Association between radiographic joint space narrowing, function, pain and muscle power in severe osteoarthritis of the knee

Estimation of patient-reported outcome measures based on features of knee joint muscle co-activation in advanced knee osteoarthritis

Electromyography (EMG) is considered a potential predictive tool for the severity of knee osteoarthritis (OA) symptoms and functional outcomes. Patient-reported outcome measures (PROMs), such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS), are used to determine the severity of knee OA. We aim to investigate muscle activation and co-contraction patterns through EMG from the lower extremity muscles of patients with advanced knee OA patients and evaluate the effectiveness of an interpretable machine-learning model to estimate the severity of knee OA according to the WOMAC (pain, stiffness, and physical function) and VAS using EMG gait features. To explore neuromuscular gait patterns with knee OA severity, EMG from rectus femoris, medial hamstring, tibialis anterior, and gastrocnemius muscles were recorded from 84 patients diagnosed with advanced knee OA during ground walking. Muscle activation patterns and co-activation indices were calculated over the gait cycle for pairs of medial and lateral muscles. We utilized machine-learning regression models to estimate the severity of knee OA symptoms according to the PROMs using muscle activity and co-contraction features. Additionally, we utilized the Shapley Additive Explanations (SHAP) to interpret the contribution of the EMG features to the regression model for estimation of knee OA severity according to WOMAC and VAS. Muscle activity and co-contraction patterns varied according to the functional limitations associated with knee OA severity according to VAS and WOMAC. The coefficient of determination of the cross-validated regression model is 0.85 for estimating WOMAC, 0.82 for pain, 0.85 for stiffness, and 0.85 for physical function, as well as VAS scores, utilizing the gait features. SHAP explanation revealed that greater co-contraction of lower extremity muscles during the weight acceptance and swing phases indicated more severe knee OA. The identified muscle co-activation patterns may be utilized as objective candidate outcomes to better understand the severity of knee OA.

Sit-to-stand power predicts functional performance and patient-reported outcomes in patients with advanced knee osteoarthritis. A cross-sectional study

BACKGROUND

Lower limb muscle power is positively associated with functional performance and patient-reported outcomes (PROMs) and suggested as an important variable to evaluate in patients with advanced knee osteoarthritis (OA).

OBJECTIVES

To explore the association between muscle power derived from the 30-sec sit-to-stand test (STS power) with functional performance and PROMs compared to maximal isometric knee extensor strength (KE MVC) in male- and female patients with advanced OA.

STUDY DESIGN

Cross-sectional design.

METHODS

Eighty-six patients (66.6 [64.9-67.7]years) with advanced knee OA were included. Dependent variables were STS power and KE MVC. Independent variables were Timed Up&Go (TUG), 40-m fast-paced walk test (40mFWT), Knee injury and Osteoarthritis Outcome Score (KOOS) subscales.

COVARIATE

Age.

ANALYSES

Simple linear- and multiple regression analyses with and without adjusting for age. Pitman's test was used to evaluate differences in correlation strength among dependent variables.

RESULTS

STS power demonstrated a statistical relationship with TUG and 40mFWT for both sexes (β coefficients -1.11 to -4.36 (p < 0.05), r2 = 0.47-0.55 (p < 0.05)), and with KOOS Pain, ADL, and Sport for male patients (β coefficients 6.53 to 7.17 (p < 0.05), r2 = 0.29-0.33 (p < 0.05)). Knee extensor MVC demonstrated no relationship with any outcomes for male patients or female patients. STS power displayed statistically stronger correlation to functional performance.

CONCLUSION

STS power was associated with functional performance in both male patients and female patients suffering from advanced knee OA. Moreover, STS power was associated with KOOS Pain, Sport, and ADLin male patients. The assessment of STS power should be considered in the evaluation of patients with advanced knee OA.

TRIAL REGISTRATION NUMBER

NCT04081493.

Association of patella alignment with cartilage relaxation times and self-reported symptoms in individuals with patellofemoral degeneration

To determine the cross-sectional and longitudinal associations of patella alignment with cartilage relaxation and patients' self-reported symptoms. Thirty participants with isolated patellofemoral joint (PFJ) degeneration (six males, 53.7 ± 9.3 years) and 24 controls (12 males, 47.6 ± 10.7 years) were included. Magnetic resonance assessment was performed to provide grading of structural abnormalities, cartilage relaxation times, and patella alignment. Self-reported symptoms were assessed using the self-administrated knee injury and osteoarthritis outcome score (KOOS). All participants were examined at baseline and 3 years. Statistical parametric mapping and Pearson partial correlation were used to evaluate the associations between patella alignment with cartilage relaxation times and self-reported symptoms, respectively. The analyses were performed between baseline (cross-sectional) as well as the baseline against 3 years (longitudinal). Results indicated that patella height and patella flexion were associated with T1ρ and T2 relaxation times at baseline (percentages of voxels showing significant correlation [PSV] = 10.1%-24.8%; mean correlations [R] = 0.34-0.36; mean p = 0.015-0.026). Furthermore, greater patella lateral alignment, lateral tilt, and lateral spin were associated with longer T2 times at 3 years (PSV = 11.0%-14.4%, R = 0.39-0.44, p = 0.017-0.028). Last, a higher patella was associated with a lower KOOS at baseline and at 3 years (R = -0.33 to -0.35). The study suggests that patella malalignment is a risk factor for worsening cartilage health, informing clinicians of a better rehabilitation program that targets PFJ degeneration.

Enhanced echo intensity in vastus medialis is associated with worsening of functional disabilities and symptoms in patients with knee osteoarthritis: a 3 years longitudinal study

Patients with knee osteoarthritis (OA) experience muscle quality loss, and is characterized by the enhanced echo intensity (EI) of the vastus medialis (VM) muscles and a high extracellular water-to-intracellular water (ECW/ICW) ratio of the thigh. This study aimed to elucidate the association between muscle degeneration and the worsening of functional disabilities and symptoms in patients with KOA over 3 years duration. Thirty-three patients with KOA who completed follow-up over 3 years were included in the analysis. The knee scoring system (KSS) was used to evaluate the functional abilities and symptoms. Based on the 3 years change in KSS scores, patients were classified into progressive or non-progressive groups. Muscle thickness (MT) and EI of the VM were determined using ultrasonography. The ECW/ICW ratio was measured using segmental-bioelectrical impedance spectroscopy. Multivariable logistic regression analyses were conducted with the groups as the dependent variables and VM-MT, VM-EI, and ECW/ICW ratio at baseline as independent variables, including potential confounders. Thirteen (39.4%) patients showed progressive features. VM-EI at baseline was significantly associated with the progression of functional disabilities (adjusted odds ratio [OR] 1.24; 95% confidence interval [CI] 1.03 − 1.50) and symptoms (adjusted OR 1.13; 95% CI 1.01 − 1.25). Enhanced VM-EI was associated with the worsening of functional disabilities and symptoms in patients with KOA over a period of 3 years. Therefore, the assessment of VM-EI using ultrasonography is a useful indicator for predicting the future worsening of KOA.

The use of intra-articular platelet rich plasma for the symptomatic management of osteoarthritis of the knee: a pilot study

BACKGROUND

Osteoarthritis of the knee is a chronic inflammatory condition resulting in significant patient disability, with intra-articular platelet rich plasma (PRP) injections having shown potential to improve symptomatic outcomes. This retrospective cohort pilot study aimed to observe whether PRP injections were beneficial in the symptomatic management of knee osteoarthritis in an Australian population, based on patient reported outcomes. An additional aim was to observe for an association between the number of injections and patient characteristics, such as body mass index, age, sex and radiologically determined severity of the disease.

METHODS

The cohort was drawn from those who attended Ballarat Orthopaedic and Sports Medicine for PRP injections and who had completed the appropriate pre- and post-injection Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire. WOMAC scores were analysed to observe for any difference following a course of PRP injections.

RESULTS

The data suggest that the use of PRP improved patient reported WOMAC scores. Additionally, it was shown that two injections had a greater effect than one injection, with a third injection providing no further benefit. Finally, there was an association with lower WOMAC scores post PRP therapy amongst male participants compared to female participants.

CONCLUSION

These results suggest two PRP injections are optimal for the symptomatic management of knee osteoarthritis, identifying a need for further prospective research in this Australian population.

Role of global femoral cartilage in assessing severity of primary knee osteoarthritis

Background/objective

Osteoarthritis is a degenerative joint disease marked by structural changes in the joint. Radiological evaluation can be used to assess structural changes. Pain, inflammation, and stiffness are common clinical symptoms, leading to limitations in daily activities. Ultrasound, unlike traditional radiography, allows for a direct examination of changes in soft tissues. In addition, it is sensitive in detecting osteophytes as well as identifying early OA changes in femoral cartilage associated with clinical manifestations and function.

Results

A cross- sectional study of 40 patients with primary KOA diagnosed according to the American College of Rheumatology (ACR) criteria. After radiographic evaluation using Kellgren-Lawrence (K-L) scale and US examination assessing global femoral hyaline cartilage (GFC), osteophytes, meniscal extrusion, effusion, and Baker’s cyst of the most symptomatic knee, there was significant correlation between (K-L) grading and (GFC) ultrasonographic grading (p = < 0.001). After assessment of pain and functional disability using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale, there was significant correlation between KL and GFC grading with age (p = < 0.001 for both), disease duration (p = < 0.001 for both) as well as WOMAC total scores (p = < 0.001 for both). GFC grading was the only independent predictor relative to other ultrasonographic variables for WOMAC total score (p = < 0.001).

Conclusions

US is a valid tool to evaluate knee joint space and is well correlated with radiographic images. KOA severity assessed by KL grading and GFC ultrasonographic grading showed good correlation with age, duration of the disease, pain intensity, and functional disability.

Functional characteristics of female patients based on ambulatory ability 1 year after total knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is commonly performed to reduce knee pain and improve physical function. Compared with the values for healthy, age-matched women, previous studies have reported large deficits in functional ability, such as muscle strength and ambulatory ability, in women 1 year post-TKA. Ambulatory ability is to move around, particularly by walking and is clinically assessed by the timed up and go test (TUG).

AIM

This study aimed to clarify the characteristics of knee functions in female patients whose ambulatory ability recovered to a normal level at 1 year after TKA.

METHODS

This cross-sectional study included 151 female patients who underwent TKA. The muscle strength of the lower extremity was measured, and the 2011 Knee Society Scoring (2011 KSS) system was used postoperatively. The TUG was conducted to assess ambulatory ability after TKA; then the patients were classified into the fast and slow ambulation groups based on previously reported gait-speed values of healthy female individuals. Then, we identified significant indicators of ambulatory ability at 1 year after TKA.

RESULTS

Forty-nine percent of patients after TKA achieved the level of ambulatory ability of a healthy female. Logistic regression analysis identified that the non-operative side knee extensor strength and the functional activity score, as assessed by the 2011 KSS, were variables significantly associated with the mid-term ambulatory ability after TKA.

CONCLUSION

Female patients with high non-operative knee extensor strength and a functional activity score at 1 year postoperatively can achieve better ambulatory ability than those of healthy, age-matched females.

Incidence of Total Knee Replacement in Patients With Previous Anterior Cruciate Ligament Reconstruction

OBJECTIVE

To determine the rate of total knee replacement (TKR) after anterior cruciate ligament reconstruction (ACL-R) compared to the general population.

DESIGN

Retrospective review.

SETTING

All hospitals that performed TKR and ACL-R in Manitoba between 1980 and 2015.

PARTICIPANT

All patients that underwent TKR and ACL-R in Manitoba between 1980 and 2015.

INTERVENTION

Patient factors gathered at time of surgery included: age, sex, urban or rural residence, neighborhood income quintile, and resource utilization band (RUB). Each person was matched with up to 5 people from the general population who had never had ACL-R and had not had a TKR at the time of the case ACL-R.

MAIN OUTCOME MEASURES

The rate of TKR after ACL-R.

RESULTS

Overall from 1980 to 2015, 8500 ACL-R were identified within the 16 to 60 years age group with a resultant 42 497 population matches. Sex was predominantly male. The mean age of the ACL-R group at the time of TKR was 53.7 years, whereas the mean age for the matched cohort was 58.2 years, P < 0.001. Those with ACL-R were 4.85 times more likely to go on to have TKR. Apart from age, no other risk factors examined (location, year of surgery, place of residence, income quintile, and RUB) seemed to increase risk of TKR after ACL-R.

CONCLUSION

Patients who underwent ACL-R were 5 times more likely to undergo TKR.

Muscle activity while ambulating on stairs and slopes: A comparison between individuals scheduled and not scheduled for knee arthroplasty and healthy controls

OBJECTIVE

To examine muscle activity patterns of the lower limbs while ascending and descending stairs and slope in adults with knee Osteoarthritis (knee-OA), who were scheduled or not scheduled for Total Knee Replacement (TKR) and healthy controls.

METHODS

This cross-sectional study included three groups: knee-OA subjects scheduled for TKR (TKR group; N = 15) and not scheduled for TKR (NTKR group; N = 15) and age-matched controls (N = 11). Outcome measures included: joint range of motion (ROM), Timed Up and Go (TUG), joint pain levels, and functional disability (Oxford) score. Also, durations of muscle activity (rectus femoris, semitendinosus, medial gastrocnemius, bilaterally, and soleus, and tibialis anterior of the OA limb) were recorded while the subjects ascended and descended stairs and a level surface.

RESULTS

Both knee-OA groups had significantly higher Oxford scores and bilateral knee pain levels compared to the control group. The TKR group had higher TUG score compared to the NTKR group. The activation duration of the Tibialis Anterior of the OA limb while ascending and descending stairs and slope were higher in the TKR group compared to the NTKR group. No differences in muscle activity durations were found when comparing the OA limb to contralateral limb.

CONCLUSION

The muscle activity strategies differentiated between individuals scheduled and not scheduled for TKR. The longer duration of muscle activity of Tibialis Anterior muscle in the TKR group compared to the NTKR group suggest that customized prehabilitation program is required for these groups.

Public Interest in Knee Pain and Knee Replacement during the SARS-CoV-2 Pandemic in Western Europe

Due to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, a large number of elective knee replacement procedures had to be postponed in both early and late 2020 in most western countries including Germany and the UK. It is unknown how public interest and demand for total knee arthroplasties was affected. Public interest in knee pain, knee osteoarthritis and knee arthroplasty in Germany and the UK was investigated using Google Trend Analysis. In addition, we monitored for changes in patient composition in our outpatient department. As of early March in Germany and of late March in the UK, until the lockdown measures, a 50 to 60% decrease in relative search frequency was observed in all categories investigated compared to the beginning of the year. While public interest for knee pain rapidly recovered, decreased interest for knee osteoarthritis and replacement lasted until the easing of measures. Shortly prior to and during the first lockdown mean search frequency for knee replacement was significantly decreased from 39.7% and 36.6 to 26.9% in Germany and from 47.7% and 50.9 to 23.7% in the UK (Germany: p = 0.022 prior to lockdown, p < 0.001 during lockdown; UK: p < 0.0001 prior to and during lockdown). In contrast, mean search frequencies did not differ significantly from each other for any of the investigated time frames during the second half of 2020 in both countries. Similarly, during the first lockdown, the proportion of patients presenting themselves to receive primary knee arthroplasty compared to patients that had already undergone knee replacement declined markedly from 64.7% to 46.9%. In contrast, patient composition changed only marginally during the lockdown measures in late 2020 in both Germany and the UK. We observed a high level of public interest in knee arthroplasty despite the ongoing pandemic. The absence of a lasting decline in interest in primary knee arthroplasty suggests that sufficient symptom reduction cannot be achieved without surgical care for a substantial number of patients.

Osteoarthritis year in review 2020: mechanics

The mechanical environment of the joint during dynamic activity plays a significant role in osteoarthritis processes. Understanding how the magnitude, pattern and duration of joint-specific loading features contribute to osteoarthritis progression and response to treatment is a topic of on-going relevance. This narrative review synthesizes evidence from recent papers that have contributed to knowledge related to three identified emerging subthemes: 1) the role of the joint mechanical environment in osteoarthritis pathogenesis, 2) joint biomechanics as an outcome to arthroplasty treatment of osteoarthritis, and 3) methodological trends for advancing our knowledge of the role of biomechanics in osteoarthritis. Rather than provide an exhaustive review of a broad area of research, we have focused on evidence this year related to these subthemes. New research this year has indicated significant interest in using biomechanics investigations to understand structural vs clinical progression of osteoarthritis, the role and interaction in the three-dimensional loading environment of the joint, and the contribution of muscle activation and forces to osteoarthritis progression. There is ongoing interest in understanding how patient variability with respect to gait biomechanics influences arthroplasty surgery outcomes, and subgroup analyses have provided evidence for the potential utility in tailored treatment approaches. Finally, we are seeing a growing trend in the application of translational biomechanics tools such as wearable inertial measurement units for improved integration of biomechanics into clinical decision-making and outcomes assessment for osteoarthritis.

Graphical-based multivariate analysis for knee joint clinical and kinematic data correlation assessment

A large amount of data including joint kinematics, joint kinetics, clinical and functional measurements constitutes the clinical gait analysis basis which is a process whereby quantitative gait information are collected to aid in clinical decision-making. Therefore, better understanding the relationship between the biomechanical and clinical data for the knee osteoarthritis (OA) patient is for a relevant importance. It's the purpose of this paper, which aims to analyze and visualize the correlation structure between biomechanical characteristics and clinical symptoms, and thus to provide an additional knowledge from the coupling of these parameters that will be useful for the pathology assessment of knee-joint disease in the end-staged knee OA patients. We perform two multivariate statistical approaches, first, a Canonical Correlation Analysis (CCA) to assess the multivariate association and, second, a graphical- based representation of the multivariate correlation to better understand the association between these multivariate data. Results show the usefulness of using such multivariate approaches to highlight association and specific correlation structure between the features and to extract meaningful information.

The Relationship Between Daily Physical Activity and Pain in Individuals with Knee Osteoarthritis

Objective

Investigate the association between physical activity and pain severity in individuals with knee osteoarthritis.

Design

Cross-sectional; systematic review with meta-analyses.

Methods

Thirty-one participants with knee osteoarthritis underwent assessment of symptoms via self-report questionnaires and quantitative sensory testing. Following testing, physical activity and symptoms were monitored for seven days using accelerometers and logbooks. Cross-correlation analyses were performed on fluctuations in symptoms and physical activity across the week to detect the relative timing of the strongest association between pain and activity. These data were complemented by meta-analyses of studies that examined correlations between pain from knee osteoarthritis and physical activity or fitness.

Results

Pain severity at baseline correlated with moderate to vigorous physical activity (r2 = 0.161–0.212, P &lt; 0.05), whereby participants who were more physically active had less pain. Conversely, the peak of the cross-correlation analyses was most often positive and lagging, which indicated that pain was increased subsequent to periods of increased activity. These superficially discrepant findings were supported by the results of a meta-analysis of 13 studies and 9,363 participants, which identified significant heterogeneity for associations between physical activity and pain (I2 = 91%). Stronger inverse associations were found between fitness and pain.

Conclusions

Associations between physical activity and pain in people with knee osteoarthritis are variable and dynamic. These results reflect the beneficial impact of an active lifestyle and accompanying higher fitness. Yet, the side effect of acute periods of physical activity to transiently exacerbate pain may influence the behavior of some people to avoid activity because of pain.

A Combined Visualization Method for Multivariate Data Analysis. Application to Knee Kinematic and Clinical Parameters Relationships

This paper aims to analyze the correlation structure between the kinematic and clinical parameters of an end-staged knee osteoarthritis population. The kinematic data are a set of characteristics derived from 3D knee kinematic patterns. The clinical parameters include the answers of a clinical questionnaire and the patient’s demographic characteristics. The proposed method performs, first, a regularized canonical correlation analysis (RCCA) to evaluate the multivariate relationship between the clinical and kinematic datasets, and second, a combined visualization method to better understand the relationships between these multivariate data. Results show the efficiency of using different and complementary visual representation tools to highlight hidden relationships and find insights in data.

Differences in Baseline Joint Moments and Muscle Activation Patterns Associated With Knee Osteoarthritis Progression When Defined Using a Clinical Versus a Structural Outcome

Both structural and clinical changes can signify knee osteoarthritis progression; however, these changes are not always concurrent. A better understanding of mechanical factors associated with progression and whether they differ for structural versus clinical outcomes could lead to improved conservative management. This study examined baseline gait differences between progression and no progression groups defined at an average of 7-year follow-up using 2 different outcomes indicative of knee osteoarthritis progression: radiographic medial joint space narrowing and total knee arthroplasty. Of 49 individuals with knee osteoarthritis who underwent baseline gait analysis, 32 progressed and 17 did not progress using the radiographic outcome, while 13 progressed and 36 did not progress using the arthroplasty outcome. Key knee moment and electromyography waveform features were extracted using principal component analysis, and confidence intervals were used to examine between-group differences in these metrics. Those who progressed using the arthroplasty outcome had prolonged rectus femoris and lateral hamstrings muscle activation compared with the no arthroplasty group. Those with radiographic progression had greater mid-stance internal knee rotation moments compared with the no radiographic progression group. These results provide preliminary evidence for the role of prolonged muscle activation in total knee arthroplasty, while radiographic changes may be related to loading magnitude.

Osteoarthritis and ACL Reconstruction-Myths and Risks

PURPOSE OF REVIEW

Anterior cruciate ligament (ACL) injury is one of the most common ligamentous injuries suffered by athletes participating in cutting sports. A common misperception is that ACL reconstruction can prevent osteoarthritis (OA). The goal of this paper is to review and discuss the contributing factors for the development of OA following ACL injury.

RECENT FINDINGS

There has been interesting new research related to ACL reconstruction. As understanding of knee biomechanics following ACL injury and reconstruction has changed over time, many surgeons have changed their surgical techniques to low anterior drilling to position their femoral tunnel in an attempt to place the ACL in a more anatomic position. Even with this change in the femoral tunnel position, 85% of knees following ACL reconstruction have abnormal tibial motion compared to contralateral non-injured knees. Studies have shown increases in inflammatory cytokines in the knee following ACL injury, and newer MRI sequences have allowed for earlier objective detection of degenerative changes to cartilage following injury. Recent studies have shown that injecting IL-1 receptor antagonist and corticosteroids can modulate the post-injury inflammatory cascade. ACL reconstruction does not prevent the development of OA but can improve knee kinematics and reduce secondary injury to the cartilage and meniscus. Advancements in imaging studies has allowed for earlier detection of degenerative changes in the knee, which has allowed researchers to study how new interventions can alter the course of degenerative change in the knee following ACL injury.

Factors influencing life-space mobility change after total knee arthroplasty in patients with severe knee osteoarthritis

[Purpose] The purpose of this study was to identify the factors influencing change in life-space mobility after total knee arthroplasty (TKA) in patients with severe knee osteoarthritis (knee OA). [Participants and Methods] Overall, 58 primary unilateral TKA recipients (9 males and 49 females; age ± SD 74.6 ± 6.5 years) were enrolled. We evaluated Life-Space Assessment (LSA) scores, knee extensor strength, Timed Up and Go test (TUG), one-leg standing time (OLS), Western Ontario and McMaster Universities osteoarthritis Index, and physical activity self-efficacy (SE) before surgery and at 3 months post-operation. [Results] Life space mobility significantly expanded 3 months after surgery compared with preoperative baseline. Preoperatively, walking SE and knee extensor muscle strength on the operative side were found to have strong correlation with LSA scores, while stairs SE and knee extensor muscle strength of the operative side were correlated at 3 months post-operation. [Conclusion] These findings suggest that to expand the life-space mobility of TKA recipients, it is important to enhance self-efficacy for general physical activity in addition to strengthening the quadriceps muscles.

Abnormal Joint Loading During Gait in Persons With Hip Osteoarthritis Is Associated With Symptoms and Cartilage Lesions

BACKGROUND

Hip joint loading in persons with hip osteoarthritis (OA) is not well studied, and its associations with symptoms and lesions are unknown.

OBJECTIVES

To determine whether hip joint loading differs between people with and without radiographic hip OA, and to identify its associations with patients' symptoms and cartilage morphology.

METHODS

Forty-eight patients (28 male; mean ± SD age, 56.0 ± 12.2 years) with hip OA and 95 controls (40 male; age, 43.2 ± 13.6 years) participated in this cross-sectional analysis. Pelvic radiographs, questionnaires, magnetic resonance imaging (MRI), and gait analysis were conducted. The Hip disability and Osteoarthritis Outcome Score (HOOS) was used to assess symptoms. Cartilage morphology was graded on MRI scans using the Scoring Hip Osteoarthritis with Magnetic Resonance Imaging (SHOMRI) system. Biomechanical variables included peak external hip joint moment (Newton meters per kilogram) and moment impulses (Newton meters times milliseconds per kilogram) in all planes. Generalized estimating equations were used to compare the biomechanical characteristics between groups. In the patients with OA, associations of moment impulses with HOOS and SHOMRI scores were assessed with partial correlations.

RESULTS

The OA group exhibited higher peak external hip flexion and adduction moments (P<.001) and higher hip flexion, adduction, and external rotation moment impulses (P = .001-.039). Increased hip flexion moment impulses were correlated with worse HOOS subscale scores (r = -0.361 to -0.424, P<.05) and worse femoral SHOMRI grades (ρ = 0.256-0.315, P<.05). Increased hip external rotation moment impulses were correlated with worse femoral SHOMRI grades (ρ = 0.283-0.372, P<.05).

CONCLUSION

Persons with hip OA exhibited abnormally high hip joint loads during walking, and high loads were associated with worse self-reported symptoms and cartilage morphology. J Orthop Sports Phys Ther 2019;49(12):917-924. Epub 14 Oct 2019. doi:10.2519/jospt.2019.8945.

Association Between Gait Kinetics and Symptomatic Progression in Persons With Patellofemoral With/Without Concurrent Tibiofemoral Osteoarthritis

To identify the biomechanical risk factors associated with symptomatic progression at 1-year follow-up in persons with patellofemoral joint (PFJ) osteoarthritis (OA). Patients' self-reported Knee Injury and Osteoarthritis Outcome Score questionnaires, magnetic resonance (MR) imaging, and three-dimensional gait analysis were obtained in 53 subjects with PFJ OA at baseline and after 1 year. Joint OA was diagnosed on knee MR images if cartilage lesions existed. Progression was defined by worsening of patients' self-reported symptoms from baseline to 1 year exceeding the minimal detectable change score. Analysis of covariance was used to compare peak knee flexion moment, knee flexion moment impulse, and vertical ground reaction force loading rate between progressors and non-progressors. Seven (13.2%) subjects exhibited progression in self-reported symptoms at 1-year follow-up. When comparing to non-progressors, significantly higher peak knee flexion moment during first half of stance (p = 0.017) and higher moment impulse during the both halves of stance were observed among progressors (p = 0.020-0.040). Persons with symptomatic PFJ OA progression with or without concurrent tibiofemoral OA exhibited abnormal joint loading mechanics when compared with individuals who did not progress. Further work is needed to determine if modification to these loading variables results in a change in the symptomatic progression in these individuals. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2593-2600, 2019.

Does surgery reduce knee osteoarthritis, meniscal injury and subsequent complications compared with non-surgery after ACL rupture with at least 10 years follow-up? A systematic review and meta-analysis

Objective

We compared long-term follow-up from surgical versus non-surgical treatment of ACL rupture regarding radiographic knee osteoarthritis (OA), secondary surgery, laxity and patient-reported outcome measures (PROMs).

Design

Systematic review and meta-analysis.

Data sources

Embase, MEDLINE, CINAHL and the Cochrane Library databases.

Eligibility criteria for selecting studies

Studies directly comparing the minimally invasive surgical (arthroscopy or miniarthrotomy) and non-surgical treatment of ACL rupture with at least 10 years of follow-up in adult patients were included.

Results

Five studies met the eligibility criteria. A meta-analysis revealed a higher risk of radiographic knee OA and a lower risk of secondary meniscal surgery for patients in the surgical group. The risk of graft rupture/secondary ACL revision and secondary ACL reconstruction was equal in the surgical and non-surgical groups. Knee laxity was lower among patients in the surgical group in four studies. No difference was found in the PROMs (ie, International Knee Documentation Committee, Tegner, Knee Injury and Osteoarthritis Outcome, and Lysholm scores).

Conclusion

The risk of radiographic knee OA was higher, but the risk of secondary meniscal injury was lower 10 years after surgical treatment of ACL rupture. The risk of graft rupture/secondary ACL revision or secondary reconstruction was unrelated to treatment type. The degree of knee laxity was reduced after surgical treatment in comparison with non-surgical treatment, while PROMs were similar. However, due to the methodological challenges highlighted in this systematic review, these findings must be interpreted with caution.

PROSPERO registration number

CRD42019119468

Relationship Between Strength Parameters and Functional Performance Tests in Patients With Severe Knee Osteoarthritis

BACKGROUND

Decreased leg muscle strength is a major determinant of reduced function in patients with knee osteoarthritis (OA). The identification of a strength parameter that is best correlated with functional performance is important for monitoring rehabilitation results.

OBJECTIVE

To determine which muscle strength measurements show the highest correlation with functional capacity in patients with severe knee OA shortly before total knee arthroplasty (TKA).

DESIGN

Cross-sectional exploratory study.

SETTING

Outpatient rehabilitation department at a university teaching hospital.

PATIENTS

The sample included 75 patients (51 female) scheduled for primary TKA, recruited through multistage sampling.

METHODS OR INTERVENTIONS

Independent variables were peak isometric, isokinetic concentric, and eccentric leg extensor strength measured on the leg press, as well as peak isometric knee extensor strength measured on the strength chair. Two multiple regression analyses were performed, one including all strength measures and the other including all of the strength ratios. Pearson correlation coefficients were calculated between the strength measures and functional test scores.

MAIN OUTCOME MEASUREMENTS

Dependent variables were the Timed Up and Go Test (TUG) and the Stair Test (ST).

RESULTS

The regression analysis including all strength measures could explain 11.9% of the variance of the TUG (P = .068, not significant [NS]) and 21.5% of the variance of the ST (P = .009, significant). The regression model for the strength ratios explained 11.8% of the variance of the TUG (P = .090, NS) and 6.3% of the ST (P = .217, NS).

CONCLUSIONS

Although univariate analysis confirmed significant correlations between strength measurements and functional tests, multiple regression analysis revealed a higher predictive value for the ST than for the TUG. The use of both muscle strength tests and performance-based function tests is advisable to evaluate functional impairments of patients with knee OA.

LEVEL OF EVIDENCE

III.

Influence of the severity of knee osteoarthritis on the association between leg muscle mass and quadriceps strength: the SPSS-OK study

Quadriceps strength is important for maintaining functional movement in patients with knee osteoarthritis (OA). We aimed to examine whether knee OA severity weakened the magnitude of the associations between leg muscle mass, quadriceps strength, and functional movement. Screening for People Suffering Sarcopenia in Orthopedic cohort of Kobe study (SPSS-OK) was a single-center cross-sectional study. We recruited 611 patients with knee OA. Leg muscle mass was determined by bioimpedance and used as a proxy for quadriceps muscle mass. Quadriceps strength and indices of functional movement (assessed by the functional activities category of the new Knee Society Score questionnaire [KSS] and the Timed Up and Go [TUG] test) were measured. Knee OA severity was determined by the Kellgren-Lawrence radiographic grade. A series of general linear models was fitted with adjustment for confounding variables. The increase in quadriceps strength per leg associated with a 1-kg increase in leg mass per leg was 7.29 Nm, 5.43 Nm, and 3.77 Nm among patients with knee OA grade 1/2, 3, and 4, respectively (P for interaction = 0.003). A 1-Nm increase in quadriceps strength per leg was associated with both a 0.14 point increase in KSS movement score and a 0.05 s decrease in TUG, regardless of knee OA severity (P for interaction 0.430 and 0.323). Severe knee OA may reduce efficiency in the exertion of quadriceps strength by leg muscle mass even when the amount of muscle mass remains unchanged.

Electromyographic activity of quadriceps muscle during sit-to-stand in patients with unilateral knee osteoarthritis

Objective

The sit-to-stand (STS) is a simple test to evaluate the functional performance of the quadriceps muscle in patients with knee osteoarthritis (OA). The aim was to evaluate the electromyographic (EMG) activity of the ipsilateral quadriceps during STS task at different seat heights and feet positions in patients with severe unilateral OA. The EMG activity was recorded in a group of eight participants with unilateral OA during the performance of STS task in four conditions: (1) knee-height seat with feet together, (2) knee-height seat with feet askew (feet side by side and heel-to-toe), (3) low-height seat (25% lower than knee-height seat) with feet together, and (4) low-height seat with feet askew.

Results

There was a statistically significant difference among the four conditions in the EMG activity (p =0.004). Particularly, the EMG activity of the quadriceps was significantly higher when participants rose from the low height with their feet askew than when they rose from the knee height with their feet placed together (p =0.004) or askew (p =0.002). These results recommend considering initial feet position and seat height when evaluating the functional activity of the quadriceps in patients with unilateral OA using STS test.

Effect of an orally formulated processed black cumin, from Iranian traditional medicine pharmacopoeia, in relieving symptoms of knee osteoarthritis: A prospective, randomized, double-blind and placebo-controlled clinical trial

AIM

Osteoarthritis is a global health problem, especially for the elderly. A good replacement for non-surgical treatments is the use of traditional medicines. We selected a revere plant (Nigella sativa L.), a widely utilized medicinal herb for the treatment of inflammatory conditions, from the Iranian traditional medicine (ITM) pharmacopoeia with proven anti-inflammatory and analgesic actions.

METHODS

We performed a prospective, randomized, double-blind, and placebo-controlled clinical trial, in order to investigate whether the herb is useful in alleviating the symptoms of knee osteoarthritis. American College of Rheumatology clinical criteria were the basis of diagnosis, while the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire was considered as the main outcome measure. One hundred and ten eligible patients were assigned to receive a placebo or an active intervention (2 g/day of processed N. sativa seed powder in divided doses). Acetaminophen tablets were the rescue medicine. Finally, 40 patients in the placebo group and 37 patients in the active group completed the trial and were included in the statistical analysis.

RESULTS

Both cohorts demonstrated statistically significant within-group differences (P < 0.05) in some subscales that were more prominent in the active group without any considerable adverse effects. Nevertheless, KOOS score results and the mean number of acetaminophen tablets used by patients showed no statistically significant between-group differences.

CONCLUSIONS

It can be concluded that future programmed studies with larger sample sizes, longer follow-up periods, and other forms of N. sativa seeds as an active intervention is necessary to evaluate its efficacy in relieving the symptoms of knee osteoarthritis.

The Influence of Knee Pain Location on Symptoms, Functional Status, and Knee-related Quality of Life in Older Adults With Chronic Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To evaluate whether knee pain location can influence symptoms, functional status, and knee-related quality of life in older adults with chronic knee pain.

MATERIALS AND METHODS

A total of 2959 painful knees from the Osteoarthritis Initiative database were analyzed. Trained interviewers recorded patient-reported location of knee pain. Painful knees were divided into 3 groups of patellofemoral only pain, tibiofemoral only pain, and combined pain. Self-reported knee-specific symptoms, functional status, and knee-related quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score.

RESULTS

The most common knee pain pattern was tibiofemoral only pain (62%), followed by patellofemoral only pain (23%), and combined pain (15%). The combined pain pattern was associated with greater odds of reporting pain, symptoms, sports, or recreational activity limitations and lower knee-related quality of life compared with either isolated knee pain patterns, after adjusting for demographics and radiographic disease severity. Individual item analysis further revealed that patients with combined pain had greater odds of reporting difficulty with daily weight-bearing activities that required knee bending compared with tibiofemoral or patellofemoral only pain patterns. Furthermore, symptoms, functional status, and knee-related quality of life were comparable between patients with patellofemoral and tibiofemoral only pain patterns, after adjusting for demographics and radiographic disease severity.

DISCUSSION

Combined patellofemoral and tibiofemoral pain is associated with poorer clinical presentation compared with isolated knee pain from either location. In addition, patellofemoral pain in isolation may be as important as tibiofemoral pain in causing symptoms and functional limitation in older adults with chronic knee pain.

Analysis of the connection between pain, disability and a radiological image determining the treatment process

Introduction: The objective of this paper is to analyse the correlation between pain and the degree of disability, and the lesions shown on radiological examination of KOA.

Material and method: The study encompassed 31 female patients (42 knees) aged 51-70 years, with diagnosed idiopathic knee osteoarthritis. Medical history and analysis of previously performed x-ray scans were conducted. The history included questions regarding pain (VAS, WOMAC index) and the maximum marching distance, the presence of oedema and instability as well as disability in everyday life (WOMAC index). The radiological lesions were assessed using the Kellgren and Lawrence Grading Scale. Moreover, the widths of the joint spaces were measured.

Results: The patients’ pain in everyday activities (WOMAC) showed a positive correlation with the presence of osteophytes (r=0.32), and the intensity of the pain on the VAS correlated with the presence of joint osteophytes (r=0.46) and with the elevation of the intercondylar eminence (r=0.32). The other disorders on the x-ray image did not correlate with the pain. Positive correlations were identified between the presence of oedema (r=0.57) and instability (r=0.39), and the presence of lesions in the patellofemoral joint. The patients’ disability in everyday activities (WOMAC) showed a negative correlation with the width of the joint spaces (r<-0.34). However, no correlations were observed between the remaining x-ray lesions and the WOMAC index.

Conclusions: Only a small number of subjects showed a correlation indicating an interdependency between the painful sensations and the degree of disability versus the progression of radiographic lesions. Among the KOA risk factors, it is worth noting the presence of obesity which, in these studies, affected more than half of the female patients.

MRI findings associated with development of incident knee pain over 48 months: data from the osteoarthritis initiative

PURPOSE

The purpose of this nested case-control study was to identify baseline, incident, and progressive MRI findings visible on standard MRI clinical sequences that were associated with development of incident knee pain in subjects at risk for OA over a period of 48 months.

METHODS

We analyzed 60 case knees developing incident pain (WOMAC(pain) = 0 at baseline and WOMAC(pain) ≥ 5 at 48 months) and 60 control knees (WOMAC(pain) = 0 at baseline and WOMAC(pain) = 0 at 48 months) from the Osteoarthritis Initiative. 3 T knee MRIs were analyzed using a modified WORMS score (cartilage, meniscus, bone marrow) at baseline and after 48 months. Baseline and longitudinal findings were grouped into logistic regression models and compared using likelihood-ratio tests. For each model that was significant, a stepwise elimination was used to isolate significant MRI findings.

RESULTS

One baseline MRI finding and three findings that changed from baseline to 48 months were associated with the development of pain: at baseline, the severity of a cartilage lesion in the medial tibia was associated with incident pain--(odds ratio (OR) for incident pain = 3.05; P = 0.030). Longitudinally, an incident effusion (OR = 9.78; P = 0.005), a progressive cartilage lesion of the patella (OR = 4.59; P = 0.009), and an incident medial meniscus tear (OR = 4.91; P = 0.028) were associated with the development of pain.

CONCLUSIONS

Our results demonstrate that baseline abnormalities of the medial tibia cartilage as well as an incident joint effusion, progressive patella cartilage defects, and an incident medial meniscus tear over 48 months may be associated with incident knee pain. Clinically, this study helps identify MRI findings that are associated with the development of knee pain.

Improvement following total knee replacement surgery: Exploring preoperative symptoms and change in preoperative symptoms

OBJECTIVE

To determine whether changes in preoperative osteoarthritis (OA) symptoms are associated with improvement after total knee replacement (TKR) and to identify predictors of clinically significant improvement.

METHODS

Data on Osteoarthritis Initiative participants who were annually assessed and underwent TKR were included. T0 was the assessment prior to TKR while T-1 was the assessment prior to that. T+2 was the second assessment after TKR. We compiled data on the Western Ontario and McMaster Universities OA Index (WOMAC), OA-related symptoms, and radiographic severity. We defined clinically significant improvement as improvement in WOMAC total score ≥ to the minimal important difference (MID) (0.5 SD of mean change) between T0 and T+2 and also considered other definitions of improvement. Logistic regression models were performed to evaluate the relationship between improvement and preoperative measures.

RESULTS

Improved (n = 211) compared to unimproved (n = 58) patients had greater worsening of their WOMAC pain (p = 0.002) and disability (p < 0.001) from T-1 to T0. Preoperative measures as predictors of improvement included higher WOMAC disability (OR = 1.08, p < 0.001), presence of chronic OA symptoms in the surgical knee (OR = 5.77, p = 0.033), absence of OA-related symptoms in the contralateral knee (OR = 9.25, p < 0.001), exposure to frequent knee bending (OR = 3.46, p = 0.040), and having a Kellgren-Lawrence x-ray grade of ≥2 in the contralateral knee (OR = 4.71, p = 0.010).

CONCLUSIONS

More than 75% of participants had improvement after TKR. Improved patients were more likely to have escalation of OA pain and disability prior to surgery than unimproved patients. Other preoperative measures predicted improvement after TKR.

Three-dimensional biomechanical gait characteristics at baseline are associated with progression to total knee arthroplasty

Objective

To determine if baseline 3-dimensional (3-D) biomechanical gait patterns differed between those patients with moderate knee osteoarthritis (OA) who progressed to total knee arthroplasty (TKA) and those that did not, and whether these differences had predictive value.

Methods

Fifty-four patients with knee OA had ground reaction forces and segment motions collected during gait. 3-D hip, knee, and ankle angles and moments were calculated over the gait cycle. Amplitude and temporal waveform characteristics were determined using principal component analysis. At followup 5–8 years later, 26 patients reported undergoing TKA. Unpaired t-tests were performed on baseline demographic and waveform characteristics between TKA and no-TKA groups. Receiver operating curve analysis, stepwise discriminate analysis, and logistic regression analysis determined the combination of features that best classified TKA and no-TKA groups and their predictive ability.

Results

Baseline demographic, symptomatic, and radiographic variables were similar, but 7 gait variables differed (P < 0.05) between groups. A multivariate model including overall knee adduction moment magnitude, knee flexion/extension moment difference, and stance–dorsiflexion moment had a 74% correct classification rate, with no overtraining based on cross-validation. A 1-unit increase in model score increased by 6-fold the odds of progression to TKA.

Conclusion

In addition to the link between higher overall knee adduction magnitude and future TKA, an outcome of clear clinical importance, novel findings include altered sagittal plane moment patterns indicative of reduced ability to unload the joint during midstance. This combination of dynamic biomechanical factors had a 6-fold increased odds of future TKA; adding baseline demographic and clinical factors did not improve the model.

Medial abrasion syndrome: a neglected cause of knee pain in middle and old age

Knee pain is a prevailing health problem of middle and old age. Medial plica-related medial abrasion syndrome (MAS), although a well-known cause of knee pain in younger individuals, has rarely been investigated in older individuals. This prospective study was conducted to investigate the prevalence and clinical manifestations of this syndrome as a cause of knee pain in middle and old age. The outcomes of arthroscopic treatment for this syndrome were also evaluated.A total of 232 knees of 169 patients >40 years of age (41-82, median: 63 years old) suffering from chronic knee pain were analyzed. The clinical diagnosis, predisposing factors, presenting symptoms, and physical signs were investigated. The sensitivity and specificity of each parameter of the clinical presentation for the diagnosis of MAS were evaluated after confirmation by arthroscopy. For patients with MAS, the roentgenographic and arthroscopic manifestations were investigated, and arthroscopic medial release (AMR) was performed. The outcomes were evaluated by the changes in the pain domain of the Knee Society scoring system and by patient satisfaction. The prevalence of medial plica was 95%, and osteoarthritis (OA) was the most common clinical diagnosis. Symptoms of pain and crepitus in motion and local tenderness during physical examination were the most sensitive parameters for the diagnosis. A history of a single knee injury combined with local tenderness and a palpable band found during physical examination were the most specific parameters for the diagnosis. The majority of patients suffering from this syndrome were successfully treated using AMR, yielding a satisfaction rate of 85.5% after a minimum of 3 years.MAS is a common cause of knee pain in middle and old age and can be effectively treated by AMR. Its concomitance with OA warrants further investigation.

Hidden osteophyte formation on plain X-ray is the predictive factor for development of knee osteoarthritis after 48 months--data from the Osteoarthritis Initiative

OBJECTIVE

To examine whether the detection of osteophytes anywhere in the knee could serve as a pre-radiographic biomarker for osteoarthritis (OA) development.

METHODS

Baseline magnetic resonance imaging (MRIs) of 132 participants in the Osteoarthritis Initiative (OAI) were studied. Based on radiographs, 66 knees were assessed as osteoarthritis-free (no-osteoarthritis [NOA], or Kellgren/Lawrence [K/L] severity grade 0/1 both at baseline and 48 months), and another 66 knees were assessed as having radiographic OA changes (pre-radiographic osteoarthritis [PROA], or with K/L grade 0/1 at baseline and grade ≥ 2 at 48 months). Using baseline MRI data, we examined eight sites of osteophyte formation: the medial and lateral femoral condyle (MFC and LFC, respectively); medial and lateral tibial plateau (MTP and LTP, respectively); medial and lateral facets of the patellofemoral joint (PM and PL, respectively); tibial spine (TS); and femoral intercondylar notch (IC). Knee joint osteophyte size was assessed via the 8-point marginal osteophytes item of the whole-organ magnetic resonance imaging score (WORMS). The frequencies and distributions of osteophytes were compared between groups.

RESULTS

Mild-size osteophytes (defined as score ≥ 2) were observed more frequently at the MFC (P = 0.00278), MTP (P = 0.0046), TS (P = 0.0146), PM (P < 0.0001), PL (P = 0.0012), and IC (P < 0.0001) in PROA knees than in NOA knees. Moderate-size osteophytes (defined as score ≥ 4) were more frequently observed in PROA knees than in NOA knees only at the IC (P < 0.0001).

CONCLUSION

Knees with osteophyte formation at the IC, even those of K/L severity grade 0/1, are at risk for the development of radiographic OA by 48 months.

A review of the relationship between leg power and selected chronic disease in older adults

OBJECTIVE

This review investigates the relationship between leg muscle power and the chronic conditions of osteoarthritis, diabetes mellitus, and cardiovascular disease among older adults. Current literature assessing the impact of chronic disease on leg power has not yet been comprehensively characterized. Importantly, individuals with these conditions have shown improved leg power with training.

METHODS

A search was performed using PubMed to identify original studies published in English from January 1998 to August 2013. Leg power studies, among older adults ≥ 50 years of age, which assessed associations with osteoarthritis, diabetes mellitus, and/or cardiovascular disease were selected. Studies concerning post-surgery rehabilitation, case studies, and articles that did not measure primary results were excluded.

RESULTS

Sixteen studies met inclusion criteria, addressing osteoarthritis (n=5), diabetes mellitus (n=5), and cardiovascular disease (n=6). Studies generally supported associations of lower leg power among older adults with chronic disease, although small sample sizes, cross-sectional data, homogenous populations, varied disease definitions, and inconsistent leg power methods limited conclusions.

CONCLUSIONS

Studies suggest that osteoarthritis, diabetes mellitus, and cardiovascular disease are associated with lower leg power compared to older adults without these conditions. These studies are limited, however, by the heterogeneity in study populations and a lack of standardized measurements of leg power. Future larger studies of more diverse older adults with well-defined chronic disease using standard measures of leg power and interventions to improve leg power in these older adults with chronic disease are needed.

A stiff price to pay: does joint stiffness predict disability in an older population?

OBJECTIVES

To describe the prevalence of joint stiffness and associated comorbidities in community-living older adults and to determine whether joint stiffness, independent of pain, contributes to new and worsening disability.

DESIGN

Population-based cohort.

SETTING

Urban and suburban communities in the Boston, Massachusetts, area.

PARTICIPANTS

Adults aged 70 and older (N = 765) underwent a baseline home interview and clinic examination, 680 participants completed the 18-month follow-up.

MEASUREMENTS

Morning joint stiffness on most days in the past month was assessed in the arms, back, hips, and knees. Mobility limitations were measured using self-reported difficulty and the Short Physical Performance Battery (SPPB). The home interview and clinic examination included extensive health measures.

RESULTS

Four hundred one participants reported morning joint stiffness, half of these with one site of stiffness and the other half with multisite stiffness. Twenty percent of participants with multisite stiffness and 50% with single site stiffness did not have a major stiffness-associated condition. After adjustment for pain severity and other covariates, multisite stiffness was associated with a 64% greater risk of developing new or worsening mobility difficulty (relative risk = 1.64, 95% confidence interval = 1.05-2.79). Those with multisite stiffness had declined more quickly in physical performance over the 18-month follow up.

CONCLUSION

Older adults with multisite stiffness are more likely to be at risk of disability than those without joint stiffness after accounting for pain severity and the presence of stiffness-associated conditions. Better assessment, along with strategies to prevent and treat multisite joint stiffness is needed to prevent or slow the progression of disability in elderly adults.

Osteoarthritis disease progression model using six year follow-up data from the osteoarthritis initiative

The objective was to develop a quantitative model of disease progression of knee osteoarthritis over 6 years using the total WOMAC score from patients enrolled into the Osteoarthritis Initiative (OAI) study. The analysis was performed using data from the Osteoarthritis Initiative database. The time course of the total WOMAC score of patients enrolled into the progression cohort was characterized using non-linear mixed effect modeling in NONMEM. The effect of covariates on the status of the disease and the progression rate was investigated. The final model provided a good description of the experimental data using a linear progression model with a common baseline (19 units of the total WOMAC score). The WOMAC score decreased by 1.77 units/year in 89% of the population or increased by 1.74 units/year in 11% of the population. Multiple covariates were found to affect the baseline and the rate of progression, including BMI, sex, race, the use of pain medications, and the limitation in activity due to symptoms. A mathematical model to describe the disease progression of osteoarthritis in the studied population was developed. The model identified two sub-populations with increasing or decreasing total WOMAC score over time, and the effect of important covariates was quantified.

Knee extensor and flexor muscle power explains stair ascension time in patients with unilateral late-stage knee osteoarthritis: a cross-sectional study

OBJECTIVES

To determine the extent of asymmetrical deficits in knee extensor and flexor muscles, and to examine whether asymmetrical muscle deficits are associated with mobility limitations in persons with late-stage knee osteoarthritis (OA).

DESIGN

Cross-sectional.

SETTING

Research laboratory.

PARTICIPANTS

A clinical sample (N=56; age range, 50-75y) of eligible persons with late-stage knee OA awaiting knee replacement.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Knee extensor and flexor power and torque assessed isokinetically; thigh muscle cross-sectional area (CSA) assessed by computed tomography; mobility limitation assessed by walking speed and stair ascension time; and pain assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire.

RESULTS

The asymmetrical deficits in knee extensor and flexor power and torque were between 18% and 29% (P<.001). Regarding the thigh muscle CSA, the asymmetrical deficit was 4% (P<.001). Larger asymmetrical knee extensor power deficits and weaker knee extensor and flexor power on the contralateral side were associated with slower stair ascension times. Moreover, weaker knee extensor and flexor power on the ipsilateral side were associated with slower stair ascension times. Greater knee pain in the OA joint was independently associated with slower stair ascending time in both models.

CONCLUSIONS

The knee extensor and flexor muscle power of both the ipsilateral and contralateral sides and the pain in the OA knee were independently associated with stair ascension times. These results highlight the importance of assessing muscle power on both sides and knee pain in the prevention of mobility limitations in patients with knee OA.

Correlates of foot pain severity in adults with hallux valgus: a cross-sectional study

Background

Hallux valgus (HV) is highly prevalent and associated with progressive first metatarsophalangeal joint subluxation and osteoarthritis. The link between structural HV deformity and foot pain is unclear. This study investigated possible explanatory factors surrounding foot pain in HV, including radiographic HV angle and signs of joint degeneration.

Methods

Participants were 60 adults (53 female) with HV aged 20 to 75 years. Participant demographics and a range of radiographic, clinical and functional measures were considered potential correlates of foot pain. Self-reported foot pain (visual analogue scales and a dichotomous definition) was considered the dependent variable. Multivariate modelling was used to determine which characteristics and measures explained pain, with univariate analyses first used to screen potential variables.

Results

Approximately 20 to 30% of the variance in foot pain associated with HV could be explained by patient characteristics such as poorer general health status, lower educational attainment and increased occupational physical activity levels, in combination with some dynamic physical characteristics such as hallux plantarflexion weakness and reduced force-time integral under the second metatarsal during gait. Neither increasing lateral deviation of the hallux (HV angle) nor presence of first metatarsophalangeal joint osteoarthritis was associated with foot pain.

Conclusions

This study shows that passive structural factors, including HV angle, do not appear to be significant correlates of foot pain intensity in HV. Our data demonstrate the importance of considering patient characteristics such as general health and physical activity levels when assessing foot pain associated with HV.

Correlation of WOMAC and KOOS scores to tibiofemoral cartilage loss on plain radiography and 3 Tesla MRI: data from the osteoarthritis initiative

PURPOSE

The purpose of this study was to determine the correlation between the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) and Knee Injury Osteoarthritis Outcomes scores (KOOS) and the degree of tibiofemoral cartilage loss on plain radiography and 3T magnetic resonance imaging (MRI). We hypothesize that these subjective outcome scores will have a significant correlation to quantitative joint space loss.

METHODS

Data used in the preparation of this article were obtained from the osteoarthritis initiative (OAI) database (OAI public use data sets kMRI_QCart_Eckstein18 and kXR_QJSW_Duryea16). Four hundred and forty-five patients had WOMAC/KOOS scores, quantitative tibiofemoral joints space width on plain radiographs and quantitative tibiofemoral cartilage thickness and per cent full thickness cartilage loss on 3T MRI. Joint space width on plain radiographs was correlated to cartilage thickness on MRI, and WOMAC/KOOS scores were correlated to the degree of cartilage loss using Pearson correlation coefficients.

RESULTS

There was a statistically significant correlation between medial and lateral compartment cartilage thickness on MRI and medial and lateral joint space width on plain radiography (r = 0.86, r = 0.80) (p < 0.001). KOOS knee pain score was significantly correlated to increasing per cent full thickness cartilage loss in the medial femoral compartment (r = 0.34) (p < 0.001). KOOS symptom score was significantly correlated to decreasing joint space width in the medial (r = 0.16) and lateral (r = 0.15) compartment and increasing per cent full thickness cartilage loss in the medial femoral compartment (r = 0.36) (p < 0.001). No WOMAC score was correlated to degree of joint space width, cartilage thickness or per cent full thickness cartilage loss (n.s).

CONCLUSION

The WOMAC and KOOS scores are poor indicators of tibiofemoral cartilage loss, with only the KOOS symptom and knee pain score being weakly correlated. Osteoarthritis is a multifactorial process and the need to treat patients based off their symptoms and rely on radiographs as confirmatory modalities, and not diagnostic modalities, when talking about OA and medical intervention.

Outcomes of total knee arthroplasty in relation to preoperative patient-reported and radiographic measures: data from the osteoarthritis initiative

INTRODUCTION

Total knee arthroplasty (TKA) is the preferred surgical treatment for end-stage osteoarthritis. However, substantial numbers of patients still experience poor outcomes. Consequently, it is important to identify which patient characteristics are predictive of outcomes in order to guide clinical decisions. Our hypothesis is that preoperative patient-reported outcome measures and radiographic measures may help to predict TKA outcomes.

METHODS

Using cohort data from the Osteoarthritis Initiative, we studied 172 patients who underwent TKA. For each patient, we compiled pre- and postoperative Western Ontario and McMaster University Arthritis Index (WOMAC) scores. Radiographs were measured for knee joint angles, femorotibial angles, anatomical lateral distal femoral angles, and anatomical medial proximal tibial angles; Kellgren and Lawrence (KL) grades were assigned to each compartment of the knee. All studied measurements were compared to WOMAC outcomes.

RESULTS

Preoperative WOMAC disability, pain, and total scores were positively associated with postoperative WOMAC total scores (P = .010, P = .010, and P = .009, respectively) and were associated with improvement in WOMAC total scores (P < .001, P < .001, and P < .001, respectively). For radiographic measurements, preoperative joint angles were positively associated with improvements in postoperative WOMAC total scores (P = .044). Combined KL grades (medial and lateral compartments) were negatively correlated with postoperative WOMAC disability and pain scores (P = .045 and P = .044) and were positively correlated with improvements in WOMAC total scores (P = .001).

CONCLUSIONS

All preoperative WOMAC scores demonstrated positive associations with postoperative WOMAC scores, while among the preoperative radiographic measurements only combined KL grades and joint angles showed any correlation with postoperative WOMAC scores. Higher preoperative KL grades and joint angles were associated with better (lower) postoperative WOMAC scores, demonstrating an inverse correlation.

Vitamin D deficiency associates with γ-tocopherol and quadriceps weakness but not inflammatory cytokines in subjects with knee osteoarthritis

Knee osteoarthritis (OA) is a degenerative joint condition and a leading cause of physical disability in the United States. Quadriceps weakness and inflammatory cytokines contribute to the pathogenesis of knee OA, and both of which, increase with vitamin D deficiency. Other micronutrients, such as vitamins C and E and β-carotene, modulate inflammatory cytokines and decrease during inflammation. The purpose of this study was to test the hypothesis that vitamin D deficiency associates with quadriceps weakness, an increase in serum cytokines, and a decrease in circulating micronutrients in subjects with knee OA. Subjects (age, 48±1 y; serum 25(OH)D, 25.8±1.1 ng/mL) with knee OA were categorized as vitamin D deficient (n=17; serum 25(OH)D≤20 ng/mL), insufficient (n=21; serum 25(OH)D 20–29 ng/mL), or sufficient (n=18; serum 25(OH)D≥30 ng/mL). Single-leg strength (concentric knee extension–flexion contraction cycles at 60 °/s) and blood cytokine, carotene (α and β), ascorbic acid, and tocopherol (α and γ) concentrations were measured. Quadriceps peak torque, average power, total work, and deceleration were significantly (all p<0.05) impaired with vitamin D deficiency. Serum γ-tocopherol concentrations were significantly (p<0.05) increased with vitamin D deficiency. In the vitamin D sufficient group, γ-tocopherol inversely correlated (r=−0.47, p<0.05) with TNF-α, suggesting a pro-inflammatory increase with a γ-tocopherol decrease despite a sufficient serum 25(OH)D concentration. We conclude that vitamin D deficiency is detrimental to quadriceps function, and in subjects with vitamin D sufficiency, γ-tocopherol could have an important anti-inflammatory role in a pathophysiological condition mediated by inflammation.

•

We investigated the vitamin D association with mediators of knee osteoarthritis.

•

Vitamin D deficiency associated with quadriceps dysfunction.

•

Vitamin D deficiency was not associated with serum cytokines.

•

Vitamin D deficiency associated with increased plasma γ-tocopherol concentrations.

•

γ-Tocopherol inversely correlated with TNF-α in vitamin D sufficient subjects.

The relationship between radiological severity and functional status in patients with knee osteoarthritis

In this study, we aimed to explore the relationship between radiological findings and functional status in patients with knee osteoarthritis (OA). In this study, 117 female patients diagnosed with knee osteoarthritis according to the ACR criteria were included. Antero-posterior knee radiographs of the patients were graded according to Kellgren-Lawrence, and functional capacity was evaluated with WOMAC and Lequesne indexes. Quadriceps and hamstring muscle strengths were also concentrically measured using an isokinetic dynamometer, five repetitions at 90°/s and 20 repetitions at 180°/s. In this study, a significant relationship was determined between the age, weight, praying period, and pain period of the patients with the radiological findings. No significant relationship was determined between the functional capacity of knee and muscle strength and the radiological findings. However, left hamstring functioning capacity was found as lower in the group with the radiological findings. The radiological findings in knee OA are not associated with decrease in knee muscle strength and functional capacity. Clinical symptoms such as pain, decrease in range of motion, etc. in knee OA may be responsible for decrease in knee muscle strength and functional capacity.

Effects of self-reported osteoarthritis on physical performance: a longitudinal study with a 10-year follow-up

BACKGROUND AND AIMS

Osteoarthritis (OA) of the knee or hip is associated with limitations in activities of daily life. There are only a few long-term studies on how knee or hip OA affects the course of physical performance. The aim of this study was to investigate the effects of knee or hip OA on physical performance during a follow-up period of 10 years.

METHODS

Participants in the Longitudinal Aging Study Amsterdam with self-reported hip or knee OA (N = 155) were prospectively followed for 10 years on 4 occasions from the onset of OA and compared to participants without OA (N = 1004). Physical performance was tested with walk, chair stand and balance tests. Scores for each test were summed to a total performance score (range 0-12), higher scores indicating better performance. Generalized estimating equations were used to analyze differences between participants with and without OA, unadjusted as well as adjusted for confounders.

RESULTS

There was a significant interaction between OA and sex (P = 0.068). Both in men and women, total performance was lower for participants with OA, with greater differences in men. Chair stand and walking performance (P < 0.05), but not balance, were lower in participants with OA. After adjustment for confounders, these associations remained significant in men but not in women. Additional analyses correcting for follow-up duration and attrition showed lower performance scores for men and women with OA.

CONCLUSIONS

OA negatively affected physical performance 3-6 years after it was first reported. Performance in men with OA was more affected than in women.

The effect of depressive symptoms on the association between radiographic osteoarthritis and knee pain: a cross-sectional study

BACKGROUND

The progressive nature of knee osteoarthritis (OA) leads to not only to physical but also to psychosocial decline; this aspect can influence knee pain experience, manifestations and inevitably diagnostic accuracy.

METHODS

Data on 663 subjects was obtained by interview using a structured questionnaire on social, demographic, behavioural and clinical data. Painful knee was assessed regarding having pain: ever, in the last year, in the last 6 months and in the last month. Using factor analysis, participants were graded using a knee pain score, with higher scores representing more symptomatology. Depressive symptoms were evaluated with the Beck Depressive Inventory (BDI), and radiographic knee OA was classified using the Kellgren Lawrence (KL) scale; those with KL ≥ 2 were considered as having radiographic OA.

RESULTS

Knee pain was reported by 53.2% of those with radiographic KL ≥ 2 and by 33.2% of those with radiographic KL < 2. The prevalence of depressive symptoms (BDI > 14) was 19.9% among participants with radiographic KL ≥ 2 and 12.6% among those with radiographic KL < 2 (p = 0.01). The association of knee pain with radiographic knee OA was higher in higher pain scores and in participants without depressive symptoms. Among participants with BDI ≤ 14 the likelihood ratio to identify patients with radiographic knee OA increased with increased pain scores: 1.02 for score 1; 2.19 for score 2 and 7.34 when participants responded positively to all pain questions (score 3). Among participants with depressive symptoms (BDI > 14) likelihood ratios were 0.51, 1.92, 1.82, respectively. The results were similar for both genders.

CONCLUSIONS

Knee pain scores increased ability to identify participants with radiographic KL ≥ 2 in both sexes. However, the presence of depressive symptoms impairs the ability of knee pain complaints to identify patients with radiographic OA.