Displaced femoral neck fractures are commonly managed with hemiarthroplasty, yet there is an ongoing debate in literature regarding cemented versus cementless fixation. This review synthesizes evidence from recent randomized controlled trials, meta-analyses, registry-based studies, and cost-effectiveness analyses. Across studies, cemented fixation consistently reduces implant-related complications, particularly periprosthetic fractures, at the expense of slightly longer operative time. Mortality outcomes are largely comparable. Randomized trials generally show no significant differences, with some pooled evidence of improved one-year survival after cemented fixation. Registry data, however, indicate a modest increase in very early postoperative mortality among frail patients treated with a cemented stem, likely related to bone cement implantation syndrome. Functional outcomes and quality of life are marginally better with cemented stems in the early postoperative period, though differences diminish over time. Registry data uniformly show higher reoperation rates with cementless fixation. Cost-effectiveness analyses across healthcare systems identify cemented hemiarthroplasty as dominant, with lower costs and greater quality-adjusted life years. Current guidelines, including those from National Institute for Health and Care Excellence (NICE) and the American Academy of Orthopaedic Surgeons (AAOS), recommend cemented fixation. Nevertheless, substantial regional variation persists, with cementless stems still widely used in some countries. Overall, the evidence strongly supports cemented hemiarthroplasty as the preferred strategy for most older adults, while cementless fixation may be considered for highly comorbid patients at greatest risk from cement implantation. Future priorities include preserving surgical expertise in cementing techniques, enhancing global adherence to clinical guidelines, and advancing the identification of frail patient subgroups who may benefit from alternative strategies such as cementless implants or for whom nonoperative management may be more appropriate.

Introduction The proximal femur morphology changes with age, which may complicate the compatibility of contemporary cementless stem designs in very elderly patients. This study investigated the internal and external proximal femur morphology, correlated canal dimensions with external dimensions, and examined whether age-associated changes in the femoral canal and external morphology are related in subjects aged 80 years and older. Methods Three-dimensional models of human femora were reconstructed from computed tomographic (CT) scans of 90 very elderly subjects (mean 84 years, range 80-105 years). Morphological parameters describing the location of the femoral head center (FHC) (i.e. neck-shaft angle [NSA], mediolateral offset [ML-offset], and distance between lesser trochanter (LT) and FHC [LT-FHC]) and parameters describing the canal morphology (i.e. the cortices, canal dimensions, and canal flare index [CFI]) were measured. Regression and correlation analyses were performed in order to assess the relation between internal and external morphology. Results No significant associations regarding dimensions nor geometry between internal and external femur morphology could be detected. Canal dimensions were not able to predict the external dimensions more accurately than the deviation between the individual value and the mean value for the total cohort. Conclusions Based on these findings, proportional sizing of the cementless femoral component is not necessarily endorsed in very elderly patients, and age-associated changes of the femoral canal and external morphology do not appear to be related. However, further research is needed to evaluate the ability of contemporary non-modular cementless stems to anatomically reconstruct the proximal femur in very elderly patients specifically.

Introduction:Accurate reconstruction of the femoral head center (FHC) is essential for restoring hip biomechanics in total hip arthroplasty (THA). Previously described age-related morphological changes-such as canal widening and a mediocaudal FHC shift-may complicate anatomical reconstruction in all age-categories using a single non-modular cementless stem. This study assessed the capacity of such implant to achieve adequate FHC reconstruction across age groups and sexes. Methods:Virtual implantation of a non-modular cementless stem (SL-PLUS™) was performed in CT-based 3D reconstructions of 148 femora from middle-aged (<80 years) and very elderly (≥80 years) subjects. For each case, the optimal implant size, type (standard or lateral), and modular head (-4 mm, 0 mm or +4 mm) were selected. FHC deviation was measured in three dimensions; reconstructions were considered adequate if < 5 mm in all directions. Results:Overall, 92.4 % of reconstructions were considered adequate. No significant differences in reconstruction accuracy could be detected between age or sex groups. Very elderly males required significantly larger stem sizes than middle-aged males (mean size 6.4 vs. 5.1; p < 0.001). Lateralized stems were used more frequently in very elderly males (76.0 %) than in middle-aged males (44.4 %; p = 0.001). Reconstruction failure occurred in 11 cases, mostly due to a reduced mediolateral offset in femora with high native ML-offsets and/or low neck-shaft angles (8 out of 11 cases). Conclusions:A single non-modular cementless stem enables satisfactory FHC reconstruction in most patients, regardless of age or sex. However, certain anatomical configurations may exceed its reconstructive capacity. Careful preoperative planning is essential to identify cases that may need an alternative approach.

BackgroundOptimization of clinical pathways and logistics led to the introduction of outpatient joint arthroplasty of the hip and knee. Nevertheless, little is known about what these current protocols look like and how they differ from "standard" inpatient protocols. This study aimed to find preoperative, intraoperative, and postoperative differences between outpatient and inpatient pathways.MethodsA questionnaire (ranging between 23 and 37 items) was developed and administered by email to orthopedic surgeons who were a member of the Dutch Hip Society and Dutch Knee Society. Survey response rate was 38% (N = 117).ResultsNo significant differences were found in preoperative pathway characteristics. The administration regime for tranexamic acid significantly differed between outpatient and inpatient pathways (P < .001 and P = .002 for hip and knee arthroplasty, respectively), with outpatient pathways using a combined (eg, oral and intravenous) administration regime more frequently. The perioperative antibiotic prophylaxis regime also significantly differed between outpatient and inpatient pathways (P < .001 and P = .014, respectively), with outpatient pathways more frequently incorporating fewer antibiotic doses. Same-day postoperative mobilization significantly less often occurred if surgery took place later that day in inpatient hip arthroplasty pathways (24%; P = .034). Postoperative hemoglobin-check occurred significantly more often on indication in outpatient than in inpatient hip and knee arthroplasty pathways (∼75% vs ∼25%; P = .001).ConclusionsFew intraoperative and postoperative differences in outpatient and inpatient pathways were found and probably mainly relied on logistical grounds. Nonetheless, findings suggested that outpatient pathways tended to be more up-to-date and innovative than inpatient pathways.

Objectives We explored whether gender differences in burnout and work engagement characteristics among residents changed after the representation of female physicians has surpassed the 30% threshold of critical mass between 2005 and 2015, as well as if these gender differences are influenced by working in a surgical versus a non-surgical specialty.Methods This study used data of two questionnaire surveys on the well-being of Dutch residents, collected in 2005 (N = 2115) and 2015 (N = 1231). Burnout was measured with the validated Dutch translation of the Maslach Burnout Inventory, covering the characteristics emotional exhaustion, depersonalisation and personal accomplishment. Work engagement was measured with the Utrecht Work Engagement Scale, covering the characteristics vigour, dedication and absorption. Gender differences in residents' engagement and burnout characteristics in 2005 and 2015 were analysed using hierarchical regression analyses. Factorial analyses of variance were used to compare gender differences in residents' burnout and engagement characteristics in general surgery with those in internal medicine.Results In both years, female residents reported higher emotional exhaustion, lower depersonalisation, personal accomplishment, and vigour than males. These gender differences were similar in general surgery and internal medicine.Conclusions This study demonstrated unchanged gender differences in burnout and work engagement characteristics among residents after 10 years of demographic feminisation (increasing female representation), indicating higher risk for burnout and lower work engagement among females, both in surgical and non-surgical specialties. In view of the ever-increasing number of female residents, educators and hospitals need to create supporting work environments that safeguard residents' well-being.

Objective: To evaluate a shared decision-making (SDM) intervention in orthopaedic hip and knee osteoarthritis care. Methods: Using a pre- post intervention design study, we tested an intervention, that included a decision aid for patients (ptDA) and a SDM training course for residents in training and orthopaedic surgeons. The theory of planned behaviour was used for intervention development. Primary outcomes included patient reported decisional conflict, SDM, and satisfaction. Secondary outcomes were physicians' attitude and knowledge, and uptake of the ptDA. Results: 317 patients were included. The intervention improved physicians' knowledge about SDM but had no effect on the primary outcomes. 19 eligible patients used the ptDA (17%). SDM was higher for middle educated patients compared to lower educated (mean difference 9.91, p= 0.004), patients who saw surgeons instead of residents (mean difference 5.46, p= 0.044) and when surgery was chosen and desired by patients compared to situations where surgery was desired but not chosen (mean difference 15.39, p= 0.036). Conclusion: Our multifaceted intervention did not improve SDM and ptDA uptake was low. Practice Implications: In orthopaedic hip and knee osteoarthritic care other ways should be explored to successful implement SDM. Since residents received lower SDM scores, special focus should go to this group. (C) 2021 Elsevier B.V. All rights reserved.

Background:Outpatient joint arthroplasty (OJA) for the hip and knee is gaining popularity among orthopaedic surgeons worldwide. The purposes of this study were to (1) assess the proportion of Dutch orthopaedic surgeons who perform OJA; (2) identify surgeons' willingness to implement OJA in the future; (3) identify reasons and barriers to implement OJA; and (4) gather surgeon's perspective on the implementation of OJA. Methods:A 20-item survey was developed and administered by email to orthopaedic surgeons who are a member of the Dutch Hip Society and Dutch Knee Society. Survey response rate was 40% (N = 123). Results:Twenty-two respondents (18%) already implemented OJA, and 46% of respondents (who don't perform OJA) were interested to implement OJA in the future. Reasons to perform OJA included own positive experiences (82%), available evidence (77%) and patients' request (77%). Proponents' and opponents' view on safety and added value conflicted with each other. Other barriers included patient selection and organizational related (e.g., multidisciplinary support). Surgeons' view on evolution and relevance of OJA significantly differed by respondents who perform OJA versus respondents who don't perform OJA. Most respondents agreed with one another that the healthcare institution benefits most from OJA, and that optimization of the arthroplasty pathway could be reached through better patient education and -participation (e.g., eHealth, wearables). Conclusion:One in five respondents currently implement OJA pathways, and about half of the remaining respondents are interested to implement OJA in the future. OJA-opponents aren't convinced of the value and safety of OJA, despite accumulating evidence supporting OJA. Future research should inform patient-selection and -acceptance and organizational implementation.

Introduction: In cemented total hip arthroplasty (THA) various shapes and geometries of femoral implants are in use. Collarless, polished, and tapered (CPT) implants, and anatomically shaped (AS) implants are most commonly used. Due to their different design features, this might lead to different survival outcomes. In this register-based study, overall implant survival and short-term complications of CPT and AS cemented implants were evaluated. Methods: Data of the Dutch Arthroplasty Register (LROI) were used. Cemented femoral implants, which could be classified as CPT or AS were included in this study. Implants were excluded when no classification could be made or if implanted <100 times. Survival analyses were performed using Kaplan-Meier survival analysis and multivariable Cox-proportional hazard analysis. Results: 76,281 cemented THAs were included. At a mean of 5.1 years follow-up (SD 3.1, range 0–12 years), the overall survival of the AS implants was higher compared with the CPT implants, with a survival, of 99.2% and 99.0% respectively (log-rank; p < 0.001). Multivariable regression analysis revealed a higher rate for revision because of loosening of the AS implants (HR 2; CI, 1.4–3.1). AS implants had a lower rate for periprosthetic fractures compared with the CPT implants (HR 0.13; CI, 0.07–0.23). Conclusions: Both designs show excellent overall survival rates at short-term follow-up. There is a higher overall survival of AS implants when compared with CPT implants. Revision for implant loosening, however, was statistically significantly higher in AS implants when compared with the CPT implants.

Background In cementless hip arthroplasty, the femoral component should obtain firm fixation within the endosteal bone and achieve adequate reconstruction of hip joint biomechanics simultaneously. Previous anatomical studies described age-related changes of the proximal femoral canal, such as canal widening, which theoretically necessitates the use of larger stem sizes in elderly patients. This study examines a potential association between patients’ age at surgery and the implant size of a cementless femoral component. Material and methods A total of 13,423 primary hip arthroplasties with a single cementless stem registered in the Dutch Arthroplasty Register (LROI) were included. Patient characteristics (ie patients’ age, sex, height and weight at time of surgery) and femoral component size were derived. A one-way ANCOVA was used to compare the mean stem size between age groups, and multivariable linear regression analysis was used in order to investigate to which extent ageing impacted stem size. Results Each subsequent age- group (ten-year intervals) had a significantly larger mean stem size than the prior age- group. Multivariable linear regression analysis revealed that age is positively correlated with stem size and that this correlation is more prominent in females than in males (beta = .046, P < .001 and beta = .028, P < .001 respectively). Interpretation Implant size is positively correlated with age, in particular in females and independently from investigated anthropometric characteristics. The present study endorses that the femoral canal morphology is related to patients’ characteristics such as age and sex. The morphology will subsequently influence implant sizing and therefore may have biomechanical and clinical implications.

Prosthetic hip-associated cobalt toxicity (PHACT) is caused by elevated blood cobalt concentrations after hip arthroplasty. The aim of this study is to determine which symptoms are reported most frequently and in what type of bearing. We also try to determine the blood level of cobalt concentrations associated with toxicological symptoms. A systematic review was conducted on the 10th of July according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A methodological quality assessment (risk of bias (RoB)) was performed. Primary outcomes were the reported symptoms of cobalt toxicity and the level of cobalt concentrations in blood. These levels were associated with toxicological symptoms. A total of 7645 references were found of which 67 relevant reports describing 79 patients. The two most used bearings in which PHACT was described were metal-on-metal (MoM) bearings (38 cases) and revised (fractured) ceramic-on-ceramic (CoC) bearings where the former ceramic head was replaced by a metal head (32 cases). Of all reported symptoms, most were seen in the neurological system, of which 24% were in the sensory system and 19.3% were in central/peripheral system, followed by the cardiovascular (22.1%) system. The mean cobalt concentration for MoM-bearings was 123.7 ± 96.8 ppb and 1078.2 ± 1267.5 ppb for the revised fractured CoC-bearings. We recommend not to use a metal-based articulation in the revision of a fractured CoC bearing and suggest close follow-up with yearly blood cobalt concentration controls in patients with a MoM bearing or a revised fractured CoC bearing. Level of Evidence: Level V, systematic review.

Objectives Stimulating the active participation of residents in projects with societally relevant healthcare themes, such as value-based healthcare (VBHC), can be a strategy to enhance competency development. Canadian Medical Education Directions for Specialists (CanMEDS) competencies such as leader and scholar are important skills for all doctors. In this study, we hypothesise that when residents conduct a VBHC project, CanMEDS competencies are developed. There is the added value of gaining knowledge about VBHC. Design An explorative mixed-methods study assessing residents’ self-perceived learning effects of conducting VBHC projects according to three main components: (1) CanMEDS competency development, (2) recognition of VBHC dilemmas in clinical practice, and (3) potential facilitators for and barriers to implementing a VBHC project. We triangulated data resulting from qualitative analyses of: (a) text-based summaries of VBHC projects by residents and (b) semistructured interviews with residents who conducted these projects. Setting Academic and non-academic hospitals in the Netherlands. Participants Out of 63 text-based summaries from residents, 56 were selected; and out of 19 eligible residents, 11 were selected for semistructured interviews and were included in the final analysis. Results Regarding CanMEDS competency development, the competencies ‘leader’, ‘communicator’ and ‘collaborator’ scored the highest. Opportunities to recognise VBHC dilemmas in practice were mainly stimulated by analysing healthcare practices from different perspectives, and by learning how to define costs and relate them to outcomes. Finally, implementation of VBHC projects is facilitated by a thorough investigation of a VBHC dilemma combined with an in-depth stakeholder analysis. Conclusion In medical residency training programmes, competency development through active participation in projects with societally relevant healthcare themes—such as VBHC—was found to be a promising strategy. From a resident’s perspective, combining a thorough investigation of the VBHC dilemma with an in-depth stakeholder analysis is key to the successful implementation of a VBHC project.

Background: This study aims to present an overview and critical appraisal of all previous studies comparing costs and outcomes of the different modes of fixation in total hip arthroplasty (THA). A secondary aim is to provide conclusions regarding the most cost-effective mode of implant fixation per gender and age-specific population in THA, based on high quality studies.Methods: A systematic search was conducted to identify cost-effectiveness analyses (CEAs) comparing different modes of implant fixation in THA. Analysis of results was done with solely CEAs that had a high methodological quality.Results: A total of 12 relevant studies were identified and presented, of which 5 were considered to have the methodological rigor for inclusion in the analysis of results. These studies found that either cemented or hybrid fixation was the most cost-effective implant fixation mode for most age- and gender-specific subgroups.Conclusion: Currently available well performed CEAs generally support the use of cemented and hybrid fixation for all age-groups relevant for THA and both genders. However, these findings were mainly based on a single database and depended on assumptions made in the studies' methodology. Issues discussed in this paper have to be considered and future work is needed.

In orthopaedics, patient reported outcomes (PROMs) are designed to quantify changes in pain and to assess physical function, most often after joint arthroplasty. However, PROMs have some disadvantages, most important is their subjective nature. The aim was to investigate how patient-self-reported-outcomes of general health, disease-specific outcome and physical function, joint-awareness and self-perceived activity- levels are correlated with objectively-measured physical-activity (PA) parameters derived from wearable activity-monitors (AM) in subjects with a hip-arthroplasty. A prospective cohort study was conducted in a group of 32 patients, with a mean follow-up of 10 years after total hip arthroplasty. To assess different domains, the SF-36 (general health), HOOS-PS (pain/functional outcome), FJS-12 (joint awareness) and SQUASH (physical activity) were chosen. Activity-monitoring was performed using a 3-axis accelerometer, gyroscope and magnetometer. No significant correlations between PA-parameters and the FJS-12 and SQUASH were found. The HOOS- PS was significant correlated with BMI, the daily time walking and total-time active and the amount of daily steps. The physical functioning-subscale of the SF-36 was significant negative correlated with BMI and time sitting, but significant positive correlated with time walking, total-time active and the amount of daily steps. Considering the value of PA for maintaining general health, the value of using sensor-based AMs to assess efficacy of treatments in this health related dimension or use it as a tool for patient education, awareness and communication, seems very high.

Preliminary results of metal-on-metal (MoM) hip arthroplasty were satisfactory, but since 2004 data showed high failure rates. National joint replacement registries are multi-centre databases comprised of thousands of subjects and implants which allow for identifying variables predictive of implant failure. The aim of the current study was to estimate re-revision rates after revision of a primary MoM hip arthroplasty in the Dutch Arthroplasty Register (LROI) and to assess potential predictor variables of re-revision of these MoM hip arthroplasties. Eligible procedures were those with a revision for any reason except infection, after an initial primary surgery with a hip resurfacing (HRA) or large-head MoM (LH-MoM) total hip arthroplasty (THA). The probability of re-revision for both types of MoM hip arthroplasty over time was estimated using the cumulative incidence function taking mortality as a competing risk into account. A proportional sub-distribution hazards regression model was used to assess potential predictor variables of re-revision of these MoM hip arthroplasties. A total of 3476 records of revised implants were included, of which 873 (25.2%) were MoM implants. Over the course of follow-up, 101 (11.5%) MoM implants were re-revised. During follow-up 36 (4.3%) patients who received a MoM-implant at primary arthroplasty and a revision afterwards had died. The regression model showed that for primary MoM implants a MoM articulation after revision (HR 2.48; 95% CI 1.53–4.03, p < 0.001), femoral-only revisions (HR 3.20; 95% CI 2.06–4.99, p < 0.001) and periprosthetic fractures (HR 1.98; 95% CI 1.03–3.82, p = 0.042) as reason for the first revision were statistically significant risk factors for re-revision. Both types of large-head MoM hip arthroplasties have shown high revision and re-revision rates; risk factors were identified. The outcome of this study can be helpful in managing expectations of patients and orthopaedic surgeons.

With great interest, we have read the paper by Agarwal and colleagues, entitled: ‘Cost-effectiveness analyses of total hip arthroplasty for hip osteoarthritis: A PRISMA systematic review’, which was published in the International Journal of Clinical Practice's issue of February 2021.1 In this paper, the authors systematically reviewed cost-effectiveness analyses (CEAs) on total hip arthroplasty (THA) in its broadest sense. We share the same enthusiasm for CEAs in THA as the authors, which led to our recently published review on the cost-effectiveness of different implant fixation modes in THA in particular.2 Nevertheless, since our findings are not in accordance with the statements presented in the paper of Agarwal et al, we aimed to write this letter with a critical note. Regarding implant fixation mode in THA, the authors conclude: (a) that hybrid fixation is most cost-effective in elderly patients and (b) that there was a consensus across studies that in younger patients, cementless THA was the most cost-effective fixation mode. For the latter conclusion, the authors cited three papers in their discussion that were also identified within our search. It is our belief that the correct interpretation of available evidence is different and should be as follows: Pennington et al compared cemented, cementless and hybrid fixation in males and females aged 60, 70 and 80 years.3 Per fixation mode, they investigated the three most commonly used implant combinations in their database. In their paper, they reported the hybrid CPT/Trilogy (both Zimmer, Warsaw, Indiana) as the most cost-effective combination for males and females aged 60, 70 and 80 years. Based on their results, the hybrid fixation mode seems most cost-effective in all investigated ages and both genders. Marinelli et al compared cemented and cementless fixation.4 Because of issues in their methodology and reporting, this study was excluded from the in-depth analyses on cost-effectiveness in our review.2 However, in this paper, it was reported that early revision was higher in cementless fixation than cemented fixation (1.6% versus 1.4%), without any difference in QALYs. The costs were higher in cementless fixation compared with cemented fixation (€6,734 vs. €3,155). The authors concluded that cemented and cementless fixation seem equally cost-effective in THA. Di Tanna et al compared cementless and hybrid fixation, and expressed their base case incremental results in costs per revision-free life-year.5 Although Agarwal et al stated that studies which did not report quality-adjusted life years (QALYs) were not included, they still decided to include this study in their review.1 The results were presented for 30- to 90-year olds in 5-year intervals. In patients aged 40 years or younger, cementless fixation was dominant, between 45 and 80 years of age the incremental cost-effectiveness ratio (ICER) increased from €22 to €87 839 per revision-free life-year. In patients aged 85 years or older, hybrid fixation was dominant. Based on these results, cementless fixation seems cost-effective compared with hybrid fixation in the youngest population, while hybrid fixation seems cost-effective compared with cementless fixation in the eldest population. Since results were expressed in costs per revision-free life-year, no willingness to pay threshold could be applied for the age interval between 45 and 85 years. In addition to the studies above, Agarwal et al identified and presented two more studies that included the role of implant fixation mode on cost-effectiveness in THA in their review.6, 7 However, these studies were not cited when this topic was discussed in their paper 1: Fawsitt et al compared cemented, cementless, hybrid and reverse hybrid fixation in males and females in several age categories.6 The investigated implants were subdivided based on bearing surface and head size (small <36 mm versus large ≥36 mm). Therefore, a total of 24 implant combinations were studied. The cemented metal on polyethylene implant with small head combination was chosen as the reference implant combination, and a ranking list based on the incremental net monetary benefit (INMB) was constructed. Results were displayed per gender for patients aged <55 years up to patients aged >85 years with subsequent 10-year intervals. In their results, cemented fixation obtained the first and second place in the ‘most cost-effective’ implant combination ranking for all studied age categories and both genders. Pulikottil-Jacob et al studied cemented, cementless and hybrid fixation.7 Patients were stratified based on age (ie, 60, 70 and 80 years of age) and gender, and implants were subdivided based on bearing surface. In their results, the cemented fixation mode was dominant for all investigated age groups and both genders. Based on these studies, that were included in the review of Agarwal and colleagues, we do not believe it is fair to conclude that there is currently a consensus across studies that cementless THA is the most cost-effective implant fixation mode in younger patients, nor that hybrid fixation is necessarily the most cost-effective in elderly patients. In addition to these studies, our review presented another high-quality CEA on implant fixation in THA. Based on cost-effectiveness, Pennington et al advocated for cemented fixation in females aged 80 years and for hybrid fixation in all other investigated groups, while cementless fixation was dominated in all studied subgroups.8 Finally, a study was published after the latest search update of both reviews. Blythe et al studied the cost-effectiveness of cementless versus hybrid fixation in THA after a femoral neck fracture in several age groups.9 It was found that hybrid fixation was dominant for all studied age groups. In conclusion, we believe it is more convenient to conclude that the use of hybrid and cemented fixation in THA generally seems to be supported by currently available high-quality CEAs. However, many issues have to be considered in the interpretation of the presented works and future work is much needed, as was extensively elaborated on in our review article.2

Little is known about the influence of physical activity (PA) on metal ion concentrations in subjects with metal-on-metal hip arthroplasty. Implant wear is thought to be a function of use and thus of patient activity levels. It is hypothesized that daily habitual PA of patients with hip resurfacing arthroplasty (HRA) is associated with metal ion concentrations. Therefore a study was conducted in patients with a unilateral HRA at 10-years follow-up. Blood metal ion concentrations were determined. An acceleration-based activity monitor was used to measure PA in daily life. The cohort consisted of 12 males (75%) and 4 females (25%) with a median age at surgery of 55.5 ± 9.7 years [43.0-67.9] and a median follow-up of 9.9 ± 1.0 years [9.1-10.9]. The median cobalt and chromium ion concentrations were 25 ± 13 and 38 ± 28 nmol/L. A significant association between sit-stand transfers and high-intensity peaks with cobalt ion concentrations were found. Regarding PA and metal ion concentrations as a proxy of wear in HRA, specific activities like transfers or qualitative aspects of activity behavior like intensity, seem to matter more than the quantity of low-intensity activities like walking or cycling. This suggests that patients may safely engage in such activities to achieve important general health benefits and quality of life.

Metal-on-Metal hip arthroplasty was a frequently performed procedure, until concerns raised. Metal ion concentrations raise after the placement of a MoM prosthesis. This might lead to toxic concentrations of cobalt ions which might result in cardiotoxicity, thyroid toxicity and/or neuro-ocular toxicity. It is possible that raised cobalt and chromium concentrations have a role in the development of neurodegenerative diseases like Creutzfeldt-Jakob. We describe a patient with a MoM prosthesis who developed neurological symptoms were we thought of cobalt intoxication but turned out to be CreutzfeldtJakob disease.

Background and purpose - Hip resurfacing arthroplasty (HRA) was designed for the highly active patient because of the various theoretical advantages compared with stemmed total hip arthroplasty (THA), but has shown high failure rates. Physical activity (PA) after arthroplasty is frequently determined with the use of questionnaires, which are known for their subjective nature, recall bias, and ceiling effect. These disadvantages are not applicable to physical activity monitoring (AM) using sensors. We compared objectively measured PA at long-term follow-up in a matched cohort of HRA and stemmed THA subjects.Patients and methods - We compared 2 groups of 16 patients (12 males) in each group, one having received unilateral HRA (median age 56 years at surgery) and a matched group having received unilateral stemmed THA with a small diameter femoral head (28 mm) on conventional polyethylene (median age 60 years at surgery) with osteoarthritis as indication for surgery, 10 years after surgery. Groups were matched by sex, age at surgery, and BMI. The daily habitual PA was measured over 4 consecutive days in daily living using a 3-axis accelerometer, gyroscope, and magnetometer. Both quantitative parameters (time standing, sitting, walking, number of steps, and sit-stand transfers) and qualitative parameters (walking cadence) were determined.Results - The AM was worn for a median 13 (11-16) hours per day. The median daily step count was 5,546 (2,274-9,966) for the HRA group and 4,583 (1,567-11,749) for the stemmed THA-group with 39 (21-74) versus 37 (24-62) daily sit-stand transfers respectively. The other PA parameters were also similar in both groups.Interpretation - We found similar median PA levels and also identical ranges. While short-term effects may exist, ageing and related behavioral adaptations or other effects seem to render the theoretical activity benefits from HRA irrelevant at longer follow-up.

Background Outpatient joint arthroplasty (OJA) has gained increasing popularity and success in a well-defined population. Safety concerns, in terms of complications and readmissions, however still exist. Patients and Methods This retrospective study included 525 patients (90 primary THAs, 277 primary TKAs, and 158 primary UKAs), initially planned for OJA. All complications and readmissions were evaluated for timing and cause (surgical vs medical) within a 90-day followup. Complications and readmissions were compared by the length of stay (LOS): same-day discharge (SDD) vs ≥1 day. Differences were assessed by the log-rank test. Complications and readmission risk were assessed using multivariable logistic regression analysis. Results The complication rate was 9.9% at 30 days and 15% at 90 days. The readmission rate was 2.5% at 30 days and 4.2% at 90 days. The majority of surgical complications and readmissions were the result of wound discharge (43% and 56%, respectively). Overall, we did not observe different rates between SDD and LOS ≥1. Following THA, but not TKA or UKA, the 90-day complication rate was significantly lower in patients that underwent SDD compared with LOS ≥1. The risk of complications was positively associated with TKA (vs THA and UKA), ASA III (vs ASA I), and Charnley C (vs Charnley A). The risk of readmissions was negatively associated with a BMI ranging from 25-29.9 kg/m2 (vs BMI <25 kg/m2). Conclusion SDD following OJA did not result in more complications and hospital readmissions compared to a prolonged hospital stay. The majority of complications and readmissions were due to noninfected wound discharge.

BackgroundThe second generation metal-on-metal (MoM) prosthesis of the hip became a worldwide success in the 90s. However, after the placement of a MoM prosthesis the cobalt ion concentrations raise significantly. This may lead to systemic complaints and even cobalt toxicity.MethodsSixty-one patients (26F/35M) with both an unilateral and bilateral resurfacing or large-head MoM (LHMoM) hip prosthesis were included. At last follow-up (5.77 ± 1.57 yrs) cobalt concentrations in the blood were determined by ICP-MS. Based on the known cobalt toxicity symptoms we developed a non-validated questionnaire. Analysis was done on two groups; a low cobalt concentration group and a high cobalt concentration group. We used 170 nmol/L as the upper limit of well functioning prosthesis as defined by the Dutch Orthopaedic Society (NOV). Independent samples T test and Pearson correlation coefficient were done.ResultsIn 61 patients, 70 prosthesis were implanted: 44 resurfacings and 26 LHMoM. Mean cobalt and chromium ion concen...