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OBJECTIVES: Adipose tissue has been associated with knee osteoarthritis (KOA) pathogenesis, but the longitudinal changes in adipose tissue with KOA progression have not been carefully evaluated. This study aimed to determine if longitudinal changes of systemic and local adipose tissue is associated with radiographic progression of KOA. METHODS: This case-control study used data from the Osteoarthritis Initiative (OAI) and included 315 cases (all the right knees with a minimum of Kellgren-Lawrence score (KL) of 0 and an increase of ≥ 1 KL from baseline to 48 months) and 315 controls matched by age, sex, race, and baseline KL. Cross sectional area of IPFP (IPFP CSA) and subcutaneous adipose tissue around the distal thigh (SCATthigh) were measured using MRI images at baseline and 24 months. Conditional logistic regression models were fitted to estimate associations of obesity markers, IPFP CSA, and SCATthigh with radiographic KOA progression. Mediation analysis was used to assess whether IPFP CSA or SCATthigh mediates the relationships between baseline BMI and radiographic KOA progression. RESULTS: 24-month changes of IPFP CSA (ΔIPFP CSA) and SCATthigh (ΔSCATthigh) were significantly greater in cases compared to controls, whereas Δ BMI and Δ abdominal circumference were similar in both groups during follow-up. Adjusted ORs for radiographic KOA progression were 9.299, 95% CI (5.357-16.141) per 1 SD increase of Δ IPFP CSA and 1.646, 95% CI (1.288-2.103) per 1 SD increase of Δ SCATthigh. ΔIPFP CSA mediated the association between baseline BMI and radiographic KOA progression (87%). CONCLUSIONS: Subjects with radiographic progression of KOA, had significant increases in IPFP CSA and subcutaneous adipose tissue while BMI and abdominal circumference remained stable. Additional studies are needed to confirm these associations.

BACKGROUND: The polyarticular nature of Osteoarthritis (OA) tends to manifest in multi-joints. Associations between cartilage health in connected joints can help identify early degeneration and offer the potential for biomechanical intervention. Such associations between hip and knee cartilages remain understudied. PURPOSE: To investigate T1p associations between hip-femoral and acetabular-cartilage subregions with Intra-limb and Inter-limb patellar cartilage; whole and deep-medial (DM), deep-lateral (DL), superficial-medial (SM), superficial-lateral (SL) subregions. STUDY TYPE: Prospective. SUBJECTS: Twenty-eight subjects (age 55.1 ± 12.8 years, 15 females) with none-to-moderate hip-OA while no radiographic knee-OA. FIELD STRENGTH/SEQUENCE: 3-T, bilateral hip, and knee: 3D-proton-density-fat-saturated (PDFS) Cube and Magnetization-Prepared-Angle-Modulated-Partitioned-k-Space-Spoiled-Gradient-Echo-Snapshots (MAPSS). ASSESSMENT: Ages of subjects were categorized into Group-1 (≤40), Group-2 (41-50), Group-3 (51-60), Group-4 (61-70), Group-5 (71-80), and Group-6 (≥81). Hip T1p maps, co-registered to Cube, underwent an atlas-based algorithm to quantify femoral and acetabular subregional (R2-R7) cartilage T1p. For knee Cube, a combination of V-Net architectures was used to segment the patellar cartilage and subregions (DM, DL, SM, SL). T1p values were computed from co-registered MAPSS. STATISTICAL TESTS: For Intra-and-Inter-limb, 5 optimum predictors out of 13 (Hip subregional T1p, age group, gender) were selected by univariate linear-regression, to predict outcome (patellar T1p). The top five predictors were stepwise added to six linear mixed-effect (LME) models. In all LME models, we assume the data come from the same subject sharing the same random effect. The best-performing models (LME-modelbest) selected via ANOVA, were tested with DM, SM, SL, and DL subregional-mean T1p. LME assumptions were verified (normality of residuals, random-effects, and posterior-predictive-checks). RESULTS: LME-modelbest (Intra-limb) had significant negative and positive fixed-effects of femoral-R5 and acetabular-R2 T1p, respectively (conditional-R2 = 0.581). LME-modelbest (Inter-limb) had significant positive fixed-effects of femoral-R3 T1p (conditional-R2 = 0.26). DATA CONCLUSION: Significant positive and negative T1p associations were identified between load-bearing hip cartilage-subregions vs. ipsilateral and contralateral patellar cartilages respectively. The effects were localized on medial subregions of Inter-limb, in particular. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Excessive growth hormone (GH) has been shown to promote joint degeneration in both preclinical and clinical studies. Little is known about the effect of disrupted GH or GH receptor (GHR) on joint health. The goal of this study is to investigate joint pathology in mice with either germline (GHR-/-) or adult inducible (iGHR-/-) GHR deficiency. Knee joints from male and female GHR-/- and WT mice at 24 months of age were processed for histological analysis. Also, knee joints from male and female iGHR-/- and WT mice at 22 months of age were scanned by micro-CT (μCT) for subchondral bone changes and characterized via histology for cartilage degeneration. Joint sections were also stained for the chondrocyte hypertrophy marker, COLX, and the cartilage degeneration marker, ADAMTS-5, using immunohistochemistry. Compared to WT mice, GHR-/- mice had remarkably smooth articular joint surfaces and an even distribution of proteoglycan with no signs of degeneration. Quantitatively, GHR-/- mice had lower OARSI and Mankin scores compared to WT controls. By contrast, iGHR-/- mice were only moderately protected from developing aging-associated OA. iGHR-/- mice had a significantly lower Mankin score compared to WT. However, Mankin scores were not significantly different between iGHR-/- and WT when males and females were analyzed separately. OARSI scores did not differ significantly between WT and iGHR-/- in either individual or combined sex analyses. Both GHR-/- and iGHR-/- mice had fewer COLX+ hypertrophic chondrocytes compared to WT, while no significant difference was observed in ADAMTS-5 staining. Compared to WT, a significantly lower trabecular thickness in the subchondral bone was observed in the iGHR-/- male mice but not in the female mice. However, there were no significant differences between WT and iGHR-/- mice in the bone volume to total tissue volume (BV/TV), bone mineral density (BMD), and trabecular number in either sex. This study identified that both germline and adult-induced GHR deficiency protected mice from developing aging-associated OA with more effective protection in GHR-/- mice.

INTRODUCTION: The incidence of periprosthetic distal femur fractures (PDFF) is increasing as the number of total knee replacements becomes more common. This study compared the demographics, fracture characteristics, treatment, and outcomes of periprosthetic versus native distal femur fractures (NDFF). MATERIALS AND METHODS: This was a retrospective cohort study of patients ≥ 18 who underwent surgical fixation of NDFF or PDFF from 2012 to 2020 at a level-1 trauma center. The main variables collected included demographics, AO/OTA fracture classification, fixation construct, concomitant fractures, polytrauma rates, bone density, and reduction quality. Primary outcomes were unexpected return to the operating room (UROR), hospital length of stay, and quality of reduction. T-tests, Fishers exact tests, and multivariate analyses were used for statistical analysis. RESULTS: 209 patients were identified, including 70 PDFF and 139 NDFF. PDFF patients were elderly females (81%) with isolated (80%) and comminuted (85%) 33 A.3 (71%) fractures. NDFF patients included 53% females, were commonly middle-aged, and displayed comminuted (92%) 33 C.2 fractures. 48% of NDFF patients had concomitant fractures. Intramedullary nailing was the primary fixation for both groups, followed by nail-plate combination (37%) for PDFF and lateral locking plates (21%) for NDFF. NDFF patients experienced significantly longer hospital stays, higher UROR rates, and worse quality of reduction (p

PURPOSE: Advancing age is one of the strongest risk factors for osteoarthritis (OA). DNA methylation-based measures of epigenetic age acceleration may provide insights into mechanisms underlying OA. METHODS: We analyzed data from the Multicenter Osteoarthritis Study in a subset of 671 participants ages 45-69 years with no or mild radiographic knee OA. DNA methylation was assessed with the Illumina Infinium MethylationEPIC 850K array. We calculated predicted epigenetic age according to Hannum, Horvath, PhenoAge, and GrimAge epigenetic clocks, then regressed epigenetic age on chronological age to obtain the residuals. Associations between the residuals and knee, hand, and multi-joint OA were assessed using logistic regression, adjusted for chronological age, sex, clinical site, smoking status, and race. RESULTS: Twenty-three percent met criteria for radiographic hand OA, 25% met criteria for radiographic knee OA, and 8% met criteria for multi-joint OA. Mean chronological age (SD) was 58.4 (6.7) years. Mean predicted epigenetic age (SD) according to Horvath, Hannum, PhenoAge, and GrimAge epigenetic clocks was 64.9 (6.4), 68.6 (5.9), 50.5 (7.7), and 67.0 (6.2), respectively. Horvath epigenetic age acceleration was not associated with an increased odds of hand OA, odds ratio (95% confidence intervals) = 1.03 (0.99-1.08), with similar findings for knee and multi-joint OA. We found similar magnitudes of associations for Hannum epigenetic age, PhenoAge, and GrimAge acceleration compared to Horvath epigenetic age acceleration. CONCLUSIONS: Epigenetic age acceleration as measured by various well-validated epigenetic clocks based on DNA methylation was not associated with increased risk of knee, hand, or multi-joint OA independent of chronological age.

PURPOSE: Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. PARTICIPANTS: World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. FINDINGS TO DATE: World COACH currently consists of 9 cohorts, with 38 021 participants aged 18-80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8-12 years of follow-up. Even longer radiographic follow-up (15-25 years) is available for over 6000 of these participants. FUTURE PLANS: The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.

ObjectiveCartilage degeneration involves structural, compositional, and biomechanical alterations that may be detected non-invasively using quantitative MRI. The goal of this study was to determine if topographical variation in T1rho values correlates with indentation stiffness and biochemical contents of human patellar cartilage.DesignCadaveric patellae from unilateral knees of 5 donors with moderate degeneration were imaged at 3-Telsa with spiral chopped magnetization preparation T1rho sequence. Indentation testing was performed, followed by biochemical analyses to determine water and sulfated glycosaminoglycan contents. T1rho values were compared to indentation stiffness, using semi-circular regions of interest (ROIs) of varying sizes at each indentation site. ROIs matching the resected tissues were analyzed, and univariate and multivariate regression analyses were performed to compare T1rho values to biochemical contents.ResultsGrossly, superficial degenerative change of the cartilage (i.e., roughened texture and erosion) corresponded with regions of high T1rho values. High T1rho values correlated with low indentation stiffness, and the strength of correlation varied slightly with the ROI size. Spatial variations in T1rho values correlated positively with that of the water content (R2 = 0.10, p

OBJECTIVE: To determine i) pain phenotypes (PP) in people with early-stage knee osteoarthritis (EKOA); ii) the longitudinal association between the phenotypes and pain worsening at two years. DESIGN: We studied participants with EKOA from the Multicenter Osteoarthritis Study defined as pain intensity ≤3/10, Kellgren and Lawrence grade ≤2, intermittent pain none to sometimes, and no constant pain. Two models of PP were explored. Model A included pressure pain thresholds, temporal summation, conditioned pain modulation, pain catastrophizing, sleep quality, depression, and widespread pain (WSP). In Model B, gait characteristics, quadriceps strength, comorbidities, and magnetic resonance imaging features were added to Model A. Latent Class Analysis was used to create phenotypes, and logistic regression was used to determine their association with pain worsening. RESULTS: 750 individuals (60% females), mean age [standard deviation (SD)]: 60.3 (9.4) were included in Model A and 333 individuals (60% females), mean age (SD): 59.4 (8.1) in Model B. 3-class and 4-class solutions were chosen for Model A and Model B. In Model A, the most severe phenotype was dominated by psychosocial factors, WSP, and measures of nervous system sensitization. Similarly in Model B, the Model A phenotype plus gait variables, quadriceps strength, and comorbidities were dominant. Surprisingly, none of the phenotypes in either model had a significant relationship with pain worsening. CONCLUSION: Phenotypes based upon various factors thought to be important for the pain experience were identified in those with EKOA but were not significantly related to pain worsening. These phenotypes require validation with clinically relevant endpoints.

BackgroundObesity influences the development of osteoarthritis via low-grade inflammation. Progression of local inflammation (= synovitis) increased with weight gain in overweight and obese women compared to stable weight. Synovitis could be associated with subcutaneous fat (SCF) around the knee. Purpose of the study was to investigate the effect of weight loss on synovitis progression and to assess whether SCF around the knee mediates the relationship between weight loss and synovitis progression.MethodsWe included 234 overweight and obese participants (body mass index [BMI] ≥ 25 kg/m2) from the Osteoarthritis Initiative (OAI) with > 10% weight loss (n = 117) or stable overweight (

Aims Methods Results Conclusions In many countries, pain is the most common indication for use of antidepressants in older adults. We reviewed the evidence from randomized controlled trials on the efficacy and safety of antidepressants, compared to all alternatives for pain in older adults (aged ≥65 years).Trials published from inception to 1 February 2024, were retrieved from 13 databases. Two independent reviewers extracted data on study and participant characteristics, primary efficacy (pain scores, converted to 0–100 scale) and harms. Estimates for efficacy were pooled using a random effects model and reported as difference in means and 95% CI. Quality of included trials was assessed using the Cochrane risk of bias tool.Fifteen studies (n = 1369 participants) met the inclusion criteria. The most frequently studied antidepressants were duloxetine and amitriptyline (6/15 studies each). Pain related to knee osteoarthritis was the most studied (6/15 studies). For knee osteoarthritis, antidepressants did not provide a statistically significant effect for the immediate term (0–2 weeks), (−5.6, 95% confidence interval [CI]: −11.5 to 0.3), but duloxetine provided a statistically significant, albeit a very small effect in the intermediate term, (≥6 weeks and <12 months), (−9.1, 95% CI: −11.8 to −6.4). Almost half (7/15) of the studies reported increased withdrawal of participants in the antidepressant treatment group vs. the comparator group due to adverse events.For most chronic painful conditions, the benefits and harms of antidepressant medicines are unclear. This evidence is predominantly from trials with sample sizes of <100, have disclosed industry ties and classified as having unclear or high risk of bias. [ABSTRACT FROM AUTHOR]

Introduction: Total knee arthroplasty (TKA) is accompanied by severe postoperative pain, which is reported to be an important cause of chronic pain. Ultrasound-guided adductor canal block (ACB) combined with infiltration between the popliteal artery and posterior capsular of the knee (IPACK) has been proven to have a better effect on relieving acute pain after TKA. However, whether it has a significant effect on the incidence of chronic pain after TKA has not been reported. This trial was designed to investigate the effect of ultrasound-guided ACB combined with IPACK on the incidence and intensity of chronic pain after TKA. Methods: In this prospective, randomized, double-blind, placebo-controlled study, 100 subjects scheduled for TKA were randomly (1:1) divided into two groups: the ropivacaine group and the placebo group. Patients in each group received ultrasound-guided ACB + IPACK procedures with 0.25% ropivacaine or equal volume normal saline. All patients received multimodal analgesia. Pain intensity was assessed using the Numerical Rating Scale (NRS). The primary outcome was the incidence of chronic pain at 3 months after TKA by telephone follow-up. In addition, pain intensity in early resting and mobilized states, chronic pain intensity, the time to first rescue analgesia; opioid consumption; CRP and IL-6 after the operation; length of postoperative hospital stay; and cost of hospitalization and postoperative complications; as well as the function of the knee in the early stage after the operation, were recorded. Results: Ninety-one participants were included in the final analysis. At 3 months, the incidence of chronic pain was 30.4% in the ropivacaine group, significantly lower than 51.1% in the placebo group. Compared with the placebo group, the ACB + IPACK with ropivacaine group had significantly lower pain scores at 4 hours, 8 hours, 16 hours, and 24 hours after the operation; increased the knee range of motion at 8 hours and 24 hours after the operation; and a significantly decreased incidence of chronic pain at 3 months after the operation. During the follow-up period, there were no nerve block-related complications in either group. Conclusion: In the context of multimodal analgesia protocols, ACB combined with IPACK before surgery decreases the incidence and intensity of chronic pain 3 months after TKA compared with placebo injection. In addition, it reduces the NRS scores, whether at rest or during mobilization, and improves knee function within 24 hours after TKA. Trial registration: This trial was registered in the China Clinical Trial Center (registration number ChiCTR2200065300) on November 1, 2022. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess radiolucent lines (RLLs) and to determine their effect on clinical outcomes of the newly introduced cementless mobile-bearing total knee arthroplasty (TKA) system. This was prospective, multicentre study. Seventy-eight patients with knee osteoarthritis who underwent primary TKA were enrolled. Patient-reported outcome measures (PROMs) and radiographic assessments were evaluated at preoperative baseline and at 6 weeks, 1 year, and 2 years after surgery. KOOS, PKIP, 2011KSS, EQ-5D-3L and SKO improved from preoperative baseline to all postoperative timepoints, with no loosening of components. No RLLs were detected at 6 weeks after surgery. However, RLLs ≥ 1 mm developed in 2.8% of the patients for the femur and 9.7% for the tibia at 1 year after surgery, and values were 5.7% and 10.9%, respectively, at 2 years after surgery. RLL incidence was not correlated with PROMs. Age, sex, body mass index, range of motion knee flexion, posterior cruciate ligament treatment and β angle did not impact the occurrence of RLLs. There were no intraoperative complications, revisions or reoperations. This TKA system improved PROMs and showed less incidence of RLLs compared to the previous reported TKA without implant-related complications. [ABSTRACT FROM AUTHOR]

In a randomized, controlled study, whole-body electromyostimulation (WB-EMS) was investigated as a promising alternative treatment technique compared to conventional strength training for the management of knee osteoarthritis (OA). Seventy-two overweight participants with symptomatic knee OA were randomly assigned to WB-EMS (n = 36) or a usual care group (UCG, n = 36). For seven months, the WB-EMS group received three times per fortnight a WB-EMS training, while the UCG was prescribed six-times physiotherapeutic treatments. We observed significant effects for the primary outcome "pain", as determined by the Knee injury and Osteoarthritis Outcome Score (KOOS), with more favourable changes in the WB-EMS group vs UCG (between-group difference 9.0 points, 95%CI 2.9–15.1, p = 0.004). Secondary outcomes, including the other KOOS subscales (symptoms, function in daily living, function in sports/recreational activities and quality of life), 7 day pain diary, hip/leg extensor strength and lower limb function (30s sit-to-stand test), were also statistically significant in favour of the WB-EMS group. Overall, WB-EMS was found to be effective in relieving knee pain symptoms and improving physical function in individuals with symptomatic knee OA compared to usual care treatment. WB-EMS could be used as an alternative therapy in the management of knee OA; particularly for patients that cannot be motivated for conventional training. [ABSTRACT FROM AUTHOR]

Background: Studies comparing the effectiveness of arthroscopic knee surgery and conservative treatment on knee osteoarthritis (OA) came up with inconsistent results. Systematic review on this topic still is still lacking. This systematic review and meta-analysis aimed to evaluate the effectiveness of arthroscopic knee surgery on knee OA, compared to conservative treatments. Materials and methods: Literature searches were performed in PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) published before on 1st July 2024. Studies comparing the effectiveness of arthroscopy and conservative treatments only on knee OA were included. Quality of included studies was evaluated by risk of bias 2 (ROB2). Long-term results in terms of pain relief, functional recovery and patients reported satisfaction were meta-analyzed to evaluate the therapeutic effectiveness. Results: Ten studies were included in this review, among which only 1 was considered as low risk of bias. Five studies were involved in meta-analyses and no difference was found in therapeutic effectiveness of arthroscopic surgery and conservative treatment on knee OA, in the evaluation of VAS (p = 0.63), WOMAC (p = 0.38), SF-36 (p = 0.74) and patient satisfaction (p = 0.07). Conclusion: The evidence does not support the effectiveness of arthroscopic knee surgery compared to conservative treatments in knee OA. [ABSTRACT FROM AUTHOR]

This case study aims to examine changes in the lower limb joint kinematic profile and performance stability induced by repeated ski runs in two world‐class alpine skiers. Two Olympic medallist alpine skiers were tested during their slalom training, with continuous recording of right knee and hip angles, along with turn time and run time. The eight runs of the training session were analysed with linear mixed models. Results showed no effect of runs repetition on performance (i.e., run and turn time; P ≥ 0.279). There was no global effect of runs repetition on minimal and maximal angles for either the knee or the hip (P > 0.151). There was an interaction between run and leg for the maximal angle of both the knee and hip (P ≤ 0.047), which increased across runs for the outside leg and decreased for the inside leg. The maximal angular velocity for both the knee and hip increased with runs repetition in extension (P ≤ 0.028). There were no overall changes in maximal angular velocity in flexion with runs repetition (P ≥ 0.264), but there was an interaction between run and leg for the knee (P < 0.001) due to faster eccentric velocities across runs for the outside leg and slower velocities for the inside leg. In conclusion, the observed joint kinematic alterations without concomitant performance impairment support the concept of multiple movement strategies in athletes to achieve similar performance, especially under fatigue conditions. [ABSTRACT FROM AUTHOR]

Stiff knee gait (SKG) occurrence after a stroke is associated with various abnormal muscle activities; however, the interactions among these muscles are unclear. This study aimed to elucidate the muscle synergy characteristics during walking in patients with SKG after a stroke. This cross-sectional study included 20 patients with poststroke SKG (SKG group), 16 patients without poststroke SKG (non-SKG group), and 15 healthy adults (control group). Participants walked a 10-m distance at a comfortable speed, and electromyographic data were recorded from six lower-limb muscles. Non-negative matrix factorization was employed to derive time-varying activity (C), muscle weights (W), and the percentage of total variance accounted for (tVAF) for muscle synergies. The SKG group showed a higher tVAF than the control group. The initial stance module (including knee extensors) showed increased activity during the swing phase. The initial swing module (including hip flexors and ankle dorsiflexors) exhibited a higher activity during the single-support phase but a lower activity during the swing phase. The synergy structure in patients with SKG after stroke was simplified, with specific abnormalities in synergy activities. SKG may arise from several synergy alterations involving multiple muscles, indicating that approaches focused on controlling individual muscle activities are unsuitable. [ABSTRACT FROM AUTHOR]

Recent years have witnessed breakthroughs in assistive exoskeletons; both passive and active devices have reduced metabolic costs near preferred walking speed by assisting muscle actions. Metabolic reductions at multiple speeds should thus also be attainable. Musculoskeletal simulation can potentially predict the interaction between assistive moments, muscle-tendon mechanics, and walking energetics. In this study, we simulated devices' optimal assistive moments based on minimal muscle activations during walking with prescribed kinematics and dynamics. We used a generic musculoskeletal model with tuned muscle-tendon parameters and computed metabolic rates from muscle actions. We then simulated walking across multiple speeds and with two ideal actuation modes–motor-based and spring-based–to assist ankle plantarflexion, knee extension, hip flexion, and hip abduction and compared computed metabolic rates. We found that both actuation modes considerably reduced physiological joint moments but did not always reduce metabolic rates. Compared to unassisted conditions, motor-based ankle plantarflexion and hip flexion assistance reduced metabolic rates, and this effect was more pronounced as walking speed increased. Spring-based hip flexion and abduction assistance increased metabolic rates at some walking speeds despite a moderate decrease in some muscle activations. Both modes of knee extension assistance reduced metabolic rates to a small extent, even though the actuation contributed with practically the entire net knee extension moment during stance. Motor-based hip abduction assistance reduced metabolic rates more than spring-based assistance, though this reduction was relatively small. Our study also suggests that an assistive strategy based on minimal muscle activations might result in a suboptimal reduction of metabolic rates. Future work should experimentally validate the effects of assistive moments and refine modeling assumptions accordingly. Our computational workflow is freely available online. Author summary: We used simulation to identify ideal assistance at major lower limb joints that can potentially be produced by motor-based or spring-based assistive devices in slow, normal, and fast walking. We found that assistance from both actuation modes decreased muscle activations and net muscle moments to varying extents, depending on joint and walking speed, but they did not always reduce metabolic energy of muscles. Motor-based assistance was overall more effective than spring-based assistance, and spring-based assistance at times increased the metabolic energy. The largest metabolic energy reductions occurred with motor-based plantarflexion assistance, followed by motor-based hip flexion assistance, both more notably at higher speeds. Motor-based hip abduction assistance also reduced metabolic energy, somewhat inversely with walking speed. Spring-based assistance was overall less effective than motor-based assistance but did reduce metabolic energy with plantarflexion assistance in slow walking and with hip flexion assistance in fast walking. Knee extension assistance, regardless of actuation mode or walking speed, had little to no influence on metabolic energy. Our simulation findings do not support knee extension assistance at all, nor spring-based hip flexion assistance in slow walking or hip abduction assistance at any speed if a device goal is to reduce muscle activations. [ABSTRACT FROM AUTHOR]

Background: The growth of arthroplasty procedures requires innovative strategies to reduce inpatients' hospital length of stay (LOS). This study aims to develop a machine learning prediction model that may aid in predicting LOS after hip or knee arthroplasties. Methods: A collection of all the clinical notes of patients who underwent elective primary or revision arthroplasty from 1 January 2019 to 31 December 2019 was performed. The hospitalization was classified as "short LOS" if it was less than or equal to 6 days and "long LOS" if it was greater than 7 days. Clinical data from pre-operative laboratory analysis, vital parameters, and demographic characteristics of patients were screened. Final data were used to train a logistic regression model with the aim of predicting short or long LOS. Results: The final dataset was composed of 1517 patients (795 "long LOS", 722 "short LOS", p = 0.3196) with a total of 1541 hospital admissions (729 "long LOS", 812 "short LOS", p < 0.001). The complete model had a prediction efficacy of 78.99% (AUC 0.7899). Conclusions: Machine learning may facilitate day-by-day clinical practice determination of which patients are suitable for a shorter LOS and which for a longer LOS, in which a cautious approach could be recommended. [ABSTRACT FROM AUTHOR]

Objective: The relationship between spontaneous osteonecrosis of the knee (SONK) and ipsilateral meniscus tear remains to be established, and the possible causes are clarified and summarized. Methods: We conducted a search in Pubmed, Web of Science, Embase, and the Cochrane Library to include all English articles published from the establishment of the database until April 2023. The odds ratio (OR) and 95% confidence interval (CI) were calculated to evaluate the relationship between SONK and ipsilateral meniscus lesions. Results: A total of 405 patients were included in eight articles, including 157 males and 248 females, with an average age of 63.94 years and an average BMI of 26.36 kg/m2. In patients with medial SONK, the prevalence of ipsilateral meniscus tear was 0.8982, 95% CI (0.7389, 0.9648), and the prevalence of ipsilateral posterior root tear was 0.6198, 95% CI (0.5169, 0.7118). The prevalence of ipsilateral meniscus tears in patients with lateral SONK was 0.2188, 95% CI (0.1150, 0.3711), and the prevalence of ipsilateral posterior root tears was 0.1667, 95% CI (0.1071, 0.2424). Conclusions: SONK is significantly associated with meniscus or root tears, which limit meniscus function and lead to changes in the stress environment between the knee and the tibiofemur, increasing the chance of incomplete fracture. We suggest that the expression of SONK can be replaced with subchondral insufficiency fracture of the knee. [ABSTRACT FROM AUTHOR]

The present study aimed to determine the optimal posterior tibial plateau inclination for fixed-platform unicondylar knee arthroplasty (UKA) using finite element analysis (FEA). These findings provided a theoretical basis for selecting an appropriate posterior inclination of the tibial plateau during surgery. The present study utilized the FEA method to create models of fixed-platform UKA with tibial plateau posterior inclinations of 3, 6 and 9˚. The stress changes in the internal structures of each model after knee flexion motion were then compared. During knee flexion from 0 to 90˚, the contact and Von Mises equivalent stresses of the femoral condyle prosthesis and tibial platform pad revealed consistent trends of 3˚ posterior inclination, >6˚ posterior inclination and >9˚ posterior inclination. The present study established the first quasi-dynamic fixed-platform UKA model of the knee joint under load-bearing conditions. From a theoretical perspective, it was found that controlling the posterior inclination of UKA between 6 and 9˚ may be more beneficial for the survival of the tibial platform pad than between 3 and 6˚. It is also more effective in reducing pad wear. [ABSTRACT FROM AUTHOR]

Background Sidestep cutting technique is highly individual and has been shown to influence knee joint loading. However, studies assessing whether individualized technique feedback improves technique and ACL injury-relevant knee joint loads instantly in a sport-specific task are lacking. Purpose To determine the instant effects of individualized augmented technique feedback and instructions on technique and the peak external knee abduction moment (pKAM) in a handball-specific sidestep cut. Additionally, to determine the effects of technique modifications on the resultant ground reaction force and its frontal plane moment arm to the knee joint center. Study Design Controlled laboratory cohort study Methods Three-dimensional biomechanics of 48 adolescent female handball players were recorded during a handball-specific sidestep cut. Following baseline cuts to each side, leg-specific visual and verbal technique feedback on foot strike angle, knee valgus motion, or vertical impact velocity using a hierarchically organized structure accounting for the variables' association with performance was provided. Subsequently, sidestep cuts were performed again while verbal instructions were provided to guide technique modifications. Combined effects of feedback and instructions on technique and pKAM as well as on the resultant ground reaction force and its frontal plane moment arm to the knee joint center were assessed. Results On average, each targeted technique variable improved following feedback and instructions, leading to instant reductions in pKAM of 13.4% to 17.1%. High inter-individual differences in response to feedback-instruction combinations were observed. These differences were evident in both the adherence to instructions and the impact on pKAM and its components. Conclusion Most players were able to instantly adapt their technique and decrease ACL injury-relevant knee joint loads through individualized augmented technique feedback, thereby potentially reducing the risk of injury. More research is needed to assess the retention of these adaptations and move towards on-field technique assessments using low-cost equipment. Level of Evidence: Level 3 [ABSTRACT FROM AUTHOR]

Objectives: This study aims to compare the effectiveness of intra-articular and peri-articular dextrose prolotherapy (DPT) in patients with knee osteoarthritis (KOA) without effusion. Patients and methods: Between August 2018 and November 2018, a total of 51 participants including 27 cases (12 males, 15 females; mean age: 55.7±5.2 years; range, 38 to 70 years) in Group A and 24 cases (9 males, 15 females; mean age: 54.7±4.6 years; range, 38 to 70 years) in Group B were recruited. Group A received intra-articular DPT, while Group B received peri-articular DPT. Treatment was administered two times with two-week intervals. The Visual Analog Scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Oxford Knee Scale (OKS) questionnaires were filled at baseline, and four and eight weeks after first injection. Results: At four and eight weeks, the VAS, OKS, and WOMAC scores improved from baseline in both groups. There was no significant difference in the WOMAC and OKS scores between two methods. The VAS scores showed superiority of intra-articular method (p<0.05). Conclusion: Both peri-articular and intra-articular DPT were effective in patients with KOA. There was no superiority in terms of functional improvement between two groups. However, intra-articular prolotherapy was more effective in decreasing pain in these patients. [ABSTRACT FROM AUTHOR]

Purpose of Review: To reduce pain, improve function and possibly mitigate the risk for development of osteoarthritis in patients with functionally deficient meniscus pathology, meniscal allograft transplantation (MAT) can be used to restore native joint biomechanics and increase knee joint longevity. This review explores the senior author's preferred bridge-in-slot technique and recently published long-term clinical and radiographic outcomes following MAT. Recent Findings: Recent literature demonstrates MAT to be a safe and largely successful procedure for patients with functional meniscus deficiency. A majority of patients reach established minimal clinically important difference (MCID) values. Graft survivorship is approximately 80% at 10 years, significantly delaying and in some cases, preventing the need for future joint reconstruction procedures in these young patients. Return to sport rates are over 70%, revealing meniscal allografts can withstand high impact activities. Cartilage damage at the time of MAT increases the risk for graft and clinical failure, though this may be mitigated with a concomitant cartilage restoration procedure. Summary: Meniscal allograft transplantation can provide a durable and effective long-term solution to meniscal deficiency in symptomatic patients who wish to decrease the risk of symptomatic progression and possibly further osteoarthritis and continue activities of daily life and sports with less pain and more function. By restoring more normal joint biomechanics, MAT can mitigate the potential need for future knee arthroplasty in this young active patient population. [ABSTRACT FROM AUTHOR]

Background: Distal femur osteotomies are a well known and valuable treatment option to manage valgus malalignment with unicompartmental arthritis. Early postoperative complications are well known, and risk factors, such as pulmonary diseases, smoke, high dependent functional status, and body mass index, have been studied, but no study is available about osteotomies when gait is abnormal because of neurodegenerative conditions or when mineral density is below the normal rate. Case presentation: We report the case of a 44 year-old female Mediterranean patient who underwent a biplanar distal femur opening wedge osteotomy surgery following a lateral meniscus total removal, which led to the subsequent development of lateral compartment osteoarthritis and pain, despite general comorbidities, such as multiple sclerosis. Additionally, 2 months later a supracondylar femur fracture above the previously applied Tomofix® plate was reported. Fracture was treated by applying a LCP condylar 16 hole (336 mm) plate, a structural fibular graft, and strut fibular graft on the opposite side. Conclusion: The overall aim of this case report is to provide a lesson to surgeons who want to perform a realignment surgery of the lower limb in patients with abnormal gait. Not only mechanical axes are to be considered, but also bone density, patient's gait, and load force distribution along the bone stock. Emerging literature on three-dimensional cutting guides fails to account for these factors, thus promoting a standardized approach to surgery across all patients. The present case highlights a patient with low bone density and abnormal force distribution resulting from a pathologic neurodegenerative gait. In such cases, treatment decisions must carefully consider the biomechanical vulnerabilities of the native bone and the distribution of vector forces. These conditions must lead the choice toward a longer plate if an osteotomy is indicated, because surgery is more likely to fail. [ABSTRACT FROM AUTHOR]

Background: There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation. Methods: Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups (A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically. Results: The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections. Conclusions: PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery. [ABSTRACT FROM AUTHOR]

Xanthoma typically occurs in the subcutaneous tissues, with rare cases of xanthoma in the joints. However, the case of knee joint osteonecrosis combined with xanthoma is even more uncommon. In this article, we described a 50-year-old female patient who suffered xanthoma in the knee joint on the basis of osteonecrosis of the knee joint. The primary clinical symptoms were knee joint pain and limited mobility. The patient initially received conventional treatment for osteonecrosis. However, there was no significant improvement. Later, we found a synovial xanthoma in the patient's knee. Finally, she underwent arthroscopic excision of the knee joint synovial xanthoma. Following the procedure, her VAS score decreased from 7 to 2, and knee joint mobility increased from 10–103° to 10–140°. Through our follow-up, the patient did not exhibit symptom recurrence. This case is valuable as it provides a feasible therapeutic approach for future clinical applications. [ABSTRACT FROM AUTHOR]

Background: Four out of five people living with osteoarthritis (OA) also suffer with at least one other long-term health condition. The complex interaction between OA and multiple long-term conditions (MLTCs) can result in difficulties with self-care, restricted mobility, pain, anxiety, depression and reduced quality of life. The aim of the MulTI-domain Self-management in Older People wiTh OstEoarthritis and Multi-Morbidities (TIPTOE) trial is to evaluate the clinical and cost-effectiveness of the Living Well self-management support intervention, co-designed with people living with OA, integrated into usual care, in comparison to usual care alone. Methods: TIPTOE is a multi-centre, two-arm, individually randomised controlled trial where 824 individuals over 65 years old with knee and/or hip joint pain from their OA affected joint and at least one other long-term health condition will be randomised to receive either the Living Well Self-Management support intervention or usual care. Eligible participants can self-refer onto the trial via a website or be referred via NHS services across Wales and England. Those randomised to receive the Living Well support intervention will be offered up to six one-to-one coaching sessions with a TIPTOE-trained healthcare practitioner and a co-designed book. Participants will be encouraged to nominate a support person to assist them throughout the study. All participants will complete a series of self-reported outcome measures at baseline and 6- and 12-month follow-up. The primary outcome is symptoms and quality of life as assessed by the Musculoskeletal Health Questionnaire (MSK-HQ). Routine data will be used to evaluate health resource use. A mixed methods process evaluation will be conducted alongside the trial to inform future implementation should the TIPTOE intervention be found both clinically and cost-effective. An embedded 'Study Within A Project' (SWAP) will explore and address barriers to the inclusion of under-served patient groups (e.g. oldest old, low socioeconomic groups, ethnic groups). Discussion: TIPTOE will evaluate the clinical and cost-effectiveness of a co-designed, living well personalised self-management support intervention for older individuals with knee and/or hip OA and MLTCs. The trial has been designed to maximise inclusivity and access. Trial registration: ISRCTN 16024745. Registered on October 16, 2023. [ABSTRACT FROM AUTHOR]

Background: Despite advances in total knee arthroplasty, many patients are still unsatisfied with the functional outcome. Multibody simulations enable a more efficient exploration of independent variables compared to experimental studies. However, to what extent numerical models can fully reproduce knee joint kinematics is still unclear. Hence, models must be validated with different test scenarios before being applied to biomechanical questions. Methods: In our feasibility study, we analyzed a human knee specimen on a six degree of freedom joint simulator, applying a passive flexion and different laxity tests with sequential states of ligament resection while recording the joint kinematics. Simultaneously, we generated a subject-specific multibody model of the native tibiofemoral joint considering ligaments and contact between articulating cartilage surfaces. Results: Our experimental data on the sequential states of ligament resection aligned well with the literature. The model-based knee joint kinematics during passive flexion showed good agreement with the experiment, with root-mean-square errors of less than 1.61 mm for translations and 2.1° for knee joint rotations. During laxity tests, the experiment measured up to 8 mm of anteroposterior laxity, while the numerical model allowed less than 3 mm. Conclusion: Although the multibody model showed good agreement to the experimental kinematics during passive flexion, the validation showed that ligament parameters used in this feasibility study are too stiff to replicate experimental laxity tests correctly. Hence, more precise subject-specific ligament parameters have to be identified in the future through model optimization. [ABSTRACT FROM AUTHOR]

Introduction: Osteoarthritis (OA) is a chronic inflammatory disease where pro-inflammatory cytokines, damage-associated molecular patterns and macrophages play a crucial role. However, the interaction of these mediators, the exact cause, and the treatment of knee osteoarthritis (KOA) are still unclear. Moreover, the interaction of interleukin (IL)-33, platelet-derived growth factor-BB (PDGF-BB), and matrix metalloproteinase-9 (MMP-9) with other factors in the pathogenesis of KOA has not been elaborately explored. Method: Therefore, in this study, we analyzed the expression of IL-33, PDGF-BB, and MMP-9 in the knee cartilage tissue of model mice, murine KOA was induced by using the destabilization of the medial meniscus (DMM) model. Results: Compared with the sham operation control group, the expression levels of PDGF-BB, IL-33, and MMP-9 were increased significantly, and the pathological sections showed obvious cartilage damage. Additionally, we assessed the levels of IL-33 and MMP-9 expression in the knee joint of KOA model mice following intervention with PDGF-BB antibody, and we found that the expression level of MMP-9 was reduced following intervention with IL-33 antibody. When the effects of the three antibodies were compared in a mouse disease model, it was discovered that the IL-33 antibody could dramatically lower the relative expression level of MMP-9, resulting in the least amount of cartilage damage and improved protection. In conclusion, inhibiting IL-33 can significantly lower inflammatory factor levels in the knee joint, including IL-33 and MMP-9, and it can improve cartilage breakdown in osteoarthritis of the knee. Conclusion: Overall, the results indicate that IL-33 has a therapeutic function in the treatment of knee osteoarthritis and may be a novel target for treatment of the underlying causes of KOA. Additionally, PDGF-BB might be an upstream pathway of IL-33, and KOA's MMP-9 is an downstream pathway of IL-33. [ABSTRACT FROM AUTHOR]

Gait disorders in neurological diseases are frequently associated with spasticity. Intramuscular injection of Botulinum Toxin Type A (BTX-A) can be used to treat spasticity. Providing optimal treatment with the highest possible benefit–risk ratio is a crucial consideration. This paper presents a novel approach for predicting knee and ankle kinematics after BTX-A treatment based on pre-treatment kinematics and treatment information. The proposed method is based on a Bidirectional Long Short-Term Memory (Bi-LSTM) deep learning architecture. Our study's objective is to investigate this approach's effectiveness in accurately predicting the kinematics of each phase of the gait cycle separately after BTX-A treatment. Two deep learning models are designed to incorporate categorical medical treatment data corresponding to the injected muscles: (1) within the hidden layers of the Bi-LSTM network, (2) through a gating mechanism. Since several muscles can be injected during the same session, the proposed architectures aim to model the interactions between the different treatment combinations. In this study, we conduct a comparative analysis of our prediction results with the current state of the art. The best results are obtained with the incorporation of the gating mechanism. The average prediction root mean squared error is 2.99° ( R 2 = 0.85) and 2.21° ( R 2 = 0.84) for the knee and the ankle kinematics, respectively. Our findings indicate that our approach outperforms the existing methods, yielding a significantly improved prediction accuracy. [ABSTRACT FROM AUTHOR]

Total knee arthroplasty (TKA) is a well-established and successful treatment option for patients with end-stage osteoarthritis of the knee, providing high patient satisfaction. Robotic systems have been widely adopted to perform TKA in orthopaedic centres. The exact spatial positions of the femur and tibia are usually determined through pinned trackers, providing the surgeon with an exact illustration of the axis of the lower limb. The drilling of holes required for mounting the trackers creates weak spots, causing adverse events such as bone fracture. In the presented computational feasibility study, time differential electrical impedance tomography is used to locate the femur positions, thereby the difference in conductivity distribution between two distinct states s 0 and s 1 of the measured object is reconstructed. The overall approach was tested by simulating five different configurations of thigh shape and considered tissue conductivity distributions. For the cylinder models used for verification and reference, the reconstructed position deviated by about ≈ 1 mm from the actual bone centre. In case of models mimicking a realistic cross section of the femur position deviated between 7.9 mm 24.8 mm. For all models, the bone axis was off by about φ = 1.50 ° from its actual position. [ABSTRACT FROM AUTHOR]

Excessive muscle co-contraction is one of the factors related to the progression of knee osteoarthritis (OA). A previous study demonstrated that pain, joint instability, lateral thrust, weight, and lower extremity alignment were listed as factors affecting excessive co-contraction in knee OA. However, this study aimed to assess the association between fear-avoidance beliefs and muscle co-contraction during gait and stair climbing in people with knee OA. Twenty-four participants with knee OA participated in this cross-sectional study. Co-contraction ratios (CCRs) were used to calculate muscle co-contraction during walking and stair climbing, using surface electromyography. Fear-avoidance beliefs were assessed by the Tampa Scale for Kinesiophobia-11 (TSK-11) for kinesiophobia and the Pain Catastrophizing Scale (PCS) for pain catastrophizing. Secondary parameters that may influence co-contraction, such as degree of pain, lateral thrust, weight, and lower extremity alignment, were measured. The relationships between the CCR during each movement, TSK-11, and PSC were evaluated using Spearman's rank correlation coefficient and partial correlation analysis, adjusted by weight and lower extremity alignment. Partial correlation analysis showed a significant correlation only between medial muscles CCR and TSK-11 during stair descent (r = 0.54, p < 0.05). Our study revealed that kinesiophobia could be associated with co-contraction during stair descent in people with knee OA. [ABSTRACT FROM AUTHOR]

Objective: Osteoarthritis is linked to dementia, but no longitudinal studies have established this connection. This prospective cohort study from the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS) aimed to determine if knee osteoarthritis (KOA) independently predicts dementia in adults aged 65 and above. Methods: Participants were classified by the Kellgren–Laurence scale into no/minimal KOA (grades 0 and I) and definitive KOA (grade II or higher). We analyzed dementia incidence from 2009 to 2015 using long-term care insurance data, adjusting for age, sex, vascular risks, depressive symptoms, and activity levels. Results: Out of 1089 participants (58.9% female, average age 72.5), 72.0% had definitive KOA. Dementia occurrence was significantly higher in the definitive group (8.4%) compared to the no/minimal group (3.0%) (p < 0.001). A log-rank test and Cox regression analysis confirmed these findings, showing an adjusted hazard ratio of 2.29 (confidence interval: 1.12–4.68) for dementia in those with definitive KOA. Conclusions: These results suggest that KOA is a significant risk factor for dementia, highlighting the importance of addressing contributing factors in KOA patients to potentially slow the progression of dementia. [ABSTRACT FROM AUTHOR]

While conventional radiography and MRI have a well-established role in the assessment of patients with knee osteoarthritis, ultrasound is considered a complementary and additional tool. Moreover, the actual usefulness of ultrasound is still a matter of debate in knee osteoarthritis assessment. Despite that, ultrasound offers several advantages and interesting aspects for both current clinical practice and future perspectives. Ultrasound is potentially a helpful tool in the detection of anomalies such as cartilage degradation, osteophytes, and synovitis in cases of knee osteoarthritis. Furthermore, local diagnostic and minimally invasive therapeutic operations pertaining to knee osteoarthritis can be safely guided by real-time ultrasound imaging. We are constantly observing a growing knowledge and awareness among radiologists and other physicians, concerning ultrasound imaging. Ultrasound studies can be extremely useful to track the response to various therapies. For this specific aim, tele-ultrasonography may constitute an easy tool aiding precise and repeated follow-up controls. Moreover, raw radio-frequency data from US backscattering signals contain more information than B-mode imaging. This paves the way for quantitative in-depth analyses of cartilage, bone, and other articular structures. Overall, ultrasound technologies and their rapid evolution have the potential to make a difference at both the research and clinical levels. This narrative review article describes the potential of such technologies and their possible future implications. [ABSTRACT FROM AUTHOR]

Background/Objectives: Patellofemoral syndrome is a common osteoarticular condition that affects many individuals. Various treatment options are available, with a significant emphasis on targeted muscle-strengthening exercises. The purpose of this study was to investigate the effect of isokinetic muscle strengthening on muscle strength, joint range of motion, quality of life, physical performance, and pain tolerance in overweight/obese women with patellofemoral syndrome. Methods: Twenty-four overweight or obese women with patellofemoral syndrome participated in the study during September and October 2023 in a private medical facility for physical medicine and functional rehabilitation. They were randomly assigned to one of two groups for six weeks of isokinetic muscle strengthening. The first group (ISO.G) followed a rehabilitation program combined with isokinetic muscle strengthening. A second group (PCM.G) followed a rehabilitation program that includes an isokinetic protocol in passive compensation movement. The extensors' peak torque was measured before and after training. Results: The flexors' peak torque, stair climbing test, 10 m walk, chair lift, monopodal support, goniometric knee flexion test, heel–buttock distance measurement, pain, and quality of life scores improved significantly in both groups. The ISO.G, on the other hand, benefited from a significant increase in quadriceps muscle strength revealed by the extensors' peak torque. Conclusions: For the treatment of patellofemoral syndrome, isokinetic muscle strengthening in concentric mode appears to have a significant advantage over the classic rehabilitation program with isokinetic passive compensation, particularly in muscle strength gain, in addition to the improvement of joint range of motion, quality of life, physical performance, and pain tolerance. Isokinetic training may be recommended as a beneficial approach for the rehabilitative treatment of patellofemoral pain syndrome in overweight/obese women. [ABSTRACT FROM AUTHOR]

Since the role of the menisci in knee stability, proprioception, and homeostasis has been well established, significant efforts have been made to repair meniscal tears, resulting in excellent clinical outcomes and a reduction in the progression of knee osteoarthritis (OA). However, varying failure rates have been reported, raising questions regarding the healing potential in cases of complex injuries, poorly vascularized and degenerated areas, and generally in the presence of unfavorable biological characteristics. Therefore, over the last few decades, different strategies have been described to increase the chances of meniscal healing. Biological augmentation of meniscal repair through various techniques represents a safe and effective strategy with proven clinical benefits. This approach could reduce the failure rate and expand the indications for meniscal repair. In the present study, we thoroughly reviewed the available evidence on meniscal repair surgery and summarized the main techniques that can be employed to enhance the biological healing potential of a meniscal lesion. Our aim was to provide an overview of the state of the art on meniscal repair and suggest the best techniques to reduce their failure rate. [ABSTRACT FROM AUTHOR]

Background: Human adipose-derived stem cells (ADSCs) exert a strong anti-inflammatory effect, and synovium-derived stem cells (SDSCs) have high chondrogenic potential. Thus, this study aims to investigate whether a combination of human ADSCs and SDSCs will have a synergistic effect that will increase the chondrogenic potential of osteoarthritis (OA) chondrocytes in vitro and attenuate the cartilage degeneration of early and advanced OA in vitro. Methods: ADSCs, SDSCs, and chondrocytes were isolated from OA patients who underwent total knee arthroplasty. The ADSCs–SDSCs mixed cell ratios were 1:0 (ADSCs only), 8:2, 5:5 (5A5S), 2:8, and 0:1 (SDSCs only). The chondrogenic potential of the OA chondrocytes was evaluated in vitro with a transwell assay or pellet culture with various mixed cell groups. The mixed cell group with the highest chondrogenic potential was then selected and injected into the knee joints of nude rats of early and advanced OA stages in vivo. The animals were then evaluated 12 and 20 weeks after surgery through gait analysis, von frey test, microcomputed tomography, MRI, and immunohistochemical and histological analyses. Finally, the mechanisms underlying these findings were investigated through the RNA sequencing of tissue samples in vivo and Western blot of the OA chondrocyte autophagy pathway. Results: Among the MSCs treatment groups, 5A5S had the greatest synergistic effect that increased the chondrogenic potential of OA chondrocytes in vitro and inhibited early and advanced OA in vivo. The 5A5S group significantly reduced cartilage degeneration, synovial inflammation, pain sensation, and nerve invasion in subchondral nude rat OA, outperforming both single-cell treatments. The underlying mechanism was the activation of chondrocyte autophagy via the FoxO1 signaling pathway. Conclusion: A combination of human ADSCs and SDSCs demonstrated higher potential than a single type of stem cell, demonstrating potential as a novel treatment for OA. [ABSTRACT FROM AUTHOR]

Background: This study investigates the effectiveness of a self-developed intelligent monitoring system for home-based knee rehabilitation following total knee arthroplasty (TKA). Methods: In this randomized controlled trial, 120 patients undergoing TKA were divided using random digit allocation. Preoperative and one-month postoperative assessments of knee function, quality of life, and isometric knee extension strength were conducted with the Intelligent Monitoring System. Patients received group-specific rehabilitation instructions pre-discharge and performed exercises for one month. Results: Changes in isometric knee extensor strength on the affected side within one month post-surgery for the brace-monitored rehabilitation group showed a significant decrease three days after surgery compared to one day before surgery. Subsequent measurements taken at postoperative days 5, 7, 14, and 21 indicated a gradual increase in strength, although these increases did not reach statistical significance when compared with previous measurements. One month post-surgery, all groups demonstrated significant improvements in knee joint function and mobility compared to pre-surgery levels. Notably, the brace-monitored group showed statistically significant improvements in 36-Item Short-Form Health Survey (SF-36) scores over the conventional rehabilitation group. Conclusions: The Intelligent Monitoring System provides effective real-time monitoring and guidance for home-based knee rehabilitation post-TKA. It significantly enhances knee joint function, isometric knee extension strength, and quality of life shortly after surgery compared to traditional rehabilitation methods. This system offers a promising approach for improving postoperative recovery in TKA patients. Trial registration: This study was approved by the Medical Ethics Committee of Xiangya Hospital, Central South University (Ethics Approval Number 202209008-2). It was registered with the China Clinical Trial Registry, a primary registry of the World Health Organization's International Clinical Trials Registry Platform (Registration Number ChiCTR2300068852). [ABSTRACT FROM AUTHOR]

This study investigated whether differences in survival rates and clinical outcomes exist in patients undergoing TKA by insurance type: National Health Insurance (NHI) vs. Medical Aid Program (MAP). This study conducted a retrospective analysis of 762 TKAs (NHI, n = 505; MAP, n = 257) with a mean follow-up of 8.4 ± 1.8 years. Patient-reported outcomes (PROMs) were evaluated using the American Knee Society's (AKS) score at the final follow-up. The survival rate of each group was analyzed using Kaplan–Meier survival analysis. Any postoperative complications and readmissions within 90 days of discharge were recorded and compared between the groups. There were no between-group differences in pre- to postoperative improvement in AKS scores. The estimated 10-year survival rates were 98.5% in the NHI group and 96.9% in the MAP group, respectively, with no significant differences (p = 0.48). However, the length of hospital stay (LOS) was significantly longer in the MAP group than in the NHI group (13.4 days vs. 13.1 days, p = 0.03), and the transfer rate to other departments was significantly higher in the MAP group than in the NHI group (3.9% vs. 1.4%, p = 0.04). Readmission rates for orthopedic complications for 90 days were 3.0% in the NHI group and 3.5% in the MAP group, respectively (p = 0.67). Patients' insurance type showed similar survival rates and clinical outcomes to those of primary TKA at a mean follow-up of 8.4 years, but the LOS and rate of transfer to other departments during hospitalization were influenced by insurance type. [ABSTRACT FROM AUTHOR]

Introduction: Infrared thermography is gaining attention in the field of sports medicine and performance. This study investigated the effects of static and dynamic warm-ups and a 90° change of direction (COD) exercise on the thermal response of the knee. Methods: Thermograms were collected using the FlIR E54 Imaging Camera from 85 healthy young adults, 46 men and 39 women, aged 20-31 years. The participants were divided in two groups, static and dynamic warm-up. Four thermograms were taken: baseline (T0), warm-up (T1), COD (T2), and rest (T3). Four regions of interest (ROIs) of the knee were analyzed: anterior upper half (AUH), anterior lower half (ALH), posterior upper half (PUH), and posterior lower half (PLH). Mixed ANOVA with the Bonferroni-Holm test and independent t-test were used for pairwise comparison and to spot differences between the right and left knees at T1 and T2 and at T0 between men and women, respectively. Results: The mixed ANOVA was significant for time points (p< 0.001) in all the ROIs and for the stretching/temperature interaction with different levels of significance. The t-test results for the right and left knees at T1 and T2 were not significant. The temperature in the static warm-up group followed a decrease at T1, a subsequent decrease at T2, and a recovery similar to the baseline at T3, in the ALH in men and women and in the PUH only in men. Conclusion: Static stretching was more suitable for preparing the knee for the COD exercise than the dynamic one in terms of the thermal response. [ABSTRACT FROM AUTHOR]

Background: Chronic knee pain in older adults is a prevalent condition that significantly impacts quality of life. Transcranial Direct Current Stimulation (tDCS) has emerged as a potential non-invasive treatment option. This scoping review aims to evaluate the efficacy of tDCS in treating chronic knee pain among older adults. Methods: A comprehensive search of peer-reviewed articles was conducted, focusing on randomized controlled trials and pilot studies. Studies were included if they met specific Population, Concept, and Context (PCC) criteria. The primary outcomes assessed were pain reduction and functional improvement. Results: Eleven studies met the inclusion criteria, with a total of 779 participants. However, the results varied across studies, with some showing minimal differences between active tDCS and sham treatments. Advanced neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), provided insights into the neuromodulatory effects of tDCS, revealing changes in brain activity related to pain perception. Conclusions: Transcranial Direct Current Stimulation (tDCS) presents a promising avenue for treating chronic knee pain in elderly individuals. However, the current body of research offers mixed results, emphasizing the need for more extensive and standardized studies. Future research should focus on understanding the underlying mechanisms, optimizing treatment protocols, and exploring the long-term effects and safety of tDCS. [ABSTRACT FROM AUTHOR]

A cross-sectional study was conducted to biomechanically characterize Isabel's workout (30 snatch repetitions with 61 kg fixed weight), focusing on eventual changes in knee, hip and shoulder angles. A three-dimensional markerless motion capture system was used to collect data from 11 highly trained male crossfitters along the Isabel workout performed at maximal effort. The routine was analyzed globally and in initial, middle and final phases (10, 20 and 30 repetitions, respectively). Lift total time increased (1.51 ± 0.18 vs. 1.97 ± 0.20 s) and maximal lift velocity (2.64 ± 0.12 vs. 2.32 ± 0.13 m/s) and maximal lift power (15.58 ± 2.34 vs. 13.80 ± 2.49 W/kg) decreased from the initial to final phases, while the time from lift until the bar crossed the hip and shoulder (34.20 ± 4.00 vs. 27.50 ± 5.10 and 39.70 ± 16.80 vs. 30.90 ± 13.90%) decreased along the Isabel workout. In addition, a decrease in hip flexion was observed during the last two phases when the bar crosses the knee (62.62 ± 24.80 vs. 53.60 ± 19.99°). Data evidence a decrease in the power profile and a change in hip flexion throughout the Isabel workout, without compromising the other joints. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion Posterior condylar offset (PCO) and anterior condylar offset (ACO) exert an influence on the sagittal alignment in total knee arthroplasty (TKA). However, there is no common consensus that the variation range of posterior condylar offset (PCO) is associated with patient‐reported outcome measures (PROMs) and the optimum variation range of PCO. This study aims to investigate the correlation between PCO and the PROMs of primary TKA for osteoarthritis (OA) and find out the optimal variation range of the PCO.In this study, we performed a radiographic analysis of 106 patients (112 knees) with primary TKA. Patients were divided into two cohorts (A and B) according to the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Correlations between the sagittal parameter and WOMAC were investigated using univariate and multivariate analysis. The receiver operating characteristic (ROC) curve was used to establish the cut‐off value for the optimal variation range. We then further investigated how different variation range affects the WOMAC subscale score and forgotten‐joint‐score‐12 (FJS‐12).Univariate analysis revealed a correlation between the variation range of PCO (p < 0.01), ACO (p < 0.01) and PROMs. Multivariate analysis showed that only PCO was associated with PROMs. In the ROC graph, the cut‐off value of the variation range of PCO is 2.85 mm (AUC = 0.66, Youden index = 0.26). The WOMAC functional ability score of the group outside the PCO variation range of 2.85 mm significantly increased compared to the group within the range.In this study, PCO variation was significantly associated with clinical outcomes in TKA and the optimal PCO variation range was within 2.85 mm. Maintaining the PCO variation within 2.85 mm could enhance functional recovery and patient satisfaction. [ABSTRACT FROM AUTHOR]