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Eleftherios Tsiridis - One of the best experts on this subject based on the ideXlab platform.
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Periprosthetic Fracture fixation of the femur following total hip arthroplasty: A review of biomechanical testing
Clinical Biomechanics, 2018Co-Authors: Mehran Moazen, Alison C. Jones, Ruth K. Wilcox, Eleftherios TsiridisAbstract:Abstract 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.
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application of far cortical locking technology in periprosthetic Femoral Fracture fixation a biomechanical study
Journal of Arthroplasty, 2016Co-Authors: Mehran Moazen, Eleftherios Tsiridis, Andreas Leonidou, Joseph Pagkalos, Arsalan Marghoub, Michael J FaganAbstract:Abstract Background Lack of Fracture movement could be a potential cause of periprosthetic Femoral Fracture (PFF) fixation failures. This study aimed to test whether the use of distal far cortical locking screws reduces the overall stiffness of PFF fixations and allows an increase in Fracture movement compared to standard locking screws while retaining the overall strength of the PFF fixations. Methods Twelve laboratory models of Vancouver type B1 PFFs were developed. In all specimens, the proximal screw fixations were similar, whereas in 6 specimens, distal locking screws were used, and in the other six specimens, far cortical locking screws. The overall stiffness, Fracture movement, and pattern of strain distribution on the plate were measured in stable and unstable Fractures under anatomic 1-legged stance. Specimens with unstable Fracture were loaded to failure. Results No statistical difference was found between the stiffness and Fracture movement of the two groups in stable Fractures. In the unstable Fractures, the overall stiffness and Fracture movement of the locking group was significantly higher and lower than the far cortical group, respectively. Maximum principal strain on the plate was consistently lower in the far cortical group, and there was no significant difference between the failure loads of the 2 groups. Conclusion The results indicate that far cortical locking screws can reduce the overall effective stiffness of the locking plates and increase the Fracture movement while maintaining the overall strength of the PFF fixation construct. However, in unstable Fractures, alternative fixation methods, for example, long stem revision might be a better option.
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periprosthetic Femoral Fracture a biomechanical comparison between vancouver type b1 and b2 fixation methods
Journal of Arthroplasty, 2014Co-Authors: Alison C. Jones, Ruth K. Wilcox, Eleftherios Tsiridis, Mehran Moazen, Jonathan H Mak, Lee W Etchels, Zhongmin JinAbstract:Current clinical data suggest a higher failure rate for internal fixation in Vancouver type B1 periprosthetic Femoral Fracture (PFF) fixations compared to long stem revision in B2 Fractures. The aim of this study was to compare the biomechanical performance of several fixations in the aforementioned Fractures. Finite element models of B1 and B2 fixations, previously corroborated against in vitro experimental models, were compared. The results indicated that in treatment of B1 Fractures, a single locking plate can be without complications provided partial weight bearing is followed. In case of B2 Fractures, long stem revision and bypassing the Fracture gap by two Femoral diameters are recommended. Considering the risk of single plate failure, long stem revision could be considered in all comminuted B1 and B2 Fractures.
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rigid versus flexible plate fixation for periprosthetic Femoral Fracture computer modelling of a clinical case
Medical Engineering & Physics, 2012Co-Authors: Mehran Moazen, Alison C. Jones, Ruth K. Wilcox, Eleftherios Tsiridis, Zhongmin Jin, Andreas LeonidouAbstract:A variety of plate designs have been implemented for treatment of periprosthetic Femoral Fracture (PFF) fixation. Controversy, however, exists with regard to optimum fixation methods using these plates. A clinical case of a PFF fixation (Vancouver type C) was studied where a rigid locking plate fixation was compared with a more flexible non-locking approach. A parametric computational model was developed in order to understand the underlying biomechanics between these two fixations. The model was used to estimate the overall stiffness and Fracture movement of the two implemented methods. Further, the differing aspects of plate design and application were incrementally changed in four different models. The clinical case showed that a rigid fixation using a 4.5 mm titanium locking plate with a short bridging length did not promote healing and ultimately failed. In contrast, a flexible fixation using 5.6 mm stainless steel non-locking plate with a larger bridging length promoted healing. The computational results highlighted that changing the bridging length made a more substantial difference to the stiffness and Fracture movement than varying other parameters. Further the computational model predicted the failure zone on the locking plate. In summary, rigid Fracture fixation in the case of PFF can suppress the Fracture movement to a degree that prevents healing and may ultimately fail. The computational approach demonstrated the potential of this technique to compare the stiffness and Fracture movement of different fixation constructs in order to determine the optimum fixation method for PFF.
Mehran Moazen - One of the best experts on this subject based on the ideXlab platform.
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Periprosthetic Fracture fixation of the femur following total hip arthroplasty: A review of biomechanical testing
Clinical Biomechanics, 2018Co-Authors: Mehran Moazen, Alison C. Jones, Ruth K. Wilcox, Eleftherios TsiridisAbstract:Abstract 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.
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application of far cortical locking technology in periprosthetic Femoral Fracture fixation a biomechanical study
Journal of Arthroplasty, 2016Co-Authors: Mehran Moazen, Eleftherios Tsiridis, Andreas Leonidou, Joseph Pagkalos, Arsalan Marghoub, Michael J FaganAbstract:Abstract Background Lack of Fracture movement could be a potential cause of periprosthetic Femoral Fracture (PFF) fixation failures. This study aimed to test whether the use of distal far cortical locking screws reduces the overall stiffness of PFF fixations and allows an increase in Fracture movement compared to standard locking screws while retaining the overall strength of the PFF fixations. Methods Twelve laboratory models of Vancouver type B1 PFFs were developed. In all specimens, the proximal screw fixations were similar, whereas in 6 specimens, distal locking screws were used, and in the other six specimens, far cortical locking screws. The overall stiffness, Fracture movement, and pattern of strain distribution on the plate were measured in stable and unstable Fractures under anatomic 1-legged stance. Specimens with unstable Fracture were loaded to failure. Results No statistical difference was found between the stiffness and Fracture movement of the two groups in stable Fractures. In the unstable Fractures, the overall stiffness and Fracture movement of the locking group was significantly higher and lower than the far cortical group, respectively. Maximum principal strain on the plate was consistently lower in the far cortical group, and there was no significant difference between the failure loads of the 2 groups. Conclusion The results indicate that far cortical locking screws can reduce the overall effective stiffness of the locking plates and increase the Fracture movement while maintaining the overall strength of the PFF fixation construct. However, in unstable Fractures, alternative fixation methods, for example, long stem revision might be a better option.
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periprosthetic Femoral Fracture a biomechanical comparison between vancouver type b1 and b2 fixation methods
Journal of Arthroplasty, 2014Co-Authors: Alison C. Jones, Ruth K. Wilcox, Eleftherios Tsiridis, Mehran Moazen, Jonathan H Mak, Lee W Etchels, Zhongmin JinAbstract:Current clinical data suggest a higher failure rate for internal fixation in Vancouver type B1 periprosthetic Femoral Fracture (PFF) fixations compared to long stem revision in B2 Fractures. The aim of this study was to compare the biomechanical performance of several fixations in the aforementioned Fractures. Finite element models of B1 and B2 fixations, previously corroborated against in vitro experimental models, were compared. The results indicated that in treatment of B1 Fractures, a single locking plate can be without complications provided partial weight bearing is followed. In case of B2 Fractures, long stem revision and bypassing the Fracture gap by two Femoral diameters are recommended. Considering the risk of single plate failure, long stem revision could be considered in all comminuted B1 and B2 Fractures.
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rigid versus flexible plate fixation for periprosthetic Femoral Fracture computer modelling of a clinical case
Medical Engineering & Physics, 2012Co-Authors: Mehran Moazen, Alison C. Jones, Ruth K. Wilcox, Eleftherios Tsiridis, Zhongmin Jin, Andreas LeonidouAbstract:A variety of plate designs have been implemented for treatment of periprosthetic Femoral Fracture (PFF) fixation. Controversy, however, exists with regard to optimum fixation methods using these plates. A clinical case of a PFF fixation (Vancouver type C) was studied where a rigid locking plate fixation was compared with a more flexible non-locking approach. A parametric computational model was developed in order to understand the underlying biomechanics between these two fixations. The model was used to estimate the overall stiffness and Fracture movement of the two implemented methods. Further, the differing aspects of plate design and application were incrementally changed in four different models. The clinical case showed that a rigid fixation using a 4.5 mm titanium locking plate with a short bridging length did not promote healing and ultimately failed. In contrast, a flexible fixation using 5.6 mm stainless steel non-locking plate with a larger bridging length promoted healing. The computational results highlighted that changing the bridging length made a more substantial difference to the stiffness and Fracture movement than varying other parameters. Further the computational model predicted the failure zone on the locking plate. In summary, rigid Fracture fixation in the case of PFF can suppress the Fracture movement to a degree that prevents healing and may ultimately fail. The computational approach demonstrated the potential of this technique to compare the stiffness and Fracture movement of different fixation constructs in order to determine the optimum fixation method for PFF.
David G Lewallen - One of the best experts on this subject based on the ideXlab platform.
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total knee arthroplasty following prior distal Femoral Fracture
Knee, 2002Co-Authors: Elias C Papadopoulos, Javad Parvizi, Choon H Lai, David G LewallenAbstract:Abstract Background: Femoral Fracture may predispose the knee to the development of post-traumatic arthritis by either a direct intra-articular injury or residual limb malalignment. Malunion, intra-articular osseous defects, limb malalignment, retained internal fixation devices, and compromised surrounding soft tissues may in turn affect the outcome of total knee arthroplasty (TKA) in these patients. The aim of our study was to evaluate the result of TKA in patients with previous distal Femoral Fracture. Methods : The results of 48 cemented condylar total knee arthroplasties, performed between 1980 to 1998, in 47 patients with a previous distal Femoral Fracture were reviewed. There were 37 females and 10 males with an average age of 65 years (range, 19–84 years). Follow-up averaged 6.2 years (range, 2–16 years). No patients were lost to follow-up. Results : At the time of arthroplasty a Femoral Fracture non-union was present in three knees, all of which were treated with a long stem cemented Femoral component and bone grafting. Malunion, defined as angulation greater than 10° in the coronal plain or greater than 15° in the sagittal plain, was present in 21 knees. Of these, six underwent distal Femoral osteotomy during TKA. In the remaining 15 patients, with a malunion, the deformity was addressed by alterations in the orientation and location of bone resection. Other procedures were commonly needed at the time of arthroplasty and included: lateral retinacular release (22 knees), extensor mechanism realignment (eight knees), and collateral ligament reconstruction (two knees). The mean pre-operative Knee Society Scores were 40 (range, 0–80) for pain and 48 (range, 0–100) for function and improved significantly to a mean of 84 (range, 37–99) and 66 (range, 0–100) points, respectively, at the latest follow-up ( P P Conclusions : Significant improvement in function and relief of pain is seen in the vast majority of patients with previous distal Femoral Fractures undergoing subsequent TKA. However, these patients are at increased risk for restricted motion and perioperative complications following TKA. Special efforts to preserve the vascularity of the skin and subcutaneous tissues, restore limb alignment, ensure correct component positioning, and achieve soft tissue balance may help minimize the problems identified in this study.
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nonunion after periprosthetic Femoral Fracture associated with total hip arthroplasty
Journal of Bone and Joint Surgery American Volume, 1999Co-Authors: John R Crockarell, Daniel J Berry, David G LewallenAbstract:Background: Nonunion after a periprosthetic Femoral Fracture associated with total hip arthroplasty occurs rarely. There is little information, to our knowledge, regarding the prevalence of this complication, its treatment, and the functional outcomes of treatment. The purpose of this study was to identify the patterns and frequency of nonunions of Femoral Fractures around total hip prostheses and to evaluate the results and problems associated with treatment of this complication in a consecutive series of patients. Methods: The study included twenty-three nonunions of periprosthetic Femoral Fractures in twenty-three patients with an average age of fifty-five years (range, twenty-two to eighty-five years) at the time of the initiation of treatment of the nonunion. Thirteen of the Fractures occurred during or after a primary total hip arthroplasty, and ten occurred during or after a revision total hip arthroplasty. According to the classification system of Duncan and Masri, there were six B1 Fractures (associated with a well fixed prosthesis), seven B2 Fractures (associated with a loose stem), and ten B3 Fractures (associated with very poor proximal bone). Ten patients were managed with revision to a long-stem prosthesis. Six patients had revision to a proximal Femoral replacement prosthesis. A two-stage technique consisting of removal of the prosthesis and open reduction and internal fixation of the nonunion followed by reimplantation of the prosthesis was used in two patients. Two patients were managed initially with bone-grafting alone, and two patients were managed nonoperatively. One patient who had an infection at the site of the nonunion was managed definitively with resection arthroplasty. Results: The duration of clinical follow-up averaged 8.3 years (range, three months to twenty-three years), and that of radiographic surveillance averaged 7.0 years (range, eight months to seventeen years). Of the thirteen patients in whom an attempt to achieve union was made and for whom radiographs were available, nine eventually had bone-healing. Five of the twenty-three femora became infected and were treated with resection arthroplasty. Of the seventeen patients who had not had a resection arthroplasty for infection and for whom radiographs were available at the time of the most recent follow-up, eleven had a stable and well fixed implant and six had a loose implant as seen radiographically or had had a revision because of aseptic loosening. Seventeen patients had no or mild pain at the time of the most recent follow-up, but ten required two-handed support to walk. The overall complication rate was 52 percent (twelve of twenty-three patients). Conclusions: Nonunion of a Femoral Fracture associated with a total hip prosthesis is an infrequent problem. Treatment is difficult, with a high rate of complications and relatively poor functional outcomes. The data from this series must be interpreted with caution, as patients were managed over a period of three decades and many did not have the advantage of modern techniques of revision hip arthroplasty. Prevention of nonunion by optimum treatment of the initial Fracture is most important. Treatment of a Femoral nonunion about a total hip implant should be implemented on the basis of the status of the fixation of the prosthesis and the quality of the surrounding bone.
Hg Pandit - One of the best experts on this subject based on the ideXlab platform.
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Postoperative periprosthetic Femoral Fracture around total hip replacements: current concepts and clinical outcomes
'British Editorial Society of Bone & Joint Surgery', 2020Co-Authors: Ramavath A, Jn Lamb, Hg Pandit, Palan J, Sj JainAbstract:The rising incidence of postoperative periprosthetic Femoral Fracture (PFF) presents a significant clinical and economic burden. A detailed understanding of risk factors is required in order to guide preventative strategies. Different Femoral stems have unique characteristics and management strategies must be tailored appropriately. Consensus regarding treatment of PFFs around well-fixed stems is lacking, but revision surgery may provide more predictable outcomes for unstable Fracture patterns and Fractures around polished taper-slip stems. Future research should focus on implant-related risk factors, treatment of concurrent metabolic bone disease and the use of large endoprostheses
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A calcar collar is protective against early periprosthetic Femoral Fracture around cementless Femoral components in primary total hip arthroplasty: a registry study with biomechanical validation
'British Editorial Society of Bone & Joint Surgery', 2019Co-Authors: Jn Lamb, Baetz J, Messer-hannemann P, Bh ,van Duren, Redmond A, Rm West, Mm Morlock, Hg PanditAbstract:Aims The aim of this study was to estimate the 90-day risk of revision for periprosthetic Femoral Fracture associated with design features of cementless Femoral stems, and to investigate the effect of a collar on this risk using a biomechanical in vitro model. Materials and Methods A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic Fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an in vitro model using paired fresh frozen cadaveric femora. Results The prevalence of early revision for periprosthetic Fracture was 0.34% (1180/337 647) and 44.0% (520/1180) occurred within 90 days of surgery. Implant risk factors included: collarless stem, non-grit-blasted finish, and triple-tapered design. In the in vitro model, a medial calcar collar consistently improved the stability and resistance to Fracture. Conclusion Analysis of features of stem design in registry data is a useful method of identifying implant characteristics that affect the risk of early periprosthetic Fracture around a cementless Femoral stem. A collar on the calcar reduced the risk of an early periprosthetic Fracture and this was confirmed by biomechanical testing. This approach may be useful in the analysis of other uncommon modes of failure after THA
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a calcar collar is protective against early periprosthetic Femoral Fracture around cementless Femoral components in primary total hip arthroplasty a registry study with biomechanical validation
Journal of Bone and Joint Surgery-british Volume, 2019Co-Authors: Jn Lamb, J Baetz, P Messerhannemann, I Adekanmbi, B H Van Duren, Anthony C Redmond, Robert West, Michael M Morlock, Hg PanditAbstract:Aims The aim of this study was to estimate the 90-day risk of revision for periprosthetic Femoral Fracture associated with design features of cementless Femoral stems, and to investigate the effect...
Kyunghoi Koo - One of the best experts on this subject based on the ideXlab platform.
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frequency and associated factor of atypical periprosthetic Femoral Fracture after hip arthroplasty
Injury-international Journal of The Care of The Injured, 2018Co-Authors: Youngkyun Lee, Chan Ho Park, Ki Choul Kim, Seong Hwa Hong, Kyunghoi KooAbstract:Abstract Background Atypical Femoral Fracture (AFF) is a serious complication after the use of bisphosphonates, and periprosthetic Femoral Fracture (PFF) appeared as a common complication after hip arthroplasty, especially in senile patients. Although American Society for Bone and Mineral Research has excluded PFFs from the definition of AFFs, several case reports found PFF patients undergoing bisphosphonate treatment, have Fractures resembling AFF and the authors suggested that AFF can also occur in operated femurs after hip arthroplasty. To date, the frequency and risk factors of atypical PFF are unknown. The purpose of our study was (1) to evaluate the proportion of atypical PFF among Vancouver type B PFFs, and (2) to determine the association between occurrence of atypical PFF and use of bisphosphonate. Methods We reviewed medical records and radiographs of 67 Vancouver type B PFFs (67 patients) due to low-energy trauma and classified them into atypical PFF group and ordinary PFF group. We calculated the proportion of atypical PFFs among PFFs and identified risk factors for atypical PFF. Results Among the 67 PFFs, 7 Fractures (10.4%) were classified as atypical PFF. Longer duration of bisphosphonate use was an independent risk factor of atypical PFF. (Odds ratio 2.600, 95% CI 1.184–5.709, p = 0.017). Conclusion In accordance with wide use of bisphosphonate, atypical PFFs after hip arthroplasty are not rare anymore. Physicians should suspect the atypical PFF, when they meet low-energy Fracture in bisphosphonate users, and radiographs show features of AFF.
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incidence and risk period of periprosthetic Femoral Fracture after cementless bipolar hemiarthroplasty in elderly patients
Journal of Arthroplasty, 2016Co-Authors: Byungho Yoon, Youngkyun Lee, Daihai Choi, Kyunghoi KooAbstract:Abstract Background The purpose of this study was to investigate the periprosthetic Femoral Fracture (PFF) after cementless bipolar hemiarthroplasty incidence, noting Fracture types and the results of treatment in elderly patients. Methods We retrospectively reviewed 1563 elderly patients (1177 women and 386 men) who underwent cementless bipolar hemiarthroplasty for Femoral neck Fracture (1061 patients) or intertrochanteric Fracture (502 patients). The type of Fracture was classified according to the Vancouver classification. The average age was 79.6 years (range, 65-103 years). Clinical and radiologic evaluations were performed and Kaplan-Meier survivorship was analyzed. Results Thirty-seven PFFs (2.4%) occurred during a mean follow-up of 44.4 months. Two-thirds of PFFs (67%) occurred within 1 year. Most PFFs (22/27), which occurred within 2 years, were Vancouver type B Fractures. After that, type A Fractures were predominant (7/9). Based on Kaplan-Meier survivorship with PFF as the end point, the incidence rate was 1.7% (95% confidence interval [CI] = 1.6%-1.8%) at 12 months, 2.2% (95% CI = 2.1%-2.3%) at 36 months, and 3.8 % (95% CI = 3.6%-4.0%) at 144 months postoperatively. Conclusion After cementless bipolar hemiarthroplasty in elderly patients, a caution should be paid to prevent PFF particularly during 1-year postoperatively.
