Periprosthetic Joint Infection After Total Knee Arthroplasty With or Without Antibiotic Bone Cement.

Importance: Despite increased use of antibiotic-loaded bone cement (ALBC) in joint arthroplasty over recent decades, current evidence for prophylactic use of ALBC to reduce risk of periprosthetic joint infection (PJI) is insufficient. Objective: To compare the rate of revision attributed to PJI following primary total knee arthroplasty (TKA) using ALBC vs plain bone cement. Design, Setting, and Participants: This international cohort study used data from 14 national or regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, New Zealand, Norway, Romania, Sweden, Switzerland, the Netherlands, the UK, and the US. The study included primary TKAs for osteoarthritis registered from January 1, 2010, to December 31, 2020, and followed-up until December 31, 2021. Data analysis was performed from April to September 2023. Exposure: Primary TKA with ALBC vs plain bone cement. Main Outcomes and Measures: The primary outcome was risk of 1-year revision for PJI. Using a distributed data network analysis method, data were harmonized, and a cumulative revision rate was calculated (1 - Kaplan-Meier), and Cox regression analyses were performed within the 10 registries using both cement types. A meta-analysis was then performed to combine all aggregated data and evaluate the risk of 1-year revision for PJI and all causes. Results: Among 2 168 924 TKAs included, 93% were performed with ALBC. Most TKAs were performed in female patients (59.5%) and patients aged 65 to 74 years (39.9%), fully cemented (92.2%), and in the 2015 to 2020 period (62.5%). All participating registries reported a cumulative 1-year revision rate for PJI of less than 1% following primary TKA with ALBC (range, 0.21%-0.80%) and with plain bone cement (range, 0.23%-0.70%). The meta-analyses based on adjusted Cox regression for 1 917 190 TKAs showed no statistically significant difference at 1 year in risk of revision for PJI (hazard rate ratio, 1.16; 95% CI, 0.89-1.52) or for all causes (hazard rate ratio, 1.12; 95% CI, 0.89-1.40) among TKAs performed with ALBC vs plain bone cement. Conclusions and Relevance: In this study, the risk of revision for PJI was similar between ALBC and plain bone cement following primary TKA. Any additional costs of ALBC and its relative value in reducing revision risk should be considered in the context of the overall health care delivery system.

Autoimmune comorbidity in type 1 diabetes and its association with metabolic control and mortality risk in young people: a population-based study.

AIMS/HYPOTHESIS: This register-based study aimed to describe autoimmune comorbidity in children and young adults from type 1 diabetes onset, and to investigate whether such comorbidity was associated with a difference in HbA1c or mortality risk compared with children/young adults with type 1 diabetes without autoimmune comorbidity. METHODS: A total of 15,188 individuals from the Swedish National Diabetes Register, registered with type 1 diabetes before 18 years of age between 2000 and 2019, were included. Five randomly selected control individuals from the Swedish population (Statistics Sweden) were matched to each individual with type 1 diabetes (n=74,210 [346 individuals with type 1 diabetes were not found in the Statistics Sweden register at the date of type 1 diabetes diagnosis, so could not be matched to control individuals]). The National Patient Register was used to attain ICD-10 codes on autoimmune diseases and the Cause of Death Register was used to identify deceased individuals. RESULTS: In the total type 1 diabetes cohort, mean±SD age at onset of type 1 diabetes was 9.5±4.4 years and mean disease duration at end of follow-up was 8.8±5.7 years. Of the individuals with type 1 diabetes, 19.2% were diagnosed with at least one autoimmune disease vs 4.0% of the control group. The HRs for comorbidities within 19 years from onset of type 1 diabetes were 11.6 (95% CI 10.6, 12.6) for coeliac disease, 10.6 (95% CI 9.6, 11.8) for thyroid disease, 1.3 (95% CI 1.1, 1.6) for psoriasis, 4.1 (95% CI 3.2, 5.3) for vitiligo, 1.7 (95% CI 1.4, 2.2) for rheumatic joint disease, 1.0 (95% CI 0.8, 1.3) for inflammatory bowel disease, 1.0 (95% CI 0.7, 1.2) for systemic connective tissue disorder, 1.4 (95% CI 1.1, 1.9) for uveitis, 18.3 (95% CI 8.4, 40.0) for Addison's disease, 1.8 (95% CI 0.9, 3.6) for multiple sclerosis, 3.7 (95% CI 1.6, 8.7) for inflammatory liver disease and 19.6 (95% CI 4.2, 92.3) for atrophic gastritis. Autoimmune disease in addition to type 1 diabetes had no statistically significant effect on HbA1c or mortality risk. CONCLUSIONS/INTERPRETATION: To our knowledge, this is the first comprehensive study where young individuals with type 1 diabetes were followed regarding development of a wide spectrum of autoimmune diseases, from onset of type 1 diabetes. In this nationwide and population-based study, there was already a high prevalence of autoimmune diseases in childhood, especially coeliac and thyroid disease. The presence of autoimmune comorbidity did not have a statistically significant effect on metabolic control or mortality risk.

The use of antibiotic-loaded bone cement and systemic antibiotic prophylactic use in 2,971,357 primary total knee arthroplasties from 2010 to 2020: an international register-based observational study among countries in Africa, Europe, North America, and Oceania.

BACKGROUND AND PURPOSE: Antibiotic-loaded bone cement (ALBC) and systemic antibiotic prophylaxis (SAP) have been used to reduce periprosthetic joint infection (PJI) rates. We investigated the use of ALBC and SAP in primary total knee arthroplasty (TKA). PATIENTS AND METHODS: This observational study is based on 2,971,357 primary TKAs reported in 2010-2020 to national/regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, the Netherlands, New Zealand, Norway, Romania, South Africa, Sweden, Switzerland, the UK, and the USA. Aggregate-level data on trends and types of bone cement, antibiotic agents, and doses and duration of SAP used was extracted from participating registries. RESULTS: ALBC was used in 77% of the TKAs with variation ranging from 100% in Norway to 31% in the USA. Palacos R+G was the most common (62%) ALBC type used. The primary antibiotic used in ALBC was gentamicin (94%). Use of ALBC in combination with SAP was common practice (77%). Cefazolin was the most common (32%) SAP agent. The doses and duration of SAP used varied from one single preoperative dosage as standard practice in Bolzano, Italy (98%) to 1-day 4 doses in Norway (83% of the 40,709 TKAs reported to the Norwegian arthroplasty register). CONCLUSION: The proportion of ALBC usage in primary TKA varies internationally, with gentamicin being the most common antibiotic. ALBC in combination with SAP was common practice, with cefazolin the most common SAP agent. The type of ALBC and type, dose, and duration of SAP varied among participating countries.

Prediction of Early Periprosthetic Joint Infection After Total Hip Arthroplasty.

Purpose: To develop a parsimonious risk prediction model for periprosthetic joint infection (PJI) within 90 days after total hip arthroplasty (THA). Patients and Methods: We used logistic LASSO regression with bootstrap ranking to develop a risk prediction model for PJI within 90 days based on a Swedish cohort of 88,830 patients with elective THA 2008-2015. The model was externally validated on a Danish cohort with 18,854 patients. Results: Incidence of PJI was 2.45% in Sweden and 2.17% in Denmark. A model with the underlying diagnosis for THA, body mass index (BMI), American Society for Anesthesiologists (ASA) class, sex, age, and the presence of five defined comorbidities had an area under the curve (AUC) of 0.68 (95% CI: 0.66 to 0.69) in Sweden and 0.66 (95% CI: 0.64 to 0.69) in Denmark. This was superior to traditional models based on ASA class, Charlson, Elixhauser, or the Rx Risk V comorbidity indices. Internal calibration was good for predicted probabilities up to 10%. Conclusion: A new PJI prediction model based on easily accessible data available before THA was developed and externally validated. The model had superior discriminatory ability compared to ASA class alone or more complex comorbidity indices and had good calibration. We provide a web-based calculator (https://erikbulow.shinyapps.io/thamortpred/) to facilitate shared decision making by patients and surgeons.

Worse patient-reported outcomes and higher risk of reoperation and adverse events after total hip replacement in patients with opioid use in the year before surgery: a Swedish register-based study on 80,483 patients.

Background and purpose - Recent studies indicate that preoperative use of opioids could be associated with higher rates of complications and worse patient-reported outcomes (PROs) after orthopedic surgery. We investigated the prevalence of preoperative opioid use and analyzed its influence on risk of revision, adverse events (AE), and PROs in patients with total hip replacement (THR). Patients and methods - This observational study included 80,483 patients operated on in 2008-2016 with THRs due to osteoarthritis. Data was obtained from the Swedish Hip Arthroplasty Register, Statistics Sweden's sociodemographic registers, the Swedish National Patient Register, and the Prescribed Drug Register. We focused on patients with ≥ 4 opioid prescriptions filled 1 year prior to THR. To control for confounding, we used propensity scores to weight subjects in our analyses. Logistic and linear regression was used for outcome variables with adjustments for sociodemographic variables and comorbidities. Results - Patients with ≥ 4 opioid prescriptions in the year before THR (n = 14,720 [18%]) had a higher risk of revision within 2 years (1.8% vs. 1.1% OR 1.4, 95% CI 1.3-1.6) and AE within 90 days (9.4% vs. 6.4% OR 1.2, 95% CI 1.2-1.3) compared with patients without opioid treatment in the preoperative period. Patients with ≥ 4 opioid prescriptions rated 5 points worse on a 0-100 scale of Pain Visual Analogue Scale (VAS) and 9 points worse on a general health (EQ) VAS 1 year postoperatively. Interpretation - Having ≥ 4 opioid prescriptions filled in the year before surgery is associated with a higher risk of revision, adverse events, and worse PROs after THR. Consequently, preoperative opioid treatment should be addressed in the clinical assessment of patients eligible for THR.

Prediction of 90-day mortality after total hip arthroplasty.

AIMS: To develop and externally validate a parsimonious statistical prediction model of 90-day mortality after elective total hip arthroplasty (THA), and to provide a web calculator for clinical usage. METHODS: We included 53,099 patients with cemented THA due to osteoarthritis from the Swedish Hip Arthroplasty Registry for model derivation and internal validation, as well as 125,428 patients from England and Wales recorded in the National Joint Register for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey (NJR) for external model validation. A model was developed using a bootstrap ranking procedure with a least absolute shrinkage and selection operator (LASSO) logistic regression model combined with piecewise linear regression. Discriminative ability was evaluated by the area under the receiver operating characteristic curve (AUC). Calibration belt plots were used to assess model calibration. RESULTS: A main effects model combining age, sex, American Society for Anesthesiologists (ASA) class, the presence of cancer, diseases of the central nervous system, kidney disease, and diagnosed obesity had good discrimination, both internally (AUC = 0.78, 95% confidence interval (CI) 0.75 to 0.81) and externally (AUC = 0.75, 95% CI 0.73 to 0.76). This model was superior to traditional models based on the Charlson (AUC = 0.66, 95% CI 0.62 to 0.70) and Elixhauser (AUC = 0.64, 95% CI 0.59 to 0.68) comorbidity indices. The model was well calibrated for predicted probabilities up to 5%. CONCLUSION: We developed a parsimonious model that may facilitate individualized risk assessment prior to one of the most common surgical interventions. We have published a web calculator to aid clinical decision-making. Cite this article: Bone Joint J 2021;103-B(3):469-478.

Does the order of total hip replacement and lumbar spinal stenosis surgery influence patient-reported outcomes: An observational register study.

Patients with degenerative hip and lumbar spine disorders requiring surgery in both locations is fairly common in clinical practice. We investigated if the order of total hip replacement (THR) and lumbar spinal stenosis surgery (LSSS) influences patient-reported outcomes (PROs). We used data from the Swedish Hip Arthroplasty Register (SHAR) and the Swedish Spine Register (Swespine), on patients operated with THR and LSSS in years 2002 to 2012. To increase the probability of having symptomatic disorders in both locations at the time of the first surgery, we only included patients with both LSSS and THR performed within 2 years. Linear and logistic regression analyses adjusted for age, sex, preoperative PROs, and time between surgeries were used to investigate the association between order of surgeries and the generic PRO measurements EQ-5D and EQ VAS. Eighty-four patients had THR prior to LSSS and 171 patients LSSS prior to THR. Linear regression showed that LSSS prior to THR was associated with higher EQ-5D index (B = 0.09, 95% confidence interval [CI] 0.03-0.16) and EQ VAS (B = 5.6, 95% CI 0.4-10.9) 1 year after the last surgery. Logistic regression showed that the odds ratio [OR] for not having any problems in the "pain" (OR = 3.0, 95% CI 1.5-6.3) and "anxiety/depression" (OR = 2.3, 95% CI 1.3-4.1) dimensions were higher for LSSS before THR. In our cohort, LSSS before THR was associated with better health-related quality of life outcomes compared to the reverse order. The results from our cohort can be helpful in a clinical situation where the physician gives advice to an individual patient when choosing the order of procedures. However, further studies are necessary in order to confirm these results in other cohorts. At present, standard of care remains that order of surgery should be individualized for each patient, with guidance from the operating surgeons.

A small number of surgeons outside the control-limit: an observational study based on 9,482 cases and 208 surgeons performing primary total hip arthroplasties in western Sweden.

Background and purpose - Feedback programs relating to surgeon levels have been introduced in some orthopedic quality registers around the globe. The aim of an established surgeon feedback program is to help surgeons understand their practice and enable an analysis of their own results. There is no surgeon feedback program in Sweden in the orthopedic quality registers and there is a fear that a feedback system might pinpoint surgeons as poor performers, partly due to patient case mix. As a step prior to the introduction of a future possible feedback program in Sweden, we assessed the variation in the occurrence of adverse events (AE) within 90 days and reoperations within 2 years between surgeons in western Sweden and explored the number of surgeons outside the control-limit following primary total hip arthroplasties (THAs).Patients and methods - Patient data, surgical data, and information on the surgeons, relating to surgeries performed in 2011-2016, were retrieved from 9 publicly funded hospitals in western Sweden. Data from medical hospital records, the Swedish Hip Arthroplasty Register (SHAR) and a regional patient register located in western Sweden were linked to a database. Funnel plots with control-limits based on upper 95% and 99.8% confidence intervals (CI) were used to illustrate the variation between surgeons in terms of the outcome and to explore the number of surgeons outside the control-limit. Both observed and standardized proportions are explored. The definition of surgeons outside the control-limit in the study is a surgeon above the upper 95% CI.Results - The study comprised 9,482 primary THAs due to osteoarthritis performed by 208 surgeons, where 91% of the included primary THAs were performed by orthopedic specialists and 9% by trainees. The mean overall annual volume for all surgeons was 27. The observed overall mean rate for AEs within 90 days for all surgeons was 6.2% (5.8-6.7) and for reoperations within 2 years 1.8% (1.7-2.2). The proportion of surgeons outside the 95% CI was low for both AEs (0-5%) and reoperations within 2 years (0-1%) in 2011-2016. The corresponding numbers were even lower for AEs (0-3%) but similar for reoperations (0-1%) after standardization for differences in case mix. In a sub-analysis when the number of surgeries performed was restricted to more than 10 primary THAs annually to being evaluated, almost half or more of all the surgeons were excluded from the annual analysis. The result of this restriction was that all surgeons outside the control-limit disappeared after standardization for both AEs and reoperations for all the years investigated. Considering the complete period of 6 years, less than 1% (1 high-volume surgeon for AEs and 2 high-volume surgeons for reoperations) after risk adjustments were outside the 95% CI, and no surgeons were outside the 99.8% CI.Interpretation - In a Swedish setting, the variation in surgeon performance, as measured by AEs within 90 days and reoperations within 2 years following primary THA, was small and 3% or less of the surgeons were outside the 95% CI for the investigated years after adjustments for case mix. The risk for an individual surgeon to be regarded as having poor performance when creating surgeon-specific feedback in the SHAR is very low when volume and patient risk factors are considered.

Are the First or the Second Hips of Staged Bilateral THAs More Similar to Unilateral Procedures? A Study from the Swedish Hip Arthroplasty Register.

BACKGROUND: Bilateral THAs performed in the same patient should not be considered independent observations, neither biologically nor statistically. As a result, when surgical results are reviewed, it is common to analyze only the first of the two hips, assuming that the first, and not the second hip of a staged bilateral THA, better resembles unilateral THAs. This assumption has not been empirically justified.Question/purposes (1) In patients with staged bilateral THA, is the first or second hip more similar to a unilateral THA in terms of age at surgery, presence of any preoperative Charlson comorbidity, and risk of postoperative reoperation? (2) Should the date of a first or second hip surgery of a staged bilateral THA be used as a starting point for patient survival to better resemble patients with unilateral THA? METHODS: We identified 68,357 THAs due to osteoarthritis in 63,613 patients from the Swedish Hip Arthroplasty Register (SHAR) in 1999-2015. Of those THAs, 14,780 concerned the first hip of a staged bilateral procedure performed between 1999 and 2004; 28,542 were unilaterals from 2004 to 2008, and 25,035 concerned the second hip of a staged bilateral procedure performed 2008 to 2015. We excluded patients who underwent one-stage bilateral THAs. We used different inclusion periods to distinguish unilateral procedures from the first and second hips from staged bilateral procedures because sufficiently long set-up and follow-up periods were needed before and after each period to identify possible contralateral THAs. This introduced potential period confounding, meaning that possible group differences might not be distinguished from unrelated outcome differences over time. We investigated if such time trends existed. It did not for age and reoperation rates, but it did for comorbidity and patient survival. Our primary study endpoint was whether patients with unilateral THAs were more similar to patients with a first hip of a staged bilateral THA, or to patients with their second hip operated. We used Student's t-test to compare mean age at surgery. The proportion of patients with at least one presurgery Charlson comorbidity were compared by 95% bootstrap confidence intervals, after subtracting the yearly time-trend to avoid period confounding. Postoperative risks of reoperation were compared by log-rank tests of Kaplan-Meier curves and by comparing 5-year reoperation rates by pair-wise 95% CIs. Our secondary study endpoint was to compare patient survival for patients with a unilateral THA, a first hip of a staged bilateral THA, or a second hip of a staged bilateral THA. We evaluated this by relative 5-year survival, comparing patients of each group with the general Swedish population of the same age, sex, and year of birth. This way, possible survival differences would be less likely explained by period confounding. RESULTS: Patients undergoing unilateral THA were older than those undergoing a first hip of a staged bilateral THA (70 ± 10 versus 66 ± 9 years, mean difference of 4; p < .001), but they were not different from patients undergoing the second hip of a staged bilateral THA (70 ± 9 years, mean difference of 0; p = 0.74). The period-adjusted proportion of patients with unilateral THA and presurgery comorbidity (Charlson index > 0) was 20% (95% CI: 19.8-20.7). This was no different from patients with a second hip from a staged bilateral THA (20%; 19.7-20.6), but higher compared to patients with a first hip of a staged bilateral THA (15%; 14.5-15.4). For reoperation rates, the log-rank tests showed no difference between unilateral THAs and the second hips of staged bilateral THAs ((Equation is included in full-text article.)). Such difference was found for unilaterals compared with the first hips of staged bilateral THAs ((Equation is included in full-text article.)). The Kaplan-Meier estimate of reoperation rates at 5 years after surgery were also no different for the unilateral THAs compared with the second hips of staged bilateral THAs (3% [95% CI 2.8 to 3.2] for both groups). It was lower (2% [95% CI 1.8 to 2.3]) for a first hip of a staged bilateral THA. For the secondary outcome, the relative 5-year survival differed for all groups. It was 105% (95% CI 104.9 to 105.9) for patients with unilateral THA, 107% (95% CI 106.3 to 107.4) for patients with a second hip from a staged bilateral THA and 109% (95% CI 108.8 to 109.5) for patients with a first hip of a staged bilateral THA. Patients with only a first hip of a planned staged bilateral THA who did not survive long enough to undergo their second THA were classified as unilaterals. The rank-order of survival curves are therefore by design ("immortal time bias"). We conclude, however, that survival for patients with unilateral THA more closely resembles the survival of patients with a second hip of a staged bilateral THA, compared with the first. CONCLUSIONS: Our findings, which are based on observational register data, challenge the common practice in epidemiologic studies of analyzing only the first hip of a staged bilateral THA. We recommend analyzing the second THA in a patient who has undergone staged bilateral THA rather than the first because the second procedure better resembles unilateral THA. LEVEL OF EVIDENCE: Level III, therapeutic study.

More hip complications after total hip arthroplasty than after hemi-arthroplasty as hip fracture treatment: analysis of 5,815 matched pairs in the Swedish Hip Arthroplasty Register.

Background and purpose - Total hip arthroplasty (THA) is increasing as treatment of displaced femoral neck fractures. Several studies compare hemiarthroplasty (HA) with THA, but results vary and few studies report on medical complications. We examined the outcome of THA and HA with a focus on medical complications, hip complications, and death.Patients and methods - Data from the Swedish Hip Arthroplasty Register on 30,953 acute hip fracture patients treated with cemented THA or HA in 2005-2011 were cross-matched with Statistics Sweden for socioeconomic data and with the National Patient Register for diagnostic codes representing medical complications within 180 days or hip complications within the study period. Propensity score matching was used to create comparable groups based on age, sex, income, level of education, marital status, Elixhauser index, and year of surgery. Logistic regression models were created for each outcome.Results - 81% were treated with HA, 73% and 71% were female (HA and THA respectively). Matching resulted in 2 groups of 5,815 patients each. THA was associated with fewer medical complications (OR = 0.83; 95% CI 0.76-0.91) and lower 1-year mortality (OR = 0.42; CI 0.38-0.48), but more hip complications (OR = 1.31; CI 1.20-1.43).Interpretation - THA as treatment of hip fracture was associated with more hip-related complications than HA. The results on mortality and medical complications are, rather, influenced by residual confounding than by the implant design per se. An expansive use of THAs for hip fracture treatment, at the expense of HAs, is not recommended based on our findings if hip complications are to be avoided.

ASA class is associated with early revision and reoperation after total hip arthroplasty: an analysis of the Geneva and Swedish Hip Arthroplasty Registries.

Background and purpose - Data from several joint replacement registries suggest that the rate of early revision surgery after primary total hip arthroplasty (THA) is increasing. The ASA class, now widely recorded in arthroplasty registries, may predict early revision. We investigated the influence of ASA class on the risk of revision and other reoperation within 3 months and within 5 years of primary THA. Patients and methods - We used data from the Geneva and Swedish Hip Arthroplasty Registries, on primary elective THAs performed in 1996-2016 and 2008-2016, respectively. 5,319 and 122,241 THAs were included, respectively. Outcomes were all-cause revision and other reoperations evaluated using Kaplan-Meier survival and Cox regression analyses. Results - Within 3 months after surgery, higher ASA class was associated with greater risk of revision and other reoperation. 3-month cumulative incidences of revision by ASA class I, II, and III-IV respectively, were 0.6%, 0.7%, and 2.3% in Geneva and 0.5%, 0.8%, and 1.6% in Sweden. 3-month cumulative incidences of other reoperation were 0.4%, 0.7%, and 0.9% in Geneva and 0.2%, 0.4%, and 0.7% in Sweden. Adjusted hazard ratios (ASA III-IV vs. I) for revision within 3 months were 2.7 (95% CI 1.2-5.9) in Geneva and 3.3 (CI 2.6-4.0) in Sweden. Interpretation - Assessment of ASA class of patients prior to THA will facilitate risk stratification. Targeted risk-reduction strategies may be appropriate during the very early postoperative period for patients identified as at higher risk. Systematically recording ASA class in arthroplasty registries will permit risk adjustment and facilitate comparison of revision rates internationally.

Is Parkinson's Disease Associated with Increased Mortality, Poorer Outcomes Scores, and Revision Risk After THA? Findings from the Swedish Hip Arthroplasty Register.

BACKGROUND: Neurological conditions such as Parkinson's disease are commonly accepted as a risk factor for an increased likelihood of undergoing revision surgery or death after THA. However, the available evidence for an association between Parkinson's disease and serious complications or poorer patient-reported outcomes after THA is limited and contradictory. QUESTIONS/PURPOSES: (1) Do patients with a preoperative diagnosis of Parkinson's disease have an increased risk of death after elective THA compared with a matched control group of patients? (2) After matching for patient- and surgery-related factors, do revision rates differ between the patients with Parkinson's disease and the matched control group? (3) Are there any differences in patient-reported outcome measures for patients with Parkinson's disease compared with the matched control group? METHODS: Data were derived from a merged database with information from the Swedish Hip Arthroplasty Register and administrative health databases. We identified all patients with Parkinson's disease who underwent THA for primary osteoarthritis between January 1, 1999 and December 31, 2012 (n = 490 after exclusion criteria applied). A control group was generated through exact one-to-one matching for age, sex, Charlson comorbidity index, surgical approach, and fixation method. Risk of death and revision were compared between the groups using Kaplan-Meier and log-rank testing. Patient-reported outcome measures (PROMs), routinely recorded as EQ-5D, EQ VAS, and pain VAS, were measured at the preoperative visit and at 1-year postoperatively; mean absolute values for PROM scores and change in scores over time were compared between the two groups. RESULTS: The risk of death did not differ at 90 days (control group risk = 0.61%; 95% CI = 0.00-1.3; Parkinson's disease group risk = 0.62%; 95% CI = 0.00-1.31; p = 0.998) or 1 year (control group = 2.11%; 95% CI = 0.81-3.39; Parkinson's disease group = 2.56%, 95% CI = 1.12-3.97; p = 0.670). At 9 years, the risk of death was increased for patients with Parkinson's disease (control group = 28.05%; 95% CI = 22.29-33.38; Parkinson's disease group = 54.35%; 95% CI = 46.72-60.88; p < 0.001). The risk of revision did not differ at 90 days (control group = 0.41%; 95% CI = 0.00-0.98; Parkinson's disease group = 1.03%; 95% CI = 0.13-1.92; p = 0.256). At 1 year, the risk of revision was higher for patients with Parkinson's disease (control group = 0.41%; 95% CI = 0.00-0.98; Parkinson's disease group = 2.10%; 95% CIs = 0.80-3.38; p = 0.021). This difference was more pronounced at 9 years (control group = 1.75%; 95% CI = 0.11-3.36; Parkinson's disease group = 5.44%; 95% CI = 2.89-7.91; p = 0.001) when using the Kaplan-Meier method. There was no difference between the control and Parkinson's disease groups for level of pain relief at 1 year postoperatively (mean reduction in pain VAS score for control group = 48.85, SD = 20.46; Parkinson's disease group = 47.18, SD = 23.96; p = 0.510). Mean change in scores for quality of life and overall health from preoperative measures to 1 year postoperatively were smaller for patients in the Parkinson's disease group compared with controls (mean change in EQ-5D scores for control group = 0.42, SD = 0.32; Parkinson's disease group = 0.30, SD = 0.37; p 0.003; mean change in EQ VAS scores for control group = 20.94, SD = 23.63; Parkinson's disease = 15.04, SD = 23.00; p = 0.027). CONCLUSIONS: Parkinson's disease is associated with an increased revision risk but not with short-term mortality rates relevant to assessing risk versus benefit before undergoing THR. The traditional reluctance to perform THR in patients with Parkinson's disease may be too conservative given that the higher long-term risk of death is more likely due to the progressive neurological disorder and not THR itself, and patients with Parkinson's disease report comparable outcomes to controls. Further research on outcomes in THR for patients with other neurological conditions is needed to better address the broader assumptions underlying this traditional teaching.Level of Evidence Level III, therapeutic study.

Association between patient survival following reoperation after total hip replacement and the reason for reoperation: an analysis of 9,926 patients in the Swedish Hip Arthroplasty Register.

Background and purpose - The association between long-term patient survival and elective primary total hip replacement (THR) has been described extensively. The long-term survival following reoperation of THR is less well understood. We investigated the relative survival of patients undergoing reoperation following elective THR and explored an association between the indication for the reoperation and relative survival. Patients and methods - In this observational cohort study we selected the patients who received an elective primary THR and subsequent reoperations during 1999-2017 as recorded in the Swedish Hip Arthroplasty Register. The selected cohort was followed until the end of the study period, censoring or death. The indications for 1st- and eventual 2nd-time reoperations were analyzed and the relative survival ratio of the observed survival and the expected survival was determined. Results - There were 9,926 1st-time reoperations and of these 2,558 underwent further reoperations. At 5 years after the latest reoperation, relative survival following 1st-time reoperations was 0.94% (95% CI 0.93-0.96) and 0.90% (CI 0.87-0.92) following 2nd-time reoperations. At 5 years patients with a 1st-time reoperation for aseptic loosening had higher survival than expected; however, reoperations performed for periprosthetic fracture, dislocation, and infection had lower survival. Interpretation - The relative survival following 1st- and 2nd-time reoperations in elective THR patients differs by reason for reoperation. The impact of reoperation on life expectancy is more obvious for infection/dislocation and periprosthetic fracture.

Relative survival following hemi-and total hip arthroplasty for hip fractures in Sweden.

BACKGROUND: Hip fractures are a common problem in the ageing population. Hip arthroplasty is the common treatment option for displaced intracapsular neck of femur fractures. Even though hip replacements are successful in restoring mobility, reducing pain and diminishing loss of health-related quality of life, the potential impact of a hip fracture on life expectancy as well as the postoperative mortality need consideration. The purpose of this study was to describe the mid-term relative survival rate for a cohort of Swedish patients whom underwent total- or hemiarthroplasty surgery following hip fracture. We also explored whether the survival rate is prosthesis-type specific and influenced by comorbidities, sex, socioeconomic and surgical factors. METHODS: Using prospectively collected information of the Swedish Hip Arthroplasty Register-linked database we identified 43,891 patients operated between 2005 and 2012. Patient- and surgery-specific data in combination with socio-economic data were available for this analysis. We studied relative survival rate and used multivariable modelling with Cox Proportional Hazards Model in Transformed Time. RESULTS: Compared to the Swedish general population the baseline excess hazard was very high in the first half year after the operation, thereafter the excess hazard decreased but remained non-negligible through the 8 years' follow-up period. The mortality rate of males was higher compared to women. Higher Elixhauser comorbidity index (ECI) was associated with worsening survival. However, patients who had ECI = 0 had higher mortality than patients with ECI =1 the first 420 days post fracture. Patients with a hemiarthroplasty had a worse survival than patients with a total hip arthroplasty. Of the hospital types considered university hospitals had lower survival rate. Younger patients had a greater loss of expected life span than patients who suffer hip fracture in their more advanced ages. CONCLUSIONS: Swedish hip fracture patients who undergo arthroplasty surgery had a high excess hazard of dying in the first half year following surgery, and this excess hazard never subsided to negligible levels at least up to 8 years after surgery. Interestingly having no prior record of illnesses worsened the initial mortality. Men living alone had the highest long-term excess mortality.

No increase in readmissions or adverse events after implementation of fast-track program in total hip and knee replacement at 8 Swedish hospitals: An observational before-and-after study of 14,148 total joint replacements 2011-2015.

Background and purpose - Fast-track care programs in elective total hip and knee replacement (THR/TKR) have been introduced in several countries during the last decade resulting in a significant reduction of hospital stay without any rise in readmissions or early adverse events (AE). We evaluated the risk of readmissions and AE within 30 and 90 days after surgery when a fast-track program was introduced in routine care of joint replacement at 8 Swedish hospitals. Patients and methods - Fast-track care programs were introduced at 8 public hospitals in Västra Götaland region from 2012 to 2014. We obtained data from the Swedish Hip and Knee Arthroplasty Registers for patients operated with THR and TKR in 2011-2015. All readmissions and new contacts with the health care system within 3 months with a possible connection to the surgical intervention were requested from the regional patient register. We compared patients operated before and after the introduction of the fast-track program. Results - Implementation of the fast-track program resulted in a decrease in median hospital length of stay (LOS) from 5 to 3 days in both THR and TKR. The total readmission rate <90 days for THR was 7.2% with fast-track compared with 6.7% in the previous program, and for TKR 8.4% in both groups. Almost half of the readmissions occurred without any AE identified. There was no statistically significant difference concerning readmissions or AE when comparing the programs. Interpretation - Implementation of a fast-track care program in routine care of elective hip and knee replacement is effective in reducing hospital stay without increasing the risk of readmissions or adverse events within 90 days after surgery.

Risk of further surgery on the same or opposite side and mortality after primary total hip arthroplasty: A multi-state analysis of 133,654 patients from the Swedish Hip Arthroplasty Register.

Background and purpose - The hip-related timeline of patients following a total hip arthroplasty (THA) can vary. Ideally patients will live their life without need for further surgery; however, some will undergo replacement on the contralateral hip and/or reoperations. We analyzed the probability of mortality and further hip-related surgery on the same or contralateral hip. Patients and methods - We performed a multi-state survival analysis on a prospectively followed cohort of 133,654 Swedish patients undergoing an elective THA between 1999 and 2012. The study used longitudinally collected information from the Swedish Hip Arthroplasty Register and administrative databases. The analysis considered the patients' sex, age, prosthesis type, surgical approach, diagnosis, comorbidities, education, and civil status. Results - During the study period patients were twice as likely to have their contralateral hip replaced than to die. However, with passing time, probabilities converged and for a patient who only had 1 non-revised THA at 10 years, there was an equal chance of receiving a second THA and dying (24%). It was 8 times more likely that the second hip would become operated with a primary THA than that the first hip would be revised. Multivariable regression analysis reinforced the influence of age at operation, sex, diagnosis, comorbidity, and socioeconomic status influencing state transition. Interpretation - Multi-state analysis can provide a comprehensive model of further states and transition probabilities after an elective THA. Information regarding the lifetime risk for bilateral surgery, revision, and death can be of value when discussing the future possible outcomes with patients, in healthcare planning, and for the healthcare economy.

Patients with a previous total hip replacement experience less reduction of back pain following lumbar back surgery.

The coexistence of degenerative disorders from the hip joint and the lumbar spine, known as "the hip-spine syndrome," is a common encounter in clinical practice. These degenerative conditions may cause similar symptoms which often entail diagnostic challenges in determining the origin of pain. Lumbar back surgery (LBS) with fusion and/or decompression, and total hip replacement (THR) are both often successful interventions. However, the knowledge is limited about the post-operative patient-reported outcome (PRO) following LBS in the presence of a prior THR. The aims of this study were to compare 1-year post-operative patient-reported outcome measures (PROMs) following lumbar back surgery (LBS) in patients with and without a prior total hip replacement (THR). Data from Swespine and the Swedish Hip Arthroplasty Register were linked in order to identify the study group of patients with THR prior to LBS. The study group (n = 220) and a matched control group (n = 220) with isolated LBS was defined by using a step-wise selection process. Linear- and logistic regression analyses adjusted for age, sex and pre-operative PROMs demonstrated that THR prior to LBS was associated with worse back-pain (VAS) at 1-year follow-up (B = 5.3, 95%CI: 0.3;10.3). However, previous THR did not influence the EQ-5D index (B = 0.01, 95%CI: -0.05;0.06), EQ VAS (B = -3.0, 95%CI: -6.9;1.0), leg pain (B = 1.5, 95%CI: -4.0;7.0), Oswestry Disability Index (B = 2.6, 95%CI: -0.5;5.6) or satisfaction (OR = 1.1, 97.5%CI 0.7;1.6). This knowledge is important to communicate prior to LBS in order to set proper expectations on surgical outcomes. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2484-2490, 2018.

Can patient-reported outcomes predict re-operations after total hip replacement?

PURPOSE: We investigated if patient-reported outcomes (PROMs) one year after total hip replacement (THR) can predict the risk of re-operation using data from the Swedish Hip Arthroplasty Register. METHODS: A total of 75,899 patients with THR due to osteoarthritis operated in 2002-2014 were included. We used Kaplan-Meier and Cox regression to investigate the relationship between one-year post-operative PROMs and risk of re-operation (all types of further hip surgery). The predictive power of the model and post-operative PROMs were evaluated by concordance index (C). RESULTS: Kaplan-Meier estimates for not being re-operated at eight years was 95.5% (95%CI; 95.3-95.8). Cox regression analyses showed that all PROMs, except for EQ-VAS, were associated with re-operation. The full model had a concordance index of 0.68. Satisfaction (C = 0.65) and pain (C = 0.65) in isolation had the highest predictive power. CONCLUSIONS: Worse PROMs predicted higher risk of re-operation. Therefore, we believe PROMs may be helpful in identifying patients at risk for re-operation and timely address their problems.

Trends in hip replacements between 1999 and 2012 in Sweden.

National Registers document changes in the circumstance, practice, and outcome of surgery with the passage of time. In the context of total hip replacement (THR), registers can help elucidate the relevant factors that affect the clinical outcome. We evaluated the evolution of factors related to patient, surgical procedure, socio-economy, and various outcome parameters after merging databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length-of-stay, mortality rate, adverse events, re-operation and revision rates, and Patient Reported Outcome Measures (PROMs). Throughout this time period the majority of patients were operated on with a diagnosis of primary osteoarthritis. Comorbidity indices increased each year observed. The share of all-cemented implants has dropped from 92% to 68%. More than 88% of the bearings were metal-on-polyethylene. Length-of-stay decreased by 50%. There was a reduction in 30- and 90-day mortality. Re-operation and revision rates at 2 years are decreasing. The post-operative PROMs improved despite the observation of worse pre-operative pain scores getting over time. The demographics of patients receiving a THR, their comorbidities, and their primary diagnosis are changing. Notwithstanding these changes, outcomes like mortality, re-operations, revisions, and PROMs have improved. The practice of hip arthroplasty has evolved, even in a country such as Sweden that is considered to be conservative with regard taking on new surgical practices. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:432-442, 2018.

Comorbidity does not predict long-term mortality after total hip arthroplasty.

Background and purpose - In-hospital death following total hip arthroplasty (THA) is related to comorbidity. The long-term effect of comorbidity on all-cause mortality is, however, unknown for this group of patients and it was investigated in this study. Patients and methods - We used data from the Swedish Hip Arthroplasty Register, linked to the National Patient Register from the National Board of Health and Welfare, for patients operated on with THA in 1999-2012. We identified 120,836 THAs that could be included in the study. We evaluated the predictive power of the Charlson and Elixhauser comorbidity indices on mortality, using concordance indices calculated after 5, 8, and 14 years after THA. Results - All comorbidity indices performed poorly as predictors, in fact worse than a base model with age and sex only. Elixhauser was, however, the least bad choice and it predicted mortality with concordance indices 0.59, 0.58, and 0.56 for 5, 8, and 14 years after THA. Interpretation - Comorbidity indices are poor predictors of long-term mortality after THA.