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Purpose: Templating is the first step in achieving a successful total hip arthroplasty. We hypothesize that native head size is highly correlated with implanted cup size. Therefore, the purpose of this study is to look for a correlation between sizes of the intra-operative measurement of the femoral head and the implanted cup. Methods: This is a monocentric observational study conducted from December 2018 till January 2023. All patients admitted for a primary total hip arthroplasty were included and retrospectively reviewed. Intra-operative femoral head measurement, radiographic femoral head diameter, templated (planned) cup size, and definitive implanted cup size were recorded. Results: The sample included 154 patients (85 female and 69 males) with a mean age of 66.2 ± 10.4 years. There were 157 THA cases; 82 on the right side and 75 on the left side. The native head size and acetate template on digital radiographs were the most significantly positively correlated with cup size (P < 0.0001) while the radiological head size was significantly negatively correlated with cup size (P = 0.009). The implanted cup was on average 2 ± 2 mm bigger than the native head size measured intra-operatively. Conclusion: The native femoral head diameter measured intra-operatively is a simple and reliable tool to help the surgeons choose the proper size of the acetabular cup, preventing complications during surgery hence optimizing results post operatively. This technique would contribute to a more ecofriendly orthopaedic reconstructive surgery. [ABSTRACT FROM AUTHOR]

Introduction: Dual-mobility cups (DMC) are gaining popularity mainly for their reduced rate of dislocation following total hip arthroplasty (THA). Currently, indication for DMC use extends beyond patients with high risk of dislocation or revision THA cases. Many authors reported DMC outcomes in primary THA for all aetiologies. However, some reports claimed that the use of DMC is accompanied with higher rates of infection compared with conventional cups (CC) in both primary and revision THA. Research question: Does the use of DMC generate higher rates of infection when compared with conventional cups? Objectives: The aim of this meta-analysis was to look for significant difference in the rate of post-operative infection between DMC cups and conventional cups. Methodology: MEDLINE, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar were searched since inception. Only studies with comparative design reporting the outcome infection rate were included. Results: Seventeen retrospective comparative studies were located comprising 248,541 patients: 16,020 in the DMC group and 232,521 in the CC group. The mean follow-up period was 37.5 ± 42 and 50.2 ± 48.7 months for the DMC and CC groups, respectively. The meta-analytical results indicated the following: (a) significantly lesser infections following DMC compared with CC in revision THA (odds ratio (OR) = 0.75 (95% CI = 0.653 to 0.874, P = 0.0002, I2 = 25%); (b) for primary THA and for large-sampled registries, significance was found using only the fixed-effects model estimate; and (c) no significant difference was found for the subgroup of cohort studies. Conclusion: Our results clearly refute the claim that DMC would yield higher rates of infection. On the contrary, the findings demonstrated that the use of DMC reduces the risk of post-operative infection in revision THA and a similar lower infection trend for primary THA when compared with the standard cups. [ABSTRACT FROM AUTHOR]

Introduction: Using a cementless fixation for total knee arthroplasty (TKA) is controversial. We hypothesized that cementless tibial base plate with a monoblock long stem (MLS) would provide secure tibial alignment and stable fixation when bone conditions were considered as poor for a cementless fixation. The purpose of this study was to compare the mean eight year survivorship of cementless standard keels (SK) vs cementless MLS.Material Methods: We report a matched series of 98 cases of SK and 98 cases of MLS in patients with poor bone conditions. The two cohorts were statistically compared. Revision for tibial loosening was used as the endpoint in the survivorship analysis.Results: We recorded two cases of tibial loosening and three cases of bipolar loosening in the SK group (0% MLS vs 5% SK). No tibial loosening occurred in the MLS group (statistically significant). No tibial periprosthetic or intra-operative fractures occurred in either group. The survivorship at eight years of follow-up was 95.6% in the SS cohort vs 100% in the MLS cohort using revision for tibial loosening as the endpoint.Discussion: This study was not randomized. Its strength was that it took into account the comparative midterm outcomes of a matched cohort of patients implanted with two types of cementless components in the same bone conditions. We did not record any tibial loosening in the MLS group. Using long stems has been criticized but we did not observe any adverse reactions and no intra-operative tibial fracture occurred.Conclusion: MLS improves the alignment and fixation of cementless TKA. This is a safe solution when bone conditions are poor or modified by previous surgery. [ABSTRACT FROM AUTHOR]

Introduction: Since the first measurement method of patella height in 1929 (Janssen), more than 16 methods have been described. Most of these measures are not suitable to measure patella height after total knee arthroplasty (TKA). One of us (JC) modified the original Caton Deschamps (oCD), index with a new relative index called modified Caton Deschamps (mCD) index, by using new landmarks. The purpose of this study was to determine how patella height is modified after TKA.Material and Method: Sixty primary TKAs were consecutively prospectively enrolled. One type of implant was used (cementless postero-stabilized TKA, rotating plateau, cemented patella resurfacing). Patient's characteristics, functional and radiological outcomes were recorded pre-operatively and at one year follow-up. Pre-operative and post-operative outcomes were compared by paired t-test. Post-operative outcomes were compared between groups by one-way analysis of variance.Results: Average difference between pre and post-operative mCD was 0.19 in this series. In 81.7% of cases, patella was lowered. Patients were classified in three groups according to patella height lowering. Between these three groups, no significant statistical differences (IKS score knee and function, range of motion) could be identified.Discussion: In TKA, patella assessment in sagittal plane is as important as frontal or horizontal planes. True patella infera (TPI) is mostly due to patella tendon shortening measured by oCD. Pseudo patella infera (PPI) measured by mCD is mostly due to joint line elevation (over femoral cut with an over thickness of the tibial component). In this study a moderate patella lowering (minor than 15%) does not have a significant impact on the functional results (IKS, ROM) nevertheless in 80% patella is lowered. The next step will be to analyze precisely what factors are influencing this lowering and what prevention could be suggested in primary and revision TKA. [ABSTRACT FROM AUTHOR]

Purpose: Osteolysis in total hip arthroplasty (THA) depends on polyethylene wear and dictates the survival of the prosthesis. Dual mobility in THAs, which is claimed to reduce dislocation risk, has very good long-term clinical results. However, little is known about how the liner wears in this design, compared to the standard single mobility model.Methods: A comparative study looking at wear of a conventional ultra-high-molecular-weight polyethylene liner, using gravimetric measurement, between dual mobility implants and standard implants, was performed on a simulator in accordance with a normed protocol based on the same dimensions, environmental conditions and stresses. A linear regression test was employed.Results: Under the same conditions (loading, cycles, sterilization, material and surface roughness), the gravimetric wear (for conventional polyethylene) is comparable between a standard and a dual mobility cup. This correlates to ten year follow-up results of dual mobility cup.Discussion- Conclusion: This in vitro equivalent wear serves to confirm the very good long-term clinical results observed with dual mobility bearing, whose use should not be restricted by concerns about increased polyethylene wear. [ABSTRACT FROM AUTHOR]

Introduction: Low friction arthroplasty (LFA) introduced by Sir John Charnley was the gold standard for many years. Dislocation and infection are the first causes for early revision. Late failures are polyethylene (PE) wear and loosening. Due to dislocation risk we slowly switched to the use of LFA with dual mobility cups (DMC). The purposes of this study are (1) to assess whether our changes have improved outcomes and (2) what is the new gold standard?Material and Methods: We selected from an observational registry of 1,091 cases of hybrid Charnley total hip arthroplasty (THA). The acetabular component was either DMC in 455 cases or fixed cup (FC) in 636 cases.Results: Three dislocations (0.6%) occurred in the DMC group (none revised). In the FC group 54 dislocated (8.49%) and 20 were recurrent and underwent revision (revision rate 3.14%). In the DMC group, five acetabular and three femoral revisions were performed (revision rate for loosening 1.7%). In the FC group 19 cases underwent acetabular revision, and five cases had femoral component revised (revision rate for loosening 3.7%).Discussion: Charnley's LFA has proven over 50 years of excellent survivorship. To decrease dislocation risk, one suggested increasing femoral head diameter. Gilles Bousquet proposed another way, namely, the DMC concept. Dislocation is no longer a critical issue with DMC as demonstrated in our series and main series. DMC in primary THA is still a subject of debate. Mid-term results do not demonstrate a higher rate of wear than LFA. What is the current gold standard? LFA was and is our current gold standard in association with a DMC. [ABSTRACT FROM AUTHOR]

Introduction: The dual-mobility cup (DMC) was introduced in 1979. Due to lack of referenced publications, this interesting and innovating concept was ignored during close to 20 years. However, 180 studies (level III or IV) have now been published. Evidence-based medicine is based on level I studies. Over the past three decades, the role of national registries developed with the intention of surveying orthopaedic implants. In 2012, we developed, registered, and implemented a specific database for contemporary DMC.Material and Methods: Data are collected with an electronic case-report form, and this evaluation is limited to a single product line . From May 2012 to December 2016, 2090 cases of Quattro cup implantation have been registered; results of the first 636 primary cases with a minimum follow-up of three years were previously reported (series 1). Of the 1454 remaining cases, dislocation rate only was monitored (series 2) and results are reported here.Results: In series1 comprising 553 degenerative diseases and 83 proximal femoral fractures (PFF), one dislocation (1.2%) occurred in PFF and none in degenerative disease. Survivorship (infection excluded) at three years was 99.8%. In series 2 (1315 degenerative diseases; 139 PFFs), dislocation rate was 0.27% (four cases). In neither series did we observe any intraprosthetic dislocation.Discussion: Results of this private regional register confirm the high efficiency of DMC to decrease dislocation rate (0.23%). Few outcomes of DMC in primary total hip arthroplasty (THA) are published in national registries. The Swedish Hip Arthroplasty Register has reported on 287 primary DMC hips of 78,098 THAs. No dislocations were reported. We conclude that DMC decreases dislocation rate, and the national registry of Lithuania also reports a significant decrease in the rate of revision for dislocation in the DMC group. These data-available online-allow us to monitor DMC in real time, although they lack short-term follow-up. [ABSTRACT FROM AUTHOR]

Introduction: The causes for revision of primary total hip arthroplasty (THA) are various and quite well known. The developing use of dual-mobility THA (DM-THA) seems a relevant option to decrease the risk of instability. Due to lack of long-term follow-up, this innovative retentive concept is suspected to increase the risk of polyethylene (PE) wear. the aim of the study was to analyse the causes for DM-THA revision and assess whether or not its occurrence is different from that of fixed-standard (FS) THA , particularly for aseptic loosening or wear and/or osteolysis.Materials and Methods: The SoFCOT group conducted an observational prospective multicentre study from 1 January 2010 to 31 December 2011. Inclusion criteria comprised an exhaustive collection of 2044 first-revision THAs with 251 DM-THAs and 1793 FS-THAs. After excluding complications linked to patient factors (infection and periprosthetic fractures), we performed a matched case-control study (matching ratio 1:1) comparing two groups of 133 THAs.Results: Revisions for aseptic loosening or osteolysis/wear were as frequent in DM-THA (58.7 %) as in FS-THA (57.1 %) (p 0.32); 7.5 % of DM-THA were revised for dislocation versus 19.5 % of FS-THA (p 0.007).Discussion: Revision for osteolysis/wear and aseptic loosening were as frequent in DM-THA as in FS-THA; revision for dislocation was less frequent in DM-THA. This confirms the efficiency of the DM concept regarding the risk of dislocation. Causes for revision were different between groups, and revisions for dislocation were less frequent in DM-THA. Only prospective comparative studies could provide reliable information that may support broader use of the DM concept. [ABSTRACT FROM AUTHOR]

Introduction: We described in 1981 a method to evaluate patellar height in normal and symptomatic knees on sagittal X-ray view. This index is a frequently used method, yet it is not suitable after a total knee arthroplasty (TKA).Material and Method: The original method measures the distance between the distal margin of the articular surface of the patella (point A) and the anterosuperior angle of the tibial plateau (point T), then the length of the patellar articular surface (AP). The index is AT/AP ratio (normal values range from 0.8 to 1.2). After TKA, the T landmark is no longer available, so we must define a new T' landmark. This point is situated at the intersection between the line perpendicular to the tibial posterior cortex elevated at the tip of the fibular head and the tibial anterior cortex. This remarkable landmark can be identified before and after TKA, with a new relative index AT'/AP ratio. This modified method allows the comparison of patella height before and after TKA.Results: We have used this modified index with the collaboration of several authors during the testing of different models of TKA, with an accurate reproducibility. Repeatability (usually called intra-observer reliability) was good, with intra-class correlation coefficients (ICCs) between 0.58 and 0.75 among the observers. Reproducibility (usually called inter-observer reliability) was also considered as good, with ICC ranging from 0.64 to 0.72.Discussion: Patella height measurement has to be assessed with the original method (AT/AP) to detect patella infera that could influence the surgical approach. The correlation between original and modified indexes has to be assessed. The modification of patella height after TKA could be evaluated through the modified index and compared with functional results. [ABSTRACT FROM AUTHOR]

Purpose: The dual mobility cup introduced in France by Gilles Bousquet has been used in total hip replacement in high-risk patients. This device acts as a large ball implant and significantly reduces the risk of dislocation following hip arthroplasty. Published French literature has focused on low rates of dislocation and long-term follow-up similar to the low-friction arthroplasty. Methods: We retrospectively reviewed a continuous series of 105 cases of dual mobility cup Quattro (Groupe Lépine, Genay, France) implanted from 2000 to 2002. Selection of the patients requiring a primary hip replacement depended on risk criteria such as age, hip disease and activity score. The dual mobility cup was associated with a modular cemented femoral component and a 22.2-mm stainless steel head. Results: One dislocation occurred one month after the index surgery requiring no revision surgery. According to the Kaplan-Meier method, survival probability was 95.0 % (95 % confidence interval 81.5–98.8) at ten years of follow-up. Conclusions: Based on clinical outcome and patient assessment we conclude that the dual mobility cup is a reliable option to decrease dislocation risk without increasing polyethylene wear. [ABSTRACT FROM AUTHOR]

Use of a dual-mobility acetabular cup is associated with a lower risk of dislocation compared with conventional hip implants. The seleXys® DS acetabular cup combines the advantages of Charnley low-friction arthroplasty with those of dual mobility. We performed a non-randomised, prospective study of patients receiving primary hip arthroplasty, including an uncemented seleXys® DS dual-mobility acetabular cup with hydroxyapatite coating (Mathys AG, Bettlach, Switzerland) and a cemented femoral component (Stallion femoral stem Groupe Lepine, Lyon, France). The objective of the study was to evaluate longevity of the implant and the risk of dislocation. All operations were performed by a single surgeon using a posterior approach, with patients lying in the lateral decubitus position. The stem had a modular head diameter of 22.2 mm and was cemented in all patients. A total of 53 patients were studied, and the median duration of follow-up was 78.9 months. Implant survival 6 years after surgery was 98.4% (n=47; 95% CI: 89.3-99.8). There was one revision for sepsis 29 months after surgery, and one dislocation. The results of this study appear to demonstrate excellent implant survival and a low rate of dislocation using the chosen implants. [ABSTRACT FROM AUTHOR]

Background: Since 1962, the low friction arthroplasty (LFA) developed by Sir John Charnley has spread widely throughout the world. Many series have reported long-term results. Polyethylene (PE) wear is well known. The average wear ratio is about 0.1 mm a year. Many factors may influence that wear process. Purpose: The authors describe two different series of patients operated upon with Charnley's total hip arthroplasty (THA) using the original cemented stem and a non modular 22.2-mm head, with a cemented full polyethylene acetabular socket. Outcomes confirm excellent patient function after 25 years. They emphasise the fact that PE is the weak point of total hip arthroplasty. Function may be excellent even though PE wear is significant. In several cases, no wear at the maximum follow-up was detectable. Results: This study confirms different publications relating long-term follow-up with LFA. During a Charnley meeting in Lyon, we published a survival curve of 85% after 25 years. Berry et al. published a 86.5% survival curve (J Bone Joint Surg Am 84:171-177, 2002). In 1995, Luc and Marcel Kerboul published a 77% survival rate after 20 years in young patients under 40 years old at the time of the surgery. In 2009, Callaghan et al. published a series of 35 years follow-up with a ratio of 78% survivorship (J Bone Joint Surg Br 91:2617-2621). Conclusion: Could the long-term results be improved? Through recent decades, many solutions have been introduced to improve the survivorship of THA including bearing surfaces such as alumina-on-alumina and metal-on-metal. Different problems have occurred with these solutions. LFA might be improved by working on the nature and the quality of the head. Improvements might also be obtained by working on the quality and the hardness of the acetabular socket. [ABSTRACT FROM AUTHOR]

Revision of large-diameter, monoblock acetabular components for both hip resurfacing arthroplasty and metal-on-metal (MoM) total hip arthroplasty (THA) is correlated to a high amount of complications. For this reason, performing a limited revision by conversion to a dual mobility (DM) without acetabular component exchange has been proposed in order to limit these complications. Although DM bearing offers an easy solution avoiding the intraoperative and time-associated complications, concern about polyethylene wear and stability remains due to the difference regarding the design, the coverage angle and the clearance of the two implants. In order to evaluate the performance of this new solution with the new material to prevent the possibility of failure it is essential to conduct a review of the literature A qualitative systematic review of the literature has been conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search of PubMed, EMBASE, Google Scholar, and Scopus for English and French articles between January 2000 and October 2019 was performed, with the primary objective of finding articles about dual mobility bearing coupling with large metal-on-metal cup in the case of hip revision procedure. Various combinations of the key words were used in the search strategy. Thirteen articles with DM bearing mated with MoM cup were analyzed. Of the 130 hip revisions selected, with a follow-up from 6 to 53 months, there were a total of 14 with complications (10.77%): four true dislocations (3.08%); six intra-prosthetic dislocations (IPD, 4.6%), two of which presented plastic deformation and polyethylene wear; four other complications (3.08%), included a cup osteolysis, a clicking noise, a superficial infection and a periprosthetic fracture. All the mentioned true dislocations occurred during the first month while IPDs appeared during the first two years from the index revision. In conclusion, according to the literature analyzed, we can stress that the concerns and doubts about mating a DM bearing with large MoM cup cannot be dissolved. It has been pointed out that a DM bearing is not designed for a MoM cup; it is not mechanically tested on MoM cups, which presents different clearance and coverage angles. Predictable complications may occur, such as IPD, polyethylene wear and true dislocation. These complications have been reported at an even higher rate than they were in the eighties, when the first generation of DM implants were of a lower quality of polyethylene and the characteristic of the design was less optimal than modern ones. [ABSTRACT FROM AUTHOR]