The effect of wedged insoles on the thrust of osteoarthritic knees

Use of accelerometry to detect varus thrust of osteoarthritic knees before and one year after high tibial osteotomy

BACKGROUND

The purpose of this study was to determine the effects of high tibial osteotomy (HTO) on varus thrust during gait in patients with medial compartment knee osteoarthritis (KOA), and to identify factors that influence thrust before and one year after surgery.

METHODS

HTO was performed in 60 KOA patients (70 knees, including 56 knees by open wedge and 14 by closed wedge). The control group comprised 28 normal, control subjects. Several parameters were evaluated before surgery and one year thereafter. Varus thrust was defined as acceleration of the thigh relative to the lower leg in the coronal plane. Knee-injury-and-osteoarthritis-outcome scores (KOOSs), knee joint angles, radiography, and mediolateral knee acceleration during free speed gait were measured and analyzed.

RESULTS

One-year after HTO, KOOSs, knee extension angles, and range of knee motion were improved (p < 0.001). The hip-knee-ankle angle and joint-line-convergent angle (JLCA) had decreased (p < 0.001), and walking speed had increased (p < 0.001). Preoperatively, patient acceleration was significantly (p < 0.05) higher than that of controls, and it did not change after HTO. However, it was reduced significantly (p < 0.05) after adjusting for walking speed. Walking speed correlated significantly with acceleration preoperatively, postoperatively, and among controls. Surgical methods (open-wedge/closed-wedge HTO) and correction angle did not affect postoperative acceleration. There was a low correlation between acceleration and KOOSs (KOOSa, KOOSp), knee joint angles, or JLCA postoperatively, but no relationship was found between acceleration and these parameters in the preoperative or the control group.

CONCLUSIONS

Walking speed correlated significantly with acceleration preoperatively, postoperatively, and with those of controls. Mediolateral acceleration of the thigh relative to the lower leg in patients with KOA was significantly higher than that of normal controls before surgery, and it did not change after HTO. However, after surgery it was reduced significantly after adjusting for walking speed.

Kinematic effects of lateral wedged insoles in patients with medial knee osteoarthritis

[Purpose] To examine the effect of lateral wedged insoles on the rotation mechanism of the knee joint in patients with knee osteoarthritis. [Participants and Methods] The participants included 11 patients with medial knee osteoarthritis. We asked all participants to stand up from a 40-cm-high chair, and we measured the rotation angle of the knee joint during the movement. The standing motion was performed under four conditions: barefoot and with 7-, 10-, and 13-mm lateral wedged insoles. We also measured four healthy participants as controls for comparison. [Results] During the standing motion, we internally rotated the tibia relative to the femur. In healthy participants, we measured 19.6° internal rotation of the tibia relative to the femur. Patients with knee osteoarthritis had internal rotations of approximately 9.8° when barefoot and 7.1°, 6.4°, and 7.1° when wearing lateral wedged insoles of 7, 10, and 13 mm, respectively. [Conclusion] Lateral wedged insoles do not modify the knee joint rotation motion of patients with knee OA to the correct style.

[Treatment of unicompartmental osteoarthritis of the knee]

Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.

The Effect of Lateral Wedge Insole on Gait Variability Assessed Using Wearable Sensors in Patients with Medial Compartment Knee Osteoarthritis

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.

Correlation of knee laxity with alignment and repetitive physical activity in patients with knee osteoarthritis: A cross-sectional study

BACKGROUND

Malalignment, knee laxity, and repetitive physical activity are considered biomechanical risk factors for knee osteoarthritis (KOA), though the correlation among these factors is poorly understood. The purpose of this study was to elucidate the relationship between knee laxity and alignment, and to determine the effects of repetitive physical activity on knee laxity in patients with KOA.

METHODS

The study subjects were 68 patients with radiographic tibiofemoral KOA and 68 control subjects. Each participant underwent clinical evaluation, muscle strength test, radiography, and knee laxity test. Laxity was evaluated before and after repetitive stepping exercise using tri-axial accelerometer.

RESULTS

Mediolateral acceleration correlated (P < 0.01) with two coronal alignments (mechanical axis: hip-knee-ankle angle (HKA); and joint line convergent angle (JLCA)). Pearson correlation coefficient was small (r = 0.23-0.24) before but increased after stepping (r = 0.28-0.33). Increased mediolateral acceleration after stepping correlated with JLCA (r = 0.37, P < 0.001). There were significant differences in coronal alignments, gait speed, mediolateral acceleration, and accelerations in all directions between the control and KOA groups. Anteroposterior acceleration did not correlate with sagittal knee alignment. Multiple logistic regression analysis identified HKA/JLCA, and increased mediolateral acceleration after stepping as significant diagnostic predictors of KOA.

CONCLUSIONS

We found a direct relationship between knee laxity and alignment or repetitive physical activity. Repetitive stepping activity significantly increased mediolateral acceleration in KOA patients, compared with the control. Stepping increased the correlation between mediolateral acceleration and coronal alignment. In knees with large JLCA, repetitive stepping caused much larger mediolateral laxity.

Relationship Between Knee Biomechanics and Pain in People With Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

Our primary aim was to determine the cross-sectional relationship between knee biomechanics during gait and pain in people with medial knee osteoarthritis. Our secondary aim was to evaluate differences in knee biomechanics between symptomatic and asymptomatic participants with medial knee osteoarthritis.

METHODS

Four online databases were searched from inception to July 2021. Eligible studies included people with medial/nonspecific knee osteoarthritis and a reported relationship between knee biomechanics during gait and pain or biomechanics of symptomatic and asymptomatic participants. Two reviewers independently extracted data and evaluated risk of bias. Random-effects meta-analyses were performed when three or more studies reported the same biomechanical variable for pooling (knee adduction moment [KAM], KAM impulse, varus thrust, and peak knee flexion moment [KFM]).

RESULTS

Forty studies were included. Methodological quality ranged from 4 to 9/10. Forty-seven unique biomechanical variables were reported. For the KAM, there was no correlation with pain for peak values pooled (early stance and overall) (r = 0.00, 95% confidence interval [95% CI]: -0.12, 0.11, k = 16), a small negative correlation for early stance peak alone (r = -0.09, 95% CI -0.18, -0.002, k = 12), and a medium positive correlation for the overall peak during stance (r = 0.30, 95% CI 0.17, 0.42, k = 4). Metaregression identified that body mass index moderated the peak KAM-pain relationship (P < 0.001). KAM impulse had a small positive correlation with pain (r = 0.23, 95% CI 0.04, 0.40, k = 5), and people with varus thrust had 3.84 greater odds of reporting pain compared with people without (95% CI 1.72, 8.53, k = 3). Meta-analyses for the peak KFM and pain correlation and secondary aim were nonsignificant.

CONCLUSION

Some knee gait biomechanics were associated with pain in this cohort. Longitudinal studies are required to determine causality.

Estimation of the External Knee Adduction Moment during Gait Using an Inertial Measurement Unit in Patients with Knee Osteoarthritis

Although the external knee adduction moment (KAM) during gait was shown to be a quantitative parameter of medial knee osteoarthritis (OA), it requires expensive equipment and a dedicated large space to measure. Therefore, it becomes a major reason to limit KAM measurement in a clinical environment. The purpose of this study was to estimate KAM using a single inertial measurement unit (IMU) during gait in patients with knee OA. A total of 22 medial knee OA patients (44 knee joints) performed conventional gait analysis using three-dimensional (3D) motion capture system. At the same time, we attached commercial IMUs to six body segments (sternum, pelvis, both thighs, and both shanks), and IMU signals during gait were recorded synchronized with the motion capture system. The peak-to-peak difference of acceleration in the lateral/medial axis immediately after heel contact was defined as the thrust acceleration (TA). We hypothesized that TA would represent the lateral thrust of the knee during the stance phase and correlate with the first peak of KAM. The relationship between the peak KAM and TA of pelvis (R = 0.52, p < 0.001), shanks (R = 0.57, p < 0.001) and thighs (R = 0.49, p = 0.001) showed a significant correlation. The root mean square error (RMSE) of linear regression models of pelvis, shanks, and thighs to estimate KAM were 0.082, 0.079, and 0.084 Nm/(kg·m), respectively. Our newly established parameter TA showed a moderate correlation with conventional KAM. The current study confirmed our hypothesis that a single IMU would predict conventional KAM during gait. Since KAM is known as an indicator for prognosis and severity of knee OA, this new parameter has the potential to become an accessible predictor for medial knee OA instead of KAM.

Validating Wearable Sensors Using Self-Reported Instability among Patients with Knee Osteoarthritis

BACKGROUND

Self-perceived instability among patients with knee osteoarthritis (OA) is defined as giving way, buckling, or shifting of the knee during activities, especially walking. Although instability is a leading cause of mobility decline with knee OA, methods for quantifying the symptom, determining the mechanisms, and establishing effective interventions remain unclear. Recently, data outputs (ie, linear acceleration and its time-derivative, jerk) from wearable sensors are showing strong associations with self-perceived instability among patients with other knee pathologies and may offer insight into OA-related instability.

OBJECTIVE

To examine discriminant and convergent validity of using data outputs from wearable sensors to quantify self-reported instability among patients with knee OA.

DESIGN

Secondary analysis of a cross-sectional study.

SETTING

Primary recruitment from an institutional outpatient physical therapy clinic and collection completed in an institutional research laboratory.

PATIENTS

Thirty-nine total participants. The OA group included 26 participants with radiographic evidence of moderate to severe knee OA in the medial compartment; knee pain >3 out of 10, and a walking speed of ≥1.0 m/s. The control group included 13 participants with no history of knee OA. Participants with current or history of low back, hip, or foot/ankle injury; knee replacement; skeletal realignment surgery; or comorbidities that limit walking, pregnancy, and inability to walk without an assistive device were excluded.

INTERVENTIONS

N/A MAIN OUTCOME MEASURES: Data output from wearable sensors at the tibia.

RESULTS

Midstance acceleration (P = .01) and jerk (P = .04) were significantly greater for those with than without knee OA. Acceleration was significantly associated with self-reported instability (Spearman's rho = -0.63, P < .01).

CONCLUSIONS

Data from wearable sensors are a valid measurement for exploring the mechanisms and risks of instability among patients with knee OA.

Association of Varus Knee Thrust During Walking With Worsening Western Ontario and McMaster Universities Osteoarthritis Index Knee Pain: A Prospective Cohort Study

OBJECTIVE

To investigate the 2-year association of varus knee thrust observed during walking to the odds of worsening Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain in older adults with or at risk of osteoarthritis (OA).

METHODS

Video recordings of self-paced walking trials of Multicenter Osteoarthritis Study participants were assessed for the presence of varus thrust at baseline. Knee pain was assessed using the WOMAC questionnaire at baseline and at 2 years. Logistic regression was used to estimate the odds of worsening knee pain (defined as either any increase in WOMAC score or as clinically important worsening), adjusting for age, sex, race, body mass index, clinic site, gait speed, and static knee alignment. Analyses were repeated, stratified by baseline radiographic OA status and among the subset of knees without baseline WOMAC pain.

RESULTS

A total of 1,623 participants contributed 3,204 knees. Varus thrust was observed in 31.5% of knees. Knees with varus thrust had 1.44 times (95% confidence interval [95% CI] 1.19-1.73) the odds of any worsening and 1.37 times (95% CI 1.11-1.69) the odds of clinically important worsening WOMAC pain compared to knees without thrust. Knees with thrust without baseline WOMAC pain had 2.01 times (95% CI 1.47-2.74) the odds of incident total pain.

CONCLUSION

Results indicate that varus thrust is a risk factor for worsening and incident knee pain. Targeting varus thrust through noninvasive therapies could prevent development or worsening of knee pain in older adults with or at risk for knee OA.

Effectiveness of medial-wedge insoles for children with intoeing gait who fall easily

OBJECTIVES

This study aims to investigate the effectiveness of orthosis therapy using a medial-wedge insole (MWI) with a height of 5 mm and an arch support for children with intoeing gait who are prone to falling.

PATIENTS AND METHODS

Between January 1997 and July 2014, a total of 51 children (24 males, 27 females; mean age 5.0 years; range, 3 to 8 years) who were treated for an intoeing gait symptom of easily falling using the MWI (toe-in gait group) were included. The effectiveness of the MWI was evaluated based on the scores reported by children and their parents on a scale. Physical findings of the study group were also compared with a control group consisting of seven healthy children (4 males, 3 females; mean age 5.2 years; range, 3 to 6.2 years). Foot stability with and without MWI were assessed.

RESULTS

The MWI was found to be effective in 80.8% of the toe-in gait group. Bilateral sum of the internal rotation angle of the hip (IRAB) was significantly higher (136±17°) (p=0.007) and bilateral sum of thigh foot angle (TFAB) significantly lower (-27±21°) (p<0.001) before using MWI in the toe-in gait group, compared to the control group. The maximum range of motion of the foot in six children in the toe-in gait group significantly decreased from 14.1±5.0° without MWI to 8.2±3.0° with MWI (p=0.002) in the gait analysis.

CONCLUSION

These study results suggest that MWI is effective in reducing the risk of falling in children with intoeing gait, mainly due to the internal torsion of the tibia or femur. In addition, it appears to be effective in improving the maximum range of motion of the foot.

Temporary postoperative treatment with compartment-unloading knee braces or wedge insoles does not improve clinical outcome after partial meniscectomy

PURPOSE

To investigate whether temporary postoperative compartment-unloading therapy after arthroscopic partial meniscectomy (APM)-with either knee braces or wedge insoles-leads to superior clinical outcome as compared to controls. This difference in clinical outcome was tested in the form of two knee scores, physical activity and general health outcome over the first postoperative year.

METHODS

Sixty-three patients who underwent arthroscopic partial meniscectomy (APM) were randomized to one of the following three groups: 12 weeks postoperative knee compartment-unloading therapy with either a knee brace (brace group) or wedge insoles (insole group) or no specific postoperative therapy (control group). Patient-reported outcome was assessed with the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC Score), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the MARX score (physical activity) and the SF-12 (general health).

RESULTS

Sixty-three patients were available for analysis. Except for the SF-12 mental score, all other scores showed significant improvement over time. With regard to the hypotheses proposed, no significant group * time interactions were observed for any of the outcome parameters. This means that the group (i.e. the type of postoperative treatment) was not related to the degree of improvement of any of the scores.

CONCLUSIONS

It was concluded that 12 weeks of compartment-unloading therapy-with either a knee brace or wedge insoles-is ineffective with regard to clinical outcome after APM. This applies to the knee score outcome, physical activity and general health outcome over the first year following APM.

LEVEL OF EVIDENCE

Randomized controlled trial, Level I.

Varus thrust visualized during gait was associated with inverted foot in patients with knee osteoarthritis: An exploratory study

The foot is speculated to play a role in knee joint kinematics. This exploratory cross-sectional study examined the association between static foot posture and the presence of varus thrust visualized during gait in patients with medial knee osteoarthritis (OA). Patients (n = 88 patients and 134 knees; age, 61-91 years; 68.2% female) with Kellgren/Lawrence (K/L) grade ≥1 in the medial compartment were included in this study and underwent gait observation for varus thrust. These patients' three-dimensional static foot posture while standing was evaluated and their tibiofemoral joint K/L grades and anatomical axis angles were also assessed as covariates. Knees with varus thrust (22 knees, 16.4%) on average had a 4° more inverted calcaneus relative to the floor than those without varus thrust (P < 0.001). A logistic regression analysis showed that an increased calcaneus inversion angle was significantly associated with higher odds of the presence of varus thrust with adjustments for age, sex, body mass index, K/L grade, and anatomical axis angle. The other predictors, such as navicular height, navicular height/foot length, and rearfoot angle relative to the lower leg, were not significantly associated with varus thrust. These results suggest that patients with varus thrust had a different static rearfoot posture as compared with those without varus thrust, a finding that may indicate an important role of static rearfoot posture in the pathogenesis of varus thrust. Furthermore, investigating the potential influence of foot posture on the efficacy of biomechanical interventions, such as lateral wedge insole use, on varus thrust would be of particular interest in the further studies.

Varus thrust in women with early medial knee osteoarthritis and its relation with the external knee adduction moment

BACKGROUND

Varus thrust, defined as an abrupt increase of the knee varus angle during weight-bearing in gait, has been shown to be present in patients with moderate to severe knee osteoarthritis and is considered to be one of the risk factors for progression of symptomatic medial knee osteoarthritis. We evaluated the presence and magnitude of varus thrust and its relation with the Knee Adduction Moment in women with early medial knee osteoarthritis, and compared it to that in a group of controls and in a group of subjects with established medial knee osteoarthritis.

METHODS

Twenty-seven women with early medial knee osteoarthritis, 20 women with established medial knee osteoarthritis and 24 asymptomatic controls were evaluated. Varus thrust was estimated as an increase of the knee varus angle during the weight-bearing phase of gait at self-selected speed, assessed by 3D motion analysis.

FINDINGS

Varus thrust was significantly higher in both early and established osteoarthritis groups compared to the control group (P<0.001), but not different between osteoarthritis groups. While the knee adduction moments were higher than controls only in the established osteoarthritis group, the magnitude of varus thrust was significantly correlated with the second peak knee adduction moment.

INTERPRETATION

Higher varus thrust was found both in early and established stages of knee osteoarthritis, suggesting that problems with dynamic stabilization of the knee are present early in the development of knee osteoarthritis. This highlights the necessity of considering dynamic alignment in rehabilitation already in the early stages of the disease.

Knee joint contact mechanics during downhill gait and its relationship with varus/valgus motion and muscle strength in patients with knee osteoarthritis

OBJECTIVE

The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA).

METHODS

Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed.

RESULTS

Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p < 0.02) and greater heel-strike joint contact point velocities (p < 0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p = 0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p < 0.01) and greater quadriceps and hip abductor muscle weakness (p = 0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p < 0.04) but not with quadriceps or hip abductor strength.

CONCLUSION

Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength.

The dose-response relationship between lateral foot wedging and the reduction of knee adduction moment

BACKGROUND

Lateral foot wedges represent a biomechanical intervention aimed at reducing medial knee loads. However, the effects of varying wedge amounts on biomechanical variables and orthotic comfort have not been systematically studied. Further, arch height may influence the comfort of laterally wedged devices. Therefore, the primary purpose of this study was to examine the effect of incrementally increasing lateral wedge amounts on knee adduction moment parameters and subjective comfort. The secondary purpose was to relate arch height measures to the comfort of the devices.

METHODS

Twenty-five healthy subjects underwent three-dimensional instrumented gait analysis testing using seven inclinations of lateral wedging (0°, 2°, 4°, 6°, 8°, 10°, 12°). Subjects reported comfort level for each orthotic condition. Arch heights were measured in standing and sitting, and rigidity index and stiffness were calculated.

FINDINGS

The knee adduction moment decreased with wedge amounts up to 6°, but more aggressive amounts did not yield additional reductions. Comfort ratings did not change from baseline until wedge amounts exceeded 8°. In addition, arch height measures, arch rigidity index and stiffness did not relate to the comfort of the orthotic device regardless of the wedge amount.

INTERPRETATION

Knee adduction moment decreased with mild wedge amounts while maintaining comfort. Wedge amounts greater than 6° yielded little additional mechanical benefit and amounts greater than 8° compromised comfort. It appears that 4°-6° of lateral wedging are optimal in regard to desirable biomechanical change and comfort level in healthy individuals.

Accelerometer and gyroscope based gait analysis using spectral analysis of patients with osteoarthritis of the knee

[Purpose] A wide variety of accelerometer tools are used to estimate human movement, but there are no adequate data relating to gait symmetry parameters in the context of knee osteoarthritis. This study’s purpose was to evaluate a 3D-kinematic system using body-mounted sensors (gyroscopes and accelerometers) on the trunk and limbs. This is the first study to use spectral analysis for data post processing. [Subjects] Twelve patients with unilateral knee osteoarthritis (OA) (10 male) and seven age-matched controls (6 male) were studied. [Methods] Measurements with 3-D accelerometers and gyroscopes were compared to video analysis with marker positions tracked by a six-camera optoelectronic system (VICON 460, Oxford Metrics). Data were recorded using the 3D-kinematic system. [Results] The results of both gait analysis systems were significantly correlated. Five parameters were significantly different between the knee OA and control groups. To overcome time spent in expensive post-processing routines, spectral analysis was performed for fast differentiation between normal gait and pathological gait signals using the 3D-kinematic system. [Conclusions] The 3D-kinematic system is objective, inexpensive, accurate and portable, and allows long-term recordings in clinical, sport as well as ergonomic or functional capacity evaluation (FCE) settings. For fast post-processing, spectral analysis of the recorded data is recommended.

Comparison the effect of lateral wedge insole and acupuncture in medial compartment knee osteoarthritis: a randomized controlled trial

BACKGROUND

There is lack of well-designed trials evaluating structural benefits of non-pharmacologic therapies in knee osteoarthritis (OA). In this parallel-group randomized controlled trial, we aim to compare the possible advantages of lateral wedge insole and acupuncture in patients with medial knee OA.

METHOD

Patients with grade two or three of medial knee OA were randomly allocated to group one who received an in shoe lateral wedge and group two who underwent acupuncture. We assessed patients' pain, function and knee joint cartilage thickness before and after intervention. Paired t-test and independent samples t-test were used for in group and between group analyses. (

LEVEL OF EVIDENCE

2.)

RESULTS

Twenty patients in each group were recruited in the study. Pain significantly decreased after therapy in both groups one and two (paired t test, P<0.001, 95% CI: 1.62-3.25 and 1.58-3.20 respectively). Function improved in each group (paired t test, P=0.001, 95% CI of 0.94-2.38 in group one and 0.97-2.43 in group two). A non-clinically statistically significant difference regarding the femoral and tibial cartilage thickness was obtained in both groups one (P=0.005, CI: -0.43-0.82 and P=0.037, CI: -0.44-0.80 respectively) and two (P=0.025, CI: -0.45-0.79 and P=0.035, CI: -0.29-0.96 respectively). Between groups analysis showed no significant difference regarding abovementioned measures.

CONCLUSION

Both lateral wedge insole and acupuncture can be effective in the treatment of medial knee osteoarthritis without any superiority of one over the other. Iranian Registry of Clinical Trials: IRCT201201108235N1. URL: http://irct.ir/searchen.php.

Lateral wedge insoles as a conservative treatment for pain in patients with medial knee osteoarthritis: a meta-analysis

IMPORTANCE

There is no consensus regarding the efficacy of lateral wedge insoles as a treatment for pain in medial knee osteoarthritis.

OBJECTIVE

To evaluate whether lateral wedge insoles reduce pain in patients with medial knee osteoarthritis compared with an appropriate control.

DATA SOURCES

Databases searched include the Cochrane Central Register of Controlled Trials, EMBASE, AMED, MEDLINE, CINAHL Plus, ScienceDirect, SCOPUS, Web of Science, and BIOSIS from inception to May 2013, with no limits on study date or language. The metaRegister of Controlled Trials and the NHS Evidence website were also searched.

STUDY SELECTION

Included were randomized trials comparing shoe-based treatments (lateral heel wedge insoles or shoes with variable stiffness soles) aimed at reducing medial knee load, with a neutral or no wedge control condition in patients with painful medial knee osteoarthritis. Studies must have included patient-reported pain as an outcome.

DATA EXTRACTION AND SYNTHESIS

Trial data were extracted independently by 2 researchers using a standardized form. Risk of bias was assessed using the Cochrane Risk of Bias tool by 2 observers. Eligible studies were pooled using a random-effects approach.

MAIN OUTCOME AND MEASURES

Change in self-reported knee pain at follow-up.

RESULTS

Twelve trials met inclusion criteria with a total of 885 participants of whom 502 received lateral wedge treatment. The pooled standardized mean difference (SMD) suggested a favorable association with lateral wedges compared with control (SMD, -0.47; 95% CI, -0.80 to -0.14); however, substantial heterogeneity was present (I2 = 82.7%). This effect size represents an effect of -2.12 points on the 20-point Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scale. Larger trials with a lower risk of bias suggested a null association. Meta-regression analyses showed that higher effect sizes (unstandardized β, 1.07 [95% CI, 0.28 to 1.87] for trials using a no treatment control) were seen in trials using a no wedge treatment control group (n = 4 trials; SMD, -1.20 [95% CI, -2.09 to -0.30]) and lower effect sizes (unstandardized β, 0.26 [95% CI, 0.002 to 0.52] for each bias category deemed low risk) when the study method was deemed at low risk of bias. Among trials in which the control treatment was a neutral insole (n = 7), lateral wedges showed no association (SMD, -0.03 [95% CI, -0.18 to 0.12] on WOMAC; this represents an effect of -0.12 points), and results showed little heterogeneity (I2 = 7.1%).

CONCLUSIONS AND RELEVANCE

Although meta-analytic pooling of all studies showed a statistically significant association between use of lateral wedges and lower pain in medial knee osteoarthritis, restriction of studies to those using a neutral insole comparator did not show a significant or clinically important association. These findings do not support the use of lateral wedges for this indication.

Mechanical effectiveness of lateral foot wedging in medial knee osteoarthritis after 1 year of wear

The use of lateral foot wedging in the management of medial knee osteoarthritis is under scrutiny. Interestingly, there have been minimal efforts to evaluate biomechanical effectiveness with long-term use. Therefore, we aimed to evaluate dynamic knee loading (assessed using the knee adduction moment) and other secondary gait parameters in patients with medial knee osteoarthritis wearing lateral foot wedging at a baseline visit and after 1 year of wear. Three-dimensional gait data were captured in an intervention group of 19 patients with symptomatic medial knee osteoarthritis wearing their prescribed laterally wedged foot orthoses at 0 and 12 months. Wedge amounts were prescribed based on symptom response to a step-down test. A control group of 19 patients wearing prescribed neutral orthoses were also captured at 0 and 12 months. The gait of the intervention group wearing neutral orthoses was additionally captured. Walking speed and shoes were controlled. Analyses of variance were conducted to examine for group-by-time (between the groups in their prescribed orthoses) and condition-by-time (within the intervention group) interactions, main effects, and simple effects. We observed increased knee adduction moments and frontal plane motion over time in the control group but not the intervention group. Further, within the intervention group, the mechanical effectiveness of the lateral wedging did not decrease. In patients with medial knee osteoarthritis, the effects of lateral foot wedging on pathomechanics associated with medial knee osteoarthritis were favorable and sustained over time.

Long-term stress distribution patterns of the ankle joint in varus knee alignment assessed by computed tomography osteoabsorptiometry

PURPOSE

The stress distribution of an ankle under various physiological conditions is important for long-term survival of total ankle arthroplasty. The aim of this study was to measure subchondral bone density across the distal tibial joint surface in patients with malalignment/instability of the lower limb.

METHODS

We evaluated subchondral bone density across the distal tibial joint in patients with malalignment/instability of the knee by computed tomography (CT) osteoabsorptiometry from ten ankles as controls and from 27 ankles with varus deformity/instability of the knee. The quantitative analysis focused on the location of the high-density area at the articular surface, to determine the resultant long-term stress on the ankle joint.

RESULTS

The area of maximum density of subchondral bone was located in the medial part in all subjects. The pattern of maximum density in the anterolateral area showed stepwise increases with the development of varus deformity/instability of the knee.

CONCLUSIONS

Our results should prove helpful for designing new prostheses and determining clinical indications for total ankle arthroplasty.

A quantitative assessment of varus thrust in patients with medial knee osteoarthritis

Varus thrust is an abnormal lateral knee motion frequently seen in patients with medial knee osteoarthritis (OA) during gait. It is a worsening of the alignment in the stance phase of the gait cycle and closely relates to disease progression. In this study, we measured the thrust quantitatively using skin markers and examined the relationship to other static and dynamic parameters. Forty-four knees in 32 patients (mean age, 72years; range, 64-81years) who exhibited the radiographic OA at least grade 2 according to the Kellgren-Lawrence (K-L) scale were enrolled. Gait analysis was performed for each patient to measure the amount of thrust and knee adduction moment. The amounts of thrust in subjects with K-L grades 2 (25 knees), 3 (13 knees), and 4 (6 knees) were 2.4°(±1.3°), 2.8°(±1.4°), and 7.2°(±5.3°), respectively and the knee adduction moments were 3.6(±1.5) %BW⁎Ht, 3.9(±1.2) %BW⁎Ht and 6.9(±2.2%) BW⁎Ht, respectively. The amount of thrust also exhibited significant correlation to static radiographic alignment (R=0.47: 95% confidence interval 0.67-0.21, p=0.0038) and showed greater correlation to the knee adduction moment (R=0.73: 95% confidence interval 0.84-0.55, p<0.001), which has been identified as an important dynamic index of the disease. The amount of thrust, which is able to be measured by simple inexpensive equipment, correlated to static and dynamic parameters and may offer an important clinical index for knee OA.

Effect of center of pressure modulation on knee adduction moment in medial compartment knee osteoarthritis

The knee adduction moment (KAM) provides a major contribution to the elevated load in the medial compartment of the knee. An abnormally high KAM has been linked with the progression of knee osteoarthritis (OA). Footwear-generated biomechanical manipulations reduce the magnitude of this moment by conveying a more laterally shifted trajectory of the foot's center of pressure (COP), reducing the distance between the ground reaction force and the center of the knee joint, thus lowering the magnitude of the torque. We sought to examine the outcome of a COP shift in a cohort of female patients suffering from medial knee OA. Twenty-two female patients suffering from medial compartment knee OA underwent successive gait analysis testing and direct pedobarographic examination of the COP trajectory with a foot-worn biomechanical device allowing controlled manipulation of the COP. Modulation of the COP coronal trajectory from medial to lateral offset resulted in a significant reduction of the KAM. This trend was demonstrated in subjects with mild-to-moderate OA and in patients suffering from severe stages of the disease. Our results indicate that controlled manipulation of knee coronal kinetics in individuals suffering from medial knee OA can be facilitated by customized COP modification.

Biomechanical changes accompanying unilateral and bilateral use of laterally wedged insoles with medial arch supports in patients with medial knee osteoarthritis

BACKGROUND

Laterally wedged insoles have controversial effect in treating medial compartment knee osteoarthritis. This study examined the effects of unilateral and bilateral use of insoles having medial arch supports and of different inclinations on the frontal plane external hip, knee, subtalar moments and pelvic alignment.

METHODS

Kinetic and kinematic gait parameters were collected from 21 patients with primary medial knee osteoarthritis. The insoles' inclinations were 0, 6 and 11°, where each of the 6° and 11° was used once unilaterally and another bilaterally while the 0° was used bilaterally as a control.

FINDINGS

The Multivariate Analysis of Variance revealed significant increase in the external subtalar eversion moment using either of the 6° or 11° laterally wedged vs the 0° non-wedged insole conditions (P=0.003). Moreover, there were significant increases in the external eversion moment using the 11° vs the 6° insole conditions (P<0.05). However, there were no significant differences for the remaining tested variables (P>0.05). The bivariate correlations revealed significant negative correlations between the subtalar eversion and knee adduction moments (r=-0.409, P=0.000) and the subtalar eversion and hip adduction moments (r=-0.226, P=0.049), and positive correlation between the hip and knee adduction moments (r=0.268, P=0.019).

INTERPRETATION

The non-significant reduction in the external knee adduction moment may question the efficacy of using wedged insoles having medial arch supports in treating patients with medial knee osteoarthritis. Additionally, using such insoles did not produce appreciable mechanical effects on remote articulations as the hip and pelvis.

Pain, balance, self-reported function and physical function in individuals with knee osteoarthritis

Disability resulting from knee osteoarthritis (OA) is determined by physiological and functional variables though the interactions between the variables remain unclear and deserve further study. This study's major objective was to explore the relationship between pain, body mass index (BMI), balance, self-report function, and physical function in a cohort who had both unilateral and bilateral knee OA. Fifty-two patients (46 female, 6 male) ranging from 31 to 80 years of age (mean ± SD: 59.0 ± 9.8 years) with radiograph-confirmed OA of the knees participated in this study. Participants' pain intensity, self-reported function, dynamic balance, and physical function performance were measured by using box numerical scale, OA Index of Lequesne, functional reach test, and both stair climbing and timed up-and-go (TUG) tests, respectively. Associations between age, BMI, pain, balance, self-reported function, and physical function performance were explored by univariate and multivariate analyses at α = 0.05. Significant direct correlations were found between physical function performance and self-reported function (r = 0.56, r = 0.01) and age (r = 0.55, p = 0.01) and between self-reported function and age (r = 0.40, p = 0.01) in the cohort with bilateral knee OA. Significant inverse correlation was observed between age and balance (r = -0.58, p = 0.01) in participants with unilateral knee OA. In the regression model for all participants, self-reported function and age accounted for 27.0% of the variance in stair climbing test and 29.0% of the variance in the TUG test. Self-reported function and age are significant predictors of physical function in individuals with knee OA.

Efficacy of knee braces and foot orthoses in conservative management of knee osteoarthritis: a systematic review

A systematic analysis was conducted on the effectiveness of knee braces and foot orthoses in conservative management of knee osteoarthritis. The methodologic quality of the randomized clinical trials, controlled clinical trials, and observational studies were systematically reviewed using the Structured Effectiveness Quality Evaluation Scale. Twenty-five studies met the inclusion criteria. The orthoses used in the studies included Generation II osteoarthritis knee brace, valgus knee braces, functional off-loading knee braces, knee sleeves, lateral-wedged insoles with subtalar strapping, medial-wedged insoles, and specialized footwear. Results suggest that knee braces and foot orthoses are effective in decreasing pain, joint stiffness, and drug dosage. They also improve proprioception, balance, Kellgren/Lawrence grading, and physical function scores in subjects with varus and valgus knee osteoarthritis. Knee braces and foot orthoses could be cautiously considered as conservative management for relief of pain and stiffness and improving physical function for persons with knee osteoarthritis. The conclusions of this review are limited by methodologic considerations like poor quality of trials and heterogeneity of interventions.

Medial knee osteoarthritis treated by insoles or braces: a randomized trial

BACKGROUND

There is controversial evidence regarding whether foot orthoses or knee braces improve pain and function or correct malalignment in selected patients with osteoarthritis (OA) of the medial knee compartment. However, insoles are safe and less costly than knee bracing if they relieve pain or improve function.

QUESTIONS/PURPOSES

We therefore asked whether laterally wedged insoles or valgus braces would reduce pain, enhance functional scores, and correct varus malalignment comparable to knee braces.

PATIENTS AND METHODS

We prospectively enrolled 91 patients with symptomatic medial compartmental knee OA and randomized to treatment with either a 10-mm laterally wedged insole (index group, n = 45) or a valgus brace (control group, n = 46). All patients were assessed at 6 months. The primary outcome measure was pain severity as measured on a visual analog scale. Secondary outcome measures were knee function score using WOMAC and correction of varus alignment on AP whole-leg radiographs taken with the patient in the standing position. Additionally, we compared the percentage of responders according to the OMERACT-OARSI criteria for both groups.

RESULTS

We observed no differences in pain or WOMAC scores between the two groups. Neither device achieved correction of knee varus malalignment in the frontal plane. According to the OMERACT-OARSI criteria, 17% of our patients responded to the allocated intervention. Patients in the insole group complied better with their intervention. Although subgroup analysis results should be translated into practice cautiously, we observed a slightly higher percentage of responders for the insole compared with bracing for patients with mild medial OA.

CONCLUSIONS

Our data suggest a laterally wedged insole may be an alternative to valgus bracing for noninvasively treating symptoms of medial knee OA.

LEVEL OF EVIDENCE

Level I, therapeutic study. See the Guidelines for Authors for a complete description of level of evidence.

Frequency of varus and valgus thrust and factors associated with thrust presence in persons with or at higher risk of developing knee osteoarthritis

OBJECTIVE

Varus thrust observed during gait has been shown to be associated with a 4-fold increase in the risk of medial knee osteoarthritis (OA) progression. Valgus thrust is believed to be less common than varus thrust; the prevalence of each is uncertain. Racial differences in risk factors may help explain variations in the natural history of knee OA. We undertook this study to determine the frequency of varus and valgus thrust in African Americans and Caucasians and to identify factors associated with thrust presence.

METHODS

The Osteoarthritis Initiative cohort includes men and women who have knee OA or are at increased risk of developing it. Trained examiners assessed thrust presence by gait observation. Logistic regression with generalized estimating equations was used to identify factors associated with thrust presence, and odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated.

RESULTS

Compared with Caucasians, African Americans had lower odds of varus thrust, controlling for age, sex, body mass index (BMI), injury, surgery, disease severity, strength, pain, and alignment in persons without knee OA (adjusted OR 0.50 [95% CI 0.36, 0.72]) and in those with knee OA (adjusted OR 0.46 [95% CI 0.34, 0.61]). Also independently associated with varus thrust were age, sex, BMI, disease severity, strength, and alignment. The odds of valgus thrust were greater for African Americans than for Caucasians in persons without knee OA (adjusted OR 1.69 [95% CI 1.02, 2.80]) and in those with knee OA (adjusted OR 1.98 [95% CI 1.35, 2.91]). Also independently associated with valgus thrust were disease severity and malalignment.

CONCLUSION

Compared with Caucasians, African Americans had lower odds of varus thrust and greater odds of valgus thrust. These findings may help explain the difference between these groups in the pattern of OA involvement at the knee.

Periacetabular osteotomy reduces the dynamic instability of dysplastic hips

We compared the dynamic instability of 25 dysplastic hips in 25 patients using triaxial accelerometry before and one year after periacetabular osteotomy. We also evaluated the hips clinically using the Harris hip score and assessed acetabular orientation by radiography before surgery and after one year. The mean overall magnitude of acceleration was significantly reduced from 2.30 m/s(2) (sd 0.57) before operation to 1.55 m/s(2) (sd 0.31) afterwards. The mean Harris hip score improved from 78.08 (47 to 96) to 95.36 points (88 to 100). The radiographic parameters all showed significant improvements. This study suggests that periacetabular osteotomy provides pain relief, improves acetabular cover and reduces the dynamic instability in patients with dysplastic hips.

Advances in insoles and shoes for knee osteoarthritis

PURPOSE OF REVIEW

This review highlights recent research findings, including their clinical application, for insoles and footwear in knee osteoarthritis. In particular, it examines their effect on knee load, osteoarthritis symptoms and disease progression.

RECENT FINDINGS

Increased joint loading increases the risk of osteoarthritis progression, but is amenable to change. Given the prevalence of medial compartment osteoarthritis, insoles and footwear largely aim to reduce the knee adduction moment, an indicator of medial compartment load. Lateral wedged insoles can reduce this moment but do not appear to slow disease progression. Although nonexperimental and quasiexperimental studies report favourable effects of lateral wedges on symptoms, clinical trials have not been confirmatory. Medial wedged insoles show promise in relieving symptoms of lateral compartment disease. Walking in shoes increases joint load compared with walking in barefeet. Shoes with a flat or low heel and that are flexible rather than stabilizing may be optimal; however, effects of off-the-shelf shoes on osteoarthritis symptoms are unknown. Promising shoe modifications include shoes that promote foot mobility and those with variable stiffness or laterally wedged soles.

SUMMARY

Insoles and footwear offer great potential, as simple, inexpensive-treatment strategies for knee osteoarthritis. Further research is needed to evaluate efficacy and to determine which patient subgroups are most responsive.

The biomechanics of osteoarthritis: implications for therapy

The pathophysiology of osteoarthritis (OA) has been extensively studied. However, the basic approach to therapy, which consists of pain relief and maintenance of function, has not changed for decades. At present, there are no nonsurgical methods that clearly interfere with the natural history of OA or provide prolonged pain palliation. Much of OA disease progression is mediated by aberrant biomechanical forces or through pathologic responses to those forces. As understanding of these mechanisms improves, novel therapeutic approaches are being studied that may provide prolonged reductions in loading of OA joints. These new therapies may ultimately be shown to retard disease progression and palliate pain. This article reviews some of these strategies.

Varus alignment leads to increased forces in the anterior cruciate ligament

BACKGROUND

Varus thrust of the knee is a dynamic increase of an often preexisting varus angle and it is suspected to be a major reason for failure of anterior cruciate ligament reconstructions. However, it is not known if a direct relationship exists between varus thrust and forces in the anterior cruciate ligament.

HYPOTHESIS

Forces in the anterior cruciate ligament increase with increasing varus alignment, and consequently an anterior cruciate ligament deficiency in a varus-aligned leg leads to more lateral tibiofemoral joint opening.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six human cadaver legs were axially loaded with 3 different weightbearing lines--a neutral weightbearing line, a weightbearing line that passes through the middle of the medial tibial plateau (50% varus), and a line passing the edge of the medial tibial plateau (100% varus)--that were used to create a varus moment. The resulting lateral tibiofemoral joint opening and corresponding anterior cruciate ligament tension were measured. The tests were repeated with and without the anterior cruciate ligament in place.

RESULTS

In the neutral aligned legs, there was no apparent lateral joint opening, and no anterior cruciate ligament tension change was noted. The lateral joint opening increased when the weightbearing line increased from 0% to 50% to 100%. The lateral joint opening was significantly higher in 10 degrees of knee flexion compared with knee extension. In the 100% varus weightbearing line, the anterior cruciate ligament tension was significantly higher (53.9 N) compared with neutral (31 N) or the 50% weightbearing line (37.9 N). A thrust could only be observed in the 100% weightbearing line tests. In the absence of an anterior cruciate ligament, there was more lateral joint opening, although this was only significant in the 100% weightbearing line.

CONCLUSION

There is a direct relationship between varus alignment and anterior cruciate ligament tension. In the absence of an anterior cruciate ligament, the amount of lateral opening tends to increase. With increasing lateral opening, a thrust can sometimes be experimentally observed.

CLINICAL RELEVANCE

A varus alignment in an anterior cruciate ligament-deficient knee does not necessarily lead to a varus thrust and therefore does not always need operative varus alignment correction. However, in an unstable anterior cruciate ligament-deficient knee with a varus thrust, it might be safer to perform a high valgus tibial osteotomy to minimize the risk of an anterior cruciate ligament reconstruction failure.

Walking shoes and laterally wedged orthoses in the clinical management of medial tibiofemoral osteoarthritis: a one-year prospective controlled trial

The purpose of the study was to examine the clinical efficacy of individually prescribed laterally wedged orthoses and walking shoes in the treatment of medial knee osteoarthritis using a prospective, single-blind, block-randomized controlled design. Sixty-six subjects (29 males, 37 females, mean age 62.4 years, mean BMI 33.0 kg/m(2)) were block-randomized to a lateral wedge (treatment) or neutral (control) orthotic group. Both groups were issued a standardized walking shoe for use with the orthoses. Primary outcome measures included the pain, stiffness, and functional limitations subscales of the Western Ontario and McMaster Universities index. Secondary outcome measures included the 6-minute walk distance and pain change, and stair negotiation time and pain change. A significant interaction (p=0.039) favoring the treatment group was observed for pain change during the 6-minute walk. The treatment group demonstrated significant improvements at both 1 month (p<0.001) and 1 year (p<0.001) compared to baseline. The control group only demonstrated significant improvements at 1 year (p=0.017). No other interactions were observed. Both groups were improved at each follow-up in the WOMAC subscales for pain (p<0.001), stiffness (p<0.001), and physical function (p<0.001). Both groups also improved in 6-minute walk test distance (p<0.001), stair negotiation test time (p=0.004), and stair negotiation test pain change (p<0.001). The results suggest that both neutral and laterally wedged orthoses may be beneficial in the management of medial knee osteoarthritis when used with walking shoes. However, the addition of lateral wedging was associated with early improvements in 6-minute walk test pain change not seen in the control group.

The responsiveness of three-dimensional knee accelerations used as an estimation of knee instability and loading transmission during gait in osteoarthritis patient's follow-up

OBJECTIVE

Knee instability and joint loading transmission are two important biomechanical factors in subjects with knee osteoarthritis (OA). However, the relationship between these factors in a rehabilitation treatment remains unclear. The purpose of this study is to determine the responsiveness of a new three-dimensional (3D) acceleration method used as an estimation of knee instability and joint loading transmission during gait in OA subjects after a rehabilitation treatment.

METHOD

Twenty-four subjects with medial knee OA were included in this study. They had clinical and gait evaluations before and after 12 weeks of treatment. 3D linear knee accelerations, quadriceps and hamstring isometric strength and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) pain were quantified, and compared between both evaluations. Nine asymptomatic subjects participated in this study for gait comparison.

RESULTS

A significant reduction of the anterior posterior (AP) knee acceleration peak (P=0.02) had been detected after the treatment. No difference for both distal and lateral knee accelerations peak was found. A significant increase in quadriceps (P<0.001) and hamstring (P=0.006) strength was seen after treatment. The WOMAC of pain had shown significant reduction after the treatment (P<0.001).

CONCLUSION

The present study demonstrates that the estimation of knee acceleration parameters is sensitive to changes in knee OA gait after a rehabilitation treatment. This study also indicates that a treatment of 3 months which combines therapeutic and exercises program could have benefits on knee OA by increasing AP knee stability and stabilize joint loading transmission during gait.

Knee osteoarthritis: primary care using noninvasive devices and biomechanical principles

Osteoarthritis (OA) is an epidemic for which there is no known cure. There is enormous popular demand for noninvasive and nonpharmacologic therapies for OA, and there is a pressing need for primary care physicians to respond by updating their pattern of practice. Despite increasing concern about the capacity of our health care system to meet rising demands, routine primary care for knee OA has changed little over several decades. This article introduces physicians to many of the most important noninvasive devices used in the conservative management of symptomatic knee OA.

Effectiveness of medial-wedge insole treatment for valgus knee osteoarthritis

OBJECTIVE

To assess the efficacy of medial-wedge insoles in valgus knee osteoarthritis (OA).

METHODS

Thirty consecutive women with valgus-deformity knee OA > or = 8 degrees were randomized into 2 groups: medial insole (insoles with 8-mm medial elevation at the rearfoot [n = 16]) and neutral insole (similar insole without elevation [n = 14]). Both groups also wore ankle supports. A blinded examiner assessed pain on movement, at rest, and at night with a visual analog scale (VAS), the Lequesne index, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index. Femorotibial, talocalcaneal, and talar tilt angles were evaluated at baseline and after 8 weeks of insole use.

RESULTS

Significant reductions in the medial insole group were observed for pain on movement (mean +/- SD VAS pre- and postintervention 8.1 +/- 1.5 versus 4.2 +/- 2.4; P = 0.001), at rest (5.1 +/- 2.3 versus 2.7 +/- 2.4; P = 0.002), and at night (6.1 +/- 2.7 versus 3.1 +/- 2.1; P = 0.001). In addition, a decrease in Lequesne (14.7 +/- 3.4 versus 9.6 +/- 3.8; P = 0.001) and WOMAC scores (74.1 +/- 14.2 versus 56.1 +/- 14.9; P = 0.001) was observed for the medial insole group. In the neutral insole group, a significant reduction was observed only for night pain (mean +/- SD VAS pre- and postintervention 5.8 +/- 2.4 versus 4.6 +/- 2.4; P = 0.019). An increase in femorotibial angle (169.0 +/- 3.4 versus 170.8 +/- 3.7; P = 0.001) occurred only in the medial insole group. Moreover, the difference in measured femorotibial angles pre- and postintervention was 1.84 +/- 1.42 versus -0.18 +/- 0.67 (P < 0.001) for the medial and neutral insole groups.

CONCLUSION

The use of medial-wedge insoles was highly effective in reducing pain at rest and on movement and promoted a functional improvement of valgus knee OA.

New accelerometric method to discriminate between asymptomatic subjects and patients with medial knee osteoarthritis during 3-d gait

This study presents a new method to estimate 3-D linear accelerations at tibial and femoral functional coordinate systems. The method combines the use of 3-D accelerometers, 3-D gyroscopes and reflective markers rigidly fixed on an exoskeleton and, a functional postural calibration method. Marker positions were tracked by a six-camera optoelectronic system (VICON 460, Oxford Metrics). The purpose of this study was to determine if this method could discriminate between medial osteoarthritic and asymptomatic knees during gait. Nine patients with osteoarthritic knees and nine asymptomatic control subjects were included in this study. Eighteen parameters representing maximal, minimal, and range of acceleration values were extracted during the loading and preswing to mid-swing phase periods, and were compared in both groups. Results show good discriminative capacity of the new method. Eight parameters were significantly different between both groups. The proposed method has the potential to be used in comprehending and monitoring gait strategy in patients with osteoarthritic knee.

Lateral wedges in knee osteoarthritis: what are their immediate clinical and biomechanical effects and can these predict a three-month clinical outcome?

OBJECTIVE

To assess immediate effects of laterally wedged insoles on walking pain, external knee adduction moment, and static alignment, and whether these immediate effects together with age, body mass index, and disease severity predict clinical outcome after 3 months of wearing insoles in medial knee osteoarthritis.

METHODS

Forty volunteers (mean age 64.7 years, 16 men) were tested in random order with and without a pair of 5 degrees full-length lateral wedges. Immediate changes in static alignment were measured via radiographic mechanical axis and changes in adduction moment via 3-dimensional gait analysis. After 3 months of treatment with insoles, changes in pain and physical functioning were assessed via the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and patient-perceived global change scores.

RESULTS

Reductions in the adduction moment occurred with insoles (first peak mean [95% confidence intervals (95% CI)] -0.22 [-0.28, -0.15] Nm/body weight x height %), accompanied by a reduction in walking pain of approximately 24% (mean [95% CI] -1.0 [-4.0, 2.0]). Insoles had no mean effect on static alignment. Mean improvement in WOMAC pain (P = 0.004) and physical functioning (mean [95% CI] -6 [-11, -1]) was observed at 3 months, with 25 (69%) and 26 (72%) of 36 individuals reporting global improvement in pain and functioning, respectively. Regression analyses demonstrated that disease severity, baseline functioning, and magnitude of immediate change in walking pain and the first peak adduction moment with insoles were predictive of clinical outcome at 3 months.

CONCLUSION

Lateral wedges immediately reduced knee adduction moment and walking pain but had no effect on static alignment. Although some parameters predicted clinical outcome, these explained only one-third of the variance, suggesting that other unknown factors are also important.

OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines

PURPOSE

To develop concise, patient-focussed, up to date, evidence-based, expert consensus recommendations for the management of hip and knee osteoarthritis (OA), which are adaptable and designed to assist physicians and allied health care professionals in general and specialist practise throughout the world.

METHODS

Sixteen experts from four medical disciplines (primary care, rheumatology, orthopaedics and evidence-based medicine), two continents and six countries (USA, UK, France, Netherlands, Sweden and Canada) formed the guidelines development team. A systematic review of existing guidelines for the management of hip and knee OA published between 1945 and January 2006 was undertaken using the validated appraisal of guidelines research and evaluation (AGREE) instrument. A core set of management modalities was generated based on the agreement between guidelines. Evidence before 2002 was based on a systematic review conducted by European League Against Rheumatism and evidence after 2002 was updated using MEDLINE, EMBASE, CINAHL, AMED, the Cochrane Library and HTA reports. The quality of evidence was evaluated, and where possible, effect size (ES), number needed to treat, relative risk or odds ratio and cost per quality-adjusted life years gained were estimated. Consensus recommendations were produced following a Delphi exercise and the strength of recommendation (SOR) for propositions relating to each modality was determined using a visual analogue scale.

RESULTS

Twenty-three treatment guidelines for the management of hip and knee OA were identified from the literature search, including six opinion-based, five evidence-based and 12 based on both expert opinion and research evidence. Twenty out of 51 treatment modalities addressed by these guidelines were universally recommended. ES for pain relief varied from treatment to treatment. Overall there was no statistically significant difference between non-pharmacological therapies [0.25, 95% confidence interval (CI) 0.16, 0.34] and pharmacological therapies (ES=0.39, 95% CI 0.31, 0.47). Following feedback from Osteoarthritis Research International members on the draft guidelines and six Delphi rounds consensus was reached on 25 carefully worded recommendations. Optimal management of patients with OA hip or knee requires a combination of non-pharmacological and pharmacological modalities of therapy. Recommendations cover the use of 12 non-pharmacological modalities: education and self-management, regular telephone contact, referral to a physical therapist, aerobic, muscle strengthening and water-based exercises, weight reduction, walking aids, knee braces, footwear and insoles, thermal modalities, transcutaneous electrical nerve stimulation and acupuncture. Eight recommendations cover pharmacological modalities of treatment including acetaminophen, cyclooxygenase-2 (COX-2) non-selective and selective oral non-steroidal anti-inflammatory drugs (NSAIDs), topical NSAIDs and capsaicin, intra-articular injections of corticosteroids and hyaluronates, glucosamine and/or chondroitin sulphate for symptom relief; glucosamine sulphate, chondroitin sulphate and diacerein for possible structure-modifying effects and the use of opioid analgesics for the treatment of refractory pain. There are recommendations covering five surgical modalities: total joint replacements, unicompartmental knee replacement, osteotomy and joint preserving surgical procedures; joint lavage and arthroscopic debridement in knee OA, and joint fusion as a salvage procedure when joint replacement had failed. Strengths of recommendation and 95% CIs are provided.

CONCLUSION

Twenty-five carefully worded recommendations have been generated based on a critical appraisal of existing guidelines, a systematic review of research evidence and the consensus opinions of an international, multidisciplinary group of experts. The recommendations may be adapted for use in different countries or regions according to the availability of treatment modalities and SOR for each modality of therapy. These recommendations will be revised regularly following systematic review of new research evidence as this becomes available.

Evaluation of dynamic instability of the dysplastic hip with use of triaxial accelerometry

BACKGROUND

Dysfunction of the hip secondary to dysplasia is a complex problem that includes excessive stresses on the articular cartilage, dynamic hip instability, and muscular fatigue, eventually leading to degenerative arthritis if left uncorrected. Mechanical stress on the dysplastic hip has been widely described, but dynamic instability requires further evaluation. The purpose of this study was to investigate dynamic instability of the dysplastic hip with use of triaxial accelerometry.

METHODS

We evaluated forty-eight hips of twenty-four patients with unilateral hip dysplasia (a center-edge angle of <25 degrees ). All contralateral hips were disease-free with normal radiographic findings. An accelerometer was used to record triaxial acceleration while the patient was walking (x-axis: superoinferior direction, y-axis: anteroposterior direction, and z-axis: mediolateral direction). Sensors were attached to the skin, with adhesive tape, over the greater trochanter and the anterior superior iliac spine bilaterally. The time of heel-strike was confirmed visually and by superoinferior acceleration. The averages of the peak values of the middle three gait cycles were used for data analysis. The overall magnitude of acceleration was calculated to evaluate hip instability. The overall magnitudes of acceleration of the dysplastic and contralateral, normal hips were compared with the radiographic data.

RESULTS

The three directions of acceleration were the same in all cases. The overall magnitude of acceleration of the dysplastic hips was significantly larger than that of the contralateral, normal hips (p < 0.0001). There was a negative correlation between the overall magnitude of acceleration and both the center-edge angle and the acetabular head index, and there was a positive correlation between the overall magnitude of acceleration and both the acetabular roof angle and the Sharp angle.

CONCLUSIONS

Hip instability is increased in proportion to the degree of dysplasia. Triaxial accelerometry is helpful in the evaluation of dynamic instability of the dysplastic hip. The center-edge angle can be used as an indicator of hip instability.