Systematic symptom management in the IMPACT Consortium: rationale and design for 3 effectiveness-implementation trials.

Cancer and its treatment produce deleterious symptoms across the phases of care. Poorly controlled symptoms negatively affect quality of life and result in increased health-care needs and hospitalization. The Improving the Management of symPtoms during And following Cancer Treatment (IMPACT) Consortium was created to develop 3 large-scale, systematic symptom management systems, deployed through electronic health record platforms, and to test them in pragmatic, randomized, hybrid effectiveness and implementation trials. Here, we describe the IMPACT Consortium's conceptual framework, its organizational components, and plans for evaluation. The study designs and lessons learned are highlighted in the context of disruptions related to the COVID-19 pandemic.

Implementation and evaluation of an expanded electronic health record-integrated bilingual electronic symptom management program across a multi-site Comprehensive Cancer Center: The NU IMPACT protocol.

BACKGROUND: People with cancer experience symptoms that adversely affect quality of life. Despite existing interventions and clinical guidelines, timely symptom management remains uneven in oncology care. We describe a study to implement and evaluate an electronic health record (EHR)-integrated symptom monitoring and management program in adult outpatient cancer care. METHODS: Our cancer patient-reported outcomes (cPRO) symptom monitoring and management program is a customized EHR-integrated installation. We will implement cPRO across all Northwestern Memorial HealthCare (NMHC) hematology/oncology clinics. We will conduct a cluster randomized modified stepped-wedge trial to evaluate patient and clinician engagement with cPRO. Further, we will embed a patient-level randomized clinical trial to evaluate the impact of an additional enhanced care (EC; cPRO plus web-based symptom self-management intervention) relative to usual care (UC; cPRO alone). The project uses a Type 2 hybrid effectiveness-implementation approach. The intervention will be implemented across seven regional clusters within the healthcare system comprising 32 clinic sites. A 6-month prospective pre-implementation enrollment period will be followed by a post-implementation enrollment period, during which newly enrolled, consenting patients will be randomly assigned (1:1) to EC or UC. We will follow patients for 12 months post-enrollment. Patients randomized to EC will receive evidence-based symptom-management content on cancer-related concerns and approaches to enhance quality of life, using a web-based tool ("MyNM Care Corner"). This design allows for within- and between-site evaluation of implementation plus a group-based comparison to demonstrate effectiveness on patient-level outcomes. DISCUSSION: The project has potential to guide implementation of future healthcare system-level cancer symptom management programs. http://ClinicalTrials.gov # NCT03988543.

Tracking dynamic changes in implementation strategies over time within a hybrid type 2 trial of an electronic patient-reported oncology symptom and needs monitoring program.

Background: Longitudinal tracking of implementation strategies is critical in accurately reporting when and why they are used, for promoting rigor and reproducibility in implementation research, and could facilitate generalizable knowledge if similar methods are used across research projects. This article focuses on tracking dynamic changes in the use of implementation strategies over time within a hybrid type 2 effectiveness-implementation trial of an evidence-based electronic patient-reported oncology symptom assessment for cancer patient-reported outcomes in a single large healthcare system. Methods: The Longitudinal Implementation Strategies Tracking System (LISTS), a timeline follow-back procedure for documenting strategy use and modifications, was applied to the multiyear study. The research team used observation, study records, and reports from implementers to complete LISTS in an electronic data entry system. Types of modifications and reasons were categorized. Determinants associated with each strategy were collected as a justification for strategy use and a potential explanation for strategy modifications. Results: Thirty-four discrete implementation strategies were used and at least one strategy was used from each of the nine strategy categories from the Expert Recommendations for Implementing Change (ERIC) taxonomy. Most of the strategies were introduced, used, and continued or discontinued according to a prospective implementation plan. Relatedly, a small number of strategies were introduced, the majority unplanned, because of the changing healthcare landscape, or to address an emergent barrier. Despite changing implementation context, there were relatively few modifications to the way strategies were enacted, such as a change in the actor, action, or dose. Few differences were noted between the trial's three regional units under investigation. Conclusion: This study occurred within the ambulatory oncology clinics of a large, academic medical center and was supported by the Quality team of the health system to ensure greater uptake, uniformity, and implementation within established practice change processes. The centralized nature of the implementation likely contributed to the relatively low proportion of modified strategies and the high degree of uniformity across regions. These results demonstrate the potential of LISTS in gathering the level of data needed to understand the impact of the many implementation strategies used to support adoption and delivery of a multilevel innovation. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT04014751, identifier: NCT04014751.

Symptom and needs assessment screening in oncology patients: Alternate outreach methods during COVID-19.

Patients with cancer are ideally screened for symptoms, including distress, using patient-reported outcome measures (PROMs). This initiative was developed to ensure patients without access to an electronic portal were screened for distress and related symptoms during the COVID-19 pandemic. Prior to the pandemic, these patients could complete screening in clinic. However, many visits transitioned to telehealth. We implemented a standardized telephone outreach process targeting patients without active electronic portal accounts to improve remote symptom monitoring. Outreach resulted in 172 completed screens, identifying 110 needs for 63 individuals. Twenty-eight patients completed patient portal enrollment. Outreach calls captured a higher percentage of Black patients (34%) and a higher percentage of 61-80 year olds (69%) compared to portal users. Telephone outreach during the pandemic captured data that otherwise would have been missed in elderly and minority patients without electronic patient portal access. Patient engagement is vital to the distress screening process.

Procedure coding in the American Joint Replacement Registry.

In October 2015, the Centers for Medicare & Medicaid Services transitioned from the 9th version of the International Classification of Diseases (ICD-9) codes for reporting patient diagnosis and medical procedures to the 10th version (ICD-10). The multitude of coding options for total joint arthroplasty in ICD-10-procedural coding (ICD-10-PCS) poses some challenges for the American Joint Replacement Registry (AJRR) in identifying precise procedures being reported. While AJRR participating hospitals are familiar with ICD-10-PCS, this new coding may not have been introduced to most AJRR participating surgeons. To address these issues, AJRR initiated an ICD-10 workgroup to define and map appropriate ICD-10 codes to total joint procedure types. This initiative sought to improve accuracy of AJRR data.

Infection burden in total hip and knee arthroplasties: an international registry-based perspective.

BACKGROUND: Infection remains a leading cause of failure of hip and knee replacements. Infection burden is the ratio of implants revised for infection to the total number of arthroplasties in a specific period, measuring the steady state of infection in a registry. We hypothesized infection burden would be similar among arthroplasty registries. METHODS: We evaluated publicly reported data from 6 arthroplasty registries (Australian Orthopaedic Association National Joint Replacement Registry [AOANJRR], New Zealand Joint Registry, Swedish Hip Arthroplasty Register, Swedish Knee Arthroplasty Register, National Joint Registry of England, Wales, Northern Ireland, and the Isle of Man, and the American Joint Replacement Registry) for revisions performed with an infection diagnosis over the last 6 years. RESULTS: The 2015 hip infection burden varied between registries from 0.76% (AOANJRR) to 1.24% (Swedish Hip Arthroplasty Register), and the unweighted overall average for hip infection burden was 0.97%. In 2012, 2013, and 2014, average hip infection burden held steady at 0.87%, 0.93%, and 0.94%, respectively, higher than the preceding 2 years. The 2015 knee infection burden varied from 0.88% (AOANJRR) to 1.28% (Swedish Knee Arthroplasty Register), and the unweighted average was 1.03%. In 2012, 2013, and 2014, knee infection burden was 1.04%, 1.11%, and 1.02%, respectively. These numbers were also higher than the preceding 2 years. CONCLUSIONS: Infection burden may be one measure of the overall success in registry populations as well as monitoring the steady state of infection worldwide. Despite global efforts to reduce postoperative infection, infection burden has actually increased in the selected registries over time.

Knee confidence as it relates to physical function outcome in persons with or at high risk of knee osteoarthritis in the osteoarthritis initiative.

OBJECTIVE: To evaluate whether low knee confidence at baseline is associated with poor baseline-to-3-year physical function outcome in the Osteoarthritis Initiative. METHODS: Knee confidence was assessed using an item from the Knee Injury and Osteoarthritis Outcome Score instrument. Physical function was assessed using self-report measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] function score and Short Form 12 physical component scale) and performance-based measures (20-meter walk and chair stand test). Poor function outcome was defined as moving into a worse function group or remaining in the 2 worst function groups between baseline and 3 years. Logistic regression was used to evaluate the relationship between baseline knee confidence level and poor baseline-to-3-year function outcome, adjusting for potential confounders. RESULTS: The sample included 3,975 men and women with or at high risk of developing osteoarthritis of the knee, of whom 37-53% had poor baseline-to-3-year function outcome. For both self-report measures, increasingly worse knee confidence was associated with a greater risk of poor function outcome, and trend tests supported a graded response (e.g., the adjusted odds ratios [95% confidence intervals] for the WOMAC function score for worsening confidence categories were 1.26 [1.07-1.49], 1.43 [1.16-1.77], and 2.05 [1.49-2.82], P for trend <0.0001). Similar associations between confidence and performance-based function outcome were observed, but statistical significance did not persist in adjusted analyses. Factors independently associated with poor function outcome for all 4 outcome measures were depressive symptoms, comorbidity, body mass index, and joint space narrowing. CONCLUSION: These findings indicate that worse knee confidence at baseline is independently associated with greater risk of poor function outcome by self-report measures, with evidence of a graded response; the relationship with performance measures is not significant in fully adjusted models.

Varus-valgus alignment: reduced risk of subsequent cartilage loss in the less loaded compartment.

OBJECTIVE: Varus-valgus alignment has been linked to subsequent progression of osteoarthritis (OA) within the mechanically stressed (medial for varus, lateral for valgus) tibiofemoral compartment. Cartilage data from the off-loaded compartment are sparse. The purpose of this study was to examine our hypotheses that neutral and valgus (versus varus) knees each have reduced odds of cartilage loss in the medial subregions and that neutral and varus (versus valgus) knees each have reduced odds of cartilage loss in the lateral subregions. METHODS: Patients with knee OA underwent knee magnetic resonance imaging at baseline and 2 years. The mean cartilage thickness was quantified within 5 tibial and 3 femoral subregions. We used logistic regression with generalized estimating equations to analyze the relationship between baseline alignment and subregional cartilage loss at 2 years, adjusting for age, sex, body mass index, and disease severity. RESULTS: A reduced risk of cartilage loss in the medial subregions was associated with neutral (versus varus) alignment (external tibial, central femoral, external femoral) and with valgus (versus varus) alignment (central tibial, external tibial, central femoral, external femoral). A reduced risk of cartilage loss in the lateral subregions was associated with neutral (versus valgus) alignment (central tibial, internal tibial, posterior tibial) and with varus (versus valgus) alignment (central tibial, external tibial, posterior tibial, external femoral). CONCLUSION: Neutral and valgus alignment were each associated with a reduction in the risk of subsequent cartilage loss in certain medial subregions and neutral and varus alignment with a reduction in the risk of cartilage loss in certain lateral subregions. These results support load redistribution as an in vivo mechanism of the long-term alignment effects on cartilage loss in knee OA.

Subregional effects of meniscal tears on cartilage loss over 2 years in knee osteoarthritis.

OBJECTIVES: Meniscal tears have been linked to knee osteoarthritis progression, presumably by impaired load attenuation. How meniscal tears affect osteoarthritis is unclear; subregional examination may help to elucidate whether the impact is local. This study examined the association between a tear within a specific meniscal segment and subsequent 2-year cartilage loss in subregions that the torn segment overlies. METHODS: Participants with knee osteoarthritis underwent bilateral knee MRI at baseline and 2 years. Mean cartilage thickness within each subregion was quantified. Logistic regression with generalised estimating equations were used to analyse the relationship between baseline meniscal tear in each segment and baseline to 2-year cartilage loss in each subregion, adjusting for age, gender, body mass index, tear in the other two segments and extrusion. RESULTS: 261 knees were studied in 159 individuals. Medial meniscal body tear was associated with cartilage loss in external subregions and in central and anterior tibial subregions, and posterior horn tear specifically with posterior tibial subregion loss; these relationships were independent of tears in the other segments and persisted in tibial subregions after adjustment for extrusion. Lateral meniscal body and posterior horn tear were also associated with cartilage loss in underlying subregions but not after adjustment for extrusion. Cartilage loss in the internal subregions, not covered by the menisci, was not associated with meniscal tear in any segment. CONCLUSION: These results suggest that the detrimental effect of meniscal tears is not spatially uniform across the tibial and femoral cartilage surfaces and that some of the effect is experienced locally.

Within-subregion relationship between bone marrow lesions and subsequent cartilage loss in knee osteoarthritis.

OBJECTIVE: Bone marrow lesions are believed to increase risk of knee osteoarthritis (OA) progression. Whether their effect is local and whether it can be explained by other types of bone lesions concomitantly present in the same subregion is unclear. We evaluated bone lesion frequency in subregions without cartilage lesions and cartilage lesion frequency in subregions without bone lesions, and investigated the within-subregion bone marrow lesion/subsequent cartilage loss relationship after adjusting for other types of bone lesions at baseline. METHODS: Individuals with knee OA had magnetic resonance imaging at baseline and 2 years later. Cartilage integrity and bone marrow lesions, cysts, and attrition were scored within tibiofemoral subregions. Logistic regression, with generalized estimating equations to account for correlation among multiple subregions within a knee, was used to estimate odds ratios (ORs) for cartilage loss associated with bone marrow lesions, adjusting for age, sex, body mass index, and bone attrition and cysts in the same subregion. RESULTS: Analyzing 1,953 subregions among 177 knees, 90% of subregions had no bone lesions at baseline. Only 0-3% of subregions without cartilage lesions had bone lesions in the same subregion; in contrast, 5-33% of subregions without bone lesions had cartilage lesions. Bone marrow lesions at baseline were associated with cartilage loss in the same subregion at 2 years, adjusting for other types of bone lesions at baseline (adjusted OR 3.74, 95% confidence interval 1.59-8.82). CONCLUSION: In subjects with knee OA, bone marrow lesions were rare at early disease stages but predicted subregional cartilage loss after accounting for the presence of other types of bone lesions in the same subregion.

Medial-to-lateral ratio of tibiofemoral subchondral bone area is adapted to alignment and mechanical load.

Malalignment is known to affect the medial-to-lateral load distribution in the tibiofemoral joint. In this longitudinal study, we test the hypothesis that subchondral bone surface areas functionally adapt to the load distribution in malaligned knees. Alignment (hip-knee-ankle angle) was measured from full limb films in 174 participants with knee osteoarthritis. Coronal magnetic resonance images were acquired at baseline and 26.6 +/- 5.4 months later. The subchondral bone surface area of the weight-bearing tibiofemoral cartilages was segmented, with readers blinded to the order of acquisition. The size of the subchondral bone surface areas was computed after triangulation by proprietary software. The hip-knee-ankle angle showed a significant correlation with the tibial (r (2) = 0.25, P < 0.0001) and femoral (r (2) = 0.07, P < 0.001) ratio of medial-to-lateral subchondral bone surface area. In the tibia, the ratio was significantly different between varus (1.28:1), neutral (1.18:1), and valgus (1.13:1) knees (analysis of variance [ANOVA]; P < 0.00001). Similar observations were made in the weight-bearing femur (0.94:1 in neutral, 0.97.1 in varus, 0.91:1 in valgus knees; ANOVA P = 0.018). The annualized longitudinal increase in subchondral bone surface area was significant (P < 0.05) in the medial tibia (+0.13%), medial femur (+0.26%), and lateral tibia (+0.19%). In the medial femur, the change between baseline and follow-up was significantly different (ANOVA; P = 0.020) between neutral, varus, and valgus knees, with the increase in surface area being significantly greater (P = 0.019) in varus than in neutral knees. Tibiofemoral subchondral bone surface areas are shown to be functionally adapted to the medial-to-lateral load distribution. The longitudinal findings indicate that this adaptational process may continue to take place at advanced age.

Patterns of femorotibial cartilage loss in knees with neutral, varus, and valgus alignment.

OBJECTIVE: Malalignment is known to alter medial-to-lateral femorotibial load distribution and to affect osteoarthritis (OA) progression in the mechanically stressed compartment. We investigated the pattern of cartilage loss in neutral, varus, and valgus knees. METHODS: Alignment was measured from full-limb radiographs in 174 participants with symptomatic knee OA. Coronal magnetic resonance images were acquired at baseline and a mean +/- SD of 26.6 +/- 5.4 months later. The weight-bearing femorotibial cartilages were segmented from paired images. Cartilage volume, surface area, and thickness were determined in total cartilage plates and defined subregions using proprietary software. RESULTS: The medial-to-lateral ratio of femorotibial cartilage loss was 1.4:1 in neutral knees (n = 74), 3.7:1 in varus knees (n = 57), and 1:6.0 in valgus knees (n = 43). The relative contribution of cartilage thickness change tended to be greater in knees with mild cartilage loss, whereas the increase of denuded area was greater in knees with accelerated cartilage loss. In both varus and neutral knees, the greatest changes were observed in the same subregions of the medial femorotibial compartment (central and external medial tibia, and central medial femur). In valgus and neutral knees, the subregions with the greatest changes in the lateral femorotibial compartment were also similar (internal and central lateral tibia, external lateral femur). CONCLUSION: The medial-to-lateral rate of femorotibial cartilage loss strongly depended on alignment. Subregions of greater-than-average cartilage loss within the stressed compartment were, however, similar in neutral, varus, and valgus knees. This indicates that the medial-to-lateral loading pattern is different, but that the (sub)regional loading pattern may not differ substantially between neutral and malaligned knees.

Relationship of meniscal damage, meniscal extrusion, malalignment, and joint laxity to subsequent cartilage loss in osteoarthritic knees.

OBJECTIVE: Progressive knee osteoarthritis (OA) is believed to result from local factors acting in a systemic environment. Previous studies have not examined these factors concomitantly or compared quantitative and qualitative cartilage loss outcomes. The aim of this study was to test whether meniscal damage, meniscal extrusion, malalignment, and laxity each predicted tibiofemoral cartilage loss after controlling for the other factors. METHODS: Laxity and alignment were measured at baseline in individuals with knee OA. Magnetic resonance imaging included spin-echo coronal and sagittal imaging for meniscal scoring and axial and coronal spoiled gradient echo sequences with water excitation for cartilage quantification. Tibial and weight-bearing femoral condylar subchondral bone area and cartilage surface were segmented. Cartilage volume, denuded bone area, and cartilage thickness were quantified in each plate, with progression defined as cartilage loss >2 times the coefficient of variation for each plate. Qualitative outcome was assessed as worsening of the cartilage score. Logistic regression analysis with generalized estimating equations yielded odds ratios for each factor, adjusting for age, sex, body mass index, and the other factors. RESULTS: We studied 251 knees in 153 persons. After full adjustment, medial meniscal damage predicted medial tibial cartilage volume loss and tibial and femoral denuded bone increase, while varus malalignment predicted medial tibial cartilage volume and thickness loss and tibial and femoral denuded bone increase. Lateral meniscal damage predicted every lateral outcome. Laxity and meniscal extrusion had inconsistent effects. After full adjustment, no factor except medial laxity predicted qualitative outcome. CONCLUSION: Using quantitative cartilage loss assessment, local factors that independently predicted tibial and femoral loss included medial meniscal damage and varus malalignment (medially) and lateral meniscal damage (laterally). A measurement of quantitative outcome was more sensitive at revealing these relationships than a qualitative approach.

Full-limb and knee radiography assessments of varus-valgus alignment and their relationship to osteoarthritis disease features by magnetic resonance imaging.

OBJECTIVE: To examine the correlation between hip-knee-ankle and femur-tibia radiograph angles, calculate the offset of the femur-tibia angle with respect to the hip-knee-ankle angle, calculate the sensitivity and specificity and area under the receiver operating characteristic (ROC) curve of the femur-tibia angle, and examine the relationship of malalignment by each approach with osteoarthritis (OA) tissue pathology in the mechanically stressed compartment using magnetic resonance imaging (MRI). METHODS: Individuals with knee OA underwent full-limb and knee radiographs and knee MRI. Linear regression was used to determine if the 2 angles differed systematically and to identify the cutoff. Alignment means for MRI grades were compared using Dunnett's t-test. RESULTS: In the 146 participants (109 women, mean age 70 years, body mass index 30.6 kg/m(2)), femur-tibia and hip-knee-ankle angles correlated (r = 0.86; 95% confidence interval [95% CI] 0.81, 0.90). On average, the femur-tibia angle was 3.4 degrees more valgus (3.0 degrees in women and 4.7 degrees in men); after correction, its sensitivity and specificity (to predict the hip-knee-ankle angle) were 0.84 and 0.84 for identifying varus and 0.98 and 0.73 for valgus, respectively. The area under the ROC curve (95% CI) was 0.91 (0.86, 0.96) for varus and 0.94 (0.89, 0.99) for valgus. Varus severity worsened comparably with each alignment measure as medial lesion score on MRI worsened. Laterally, as lesion score worsened, comparably worse valgus was seen with either assessment approach. CONCLUSION: In knee OA, the knee radiograph femur-tibia and full-limb radiograph hip-knee-ankle angles were correlated. The femur-tibia angle, corrected for mean offset, was sensitive, specific, and had excellent discriminative ability for identifying varus and valgus alignment evidenced by area under the ROC curve. The relationship between alignment and specific OA MRI features was comparable with the 2 approaches. Use of the femur-tibia angle, corrected for offset, should be considered in research and clinical settings.

The relationship between toe-out angle during gait and progression of medial tibiofemoral osteoarthritis.

BACKGROUND: A greater knee adduction moment increases risk of medial tibiofemoral osteoarthritis (OA) progression. Greater toe-out during gait shifts the ground reaction force vector closer to the centre of the knee, reducing the adduction moment. The present study was designed to test whether greater toe-out is associated with lower likelihood of medial OA progression. METHODS: Baseline assessments included: kinematic/kinetic gait parameters using an optoelectronic camera system, force platform and inverse dynamics to calculate three-dimensional external knee moments; toe-out angle (formed by the line connecting heel strike and toe-off plantar surface centres of pressure and the forward progression line; knee pain; and full-limb alignment. Knee x-rays (semi-flexed) were obtained at baseline and at 18 months, with progression noted as medial joint space grade worsening. With logistic regression, odds ratios (ORs) for progression/5 degrees toe-out were estimated. RESULTS: In the 56 subjects (59% women, mean age 66.6 years, body mass index (BMI) 29), baseline toe-out angle was less in knees with than without progression (difference -4.4, 95% CI -8.5 to -0.3). Greater toe-out was associated with reduced likelihood of progression (OR 0.60, 95% CI 0.37 to 0.98). Adjusting for age, gender, BMI, pain severity and disease severity, the OR was 0.62, 95% CI 0.36 to 1.06. Adjusting for adduction moment (second peak), the OR was 0.72, 95% CI 0.40 to 1.28. CONCLUSIONS: Osteoarthritic knees that progressed had less toeing-out than knees without progression. Greater toe-out was associated with a lower likelihood of progression. Adjustment for covariates did not alter the OR, although the 95% CI included 1. Further adjustment for adduction moment did alter the OR, consistent with the possibility that a mechanism of the effect may be via lowering of the adduction moment.

Hip abduction moment and protection against medial tibiofemoral osteoarthritis progression.

OBJECTIVE: To test the hypothesis that a greater peak internal hip abduction moment is associated with a reduced likelihood of ipsilateral medial tibiofemoral osteoarthritis (OA) progression. METHODS: Fifty-seven persons with knee OA (by definite osteophyte presence and symptoms) were evaluated. Baseline assessments included kinematic and kinetic gait parameters, obtained with an optoelectronic camera system and force platform, with inverse dynamics used to calculate 3-dimensional moments at the joints; pain, using a separate visual analog scale for each knee; and alignment, using full-limb radiographs. Radiographs of the knee in a semiflexed position, with fluoroscopic confirmation of tibial rim alignment, were obtained at baseline and 18 months later. Disease progression was defined as worsening of the grade of medial joint space narrowing. Logistic regression obtained with generalized estimating equations was used to estimate odds ratios (ORs) for progression per unit of hip abduction moment, after excluding knees with the worst joint space grade at baseline (which could not progress). RESULTS: The 57 participants (63% women) with mild to moderate OA had a mean age of 67 years and a mean body mass index of 29. A greater internal hip abduction moment during gait was associated with a reduced likelihood of medial tibiofemoral OA progression, with OR/unit hip abduction moment of 0.52 and a 95% confidence interval (95% CI) of 0.32-0.85. This protective effect persisted after adjustment for age, sex, walking speed, knee pain severity, physical activity, varus malalignment severity, hip OA presence, and hip OA symptom presence, with an adjusted OR of 0.43 a 95% CI of 0.22-0.81. CONCLUSION: A greater hip abduction moment during gait at baseline protected against ipsilateral medial OA progression from baseline to 18 months. The likelihood of medial tibiofemoral OA progression was reduced 50% per 1 unit of hip abduction moment.

The natural history of anteroposterior laxity and its role in knee osteoarthritis progression.

OBJECTIVE: To test the hypotheses that 1) osteoarthritic (OA) knees at more advanced stages have less anteroposterior (AP) laxity compared with OA knees at milder stages, 2) AP laxity decreases over time, and 3) the absence of a decrease in AP laxity is associated with greater progression of medial tibiofemoral OA. METHODS: The study group comprised 230 patients with knee OA (75% women, mean age 64 years, mean body mass index [BMI] 30 kg/m(2)). At baseline and 18 months, AP laxity was measured (in millimeters of tibial translation, under AP shear loading), and semiflexed AP knee radiographs (with knee position confirmed by fluoroscopy) were obtained. Osteophytes were graded for each compartment, using a scale of 0-4. Disease progression was measured as the amount of medial joint space loss between baseline and followup, using linear regression with generalized estimating equations. RESULTS: At baseline, measurements of AP laxity were lower in knees with a Kellgren/Lawrence (K/L) score of 4 (mean +/- SD 5.0 +/- 2.1 mm) than in those with a K/L score of 0-1 (mean +/- SD 7.1 +/- 2.6 mm). There was a weak negative correlation between osteophyte grade and AP laxity. In knees with a K/L score of 0-2, AP laxity was slightly lower at 18 months than at baseline. AP laxity at baseline was not a predictor of progression of OA. Knees without a decrease in AP laxity had a greater loss of medial joint space (0.22 mm greater, after adjusting for age, sex, and BMI) than did knees in which laxity decreased. CONCLUSION: AP laxity at baseline is not predictive of progression of OA. Although knees with a K/L score of 4 had less AP laxity than those with a K/L score of 0-1, most of this difference was attributable to the significant difference in AP laxity between knees with a K/L score of 0-1 and knees with a K/L score of 2 (i.e., definite osteophytes). Knees in which AP laxity decreased had less medial joint space loss than did knees without a decrease in AP laxity. The knee joint may successfully compensate for AP laxity; the absence of such compensation may have a deleterious effect.

Thrust during ambulation and the progression of knee osteoarthritis.

OBJECTIVE: To determine whether the presence of varus thrust at baseline increases the risk of progression of medial tibiofemoral osteoarthritis (OA), whether knees with thrust have a greater adduction moment, whether thrust has any additional impact on top of static varus, and whether thrust is associated with poor physical function outcome. METHODS: Two hundred thirty-seven patients with knee OA (definite osteophytes and symptoms) underwent baseline gait observation to assess varus thrust and full-limb radiography to assess alignment. Sixty-four of these 237 patients also underwent quantitative gait analysis to determine the maximum knee adduction moment. Two hundred thirty patients (97%) returned for followup at 18 months. At baseline and 18 months, the 230 participants had semiflexed, fluoroscopically confirmed knee radiographs (with progression defined as worsening of medial joint space grade); self-reported and performance-based measures of function were also assessed. Logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) for medial OA progression, after excluding knees that were not at risk for progression. RESULTS: Varus thrust was present in 67 of 401 knees. Thrust increased 4-fold (age-, sex-, body mass index-, and pain-adjusted OR 3.96, 95% confidence interval [95% CI] 2.11-7.43) the odds of medial progression, with some reduction after further adjustment for varus alignment severity. In varus-aligned knees, thrust increased the odds of OA progression 3-fold (adjusted OR 3.17, 95% CI 1.60-6.31). In the gait substudy, the adduction moment was greater in knees with a thrust compared with knees without a thrust. Having a thrust in both knees versus neither knee was associated with a 2-fold increase in the OR for poor physical function outcome (P not significant). CONCLUSION: Varus thrust is a potent risk factor, identifiable by simple gait observation, for disease progression in the medial compartment, the most common site of OA involvement at the knee. Varus thrust may also predict poor physical function outcome. Varus thrust increased the odds of progression among varus-aligned knees considered separately, suggesting that knees with a thrust are a subset of varus-aligned knees at particularly high risk for progression of OA.

Varus-valgus alignment in the progression of patellofemoral osteoarthritis.

OBJECTIVE: To test the hypotheses that lateral patellofemoral (PF) osteoarthritis (OA) progression is more common than medial PF OA progression, that varus alignment increases the likelihood of medial PF OA progression, and that valgus alignment increases the likelihood of lateral PF OA progression. METHODS: Patients with knee OA were recruited from the community. Inclusion criteria were definite osteophyte presence (i.e., Kellgren/Lawrence radiographic grade >/=2) in 1 or both knees and at least some difficulty with knee-requiring activity. Varus-valgus alignment (the angle formed by the intersection of the mechanical axes of the femur and tibia) was measured on a full-limb radiograph at baseline. To assess PF OA progression, weight-bearing skyline views of the PF compartment were obtained at baseline and at 18-month followup. Knees with the highest grade of PF narrowing at baseline were excluded from analysis. Logistic regression and generalized estimating equations were used; odds ratios (ORs) were adjusted for age, sex, and body mass index. RESULTS: Lateral PF OA progression, which occurred in 120 (30%) of 397 knees, was more common than was medial PF OA progression, which occurred in 60 knees (15%). Varus (versus nonvarus) alignment increased the odds of PF OA progression isolated to the medial PF compartment (adjusted OR 1.85, 95% confidence interval [95% CI] 1.00-3.44). Valgus alignment increased the odds of PF OA progression isolated to the lateral compartment (adjusted OR 1.64, 95% CI 1.01-2.66). CONCLUSION: Lateral PF OA progression was more common than medial progression, and varus-valgus alignment influenced the likelihood of PF OA progression in a compartment-specific manner. Interventions that address the stress imposed by alignment on the PF compartments may delay PF OA progression and should be developed.

Physical functioning over three years in knee osteoarthritis: role of psychosocial, local mechanical, and neuromuscular factors.

OBJECTIVE: To identify factors that predict a poor physical function outcome over 3 years in individuals with knee osteoarthritis (OA), in an effort to aid in the development of strategies to prevent such functional limitations and consequential disability. METHODS: Community-recruited individuals with knee OA underwent baseline, 18-month, and 3-year assessments of candidate risk factors and physical function. Risk factors were age, body mass index (BMI), knee pain intensity (on a visual analog scale [VAS]), local mechanical and neuromuscular factors (varus-valgus laxity, malalignment, proprioceptive inaccuracy, quadriceps strength, hamstring strength), activity level (Physical Activity Scale for the Elderly, amount of aerobic exercise), and psychosocial factors (Short-Form 36 [SF-36] mental health and role-functioning emotional subscales, self-efficacy using the Arthritis Self-Efficacy Scale physical function subscale, and social support using the Medical Outcomes Study Social Support Survey). Outcome was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function scale and rate of chair-stand performance. Participants were grouped by quintile of baseline WOMAC score. The baseline to 3-year outcome was considered "good" when function improved by 1 or more quintiles or remained within the 2 highest function groups, and was considered "poor" when function declined by 1 or more quintiles or remained within the 3 lowest function groups. The same approach was taken for chair-stand outcome. Logistic regression was used to evaluate both the baseline level and the baseline to 18-month change in each factor as a predictor of physical function outcome over 3 years, adjusting for age, BMI, knee pain intensity, disease severity, and additional potential confounders. RESULTS: Factors that significantly increased the likelihood of a poor WOMAC outcome were baseline laxity (crude odds ratio [OR] 1.48/3 degrees, 95% confidence interval [95% CI] 1.02-2.14), BMI (OR 1.26/5 units, 95% CI 1.01-1.57), knee pain intensity (OR 1.21/20 mm on VAS, 95% CI 1.00-1.47), and baseline to 18-month increase in knee pain (OR 1.32/20 mm on VAS, 95% CI 1.06-1.65). Factors that significantly protected against a poor WOMAC outcome were better baseline mental health (OR 0.62/5 points, 95% CI 0.44-0.87), self-efficacy (OR 0.79/5 points, 95% CI 0.67-0.93), and social support (OR 0.86/10 points, 95% CI 0.75-0.98), and greater amount of aerobic exercise (OR 0.75/60 minutes each week, 95% CI 0.63-0.89). Factors that increased the likelihood for a poor function outcome by the chair-stand performance rate were age and proprioceptive inaccuracy, and factors that reduced the likelihood for poor chair-stand outcome were strength (attenuated after adjusting for pain intensity or self-efficacy), self-efficacy, and aerobic exercise. Individuals who sustained high function and those who sustained low function over the 3 years were described. CONCLUSION: Factors placing individuals with knee OA at greater risk of a poor function outcome by at least 1 of the 2 function measures included the local factors laxity and proprioceptive inaccuracy, as well as age, BMI, and knee pain intensity. Factors protecting against a poor function outcome included strength, the psychosocial factors mental health, self-efficacy, and social support, and the activity level measured by the amount of aerobic exercise per week. The identification of these factors provides possible targets for rehabilitative and self-management strategies to prevent disability.