Objectives. To examine mortality and revision rates among patients with osteoarthritis undergoing hip arthroplasty and to compare these rates between patients undergoing cemented or uncemented procedures and to compare outcomes between men undergoing stemmed total hip replacements and Birmingham hip resurfacing. Main outcome measures. Hip arthroplasty procedures were linked to the time to any subsequent mortality or revision (implant failure). Flexible parametric survival analysis methods were used to analyse time to mortality and also time to revision. Comparisons between procedure groups were adjusted for age, sex, American Society of Anesthesiologists (ASA) grade, and complexity. Results. Multivariable survival analyses identified a higher mortality rate for patients undergoing cemented compared with uncemented total hip replacement (adjusted hazard ratio 1.11, 95% confidence interval 1.07 to 1.16); conversely, there was a lower revision rate with cemented procedures (0.53, 0.50 to 0.57). These translate to small predicted differences in population averaged absolute survival probability at all time points. For example, compared with the uncemented group, at eight years after surgery the predicted probability of death in the cemented group was 0.013 higher (0.007 to 0.019) and the predicted probability of revision was 0.015 lower (0.012 to 0.017). In multivariable analyses restricted to men, there was a higher mortality rate in the cemented group and the uncemented group compared with the Birmingham hip resurfacing group. In terms of revision, the Birmingham hip resurfacings had a similar revision rate to uncemented total hip replacements. Discussion. There is a small but significant increased risk of revision with uncemented rather than cemented total hip replacement, and a small but significant increased risk of death with cemented procedures. It is not known whether these are causal relations or caused by residual confounding. Compared with uncemented and cemented total hip replacements, Birmingham hip resurfacing has a significantly lower risk of death in men of all ages. Previously, only adjusted analyses of hip implant revision rates have been used to recommend and justify use of cheaper cemented total hip implants. Our investigations additionally consider mortality rates and suggest a potentially higher mortality rate with cemented total hip replacements, which merits further investigation. These results have now been confirmed by other Centres as well. [1,2] Our findings agree with those of Kendal et al who confirm that those undergoing metal-on-metal hip resurfacing have reduced mortality in the long term (up to 10 years) compared with those undergoing total hip replacement and that this difference persisted after extensive adjustment for confounding factors. Although residual confounding is possible, the observed effect size is large

Source of the study: University of Auckland, Auckland, New Zealand. Unicompartmental knee arthroplasty (UKA) is effective for patients with isolated compartment osteoarthritis, however the procedure has higher revision rates. Long-term survivorship and accurate characterisation of revision reasons are limited by a lack of long-term data and standardised revision definitions. We aimed to identify survivorship, risk factors and revision reasons in a large UKA cohort with up to 20 years follow-up. Patient, implant and revision details were recorded through clinical and radiological review for 2,137 consecutive patients undergoing primary medial UKA across Auckland, Canterbury, Counties Manukau and Waitematā DHB between 2000 and 2017. Revision reasons were determined from review of clinical, laboratory, and radiological records for each patient using a standardised protocol. To ensure complete follow-up data was cross-referenced with the New Zealand Joint Registry to identify patients undergoing subsequent revision outside the hospitals. Implant survival, revision risk and revision reasons were analysed using Cox proportional-hazards and competing risk analyses. Implant survivorship at 15 years was comparable for cemented fixed-bearing (cemFB; 91%) and uncemented mobile-bearing (uncemMB; 91%), but lower for cemented mobile-bearing (cemMB; 80%) implants. There was higher incidence of aseptic loosening with cemented implants (3–4% vs. 0.4% uncemented, p<0.01), osteoarthritis (OA) progression with cemMB implants (9% vs. 3% cemFB/uncemMB; p<0.05) and bearing dislocations with uncemMB implants (3% vs. 2% cemMB, p=0.02). Compared with the oldest patients (≥75 years), there was a nearly two-fold increase in risk for those aged 55–64 (hazard ratio 1.9; confidence interval 1.1-3.3, p=0.03). No association was found with gender, BMI or ASA. Cemented mobile-bearing implants and younger age were linked to lower implant survivorship. These were associated with disease progression and bearing dislocations. The use of cemented fixed-bearing and uncemented mobile-bearing designs have superior comparable long-term survivorship

Introduction. Osseointegration has emerged as a promising alternative to rehabilitating with a traditional socket mounted prosthesis. Advantages have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and better gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Several systematic reviews have indicated that the occurrence of minor infections can be quite common, serious complications are reported to be rare. In addition to commonly anticipated complications including fractures, surgical debridements or revisions, we have identified several significant events in which a patient may require to be readmitted and go through additional surgery. The objective of this study is to examine the rate of occurrence and reports on the best management practices of serious complications across a multi-centre review of more than 1000 osseointegration surgeries. Materials & Methods. A detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates between since 2010. The majority of surgeries took place in Australia, the United States, the Middle East as well as in Europe. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of implants, periprosthetic fracture fixation, surgical debridement due to infections, neurectomies and soft- tissue refashioning. Results. Over 800 surgeries have been identified with a minimum 12-month follow-up time and included in this study. These included tibial, femoral and humeral, radial-ulnar and transpelvic osseointegration cases. The majority of these were performed using a single stage protocol. While general complications such as infection and soft tissue refashioning are common, serious events such as revision and fracture are rare. Interestingly, the rate of debridements and soft-tissue refashions were found to be higher among patients who were operated using a two-stage surgery. Among all cases, there were a total of 399 re-operation events recorded which occurred among 163 patients, indicating a high recurrence rate among the same patients. We recorded a total of 112 washouts, 93 neurectomies, 117 soft tissue refashions, 53 implant revisions and 24 periprosthetic fracture fixations. Conclusions. Many events leading to readmission after the primary surgery may not necessarily be graded as a complication of the osseointegration technique. This study has identified several addition possible reasons in which an osseointegration patient may need to be re-admitted into hospital for additional surgery. It was identified that through the implementation of improved surgical techniques and rehabilitation protocols, the rate of several of these re-operation events can be largely reduced, thus improving the overall outcomes of patients undergoing osseointegration surgery

Introduction. Osseointegration has been established as a promising approach for the reconstruction of amputated limbs, particularly for amputees suffering from traditional socket prosthesis (TSP). While Osseointegration was originally developed with a screw fixation design, several Osseointegration devices adopting a modern press-fit design have also been introduced. In this study, medium-term outcomes for patients with the two most common press-fit osseointegration implant used worldwide are analysed. Materials and Methods. This is a cross-sectional analysis containing a cohort of Osseointegration patients treated in several centres worldwide. We analyzed a total of 93 patients with an average follow-up time of 6.52 years. Functional, Mobility and patient reported outcomes were collected pre-operatively and during follow-up. All postoperative adverse events (infection, revision surgery, fractures, and implant failures) were also analyzed. Results. Crude analysis of the data indicated that all 93 patients continue to use their osseointegrated prosthesis. Significant improvements for all outcome measures were observed. However, several adverse events including 19 implant revisions, 8 periprosthetic fractures and 43 surgical debridements were also reported. A detailed analysis was performed on each adverse event type to evaluate possible causes. Conclusions. At 5 years post-surgery, Osseointegration continues to provide amputees with improvements on function and quality of life which were previously unattainable with socket prosthesis. However, the benefits are accompanied with a relatively high risk of adverse events. Further research in standardizing clinical practice and the development of better implant may offer a reduction to these risks

Introduction. Advantages of osseointegration have been reported to include improved functional mobility, better osseoperception, improved comfort, reduced pain, better biomechanical alignment and gait, which all lead to a less restricted lifestyle and significantly improved quality of life. A major concern of the Osseointegrated approach lies in the risk of infections occurring from the permanent transcutaneous opening often referred to as the stoma. Materials and Methods. Detailed analysis has been performed on all osseointegration surgeries performed by the Osseointegration Group of Australia and it's affiliates since 2010. All events leading to a re-admission and subsequent re-operation have been identified through hospital operation records and pooled together for meta-analysis. Events identified include: revision of implants, periprosthetic fracture fixation, surgical debridement due to infections, neurectomies and soft- tissue refashioning. Results. Majority of these cases were performed following the single-stage protocol. Among all cases, there were a total of 399 re-operation events recorded which occurred among 163 patients, indicating a high recurrence rate among the same patients. We recorded a total of 112 washouts, 93 neurectomies, 117 soft tissue refashions, 53 implant revisions and 24 periprosthetic fracture fixations. Conclusions. In this study, we have identified several addition possible reasons in which an osseointegration patient may need to be re-admitted into hospital for additional surgery. It was identified that through the implementation of improved surgical techniques and rehabilitation protocols, the rate of several of these re-operation events can be largely reduced, thus improving the overall outcomes of patients undergoing osseointegration surgery

THA in patients with acetabular bone defects is associated with a high risk of dislocation. Dual mobility (DM) cups are known to prevent and treat chronic instability. The aim of this study was to evaluate the dislocation rate and survival of jumbo DM cups. This was a retrospective, continuous, multicenter study of all the cases of jumbo DM cup implantation between 2010 and 2017 in patients with acetabular bone loss (Paprosky 2A: 46%, 2B: 32%, 2C: 15% and 3A: 6%). The indications for implantation were revisions for aseptic loosening of the cup (n=45), aseptic loosening of the femoral stem (n=3), bipolar loosening (n=11), septic loosening (n=10), periprosthetic fracture (n=5), chronic dislocation (n=4), intraprosthetic dislocation (n=2), cup impingement (n=1), primary posttraumatic arthroplasty (n=8), and acetabular dysplasia (n=4). The jumbo cups used were COPTOS TH (SERF), which combines press-fit fixation with supplemental fixation (acetabular hook, two superior flanges with one to four screws, two acetabular pegs). A bone graft was added in 74 cases (80%). The clinical assessment consisted of the Harris hip score. The primary endpoint was surgical revision for aseptic acetabular loosening or the occurrence of a dislocation episode. In all, 93 patients were reviewed at a mean follow-up of 5.3 ± 2.3 years [0, 10]. As of the last follow-up, the acetabular cup had been changed in five cases: three due to aseptic loosening (3.2%) and two due to infection (2.1%). The survivorship free of aseptic loosening was 96.8%. Three patients (3%) suffered a dislocation. At the last follow-up visit, the mean HSS scores were 72.15, (p < 0.05). Use of a jumbo DM cup in cases of acetabular bone defects leads to satisfactory medium-term results with low dislocation and loosening rates

Background. The duration and extent of postoperative wound leakage after joint arthroplasty in patients with or without a complicated course, like a prosthetic joint infection (PJI), is currently unknown. Adequate differentiation between normal postoperative wound leakage and wound leakage due to a postoperative PJI is important and prevents unnecessary surgical procedures. We investigated the association between postoperative wound leakage and development of PJI in patients who used a previously developed mobile wound care app. Methods. A multicenter, prospective cohort study with patients aged 18 years or older after primary implantation or revision of a total joint arthroplasty. During 30 post-operative days after arthroplasty, patients recorded their wound status in the woundcare app. An algorithm calculated a daily score from imputed data. If the daily score exceeded a predefined threshold, the patients received an alert that advised them to contact their physician. Results. Of 1020 included patients from 11 centers, 14 patients developed a PJI. Of 1006 patients without PJI, any form of postoperative wound leakage occurred in 51%, 12%, 7% and 3% during the 1. st. , 2. nd. , 3. rd. and 4. th. postoperative week, respectively. Median duration of wound leakage was eight days (IQR 3.5–12.5) for patients with PJI and two days (IQR 0–4) for patients without PJI (p <0.001). In total, 498 (49%) patients received 2589 alerts. Receiving an alert was not predictive for the development of a PJI. The odds ratio for a PJI was higher in patients with wound leakage compared to patients without wound leakage: OR 1.76 (0.59–5.29), OR 45.42 (10.04–205.53), OR 16.76 (3.68–76.28) and OR 18.09 (1.59–205.66) in the 1. st. , 2. nd. , 3. rd. and 4. th. postoperative week, respectively. Conclusion. In patients who received a knee or hip arthroplasty, the odds ratios for PJI were significantly increased in patients with postoperative wound leakage. However, the high absolute number of patients with wound leakage and no PJI showed that wound leakage alone is not a sensitive, i.e. discriminative, indicator to guide the decision whether to reoperate patients for a suspected PJI. The abstract was submitted on behalf of the Woundcare app study group: H.M.J. van der Linden, Leiden University Medical Centre; D. Broekhuis, Leiden University Medical Centre; M. de Jong, Leiden University Medical Centre; M.R. Benard, Alrijne Hospital; A.P. Wassenaar, Alrijne hospital; A.S.B. Mol, Alrijne Hospital; M. Rutgers, Reinier Haga Orthopedic Center; J.Pasma, Reinier Haga Orthopedic Center; R. Bazuin, Reinier Haga Orthopedic Center; N. Mathijssen, Reinier Haga Orthopedic Center; C.E. Van Der Wijngaart, Onze Lieve Vrouwe Gasthuis; N.W. Willigenburg, Onze Lieve Vrouwe Gasthuis; M.E. Van Der Hoorn, Onze Lieve Vrouwe Gasthuis; B. Dijkstra, Medical Center Leeuwarden; L.D. De Jong, Rijnstate Hospital; H. Haan, University Medical Centre Groningen; M. Stevens, University Medical Centre Groningen; M. Reijman, Erasmus Medical Centre Rotterdam; H. Hoogeboom, Nijsmellinghe Medical Centre; C. Meijer, Park Medical Centre + all authors listed above this article

Chronic extensor mechanism insufficiency around TKA is a very challenging pathology to treat. An insufficient extensor mechanism negatively affects implant survival and patient outcomes. There are several risk factors for extensor mechanism disruption and the surgeon should be aware and avoid these problems in the perioperative period. In appropriately selected patients, reconstruction of the extensor mechanism is a valid option. Whole extensor mechanism and Achilles tendon allograft reconstruction of the deficient extensor mechanism have been proposed with good early published results. These reconstructions, however, are expensive and with time may stretch and lead to recurrence of an extensor lag. An alternative to allograft, is the use of Marlex mesh as popularised by Browne and Hanssen. This technique uses a knitted monofilament polypropylene mesh that is secured to the patient's native lateral tissue and covered by an appropriately dissected and distalised vastus medialis muscle. The technique can be used for both patellar and quadriceps tendon deficiencies and can be done with or without implant revision and is currently the treatment of choice at the presenter's institution. The surgeon should be aware of the complexity and limitations of these three reconstructive techniques

INTRODUCTION. In the United States, the Centers for Medicare and Medicaid Services consider rates of unplanned hospital readmissions to be indicators of provider quality. Understanding the common reasons for readmission following total joint arthroplasty will allow for improved standards of care and better outcomes for patients. The current study seeks to evaluate the rates, reasons, and Medicare costs for readmission after total hip and total knee arthroplasty. METHODS. This study used the Limited Data Set (LDS) from the Centers for Medicare and Medicaid Services (CMS) to identify all primary, elective Total Knee Arthroplasties (TKA) and Total Hip Arthroplasties (THA) performed from January 2013 through June 2016. The data were limited to Diagnosis-Related Group (DRG) 470, which is comprised of major joint replacements without major complications or comorbidities. Readmissions were classified by corresponding DRG. Readmission rates, causes, and associated Medicare Part A payments were aggregated over a ninety-day post-discharge period for 804,448 TKA and 409,844 THA. RESULTS. There were 31,172 readmissions in the ninety days following THA, for a readmission rate of 7.6%. There were 51,768 readmissions following TKA, for a readmission rate of 6.4%. The leading causes of readmission post-THA were revision of hip or knee replacement (17.66%); septicemia (4.76%); and postoperative infections (3.74%). The most common reasons for readmission post-TKA were postoperative infections (6.42%); septicemia (4.84%); and esophagitis (3.85%). In contrast to THA, implant revisions only accounted for 2.51% of readmissions after TKA. The mean cost of readmission post-THA was $11,682, while the mean cost of readmission post-TKA was $8,955. DISCUSSION AND CONCLUSION. Ninety-day readmission rates for both THA and TKA remained stable for the duration of the study period, suggesting the need for additional research on the efficacy of various programs intended to reduce the incidence of readmission

The interest in osteolysis has waned largely due to the impact of crosslinked polyethylene and the “rarity” of this phenomenon. However, the basic process still remains: particles, motion observed with unstable implants and host specific factors all play a role in bone loss around implants. There are 2 predominant patterns of lysis: Linear versus Expansile. Linear Lysis: is focal bone loss at the interface as seen in the bone cement interface in when using acrylic or at the implant-host interface with porous ingrowth/ongrowth implants. Expansile Lysis: is observed in less contained regions such as the retro- and supra-acetabular regions around the socket. These lesions can also be quite extensive yet may be subtle in appearance. Imaging is essential in identifying the extent and magnitude of osteolysis. Available modalities include plain radiographs although they can be of limited value in that even with oblique views, they often underestimate the degree of bone loss. CT scans are useful but can be limited by artifact. Several centers have explored the role of MRI in assessing lysis. It can be useful for bone loss and provides excellent assessment for soft tissue: abductors, neurovascular structures. Metal artifact reduction sequencing is required to maximise information obtainable. Management of osteolysis: Identification and monitoring periprosthetic osteolysis is a crucial element of patient care. Progressive bone loss leading to loss of fixation and the potential risk for periprosthetic fracture is a real possibility and early recognition and intervention is a priority. The basic Guiding Principles of management are centered around several key elements including the source of osteolysis and degree, the fixation of implant, the location of lysis, the track record of implant system, the presence of patient symptoms (if any), and finally the patient age, activity level, and general health. Specifics of treatment of osteolysis around the acetabulum: With cemented sockets, lysis is typically seen late and frequently at the bone-cement interface. It is often associated with a loose implant and the prime indication for surgery may be pain. Treatment involves implant removal and revision with an uncemented cup and bone grafting or augmentation as needed. With uncemented sockets in the setting of osteolysis, there are several factors to consider. These have been stratified by Rubash, Maloney, and Paprosky. The treatment of these sockets has been summarised as follows: for Type I and Type II with limited lysis, lesional treatment such as debridement and bone grafting with head and polyethylene exchange has been suggested. WATCH for impingement!!!! Graft defects via trap-doors can be performed but make the door big enough to graft. Small doors and grafting through screw holes is at best marginal. In instances of compromised locking mechanisms, consider cementing the liner into the shell. For Type II and Type III implants, revision of the component is recommended. With the currently available cementless cup extraction tools, I rarely hesitate to remove a cup with moderate lysis and a broken locking mechanism: better access to lytic areas, better grafting achieved. CAVEAT #1: the disadvantage of implant removal is that it is clearly a bigger procedure and fixation of the new implant may be more difficult. Risks vs. rewards. CAVEAT #2: Socket revision in the setting of failed MOM implants has some unique “issues”. In the Vancouver series, almost 25% of the revision cups failed to achieve biologic fixation. As such, recommendation for using “enhanced” porous implants during revision seems prudent. Additionally, despite the use of larger diameter heads, instability rates remain high

Introduction. National Institute for Health and Clinical Excellence (NICE) guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractured neck of femur (NOF) in cognitively intact patients who were independently mobile prior to the injury. The National Joint Registry for England and Wales (NJR) has collected data on THRs performed since 2003. This retrospective cohort study explores risk factors independently associated with implant failure and perioperative mortality. Methods. NJR data recording a THR performed for acute fractured NOF between 2003 and 2010 were analysed. Cox proportional hazards models were used to analyse the extent to which risk of implant revision was related to specific covariates. Multivariable logistic regression was used to analyse factors affecting 90-day perioperative mortality. Significance was taken as p< 0.01. Result. A total of 4495 procedures were analysed, of which 83 (1.9%) underwent revision surgery and 144 (3.2%) patients died within 90 days. Increased risk of implant revision was associated with the use of cementless prostheses (Hazard Ratio [HR]=2.23, p=0.001), but revision risk was independent of age, American Society of Anaesthesiologists (ASA) grade, gender, head size and head material. Risk of mortality within 90 days was significantly associated with high ASA (grade 3: Odds ratio [OR]=7.20, p< 0.001, grade 4/5: OR=38.09, p< 0.001, referenced to grade 1 group) and older age (≥81 years: OR=2.04, p=0.004, referenced to 60–70 years group). Mortality risk was lower in patients who had a hybrid THR (OR=0.51 p=0.004), after risk adjustment. Conclusion. There is considerably greater risk of implant revision when cementless THR is used for managing fractured NOF. Risk of perioperative mortality is greatest in patients over 80 years with ASA grades 3 or above, and lowest with hybrid THR. This information may be used to guide the surgical management of patients with fractured neck of femur

INTRODUCTION. Historically, the clinical performance of novel implants was usually reported by designer surgeons who were the first to acquire clinical data. Regional and national registries now provide rapid access to survival data on new implants and drive ODEP ratings. To assess implant performance, clinical and radiological data is required in addition to implant survival. Prospective, multi-surgeon, multi-centre assessments have been advocated as the most meaningful. We report the preliminary results of such a study for the MiniHip™femoral component and Trinity™ acetabular component (Corin Ltd, UK). METHODS. As part of a non-designer, multi-surgeon, multi-centre prospective surveillance study to assess the MiniHip™stem and Trinity™ cup, 535 operations on 490 patients were undertaken. At surgery, the average age and BMI of the study group was 58.2 years (range 21 to 76 years) and 27.9 (range 16.3 to 43.4) respectively. Clinical (Harris Hip Score, HHS) and radiological review have been obtained at 6 months, 3 and 5 years. Postal Oxford Hip Score (OHS) and EuroQol- 5D (EQ5D) score have been obtained at 6 months and annually thereafter. To date, 23 study subjects have withdrawn or lost contact, 11 have died, and 9 have undergone revision surgery. By the end of March 2018, 6 month, 1, 2, 3, 4, and 5 year data had been obtained for 511, 445, 427, 376, 296 and 198 subjects respectively. RESULTS. Implant revision rate is 1.68% (9/535), with revision for any reason as an endpoint; four of the nine involved the revision of the femoral component. At the 5-year time point, mean OHS had improved from 21.3 to 42.5 (p<0.01), EQ5D from 0.42 to 0.82 (p<0.01), and HHS from 51.6 to 92.5 (p<0.01). Radiological analysis is ongoing, and thus far has revealed more variation in stem alignment than is usually observed for more conventional length femoral components. This may indicate that optimal alignment of calcar loading short stems is different to that of longer, medullary canal aligned implants, consistent with the neck-stabilised design of the MiniHip™ stem. No other significant radiological findings were noted. During surgery, 31 calcar fractures were sustained, of which 20 were treated with cerclage wiring, 1 with femoral grafting and the remainder required no treatment. None of the hips with calcar fractures have been revised to date. DISCUSSION. The clinical and radiological performance of the MiniHip™ femoral stem is consistent with established femoral implants. Longer surveillance will determine whether this performance is maintained. Patients in this study will be continued to be followed-up and reviewed at the 7 and 10-year time points. CONCLUSION. The MiniHip™ stem is safe and efficacious at mid-term follow-up

Endoprosthetic replacement (EPR) is an available option for the management of massive bone loss around failed knee implants. The aim of this study was to determine the results of knee EPRs performed for non-tumour indications. Since 2007, 85 EPRs were performed for in a single tertiary centre by seven surgeons. Mean age at surgery was 73.5 years (range:35–95) with infection as the most common indication (49%), followed by aseptic loosening (18%), complex primary replacement (16%), fracture (15%) and mechanical failure (2%). Mean follow up was 4 years (range:1–9). Functional outcome was determined using the Oxford Knee Score (OKS). At follow-up, 21 patients were deceased and 2 lost to follow-up. Complication rate was 19%. Of the 7 infected cases, 6 were treated with DAIR (debridement, antibiotics, and implant retention) and one underwent above knee amputation. Four of the patients undergoing DAIR were cleared of infection and 2 are on long-term antibiotics. Accounting for implant revision, loss to follow-up and those on long-term antibiotics as failures, 5-year survival was 89% with an average OKS of 25 (SD=10). This mid-term study shows that distal femur EPR is a valuable option for the increasing burden of complex revision knee surgery

Aim. Diagnosis of periprosthetic joint infection (PJI) is challenging given the limitations of available diagnostic tests. Recently, several studies have shown a role of the long pentraxin PTX3 as a biomarker in inflammatory diseases and infections. This single-center prospective diagnostic study evaluated the diagnostic ability of synovial fluid and serum PTX3 for the infection of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Method. Consecutive patients undergoing revision surgery for painful THA or TKA were enrolled. Patients with antibiotic therapy suspended for less than 2 weeks prior to surgery and patients eligible for metal-on-metal implant revision or spacer removal and prosthesis re-implantation were excluded. Quantitative assessment of synovial fluid and serum PTX3 was performed with ELISA method. Musculoskeletal Infection Society (MSIS) criteria were used as reference standard for diagnosis of PJI. Continuous data values were compared for statistical significance with univariate unpaired, 2-tailed Student's t-tests. Receiver operating characteristic (ROC) curve analyses was performed to assess the ability of serum and synovial fluid PTX3 concentration to determine the presence of PJI. Youden's J statistic was used to determine optimum threshold values for the diagnosis of infection. Sensitivity (Se), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (LR+) and negative (LR-) likelihood ratio, area under the ROC curve (AUC) were calculated. Results. One-hundred fifteen patients (M:F=49:66) with a mean age of 62 years (40–79) underwent revision of THA (n=99) or TKA (n=16). According with MSIS criteria, 18 cases were categorized as septic and 97 as aseptic revisions. The average synovial fluid concentration of PTX3 was significantly higher in patients with PJI compared to patients undergoing aseptic revision (24,3 ng/dL vs 3,64 ng/dL; P=0.002). There was no significant difference in terms of serum concentration of PTX3 between the two groups. Synovial fluid PTX3 demonstrated an AUC of 0.96 (95%IC 0.89–0.98) with Se 94%, Sp 90%, PPV 67%, NPV 100%, LR+ 9.4 and LR- 0.06 for a threshold value of 4.5 ng/dL. Serum PTX3 demonstrated an AUC of 0.70 (95%IC 0.51–0.87) with Se 72%, Sp 67%, PPV 30%, NPV 93%, LR+ 2.2 and LR- 0.42 for a threshold value of 4.5 ng/dL. Conclusions. In patients undergoing revision surgery for painful THA or TKA, synovial PTX3 demonstrated a strong diagnostic ability for PJI. Synovial PTX3 could represent a more useful biomarker for detection of PJI compared with serum PTX3

Background. Periprosthetic joint infection (PJI) after knee arthroplasty surgery remains a serious complication. Yet, there is no international consensus on the surgical treatment of PJI. The purpose was to assess the prosthesis survival rates, risk of re-revision, and mortality rate following the different surgical strategies (1-stage or 2-stage implant revision, and irrigation and debridement (IAD) with implant retention) used to treat PJI. Methods. The study was based on 653 total knee arthroplasties (TKAs) revised due to PJI in the period 1994 to 2016. Kaplan-Meier (KM) and multiple Cox regression analyses were performed to assess the survival rate of these revisions and the risk of re-revisions. We also studied the mortality rates at 90 days and 1 year after revision for PJI. Results. Of the 653 revision TKAs; 329, 81, and 243 revisions were performed with IAD, 1-stage, and 2-stage revision procedures, respectively. During the follow-up period, 19%, 12.3% and 11.5% of the IAD, 1-stage, and 2-stage revision cases were re-revised due to PJI, respectively. With any reasons of re-revision as end-point the 5 year KM survival of the index revision procedure was 76%, 82%, and 84% after IAD, 1-stage, and 2-stage revision, respectively. Similarly, the 5-year KM survival with a re-revision for infection as end-point was 79%, 88%, and 87% after IAD, 1-stage, and 2-stage revision, respectively. There were no statistically significant differences between 1-stage and 2-stage revision for re-revision of any reasons (RR=1.6; 95% CI: 0.8–3.1) nor did we find a difference for re-revision due to deep infection (RR=1.4; 95% CI: 0.6–3.1) as end-point. In an age-stratified analysis, however, the risk of re-revision for any causes was 4 times increased after 1-stage revision compared to 2-stage revision in patients over 70 years of age (RR=4.2, 95% CI: 1.3–13.7) but the risk was similar for deep infection as end-point. Age had no statistically significant effect on the risk of re-revision for knees revised with the IAD procedure. The 90-days and 1-year mortality rate after revision for PJI were 2.1% and 3.6% after IAD, 1.2% and 1.2% after 1-stage revision, and 0.4% and 1.6% after 2-stage revision and there were no statistically significant differences in mortality rate according to revision procedure. Conclusion. IAD had good results compared to earlier published studies. Despite that 1-stage revisions had a 4 times higher risk for re-revision compared to 2-stage revisions in older patients, the overall outcomes after 1-stage and 2-stage revision were similar

Dislocation and instability remain leading cause of failure following THA. We present a single-surgeon 10-year experience with use of Dual Mobility (DM) bearings in Primary and Revision THA using posterior approach. 127 DM bearings were implanted between September 2006 – September 2016; 102 in high-risk primary THA's and 25 revision THA's for either treatment or prevention of instability. Selection for DM bearing followed individual patient risk assessment. Criteria for use of DM bearing were presence of multiple risk factors. Mean age was 72.9 years. 100 Mono-block DM implants, 22 Modular DM implants and 5 custom-made DM devices were implanted. Revision cohort included those used in conjunction with a cage or porous metal augments. 2 dislocations (1.6%) were observed, both in the Revision group, 1 was recurrent requiring revision to constrained liner. Primary group had 2 revisions; 1 peri-prosthetic fracture and 1 deep infection. No DM bearing specific complications were observed. A constructed life table calculated survival function with endpoint set as revision for any reason demonstrated a cumulative survival of 94% at 7.4 years. In high-risk patients, DM bearings are successful at preventing and treating dislocation in THA. Primary cohort in this study all had multiple risk factors for instability but no dislocations or bearing specific complications were observed. Dislocations observed in Revision group were associated with major soft tissue deficiency. This study adds to the promising results already reported with DM THA articulations and should be considered for patients at risk of dislocation or instability. Runner Up – Best Paper Award

Introduction. The precise indications for tibial component metal backing and modularity remain controversial in routine primary total knee arthroplasty. This is particularly true in elderly patients where the perceived benefits of metal backing such as load redistribution and the reduction of polyethylene strain may be clinically less relevant. The cost implications for choosing a metal-backed design over an all-polyethylene design may exceed USD500 per primary knee arthroplasty case. Methods. A prospective randomised clinical trial was carried out at the QEII Health Sciences Centre, Halifax, Nova Scotia, to compare modular metal-backed versus an all-polyethylene tibial component. Outcome measures included clinical range of motion, radiographs, survivorship, Knee Society Clinical Rating System, WOMAC and SF-12. Results. 116 patients requesting primary knee arthroplasty were recruited and randomised between the Smith & Nephew Genesis I non-modular (57) and modular (59) tibial designs between September 1995 and August 1997. At 10 years clinical follow-up, 4 implant revisions or intention-to-revise decisions were recorded in the metal-tray/modular group of which 2 were for aseptic tibial component loosening. 2 implant revisions in the all-polyethylene non-modular group were recorded, neither of which were for tibial component loosening. At 5, 7 and 10 year review; the KSCRS, WOMAC and SF12 scores were similar in both groups. As most patients randomised were over seventy years of age, this impacted significantly on the numbers available for longer term review and data was analysed by comparing pre- and post-operative scores for individual patients. Conclusion. There was no difference in performance between the all-polyethylene tibial component and the metal-backed tibial component. The case for using the all-polyethylene tibia in elderly patients is justified on both clinical efficacy and cost-containment grounds

Introduction. Our department is responsible specifically for complex cases resulting from trauma. Our experience does not want to add what has been clearly demonstrated by multicenter studies on the efficacy of rivaroxaban but aims to demonstrate how the use of this molecule was effective also in mega-prosthesis and how it has proven to be flexible and safe in dealing with difficulties and surgical complications more common in such difficult cases. Materials and Methods. From January 2010 to date DVT prophylaxis in THR / TKR and revision was routinely performed with rivaroxaban. To date, in addition to first implant/revision in THR/TKR we treated over 30 cases of large segments replacements (large segments+mega-prosthesis) and we have not highlighted complications attributable to rivaroxaban. Discussion. We present in particular the medical and surgical management of three cases with a high risk of bleeding: a case of revision of total femur due to recurrent dislocation, one case of revision for early infection of a TKR and a case of traumatic acetabular revision for pelvicbreakthrough during rehabilitation. Conclusion. The major practical advantages found are: 1) the ability to choose when to start prophylaxis in relation to intraoperative bleeding Vs therapy that begins the previous day, 2) seeking the best prophylaxis for primary prosthetic and complex cases, the single-dose and pharmaco-kinetics/dynamic of rivaroxaban guarantee to be able to easily switch to a traditional prophylaxis in case of a need for further surgey Vs multi-dose of other oral drugs

The Vancouver classification separates periprosthetic femur fractures after THA into three regions (A - trochanteric, B - around or just below the stem, and C - well below the stem), with fractures around or just below the stem further separated into those with a well-fixed (B1) or loose stem and good (B2) or poor (B3) bone stock. Trochanteric fractures may be associated with osteolysis and require treatment that addresses osteolysis as well as ORIF of displaced fractures. Fractures around a well-fixed stem can be treated with ORIF using cerclage or cable plating, while those around a loose stem require implant revision usually to a longer cementless tapered or distally porous coated cementless stem. Fractures around a loose stem with poor bone stock in which salvage of the proximal femur is not possible require replacement of the proximal femur with an allograft prosthetic composite or proximal femoral replacement. Fractures well below the stem can be treated with conventional plating methods. Periprosthetic acetabular fractures are rare and usually occur in the early post-operative period or late as a result of osteolysis or trauma. These can generally be separated into those with a stable acetabular component which can be treated non-operatively, and those with an unstable component often with discontinuity or posterior column instability which require complex acetabular reconstruction utilizing plating or revision to a cup-cage

Introduction. Total hip replacement is one of the most successful orthopaedic surgeries, not least because of the introduction of modular systems giving surgeons the flexibility to intraoperatively adapt the geometry of the artificial joint to the patient's anatomy. However, taper junctions of modular implants are at risk of fretting-induced postoperative complications such as corrosion, which can lead to adverse tissue reactions. Interface micro-motions are suspected to be a causal factor for mechanical loading-induced corrosion, which can require implant revision. The aim of this study was to determine the micro-motions at the stem-head taper interface during daily activities and the influence of specific material combinations. Materials & Methods. The ball heads (ø 32mm, 12/14, size L, CoCr or Al2O3) were quasi-statically assembled to the stems (Ti or CoCr, Metha, Aesculap AG, Germany, v=0.5 kN/s, F=6 kN, n=3 each, 10° adduction/ 9° flexion according to ISO 7206-4) and then loaded sinusoidally using a material testing machine (Mini Bionix II, MTS, USA, Figure 1). The peak forces represented different daily activities [Bergmann, 2010]: walking (2.3 kN), stair climbing (4.3 kN) and stumbling (5.3 kN). 2,000 loading cycles (f=1 Hz) were applied for each load level. Six eddy-current sensors, placed between stem and head, were used to determine the displacement (interface micro-motion and elastic deformation) between head and stem (Figure 1). A finite element model (FEM) based on CAD data was used to determine the elastic deformation of the prostheses for the experimentally tested activities (Abaqus, Simulia, USA). Tie-junctions at all interfaces prevented relative movements of the adjacent surfaces. The resultant translations at the centre of the ball head were determined using a coordinate transformation and a subsequent subtraction of the elastic deformation. Results. FEM simulations exhibited a negligibly small elastic deformation for all material configurations indicating that the taper axis was located close to the direction of force application. The resultant micro-motions ranged between 3.3 and 33.4 µm and increased with rising peak forces for all material couplings (p<0.001, Figure 2). Ti–stems exhibited significantly larger micro-motions especially when combined with Al2O3-heads (Figure 2). The differences between the head materials on a similar stem material were not significant (p>0.857, Figure 2). Discussion. The observed differences between the two stem materials are unexpected. They might be due to the differences in stiffness between head and stem or to different taper surface morphologies. The same factors might also explain the different trends for the Ti-stems (larger for Al2O3-heads) compared to the CoCr-stems (larger for CoCr-heads). The magnitude of the observed micro-motions probably increases with contamination [Jauch, 2011] or insufficient assembly forces, facilitating fretting and crevice corrosion, which has been described for all of the combinations tested. Whether the measured magnitudes of micro-motion do already comprise a problem is presently unclear and requires further clarification