LÖYDÖKSET METALLIREAKTIOEPÄILYN VUOKSI UUSINTALEIKATUISSA LONKAN METALLI-METALLITEKONIVELISSÄ

Asiasanat:tekonivel, magneettikuvaus, kromi, koboltti, Oxford Hip Scor

Prediction model for an early revision for dislocation after primary total hip arthroplasty

Dislocation is one of the most common complications after primary total hip arthroplasty (THA). Several patient-related risk factors for dislocation have been reported in the previous literature, but only few prediction models for dislocation have been made. Our aim was to build a prediction model for an early (within the first 2 years) revision for dislocation after primary THA using two different statistical methods. The study data constituted of 37 pre- or perioperative variables and postoperative follow-up data of 16 454 primary THAs performed at our institution in 2008–2021. Model I was a traditional logistic regression model and Model II was based on the elastic net method that utilizes machine learning. The models’ overall performance was measured using the pseudo R2 values. The discrimination of the models was measured using C-index in Model I and Area Under the Curve (AUC) in Model II. Calibration curves were made for both models. At 2 years postoperatively, 95 hips (0.6% prevalence) had been revised for dislocation. The pseudo R2 values were 0.04 in Model I and 0.02 in Model II indicating low predictive capability in both models. The C-index in Model I was 0.67 and the AUC in Model II was 0.73 indicating modest discrimination. The prediction of an early revision for dislocation after primary THA is difficult even in a large cohort of patients with detailed data available because of the reasonably low prevalence and multifactorial nature of dislocation. Therefore, the risk of dislocation should be kept in mind in every primary THA, whether the patient has predisposing factors for dislocation or not. Further, when conducting a prediction model, sophisticated methods that utilize machine learning may not necessarily offer significant advantage over traditional statistical methods in clinical setup.publishedVersionPeer reviewe

Implant survival of 662 dual-mobility cups and 727 constrained liners in primary THA: small femoral head size increases the cumulative incidence of revision

Background and purpose - In total hip arthroplasty (THA), the risk for dislocation can be reduced using either dual-mobility cups (DMCs) or constrained liners (CLs). There are few studies comparing these concepts in primary THA. Therefore, we compared the cumulative incidence of revision in primary THA patients treated with DMC or CL with varying head sizes with conventional THA patients as reference group. Patients and methods - We performed a cohort study based on the Finnish arthroplasty register, comparing DMCs and CLs operated over the period 2000-2017. DMCs were divided into 2 groups based on the implant design: "DMC Trident" group (n = 399) and "DMC Others" group (n = 263). CLs were divided based on the femoral head size: "CL 36 mm" group (n = 425) and "CL < 36 mm" group (n = 302). All conventional primary THAs operated on in 2000-2017 with 28-36 mm femoral head were included as control group ("Conventional THA" group, n = 102,276). Implant survival was calculated by the corresponding cumulative incidence function with revision as the endpoint and death as competing event. Also, the prevalence of different reasons for revision was compared. Results - The 6-year cumulative incidence function estimates for the first revision were 6.9% (95% CI 4.0-9.7) for DMC Trident, 5.0% (CI 1.5-8.5) for DMC Others, 13% (CI 9.3-17) for CL < 36 mm, 6.3% (3.7-8.9) for CL 36 mm, and 4.7% (CI 4.5-4.8) for control group (conventional THA). The prevalence of dislocation revision was high (5.0%, CI 2.9-8.2) in the CL < 36 mm group compared with other groups. Interpretation - The DMC and CL 36 mm groups had promising mid-term survival rates, comparable to those of primary conventional THA group. The revision rate of CLs with < 36 mm head was high, mostly due to high prevalence of dislocation revisions. Therefore, CLs with 36 mm femoral head should be preferred over smaller ones

Randomized controlled trials in de-implementation research : a systematic scoping review

Background: Healthcare costs are rising, and a substantial proportion of medical care is of little value. De-implementation of low-value practices is important for improving overall health outcomes and reducing costs. We aimed to identify and synthesize randomized controlled trials (RCTs) on de-implementation interventions and to provide guidance to improve future research. Methods: MEDLINE and Scopus up to May 24, 2021, for individual and cluster RCTs comparing de-implementation interventions to usual care, another intervention, or placebo. We applied independent duplicate assessment of eligibility, study characteristics, outcomes, intervention categories, implementation theories, and risk of bias. Results: Of the 227 eligible trials, 145 (64%) were cluster randomized trials (median 24 clusters; median follow-up time 305 days), and 82 (36%) were individually randomized trials (median follow-up time 274 days). Of the trials, 118 (52%) were published after 2010, 149 (66%) were conducted in a primary care setting, 163 (72%) aimed to reduce the use of drug treatment, 194 (85%) measured the total volume of care, and 64 (28%) low-value care use as outcomes. Of the trials, 48 (21%) described a theoretical basis for the intervention, and 40 (18%) had the study tailored by context-specific factors. Of the de-implementation interventions, 193 (85%) were targeted at physicians, 115 (51%) tested educational sessions, and 152 (67%) multicomponent interventions. Missing data led to high risk of bias in 137 (60%) trials, followed by baseline imbalances in 99 (44%), and deficiencies in allocation concealment in 56 (25%). Conclusions: De-implementation trials were mainly conducted in primary care and typically aimed to reduce low-value drug treatments. Limitations of current de-implementation research may have led to unreliable effect estimates and decreased clinical applicability of studied de-implementation strategies. We identified potential research gaps, including de-implementation in secondary and tertiary care settings, and interventions targeted at other than physicians. Future trials could be improved by favoring simpler intervention designs, better control of potential confounders, larger number of clusters in cluster trials, considering context-specific factors when planning the intervention (tailoring), and using a theoretical basis in intervention design. Registration: OSF Open Science Framework hk4b2.Peer reviewe

Randomized controlled trials in de-implementation research : a systematic scoping review

Background: Healthcare costs are rising, and a substantial proportion of medical care is of little value. De-implementation of low-value practices is important for improving overall health outcomes and reducing costs. We aimed to identify and synthesize randomized controlled trials (RCTs) on de-implementation interventions and to provide guidance to improve future research. Methods: MEDLINE and Scopus up to May 24, 2021, for individual and cluster RCTs comparing de-implementation interventions to usual care, another intervention, or placebo. We applied independent duplicate assessment of eligibility, study characteristics, outcomes, intervention categories, implementation theories, and risk of bias. Results: Of the 227 eligible trials, 145 (64%) were cluster randomized trials (median 24 clusters; median follow-up time 305 days), and 82 (36%) were individually randomized trials (median follow-up time 274 days). Of the trials, 118 (52%) were published after 2010, 149 (66%) were conducted in a primary care setting, 163 (72%) aimed to reduce the use of drug treatment, 194 (85%) measured the total volume of care, and 64 (28%) low-value care use as outcomes. Of the trials, 48 (21%) described a theoretical basis for the intervention, and 40 (18%) had the study tailored by context-specific factors. Of the de-implementation interventions, 193 (85%) were targeted at physicians, 115 (51%) tested educational sessions, and 152 (67%) multicomponent interventions. Missing data led to high risk of bias in 137 (60%) trials, followed by baseline imbalances in 99 (44%), and deficiencies in allocation concealment in 56 (25%). Conclusions: De-implementation trials were mainly conducted in primary care and typically aimed to reduce low-value drug treatments. Limitations of current de-implementation research may have led to unreliable effect estimates and decreased clinical applicability of studied de-implementation strategies. We identified potential research gaps, including de-implementation in secondary and tertiary care settings, and interventions targeted at other than physicians. Future trials could be improved by favoring simpler intervention designs, better control of potential confounders, larger number of clusters in cluster trials, considering context-specific factors when planning the intervention (tailoring), and using a theoretical basis in intervention design. Registration: OSF Open Science Framework hk4b2.Peer reviewe

Randomized controlled trials in de-implementation research : a systematic scoping review

Background: Healthcare costs are rising, and a substantial proportion of medical care is of little value. De-implementation of low-value practices is important for improving overall health outcomes and reducing costs. We aimed to identify and synthesize randomized controlled trials (RCTs) on de-implementation interventions and to provide guidance to improve future research. Methods: MEDLINE and Scopus up to May 24, 2021, for individual and cluster RCTs comparing de-implementation interventions to usual care, another intervention, or placebo. We applied independent duplicate assessment of eligibility, study characteristics, outcomes, intervention categories, implementation theories, and risk of bias. Results: Of the 227 eligible trials, 145 (64%) were cluster randomized trials (median 24 clusters; median follow-up time 305 days), and 82 (36%) were individually randomized trials (median follow-up time 274 days). Of the trials, 118 (52%) were published after 2010, 149 (66%) were conducted in a primary care setting, 163 (72%) aimed to reduce the use of drug treatment, 194 (85%) measured the total volume of care, and 64 (28%) low-value care use as outcomes. Of the trials, 48 (21%) described a theoretical basis for the intervention, and 40 (18%) had the study tailored by context-specific factors. Of the de-implementation interventions, 193 (85%) were targeted at physicians, 115 (51%) tested educational sessions, and 152 (67%) multicomponent interventions. Missing data led to high risk of bias in 137 (60%) trials, followed by baseline imbalances in 99 (44%), and deficiencies in allocation concealment in 56 (25%). Conclusions: De-implementation trials were mainly conducted in primary care and typically aimed to reduce low-value drug treatments. Limitations of current de-implementation research may have led to unreliable effect estimates and decreased clinical applicability of studied de-implementation strategies. We identified potential research gaps, including de-implementation in secondary and tertiary care settings, and interventions targeted at other than physicians. Future trials could be improved by favoring simpler intervention designs, better control of potential confounders, larger number of clusters in cluster trials, considering context-specific factors when planning the intervention (tailoring), and using a theoretical basis in intervention design. Registration: OSF Open Science Framework hk4b2.publishedVersionPeer reviewe

Blood Metal Ion Thresholds to Identify Patients with Metal-on-Metal Hip Implants at Risk of Adverse Reactions to Metal Debris

Background: The authors of recent studies have reported newly devised implant-specific blood metal ion thresholds to predict adverse reactions to metal debris (ARMD) in patients who have undergone unilateral or bilateral metal-on-metal (MoM) hip arthroplasty. These thresholds were most effective for identifying patients at low risk of ARMD. We investigated whether these newly devised blood metal ion thresholds could effectively identify patients at risk of ARMD after MoM hip arthroplasty in an external cohort of patients. Methods: We performed a validation study involving 803 MoM hip arthroplasties (323 unilateral Birmingham Hip Resurfacing [BHR], 93 bilateral BHR, and 294 unilateral Corail-Pinnacle implants) performed in 710 patients at 3 European centers. All patients underwent whole-blood metal ion sampling, and were divided into 2 groups: those with ARMD (leading to revision or identified on imaging; n = 75) and those without ARMD (n = 635). Previously devised implant-specific blood metal ion thresholds (2.15 μg/L of cobalt for unilateral BHR; 5.5 μg/L for the maximum of either cobalt or chromium for bilateral BHR; and 3.57 μg/L of cobalt for unilateral Corail-Pinnacle implants) were applied to the validation cohort, and receiver operating characteristic curve analysis was used to establish the discriminatory characteristics of each threshold. Results: The area under the curve, sensitivity, specificity, and positive and negative predictive values for the ability of each implant-specific threshold to distinguish between patients with and without ARMD were, respectively, 89.4% (95% confidence interval [CI] = 82.8% to 96.0%), 78.9%, 86.7%, 44.1%, and 96.9% for unilateral BHR; 89.2% (CI = 81.3% to 97.1%), 70.6%, 86.8%, 54.5%, and 93.0% for bilateral BHR; and 76.9% (CI = 63.9% to 90.0%), 65.0%, 85.4%, 24.5%, and 97.1% for unilateral Corail-Pinnacle implants. Using the implant-specific thresholds, we missed 20 patients with ARMD (2.8% of the patients in this series). We missed more patients with ARMD when we used the fixed thresholds proposed by regulatory authorities: 35 (4.9%) when we used the U.K. threshold of 7 μg/L for both cobalt and chromium (p = 0.0003), 21 (3.0%) when we used the U.S. threshold of 3 μg/L for both cobalt and chromium (p = 1.0), and 46 (6.5%) when we used the U.S. threshold of 10 μg/L for both cobalt and chromium (p < 0.0001). Conclusions: This external multicenter validation study confirmed that patients with blood metal ion levels below new implant-specific thresholds have a low risk of ARMD after MoM hip arthroplasty. Using these implant-specific thresholds, we missed fewer patients with ARMD compared with when the thresholds currently proposed by regulatory authorities were used. We therefore recommend using implant-specific blood metal ion thresholds when managing patients who have undergone MoM hip arthroplasty. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence

Metallireaktiot lonkan metalli-metalli-liukuparillisissa pinnoite- ja kokotekonivelissä: seuranta, diagnostiikka ja hoito

Perinteiset 1990-luvulla käytössä olleet lonkan metalli-muovi-tekonivelet kuluivat etenkin nuorilla ja liikunnallisesti aktiivisilla potilailla nopeasti, minkä vuoksi näitä tekoniveliä jouduttiin vaihtamaan usein uusintaleikkauksissa. Tämä johti metalli-metalli-liukupintaa (metal-on-metal, MoM) hyödyntävien uusien tekonivelten kehittämiseen ja laajamittaiseen käyttöönottoon. MoM-tekonivelten alustavat tulokset olivat hyviä, mutta usean vuoden käytön jälkeen niihin havaittiin liittyvän tekonivelen pinnasta irronneiden koboltti- ja kromi-ionien aiheuttamia lonkkaa ympäröivien pehmytkudosten muutoksia, niin kutsuttuja metallireaktioita. Tässä väitöskirjassa arvioitiin metallireaktion tutkimisessa käytettävien menetelmien käyttökelpoisuutta sekä metallireaktion vuoksi tehtyjen uusintaleikkausten tuloksia. Väitöskirjatutkimus suoritettiin Tekonivelsairaala Coxassa 2011-2016. Tutkimuksessa määritettiin riskitekijöitä kohonneille veren koboltti- ja kromipitoisuuksille, arvioitiin magneettikuvauksen ja ultraäänen käyttökelpoisuutta MoM-tekoniveliin liittyvien pehmytkudosmuutosten tunnistamisessa sekä tutkittiin MoM-tekonivelen uusintaleikkauksen vaikutusta veren metalli-ionipitoisuuksiin sekä potilaiden oireisiin. Väitöskirjan ensimmäisessä osatyössä havaittiin erityisesti varrellisiin suurinupillisiin MoM-tekoniveliin liittyvän kohonneita veren koboltti- ja kromi-ionipitoisuuksia. Varrellisissa MoM-tekonivelissä riskiä kohonneille metalli-ionipitoisuuksille lisäsivät naissukupuoli, suuri komponentin koko sekä leikkauksesta kulunut aika. MoM-pinnoitetekonivelen saaneilla potilailla riskiä lisäsivät pieni komponentin koko, korkea kuppikomponentin kallistuskulma sekä potilaan nuori ikä. Toisessa ja kolmannessa osatyössä sekä magneetti- että ultraäänikuvantamisen todettiin olevan käyttökelpoisia menetelmiä metallireaktioiden havaitsemisessa, eikä omien tuloksiemme ja kirjallisuuden perustella kumpaakaan voida nostaa yksiselitteisesti toisen yläpuolelle. Vuotta vanhempien kuvantamistutkimusten totesimme olevan epäluotettavia, eikä niiden käyttöä suositella päätöksenteossa tai uusintaleikkauksen suunnittelussa. Väitöskirjan neljännessä osatyössä havaittiin, että MoM-tekonivelen saaneiden potilaiden systemaattinen seuranta paljastaa paljon oireettomia metallireaktiota ja johtaa lisääntyneeseen uusintaleikkausten määrään. Viidennessä osatyössä taas havaittiin, että metallireaktion vuoksi tehdyn uusintaleikkauksen jälkeen veren metalli-ionipitoisuudet pienenivät, mutta osalle potilaista jäi edelleen merkittävissä määrin oireita. Vaikka väitöskirjatyö vastasikin useisiin kysymyksiin, herätti se myös uusia kysymyksiä. Ketkä potilaat hyötyvät uusintaleikkauksesta, keiden kohdalla seuranta olisi parempi vaihtoehto, ja mitkä ovat ne vaikeaa kudostuhoa ennustavat löydökset, joiden perusteella oireettomalle potilaallekin kannattaa tehdä uusintaleikkaus? Tulevaisuudessa on tärkeää arvioida eri hoitovaihtoehtojen hyötyjä ja haittoja MoM-tekonivelen saaneilla potilailla, ja kehittää nykyistä yksilöllisemmin räätälöityjä seuranta- ja hoitosuosituksia parhaan lopputuloksen saavuttamiseksi.High hopes were placed on the third generation metal-on-metal (MoM) hip replacements, as they were considered to be an excellent option for young and physically active patients for whom the conventional metal-on-polyethylene (MoP) hip replacement was not durable enough. The problem with MoP replacements was the high rates of polyethylene wear and the osteolysis associated with wear debris. Over one million MoM hips were implanted in the 2000s. Unfortunately, higher than anticipated revision rates were reported for hip resurfacings in the Australian Orthopaedic Association National Joint Registry Annual Report 2007, in addition to several individual centers writing case reports about periprosthetic soft tissue abnormalities related to pain and implant failure. The term Adverse Reaction to Metal Debris (ARMD) was created to describe these soft tissue lesions related to the increased wear of metallic bearing surfaces and the inflammatory reaction to metal debris. Around the world, orthopaedic hospitals launched screening programs in order to detect these new types of abnormalities with the help of clinical examination, plain radiographs, whole blood cobalt (Co) and chromium (Cr) measurements and cross-sectional imaging. The aim of this thesis is to evaluate the usefulness of diagnostic tools used to detect ARMD, and to investigate the effects of the systematic screening program and operative treatment policy at our institution. The aim of study I was to identify the MoM implant brands with a high percentage of elevated whole blood Co and Cr levels, along with the patient and implant-specific risk factors for elevated ion levels. In studies II and III, we sought to determine the sensitivity and specificity of magnetic resonance imaging (MRI) and ultrasound for detecting extracapsular pseudotumors, which are common ARMD-related findings. In study IV, we evaluated the effect of our systematic MoM screening program on the revision rate and number of ARMD cases detected in a cohort of Pinnacle (Depuy Orthopaedics, Warsaw, IN) MoM total hip arthroplasties (THA). Systematic screening of the Pinnacle cohort was launched in January 2012, and our aim was to evaluate the effect of screening by comparing pre- and post-screening statistics. In study V, we determined the effect of the revision surgery on the whole blood Co and Cr levels and hip function. In study I, we found that elevated whole blood metal ion levels (>7 parts per billion, ppb) are more common in large head size MoM THA than in patients with resurfacing (17.4% vs 5.9%, p<0.001). In resurfacings, small femoral head size, high inclination and young age increased the risk for elevated ions, and in THAs the corresponding risk factors were female gender, large femoral head size and long time between surgery and ion measurement. In study II, we found sensitivity of 71% and specificity of 87% for MRI in detecting extracapsular pseudotumors. The sensitivity was significantly lower if more than one year had elapsed since imaging, which would implicate that over one-year-old MRI/ultrasound imaging should not be used to guide clinical decisions. In study III, ultrasound had a sensitivity of 83% and specificity of 92% in the trochanteric region, and 79% and 94% in the iliopsoas region, respectively. In study IV, the launch of the screening program revealed 29 new cases of ARMD decreasing the implant survival rate from 96% (95% confidence interval [95% CI], 95 to 98) to 86% (95% CI, 82 to 90) with only three cases found before the screening. In study V, we noticed a clear decreasing trend towards normal levels in blood Co and Cr levels after the removal of MoM resurfacings and THAs, although Cr remained elevated for several years in a few patients. The median Oxford Hip Score (OHS) improved from the preoperative value to the 1-year postoperative value in the unilateral resurfacing and THA groups. Elevated whole blood metal ion levels are common among MoM hip resurfacings and THAs, and the risk factors for elevated metal ion levels are similar to those for revision surgery. Both MRI and ultrasound provide good accuracy for imaging extracapsular pseudotumors and, based on our results, neither is superior over the other. On the other hand, over one year old cross-sectional imaging should not be used in surgical planning. We observed that systematic screening of MoM hips with blood Co and Cr measurements and cross-sectional imaging reveals a vast number of hips with ARMD. However, it is hard to estimate the true significance of this finding, as the natural history of ARMD is unclear, and it is not certain which patients would benefit most from the surgical intervention and revision of a MoM hip replacement and which patients would benefit from a conservative approach. After all, even though the revision of a MoM implant was an effective procedure to diminish systemic metal ion burden virtually in all patients, many patients were left symptomatic and in some cases the postoperative situation was actually worse than the preoperative one. In future, it is important that the best possible treatments for various grades of ARMD lesions are determined and that stratified guidelines for treatment are created in order to ensure the best possible outcome

LÖYDÖKSET METALLIREAKTIOEPÄILYN VUOKSI UUSINTALEIKATUISSA LONKAN METALLI-METALLITEKONIVELISSÄ

Asiasanat:tekonivel, magneettikuvaus, kromi, koboltti, Oxford Hip Scor