Ground reaction force patterns in knees with and without radiographic osteoarthritis and pain: descriptive analyses of a large cohort (the Multicenter Osteoarthritis Study).

OBJECTIVE: To compare ground reaction force patterns (GRF) during walking among legs defined by presence or absence of knee pain and/or radiographic knee osteoarthritis (ROA). METHOD: Principal component analysis extracted major modes of variation (PCs) in GRF data from the Multicenter Osteoarthritis Study during self-paced walking. Legs were categorized as pain + ROA (n = 168), ROA only (n = 303), pain only (n = 476), or control (n = 1877). Relationships between group and GRF PCs were examined using Generalized Estimating Equations, adjusted for age, sex, body mass index, race, and clinic site with and without additional adjustment for gait speed. RESULTS: With or without speed adjustment, pain + ROA had flatter vertical GRF waveforms than control (speed adjusted PC2 difference [95%CI]: -66 [-113,-20]), pain + ROA and ROA only had higher lateral GRF at impact and greater mid-stance medial GRF than control (speed adjusted PC3 difference: 9 [3,16] and 6 [2,10], respectively), and ROA only had higher early vs late medial GRF than control (speed adjusted PC2 difference: 7 [2,13]). Pain only had flatter vertical GRF waveforms and a smaller difference between anterior and posterior GRF than control only without speed adjustment. CONCLUSION: In this large sample, sustained mid-stance loading and higher impact loads were identified in legs with ROA or ROA and pain, even when adjusting for differences in gait speed and other confounders. While it remains to be seen whether these features precede or result from ROA and pain, the presence of these patterns in the speed-adjusted models could have implications on gait interventions aimed to change joint loading.

Can Yoga or Physical Therapy for Chronic Low Back Pain Improve Depression and Anxiety Among Adults From a Racially Diverse, Low-Income Community? A Secondary Analysis of a Randomized Controlled Trial.

OBJECTIVE: To determine and compare the effect of yoga, physical therapy (PT), and education on depressive and anxious symptoms in patients with chronic low back pain (CLBP). DESIGN: Secondary analysis of a randomized controlled trial. SETTING: Academic safety net hospital and 7 community health centers. PARTICIPANTS: A total of 320 adults with CLBP. INTERVENTION: Yoga classes, PT sessions, or an educational book. OUTCOME MEASURE: Depression and anxiety were measured using the Patient Health Questionnaire and Generalized Anxiety Disorder 7-item Scale, respectively, at baseline, 12, and 52 weeks. We identified baseline and midtreatment (6-wk) factors associated with clinically meaningful improvements in depressive (≥3 points) or anxious (≥2 points) symptoms at 12 weeks. RESULTS: Participants (female=64%; mean age, 46.0±10.7 years) were predominantly non-White (82%), low-income (<$30,000/year, 59%), and had not received a college degree (71%). Most participants had mild or worse depressive (60%) and anxious (50%) symptoms. At 12 weeks, yoga and PT participants experienced modest within-group improvements in depressive symptoms (mean difference [MD]=-1.23 [95% CI, -2.18 to -0.28]; MD=-1.01 [95% CI, -2.05 to -0.03], respectively). Compared with the education group, 12-week differences were not statistically significant, although trends favored yoga (MD=-0.71 [95% CI, -2.22 to 0.81]) and PT (MD= -0.32 [95% CI, -1.82 to 1.18]). At 12 weeks, improvements in anxious symptoms were only found in participants who had mild or moderate anxiety at baseline. Independent of treatment arm, participants who had 30% or greater improvement in pain or function midtreatment were more likely to have a clinically meaningful improvement in depressive symptoms (odds ratio [OR], 1.82 [95% CI, 1.03-3.22]; OR, 1.79 [95% CI, 1.06-3.04], respectively). CONCLUSIONS: In our secondary analysis we found that depression and anxiety, common in this sample of underserved adults with CLBP, may improve modestly with PT and yoga. However, effects were not superior to education. Improvements in pain and function are associated with a decrease in depressive symptoms. More research is needed to optimize the integration of physical and psychological well-being in PT and yoga.

Exerted running results in altered impact mechanics and footstrike patterns following gait retraining.

Exertion may alter running mechanics and increase injury risk. Effects of exertion following gait-retraining are unknown. OBJECTIVES: To determine how exertion effects load rates, footstrike, and cadence in runners following a transition to forefoot strike (FFS) or increased cadence (CAD) gait-retraining. METHODS: 33 (9 M, 24 F) healthy rearfoot strike runners were randomized into CAD or FFS groups. All runners received strengthening exercises and gait-retraining. 3D kinetic and kinematic motion analysis with instrumented treadmill at self-selected speed was performed at baseline & 1-week post-intervention, including an exerted run. Exertion was ≥17 on Borg's Rating of Perceived Exertion scale or voluntary termination of running. RESULTS: Within group comparisons between fresh and exerted running: Cadence not affected in either group. Foot angle at contact became less plantarflexed in FFS (-2.2°, ±0.4) and was unchanged in CAD. Both groups increased vertical average load rate (FFS +16.9%, CAD +13.6%). CAD increased vertical stiffness (+8.6 kN/m). FFS reduced ankle excursion (1.8°). (p ≤ 0.05 for all values listed). CONCLUSION: Both FFS and CAD exhibited increased load rates with exertion. Variables that may have increased load rates were different for each group. CAD runners had increased vertical stiffness while FFS runners had reduced plantarflexion at contact and reduced ankle dorsiflexion excursion.

[Anesthesia in patients with dopa-responsive dystonia (Segawa syndrome) : Presentation of the pathophysiology, clinical picture and approach based on two case reports]. / Anästhesieführung bei Patienten mit Dopa-responsiver Dystonie (Segawa-Syndrom) : Darstellung der Pathophysiologie, Klinik und Vorgehensweise anhand zweier Fallberichte.

Segawa syndrome (dopa-responsive dystonia [DRD]) is a rare neurometabolic disorder characterized by progressive dystonia, diurnal variation and tremors. It is caused by an enzymatic defect (a mutation of the GTPCH1 gene located on chromosome 14q) in the synthesis of tetrahydrobiopterin, an important substrate for dopamine synthesis. In the case of early correct diagnosis, clinical symptoms are well-controlled by levodopa therapy. The disease has several features which may lead to organ dysfunctions (e.g. torticollis, scoliosis, dysphagia and immobilization), which may be of concern for the anesthesiologist. Presenting two case reports of female patients undergoing elective cesarean section and breast cancer surgery, the main principles of perioperative management are discussed. Either techniques of regional or general anesthesia can be performed safely. Preoperative medication with levodopa should not be interrupted. Pharmacological agents with an antidopaminergic mode of action have to be avoided as well as significant pain and emotional stress situations in the perioperative period. Surgery in an ambulatory setting may not be recommended.

Analysis of the calcium paradox of renin secretion.

The secretion of the protease renin from renal juxtaglomerular cells is enhanced by subnormal extracellular calcium concentrations. The mechanisms underlying this atypical effect of calcium have not yet been unraveled. We therefore aimed to characterize the effect of extracellular calcium concentration on calcium handling of juxtaglomerular cells and on renin secretion in more detail. For this purpose, we used a combination of experiments with isolated perfused mouse kidneys and direct calcium measurements in renin-secreting cells in situ. We found that lowering of the extracellular calcium concentration led to a sustained elevation of renin secretion. Electron-microscopical analysis of renin-secreting cells exposed to subnormal extracellular calcium concentrations revealed big omega-shaped structures resulting from the intracellular fusion and subsequent emptying of renin storage vesicles. The calcium concentration dependencies as well as the kinetics of changes were rather similar for renin secretion and for renovascular resistance. Since vascular resistance is fundamentally influenced by myosin light chain kinase (MLCK), myosin light chain phosphatase (MLCP), and Rho-associated protein kinase (Rho-K) activities, we examined the effects of MLCK-, MLCP-, and Rho-K inhibitors on renin secretion. Only MLCK inhibition stimulated renin secretion. Conversely, inhibition of MCLP activity lowered perfusate flow and strongly inhibited renin secretion, which could not be reversed by lowering of the extracellular calcium concentration. Renin-secreting cells and smooth muscle cells of afferent arterioles showed immunoreactivity of MLCK. These findings suggest that the inhibitory effect of calcium on renin secretion could be explained by phosphorylation-dependent processes under control of the MLCK.

Varus thrust during walking and the risk of incident and worsening medial tibiofemoral MRI lesions: the Multicenter Osteoarthritis Study.

OBJECTIVE: To determine the association of varus thrust during walking to incident and worsening medial tibiofemoral cartilage damage and bone marrow lesions (BMLs) over 2 years in older adults with or at risk for osteoarthritis (OA). METHOD: Subjects from the Multicenter Osteoarthritis Study (MOST) were studied. Varus thrust was visually assessed from high-speed videos of forward walking trials. Baseline and two-year MRIs were acquired from one knee per subject and read for cartilage loss and BMLs. Logistic regression with generalized estimating equations was used to estimate the odds of incident and worsening cartilage loss and BMLs, adjusting for age, sex, race, body mass index (BMI), and clinic site. The analysis was repeated stratified by varus, neutral, and valgus alignment. RESULTS: 1007 participants contributed one knee each. Varus thrust was observed in 29.9% of knees. Knees with thrust had 2.17 [95% CI: 1.51, 3.11] times the odds of incident medial BML, 2.51 [1.85, 3.40] times the odds of worsening medial BML, and 1.85 [1.35, 2.55] times the odds of worsening medial cartilage loss. When stratified by alignment, varus knees also had significantly increased odds of these outcomes. CONCLUSION: Varus thrust observed during walking is associated with increased odds of incident and worsening medial BMLs and worsening medial cartilage loss. Increased odds of these outcomes persist in varus-aligned knees.

Prospective change in daily walking over 2 years in older adults with or at risk of knee osteoarthritis: the MOST study.

OBJECTIVE: Radiographic disease and knee pain are thought to decrease physical activity in people with knee osteoarthritis (OA), but this has not been formally studied. We examined change in objectively measured daily walking over 2 years and evaluated the association of certain risk factors with reduced walking among adults with or at risk of knee OA. DESIGN: Steps/day over 7 days were collected at baseline and 2 years later in subjects with or at risk of knee OA from the Multicenter Osteoarthritis Study using a StepWatch. We evaluated the presence of radiographic knee osteoarthritis (ROA), knee pain, worsening of ROA and pain over 2 years, obesity, depressive symptoms, living situation, catastrophizing, fatigue, widespread pain and comorbidities with 2-year change in daily walking using regression models adjusted for potential confounders. RESULTS: 1318 met inclusion criteria (age 66.9 ± 7.7, 59% women, BMI 30.6 ± 5.9) and walked 126 ± 1700 steps/day fewer steps at 2 years (95% CI [-218, -35]). People with depressive symptoms at baseline walked 455 fewer steps/day [-872, -68], and there was a trend for people with ROA worsening to walk 183 fewer steps/day [-377.5, 11.7]. No other factors met statistical significance for change in daily walking. CONCLUSION: Adults with or at risk of knee OA experienced only minimal declines in daily walking over 2 years. Nonetheless, depressive symptoms and may be worsening ROA are associated with a decline in steps/day in adults with or at risk of knee OA.

Electrical conductivity of oxidized-graphenic nanoplatelets obtained from bamboo: effect of the oxygen content.

The large-scale production of graphene and reduced-graphene oxide (rGO) requires low-cost and eco-friendly synthesis methods. We employed a new, simple, cost-effective pyrolytic method to synthetize oxidized-graphenic nanoplatelets (OGNP) using bamboo pyroligneous acid (BPA) as a source. Thorough analyses via high-resolution transmission electron microscopy and electron energy-loss spectroscopy provides a complete structural and chemical description at the local scale of these samples. In particular, we found that at the highest carbonization temperature the OGNP-BPA are mainly in a sp(2) bonding configuration (sp(2) fraction of 87%). To determine the electrical properties of single nanoplatelets, these were contacted by Pt nanowires deposited through focused-ion-beam-induced deposition techniques. Increased conductivity by two orders of magnitude is observed as oxygen content decreases from 17% to 5%, reaching a value of 2.3 × 10(3) S m(-1) at the lowest oxygen content. Temperature-dependent conductivity reveals a semiconductor transport behavior, described by the Mott three-dimensional variable range hopping mechanism. From the localization length, we estimate a band-gap value of 0.22(2) eV for an oxygen content of 5%. This investigation demonstrates the great potential of the OGNP-BPA for technological applications, given that their structural and electrical behavior is similar to the highly reduced rGO sheets obtained by more sophisticated conventional synthesis methods.

The relation of MRI-detected structural damage in the medial and lateral patellofemoral joint to knee pain: the Multicenter and Framingham Osteoarthritis Studies.

OBJECTIVE: To examine the relation of cartilage loss and bone marrow lesions (BMLs) in the medial and lateral patellofemoral joint (PFJ) to knee pain. METHODS: We categorized the location of full-thickness cartilage loss and BMLs in the PFJ on knee magnetic resonance imaging (MRIs) from the Multicenter Osteoarthritis (MOST) and Framingham Osteoarthritis (FOA) Studies as no damage, isolated medial, isolated lateral, or both medial and lateral (mixed). We determined the relation of MRI lesions in each PFJ region to prevalent knee pain. Differences in knee pain severity were compared among categories of PFJ full-thickness cartilage loss and BMLs using quantile regression. RESULTS: In MOST (n = 1137 knees), compared with knees without full-thickness cartilage loss, knees with isolated lateral or mixed PFJ full-thickness cartilage loss had 1.9 (1.3, 2.8) and 1.9 (1.2, 2.9) times the odds of knee pain, respectively, while isolated medial cartilage loss had no association with knee pain. BMLs in both the medial and lateral PFJ had 1.5 (1.1, 2.0) times the odds of knee pain compared with knees without BMLs. Knee pain severity was lowest in knees with isolated medial PFJ cartilage loss or BMLs. In FOA (n = 934 knees), neither isolated medial nor lateral cartilage loss was associated with knee pain, whereas isolated BMLs in either region were associated with pain. CONCLUSIONS: Results were not completely concordant but suggest that knee pain risk and severity is greatest with cartilage loss isolated to (MOST) or inclusive of (MOST and FOA) the lateral PFJ. While BMLs in either the medial or lateral PFJ are related to pain.

Floral isolation is the major reproductive barrier between a pair of rewarding orchid sister species.

The crucial role of reproductive isolation in speciation has long been recognized; however, a limited number of studies quantify different isolation barriers and embed reproductive isolation in a phylogenetic context. In this study, we investigate reproductive isolation between the often sympatrically occurring orchid species, Gymnadenia conopsea and G. odoratissima. We examine the phylogenetic relationship between the two species and analyse floral isolation, fruit set and seed viability from interspecies crosses, as well as the ploidy level. Additionally, we quantify interspecies differences in floral signals and morphology. The results suggest that the two species have a sister-species relationship. In terms of reproductive isolation, we found complete floral isolation between the two species, but little to no post-pollination isolation; the species also mostly had the same ploidy level in the studied populations. We also show clear distinctions in floral signals, as well as in floral size and spur length. We propose that respective adaptation to short- vs. long-tongued pollinators was the driver of speciation in the here studied Gymnadenia species. Our study supports the key role of floral isolation in orchid speciation and shows that floral isolation is not restricted to highly specialized pollination systems, but can also occur between species with less specialized pollination.

Effects of AFO use on walking in boys with Duchenne muscular dystrophy: a pilot study.

PURPOSE: Although bracing in the late ambulatory stage of Duchenne muscular dystrophy (DMD) has been described, the effects of ankle-foot orthoses (AFOs) in earlier stages have not been evaluated. The aim of this pilot study was to describe the effects of dynamic response AFO (DR-AFO) use in boys with DMD who are ambulatory. METHODS: Using a crossover design, 3 boys were randomly assigned to either a 2-week DR-AFO or a placebo intervention. Phases were separated by a 1-week washout period. Primary outcomes were time to walk 10 m and a 6-Minute Walk Test. RESULTS: With DR-AFO use, declines in 10-m walk time (median decline = 0.8 s) and 6-Minute Walk Distance (median = 25.0 m) occurred. Parental report suggested that the use of DR-AFOs increased falls in 2 of 3 participants. CONCLUSION: This pilot study does not support the use of DR-AFOs by boys with DMD who are ambulatory.

Association of hip and pelvic geometry with tibiofemoral osteoarthritis: multicenter osteoarthritis study (MOST).

OBJECTIVE: Lateral tibiofemoral osteoarthritis (OA) is overall less common than medial tibiofemoral OA, but it is more prevalent in women. This may be explained by sex differences in hip and pelvic geometry. The aim of this study is to explore sex differences in hip and pelvic geometry and determine if such parameters are associated with the presence of compartment-specific knee OA. METHODS: This case-control study reports on 1,328 hips/knees from 664 participants and is an ancillary to the Multicenter Osteoarthritis Study (MOST). Of the 1,328 knees, 219 had lateral OA, 260 medial OA, and 849 no OA. Hip and pelvic measurements were taken from full-limb radiographs on the ipsilateral side of the knee of interest. After adjusting for covariates, means were compared between sexes and also between knees with medial and lateral OA vs no OA using separate regression models. RESULTS: Women were shown to have a reduced femoral offset (FO) (mean 40.9 mm vs 45.9 mm; P = 0.001) and more valgus neck-shaft angle (mean 128.4° vs 125.9°; P < 0.001) compared to men. Compared to those with no OA, knees with lateral OA were associated with a reduced FO (P = 0.012), increased height of hip centre (HHC) (P = 0.003), more valgus neck-shaft angle (P = 0.042), and increased abductor angle (P = 0.031). Knees with medial OA were associated with a more varus neck-shaft angle (P = 0.043) and a decreased abductor angle (P = 0.003). CONCLUSION: These data suggest anatomical variations at the hip and pelvis are associated with compartment-specific knee OA and may help to explain sex differences in patterns of knee OA.

Do radiographic disease and pain account for why people with or at high risk of knee osteoarthritis do not meet physical activity guidelines?

OBJECTIVE: Knee osteoarthritis (OA) and pain are assumed to be barriers to meeting physical activity guidelines, but this has not been formally evaluated. The purpose of this study was to determine the proportions of people with and those without knee OA and knee pain who meet recommended physical activity levels through walking. METHODS: We performed a cross-sectional analysis of community-dwelling adults from the Multicenter Osteoarthritis Study who had or who were at high risk of knee OA. Participants wore a StepWatch activity monitor to record steps per day for 7 days. The proportion of participants who met the recommended physical activity levels was defined as those accumulating≥150 minutes per week at ≥100 steps per minute in bouts lasting ≥10 minutes. These proportions were also determined for those with and those without knee OA, as classified by radiography and by severity of knee pain. RESULTS: Of the 1,788 study participants (mean±SD age 67.2±7.7 years, mean±SD body mass index 30.7±6.0 kg/m2, 60% women), lower overall percentages of participants with radiographic knee OA and knee pain met recommended physical activity levels. However, these differences were not statistically significant between those with and those without knee OA; 7.3% and 10.1% of men (P=0.34) and 6.3% and 7.8% of women (P=0.51), respectively, met recommended physical activity levels. Similarly, for those with moderate/severe knee pain and those with no knee pain, 12.9% and 10.9% of men (P=0.74) and 6.7% and 11.0% of women (P=0.40), respectively, met recommended physical activity levels. CONCLUSION: Disease and pain have little impact on achieving recommended physical activity levels among people with or at high risk of knee OA.

Valgus malalignment is a risk factor for lateral knee osteoarthritis incidence and progression: findings from the Multicenter Osteoarthritis Study and the Osteoarthritis Initiative.

OBJECTIVE: To study the effect of valgus malalignment on knee osteoarthritis (OA) incidence and progression. METHODS: We measured the mechanical axis from long limb radiographs from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) to define limbs with valgus malalignment (mechanical axis of ≥1.1° valgus) and examined the effect of valgus alignment versus neutral alignment (neither varus nor valgus) on OA structural outcomes. Posteroanterior radiographs and knee magnetic resonance (MR) images were obtained at the time of the long limb radiograph and at followup examinations. Lateral progression was defined as an increase in joint space narrowing (on a semiquantitative scale) in knees with OA, and incidence was defined as new lateral narrowing in knees without radiographic OA. We defined lateral cartilage damage and progressive meniscal damage as increases in cartilage or meniscus scores at followup on the Whole-Organ Magnetic Resonance Imaging Score scale (for the MOST) or the Boston Leeds Osteoarthritis Knee Score scale (for the OAI). We used logistic regression with adjustment for age, sex, body mass index, and Kellgren/Lawrence grade, as well as generalized estimating equations, to evaluate the effect of valgus alignment versus neutral alignment on disease outcomes. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS: We studied 5,053 knees (881 valgus) of subjects in the MOST cohort and 5,953 knees (1,358 valgus) of subjects in the OAI cohort. In both studies, all strata of valgus malalignment, including 1.1° to 3° valgus, were associated with an increased risk of lateral disease progression. In knees without radiographic OA, valgus alignment >3° was associated with incidence (e.g., in the MOST, adjusted OR 2.5 [95% CI 1.0-5.9]). Valgus alignment >3° was also associated with cartilage damage on MR imaging in knees without OA (e.g., in the OAI, adjusted OR 5.9 [95% CI 1.1-30.3]).We found a strong relationship of valgus malalignment with progressive lateral meniscal damage. CONCLUSION: Valgus malalignment increases the risk of knee OA radiographic progression and incidence as well as the risk of lateral cartilage damage. It may cause these effects, in part, by increasing the risk of meniscal damage.

Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage.

OBJECTIVE: To describe the prevalence of magnetic resonance imaging (MRI) detected structural damage in the patellofemoral joint (PFJ) and tibiofemoral joint (TFJ) in a population-based cohort. A secondary aim was to evaluate the patterns of compartmental involvement in knees with pain, between men and women, and in different age and body mass index (BMI) categories. METHODS: We studied 970 knees, one knee per subject, from the Framingham Osteoarthritis Study, a population-based cohort study of persons 51-92 years old. Cartilage damage and bone marrow lesions (BMLs) were assessed using the Whole Organ Magnetic Resonance Imaging Score (WORMS). The prevalence of isolated PFJ, isolated TFJ, and mixed structural damage was determined using the following definitions: any cartilage damage, full thickness cartilage loss, any BML, and the combination of full thickness cartilage loss with any BML. RESULTS: The mean age and BMI was 63.4 years and 28.6 m/kg(2), respectively; 57% were female. Isolated PFJ damage occurred in 15-20% of knees and isolated TFJ damage occurred in 8-17% of knees depending on the definition used. The prevalence of isolated PFJ damage was greater than isolated TFJ damage using all definitions except the any BML definition. This pattern was similar between genders and among age and BMI categories. In those with knee pain, isolated PFJ was at least as common as TFJ damage depending on the definition used. CONCLUSION: Using MRI to assess knee joint structural damage, isolated PFJ damage was at least as common as, if not more common than, isolated TFJ damage.

Walking to meet physical activity guidelines in knee osteoarthritis: is 10,000 steps enough?

OBJECTIVE: To study if step goals (eg, walking 10,000 steps a day) approximate meeting the 2008 Physical Activity Guidelines for Americans. DESIGN: Cross-sectional observational cohort. SETTING: Community. PARTICIPANTS: People with or at high risk of knee OA (N=1788). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Objective physical activity data were collected over 7 consecutive days from people with or at high risk of knee OA participating in the Multicenter Osteoarthritis Study. Using activity monitor data, we determined the proportion that (1) walked ≥10,000 steps per day, (2) met the 2008 Physical Activity Guidelines, and (3) achieved both recommendations. RESULTS: Of the subjects studied (mean age ± SD, 67±8y; mean body mass index ± SD, 31±6kg/m(2); 60% women), 16.7% of men and 12.6% of women walked ≥10,000 steps per day, while 6% of men and 5% of women met the 2008 Physical Activity Guidelines for Americans. Of those walking ≥10,000 steps per day, 16.7% and 26.7% of men and women, respectively, also met the 2008 Physical Activity Guidelines. CONCLUSIONS: Among this sample of older adults with or at high risk of knee OA, walking ≥10,000 steps a day did not translate into meeting public health guidelines. These findings highlight the disparity between the number of steps believed to be needed per day and the recommended time-intensity guidelines to achieve positive health benefits.

Relation of Temporal Asymmetry During Walking to Two-Year Knee Pain Outcomes in Those With Mild-to-Moderate Unilateral Knee Pain: An Exploratory Analysis From the Multicenter Osteoarthritis Study.

OBJECTIVE: We aimed to explore the cross-sectional relation of unilateral knee pain severity and temporal asymmetry during walking and to determine relations of temporal asymmetry during walking to 2-year changes in ipsilateral and contralateral knee pain in those with mild-to-moderate unilateral knee pain. METHODS: The Multicenter Osteoarthritis Study is a prospective cohort study of adults with or at risk for knee osteoarthritis. The current study included participants with unilateral knee pain. Gait was assessed during self-selected and fast walking at baseline. Knee pain was assessed at baseline and 2 years. We calculated limb symmetry indices (LSIs; nonpainful limb/painful limb × 100) for stance, single-limb support time, and double-limb support time, then examined their relations to unilateral knee pain severity, incident contralateral knee pain, and persistent ipsilateral knee pain. RESULTS: Unilateral knee pain severity was not associated with temporal asymmetry during self-selected or fast walking. At 2 years, 17.1% of participants had incident contralateral knee pain and 51.4% had persistent ipsilateral knee pain. For self-selected walking, greater LSIs (i.e., longer time on the nonpainful limb) for stance and single-limb support time were associated with decreased odds of incident contralateral knee pain. Measures of temporal asymmetry were not associated with persistent ipsilateral knee pain, except for single-limb support time during fast walking. CONCLUSION: For those with unilateral knee pain, temporal asymmetry during walking is not associated with pain severity. However, select measures of stance and single-limb support time during self-selected and fast walking relate to longitudinal knee pain outcomes.

Realignment treatment for medial tibiofemoral osteoarthritis: randomised trial.

OBJECTIVES: The objective of this 30-week randomised crossover trial was to determine whether a multi-modal realignment treatmentwould be successful in relieving pain and improving function among persons with medial tibiofemoral osteoarthritis (OA). METHODS: The authors conducted a double-blind randomised crossover trial of a multi-modal realignment treatment for medial tibiofemoral OA. Trial participants met American College of Rheumatology criteria for OA, with knee pain, aching or stiffness on most days of the past month and radiographic evidence of a definite osteophyte with predominant medial tibiofemoral OA. The authors tested two different treatments: (A) control treatment consisting of a neutral knee brace (no valgus angulation), flat unsupportive foot orthoses and shoes with a flexible mid-sole; and (B) active treatment consisting of a valgus knee brace, customised neutral foot orthoses and shoes designed for motion control. For each subject, the trial lasted 30 weeks, including 12 weeks each of active treatment and control treatment separated by a 6-week washout period. The primary outcome of the linear regression model was change in knee pain and function, as assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). RESULTS: 80 participants with medial tibiofemoral OA were randomised. Their mean age was 62 years, their mean body mass index was 34 kg/m(2) and their mean WOMAC Pain score was 9.2 (0-20 scale). There was no evidence of a carryover effect. The regression model demonstrated that the mean difference in pain between the active treatment and the control treatment was -1.82 units (95% CI -3.05 to -0.60; p=0.004) on the WOMAC Pain scale, indicating a small but statistically significant decrease in pain with the multi-modal active treatment. For WOMAC Function, the realignment intervention had a non-significant effect on function, with a -2.90 unit decrease (95% CI -6.60 to 0.79) compared with the control condition (p=0.12). CONCLUSION: Multi-modal realignment treatment decreases pain in persons with medial tibiofemoral OA.

Breaking the Law of Valgus: the surprising and unexplained prevalence of medial patellofemoral cartilage damage.

OBJECTIVES: To compare the prevalence of medial and lateral patellofemoral (PF) cartilage damage in three large osteoarthritis (OA) studies and determine the relationship of this damage to varus, neutral and valgus knee alignment. METHODS: In the Boston OA of the Knee, Framingham OA and Multicenter OA studies, MRIs were read for cartilage morphology at the medial and lateral patella and trochlea femoris using Whole-Organ MRI Scores (WORMS). WORMS scores ≥2 (any cartilage defect), ≥3 (areas of partial thickness loss), ≥4 (diffuse partial thickness loss) and ≥5 (extensive full thickness loss) were all variously considered as thresholds to identify damage that may indicate OA. Full-limb radiographs were measured for mechanical alignment, and varus (<-2°), neutral (-2° to 2°) and valgus (>2°) knees were identified. RESULTS: The prevalence of medial PF cartilage damage exceeded that of lateral damage in all three studies and according to nearly every threshold. Only among severely involved knees (WORMS ≥4 or ≥5) did the prevalence of lateral PF cartilage damage approximate that of medial damage. The high prevalence of medial PF damage persisted in all strata of knee alignment. Even among knees with valgus alignment, the prevalence of lateral PF cartilage damage equalled or surpassed that of medial PF damage only when the threshold was specific to severely involved knees. CONCLUSIONS: Medial PF cartilage damage is at least as prevalent within these older adult populations as lateral PF cartilage damage.