Most patients gain weight in the 2 years after total knee arthroplasty: comparison to a healthy control group

SummaryObjectiveWhile joint arthroplasty improves the functional ability of persons with severe knee osteoarthritis (OA), the long-term effects of surgical intervention on body mass have not been evaluated. The objective of this study was to determine if a reduction in body mass index (BMI) was present following unilateral total knee arthroplasty (TKA) compared to an age-matched healthy control group who did not have surgery.MethodOne hundred and six adults with unilateral, end-stage knee OA and thirty-one persons without knee pain participated in the prospective longitudinal study. Subjects with OA underwent primary unilateral TKA and received post-operative out-patient physical therapy. Height, weight, quadriceps strength and self-perceived functional ability were measured at baseline and at a 2-year follow-up.ResultsThere was a significant interaction effect between body mass over time and subject group (P=0.017). BMI showed a significant increase over 2 years for the surgical group (P<0.001), but not for the control group (P=0.842). Sixty-six percent of the persons in the surgical group gained weight over the 2 years with an average weight gain of 6.4kg, or 14 pounds, 2 years after their initial physical therapy visit. Educational level, marital status, income level and activity level prior to surgery were not related to post-surgical weight gain.ConclusionThe majority of subjects gain weight after surgery and this cannot be attributed to the effects of aging. Weight gain after TKA should be treated as an independent concern and management of orthopedic impairments will not result in weight loss. Post-operative care should include access to nutrition or weight management professionals in addition to medical and physical therapy services

Gait, function and quadriceps strength after intraarticular hyaluronan injections in patients with symptomatic knee osteoarthritis

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenIntroduction: Knee OA is a common cause of decline in function and is generally associated with joint malalignment and laxity, joint space narrowing, quadriceps weakness, as well as sclerosis and attrition of subchondral bone. Intraarticular (IA) injections of Hyaluronic Acid (HA) are indicated to palliate symptoms and improve function in patients with knee OA. Primary outcome measures in studies on the efficacy of this treatment are largely self reports of pain and function. The purpose of the study was to investigate the effects of HA injections on knee function and sagittal plane kinematics in patients with knee OA. Materials and Methods: Thirteen subjects with symptomatic knee OA and scheduled for 5, weekly, IA injections of HA were recruited. Each subject was tested for baseline data. Posttreatment testing sessions were conducted within 3 weeks of finishing the series of HA and again five months after treatment. Kinematic data were collected at 120 Hz using an eight camera motion analysis system (VICON, Oxford Metrics). Subjects walked along a 10 m walkway at self-selected pace. Ten walking trials were collected and averaged. Knee function was assessed with a knee specific questionnaire (Knee Outcome Survey (KOS)), goniometric range of motion (ROM) measures, a six minute walk (6MW) and a timed stair climbing task. Quadriceps strength was evaluated isometrically at 90° with a KinCom dynamometer (Chattanooga Group, Inc., Chattanooga, TN) and expressed as a ratio of the force output of the involved vs. uninvolved side (Quadriceps Index (QI)). Repeated measures analysis of variance (ANOVA) with pairwise comparisons, multivariate analysis, linear regression analysis and paired t-tests were used to analyze the data. Alpha was set at 0.05. Results: Multivariate analysis of knee flexion angles was used at two stages of weight acceptance; initial contact (IC) and peak knee flexion (PKF) between involved (INV) and uninvolved (UNINV) knees across the three testing times. The analysis showed an interaction between stage of weight acceptance and side (F=18.716; p=0.001). There were significant interlimb differences in knee excursion during weight acceptance (flexion angle from IC to PKF) for the first (5.3°; p=0.005), second (5.2°; p=0.001) and third (5.2°; p=0.001) testing times; the affected knee demonstrating less movement. Excursions of the INV and the UNINV knees did not change across testing times. Multivariate analysis of goniometric total knee ROM between the INV and UNINV knee across testing times showed an interaction by side (F=29.996; p<0.001) but not for testing time. The INV knee’s ROM was on average 8° less than that of the UNINV at the first testing session (p=0.003), 5.2° less at the second (p<0.001) and 7.2° less at the third testing session (p=0.001). Knee ROM of either knee did not change across testing times. Larger knee flexion ROM at baseline predicted greater improvement on KOS scores on the first post-treatment testing session (r2=.540; p=0.004). Larger knee flexion ROM at the first post-treatment predicted greater improvements on KOS scores at the later testing session (r2=.398; p=0.021). Significant within-subjects effects of testing times on KOS scores were found(F=4.65; p=0.02),on 6MW distance (F=12.010; p<0.001) and QI (F=5.903; p=0.013). Discussion: Subjects demonstrated significantly improved function after a series of intra-articular hyaluronan injections as evaluated with the KOS and functional testing. Kinematic interlimb differences were unchanged across testing times despite these improvements. Goniometric measures of total knee range of motion confirmed interlimb differences in available joint ROM. Although subjects demonstrated ample functional ROM, this was not utilized during weight acceptance. The truncated knee flexion may impede the shock absorbing mechanism of the knee and impact the progression of knee OA. While improvements in self reported scores were not maintained at the 5 month evaluation, walking distance continued to improve over time. This indicates that functional improvements persisted despite concurrently increasing symptoms

ACL injury and reconstruction affect control of ground reaction forces produced during a novel task that simulates cutting movements

After anterior cruciate ligament (ACL) injury and reconstruction, biomechanical and neuromuscular control deficits persist and 25% of those who have experienced an ACL injury will experience a second ACL rupture in the first year after returning to sports. There remains a need for improved rehabilitation and the ability to detect an individual\u27s risk of secondary ACL rupture. Nonlinear analysis metrics, such as the largest Lyapunov exponent (LyE) can provide new biomechanical insight in this population by identifying how movement patterns evolve over time. The purpose of this study was to determine how ACL injury, ACL reconstruction (ACLR), and participation in high-performance athletics affect control strategies, evaluated through nonlinear analysis, produced during a novel task that simulates forces generated during cutting movements. Uninjured recreational athletes, those with ACL injury who have not undergone reconstruction (ACLD [ACL deficient]), those who have undergone ACL reconstruction, and high-performance athletes completed a task that simulates cutting forces. The LyE calculated from forces generated during this novel task was greater (ie, force control was diminished) in the involved limb of ACLD and ACLR groups when compared with healthy uninjured controls and high-performance athletes. These data suggest that those who have experienced an ACL injury and subsequent reconstructive surgery exhibit poor force control when compared with both uninjured controls and high-performance athletes. Clinical significance: significantly larger LyE values after ACL injury and reconstruction when compared with healthy athletes suggest a continuing deficit in force control not addressed by current rehabilitation protocols and evaluation metrics that could contribute to secondary ACL rupture

Early Quadriceps Strength Loss After Total Knee Arthroplasty : The Contributions of Muscle Atrophy and Failure of Voluntary Muscle Activation

While total knee arthroplasty reduces pain and provides a functional range of motion of the knee, quadriceps weakness and reduced functional capacity typically are still present one year after surgery. The purpose of the present investigation was to determine the role of failure of voluntary muscle activation and muscle atrophy in theearly loss of quadriceps strength after surgery

Social ageing: exploring the drivers of late-life changes in social behaviour in mammals

This is the final version. Available from The Royal Society via the DOI in this record. No datasets were generated or analysed during the current study.Social interactions help group-living organisms cope with socio-environmental challenges and are central to survival and reproductive success. Recent research has shown that social behaviour and relationships can change across the lifespan, a phenomenon referred to as 'social ageing'. Given the importance of social integration for health and well-being, age-dependent changes in social behaviour can modulate how fitness changes with age and may be an important source of unexplained variation in individual patterns of senescence. However, integrating social behaviour into ageing research requires a deeper understanding of the causes and consequences of age-based changes in social behaviour. Here, we provide an overview of the drivers of late-life changes in sociality. We suggest that explanations for social ageing can be categorized into three groups: changes in sociality that (a) occur as a result of senescence; (b) result from adaptations to ameliorate the negative effects of senescence; and/or (c) result from positive effects of age and demographic changes. Quantifying the relative contribution of these processes to late-life changes in sociality will allow us to move towards a more holistic understanding of how and why these patterns emerge and will provide important insights into the potential for social ageing to delay or accelerate other patterns of senescence.National Institute of HealthNational Institute of Healt

Total Knee Arthroplasty Assessments Should Include Strength and Performance-Based Functional Tests to Complement Range-of-Motion and Patient-Reported Outcome Measures

Range of motion (ROM) and pain often define successful recovery after total knee arthroplasty (TKA), but these routine clinical outcomes correlate poorly or not at all to functional capacity after TKA. The purpose of this Perspective is to underscore the importance of muscle strength and performance-based functional tests in addition to knee ROM and patient-reported outcome (PRO) measures to evaluate outcomes after TKA. Specifically: (1) muscle strength is the rate-limiting step for recovery of function after TKA; (2) progressive rehabilitation targeting early quadriceps muscle strengthening improves outcomes and does not compromise ROM after TKA; (3) ROM and PROs fail to fully capture functional limitations after TKA; and (4) performance-based functional tests are critical to evaluate function objectively after TKA. This Perspective also addresses studies that question the need for or benefit of physical therapy after TKA because their conclusions focus only on ROM and PRO measures. Future research is needed to determine the optimal timing, delivery, intensity, and content of physical therapy

Don’t Peak Too Early : Evidence for an ACL Injury Prevention Mechanism of the 11+ Program

Funding Information: Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (award number R01AR072034). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work was also supported by grant R37-HD037985 from the National Institute of Health. This work was supported by the Ice-landic Research Fund, grant numbers 120410021, 903271305, 1203250031, and 185359051. Funding Information: Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (award number R01AR072034). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work was also supported by grant R37-HD037985 from the National Institute of Health. This work was supported by the Icelandic Research Fund, grant numbers 120410021, 903271305, 1203250031, and 185359051. Publisher Copyright: © 2022, North American Sports Medicine Institute. All rights reserved.Background The 11+ program prevents anterior cruciate ligament (ACL) injuries in athletes through unknown mechanisms. Purpose The aim of the current study was to evaluate the effects of The 11+ intervention program, performed by female soccer players during a single season, on the frequency of Early Peaks during athletic tasks. Methods Three teams (69 players) of collegiate female soccer athletes (Divisions I and II) were recruited. Two teams (49 players) volunteered to perform The 11+ three times per week for one season (~22 weeks plus three weeks pre-season), and one team (20 players) served as controls. The athletes performed three repetitions of a cutting maneuver, side shuffle direction change, and forwards to backwards running direction change before and after the competitive season and were recorded using marker-based 3D motion capture. Knee valgus moment time series were calculated for each repetition with inverse kinematics and classified as either “Very Early Peak”, “Early Peak” or “other” using cluster analysis. The classification was based timing of the peak relative to the timing of ACL injuries. The effect of the intervention on the frequency of Very Early Peaks and Early Peaks was evaluated with a mixed Poisson regression controlling for the movement task and pre-season frequency. Results The 11+ intervention reduced the frequency of Early Peak knee valgus moment in one intervention team (coefficient =-1.16, p = 0.004), but not the other (coefficient =-0.01, p = 0.977). No effect was observed on the frequency of Very Early Peak knee valgus moment. Conclusions Reduced frequency of knee valgus moment Early Peak during athletic tasks may explain the mechanism by which The 11+ program decreases risk of ACL injury. Prospective studies with a much larger sample size are required to establish a link between Early Peak knee valgus moments and risk of ACL injury. Level of evidence 2b.Peer reviewe