Background and purpose. Previous publications have reported an increased but levelling out risk of revision for infection after total hip arthroplasty (THA) in Norway. We assessed the changes in risk of major (cup and/or stem, 1- or 2-stage) and minor revisions (debridement, exchange of modular parts, antibiotics and implant retention (DAIR)) for infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005-2022. Patients and methods. Primary THAs reported to the NAR from 2005 to 2022 were included. Time was stratified into time periods (2005-2009, 2010-2018, 2019-2022) based on a previous publication. Cox regression analyses, adjusted for sex, age and ASA-classification, with the first revision for infection were performed. Results. 140,338 primary THAs met the inclusion criteria. 1.3% (1,785) were revised for infection during the study period. 0.5% (638) had major revisions, whereas 0.8% (1,147) had DAIRs for infection. The risk of revision for infection was 1.2 (95%CI 1.1-1.4) for 2010-2018 and 1.0 (0.8-1.1) for 2019-2022 compared to 2005-2009. Compared to 2010-2018, the risk of revision for infection was 0.8 (0.7-0.9) for 2019-2022. The risk of DAIR for infection was 1.5 (1.3-1.9) for 2010-2018 and 1.2 (1.0-1.4) for 2019-2022 compared to 2005-2009. Compared to 2010-2018, the risk of DAIR for infection was 0.8 (0.7-0.9) for 2019-2022. The risk of major revision for infection was 0.8 (0.7-1.0) for 2010-2018 and 0.8 (0.6-1.0) for 2019-2022 compared to 2005-2009. Interpretation. The overall risk of revision for infection after THA, in Norway, has decreased in the period 2019-2022. The risk for DAIR initially increased in the period 2005-2009, levelled out 2010-2018 before starting to decrease in 2019-2022. The risk of major revision for infection was reduced in the period 2005-2009 before levelling out. This shows changes in revision strategies, but may also reflect a true decrease in periprosthetic joint infection

Aim. Previous publications have suggested that the incidence of revisions due to infection after THA is increasing. We performed updated time-trend analyses of risk and timing of revision due to infection after primary THAs in the Nordic countries during the period 2004–2018. Methods. 569,463 primary THAs reported to the Nordic Arthroplasty Register Association from 2004 through 2018 were studied. We estimated adjusted hazard ratios (aHR) with 95% confidence interval by Cox regression with the first revision due to infection after primary THA as endpoint. The risk of revision was investigated. In addition, we explored changes in the time span from primary THA to revision due to infection. Results. 5,653 (1.0%) were revised due to infection. The risk of revision due to infection increased through the study period. Compared to the period 2004–2008, the aHRs were 1.4 (95%CI 1.3–1.5) for 2009–2013, and 1.9 (1.7–2.0) for 2014–2018. We found an increased risk in all four Nordic countries. Compared to 2004–2008, the aHR due to infection 0–30 days after THA was 2.5 (2.1–2.9) for 2009–2013 and 3.4 (3.0–3.9) for 2013–2018. The aHR of revision due to infection 31–90 days after THA was 1.5 (1.3–1.9) for 2009–2013 and 2.5 (2.1–3.0) for 2013–2018, compared to 2004–2008. Beyond 91 days after THA, the risk of revision due to infection was stable over the whole study period. Interpretation. The risk of revision due to deep infection after THA nearly doubled throughout the period 2004–2018. This increase was mainly due to an increased risk of early revisions. The cause for these changes may be multifactorial (patient selection, diagnostics, revision strategy, completeness of reporting, etc.), are not possible to disclose in the present study, and warrants further research

Short cementless femoral stems are increasingly popular as they allow for less dissection for insertion. Use of such stems with the anterior approach (AA) may be associated with considerable per-operative fracture risk. This study's primary aim was to evaluate whether patient-specific femoral- and pelvic- morphology and surgical technique, influence per-operative fracture risk. In doing so, we aimed to describe important anatomical thresholds alerting surgeons. This is a single-center, multi-surgeon retrospective, case-control matched study. Of 1145 primary THAs with a short, cementless stem inserted via the AA, 39 periprosthetic fractures (3.4%) were identified. These were matched for factors known to increase fracture risk (age, gender, BMI, side, Dorr classification, stem offset and indication for surgery) with 78 THAs that did not sustain a fracture. Radiographic analysis was performed using validated software to measure femoral- (canal flare index [CFI], morphological cortical index [MCI], calcar-calcar ratio [CCR]) and pelvic- (Ilium-ischial ratio [IIR], ilium overhang, and ASIS to greater trochanter distance) morphologies and surgical technique (% canal fill). Multivariate and Receiver-Operator Curve (ROC) analysis was performed to identify predictors of fracture. Femoral factors that differed included CFI (3.7±0.6 vs 2.9±0.4, p3.17 and II ratio>3 (OR:29.2 95%CI: 9.5–89.9, p<0.001). Patient-specific anatomical parameters are important predictors of fracture-risk. When considering the use of short stems via the AA, careful radiographic analysis would help identify those at risk in order to consider alternative stem options

Background. Increasing evidence suggests a link between the bearing surface used in total hip arthroplasty (THA) and the occurrence of infection. It is postulated that polyethylene has immunomodulatory effects and may influence bacterial function and survival, thereby impacting the development of periprosthetic joint infection (PJI). This study aimed to investigate the association between polyethylene type and revision surgery for PJI in THA using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). We hypothesized that the use of XLPE would demonstrate a statistically significant reduction in revision rates due to PJI compared to N-XLPE. Methods. Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) spanning September 1, 1999, to December 31, 2021, were used to compare the infection revision rates between THA using N-XLPE and XLPE. We calculated the Cumulative Percentage Revision rate (CPR) and Hazard Ratio (HR) while controlling for factors like age, sex, body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, and head size. Results. From the total 361,083 primary THAs, 26,827 used N-XLPE and 334,256 used XLPE. Excluding data from the first 6 months post-surgery, 220 revisions occurred in the N-XLPE group and 1,055 in the XLPE group for PJI. The HR for infection revision was significantly higher in N-XLPE compared to XLPE, at 1.64 (95% CI, 1.41–1.90, p<0.001). Conclusions. This analysis provides evidence of an association between N-XLPE and revision for infection in THA. We suspect that polyethylene wear particles contribute to the susceptibility of THA to PJI, resulting in a significantly higher risk of revision for infection in N-XLPE hips compared to those with XLPE. Level of Evidence. Therapeutic Level III

Aim. Two types of national registers surveil infections after primary total hip arthroplasty (THA) in Norway: The National surveillance system for surgical site infections (NOIS) that surveil all primary THAs 30 days postoperatively for surgical site infections (SSI), and the Norwegian Arthroplasty Register (NAR) that follow all THAs until any surgical reoperation/revision or the death of the patient. Since these registers report on the same THAs we assessed correspondence between and time trends for the two registers in period 2013 to 2022. All reported THAs were included. Method. The THAs were matched on a group level according to sex, age and ASA-class. In addition to descriptive statistics, adjusted Cox regression analyses were performed with adjustment for sex, age group (<45, 45-54, 55-64, 65-74, 75-84, >85 years) and ASA-class (1, 2, 3, 4 and missing). Changes in annual incidence and adjusted hazard rate (aHR) was calculated. Endpoints in the NOIS were 30-Days SSI and 30-Days reoperation for SSI. Endpoints in the NAR were 30-Days and 1-Year reoperation for periprosthetic joint infection (PJI). Results. The NOIS had registered 87,923 THAs with 1,393 (1.58%) SSIs and 765 (0.87%) reoperations for SSI within 30 postoperatively. The NAR had registered 91,194 THAs with 725 (0.80%) reoperations for infection after 30 days, and 1,019 (1.21%) reoperations for infections after one year. The distribution of sex, age and ASA-class was near identical in the two registers. There was a mean annual reduction in risk of both SSI (aHR 0.92 (95% CI 0.90-0.93)) and reoperation for SSI (0.95(0.92-0.97)) and PJI (30-Days: 0.96 (0.94-0.99), 1-Year: 0.95-0.99)) over the period 2013-2022. Conclusions. The NOIS and the NAR have excellent completeness and the registrations in both registers may be considered representative for the Norwegian population. Not all SSI are reoperated. The incidence and risk of SSI (NOIS) and reoperation for PJI (NAR) is declining and may reflect a true reduction in incidence of PJI after primary THA

Total hip arthroplasty (THA) is an effective treatment for symptomatic hip osteoarthritis (OA). While computer-navigation technologies in total knee arthroplasty show survivorship advantages and are widely used, comparable applications within THA show far lower utilisation. Using national registry data, this study compared patient reported outcome measures (PROMs) in patients who underwent THA with and without computer navigation. Data from Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) PROMs program included all primary THA procedures performed for OA up to 31 December 2020. Procedures using the Intellijoint HIP® navigation system were identified and compared to procedures using other computer navigation systems or conventional instrumentation only. Changes in PROM scores between pre-operative and 6-month post-operative time points were analysed using multiple regression model, adjusting for pre-operative score, patient age, gender, ASA score, BMI, surgical approach, and hospital type. There were 65 primary THA procedures that used the Intellijoint HIP® system, 90 procedures used other types of computer navigation, and the remaining 5,284 primary THA procedures used conventional instrumentation. The estimated mean changes in the EuroQol visual analogue scale (EQ VAS) score and Oxford Hip score did not differ significantly when Intellijoint® was compared to conventional instruments (estimated differences of 2.4, 95% CI [-1.7, 6.5], p = 0.245, and −0.5, 95% CI [-2.5, 1.4], p = 0.592, respectively). The proportion of patients who were satisfied with their procedure was also similar when Intellijoint® was compared to conventional instruments (rate ratio 1.06, 95% CI [0.97, 1.16], p = 0.227). The preliminary data demonstrate no significant difference in PROMs when comparing the Intellijoint HIP® THA navigation system with both other navigation systems and conventional instrumentation for primary THAs performed for OA. Level of evidence: III (National registry analysis)

Total hip arthroplasty (THA) is an effective treatment for symptomatic hip osteoarthritis (OA). Computer-navigation technologies in total knee arthroplasty show evidence-supported survivorship advantages and are used widely. The aim of this study was to determine the revision outcome of hip commercially available navigation technologies. Data from the Australian Orthopaedic Association National Joint Replacement Registry from January 2016 to December 2020 included all primary THA procedures performed for osteoarthritis (OA). Procedures using the Intellijoint HIP® navigation were identified and compared to procedures inserted using ‘other’ computer navigation systems and to all non-navigated procedures. The cumulative percent revision (CPR) was compared between the three groups using Kaplan-Meier estimates of survivorship and hazard ratios (HR) from Cox proportional hazards models, adjusted for age and gender. A prosthesis specific analysis was also performed. There were 1911 procedures that used the Intellijoint® system, 4081 used ‘other’ computer navigation, and 160,661 were non-navigated. The all-cause 2-year CPR rate for the Intellijoint HIP® system was 1.8% (95% CI 1.2, 2.6), compared to 2.2% (95% CI 1.8, 2.8) for other navigated and 2.2% (95% CI 2.1, 2.3) for non-navigated cases. A prosthesis specific analysis identified the Paragon/Acetabular Shell THAs combined with the Intellijoint HIP® system as having a higher (3.4%) rate of revision than non-navigated THAs (HR = 2.00 (1.01, 4.00), p=0.048). When this outlier combination was excluded, the Intellijoint® system group demonstrated a two-year CPR of 1.3%. There was no statistical difference in the CPR between the three groups before or after excluding Paragon/Acetabular Shell system. The preliminary data presented demonstrate no statistical difference in all cause revision rates when comparing the Intellijoint HIP® THA navigation system with ‘other’ navigation systems and ‘non-navigated’ approaches for primary THAs performed for OA. The current sample size remains too small to permit meaningful subgroup statistical comparisons

Aim. To study whether revision for prosthetic joint infection (PJI) after early PJI in primary Total Hip Arthroplasty (THA) is associated with a high mortality, when compared with:. Patients, who did not undergo revision for any reason and Patients who underwent an aseptic revision. Method. This population-based cohort study was based on the Danish Hip Arthroplasty Register on primary THA performed in Denmark from 2005 to 2014. Data from the Danish Hip Arthroplasty Register were linked to microbiology databases, the National Register of Patients, and the Civil Registration System to obtain data on microbiology, comorbidity, and vital status on all patients. The mortality risk for the patients who underwent revision for PJI within 1 year from implantation of primary THA was compared with (1) the mortality risk for patients who did not undergo revision for any reason within 1 year of primary THA; and (2) the mortality risk for patients who underwent an aseptic revision. Results. A total of 68,504 primary THAs in 59,954 patients were identified, of those 445 primary THAs underwent revision for PJI, 1350 primary THAs underwent revision for other causes and the remaining 66,709 primary THAs did not undergo revision. Patients were followed from implantation of primary THA until death or 1 year of follow-up, or, in case of a revision, 1 year from the date of revision. Within 1 year of primary THA, 8% (95% CI, 6%–11%) of patients who underwent revision for PJI died. The adjusted relative mortality risk for patients with revision for PJI was 2.18 (95% CI, 1.54–3.08) compared with the patients who did not undergo revision for any cause (p < 0.001). The adjusted relative mortality risk for patients with revisions for PJI compared with patients with aseptic revision was 1.87 (9f5% CI, 1.11–3.15; p = 0.019). Patients with enterococci-infected THA had a 3.10 (95% CI, 1.66–5.81) higher mortality risk than patients infected with other bacteria (p < 0.001). Conclusions. Revision for PJI within 1 year after primary THA induces an increased mortality risk during the first year after the revision surgery. Especially enterococci-infected THA have a high motrtaly risk

Alternative bearing surfaces has been introduced to reduce wear debris-induced osteolysis after total hip arthroplasty (THA) and offered favorable results. Large population-based data for total joint surgery permit timely recognition of adverse results and prediction of events in the future. The purpose of this study was to present the epidemiology and national trends of bearing surface usage in primary total hip arthroplasty (THA) in Korea using nationwide database. A total of 30,881 THAs were analyzed using the Korean Health Insurance Review and Assessment Service database for 2007 through 2011. Bearing surfaces were sub-grouped according to device code for national health insurance claims and consisted of ceramic-on-ceramic (CoC), metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), and metal-on-metal (MoM). The prevalence of each type of bearing surface was calculated and stratified by age, gender, hospital type, primary payer, and procedure volume of each hospital. The number of primary THAs increased by 25.2% from 5,484 in 2007 to 6,866 in 2011. The average age of the entire study population was 58.1 years, and 53.5% were male [Table 1]. CoC was the most commonly used bearing surface (76.7%), followed by MoP (11.9%), CoP (7.3%), and MoM (4.1%). The distribution of bearing surfaces was identical to that in the general population regardless of age, gender, hospital type, and primary payer [Table 2]. The mean age of patients that received hard-on-hard bearing surfaces (CoC and MoM) was significantly younger than that of patients receiving hard-on-soft bearing surfaces (CoP and MoP) (56.9 years vs. 62.6 years). During the study period, 55.1% of THAs that used a hard-on-hard bearing surface were performed in males, while 53.0% of THAs that used a hard-on-soft bearing surface were performed in females. The order of prevalence of bearing surfaces was identical in low- and medium-volume hospitals (CoC was first, MoP was second, CoP was third, and MoM was fourth). The mean hospital charges did not differ according to the bearing surface used, with the exception of CoP, which was associated with a lower mean hospital charge. There were no changes in the distribution of bearing surfaces in each year between 2007 and 2011. Overall, the percentage of THAs that used CoC bearing surfaces increased substantially from 71.6% in 2007 to 81.4% in 2011, while the percentage that used CoP, MoP, and MoM decreased significantly [Fig. 1]. One of the reasons for the dominant usage of hard-on-hard bearing surfaces may be that the principal diagnosis of primary THAs and the patient age group distribution in Korea differ from those in other countries. The most common indication for primary THA is osteonecrosis of the femoral head in Korea. In contrast, the majority of primary THAs are performed for osteoarthritis in Western countries. The choice of bearing surface may be affected by many factors, including the nation's medical delivery system, payment type, disease pattern, and age distribution of patients that undergo THA. In future, the results of a large-scale nationwide study on primary THAs using CoC bearing surfaces in Korea will be reported. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Aim. The incidence of early periprosthetic joint infection (PJI) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is between 1 and 2 percent. In our department approximately 700 primary THAs and TKAs are performed annually. In 2015 and 2016 the incidence of early PJIs was nearly 3%. The aim of this study was to see if it was possible to reduce the incidence of infection by employing a bundle of measures by involving staff from all aspects of patient flow and addressing preventing measures in every step of the patients´ course throughout the hospital. Method. The Arthroplasty surgeon team reviewed the Proceedings of the International Consensus Meeting on Periprosthetic Joint Infection of 2013. Issues where literature had shown a significant effect on prevention of PJI was identified and written in an action plan. An interdisciplinary team with staff from all aspects of patient flow was established. In January 2017 the action plan was presented to the interdisciplinary team. The team discussed in what way the different issues could be solved, and issues that could be addressed without extra costs were implemented immediately. The issues addressed in the meeting were: preoperative risk factors, preoperative skin preparation, perioperative antibiotics, reducing particle amount and reducing traffic in the surgical theatre. Results. Early PJIs (symptoms within 30 days of index surgery) has been registered in our local quality register since 2011. Every infection is assured in order to apply to international criteria. There were 31 early PJIs among the 1100 primary THAs and TKAs performed before the intervention and 13 early PJIs among the 1100 after. The incidence the last two years before the intervention was 2.7% and the two years after intervention incidence was 1.2% (p=0.009). Conclusions. In this study we have shown that it is possible to reduce the incidence of early periprosthetic infections after primary THA and TKA in a university hospital. The patients referred to our department are of all categories, from healthy to great comorbidity. By focusing on optimizing the patient, preoperative antibiotics and traffic and behavior in the surgical theatre, we were able to reduce the infection incidence significantly. It is important to address the whole patient course, and introduce bundle of measures, in addition to involving staff from all aspects of the patient flow

Over the past several decades, cementless femoral fixation for primary total hip arthroplasties (THAs) has become more common in North America. It is estimated that nearly 90% of all primary THAs completed in the United States are cementless. In the Australian National Joint Replacement Registry, the use of cementless fixation has increased from 51.3% in 2003 to 63.3% in 2015. During the same time period, cemented fixation declined from 13.9% to 3.7%, but hybrid fixation was relatively stable at about 33%. This is likely related to the fact that multiple institutional and national registries have shown a higher rate of intra-operative periprosthetic femoral fractures with the use of cementless femoral components in certain patient populations. Those risk factors include patients greater than 65 years of age, female patients, and those with significant osteoporosis and Dorr C canals. However, it is important to note that not all cementless femoral components are similar. In fact, there is great variation in not only the geometry of cementless femoral components, but also in the type and extent of the biologic ingrowth surfaces. Each design has unique advantages and disadvantages. While some cementless femoral components are indicated for the general population, some are more specific and tailored to complex primary THAs (such as developmental dysplasia of the hip or post-traumatic arthritis with intra-operative concern for femoral version and thus hip stability) or revision procedures where distal fixation is needed (such as those with periprosthetic fractures or lack of proximal metaphyseal bony support). In 2000, Berry first described the evolution of cementless femoral components based upon distinct geometries that govern where fixation is obtained. This was modified in 2011 by Khanuja et al. to include six general types of cementless femoral components based upon shape. These include the following: Type 1: Single wedge; Type 2: Double edge with metaphyseal filling; Type 3: Tapered - A: Tapered round, B: Tapered spline/cone, C: Tapered rectangle; Type 4: Cylindrical fully coated; Type 5: Modular; Type 6: Anatomic. Type 1, 2, and 6 cementless femoral components obtain fixation in the metaphysis, whereas Type 3 stems obtain fixation in the metaphyseal-diaphyseal junction. Type 4 stems obtain fixation in the diaphysis. Type 5 stems can obtain fixation in either the metaphysis or the diaphysis. Within each type of stem, specific implant designs have had excellent long-term survivorship, while other specific implant designs have had higher than expected failure rates. Type 1 stems have the most published reports, and most contemporary reports indicate a stem survivorship greater than 95% at 15–20 years. Similar findings have been documented with specific implants from other types of stems when appropriate indications and surgical technique are utilised. Of note, one class of stems that has shown early failures due to adverse local tissue reactions (ALTR) is that of dual-modular necks. On the other hand, modular fluted tapered stems continue to produce excellent long-term data in complex primary THAs, as well as difficult revision THAs

Introduction. The global rapid growth of the aging population has some likelihood to create a serious crisis on health-care and economy at an unprecedented pace. To extend Healthy Life Expectancy (HALE) in a number of countries, it is desired more than ever to investigate characteristic and prognosis of numerous diseases. This enlightenment and recent studies on patient-reported outcome measures (PROMs) will drive the increasing interest in the quality of life among the world. The demand for primary THAs by 2030 would rise up to 174% in USA. It is expected that the number of the elderly will surge significantly in the future, thus more septuagenarian and octogenarian are undergoing THA. Moreover, HALE of Japanese female near the age of 75 years, followed to Singapore, is still increasing. Therefore, concerns exist about the PROMs of performing THA in this age-group worldwide. Nevertheless almost the well-established procedure, little agreement has been reached to the elderly. We aimed to clarify the mid-term PROMs after THA over 75-year old. Methods. Between 2005 and 2013, we performed 720 consecutive primary cemented THAs through a direct lateral approach. Of these, 503 female patients (655 hips) underwent THA for treatment of osteoarthritis, with a minimum follow-up of 5 years, were retrospectively enrolled into the study. We excluded 191 patients (252 hips) aged less than 65-year at the time of surgery and 58 patients (60) because of post-traumatic arthritis or previous surgery (37), or lack of data (23). Thus, 343 hips remained eligible for our study, contributed by 254 patients. We investigated Quality-adjusted life year (QALY), EuroQol 5-Dimension 5-Level scale (EQ-5D) and the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ, which was a disease-specific and self-administered questionnaire, reflecting the specificity of the Japanese cultural lifestyle) in patients aged 75 years or older (154 hips, Group-E) compared with those aged 65 to 74 years (189 hips, Group-C) retrospectively. We evaluated the association between patients aged 75 years or older and the following potential risk factors, using logistic regression analysis: age, number of vertebral fractures (VFs), American Society of Anesthesiologists physical status (ASA-PS) and Charlson Comorbidity Index (CCI). A p value of < 0.05 was considered significant for the Mann-Whitney U test. Results. At a mean follow-up duration of 7.2 years, QALY, EQ-5D and JHEQ for the domain of patient satisfaction were significantly greater for Group-E than Group-C; however, there were no significant differences in JHEQ for pain, movement and mental-health between groups. On multivariate analysis, the age (odds ratio [OR] 2.48, p < .01 for EQ-5D; OR .32, p < .01 for JHEQ satisfaction), VFs (OR 1.63, p < .01 for satisfaction) and ASA-PS (OR .64, p = .31 for EQ-5D) were independent predictive risk factors for patients aged 75-year or older. Conclusions. Based on mid-term follow-up of PROMs study, we suggest that cemented THA can lead to the extension of HALE towards the super aged society and our results can be applied to a systematic analysis for the Global Burden of Disease Study related frailty

Aim. The aim of this study was to validate the information on operating room ventilation reported to the Norwegian Arthroplasty Register (NAR) and to assess the influence of this ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA). Method. Current and previous ventilation systems were evaluated together with the hospitals head engineer in 40 orthopaedic hospitals. The ventilation system of each operating room was assessed and confirmed as either conventional ventilation, vertical laminar airflow (LAF) or horizontal LAF. We then identified cases of first revision due to deep infection after primary THA and the type of ventilation system reported to the NAR in the period 1987–2014. The association between revision due to infection and operating room ventilation was estimated by relative risks (RR) in a Cox regression model. Results. 103370 primary THAs and 971 (0.9%) first revisions due to deep infection were reported. 51% of the primary THAs were performed in a room with vertical LAF, 44% in a room with conventional ventilation and 5% in a room with horizontal LAF. There was a mean misreporting rate of approximately 12%. There was similar risk of revision due to infection after THA performed in operating rooms with vertical laminar air flow compared to conventional ventilation (RR=0.95, 95 % CI: 0.8–1.1) and an increased risk of revision due to infection after THA performed in horizontal LAF conditions compared to conventionally ventilated conditions (RR=1.3, 95 % CI: 1.0–1.7). Conclusions. Surgeons are not fully aware of what kind of ventilation there is in the operating room. This study may indicate that vertical LAF is not superior to conventional ventilation concerning reduction of THA infection, and therefore does not justify any increased installation costs. Also, horizontal LAF systems appear to be inferior to other ventilation systems

INTRODUCTION. Utilization of a patient management support system in our clinical pathway has been successfully demonstrated to both reduce the length of hospital stay after primary THA, as well as reducing the number of hospital readmissions. While successful in a general patient population, the ability of a patient management support system to reduce readmissions in subsets of high risk THA patients has not been evaluated. METHODS. We identified all primary THAs performed at a single institution between 2013 and 2015. Patient sex, age at the time of surgery, race, ASA grade, and 120-day readmissions were retrieved from the patient medical record. Similar to previous studies, the patient's home address was used as a proxy for socioeconomic status, with the estimated median income of a given patient being estimated as the median household income for patients of similar ethnicity living within their zip code as reported in the 2014 U.S. Census. A binary regression was used to determine if a model of patient factors (age, sex, race, socioeconomic status, and/or ASA grade) could accurately predict 120-day readmission after primary THA. Age and socioeconomic status were treated as a continuous variable and all other factors were categorical in nature, and the individual effects of each categorical factor on readmissions were also assessed. RESULTS. A sample of 889 primary THAs was identified using the above criteria, of which 754 (84.8%) were Caucasian and 124 (13.9%) were African Americans. Eleven patients (1.2%) either self-reported a different race or race was unknown. Due to the small number of patients in the other/unknown group, this subset was not included in our analysis. With the remaining sample of 878 THAs (475 females, 403 males; age 62.1 ± 13.0 years), a model containing age, sex, race, socioeconomic status, and ASA grade was unable to accurately predict the need for hospital readmission (R2 = 0.02). When assessed individually, the rates of hospital readmission did not differ by sex or race; however, those with ASA grades I or II had significantly lower readmission rates than patients with ASA grades III or IV (Table 1). DISCUSSION AND CONCLUSION. Despite a comprehensive program, the risk of readmission for patients with greater comorbidity burdens was double that of patients with low ASA grades

While total hip arthroplasty (THA) is the most predictable and successful operation for relieving pain and restoring function in the arthritic hip, instability and dislocation have been identified as the most common cause (22.5%) of revision THA in the United States. Thus, minimizing the complications of impingement and dislocation are major goals for surgeons and implant designers. A dual-mobility (DM) socket design, where there is an additional bearing with a mobile polyethylene component between the prosthetic head and the acetabular shell, was introduced in the United States in 2010. Developed by Bousquet in 1974, the DM design has been shown to be a durable solution to hip instability after THA. The smaller inside diameter head offers the potential advantage of lower wear and the larger outside diameter head offers the potential advantage of improved stability. A review of eight studies using a DM design noted only two dislocations in 1,386 (0.1%) primary THAs. Initially, indications were advocated for patients with increased instability risk as in revision THA or THA after femoral neck fracture. However, with larger diameter metal-on-metal articulations falling out of favor, DM components are increasingly being used in younger patients. Between 2011 and 2014, the author has used DM sockets in over 400 primary THAs (age, 22–92 years). Only one dislocation was noted in this group (femoral neck fracture). One loose cup was revised. Dislocation of the smaller femoral head from the larger polyethylene head remains a theoretical risk with DM designs

The aim of this study was to validate the information on operating room ventilation reported to the Norwegian Arthroplasty Register (NAR). We then wanted to assess the influence of operating room ventilation on the rate of revision due to infection after primary THA performed in operating rooms with conventional ventilation, “greenhouse”–ventilation and Laminar Airflow ventilation (LAF). We identified cases of THA revisions due to deep infection and the type of ventilation system reported to the NAR from the primary THA. We included 5 orthopaedic units reporting 17947 primary THAs and 136 (0.8%) revisions due to infection during the 28 year inclusion period from 1987 to 2014. The hospitals were visited and the current and previous ventilation systems were evaluated together with the hospitals head engineer, and the factual ventilation on the specific operating rooms was thereby assessed. The association between revision due to infection and operating room ventilation was estimated by calculating relative risks (RR) in a Cox regression model. 73% of the primary THAs were performed in a room with LAF, in contrast to the reported 80 % of LAF. There was similar risk of revision due to infection after THA performed in operating rooms with laminar air flow compared to conventional ventilation (RR=0.7, 95 % CI: 0.2–2.3) and after THA performed in operating rooms with “greenhouse”-ventilation compared to conventional ventilation (RR=1.2, 0.1–11). Surgeons are not fully aware of what kind of ventilation there is in the operating room. This study may indicate that, concerning reduction in incidence of THA infection, LAF does not justify the substantial installation cost. The numbers in the present study are too small to conclude strongly. Therefore, the study will be expanded to include all hospitals reporting to the NAR

Background. Large head metal on metal total hip arthroplasty MOM THA have been consistently shown substantial improvement in wear performance compared with metal on polyethylene articulations. Large diameter femoral heads theoretically can reduce dislocation risk by increasing range of motion before impingement, increasing prosthetic jump distance. However, early failure associated with adverse local tissue reactions (ALTRs) to metal debris is an emerging problem after MOM THA. The purpose of this study was to evaluate mid-term results of MOM THA. Materials and Methods. Twenty-five patients, 28 hips were included in this study. The average age of the patients at the time of surgery was 66.9 years. Three patients were men and 22 were women. MOM THAs were performed using 28 PINNACLE Cup system (DepPuy) (C-STEM: 23, S-ROM: 5) with posterior approach and head size of 36mm. Twenty-five primary THAs due to osteoarthritis in 22 cases and rheumatoid arthritis (RA) in one, and two revisions due to recurrent dislocation THA patients, were performed. The average follow up was 56.7 months. Evaluation items are JOA score, cup anteversion /lateral opening angle, and complications. Indication of the system were applied for patients with high risk of dislocation such as recurrent dislocation in primary and/or THAs, posterior pelvic tilt, elderly, RA and mental disorders. Results. The average JOA score improved from 48.3 (range: 26–77) preoperatively to 88.3 (range: 55–100) postoperatively. The average cup anteversion was 21.7 degrees (range: 2–38) and average lateral opening was 45.5 degrees (range: 37–60). Three patients (12%) developed dislocation. Two patients (8%) required reoperations from the deep infection. One female patient (4%) remained hip pain and was suspected pseudotumor / ALTR, which was confirmed by computed tomography and magnetic resonance imaging. Conclusion. Large femoral head MOM THA was useful for patients with recurrent dislocation in revision THA. However, three patients developed dislocation in primary THAs (12% of primary cases), which suggested that the more accurate placement of the acetabular cup is important even in the large diameter cup. Although only one case (4%) revealed ALTR, however, continuous careful follow-up would be necessary in the MOM system

Introduction. Ultra-high molecular weight polyethylene (UHMWPE) tape, which comprised threads of UHMWPE fibers with the thickness less than 0.5 mm, was developed as a flexible fixation device. We describe new techniques using UHMWPE tape for the reattachment of the osteotomised fragment and the repair of intraoperative calcar fractures in total hip arthroplasty (THA). Patients & Methods. We reviewed the medical records and radiographs of the studied subjects after approval of this study by the institutional review board committee. Experiment 1: Between October 2011 and May 2012, 60 consecutive primary THAs were performed with the mini-trochanteric approach, which involved reattaching the osteotomised fragment using UHMWPE tape (Nesplon; Alfresa Pharma, Osaka, Japan). [Fig.1] By splitting the anterior one-fourth of the gluteus medius, the minitrochanteric osteotomy, a half-ellipsoid body about 15 mm long, 10 mm wide, and 5 mm deep, is performed using a curved chisel. After implanting of the prosthesis, the osteotomised fragment is reattached by using two 3-mm wide Nesplon tapes. Using 2.4 mm Kirshner wire, two sets of drill holes are created below the trochanteric bed of the femur. Nesplon tapes are passed through each drill hole and penetrated over the trochanteric fragment. Nesplon tape is tied using a double-loop sliding knot in conjunction with a special tightening gun tensioner up to 20 kgf. [Fig.2] The radiographic results were retrospectively analyzed to determine the incidence of nonunion and complications related to trochanteric site. Hip functional results were rated according to the Japanese Orthopedic Association (JOA) hip score. Experiment 2: Between July 2011 and May 2012, 5-mm wide Nesplon tapes were used for restoration of intraoperative femoral fractures in 4 primary THAs. For the repair of intraoperative proximal femoral fractures, 5-mm wide Nesplon tape is tightened with cerclage wiring technique using the gun tensioner up to 30 kgf. [Fig.3] The postoperative radiographic changes were analyzed. Results. Experiment 1: Nonunions occurred in no (0%) patient. Bone union with minimally displaced was present in three (5.0%) patients. The mean JOA scores improved 47.1 to 84.6 at 1 year postoperatively. Experiment 2: There were no migrations of the femoral prosthesis in the postoperative period. Discussion. These techniques using UHMWPE tapes are simple and more advantageous to prevent the complications resulting from metal wires. UHMWPE tape, which has flat configuration with high flexibility, can provide a greater contact area avoiding the risk of bone cutout. Using a special tightening gun can easy reattachment with precise tension even in the setting of poor bone quality

Aim. The aim of this study was to assess the influence of the true operating room (OR) ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA) reported to the Norwegian Arthroplasty Register (NAR). Method. 40 orthopedic units were included during the period 2005 – 2015. The Unidirectional airflow (UDAF) systems were subdivided into small-area, low-volume, vertical UDAF (lvUDAF) (volume flow rate (VFR) (m. 3. /hour) <=10,000 and diffuser array size (DAS) (m. 2. ) <=10); large-area, high-volume, vertical UDAF (hvUDAF) (VFR >=10,000 and DAS >=10) and Horizontal UDAF (H-UDAF). The systems were compared to conventional, turbulent ventilation (CV) systems. The association between revision due to infection and OR ventilation was assessed using Cox regression models, with adjustments for sex, age, indication for surgery, ASA-classification, method of fixation, modularity of the components, duration of surgery, in addition to year of primary THA. All included THAs received systemic, antibiotic prophylaxis. Results. 51,292 primary THAs were eligible for assessment. 575 (1.1%) of these THAs had been revised due to infection. Compared to CV, there was similar risk of revision due to infection after THA performed in ORs with lvUDAF (RR=0.9, 95 % CI: 0.7–1.1) and with H-UDAF (RR=1.3, 95 % CI: 0.9–1.8). The risk of revision due to infection after THA performed in ORs with large-area hvUDAF-systems was lower (RR=0.8, 95% CI: 0.6–0.9, p=0.01) compared to CV. Conclusions. This study indicates that large-area, high-volume, vertical UDAF systems may be superior to conventional ventilation systems as a prophylactic measure against THA infection. This emphasizes the importance of assessing the big diversity of different ventilation systems when studying effect measures

There are numerous factors that influence total hip arthroplasty (THA) stability including surgical approach, soft-tissue tensioning, impingement, abductor status, and component positioning. A long-held tenet regarding acetabular component positioning is that cup inclination and anteversion of 40 ± 10 degrees and 15 ± 10 degrees, respectively, represents a “safe zone” as to minimise dislocation after primary THA. However, several studies have recently challenged that notion for individual patients. A study completed by Abdel et al. identified a cohort of 9784 primary THAs performed at a single institution with 206 THAs (2%) that subsequently dislocated. The authors determined that 58% of the dislocated THAs had their acetabular component within the safe zone for both acetabular inclination and anteversion. When looked at separately, 84% had their inclination within the safe zone (mean value of 44 ± 8 degrees), and 69% had their anteversion within the safe zone (mean value of 15 ± 9 degrees). As such, surgeons should take into account that cup positioning alone does not determine the risk of instability following THA, as there are a multitude of other factors that can contribute to dislocation. Hip stability is multifactorial and likely patient-specific, and must take into account bony and muscular anatomy, static and dynamic soft tissue balance and intraoperative tensioning, and the functional demand and rehabilitative efforts of the patient