this algorithm plate-and-cable constructs can be used safely, but indirect reduction with minimal soft-tissue damage could lead to shorter times to union and lower rates of complications.
Article
Periprosthetic fractures after cemented hip replacement are a challenging problem to manage. Biomechanical studies have suggested the benefit of using locking screws for plate fixation, but there are concerns whether screws damage the cement mantle and promote crack propagation leading to construct failure. In this biomechanical study, different screw types were implanted into the cement mantle after pre-drilling holes of different sizes, in unicortical and bicortical configuration. The presence of cracks and the pull-out resistance of these screws were then evaluated. No unicortical screw induced cracks. Screws with a shortened tip, smaller flutes and double threads were significantly better for pull-out resistance. Bicortical screws were associated with a risk of local cement mantle damage, but also with a significantly greater holding power. By increasing the drill diameter, the onset of cracks decreased, but so does the pull-out resistance.
Article
A telemeterized total hip prosthesis was implanted in one patient and force-data were obtained. Thirty-one days postoperatively, the magnitude of the joint-contact force during double-limb stance was 1.0 times body weight. During ipsilateral single-limb stance the joint-contact force was 2.1 times body weight, and during the stance phase of gait the peak force typically was 2.6 to 2.8 times body weight, with the resultant force located on the anterosuperior portion of the ball. During stair-climbing, the force was 2.6 times body weight. At peak loads, the angle between the resultant force and the axis of the neck was 30 to 35 degrees and that between the resultant force and the plane of the prosthesis was 20 degrees. During stair-climbing or straight-leg raising, the out-of-plane orientation of the resultant force increased substantially. These data provide information concerning the forces that must be sustained by prosthetic hip joints during a number of common activities of daily living within the first month after implantation. The results also provide insight into the progression of early recovery and demonstrate the variety of forces that are generated during this period.
Article
The resultant hip joint force, its orientation and the moments were measured in two patients during walking and running using telemetering total hip prostheses. One patient underwent bilateral joint replacement and a second patient, additionally suffering from a neuropathic disease and atactic gait patterns, received one instrumented hip implant. The joint loading was observed over the first 30 and 18 months, respectively, following implantation. In the first patient the median peak forces increased with the walking speed from about 280% of the patient's body weight (BW) at 1 km h-1 to approximately 480% BW at 5 km h-1. Jogging and very fast walking both raised the forces to about 550% BW; stumbling on one occasion caused magnitudes of 720% BW. In the second patient median forces at 3 km h-1 were about 410% BW and a force of 870% BW was observed during stumbling. During all types of activities, the direction of the peak force in the frontal plane changed only slightly when the force magnitude was high. Perpendicular to the long femoral axis, the peak force acted predominantly from medial to lateral. The component from ventral to dorsal increased at higher force magnitudes. In one hip in the first patient and in the second patient the direction of large forces approximated the average anteversion of the natural femur. The torsional moments around the stem of the implant were 40.3 N m in the first patient and 24 N m in the second.
Article
Transverse fractures at the distal tip of a well-fixed femoral prosthesis are difficult to stabilize using plates and screws due to the presence of the underlying intramedullary stem. The attachment of plates using cerclage wires obviates the need for screws, but the stability provided by cerclage plating is a clinical concern. In this study we compared the mechanical performance of three wire-cerclage plating techniques: (a) simple cerclage (each wire wrapped around the bone and plate once); (b) double cerclage (each wire wrapped around the bone and plate twice); and (c) a new method that used small stainless steel inserts that fit into the plate holes and permit the direct coupling of the cerclage wires to the plate. To compare the performance of the three fixation constructs, synthetic femora were osteotomized, stabilized with a wire cerclage plating technique, and subjected to monotonic and cyclic loading using a Materials Testing System (Minneapolis, MN) servo-hydraulic testing system. The performance of each construct was evaluated using seven different mechanical parameters (four monotonic, three cyclic). Double cerclage performed significantly better than did simple cerclage for three of the seven mechanical parameters. The insert technique performed significantly better than did the simple and double cerclage techniques for all seven of the measured mechanical parameters. For both monotonic and cyclic loading, the use of inserts resulted in an improvement in fixation strength and stability in comparison with conventional simple and double cerclage plating techniques. The insert technique shows promise in the treatment of this difficult type of fracture at the distal tip of a well-fixed femoral prosthesis.
Article
Six techniques for the surgical management of fractures of the femur about the tip of the stem of a total hip arthroplasty were evaluated. Seven embalmed human femurs were prepared to receive the correct-size femoral component of a total hip system. A transverse osteotomy was performed at the level of the tip of the stem. Stability and strength of each reconstruction were tested on each femur under semidynamic loading conditions. This study showed that cementless revision to a long-stem prosthesis does not provide adequate stability. The highest strength and stability were achieved by supplementing the long-stem conversion with allograft struts and cable cerclage. Good results were obtained by lateral compression plating with unicortical screws proximally. Failure was due to pull-out of the proximal screws.
Article
Composite synthetic models of the human femur have recently become commercially available as substitutes for cadaveric specimens. Their quick diffusion was justified by the advantages they offer as a substitute for real femurs. The present investigation concentrated on an extensive experimental validation of the mechanical behaviour of the whole bone composite model, compared to human fresh-frozen and dried-rehydrated specimens for different loading conditions. First, the viscoelastic behaviour of the models was investigated under simulated single leg stance loading, showing that the little time dependent phenomena observed tend to extinguish within a few minutes of the load application. The behaviour under axial loading was then studied by comparing the vertical displacement of the head as well as the axial strains, by application of a parametric descriptive model of the strain distribution. Finally, a four point bending test and a torsional test were performed to characterize the whole bone stiffness of the femur. In all these tests, the composite femurs were shown to fall well within the range for cadaveric specimens, with no significant differences being detected between the synthetic femurs and the two groups of cadaveric femurs. Moreover, the interfemur variability for the composite femurs was 20-200 times lower than that for the cadaveric specimens, thus allowing smaller differences to be characterized as significant using the same simple size, if the composite femurs are employed.
Article
To determine whether the mechanical properties of first-generation interlocking femoral nails are different from those of second-generation interlocking femoral nails in a subtrochanteric femur fracture model. Randomized laboratory investigation using a synthetic subtrochanteric femur fracture model. Simulated stable and unstable fractures were created at three levels in the subtrochanteric region of synthetic femora. Instrumented specimens were tested elastically in a biomaterials testing system. Synthetic femora were instrumented with either a statically locked first-generation femoral nail or a statically locked second-generation femoral nail. Elastic stiffness for both the stable and unstable fracture groups was measured in both compression and torsion. Unstable fracture specimens were tested to failure in compression, and load to failure was measured. Throughout the subtrochanteric region, second-generation femoral nail constructs were consistently stiffer in compression and torsion than were statically locked first-generation femoral nail constructs. In general, second-generation constructs also withstood larger loads to failure in the unstable fracture model. Second-generation nails provided significantly enhanced mechanical stiffness compared with first-generation femoral nails when used to treat both stable and unstable subtrochanteric femur fractures. Although these results were obtained by using a well-controlled, mechanically consistent model, clinical validation of an increased incidence of fracture unions or of decreased time to union is required before we can recommend that second-generation nails be used routinely to treat subtrochantenic femur fractures.
Article
This study assessed the reliability and validity of a new classification system for fractures of the femur after hip arthroplasty. Forty radiographs were evaluated by 6 observers, 3 experts and 3 nonexperts. Each observer read the radiographs on 2 separate occasions and classified each case as to its type (A, B, C) and subtype (B1, B2, B3). Reliability was assessed by looking at the intraobserver and interobserver agreement using the kappa statistic. Validity was assessed within the B group by looking at the agreement between the radiographic classification and the intraoperative findings. Our findings suggest that this classification system is reliable and valid. Intraobserver agreement was consistent across observers, ranging from 0.73 to 0.83. There was a negligible difference between experts and nonexperts. Interobserver agreement was 0.61 for the first reading and 0.64 for the second reading by kappa analysis, indicating substantial agreement between observers. Validity analysis revealed an observed agreement kappa value of 0.78, indicating substantial agreement. This study has shown that this classification is reliable and valid.
Article
To test the initial stability of a newly designed partially cemented femoral stem in comparison with a fully cemented conventional stem. An in vitro study to determine the interface motion between femoral stem and bone as a response to loading. The aim of the new prosthesis design is a proximal load transfer by a defined partial cement fixation in the proximal femur region and a slim prosthesis stem in the distal region. Before a clinical study can be started, the new stem has to show an initial stability comparable to that of fully cemented prostheses. Six paired fresh cadaveric femora were used for the testing of the new partially cemented stem (Option 3000, Mathys Orthopaedics, Bettlach, Switzerland) and a fully cemented stem (Weber Shaft, AlloPro, Baar, Swizerland). Under cyclic loading up to 1600 N hip joint forces, the interface motion between implants and bone was measured at six locations. Both stems showed uncritical interface motions below 43 microm. However, the Option 3000 stem exhibited significantly smaller motions in the proximal region and slightly larger movements in the distal regions than the Weber prosthesis. The new type of partially cemented stem provided a comparable initial stability to the fully cemented Weber prosthesis. Relevance The high initial stability of the Option 3000 stem justified the clinical use of the new implant. More than 100 implantations in the last three years, with very good preliminary clinical results, support the preclinical findings.
Article
In vivo loads acting at the hip joint have so far only been measured in few patients and without detailed documentation of gait data. Such information is required to test and improve wear, strength and fixation stability of hip implants. Measurements of hip contact forces with instrumented implants and synchronous analyses of gait patterns and ground reaction forces were performed in four patients during the most frequent activities of daily living. From the individual data sets an average was calculated. The paper focuses on the loading of the femoral implant component but complete data are additionally stored on an associated compact disc. It contains complete gait and hip contact force data as well as calculated muscle activities during walking and stair climbing and the frequencies of daily activities observed in hip patients. The mechanical loading and function of the hip joint and proximal femur is thereby completely documented. The average patient loaded his hip joint with 238% BW (percent of body weight) when walking at about 4 km/h and with slightly less when standing on one leg. This is below the levels previously reported for two other patients (Bergmann et al., Clinical Biomechanics 26 (1993) 969-990). When climbing upstairs the joint contact force is 251% BW which is less than 260% BW when going downstairs. Inwards torsion of the implant is probably critical for the stem fixation. On average it is 23% larger when going upstairs than during normal level walking. The inter- and intra-individual variations during stair climbing are large and the highest torque values are 83% larger than during normal walking. Because the hip joint loading during all other common activities of most hip patients are comparably small (except during stumbling), implants should mainly be tested with loading conditions that mimic walking and stair climbing.
Article
The LISS-DF (Less invasive stabilization system-distal femur) is a new type of implant system for the treatment of distal femoral fractures according to the principles of "Minimally Invasive Surgery". A plate, pre-contoured to the anatomy, is inserted through a minimally invasive incision into the epiperiosteal space by means of an aiming device after indirect, closed fracture reduction. The implant is stabilized by insertion of screws which lock into the plate holes and prevent tilting. This is performed with the aid of an aiming device and through stab incisions. It is not necessary for a large area to be exposed at the fracture site. As part of an AO prospective multicenter study, the new system was applied to 112 patients with 116 fractures. The time to follow-up was on average 13.7 months (minimum 7 months, maximum 33 months). Fractures treated were distal femoral shaft and supracondylar femoral fractures. Eight patients died during the study of causes unrelated to the implant. Of the remaining 104 patients with 107 fractures, 96 patients with 99 fractures were available for complete follow-up (93% follow-up rate). In 90% of all cases treated and followed up, the fracture had consolidated during the period of observation. Twenty-three revision operations were necessary in 21 patients. In two cases, implant failure occurred as the result of a pseudarthrosis. The complications can be attributed in nearly all cases to the severity of the trauma and/or a lack of experience when applying the new style implant to a wider range of indications. The results of the study show that with a sound knowledge of the operative technique and careful preoperative planning this system represents an excellent, safe procedure for the treatment of almost all distal femoral fracture types including periprosthetic fractures of the distal femur. There is generally no need for primary cancellous bone grafting.
Article
The application of indirect reduction techniques has improved fracture-healing and reduced the need for bone-grafting compared with the outcomes of older, direct reduction techniques. We investigated the results of such indirect reduction techniques for the treatment of periprosthetic femoral shaft fractures. Fifty consecutive patients with a femoral shaft fracture about a stable intramedullary implant (a Vancouver Type-B1 fracture) were treated with a protocol that included open reduction with use of indirect reduction techniques and internal fixation with a single lateral plate without structural allografting or other bone-grafting. Four patients died in the early postoperative period, and five had inadequate follow-up. The remaining forty-one patients (average age, seventy-two years) were evaluated clinically and radiographically at an average of twenty-four months. All fractures healed in satisfactory alignment at an average of twelve weeks (range, seven to twenty-three weeks) after the index procedure. One patient had one fractured cable and two others had one fractured screw, but all of the fractures healed without evidence of implant loosening or malalignment. There was one deep infection in the perioperative period. Thirty of the forty-one patients returned to their baseline ambulatory status. The results of this study support the use of indirect open reduction and internal fixation with a single extraperiosteal lateral plate, without the use of allograft struts, for the treatment of a femoral shaft fracture about a stable intramedullary implant. Therapeutic Level IV.
Article
Postoperative femoral periprosthetic fracture is an uncommon complication of total hip arthroplasty surgery, but several centers worldwide have recently reported an increase in total numbers of such fractures. This severe complication is costly for society and results in high morbidity. Our analysis of 1049 periprosthetic fractures occurring in Sweden between 1979 and 2000 and recorded in the Swedish National Hip Arthroplasty Register focuses on patient- and implant-related factors, fracture classification, and fracture frequency. These were our 3 major findings: (1) a majority of the patients who sustained a late periprosthetic femoral fracture had a loose stem. (2) Implant-related factors are significantly associated with occurrence of a periprosthetic fracture. (3) Since the 1980s in Sweden, treatment results for periprosthetic fractures have been poor, with low long-term survivorship and a high frequency of complications. We have initiated further studies of this important problem.
Article
To determine which of 2 techniques for the treatment of periprosthetic femoral shaft fractures is of greater stiffness. A laboratory study using 8 pairs of matched, embalmed femurs. Femurs implanted with a cemented total hip prosthesis had a simulated periprosthetic femur fracture created distal to the implant. Fractures were fixed with a plate with locked screws or a plate with cables (Ogden construct). Fixation stability was compared in various loading modalities before and after cycling. Failure in torsional loading was then determined. The cement mantle was tested for crack propagation that may have occurred secondary to locked screw insertion and loading. Fixation stiffness (the ratio of applied load to displacement at the fracture site), torsional strength, mode of failure for each system, and cement mantle evaluation for cracks after screw insertion. Locked plating was stiffer than the Ogden construct in pre- and post-cyclic axial loading and torsion. There was no difference in lateral bending stability or torsional failure loads. Locked plating constructs were stiffer than the Ogden construct in axial loading and torsion. Although no differences in loads to failure during torsion were noted, locked plating constructs exhibited catastrophic failure not observed with the Ogden construct.
Article
The purpose of this study was to determine the demographics, incidence, and results of treatment of periprosthetic fractures in a nationwide observational study. In the years 1999 and 2000, 321 periprosthetic fractures were reported to the Swedish National Hip Arthroplasty Register. All of the associated hospital records were collected. At the time of follow-up, the Harris hip score, a health-related quality-of-life measure (the EuroQol-5D [EQ-5D] index), and patient satisfaction were used as outcome measurements. A radiologist performed the radiographic evaluation. Ninety-one patients, with a mean age of 73.8 years, sustained a fracture after one or several revision procedures, and 230 patients, with a mean age of 77.9 years, sustained a fracture after a primary total hip replacement. Minor trauma, including a fall to the floor, and a spontaneous fracture were the main etiologies for the injuries. A high number of patients had a loose stem at the time of the fracture (66% in the primary replacement group and 51% in the revision group). Eighty-eight percent of the fractures were classified as Vancouver type B; however, there was difficulty with preoperative categorization of the fractures radiographically. There was a high failure rate resulting in a low short to mid-term prosthetic survival rate. The sixty-six-month survival rate for the entire fracture group, with reoperation as the end point, was 74.8% +/- 5.0%. One factor associated with fracture risk was implant design. On the basis of these findings, we believe that high-risk patients should have routine radiographic follow-up. Such a routine could identify a loose implant and make intervention possible before a fracture occurred. Furthermore, we recommend an exploration of the joint to test the stability of the implant in patients with a Vancouver type-B fracture in which the stability of the stem is uncertain.
Article
Periprosthetic femoral fractures (PFF) are increasing as a result of changes in population demographics and the increase in the number of total hip replacements performed. The overall incidence has been reported to range from 0.1% to 6% of all total hip arthroplasties. Management of these fractures is often particularly demanding, complex and expensive. In many cases, the surgeon has to solve the simultaneous problems of implant loosening, bone loss and fracture. A thorough understanding of the unique characteristics of the different fracture types, the principles of PFF treatment and a familiarity with the various fixation devices, grafts and prosthetic implants are all of paramount importance. Internal fixation is used either alone or as an adjunct to stem revision. The stability of the original implant and the configuration of the fracture itself are the basic factors that influence the decision-making process. The current study reviews the existing literature on internal fixation of femoral periprosthetic fractures.
Article
Many methods have been described to stabilise periprosthetic fractures around a total hip arthroplasty. Locking plate fixation offers increased angular stability and, theoretically, better fixation in osteoporotic bone. This study presents our results with the use of locking plate fixation for Vancouver Type B1 and Type C periprosthetic fractures following total hip arthroplasty (THA). Twelve patients underwent fixation of periprosthetic fractures with either a locking compression plate (LCP) or a distal femur less invasive stabilisation system (LISS). There were six Type B1 and six Type C fractures. One patient died soon after surgery. The mean follow-up was 13.9 months (range 12-18 months). The fracture healed in 10 of the remaining 11 patients with a median time to union of 4.8 months. There was one implant failure prior to fracture healing and one implant failure after fracture healing. Both were attributed to technical errors. Seven patients returned to their previous level of mobility. Two patients required the use of one walking stick after fracture healing, but had been able to walk unaided before their fall. One patient required two sticks, after previously requiring only a single stick. There were no infections. Our experience encourages us that locking plates have a role to play in managing periprosthetic fractures around a stable femoral stem, especially in patients with poor soft tissue and osteoporosis.
Article
We report the application of a new fixed angle plate (NCB DF, Zimmer inc. USA, Warsaw, IN) in the treatment of periprosthetic femur fractures. The NCB DF combines conventional plating technique with polyaxial screw placement and angular stability. Prospective cohort study. A single level-1 trauma center. From May 2003 to December 2005, a total of 24 patients with periprosthetic femur fractures were treated. The NCB DF femur plate was used in all cases. The average follow-up period was 12 months (3-31 months). Twelve patients had a periprosthetic fracture after total knee replacement (TKA) and 12 patients after total hip replacement (THA). The mean period from primary joint replacement to periprosthetic fracture was 8.2 years for the THA group and 7.2 years for the TKA group. A combined conventional/locking surgical technique was performed in all the cases. Union, non-union, mal-union, duration of surgery, range of motion, postoperative mobility, subjective patient satisfaction and complications. The union rate was 90%, the mal-union rate 5% and the re-operation rate 15%. Postoperative mobility reached the preoperative level in all but for two patients. Three complications occurred relating to the implant or the procedure: one fatigue failure of the plate (non-union), one screw breakage, and one wound infection. The NCB DF combines conventional plating technique with polyaxial screw placement and angular stability. This combination technique shows promising results regarding union and mal-union rates in periprosthetic fractures in elderly and osteoporotic patients.