Muscle forces are difficult to measure in vivo, so the force-generating capacity of muscles is commonly inferred from muscle architecture. It is often assumed, implicitly or explicity, that a muscle’s maximum force-generating capacity is proportional to physiological cross-sectional area (PCSA), and that a muscle’s operating range is proportional to mean optimal fascicle length. Here, we examined the effect of muscle architecture (PCSA and fascicle length) on muscle function (maximal isometric force and operating range) using a three-dimensional finite element model which accounts in a mechanically consistent way for muscle deformation and other complexities of muscle contraction. By varying architectural properties independently, it was shown that muscle force-generating capacity does not scale by the same factor as PCSA, and that operating range does not scale by the same factor as optimal fascicle length. For instance, 3-fold independent variation of mean optimal fascicle length caused the maximum isometric force-generating capacity of the muscle to vary from 83% to 105% of the force predicted by PCSA alone. Non-uniformities in fascicle length that develop as the muscle deforms during contraction reduce muscle force and operating range. Thus, a three-dimensional finite element model that satisfies fundamental physical constraints predicts that the maximum force-generating capacity of skeletal muscle depends on factors other than PCSA, and that operating range depends on factors other than optimal fascicle length. These findings have implications for how the force-generating properties of animal muscles are scaled to human muscles, and for how the functional capacity of muscles is predicted from muscle architecture.

Measurements of muscle architecture are crucial for understanding muscle function but are often difficult to obtain in human muscles in vivo. This study aimed to create population-averaged atlases of human rotator cuff muscle shape and muscle fibre orientations from anatomical magnetic resonance images (MRI) and diffusion-weighted images (DWI) and to utilise these atlases to predict muscle fibre orientations from anatomical MRI data alone. An image registration framework was applied to coregister anatomical MRI and DWI data of 11 male and 9 female subjects into sex-specific common spaces, forming the basis for the atlases. The accuracy of registration was quantified using Dice coefficients, angular correlation coefficients (ACCs) and angular differences. The same metrics were used to assess the capability of the atlases to predict fibre orientations for subjects not included in the atlas construction, via leave-one-out cross-validation. The results showed that individual male and female image data were accurately registered into their respective atlas spaces, with high Dice coefficients (0.888 ± 0.002 for males, 0.856 ± 0.021 for females) and consistent angular alignment as evidenced by the ACCs and angular differences. Predicted fibre orientations for out-of-sample subjects closely matched those derived from DWI images, exhibiting improved smoothness and coverage (ACC: 0.909 ± 0.011 for males, 0.942 ± 0.011 for females; angular difference: 13.8° ± 1.3° for males, 11.2° ± 1.2° for females). These findings demonstrate that population-averaged atlases enhance muscle architecture reconstructions and enable the accurate prediction of muscle fibre orientations using only anatomical MRI scans in younger individuals without shoulder injuries.

Many children with cerebral palsy (CP) have muscle contractures and bony deformities. It has been hypothesised that these musculoskeletal abnormalities could increase or decrease muscle moment arms and cause movement dysfunction. In this study, we first investigated the relationship between skeletal growth (tibia length) and three-dimensional measurements of Achilles tendon and tibialis anterior moment arms from magnetic resonance images of 200 typically developing children aged 5 to 15 years. Moment arms increased linearly with tibia length. To determine whether cerebral palsy affects moment arms, we also measured Achilles tendon and tibialis anterior moment arms from a predominantly ambulant cohort of 79 children with CP (94% Gross Motor Function Classification System Level I or II). After adjusting for tibia length, age and sex, the Achilles tendon moment arms of children with cerebral palsy were, on average, slightly greater than those of typically developing children (mean difference 1.4 mm, 95% confidence interval (CI) 0.4 to 2.4; p < 0.01) and tibialis anterior moment arms were slightly smaller (mean difference -0.9 mm, 95% CI -1.6 to -0.2, p < 0.05). We conclude that moment arms scale linearly with tibia length during childhood development from 5 to 15 years. Ambulant children with cerebral palsy have moment arms that differ slightly, on average, from the moment arms of typically developing children, but those differences are too small to cause significant ankle joint dysfunction.

Skeletal muscles grow substantially during childhood. However, quantitative information about the size of typically developing children's muscles is sparse. Here, the objective was to construct muscle-specific reference curves for lower leg muscle volumes in children aged 5 to 15 y. Volumes of 10 lower leg muscles were measured from magnetic resonance images of 208 typically developing children and 78 ambulant children with cerebral palsy. Deep learning was used to automatically segment the images. Reference curves for typical childhood muscle volumes were constructed with quantile regression. The median total leg muscle volume of a 15-y-old child is nearly five times that of a 5-y-old child. Between the ages of 5 and 15, boys typically have larger muscles than girls, both in absolute terms (medians are greater by 5 to 20%) and per unit of body weight (1 to 13%). Muscle volumes vary widely between children of a particular age: the range of volumes for the central 80% of the distribution (i.e., between the 10th and 90th centiles) is more than 40% of the median volume. Reference curves for individual muscle volumes have a similar shape to reference curves for total lower leg muscle volume. Confidence bands about the centile curves were wide, especially at the youngest and oldest ages. Nonetheless, the reference curves can be used with confidence to identify small-for-age muscles (centile < 10). We show that 56% of children with cerebral palsy in our cohort had total lower leg muscle volumes that were small-for-age and that 80% had at least one lower leg muscle that was small-for-age.

Muscle volume must increase substantially during childhood growth to generate the power required to propel the growing body. One unresolved but fundamental question about childhood muscle growth is whether muscles grow at equal rates; that is, if muscles grow in synchrony with each other. In this study, we used magnetic resonance imaging (MRI) and advances in artificial intelligence methods (deep learning) for medical image segmentation to investigate whether human lower leg muscles grow in synchrony. Muscle volumes were measured in 10 lower leg muscles in 208 typically developing children (eight infants aged less than 3 months and 200 children aged 5 to 15 years). We tested the hypothesis that human lower leg muscles grow synchronously by investigating whether the volume of individual lower leg muscles, expressed as a proportion of total lower leg muscle volume, remains constant with age. There were substantial age-related changes in the relative volume of most muscles in both boys and girls (p < 0.001). This was most evident between birth and five years of age but was still evident after five years. The medial gastrocnemius and soleus muscles, the largest muscles in infancy, grew faster than other muscles in the first five years. The findings demonstrate that muscles in the human lower leg grow asynchronously. This finding may assist early detection of atypical growth and allow targeted muscle-specific interventions to improve the quality of life, particularly for children with neuromotor conditions such as cerebral palsy.

BackgroundPhysical therapists use diagnostic tests in a variety of settings. Choosing the best diagnostic test to apply in a particular situation can be difficult. The choice of diagnostic test should be informed, at least in part, by evidence of test accuracy. Finding evidence of diagnostic test accuracy has, until recently, been challenging. Ideally, there would exist a database that comprehensively indexes evidence on diagnostic tests relevant to physical therapy practice, is free to access, and is easy to use.ObjectiveThis Masterclass will describe the DiTA (Diagnostic Test Accuracy) database (dita.org.au) including its development and search interface, and provide advice on how to search and retrieve records.DiscussionDiTA indexes more than 2400 primary studies and systematic reviews of diagnostic test accuracy relevant to physical therapy practice. Users can search DiTA using text fields and dropdown lists to find evidence of diagnostic test accuracy. The database is freely accessible on the internet. Since its launch, DiTA has been accessed from almost every country in the world, the largest number of searches having been conducted from Brazil.

The human rotator cuff consists of four muscles, each with a complex, multipennate architecture. Despite the functional and clinical importance, the architecture of the human rotator cuff has yet to be clearly described in humans in vivo. The purpose of this study was to investigate the intramuscular, intermuscular, and interindividual variations in architecture and moment arms of the human rotator cuff. Muscle volumes, fascicle lengths, physiological cross-sectional areas (PCSAs), pennation angles, and moment arms of all four rotator cuff muscles were measured from mDixon and diffusion tensor imaging (DTI) scans of the right shoulders of 20 young adults. In accordance with the most detailed dissections available to date, we found substantial intramuscular variation in fascicle length (coefficients of variation (CVs) ranged from 26% to 40%) and pennation angles (CVs ranged from 56% to 62%) in all rotator cuff muscles. We also found substantial intermuscular and interindividual variations in muscle volumes, but relatively consistent mean fascicle lengths, pennation angles, and moment arms (CVs for all <= 17%). Moreover, when expressed as a proportion of total rotator cuff muscle volume, the volumes of individual rotator cuff muscles were highly consistent between individuals and sexes (CVs <= 16%), suggesting that rotator cuff muscle volumes scale uniformly, at least in a younger population without musculoskeletal problems. Together, these data indicate limited interindividual and intermuscular variability in architecture, which may simplify scaling routines for musculoskeletal models. However, the substantial intramuscular variation in architecture questions the validity of previously reported mean architectural parameters to adequately describe rotator cuff function. The human rotator cuff consists of four muscles, each with a complex, multipennate architecture. Despite the functional and clinical importance, the architecture of the human rotator cuff has yet to be clearly described in humans in vivo. In this study, we used advanced magnetic resonance imaging methods to quantify inter-individual, intermuscular, and intramuscular variations in three-dimensional architecture of human rotator cuff muscles.image

Exergame training, in which video games are used to promote exercise, can be tailored to address cognitive and physical risk factors for falls and is a promising method for fall prevention in older people. Here, we performed a randomized clinical trial using the smart±step gaming system to examine the effectiveness of two home-based computer game interventions, seated cognitive training and step exergame training, for fall prevention in community-dwelling older people, as compared with a minimal-intervention control group. Participants aged 65 years or older (n = 769, 71% female) living independently in the community were randomized to one of three arms: (1) cognitive training using a computerized touchpad while seated, (2) exergame step training on a computerized mat or (3) control (provided with an education booklet on healthy ageing and fall prevention). The rate of falls reported monthly over 12 months—the primary outcome of the trial—was significantly reduced in the exergame training group compared with the control group (incidence rate ratio = 0.74, 95% confidence interval = 0.56–0.98), but was not statistically different between the cognitive training and control groups (incidence rate ratio = 0.86, 95% confidence interval = 0.65–1.12). No beneficial effects of the interventions were found for secondary outcomes of physical and cognitive function, and no serious intervention-related adverse events were reported. The results of this trial support the use of exergame step training for preventing falls in community-dwelling older people. As this intervention can be conducted at home and requires only minimal equipment, it has the potential for scalability as a public health intervention to address the increasing problem of falls and fall-related injuries. Australian and New Zealand Clinical Trial Registry identifier: ACTRN12616001325493 . In a randomized clinical trial enrolling older people living in a community setting, exergame step training on a computerized mat, but not seated cognitive training, decreased the rate of falls over the course of a year, as compared to a control group provided with an education booklet on healthy aging and fall prevention.

Detailed analysis of skeletal muscle architecture provides insights into skeletal muscle function. To date, measurements of the human subscapularis architecture have been limited to cadaveric measurements. In this study we demonstrate the feasibility of using anatomically constrained fibre tractography to reconstruct and quantify the 3D architecture of the human subscapularis muscle, and provide the first quantitative measurements of the architecture of the human subscapularis muscle in vivo. mDixon and diffusion tensor magnetic resonance images were obtained from the right shoulders of 20 healthy young adults. Anatomically constrained fibre tractography, in which fascicle reconstructions were forced to terminate on the internal aponeurosis of the subscapularis, was used to reconstruct muscle fibre architecture of the subscapularis muscles. Qualitatively, architectural reconstructions resembled the known subscapularis anatomy well, demonstrating face validity of the reconstructions. Muscle architectural parameters (means ± SDs) were: muscle volume 138 ± 42 cm3, fascicle length 63.6 ± 5.9 mm, physiological cross-sectional area (PCSA) 22 ± 6 cm2, and pennation angle 16 ± 2°. Architectural measurements of the subscapularis fell within the range reported in cadaver studies and were relatively insensitive to variations in fibre tractography parameters. The anatomically detailed whole-muscle reconstructions can be used to quantify the effects of joint surgery on muscle architecture and to advance computational models of the human shoulder.

Abstract Objectives Exergame training is a promising method for delivering evidence-based fall prevention exercise as it can facilitate exercise adherence and can be tailored to address cognitive and motor risk factors for falls. This study examined the effectiveness of two home-based computer game interventions (seated brain training and step training; smart±step) in preventing falls in community-dwelling older people, compared to a minimal-intervention control group. Design Assessor-blinded, randomised controlled trial. Setting Research institute and homes of older people living in the community of Sydney, Australia. Participants 769 people aged 65+ years living independently in the community and free of cognitive impairment, progressive neurological disease, or any other unstable or acute medical condition that precludes exercise. Interventions Participants were randomised to one of three arms: brain training using a computerised touch pad while seated; exergame step training on a computerised mat; or control. The intervention groups were provided with a home-based training system and were asked to train for at least two hours per week over the 12-month trial. Main outcome measures The primary outcome was the rate of falls reported monthly over 12 months. Results Between October 2016 and May 2019, 769 participants were randomised (seated brain training =262, exergame step training=252, control=255) and all were included in the intention-to-treat analyses. The rate of falls over 12 months was significantly reduced in the exergame step training group compared to control (IRR=0.74, 95%CI=0.56 to 0.98) and was not statistically different between the seated brain training and control groups (IRR=0.86, 95%CI=0.65 to 1.12). No serious intervention-related adverse events were reported. Conclusions A home-based exergame step training program provides a safe and effective means for preventing falls in older people living in the community. As this intervention can be conducted at home and requires only minimal equipment, it has the potential for scalability as a public health intervention to address the increasing problem of falls and fall-related injuries. Trial registration Australian and New Zealand Clinical Trial Registry ACTRN12616001325493, registered 22 September 2016.

Study design Protocol for a multi-centre randomised controlled trial (the SCI-MT trial). Objectives To determine whether 10 weeks of intensive motor training enhances neurological recovery in people with recent spinal cord injury (SCI). Setting Fifteen spinal injury units in Australia, Scotland, England, Italy, Netherlands, Norway, and Belgium. Methods A pragmatic randomised controlled trial will be undertaken. Two hundred and twenty people with recent SCI (onset in the preceding 10 weeks, American Spinal Injuries Association Impairment Scale (AIS) A lesion with motor function more than three levels below the motor level on one or both sides, or an AIS C or D lesion) will be randomised to receive either usual care plus intensive motor training (12 h of motor training per week for 10 weeks) or usual care alone. The primary outcome is neurological recovery at 10 weeks, measured with the Total Motor Score from the International Standards for Neurological Classification of SCI. Secondary outcomes include global measures of motor function, ability to walk, quality of life, participants’ perceptions about ability to perform self-selected goals, length of hospital stay and participants’ impressions of therapeutic benefit at 10 weeks and 6 months. A cost-effectiveness study and process evaluation will be run alongside the trial. The first participant was randomised in June 2021 and the trial is due for completion in 2025. Conclusions The findings of the SCI-MT Trial will guide recommendations about the type and dose of inpatient therapy that optimises neurological recovery in people with SCI. Trial registration ACTRN12621000091808 (1.2.2021).

Little is known about the skeletal muscle architecture of living humans at birth. In this study, we used magnetic resonance imaging (MRI) to measure the volumes of ten muscle groups in the lower legs of eight human infants aged less than three months. We then combined MRI and diffusion tensor imaging (DTI) to provide detailed, high-resolution reconstructions and measurements of moment arms, fascicle lengths, physiological cross-sectional areas (PCSAs), pennation angles and diffusion parameters of the medial (MG) and lateral gastrocnemius (LG) muscles. On average, the total lower leg muscle volume was 29.2 cm3. The largest muscle was the soleus muscle with a mean volume of 6.5 cm3. Compared to the LG muscles, the MG muscles had, on average, greater volumes (by ∼35%) and greater PCSAs (by ∼63%) but similar ankle-to-knee moment arm ratios (∼0.1 difference), fascicle lengths (∼5.7 mm difference) and pennation angles (∼2.7° difference). The MG data were compared with data previously collected from adults. The MG muscles of adults had, on average, a 63-fold greater volume, a 36-fold greater PCSA, and 1.7-fold greater fascicle length. This study demonstrates the feasibility of using MRI and DTI to reconstruct the three-dimensional architecture of skeletal muscles in living human infants. It is shown that, between infancy and adulthood, MG muscle fascicles grow primarily in cross-section rather than in length.

ObjectivesTo determine the effect of arthroscopic capsular shift surgery on pain and functional impairment for people with atraumatic shoulder (glenohumeral) joint instability.MethodsWe conducted a randomised, placebo-controlled clinical trial in a specialist secondary care facility. Patients aged 18 years and over who reported insecurity (apprehension) in their shoulder joint and had evidence of capsulolabral damage on arthroscopic examination were included. Patients were excluded if their shoulder apprehension symptoms were precipitated by a high velocity shoulder injury, they had bony or neural damage, a rotator cuff or labral tear, or previous surgery on the symptomatic shoulder. Sixty-eight participants were randomised and received diagnostic arthroscopy, followed by arthroscopic capsular shift or diagnostic arthroscopy alone. All participants received the same postoperative clinical care. The primary outcome was pain and functional impairment measured with the Western Ontario Shoulder Instability Index. The prespecified minimum clinically important effect was a reduction in pain and disability of 10.4 points.ResultsMean reductions in pain and functional impairment for both groups were similar. Compared with diagnostic arthroscopy, arthroscopic capsular shift increased pain and functional impairment by means of 5 points (95% CI −6 to 16 points) at 6 months, 1 point (95% CI −11 to 13 points) at 12 months and 2 points (95% CI −12 to 17 points) at 24 months.ConclusionsCompared with diagnostic arthroscopy alone, arthroscopic capsular shift confers, at best, only minimal clinically important benefit in the medium term.Trial registration numberNCT01751490.

The early and intensive motor training (versus usual care) to enhance neurological recovery and function in people with spinal cord injury (SCI-MT) randomised clinical trial aims to determine whether 10 weeks of intensive motor training enhances neurological recovery in people with recent spinal cord injury (SCI). This statistical analysis plan pre-specifies the method of analysis for every outcome and key variable collected in the trial. The primary analysis will consist in a linear mixed model to estimate the between-group mean difference in Total Motor Scores at 10 weeks. The statistical analysis plan also describes planned sensitivity analyses including covariate adjustments, missing data handling and subgroup analyses.

Diffusion tensor magnetic resonance imaging (DT-MRI) was used to investigate the three-dimensional architecture and diffusion properties of medial gastrocnemius muscles in living human infants aged 2-3 months. Mean muscle volume, physiological cross-sectional area and fascicle length in infants were 1.8%, 3.8% and 47.2% of values previously obtained in 8 adult muscles. Radial diffusivity in infant muscle was half that in adult muscle, presumably because infant muscle fibres have much smaller transverse dimensions.

BACKGROUND:The objective of this study was to develop prediction models and explore the external validity of the models in a large sample of patients with chronic widespread pain (CWP) and fibromyalgia (FM).METHODS:Patients with CWP and FM referred to rehabilitation services in Norway (n = 986) self-reported data on potential predictors prior to entering rehabilitation, and self-reported outcomes at one-year follow-up. Logistic regression models of improvement, worsening and work status, and a linear regression model of health-related quality of life (HRQoL), were developed using lasso regression. Externally validated estimates of model performance were obtained from the validation set.RESULTS:The number of participants in the development and the validation sets was 771 and 215 respectively; only participants with outcome data (n = 519-532 and 185, respectively) were included in the analyses. On average, HRQoL and work status changed little over one year. The prediction models included 10-11 predictors. Discrimination (AUC statistic) for prediction of outcome at follow-up was 0.71 for improvement, 0.67 for worsening, and 0.87 for working. The median absolute error of predictions of HRQoL was 0.36 (0.22-0.51). Reasonably good predictions of working at follow-up and HRQoL could be obtained using only the baseline scores as predictors.CONCLUSIONS:Moderately complex prediction models (10-11 predictors) generated poor to excellent predictions of patient-relevant outcomes. Simple prediction models of working and HRQoL at follow-up may be nearly as accurate and more practical.SIGNIFICANCE:Prediction modelling of outcome in rehabilitation has been sparsely explored. Such models may guide clinical decision-making. This study developed and externally validated prediction models for outcomes of people with chronic widespread pain and fibromyalgia in a rehabilitation setting. Multivariable prediction models generated poor to excellent predictions of patient-relevant outcomes, but the complexity of these models may reduce their clinical utility. Simple univariable prediction models were nearly as accurate and may have more potential for use in clinical practice.

QUESTION:What are the effects of diagnostic labels and advice, and interactions between labels and advice, on perceived need for shoulder surgery for rotator cuff disease? DESIGN:2×2 factorial online randomised experiment. PARTICIPANTS:People with shoulder pain. INTERVENTION:Participants read a scenario describing a patient with rotator cuff disease and were randomised to bursitis label plus guideline-based advice, bursitis label plus treatment recommendation, rotator cuff tear label plus guideline-based advice, and rotator cuff tear label plus treatment recommendation. Guideline-based advice included encouragement to stay active and positive prognostic information. Treatment recommendation stressed that treatment is needed for recovery. OUTCOME MEASURES:Perceived need for surgery (primary outcome), imaging, an injection, a second opinion and to see a specialist; and perceived seriousness of the condition, recovery expectations, impact on work performance and need to avoid work. RESULTS:A total of 2,024 responses (99.8% of 2,028 randomised) were analysed. Labelling as bursitis (versus rotator cuff tear) decreased perceived need for surgery (mean effect -0.5 on a 0-to-10 scale, 98.3% CI -0.7 to -0.2), imaging and to see a specialist, and perceived seriousness of the condition and need to avoid work. Guideline-based advice (versus treatment recommendation) decreased perceived need for surgery (mean effect -1.0, 98.3% CI -1.3 to -0.7), imaging, an injection, a second opinion and to see a specialist, and perceived seriousness of the condition and recovery expectations. There was little to no evidence of an advice label interaction for any outcome. CONCLUSION:Labels and advice influenced perceived need for surgery and other secondary outcomes in people with rotator cuff disease, with larger effects for advice. There was evidence of little or no interaction between labels and advice for any outcome, but the additive effect of labels and advice appeared large for some outcomes (eg, perceived need for imaging and perceived seriousness of the condition). TRIAL REGISTRATION:ACTRN12621001370897.

Background Complex Regional Pain Syndrome (CRPS) is a disabling pain disorder that is most common after a distal limb fracture. While the acute systemic immune response to the injury is thought to play a role in the development of CRPS, this hypothesis has never been tested directly. Thus, we evaluated whether elevated levels of circulating pro-inflammatory cytokines early after a fracture were associated with the development of CRPS. Methods We conducted a case-control study nested within a prospective cohort study. Individuals with wrist and/or hand fractures were recruited from specialist hand units. Baseline clinical data were obtained from participants within 28 days of fracture. CRPS status was determined 16 weeks after the fracture using a two-stage diagnostic process. Cytokine assays were obtained from all cases (defined using the Budapest criteria) and a random sample of those who did not have CRPS at 16 weeks. We calculated odds ratios with 95% confidence intervals to determine the risk of CRPS associated with the expression of each of 25 cytokines. Results Baseline data were collected for 702 consenting participants, of whom 535 provided blood samples. Follow-up at 16 weeks was 97.2%. 15 (2.2% of the cohort) met the Budapest CRPS criteria and 69 (including those who met the Budapest criteria; 9.8%) met the International Association for the Study of Pain (IASP) CRPS criteria. In all of the primary analyses (using Budapest criteria) and 49/50 secondary analyses (using IASP criteria), 95% confidence intervals for the association between cytokine levels and the risk of subsequently developing CRPS included the null value (OR = 1). However, the confidence intervals were wide. Conclusion There was no evidence that early post-injury expression of systemic cytokines was associated with a CRPS diagnosis 16 weeks after injury. This study does not provide support for the hypothesis that innate immune activation has a determinative role in the development of CRPS.

Background: Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality metaanalysis that outlines the clinical course of pain and function post-TKA. Methods: The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression. Results: In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.479.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively. Conclusion: Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function. (c) 2021 Elsevier Inc. All rights reserved.