Feasibility study of an insole-type active assist device for ankle alignment correction during stepping in patients with knee osteoarthritis.

Introduction: Lateral wedge insole (LWI) is one of the therapeutic interventions in the management of medial compartment knee osteoarthritis. The aim of this study was to investigate the effect of the LWI with and without a medial arch on the pain and the ankle function in patients with medial compartment knee osteoarthritis. Methods and Materials: Twenty-six people with medial knee osteoarthritis were assigned. All participants were asked to complete the questionnaires of the Foot and Ankle Outcome Survey (FAOS) and the Visual Analog Scale (VAS) in the first session. Then, participants were divided into two groups. The first group was given a LWI and the second group a LWI with the medial arch support. After a 6-weeks use of the insoles, participants were asked to complete the questionnaires again. Result: The use of LWI and arch support did not alter all items of the FAOS including the stiffness, pain, activity level, sports restriction, and quality of life restrictions and the VAS score after six weeks compared with the first session (P>0.05), but the using only LWI increased all subscales of FAOS and VAS score after six weeks wearing the insole (P<0.05) and there was no significant change just in the stiffness subscale (P=0.6). Also, the difference between the two groups was significant by increase of all outcomes using only the LWI compared with the LWI along with an arch support (P<0.05). Conclusion: Using a LWI in isolation can result in pain and discomforting in the ankle joint. However, LWI combined with arch support could prevent joint stiffness, pain and discomforting in the ankle joint of patients with medial knee osteoarthritis. Keywords: Ankle; Arch support; Function; Lateral wedge Insole; Medial Knee Osteoarthritis; Pain

The aim of this study was to evaluate the thickness of the medial collateral ligament (MCL) sonographically in individuals with medial compartment knee osteoarthritis and to investigate its relationship with femoral cartilage thickness, pain, and functional status. This cross-sectional study included 21 patients diagnosed with medial compartment knee osteoarthritis radiologically (Kellgren-Lawrence grade 2 or 3) and 21 age- and sex-matched healthy individuals. MCL thickness was measured using ultrasonography approximately 1cm proximal and 1cm distal to the medial joint line. Femoral cartilage thickness was assessed at the medial condyle, intercondylar area, and lateral condyle. Pain levels were evaluated using the Visual Analog Scale (VAS), and functional status was assessed using the KOOS-PS (Knee Injury and Osteoarthritis Outcome Score-Physical Function Shortform). Proximal MCL thickness was significantly greater in the osteoarthritis group compared to the control group (2.0 ± 0.3mm vs. 1.6 ± 0.2mm, p < 0.001); distal MCL thickness was also significantly increased (1.5 ± 0.2mm vs. 1.2 ± 0.1mm, p = 0.002). Femoral cartilage thickness was significantly lower in patients with osteoarthritis than in healthy controls at the medial condyle (0.21 ± 0.03cm vs. 0.26 ± 0.02cm, p < 0.001), intercondylar area (0.25 ± 0.03cm vs. 0.29 ± 0.02cm, p < 0.001), and lateral condyle (0.21 ± 0.04cm vs. 0.25 ± 0.03cm, p = 0.005). A weak negative correlation was found between proximal MCL thickness and both medial (rho = -0.360, p = 0.022) and intercondylar (rho = -0.373, p = 0.018) cartilage thickness. A moderate negative correlation was observed between both proximal (rho = -0.523, p = 0.001) and distal (rho = -0.587, p < 0.001) MCL thicknesses and KOOS-PS scores. MCL thickness increases in medial knee osteoarthritis, and this thickening is negatively associated with both cartilage thickness and functional status. These findings suggest that the degeneration process in medial knee osteoarthritis is not limited to cartilage alone; surrounding soft tissue structures such as the MCL may also be affected. Careful sonographic examination of the MCL will contribute to a more optimal evaluation of this patient group. Key Points • This is the first study to evaluate medial collateral ligament (MCL) thickness sonographically in patients with medial knee osteoarthritis. • MCL thickness was significantly increased in osteoarthritis patients and negatively correlated with both femoral cartilage thickness and functional status. • Findings suggest that osteoarthritis affects not only cartilage but also periarticular soft tissues such as the MCL. • Sonographic assessment of the MCL may provide additional insights for diagnosis and management of medial knee osteoarthritis.

Control of frontal plane knee laxity during gait in patients with medial compartment knee osteoarthritis

Proximal femur shape differs between subjects with lateral and medial knee osteoarthritis and controls: the Osteoarthritis Initiative

Few if any prevention strategies are available for knee osteoarthritis (OA). In those with symptomatic medial OA, the contralateral knee may be at high risk of disease, and a reduction in medial loading in that knee might prevent disease or its progression there. Our aim was to determine how often persons with medial OA on 1 side had either concurrent or later medial OA on the contralateral side, and whether an intervention known to reduce medial loading in affected knees with medial OA might reduce medial loading in the contralateral knee. Lateral wedge insoles reduce loading across an affected medial knee but their effect on the contralateral knee is unknown. To determine the proportion of persons with medial knee OA who had concurrent medial contralateral OA or developed contralateral medial OA later, we examined knee radiographs from the longitudinal Framingham Osteoarthritis Study. Then, to examine an approach to reducing medial load in the contralateral knee, 51 people from a separate study with painful medial tibiofemoral OA underwent gait analysis wearing bilateral controlled shoes with no insoles, and then with 2 types of wedge insoles laterally posted by 5°. Primary outcome was the external knee adduction moment (EKAM) in the contralateral knee. Nonparametric CI were constructed around the median differences in percentage change in the affected and contralateral sides. Of Framingham subjects with medial radiograph knee OA, 137/152 (90%) either had concurrent contralateral medial OA or developed it within 10 years. Of those with medial symptomatic knee OA, 43/67 (64%) had or developed the same disease state in the contralateral knee. Compared to a control shoe, medial loading was reduced substantially on both the affected (median percentage EKAM change -4.84%; 95% CI -11.33% to -0.65%) and contralateral sides (median percentage EKAM change -9.34%; 95% CI -10.57% to -6.45%). In persons with medial OA, the contralateral knee is also at high risk of medial OA. Bilateral reduction in medial loading in knees by use of strategies such as lateral wedge insoles might not only reduce medial load in affected knees but prevent knee OA or its progression on the contralateral side.

<h3>Objective.</h3> Few if any prevention strategies are available for knee osteoarthritis (OA). In those with symptomatic medial OA, the contralateral knee may be at high risk of disease, and a reduction in medial loading in that knee might prevent disease or its progression there. Our aim was to determine how often persons with medial OA on 1 side had either concurrent or later medial OA on the contralateral side, and whether an intervention known to reduce medial loading in affected knees with medial OA might reduce medial loading in the contralateral knee. Lateral wedge insoles reduce loading across an affected medial knee but their effect on the contralateral knee is unknown. <h3>Methods.</h3> To determine the proportion of persons with medial knee OA who had concurrent medial contralateral OA or developed contralateral medial OA later, we examined knee radiographs from the longitudinal Framingham Osteoarthritis Study. Then, to examine an approach to reducing medial load in the contralateral knee, 51 people from a separate study with painful medial tibiofemoral OA underwent gait analysis wearing bilateral controlled shoes with no insoles, and then with 2 types of wedge insoles laterally posted by 5°. Primary outcome was the external knee adduction moment (EKAM) in the contralateral knee. Nonparametric CI were constructed around the median differences in percentage change in the affected and contralateral sides. <h3>Results.</h3> Of Framingham subjects with medial radiograph knee OA, 137/152 (90%) either had concurrent contralateral medial OA or developed it within 10 years. Of those with medial symptomatic knee OA, 43/67 (64%) had or developed the same disease state in the contralateral knee. Compared to a control shoe, medial loading was reduced substantially on both the affected (median percentage EKAM change −4.84%; 95% CI −11.33% to −0.65%) and contralateral sides (median percentage EKAM change −9.34%; 95% CI −10.57% to −6.45%). <h3>Conclusion.</h3> In persons with medial OA, the contralateral knee is also at high risk of medial OA. Bilateral reduction in medial loading in knees by use of strategies such as lateral wedge insoles might not only reduce medial load in affected knees but prevent knee OA or its progression on the contralateral side.

Results on the effects of lateral wedge insoles (LWIs) in patients with medial knee osteoarthritis (OA) are ambiguous and not fully understood. Because of the low cost of this intervention and its clinical utility, attention to LWIs is worth considering. Current insights on the efficacy of LWIs are mainly focused on changing biomechanical aspects, such as the external knee adduction moment, in an attempt to influence pain, functional ability and structural progression. It is however appropriate to interpret the effectiveness of LWIs in a broader concept than the pure biomechanical approach. Given our current understanding of OA-related pain, including the involvement of the central nervous system and nociception-motor interactions, concepts of pain neuroscience should be taken into account. The purpose of this review is to summarize the current state of knowledge regarding the biomechanical effect of LWIs. It aims to discuss the degree to which such biomechanical effect translates to clinical effects (symptom relief, function recovery and reduction of structural progression). In order to explain these clinical effects, this paper balances biomechanics with pain neuroscience. A literature search was performed and reviewed using a narrative approach. Many studies investigated the effect of LWIs on dynamic knee joint loading, and beneficial biomechanical effects (reduction in knee adduction moment) were observed in patients with mild to moderate medial knee OA, in particular when using full-length LWIs. However, despite beneficial biomechanical effects, there is insufficient evidence for clinically important effects or significant reductions in disease progression. Evaluating the effects of LWIs, our current understanding of OA pain should be taken into account, as LWIs may be part of a comprehensive biopsychosocial treatment. Future work on all of the variables that could influence clinical outcomes in order to decide in which subgroups of patients LWIs are (most) effective is necessary.

Background Lateral thrust seen in people with medial compartment knee osteoarthritis can cause dynamic knee instability and poor postural control during gait cycles. A lateral wedge insole can reduce the lateral thrust and may have a favorable effect on gait variability, which in turn may indicate gait instability improves. The aim of this study was to investigate the effect of lateral wedge insole on gait variability in knee osteoarthritis patients. Method We involved 15 symptomatic knee osteoarthritis patients who were provided with lateral wedge insole and 13 healthy asymptomatic volunteers as the control group. The gait variability was evaluated as the coefficient of variation of stride, stance, and swing duration based on acceleration monitoring using a wearable sensor. The lateral thrust was estimated as the lateral acceleration peak on the shank sensor. These measurements were performed without lateral wedge insole (baseline), immediately with lateral wedge insole (T0) at the initial office visit and one month after intervention (T1). Result Our data showed that the stance duration coefficient of variation and lateral thrust at T1 in the knee osteoarthritis group, were significantly decreased compared to the baseline values and these values were identical to those in the control group. Conclusion The lateral wedge insole reduces dynamic knee instability and could improve gait variability in medial compartment knee osteoarthritis.

BackgroundPronated foot posture is associated with many clinical and biomechanical outcomes unique to medial compartment knee osteoarthritis (OA). Though shoe-worn insole treatment, including lateral wedges, is commonly studied in this patient population, their effects on the specific subgroup of people with medial knee OA and concomitant pronated feet are unknown. The purpose of this study was to evaluate whether lateral wedge insoles with custom arch support are more beneficial than lateral wedge insoles alone for knee and foot symptoms in people with medial tibiofemoral knee osteoarthritis (OA) and pronated feet.MethodsTwenty-six people with pronated feet and symptomatic medial knee OA participated in a randomized crossover study comparing five degree lateral wedge foot insoles with and without custom foot arch support. Each intervention was worn for two months, separated by a two-month washout period of no insoles wear. Main outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function subscales, the revised short-form Foot Function Index (FFI-R) pain and stiffness subscales, and the timed stair climb test. Regression modeling was conducted to examine treatment, period, and interaction effects.ResultsTwenty-two participants completed the study, and no carryover or interaction effects were observed for any outcome. Significant treatment effects were observed for the timed stair climb, with greater improvements seen with the lateral wedges with arch support. Within-condition significant improvements were observed for WOMAC pain and physical function, as well as FFI-R pain and stiffness with lateral wedges with arch support use. More adverse effects were reported with the lateral wedges alone, while more people preferred the lateral wedges with arch support overall.ConclusionsAddition of custom arch support to a standard lateral wedge insole may improve foot and knee symptoms in people with knee OA and concomitant pronated feet. These preliminary findings suggest further research evaluating the role of shoe-worn insoles for treatment of this specific sub-group of people with knee OA is warranted.Trial registrationClinicaltrials.gov identifier: NCT02234895.

Effects of a 10-week toe-out gait modification intervention in people with medial knee osteoarthritis: a pilot, feasibility study

Individuals with medial knee osteoarthritis (OA) experience knee laxity and instability. Strategies aimed at muscle stabilization may influence the long-term integrity of the joint. This study sought to determine how individuals with medial knee OA respond to a rapid valgus knee movement, to investigate the relationship between muscle-stabilization strategies and knee instability. Twenty-one subjects with medial knee OA and genu varum and 19 control subjects were tested. Subjects stood with the test limb on a movable platform, comprising a plate that translated laterally to rapidly stress the knee's medial periarticular structures and create a potentially destabilizing sensation at the knee joint. Knee motion and muscle responses were recorded. Subjects rated the condition of their knee with a self-report questionnaire about knee instability during daily activities. Prior to plate movement, the OA subjects demonstrated more medial muscle co-contraction than did controls (P = 0.014). Following plate movement, the OA subjects shifted less weight off the test limb (P = 0.013) and had greater medial co-contraction (P = 0.037). OA subjects without knee instability had higher co-contraction of the vastus medialis medial hamstrings than did those who reported having instability that affected their daily activities (P = 0.038). More knee stability correlated positively with higher co-contraction of the vastus medialis medial hamstrings prior to plate movement (r = 0.459, P = 0.042). Individuals with medial knee OA attempt to stabilize the knee with greater co-contraction of the medial muscle in response to laxity that appears on the medial side of the joint only. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction, and therefore needs to be altered to slow or stop the progression of the OA disease process.

Medial compartment knee osteoarthritis (OA) is the most common form of knee OA and can be influenced by off-axis (frontal and transverse plane) biomechanics. Abnormalities such as varus malalignment, elevated knee adduction moment (KAM), dynamic varus thrust, altered step width, lateral trunk lean, reduced tibial rotation, and abnormal foot progression angle (FPA) contribute to excessive medial loading and are associated with symptom severity and structural progression. These modifiable factors present important targets for conservative management. This mini-review synthesizes current evidence on off-axis biomechanical impairments in medial knee OA and evaluates rehabilitation strategies designed to modify these mechanics. Gait retraining strategies, particularly personalized FPA modification, can reduce KAM and improve pain, with real-time biofeedback enhancing effectiveness. Valgus off-loader bracing alleviates pain related to medial knee OA and may be used as an adjunct for appropriately selected patients, especially when combined with practitioner guidance on brace fit and use. Lateral wedge insoles may provide small biomechanical benefits in a subset of individuals, while its effectiveness on symptom relief is not affirmative. Hip abductor strengthening reliably improves symptoms and function, although its load-modifying mechanisms and structural benefits remain unclear. Overall, current evidence supports a personalized, biomechanically informed approach targeting on off-axis biomechanics to managing medial knee OA. Future work should prioritize long-term randomized controlled trials and precision-based methods to identify individuals most likely to benefit from off-axis biomechanical interventions. Future clinical trials should also distinguish structural and functional off-axis biomechanical factors to optimize intervention effectiveness across distinct biomechanical phenotypes within medial knee OA.

PMS73 EFFECTIVENESS OF USING THE UNLOADER - ONE KNEE BRACE ON THE PHYSICAL ACTIVITY AMONG PERSONS WITH MEDIAL KNEE OSTEOARTHRITIS (OA)

Association of walking cadence with knee adduction angular impulse while controlling for speed in patients with knee osteoarthritis

Individuals with medial compartment knee osteoarthritis (OA) and genu varum use different movement and muscle activation patterns to increase joint stability during gait. The purpose of this study was to ascertain whether opening-wedge high-tibial osteotomy (OW-HTO) corrected pathomechanical abnormalities associated with the progression of knee OA. Fifteen patients diagnosed with medial knee OA and genu varum who were scheduled for OW-HTO were tested prior to and 1 year following OW-HTO. Fifteen age- and sex-matched controls were also tested. Frontal plane laxity was measured from stress radiographs. All participants underwent quadriceps strength testing with a burst superimposition technique and gait analysis with surface electromyography to calculate knee joint kinematics and kinetics and muscle co-contraction during the stance phase of gait. Participants rated their knee function and instability using a self-report questionnaire. Static alignment improved following the surgery. Medial laxity (P = 0.003) and instability (P = 0.002) significantly improved, and statistical reductions in the adduction moment resulted in lower levels of vastus medialis-medial gastrocnemius muscle co-contractions (P = 0.089). Despite improvements in global rating of knee function (P = 0.001), the OA group's ratings remained significantly lower than those of the healthy controls (P = 0.001). Quadriceps strength deficits and knee flexion impairments persisted. Persistent quadriceps weakness and impaired knee kinematics after realignment suggest that the movement strategy may perpetuate joint destruction and impede the long-term success of realignment. Rehabilitation should focus on quadriceps strength and improving joint mobility to improve the long-term function of individuals with medial knee OA.