Can Patient-centered Education and Pain Management Delivered by Coaches Improve Pain Outcomes After Orthopaedic Trauma? A Randomized Trial.

BACKGROUND: Pain after orthopaedic trauma is complex, and many patients who have experienced orthopaedic trauma are at increased risk for prolonged opioid utilization after the injury. Patient-centered interventions capable of delivering enhanced education and opioid-sparing pain management approaches must be implemented and evaluated in trauma care settings to improve pain outcomes and minimize opioid-related risks. QUESTIONS/PURPOSES: Does personalized pain education and management delivered by coaches (1) improve pain-related outcomes, (2) reduce opioid consumption, and (3) improve patient-reported outcome measures (Patient-Reported Outcomes Measurement Information System [PROMIS] scores) compared to written discharge instructions on pain management and opioid safety? METHODS: This clinical trial aimed to examine the effect of a personalized pain education and management intervention, delivered by paraprofessional coaches, on pain-related outcomes and opioid consumption compared with usual care (written discharge instructions on pain management and opioid safety). Between February 2021 and September 2022, 212 patients were randomized to the intervention (49% [104]) or control group (51% [108]). A total of 31% (32 of 104) and 47% (51 of 108) in those groups, respectively, were lost before the minimum study follow-up of 12 weeks or had incomplete datasets, leaving 69% (72 of 104) and 53% (57 of 108) for analysis in the intervention and control group, respectively. Patients randomized to the intervention worked with the paraprofessional coaches throughout hospitalization after their orthopaedic injury and at their 2-, 6-, and 12-week visits with the surgical team after discharge to implement mindfulness-based practices and nonpharmacological interventions. Most participants in the final sample of 129 identified as Black (73% [94 of 129]) and women (56% [72 of 129]), the mean Injury Severity score was 8 ± 4, and one-third of participants were at medium to high risk for an opioid-use disorder based on the Opioid Risk Tool. Participants completed surveys during hospitalization and at the 2-, 6-, and 12-week follow-up visits. Surveys included average pain intensity scores over the past 24 hours measured on the pain numeric rating scale from 0 to 10 and PROMIS measures (physical functioning, pain interference, sleep disturbance). Opioid utilization, measured as daily morphine milligram equivalents, was collected from the electronic health record, and demographic and clinical characteristics were collected from self-report surveys. Groups were compared in terms of mean pain scores at at the 12-week follow-up, daily morphine milligram equivalents both during inpatient and at discharge, and mean PROMIS scores at 12 weeks of follow-up. Additionally, differences in the proportion of participants in each group achieving minimum clinically important differences (MCID) on pain and PROMIS scores were examined. For pain scores, an MCID of 2 points on the pain numeric rating scale assessing past 24-hour pain intensity was utilized. RESULTS: We found no difference between the intervention and control in terms of mean pain score at 12 weeks nor in the proportions of patients who achieved the MCID of 2 points for 24-hour average pain scores (85% [61 of 72] versus 72% [41 of 57], respectively, OR 2.2 [95% confidence interval (CI) 0.9 to 5.3]; p = 0.08). No differences were noted in daily morphine milligram equivalents utilized between the intervention and control groups during hospitalization, at discharge, or in prescription refills. Similarly, we observed no differences in the proportions of patients in the intervention and control groups who achieved the MCID on PROMIS Physical Function (81% [58 of 72] versus 63% [36 of 57], respectively, OR 2.2 [95% CI 0.9 to 5.2]; p = 0.06). We saw no differences in the proportions of patients who achieved the MCID on PROMIS Sleep Disturbance between the intervention and control groups (58% [42 of 72] versus 47% [27 of 57], respectively, OR 1.4 [95% CI 0.7 to 3.0]; p = 0.31). The proportion of patients who achieved the MCID on PROMIS Pain Interference scores did not differ between the intervention and the control groups (39% [28 of 72] versus 37% [21 of 57], respectively, OR 1.1 [95% CI 0.5 to 2.1]; p = 0.95). CONCLUSION: In this trial, we observed no differences between the intervention and control groups in terms of pain outcomes, opioid medication utilization, or patient-reported outcomes after orthopaedic trauma. However, future targeted research with diverse samples of patients at increased risk for poor postoperative outcomes is warranted to ascertain a potentially meaningful patient perceived effect on pain outcomes after working with coaches. Other investigators interested in this interventional approach may consider the coach program as a framework at their institutions to increase access to evidence-based nonpharmacological interventions among patients who are at increased risk for poor postoperative pain outcomes. Smaller, more focused programs connecting patients to coaches to learn about nonpharmacological pain management interventions may deliver a larger impact on patient's recovery and outcomes. LEVEL OF EVIDENCE: Level I, therapeutic study.

Gender-specific aspects of socialisation and risk of cardiovascular disease among community-dwelling older adults: a prospective cohort study using machine learning algorithms and a conventional method.

BACKGROUND: Gender influences cardiovascular disease (CVD) through norms, social relations, roles and behaviours. This study identified gender-specific aspects of socialisation associated with CVD. METHODS: A longitudinal study was conducted, involving 9936 (5,231 women and 4705 men) initially healthy, community-dwelling Australians aged 70 years or more from the ASPirin in Reducing Events in the Elderly (ASPREE) study and ASPREE Longitudinal Study of Older Persons, with a median follow-up time of 6.4 years. Variable categorisation, variable selection (using machine learning (ML) models; Elastic Net and extreme gradient boosting) and Cox-regression were employed separately by binary gender to identity socialisation factors (n=25 considered) associated with CVD. RESULTS: Different socialisation factors were identified using the ML models. In the Cox model, for both genders, being married/partnered was associated with a reduced risk of CVD (men: HR 0.76, 95% CI 0.60 to 0.96; women: HR 0.67, 95% CI 0.58 to 0.95). For men, having 3-8 relatives they felt close to and could call on for help (HR 0.76, 95% CI 0.58 to 0.99; reference <3 relatives), having 3-8 relatives they felt at ease talking with about private matters (HR 0.70, 95% CI 0.55 to 0.90; reference <3 relatives) or playing games such as chess or cards (HR 0.82, 95% CI 0.67 to 1.00) was associated with reduced risk of CVD. For women, living with others (HR 0.71, 95% CI 0.55 to 0.91) or having ≥3 friends they felt at ease talking with about private matters (HR 0.74, 95% CI 0.58 to 0.95; reference <3 friends) was associated with a lower risk of CVD. CONCLUSIONS: This study demonstrates the need to prioritise gender-specific social factors to improve cardiovascular health in older adults.

Exploring ex vivo biofilm dynamics: consequences of low ampicillin concentrations on the human oral microbiome.

Prolonged exposure to antibiotics at low concentration can promote processes associated with bacterial biofilm formation, virulence and antibiotic resistance. This can be of high relevance in microbial communities like the oral microbiome, where commensals and pathogens share a common habitat and where the total abundance of antibiotic resistance genes surpasses the abundance in the gut. Here, we used an ex vivo model of human oral biofilms to investigate the impact of ampicillin on biofilm viability. The ecological impact on the microbiome and resistome was investigated using shotgun metagenomics. The results showed that low concentrations promoted significant shifts in microbial taxonomic profile and could enhance biofilm viability by up to 1 to 2-log. For the resistome, low concentrations had no significant impact on antibiotic resistance gene (ARG) diversity, while ARG abundance decreased by up to 84%. A positive correlation was observed between reduced microbial diversity and reduced ARG abundance. The WHO priority pathogens Streptococcus pneumoniae and Staphylococcus aureus were identified in some of the samples, but their abundance was not significantly altered by ampicillin. Most of the antibiotic resistance genes that increased in abundance in the ampicillin group were associated with streptococci, including Streptococcus mitis, a well-known potential donor of ARGs to S. pneumoniae. Overall, the results highlight the potential of using the model to further our understanding of ecological and evolutionary forces driving antimicrobial resistance in oral microbiomes.

Identification of the ilioinguinal and iliohypogastric nerves during open inguinal hernia repair: a nationwide register-based study.

BACKGROUND: Chronic pain remains prevalent after open inguinal hernia repair and nerve-handling strategies are debated. Some guidelines suggest sparing nerves that are encountered; however, the nerve identification rates are unclear. This study aimed to investigate the nerve identification rates in a register-based nationwide cohort. METHODS: This study was reported according to the RECORD guideline and used prospective, routinely collected data from the Danish Hernia Database, which was linked with the National Patient Registry. We included patients ≥ 18 years old, undergoing Lichtenstein hernia repair with information on nerve handling of the iliohypogastric and ilioinguinal nerves. RESULTS: We included 30,911 open hernia repairs performed between 2012 and 2022. The ilioinguinal nerve was identified in 73% of the repairs and the iliohypogastric nerve in 66% of repairs. Both nerves were spared in more than 94% of cases where they were identified. Female patient sex, emergency and recurrence surgery, general anesthesia, medial and saddle hernias, and large defect size all result in lower nerve identification rates for both nerves. CONCLUSION: The Ilioinguinal nerve was recognized in 73% of cases, while the iliohypogastric nerve was recognized in 66% with almost all identified nerves being spared during surgery. Several pre- and intraoperative factors influenced identification rates of the ilioinguinal and iliohypogastric nerve.

Incidence and Risk Factors of Heterotopic Ossification in the Knee After Reamed Tibial Nailing.

INTRODUCTION: Heterotopic ossification (HO) in the knee after tibial intramedullary nailing (IMN) has yet to be thoroughly investigated. Our aim was to assess frequency and associated factors for HO in the knee after tibial IMN. METHODS: This is a retrospective review at a single level 1 urban trauma center of 213 patients who underwent reamed tibial IMN. Plain radiographs were reviewed postoperatively and on final follow-up (≥6 weeks). Chart review was performed for surgical approach (suprapatellar versus infrapatellar), demographics, injury characteristics, and clinical follow-up. The primary outcome was frequency of HO. RESULTS: HO on final follow-up (mean: 41.43 weeks) was recorded in 15% cases. Postsurgical retroinfrapatellar reaming debris (odds ratio [OR], 4.73), Injury Severity Score (OR, 1.05), intensive care unit admission (OR, 2.89), chest injury (OR, 3.4), and ipsilateral retrograde femoral IMN (OR, 5.08) showed a notable association with HO development. No association was observed in HO formation between surgical approach, knee pain, or range-of-motion deficits. DISCUSSION: Radiographic evidence of HO in the knee after reamed tibial IMN is not uncommon and is associated with retained reaming debris, Injury Severity Score, chest injury, intensive care unit admission, and ipsilateral retrograde femoral nailing. No differences were noted in HO formation between approaches. HO was not associated with knee pain or range-of-motion deficits.

Trends in childhood body mass index between 1936 and 2011 showed that underweight remained more common than obesity among 398 970 Danish school children.

AIM: To examine trends in all body mass index (BMI) groups in children from 1936 to 2011. METHODS: We included 197 694 girls and 201 276 boys from the Copenhagen School Health Records Register, born between 1930 and 1996, with longitudinal weight and height measurements (6-14 years). Using International Obesity Task Force criteria, BMI was classified as underweight, normal-weight, overweight and obesity. Sex- and age-specific prevalences were calculated. RESULTS: From the 1930s, the prevalence of underweight was stable until a small increase occurred from 1950 to 1970s, and thereafter it declined into the early 2000s. Using 7-year-olds as an example, underweight changed from 10% to 7% in girls and from 9% to 6% in boys during the study period. The prevalence of overweight plateaued from 1950 to 1970s and then steeply increased from 1970s onwards and in 1990-2000s 15% girls and 11% boys at 7 years had overweight. The prevalence of obesity particularly increased from 1980s onwards and in 1990-2000s 5% girls and 4% boys at 7 years had obesity. These trends slightly differed by age. CONCLUSION: Among Danish schoolchildren, the prevalence of underweight was greater than overweight until the 1980s and greater than obesity throughout the period. Thus, monitoring the prevalence of childhood underweight remains an important public health issue.

'Whether it's your weapon or not, it's your home': US military spouse perspectives on personal firearm storage.

INTRODUCTION: In the USA, an estimated 45% of veterans personally own firearms. Firearm access increases the risk of suicide, so suicide prevention efforts in the US Department of Defense (DoD) focus on lethal means safety, including reducing firearm access. Spouse input may enhance effective messaging and intervention delivery of lethal means safety. This study used qualitative methods to explore the perspectives of military spouses or partners on personal firearm storage, including at-home decisions, on-base storage and existing messaging from the DoD. MATERIALS AND METHODS: Qualitative data were obtained using 1:1 interviews and focus groups with spouses/partners of US military service members (active duty, Reserve, National Guard, recently separated from the military) and representatives from military support organisations. Sessions focused on personal firearm storage (at home or on military installations) and military messaging around secure firearm storage and firearm suicide prevention. Data were analysed using a team-based, mixed deductive-inductive approach. RESULTS: Across 56 participants (August 2022-March 2023), the themes were variability in current home firearm storage and spousal participation in decision-making; uncertainty about firearm storage protocols on military installations; mixed awareness of secure firearm storage messaging from the military; and uncertainty about procedures or protocols for removing firearm access for an at-risk person. CONCLUSION: US military spouses are important messengers for firearm safety and suicide prevention, but they are currently underutilised. Tailored prevention campaigns should consider spousal dynamics and incorporate education about installation procedures.

Epidemiology and surgical management of 184 obturator hernias: a nationwide registry-based cohort study.

PURPOSE: We aimed describe the patient characteristics, surgical details, postoperative outcomes, and prevalence and incidence of obturator hernias. Obturator hernias are rare with high mortality and no consensus on the best surgical approach. Given their rarity, substantial data is lacking, especially related to postoperative outcomes. METHODS: The study was based on data from the nationwide Danish Hernia Database. All adults who underwent obturator hernia surgery in Denmark during 1998-2023 were included. The primary outcomes were demographic characteristics, surgical details, postoperative outcomes, and the prevalence and incidence of obturator hernias. RESULTS: We included 184 obturator hernias in 167 patients (88% females) with a median age of 77 years. Emergency surgeries constituted 42% of repairs, and 72% were laparoscopic. Mesh was used in 77% of the repairs, with sutures exclusively used in emergency repairs. Concurrent groin hernias were found in 57% of cases. Emergency surgeries had a 30-day mortality of 14%, readmission rate of 21%, and median length of stay of 6 days. Elective surgeries had a 30-day mortality of 0%, readmission rate of 10%, and median length of stay of 0 days. The prevalence of obturator hernias in hernia surgery was 0.084% (95% CI: 0.071%-0.098%), with an incidence of one per 400,000 inhabitants annually. CONCLUSIONS: This was the largest cohort study to date on obturator hernias. They were rare, affected primarily elderly women. The method of repair depends on whether the presentation is acute, and emergency repair is associated with higher mortality.

Wilson's disease - a tricky diagnosis on the acute take.

Wilson's disease is a rare genetic disorder that affects copper metabolism in the body, leading to excess copper accumulation in various organs, including the liver and brain. It often presents to both primary and secondary care, with a combination of liver disease and neurological or psychiatric symptoms, but the presentation can be highly variable. Early recognition and treatment of Wilson's disease is important to prevent critical hepatic and neurological complications. In this case report, we describe the presentation of an 18-year-old male university student with a combination of dysphagia, tremors, and slurred speech, which progressed over several months. Through a series of investigations, the patient was diagnosed with Wilson's disease and received appropriate treatment. This report highlights the importance of considering Wilson's disease in patients with a wide range of symptoms and the need for a pragmatic approach to diagnosis, including routine and additional testing as necessary.

Measurement of the N170 during facial neuromuscular electrical stimulation (fNMES).

BACKGROUND: Studies on facial feedback effects typically employ props or posed facial expressions, which often lack temporal precision and muscle specificity. NEW METHOD: Facial Neuromuscular Electrical Stimulation (fNMES) allows for a controlled influence of contractions of facial muscles, and may be used to advance our understanding of facial feedback effects, especially when combined with Electroencephalography (EEG). However, electrical stimulation introduces significant interference that can mask underlying brain dynamics. Whether established signal processing methods can allow for a reduction of said interference whilst retaining effects of interest, remains unexplored. RESULTS: We addressed these questions focusing on the classic N170 visual evoked potential, a face-sensitive brain component: 20 participants viewed images of houses, and of sad, happy, and neutral faces. On half of the trials, fNMES was delivered to bilateral lower-face muscles during the presentation of visual stimuli. A larger N170 amplitude was found for faces relative to houses. Interestingly, this was the case both without and during fNMES, regardless of whether the fNMES artefact was removed or not. Moreover, sad facial expressions elicited a larger N170 amplitude relative to neutral facial expressions, both with and without fNMES. COMPARISON WITH EXISTING METHODS: fNMES offers a more precise way of manipulating proprioceptive feedback from facial muscles, which affords greater diversity in experimental design for studies on facial feedback effects. CONCLUSIONS: We show that the combining of fNMES and EEG can be achieved and may serve as a powerful means of exploring the impact of controlled proprioceptive inputs on various types of cognitive processing.

The relationship between social isolation, social support, and loneliness with cardiovascular disease and shared risk factors: A narrative review.

BACKGROUND: Cardiovascular disease (CVD) is the greatest contributor to global morbidity and mortality. Poor social health plays a critical role in CVD incidence. Additionally, the relationship between social health and CVD may be mediated through CVD risk factors. However, the underlying mechanisms between social health and CVD are poorly understood. Certain social health constructs (social isolation, low social support and loneliness) have complicated the characterisation of a causal relationship between social health and CVD. AIM: To provide an overview of the relationship between social health and CVD (and its shared risk factors). METHOD: In this narrative review, we examined published literature on the relationship between three social health constructs (social isolation, social support, and loneliness) and CVD. Evidence was synthesised in a narrative format, focusing on the potential ways in which social health affects CVD, including shared risk factors. RESULTS: The current literature highlights an established relationship between social health and CVD with a likelihood for bi-directionality. However, there is speculation and varied evidence regarding how these relationships may be mediated through CVD risk factors. CONCLUSIONS: Social health can be considered an established risk factor for CVD. However, the potential bi-directional pathways of social health with CVD risk factors are less established. Further research is needed to understand whether targeting certain constructs of social health may directly improve the management of CVD risk factors. Given the health and economic burdens of poor social health and CVD, improvements to addressing or preventing these interrelated health conditions would have societal benefits.

Tropical deforestation causes large reductions in observed precipitation.

Tropical forests play a critical role in the hydrological cycle and can influence local and regional precipitation1. Previous work has assessed the impacts of tropical deforestation on precipitation, but these efforts have been largely limited to case studies2. A wider analysis of interactions between deforestation and precipitation-and especially how any such interactions might vary across spatial scales-is lacking. Here we show reduced precipitation over deforested regions across the tropics. Our results arise from a pan-tropical assessment of the impacts of 2003-2017 forest loss on precipitation using satellite, station-based and reanalysis datasets. The effect of deforestation on precipitation increased at larger scales, with satellite datasets showing that forest loss caused robust reductions in precipitation at scales greater than 50 km. The greatest declines in precipitation occurred at 200 km, the largest scale we explored, for which 1 percentage point of forest loss reduced precipitation by 0.25 ± 0.1 mm per month. Reanalysis and station-based products disagree on the direction of precipitation responses to forest loss, which we attribute to sparse in situ tropical measurements. We estimate that future deforestation in the Congo will reduce local precipitation by 8-10% in 2100. Our findings provide a compelling argument for tropical forest conservation to support regional climate resilience.

The clinical task force: Improving quality of medical students' internship.

Background: Up to 40% of young medical doctors feel that the internships prepared them insufficiently for the clinical work. This study investigated whether a Clinical Task Force (CTF) could improve internship quality. Methods: The CTF visited internship departments with a triple-targeted approach: first, departments pre-filled a self-evaluating questionnaire; secondly, CTF visited departments to discuss the self-evaluation and previous student evaluations; and thirdly, CTF and departments agreed on several quality-improving focus points to work on after the meeting. Focus points were followed-up after three and 12 months. The impact on internship quality was assessed with departments' student evaluation scores, number of completed focus points, and the effect of completed focus points on a range of learning parameters. The CTF learned several things along the way, that potentially could affect the quality of internships. A shortlist of these was provided to illustrate unmeasurable benefits. Results: The CTF met with 53 out of 60 eligible departments. The CTF and departments agreed upon 197 focus points of which 64% were completed. The three most frequent categories of focus points were Introduction of the students, The departments' evaluation percentage, and The departments' function as an educational site. The mean student evaluation scores did not change significantly, but the individual evaluation parameters changed significantly in two categories. It decreased in the category regarding the students' satisfaction with the clinical lecturers and the scheduled teaching and increased in the category regarding the percentage of students evaluating the department. Conclusion: The CTF's triple-targeted approach did not increase the mean student evaluation score significantly. For departments that completed the agreed focus points, one category increased and another decreased. However, the unmeasurable benefits illustrated that CTF was a good viable linking element between the faculty, departments, and students with the potential of improving other aspects of the quality of internships.

Radiographic Prediction of Soft Tissue Injury Associated with Tibial Plateau Fractures: The Direction of Articular Depression Matters.

This investigation aimed to evaluate the impact of coronal articular fragment displacement of Schatzker type II tibial plateau fractures on concomitant soft tissue knee injuries. One hundred consecutively treated patients were included. Depression depth and coronal articular fragment displacement were measured radiographically, and medial collateral ligament (MCL) and lateral meniscus (LM) injury, and pain and range of motion (ROM) on final follow up, were recorded. Multivariable regression was then performed. Coronal articular fragment displacement was medially and laterally hinged in 74% and 26% of patients, respectively. MCL injuries were significantly higher in the lateral hinge group (odds ratio [OR]: 3.25; confidence interval [CI]: 1.07 to 9.84; p = 0.03). No difference was found in LM injury incidence and amount of articular depression between groups. At final follow-up, average pain and ROM was similar between groups. Findings demonstrate a significant correlation between laterally hinged articular depression in Schatzker II tibial plateau fractures and concomitant MCL injury. (Journal of Surgical Orthopaedic Advances 32(4):270-275, 2023).

Predicting the long-term impact of rotavirus vaccination in 112 countries from 2006 to 2034: A transmission modeling analysis.

Rotavirus vaccination has been shown to reduce rotavirus burden in many countries, but the long-term magnitude of vaccine impacts is unclear, particularly in low-income countries. We use a transmission model to estimate the long-term impact of rotavirus vaccination on deaths and disability adjusted life years (DALYs) from 2006 to 2034 for 112 low- and middle-income countries. We also explore the predicted effectiveness of a one- vs two- dose series and the relative contribution of direct vs indirect effects to overall impacts. To validate the model, we compare predicted percent reductions in severe rotavirus cases with the percent reduction in rotavirus positivity among gastroenteritis hospital admissions for 10 countries with pre- and post-vaccine introduction data. We estimate that vaccination would reduce deaths from rotavirus by 49.1 % (95 % UI: 46.6-54.3 %) by 2034 under realistic coverage scenarios, compared to a scenario without vaccination. Most of this benefit is due to direct benefit to vaccinated individuals (explaining 69-97 % of the overall impact), but indirect protection also appears to enhance impacts. We find that a one-dose schedule would only be about 57 % as effective as a two-dose schedule 12 years after vaccine introduction. Our model closely reproduced observed reductions in rotavirus positivity in the first few years after vaccine introduction in select countries. Rotavirus vaccination is likely to have a substantial impact on rotavirus gastroenteritis and its mortality burden. To sustain this benefit, the complete series of doses is needed.

The role of booster vaccination and ongoing viral evolution in seasonal circulation of SARS-CoV-2.

Periodic resurgences of COVID-19 in the coming years can be expected, while public health interventions may be able to reduce their intensity. We used a transmission model to assess how the use of booster doses and non-pharmaceutical interventions (NPIs) amid ongoing pathogen evolution might influence future transmission waves. We find that incidence is likely to increase as NPIs relax, with a second seasonally driven surge expected in autumn 2022. However, booster doses can greatly reduce the intensity of both waves and reduce cumulative deaths by 20% between 7 January 2022 and 7 January 2023. Reintroducing NPIs during the autumn as incidence begins to increase again could also be impactful. Combining boosters and NPIs results in a 30% decrease in cumulative deaths, with potential for greater impacts if variant-adapted boosters are used. Reintroducing these NPIs in autumn 2022 as transmission rates increase provides similar benefits to sustaining NPIs indefinitely (307 000 deaths with indefinite NPIs and boosters compared with 304 000 deaths with transient NPIs and boosters). If novel variants with increased transmissibility or immune escape emerge, deaths will be higher, but vaccination and NPIs are expected to remain effective tools to decrease both cumulative and peak health system burden, providing proportionally similar relative impacts.

[18F]Sodium fluoride PET-MRI detects increased metabolic bone response to whole-joint loading stress in osteoarthritic knees.

OBJECTIVE: Altered joint function is a hallmark of osteoarthritis (OA). Imaging techniques for joint function are limited, but [18F]sodium fluoride (NaF) PET-MRI may assess the acute joint response to loading stresses. [18F]NaF PET-MRI was used to study the acute joint response to exercise in OA knees, and compare relationships between regions of increased uptake after loading and structural OA progression two years later. METHODS: In this prospective study, 10 participants with knee OA (59 ± 8 years; 8 female) were scanned twice consecutively using a PET-MR system and performed a one-legged squat exercise between scans. Changes in tracer uptake measures in 9 bone regions were compared between knees that did and did not exercise with a mixed-effects model. Areas of focally large changes in uptake between scans (ROIfocal, ΔSUVmax > 3) were identified and the presence of structural MRI features was noted. Five participants returned two years later to assess structural change on MRI. RESULTS: There was a significant increase in [18F]NaF uptake in OA exercised knees (SUV P < 0.001, KiP = 0.002, K1P < 0.001) that differed by bone region. CONCLUSION: There were regional differences in the acute bone metabolic response to exercise and areas of focally large changes in the metabolic bone response that might be representative of whole-joint dysfunction.