Thyroid hormone induces ossification and terminal maturation in a preserved OA cartilage biomimetic model.

OBJECTIVE: To characterize aspects of triiodothyronine (T3) induced chondrocyte terminal maturation within the molecular osteoarthritis pathophysiology using the previously established T3 human ex vivo osteochondral explant model. DESIGNS: RNA-sequencing was performed on explant cartilage obtained from OA patients (n = 8), that was cultured ex vivo with or without T3 (10 ng/ml), and main findings were validated using RT-qPCR in an independent sample set (n = 22). Enrichment analysis was used for functional clustering and comparisons with available OA patient RNA-sequencing and GWAS datasets were used to establish relevance for OA pathophysiology by linking to OA patient genomic profiles. RESULTS: Besides the upregulation of known hypertrophic genes EPAS1 and ANKH, T3 treatment resulted in differential expression of 247 genes with main pathways linked to extracellular matrix and ossification. CCDC80, CDON, ANKH and ATOH8 were among the genes found to consistently mark early, ongoing and terminal maturational OA processes in patients. Furthermore, among the 37 OA risk genes that were significantly affected in cartilage by T3 were COL12A1, TNC, SPARC and PAPPA. CONCLUSIONS: RNA-sequencing results show that metabolic activation and recuperation of growth plate morphology are induced by T3 in OA chondrocytes, indicating terminal maturation is accelerated. The molecular mechanisms involved in hypertrophy were linked to all stages of OA pathophysiology and will be used to validate disease models for drug testing.

Comorbidity and risk of infection among patients with hip fracture: a Danish population-based cohort study.

Impact of comorbidity on infection risk among hip fracture patients is unclear. We found high incidence of infection. Comorbidity was an important risk factor for infection up to 1 year after surgery. Results indicates a need for additional investment in pre- and postoperative programs that assist patients with high comorbidity. PURPOSE: Comorbidity level and incidence of infection have increased among older patients with hip fracture. The impact of comorbidity on infection risk is unclear. We conducted a cohort study examining the absolute and relative risks of infection in relation to comorbidity level among hip fracture patients. METHODS: Utilizing Danish population-based medical registries, we identified 92,600 patients aged ≥ 65 years undergoing hip fracture surgery between 2004 and 2018. Comorbidity was categorized by Charlson comorbidity index scores (CCI): none (CCI = 0), moderate (CCI = 1-2), or severe (CCI ≥ 3). Primary outcome was any hospital-treated infection. Secondary outcomes were hospital-treated pneumonia, urinary tract infection, sepsis, reoperation due to surgical-site infection (SSI), and a composite of any hospital- or community-treated infection. We calculated cumulative incidence and hazard ratios (aHRs) adjusted for age, sex, and surgery year, including 95% confidence intervals (CIs). RESULTS: Prevalence of moderate and severe comorbidity was 40% and 19%, respectively. Incidence of any hospital-treated infection increased with comorbidity level within 0-30 days (none 13% vs. severe 20%) and 0-365 days (none 22% vs. 37% severe). Patients with moderate and severe comorbidity, compared to no comorbidity, had aHRs of 1.3 (CI: 1.3-1.4) and 1.6 (CI: 1.5-1.7) within 0-30 days, and 1.4 (CI: 1.4-1.5) and 1.9 (CI: 1.9-2.0) within 0-365, respectively. Highest incidence was observed for any hospital- or community-treated infection (severe 72%) within 0-365 days. Highest aHR was observed for sepsis within 0-365 days (severe vs. none: 2.7 (CI: 2.4-2.9)). CONCLUSION: Comorbidity is an important risk factor for infection up to 1 year after hip fracture surgery.

Elbow flexion contractures in neonatal brachial plexus palsy: A one-year comparison of dynamic orthosis and serial casting.

OBJECTIVE: Elbow flexion contractures are common complications of neonatal brachial plexus palsy, but evidence on how to treat these contractures is weak. This study compared the treatment of elbow flexion contractures using a dynamic orthosis or serial circular casting. METHODS: A randomized controlled trial was conducted with one-year follow-up. Children with an elbow flexion contracture of ≥30° were treated with either a night-worn dynamic orthosis for one year or serial casting for four weeks followed by night splinting. For pragmatic reasons, some participants were included in an open part of this study, this group was also analyzed separately. Degree of contracture and goal attainment scaling was evaluated at baseline and after 8, 20 and 54 weeks. RESULTS: 55 patients were analyzed in this trial, 32 of whom were randomized to treatment. At one-year follow-up of the randomized group, both dynamic splinting (median -8.5°, interquartile range [IQR] -13.5, -5) and serial casting (median -11.0°, IQR -16, -5) resulted in significant reduction of contracture (P < 0.001). The reduction was significantly greater with serial casting in the first 20 weeks, but not at one-year follow-up (P = 0.683). In the entire cohort, the individual functional goals had been reached in 24 out of 32 cases (80%) of dynamic splinting and 18 out of 23 cases (82%) of serial casting, respectively. CONCLUSION: The dynamic night orthosis is comparable to serial casting for treating elbow flexion contractures in children with brachial plexus birth injury. We recommend selecting one of these treatment modalities in close consultation with parents and patients.

WWP2 confers risk to osteoarthritis by affecting cartilage matrix deposition via hypoxia associated genes.

OBJECTIVE: To explore the co-expression network of the osteoarthritis (OA) risk gene WWP2 in articular cartilage and study cartilage characteristics when mimicking the effect of OA risk allele rs1052429-A on WWP2 expression in a human 3D in vitro model of cartilage. METHOD: Co-expression behavior of WWP2 with genes expressed in lesioned OA articular cartilage (N = 35 samples) was explored. By applying lentiviral particle mediated WWP2 upregulation in 3D in vitro pellet cultures of human primary chondrocytes (N = 8 donors) the effects of upregulation on cartilage matrix deposition was evaluated. Finally, we transfected primary chondrocytes with miR-140 mimics to evaluate whether miR-140 and WWP2 are involved in similar pathways. RESULTS: Upon performing Spearman correlations in lesioned OA cartilage, 98 highly correlating genes (|ρ| > 0.7) were identified. Among these genes, we identified GJA1, GDF10, STC2, WDR1, and WNK4. Subsequent upregulation of WWP2 on 3D chondrocyte pellet cultures resulted in a decreased expression of COL2A1 and ACAN and an increase in EPAS1 expression. Additionally, we observed a decreased expression of GDF10, STC2, and GJA1. Proteomics analysis identified 42 proteins being differentially expressed with WWP2 upregulation, which were enriched for ubiquitin conjugating enzyme activity. Finally, upregulation of miR-140 in 2D chondrocytes resulted in significant upregulation of WWP2 and WDR1. CONCLUSIONS: Mimicking the effect of OA risk allele rs1052429-A on WWP2 expression initiates detrimental processes in the cartilage shown by a response in hypoxia associated genes EPAS1, GDF10, and GJA1 and a decrease in anabolic markers, COL2A1 and ACAN.

Effectiveness of mechanical cleaning, antibiotics, and induction heating on eradication of Staphylococcus aureus in mature biofilms.

AIMS: Here we used a mature seven-day biofilm model of Staphylococcus aureus, exposed to antibiotics up to an additional seven days, to establish the effectiveness of either mechanical cleaning or antibiotics or non-contact induction heating, and which combinations could eradicate S. aureus in mature biofilms. METHODS: Mature biofilms of S. aureus (ATCC 29213) were grown on titanium alloy (Ti6Al4V) coupons for seven days and were subjected to the following treatments or their combinations: antibiotics, mechanical cleaning, or heat shock by induction heating of 60°C for one minute. Experiments were repeated at least five times. RESULTS: In the untreated biofilm, growth up to 1.8×1011 colony-forming units (CFU)/cm2 was observed. Treatment with ciprofloxacin, flucloxacillin, vancomycin, cefuroxime, and amoxicillin all with rifampicin gave 6.0 log, 6.1 log, 1.4 log, 4.8 log, and 3.6 log reduction in CFU/cm2, respectively. Mechanical cleaning alone resulted in 4.9 log reduction and induction heating in 7.3 log reduction. There was an additional effect of ciprofloxacin, flucloxacillin, and induction heating when used in combinations. There was no additional effect for mechanical cleaning. No bacterial growth could be detected after induction heating followed by seven days of ciprofloxacin with rifampicin. CONCLUSION: Mechanical cleaning, antibiotics, and non-contact induction heating reduced the bacterial load of mature S. aureus biofilms with approximately 5 log or more as a single treatment. The effect of mechanical cleaning on mature S. aureus biofilms was limited when used in combination with antibiotics and/or induction heating.Cite this article: Bone Joint Res 2022;11(9):629-638.

[Partial or full component exchange in hip revision? : The relevance of off-label use and mix & match]. / Partieller oder vollständiger Wechsel in der Hüftrevisionsendoprothetik? : Bedeutung von Off-Label-Anwendung und Mix & Match.

Off-label use is frequently practiced in hip revision arthroplasty, as there may be indications for the application of implants for purposes outside the one the manufacturers intended (i.e. large bone and soft tissue defects, obesity). Patients may also benefit from selective application of mix & match in hip revision, when the exchange of one component only is necessary and the invasiveness of surgery can be reduced. Currently, there are no formal guidelines for these situations. Therefore, within a recent EFORT initiative, evidence- and consensus-based recommendations have been developed for the safe application of off-label use and mix & match in revision hip and knee arthroplasty.

A tailored intervention does not reduce low value MRI's and arthroscopies in degenerative knee disease when the secular time trend is taken into account: a difference-in-difference analysis.

PURPOSE: To evaluate the effectiveness of a tailored intervention to reduce low value MRIs and arthroscopies among patients ≥ 50 years with degenerative knee disease in 13 Dutch orthopaedic centers (intervention group) compared with all other Dutch orthopaedic centers (control group). METHODS: All patients with degenerative knee disease ≥ 50 years admitted to Dutch orthopaedic centers from January 2016 to December 2018 were included. The tailored intervention included participation of clinical champions, education on the Dutch Choosing Wisely recommendation for MRI's and arthroscopies in degenerative knee disease, training of orthopaedic surgeons to manage patient expectations, performance feedback, and provision of a patient brochure. A difference-in-difference analysis was used to compare the time trend before (admitted January 2016-June 2017) and after introduction of the intervention (July 2017-December 2018) between intervention and control hospitals. Primary outcome was the monthly percentage of patients receiving a MRI or knee arthroscopy, weighted by type of hospital. RESULTS: 136,446 patients were included, of whom 32,163 were treated in the intervention hospitals. The weighted percentage of patients receiving a MRI on average declined by 0.15% per month (ß = - 0.15, P < 0.001) and by 0.19% per month for arthroscopy (ß = - 0.19, P < 0.001). However, these changes over time did not differ between intervention and control hospitals, neither for MRI (ß = - 0.74, P = 0.228) nor arthroscopy (ß = 0.13, P = 0.688). CONCLUSIONS: The extent to which patients ≥ 50 years with degenerative knee disease received a MRI or arthroscopy declined significantly over time, but could not be attributed to the tailored intervention. This secular downward time trend may reflect anoverall focus of reducing low value care in The Netherlands. LEVEL OF EVIDENCE: III.

Acute pain after total hip and knee arthroplasty does not affect chronic pain during the first postoperative year: observational cohort study of 389 patients.

Chronic pain is frequently reported after total hip and knee arthroplasties (THA/TKA) in osteoarthritis (OA) patients. We investigated if severity of acute postoperative pain following THA/TKA in OA patients was associated with pain during the first postoperative year. From an observational study, OA patients scheduled for primary THA/TKA (June 2012-December 2017) were included from two hospitals in the Netherlands. Acute postoperative pain scores were collected within 72 h postoperatively and categorized as no/mild (NRS ≤ 4) or moderate/severe (NRS > 4). Pain was assessed preoperatively, 3, 6 and 12 months postoperatively using the HOOS/KOOS subscale pain. With Multilevel Mixed-effects-analyses, we estimated associations between acute and chronic pain until one year postoperative, adjusted for confounders and including an interaction term (Time*Acute pain). 193 THA and 196 TKA patients were included, 29% of THA and 51% of TKA patients reported moderate/severe pain acutely after surgery. In the THA group, the difference in pain at 3 months between the no/mild and moderate/severe groups, was approximately six points, in favor of the no/mild group (95% CI [-12.4 to 0.9]) this difference became smaller over time. In the TKA group we found similar differences, with approximately four points (95% CI [-9.6 to 1.3]) difference between the no/mild and moderate/severe group at 6 months, this difference attenuated at 12 months. No association between severity of acute postoperative pain and pain during the first postoperative year was found. These findings suggest that measures to limit acute postoperative pain will likely not impact development of chronic pain.

Improved clinical investigation and evaluation of high-risk medical devices: the rationale and objectives of CORE-MD (Coordinating Research and Evidence for Medical Devices).

In the European Union (EU) the delivery of health services is a national responsibility but there are concerted actions between member states to protect public health. Approval of pharmaceutical products is the responsibility of the European Medicines Agency, whereas authorizing the placing on the market of medical devices is decentralized to independent 'conformity assessment' organizations called notified bodies. The first legal basis for an EU system of evaluating medical devices and approving their market access was the medical device directives, from the 1990s. Uncertainties about clinical evidence requirements, among other reasons, led to the EU Medical Device Regulation (2017/745) that has applied since May 2021. It provides general principles for clinical investigations but few methodological details-which challenges responsible authorities to set appropriate balances between regulation and innovation, pre- and post-market studies, and clinical trials and real-world evidence. Scientific experts should advise on methods and standards for assessing and approving new high-risk devices, and safety, efficacy, and transparency of evidence should be paramount. The European Commission recently awarded a Horizon 2020 grant to a consortium led by the European Society of Cardiology and the European Federation of National Associations of Orthopaedics and Traumatology, that will review methodologies of clinical investigations, advise on study designs, and develop recommendations for aggregating clinical data from registries and other real-world sources. The CORE-MD project (Coordinating Research and Evidence for Medical Devices) will run until March 2024; here we describe how it may contribute to the development of regulatory science in Europe.

Administration of an adeno-associated viral vector expressing interferon-ß in patients with inflammatory hand arthritis, results of a phase I/II study.

OBJECTIVE: Inflammatory hand arthritis (IHA) results in impaired function. Local gene therapy with ART-I02, a recombinant adeno-associated virus (AAV) serotype 5 vector expressing interferon (IFN)-ß, under the transcriptional control of nuclear factor κ-B responsive promoter, was preclinically shown to have favorable effects. This study aimed to investigate the safety and tolerability of local gene therapy with ART-I02 in patients with IHA. METHODS: In this first-in-human, dose-escalating, cohort study, 12 IHA patients were to receive a single intra-articular (IA) injection of ART-I02 ranging 0.3 × 1012-1.2 × 1013 genome copies in an affected hand joint. Adverse events (AEs), routine safety laboratory and the clinical course of disease were periodically evaluated. Baseline- and follow-up contrast enhanced magnetic resonance images (MRIs), shedding of viral vectors in bodily fluids, and AAV5 and IFN-ß immune responses were evaluated. A data review committee provided safety recommendations. RESULTS: Four patients were enrolled. Long-lasting local AEs were observed in 3 patients upon IA injection of ART-I02. The AEs were moderate in severity and could be treated conservative. Given the duration of the AEs and their possible or probable relation to ART-I02, no additional patients were enrolled. No systemic treatment emergent AEs were observed. The MRIs reflected the AEs by (peri)arthritis. No T-cell response against AAV5 or IFN-ß, nor IFN-ß antibodies could be detected. Neutralizing antibody titers against AAV5 raised post-dose. CONCLUSION: Single IA doses of 0.6 × 1012 or 1.2 × 1012 ART-I02 vector genomes were administered without systemic side effects or serious AEs. However, local tolerability was insufficient for continuation. TRIAL REGISTRATION: NCT02727764.

Performing a knee arthroscopy among patients with degenerative knee disease: one-third is potentially low value care.

PURPOSE: The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors. METHODS: A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis ("Arthrosis" versus "Meniscal lesion"), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy. RESULTS: Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient-provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984-1.043)], diagnosis [OR 0.998 (95% CI 0.886-1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948-1.032)] were significantly associated with performing a potentially low value knee arthroscopy. CONCLUSIONS: In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care. LEVEL OF EVIDENCE: IV.

Characterization of dynamic changes in Matrix Gla Protein (MGP) gene expression as function of genetic risk alleles, osteoarthritis relevant stimuli, and the vitamin K inhibitor warfarin.

OBJECTIVE: We here aimed to characterize changes of Matrix Gla Protein (MGP) expression in relation to its recently identified OA risk allele rs1800801-T in OA cartilage, subchondral bone and human ex vivo osteochondral explants subjected to OA related stimuli. Given that MGP function depends on vitamin K bioavailability, we studied the effect of frequently prescribed vitamin K antagonist warfarin. METHODS: Differential (allelic) mRNA expression of MGP was analyzed using RNA-sequencing data of human OA cartilage and subchondral bone. Human osteochondral explants were used to study exposures to interleukin one beta (IL-1ß; inflammation), triiodothyronine (T3; Hypertrophy), warfarin, or 65% mechanical stress (65%MS) as function of rs1800801 genotypes. RESULTS: We confirmed that the MGP risk allele rs1800801-T was associated with lower expression and that MGP was significantly upregulated in lesioned as compared to preserved OA tissues, mainly in risk allele carriers, in both cartilage and subchondral bone. Moreover, MGP expression was downregulated in response to OA like triggers in cartilage and subchondral bone and this effect might be reduced in carriers of the rs1800801-T risk allele. Finally, warfarin treatment in cartilage increased COL10A1 and reduced SOX9 and MMP3 expression and in subchondral bone reduced COL1A1 and POSTN expression. DISCUSSION & CONCLUSIONS: Our data highlights that the genetic risk allele lowers MGP expression and upon OA relevant triggers may hamper adequate dynamic changes in MGP expression, mainly in cartilage. The determined direct negative effect of warfarin on human explant cultures functionally underscores the previously found association between vitamin K deficiency and OA.

Are pain, functional limitations and quality of life associated with objectively measured physical activity in patients with end-stage osteoarthritis of the hip or knee?

OBJECTIVES: Physical activity is promoted in patients with hip or knee osteoarthritis (OA), yet little is known about its relationship with symptoms, functional limitations and Quality of Life (QoL). We investigated if OA-associated pain, functional limitations and QoL are associated with objectively measured physical activity in patients with end-stage hip/knee OA. METHODS: Cross-sectional study including patients scheduled for primary total hip/knee arthroplasty. Patients wore an accelerometer (Activ8) with physical activity assessed over waking hours, and expressed as number of activity daily counts (ADC) per hour, %time spent on physical activity i.e. walking, cycling or running (%PA), and %time spent sedentary (%SB). Pain, functional limitations and joint-specific and general QoL were assessed with the Hip disability/Knee Injury and Osteoarthritis Outcome Score (HOOS/KOOS) and the Short Form (SF)-12. Multivariate linear regression models with the three to Z-scores transformed parameters of physical activity as dependent variables and adjusted for confounding, were conducted. RESULTS: 49 hip and 48 knee OA patients were included. In hip and knee OA patients the mean number of ADC, %PA and %SB were 18.79 ± 7.25 and 21.19 ± 6.16, 14 ± 6.4 and 15 ± 5.0, and 66 ± 10.5 and 68 ± 8.7, respectively. In hip OA, better joint-specific and general QoL were associated with more ADC, (ß 0.028; 95%CI:0.007-0.048, ß0.041; 95%CI:0.010-0.071). Also, better general QoL was associated with the %PA (ß 0.040, 95%CI:0.007-0.073). No other associations were found. CONCLUSION: Whereas QoL was associated with physical activity in hip OA, pain and functional limitations were not related to objectively measured physical activity in patients with end-stage hip or knee OA.

Serum fatty acid chain length associates with prevalent symptomatic end-stage osteoarthritis, independent of BMI.

Higher body mass index (BMI) is associated with osteoarthritis (OA) in both weight-bearing and non-weight-bearing joints, suggesting a link between OA and poor metabolic health beyond mechanical loading. This risk may be influenced by systemic factors accompanying BMI. Fluctuations in concentrations of metabolites may mark or even contribute to development of OA. This study explores the association of metabolites with radiographic knee/hip OA prevalence and progression. A 1H-NMR-metabolomics assay was performed on plasma samples of 1564 cases for prevalent OA and 2,125 controls collected from the Rotterdam Study, CHECK, GARP/NORREF and LUMC-arthroplasty cohorts. OA prevalence and 5 to 10 year progression was assessed by means of Kellgren-Lawrence (KL) score and the OARSI-atlas. End-stage knee/hip OA (TJA) was defined as indication for arthroplasty surgery. Controls did not have OA at baseline or follow-up. Principal component analysis of 227 metabolites demonstrated 23 factors, of which 19 remained interpretable after quality-control. Associations of factor scores with OA definitions were investigated with logistic regression. Fatty acids chain length (FALen), which was included in two factors which associated with TJA, was individually associated with both overall OA as well as TJA. Increased Fatty Acid chain Length is associated with OA.

No differences in cost-effectiveness and short-term functional outcomes between cemented and uncemented total knee arthroplasty.

BACKGROUND: There is an ongoing debate regarding optimal fixation of total knee arthroplasty (TKA), however cost has not been addressed as profoundly. Therefore, the current study primarily aimed to compare costs and cost-effectiveness 1 year after cemented or uncemented TKA. A secondary objective was to compare short-term functional outcomes between both groups. METHODS: A posthoc prospective observational multicenter cohort study of 60 cemented and 50 uncemented Low Contact Stress (LCS) knee systems. Outcome was evaluated using the EuroQol5D-3 L (EQ5D) index, in order to calculate quality adjusted life years (QALYs). Total costs were calculated considering direct costs within the hospital setting (inpatient cost) as well as direct and indirect costs outside the hospital. Cost-effectiveness (total costs per QALY), Oxford Knee Score (OKS) and Numeric Rating Scale (NRS) were compared between cemented and uncemented cases at 1 year after surgery. HealthBASKET project, a micro-costing approach, represents the Dutch costs and situation and was used to calculate hospital stay. (In) direct costs outside the healthcare (medical cost and productivity cost) were determined using two validated questionnaires. RESULTS: Median costs per QALY were similar between cemented and uncemented TKA patients (€16,269 and €17,727 respectively; p = 0.50). Median OKS (44 and 42; p = 0.79), EQ5D (0.88 and 0.90; p = 0.82) and NRS for pain (1.0 and 1.0; p = 0.48) and satisfaction (9.0 and 9.0; p = 0.15) were also comparable between both groups. CONCLUSION: For this type of knee implant (LCS), inpatient hospital costs and costs after hospitalization were comparable between groups.

Preferences and beliefs of Dutch orthopaedic surgeons and patients reduce the implementation of "Choosing Wisely" recommendations in degenerative knee disease.

PURPOSE: The purpose of this study was to assess which factors were associated with the implementation of "Choosing Wisely" recommendations to refrain from routine MRI and arthroscopy use in degenerative knee disease. METHODS: Cross-sectional surveys were sent to 123 patients (response rate 95%) and 413 orthopaedic surgeons (response rate 62%) fulfilling the inclusion criteria. Univariate and multivariate logistic regression analyses were used to identify factors associated with implementation of "Choosing Wisely" recommendations. RESULTS: Factors reducing implementation of the MRI recommendation among patients included explanation of added value by an orthopaedic surgeon [OR 0.18 (95% CI 0.07-0.47)] and patient preference for MRI [OR 0.27 (95% CI 0.08-0.92)]. Factors reducing implementation among orthopaedic surgeons were higher valuation of own MRI experience than existing evidence [OR 0.41 (95% CI 0.19-0.88)] and higher estimated patients' knowledge to participate in shared decision-making [OR 0.38 (95% CI 0.17-0.88)]. Factors reducing implementation of the arthroscopy recommendation among patients were orthopaedic surgeons' preferences for an arthroscopy [OR 0.03 (95% CI 0.00-0.22)] and positive experiences with arthroscopy of friends/family [OR 0.03 (95% CI 0.00-0.39)]. Factors reducing implementation among orthopaedic surgeons were higher valuation of own arthroscopy experience than existing evidence [OR 0.17 (95% CI 0.07-0.46)] and belief in the added value [OR 0.28 (95% CI 0.10-0.81)]. CONCLUSIONS: Implementation of "Choosing Wisely" recommendations in degenerative knee disease can be improved by strategies to change clinician beliefs about the added value of MRIs and arthroscopies, and by patient-directed strategies addressing patient preferences and underlying beliefs for added value of MRI and arthroscopies resulting from experiences of people in their environment. LEVEL OF EVIDENCE: IV.

A New Surgical Technique for Internal Shoulder Contractures Secondary to Obstetric Brachial Plexus Injury: An Anterior Coracohumeral Ligament Release.

Background Obstetric brachial plexus injuries result from traction injury during delivery; 30% of these children sustain persisting functional limitations related to an external rotation deficit of the shoulder. The aim of this study was to compare the intraoperative gain in external rotation after a posterior subscapular release and an anterior coracohumeral ligament release. Methods This is a prospective study on 102 children with an internal rotation contracture of the shoulder who received either a posterior subscapular release (posterior skin incision along the medial border of the scapula of 3-5 cm) or an anterior (5-mm skin incision) coracohumeral ligament release between 1996 and 2010. After general anesthesia, internal and external rotations in both adduction and abduction were measured before and after the surgical release. Results After a posterior subscapular release, the intraoperative external rotation improved with a mean of 64 degrees (95% confidence interval [CI]: 54-74; p < 0.001) in adduction and with a mean of 41 degrees (95% CI: 32-49; p < 0.001) in abduction. After an anterior coracohumeral ligament release, external rotation increased with a mean of 61 degrees (95% CI: 56-66; p < 0.001) in adduction and a mean of 42 degrees in abduction (95%CI: 39-45, p < 0.001). Differences between these two groups were not statistically different. Conclusion The anterior release technique shows comparable results with the posterior subscapular release. And since it is performed through a smaller incision of 5 mm, this is our preferred method to increase passive external rotation. Level of evidence II.

A mobile app for postoperative wound care after arthroplasty: Ease of use and perceived usefulness.

BACKGROUND: Early postoperative discharge after joint arthroplasty may lead to decreased wound monitoring. A mobile woundcare app with an integrated algorithm to detect complications may lead to improved monitoring and earlier treatment of complications. In this study, the ease of use and perceived usefulness of such a mobile app was investigated. OBJECTIVE: Primary objective was to investigate the ease of use and perceived usefulness of using a woundcare app. Secondary objectives were the number of alerts created, the amount of days the app was actually used and patient-reported wound infection. METHODS: Patients that received a joint arthroplasty were enrolled in a prospective cohort study. During 30 postoperative days, patients scored their surgical wound by daily answering of questions in the app. An inbuilt algorithm advised patients to contact their treating physician if needed. On day 15 and day 30, additional questionnaires in the app investigated ease of use and perceived usefulness. RESULTS: Sixty-nine patients were included. Median age was 68 years. Forty-one patients (59.4%) used the app until day 30. Mean grade for ease of use (on a Likert-scale of 1-5) were 4.2 on day 15 and 4.2 on day 30; grades for perceived usefulness were 4.1 on day 15 and 4.0 on day 30. Out of 1317 days of app use, an alert was sent to patients on 29 days (2.2%). Concordance between patient-reported outcome and physician-reported outcome was 80%. CONCLUSIONS: Introduction of a woundcare app with an alert communication on possible wound problems resulted in a high perceived usefulness and ease of use. Future studies will focus on validation of the algorithm and the association between postoperative wound leakage and the incidence of prosthetic joint infection.

Metabolic improvement in obese patients after duodenal-jejunal exclusion is associated with intestinal microbiota composition changes.

BACKGROUND: Intestinal microbiota have been suggested to play an important role in the pathogenesis of obesity and type 2 diabetes. Bariatric surgery improves both conditions and has been associated with changes in intestinal microbiota composition. We investigated the effect of a nonsurgical bariatric technique on intestinal microbiota composition in relation to metabolic improvement. METHODS: Seventeen patients with obesity and type 2 diabetes were treated with the nonsurgical duodenal-jejunal bypass liner, which excludes the proximal 60 cm small intestine from food. Fecal samples as well as metabolic parameters reflecting obesity and type 2 diabetes were obtained from the patients at baseline, after 6 months with the device in situ, and 6 months after explantation. RESULTS: After 6 months of treatment, both obesity and type 2 diabetes had improved with a decrease in weight from 106.1 [99.4-123.5] to 97.4 [89.4-114.0] kg and a decrease in HbA1c from 8.5% [7.6-9.2] to 7.2% [6.3-8.1] (both p < 0.05). This was paralleled by an increased abundance of typical small intestinal bacteria such as Proteobacteria, Veillonella, and Lactobacillus spp. in feces. After removal of the duodenal-jejunal bypass liner, fecal microbiota composition was similar to that observed at baseline, despite persistent weight loss. CONCLUSION: Improvement of obesity and type 2 diabetes after exclusion of the proximal 60 cm small intestine by treatment with a nonsurgical duodenal-jejunal bypass liner may be promoted by changes in fecal microbiota composition.

Segmental induction heating of orthopaedic metal implants.

OBJECTIVES: Prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty. Non-contact induction heating of metal implants is a new and emerging treatment for PJI. However, there may be concerns for potential tissue necrosis. It is thought that segmental induction heating can be used to control the thermal dose and to limit collateral thermal injury to the bone and surrounding tissues. The purpose of this study was to determine the thermal dose, for commonly used metal implants in orthopaedic surgery, at various distances from the heating centre (HC). METHODS: Commonly used metal orthopaedic implants (hip stem, intramedullary nail, and locking compression plate (LCP)) were heated segmentally using an induction heater. The thermal dose was expressed in cumulative equivalent minutes at 43°C (CEM43) and measured with a thermal camera at several different distances from the HC. A value of 16 CEM43 was used as the threshold for thermal damage in bone. RESULTS: Despite high thermal doses at the HC (7161 CEM43 to 66 640 CEM43), the thermal dose at various distances from the HC was lower than 16 CEM43 for the hip stem and nail. For the fracture plate without corresponding metal screws, doses higher than 16 CEM43 were measured up to 5 mm from the HC. CONCLUSION: Segmental induction heating concentrates the thermal dose at the targeted metal implant areas and minimizes collateral thermal injury by using the non-heated metal as a heat sink. Implant type and geometry are important factors to consider, as they influence dissipation of heat and associated collateral thermal injury.Cite this article: B. G. Pijls, I. M. J. G. Sanders, E. J. Kuijper, R. G. H. H. Nelissen. Segmental induction heating of orthopaedic metal implants. Bone Joint Res 2018;7:609-619. DOI: 10.1302/2046-3758.711.BJR-2018-0080.R1.