Six‐week gait retraining program reduces knee adduction moment,reduces pain,and improves function for individuals with medial compartment knee osteoarthritis

This study examined the influence of a 6‐week gait retraining program on the knee adduction moment (KAM) and knee pain and function. Ten subjects with medial compartment knee osteoarthritis and self‐reported knee pain participated in weekly gait retraining sessions over 6 weeks. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and a 10‐point visual‐analog pain scale score were measured at baseline, post‐training (end of 6 weeks), and 1 month after training ended. Gait retraining reduced the first peak KAM by 20% (p < 0.01) post‐training as a result of a 7° decrease in foot progression angle (i.e., increased internal foot rotation), compared to baseline (p < 0.01). WOMAC pain and function scores were improved at post‐training by 29% and 32%, respectively (p < 0.05) and visual‐analog pain scale scores improved by two points (p < 0.05). Changes in WOMAC pain and function were approximately 75% larger than the expected placebo effect (p < 0.05). Changes in KAM, foot progression angle, WOMAC pain and function, and visual‐analog pain score were retained 1 month after the end of the 6‐week training period (p < 0.05). These results show that a 6‐week gait retraining program can reduce the KAM and improve symptoms for individuals with medial compartment knee osteoarthritis and knee pain. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1020–1025, 2013     

Effect of variable-stiffness walking shoes on knee adduction moment, pain, and function in subjects with medial compartment knee osteoarthritis after 1 year

This study investigated the load‐modifying and clinical efficacy of variable‐stiffness shoes after 12 months in subjects with medial compartment knee osteoarthritis. Subjects who completed a prior 6‐month study were asked to wear their assigned constant‐stiffness control or variable‐stiffness intervention shoes during the remainder of the study. Changes in peak knee adduction moment, total Western Ontario and McMaster Universities (WOMAC), and WOMAC pain scores were assessed. Seventy‐nine subjects were enrolled, and 55 completed the trial. Using an intention‐to‐treat analysis, the variable‐stiffness shoes reduced the within‐day peak knee adduction moment (?5.5%, p < 0.001) in the intervention subjects, while the constant‐stiffness shoes increased the peak knee adduction moment in the control subjects (+3.1%, p = 0.015) at the 12‐month visit. WOMAC pain and total scores for the intervention group were significantly reduced from baseline to 12 months (?32%, p = 0.002 and ?35%, p = 0.007, respectively). The control group had a reduction of 27% in WOMAC pain score (p = 0.04) and no significant reduction in total WOMAC score. Reductions in WOMAC pain and total scores were similar between groups (p = 0.8 and p = 0.47, respectively). In the intervention group, reductions in adduction moment were related to improvements in pain and function (R² = 0.11, p = 0.04). Analysis by disease severity revealed greater efficacy in adduction moment reduction in the less severe intervention group. While the long‐term effects of the intervention shoes on pain and function did not differ from control, the data suggest wearing the intervention shoe reduces the within‐day adduction moment after long‐term wear, and thus should reduce loading on the affected medial compartment of the knee. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:514–521, 2012     

Effects of lateral‐offset sole shoes on knee adduction moment in women with medial compartment knee osteoarthritis

This study aimed to determine the impact of wearing a lateral‐offset sole shoe (LOSS) on knee adduction moment (KAM) in patients with medial knee osteoarthritis (OA). From December 2012 to November 2016, patients with medial knee OA were recruited. Ninety‐three knees (50 left, 43 right) of 93 female patients were analyzed. The first peak KAMs were measured with patients (i) walking barefoot; (ii) walking in conventional shoes; and (iii) walking in LOSSs. The patients had grade 1 (n = 19), grade 2 (n = 49), grade 3 (n = 20), and grade 4 (n = 5) knee OA. First peak KAMs differed significantly in all three conditions (p = 0.031). In the post hoc analysis, first peak KAMs were significantly lower during LOSS walking than during conventional shoe walking (p = 0.001), but there were no differences in peak KAMs between barefoot and LOSS walking (p = 0.784). In the subgroup analysis, patients with grades 2 and 3 OA showed significantly lower first peak KAMs during LOSS walking than during conventional shoe walking (p = 0.029 and p = 0.011, respectively). Both the peak eversion ankle angle and moment of barefoot walking showed a significant increase compared with LOSS and conventional shoe walking, while there was no significant difference between LOSS and conventional shoe walking (p = 0.612 and p = 0.197, respectively). Our results suggest that LOSS wearing caused significant KAM reductions compared with conventional shoe wearing. Since LOSS wearing does not cause changes in the peak eversion ankle angle and moment during the load response, it may be an effective method to reduce the KAM in women with knee OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1694–1700, 2018.

     

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. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1668–1674, 2011     

The lateral wedged insole with subtalar strapping significantly reduces dynamic knee load in the medial compartment gait analysis on patients with medial knee osteoarthritis

OBJECTIVE: Two lateral wedged insoles were compared: one with, and the other without, subtalar strapping. METHODS: Twenty-one patients (age 58-83, mean 72) with medial knee osteoarthritis (OA) were enrolled. Thirty-seven knees in the patients were divided into three groups based on the Kellgren and Lawrence OA grading system; grades 2 (cases=20), 3 (cases=11), and 4 (cases=6). The subjects were tested during walking barefoot and during walking with a silicon rubber lateral wedged insole with elevation of 10 mm attached to a barefoot. Gait analysis was performed on a 10 m walkway for each subject under three different walking conditions; barefoot, wearing a conventional insole, and a subtalar strapping insole. Peak knee varus moment during gait was measured under each condition, and compared between the three conditions and between the OA grades. RESULTS: On the whole (cases=37), the peak varus moment was significantly reduced by wearing either of the insoles, compared to walking barefoot. The reduction was more obvious with the strapping insole (-13%, P<0.01), compared with the conventional insole (-8%, P<0.05). In moderate OA patients (grades 2 and 3), the moments were significantly lower with the strapping insole, compared with the conventional insole (P=0.0048 and 0.005, respectively). However, no significant difference was detected in severe OA patients (grade 4) between the two types of insoles (P=0.4). CONCLUSIONS: Both lateral wedged insoles significantly reduced the peak medial compartment load during gait. The subtalar strapping insole had a greater effect than the conventional insole, particularly in patients with moderate medial knee OA.     

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

OBJECTIVE: Patients with medial compartment knee osteoarthritis (OA) adopt an abnormal gait pattern, and often develop frontal plane laxity at the knee. The purpose of this study was to quantify the extent of frontal plane knee joint laxity in patients with medial knee OA and genu varum and to assess the effect of joint laxity on knee joint kinetics, kinematics and muscle activity during gait. DESIGN: Twelve subjects with genu varum and medial compartment knee osteoarthritis (OA group) and 12 age-matched uninjured subjects underwent stress radiography to determine the presence and magnitude of frontal plane laxity. All subjects also went through gait analysis with surface electromyography of the medial and lateral quadriceps, hamstrings, and gastrocnemius to calculate knee joint kinematics and kinetics and co-contraction levels during gait. RESULTS: The OA group showed significantly greater knee instability (P = 0.002), medial joint laxity (P = 0.001), greater medial quadriceps-medial gastrocnemius (VMMG) co-contraction (P = 0.043), and greater knee adduction moments (P = 0.019) than the control group. Medial joint laxity contributed significantly to the variance in both VMMG and the knee adduction moment during early stance. CONCLUSION: The presence of medial laxity in patients with knee OA is likely contributing to the altered gait patterns observed in those with medial knee OA. Greater medial co-contraction and knee adduction moments bodes poorly for the long-term integrity of the articular cartilage, suggesting that medial joint laxity should be a focus of interventions aimed at slowing the progression of disease in individuals with medial compartment knee OA.     

In healthy subjects without knee osteoarthritis, the peak knee adduction moment influences the acute effect of shoe interventions designed to reduce medial compartment knee load.

The purpose of this study was to evaluate shoe sole material stiffness changes and angle changes that are intended to reduce the peak knee adduction moment during walking. Fourteen physically active adults were tested wearing their personal shoes (control) and five intervention pairs, two with stiffness variations, two with angle variations, and a placebo shoe. The intervention shoes were evaluated based on how much they reduced the peak knee adduction moment compared to the control shoe. An ANOVA test was used to detect differences between interventions. Linear regression analysis was used to determine a relationship between the magnitude of the knee adduction moment prior to intervention and the effectiveness of the intervention in reducing the peak knee adduction moment. Peak knee adduction moments were reduced for the altered stiffness and altered angle shoes (p < 0.010), but not for the placebo shoe (p = 0.363). Additionally, linear regression analysis showed that subjects with higher knee adduction moments prior to intervention had larger reductions in the peak knee adduction moment (p < 0.010). These results demonstrate that shoe sole stiffness and angle interventions can be used to reduce the peak knee adduction moment and that subjects with initially higher peak knee adduction moments have higher reductions in their peak knee adduction moments.     

Muscles that do not cross the knee contribute to the knee adduction moment and tibiofemoral compartment loading during gait

The aims of this study were to evaluate and explain the individual muscle contributions to the medial and lateral knee compartment forces during gait, and to determine whether these quantities could be inferred from their contributions to the external knee adduction moment. Gait data from eight healthy male subjects were used to compute each individual muscle contribution to the external knee adduction moment, the net tibiofemoral joint reaction force, and reaction moment. The individual muscle contributions to the medial and lateral compartment forces were then found using a least‐squares approach. While knee‐spanning muscles were the primary contributors, non‐knee‐spanning muscles (e.g., the gluteus medius) also contributed substantially to the medial compartment compressive force. Furthermore, knee‐spanning muscles tended to compress both compartments, while most non‐knee‐spanning muscles tended to compress the medial compartment but unload the lateral compartment. Muscle contributions to the external knee adduction moment, particularly those from knee‐spanning muscles, did not accurately reflect their tendencies to compress or unload the medial compartment. This finding may further explain why gait modifications may reduce the knee adduction moment without necessarily decreasing the medial compartment force. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1586–1595, 2012     

Changes in the total knee joint moment in patients with medial compartment knee osteoarthritis over 5 years

Progression of medial compartment knee osteoarthritis (OA) has been associated with repetitive mechanical loading during walking, often characterized by the peak knee adduction (KAM) and knee flexion moments (KFM). However, the relative contributions of these components to the knee total joint moment (TJM) can change as the disease progresses since KAM and KFM are influenced by different factors that change over time. This study tested the hypothesis that the relative contributions of KAM, KFM, and the rotational moment (KRM) to the TJM change over time in subjects with medial compartment knee OA. Patients with medial compartment knee OA (n = 19) were tested walking at their self‐selected speed at baseline and a 5‐year follow‐up. For each frame during stance, the TJM was calculated using the KAM, KFM, and KRM. The peaks of the TJM and the relative contributions of the moment components at the time of the peaks of the TJM were tested for changes between baseline and follow‐up. The percent contribution of KFM to the first peak of the TJM (TJM1) significantly decreased (p < 0.001) and the percent contribution of KAM to TJM1 significantly increased (p < 0.001), while the magnitude of the TJM1 did not significantly change over the 5‐year follow‐up. These gait changes with disease progression appear to maintain a constant TJM1, but the transition from a KFM to a KAM dominance appears to reflect gait changes associated with progressing OA and pain. Thus, the TJM and its component analysis captures a comprehensive metric for total loading on the knee over time. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. 36:2373–2379, 2018.

     

The knee adduction moment during gait in subjects with knee osteoarthritis is more closely correlated with static alignment than radiographic disease severity, toe out angle and pain.

This study tested whether the peak external knee adduction moments during walking in subjects with knee osteoarthritis (OA) were correlated with the mechanical axis of the leg, radiographic measures of OA severity, toe out angle or clinical assessments of pain, stiffness or function. Gait analysis was performed on 62 subjects with knee OA and 49 asymptomatic control subjects (normal subjects). The subjects with OA walked with a greater than normal peak adduction moment during early stance (p = 0.027). In the OA group, the mechanical axis was the best single predictor of the peak adduction moment during both early and late stance (R = 0.74, p < 0.001). The radiographic measures of OA severity in the medial compartment were also predictive of both peak adduction moments (R = 0.43 to 0.48, p < 0.001) along with the sum of the WOMAC subscales (R = -0.33 to -0.31, p < 0.017). The toe out angle was predictive of the peak adduction moment only during late stance (R = -0.45, p < 0.001). Once mechanical axis was accounted for, other factors only increased the ability to predict the peak knee adduction moments by 10 18%. While the mechanical axis was indicative of the peak adduction moments, it only accounted for about 50% of its variation, emphasizing the need for a dynamic evaluation of the knee joint loading environment. Understanding which clinical measures of OA are most closely associated with the dynamic knee joint loads may ultimately result in a better understanding of the disease process and the development of therapeutic interventions.     

联合关节镜与常规单髁置换治疗膝内侧室骨关节炎的比较

[目的]比较联合关节镜与常规单髁置换治疗膝内侧骨关节炎的临床疗效。[方法] 2013年9月～2017年6月就诊本科准备行单髁置换术的患者83例(94膝),随机分成两组。其中,联合组49膝行关节镜联合单髁置换术,常规组45膝行常规单髁置换术。记录围手术期资料,采用关节活动度(ROM),美国膝关节协会评分(KSS),西大略和麦克马斯特大学骨关节指数(WOMAC),膝关节视觉模拟评分(VAS)评定临床效果。[结果]联合组有1膝镜下外侧间室局部软骨病变为Outerbridge IV级,改行全膝关节置换术,余82例(93膝)行单髁置换术。联合组手术时间显著长于常规组,差异有统计学意义(P0.05),但两组术中出血量、住院天数的差异无统计学意义(P0.05),随访时间12～45个月,平均(30.32±10.51)个月,与术前相比较,末次随访时两组ROM、KSS、WOMAC和VAS评分均显著改善(P0.05)。末次随访时,联合组ROM、WOMAC和VAS优于常规组,差异均有统计学意义(P0.05),但两组间KSS评分差异无统计学意义(P0.05)。至末次随访,两组患者均未发生关节感染、假体松动等并发症。[结论]尽管关节镜联合单髁置换增加了手术时间,但能更准确选择手术适应证,并改进临床效果。     

Bone mineral density in the proximal tibia varies as a function of static alignment and knee adduction angular momentum in individuals with medial knee osteoarthritis

Based on the premise that bone mass and bone geometry are related to load history and that subchondral bone may play a role in osteoarthritis (OA), we sought to determine if static and dynamic markers of knee joint loads explain variance in the medial-to-lateral ratio of proximal tibial bone mineral density (BMD) in subjects with mild and moderate medial knee OA. We utilized two surrogate markers of dynamic load, the peak knee adduction moment and the knee adduction angular momentum, the latter being the time integral of the frontal plane knee joint moment. BMD for medial and lateral regions of the proximal tibial plateau and one distal region in the tibial shaft was measured in 84 symptomatic subjects with Kellgren and Lawrence radiographic OA grades of 2 or 3. Utilizing gait analysis, the peak knee adduction moment (the external adduction moment of greatest magnitude) and the time integral of the frontal plane knee joint moment (the angular momentum) over the entire stance phase as well as for each of the four subdivisions of stance were calculated. The BMD ratio was not significantly different in grade 2 (1.32 +/- 0.27) and grade 3 knees (1.47 +/- 0.40) (P = 0.215). BMD of the tibial shaft was not correlated with any loading parameter or static alignment. Of all the surrogate gait markers of dynamic load, the knee adduction angular momentum in terminal stance explained the most variance (20%) in the medial-to-lateral BMD ratio (adjusted r(2) = 0.196, P < 0.001). The knee adduction angular momentum for the entire stance phase explained 18% of the variance in the BMD ratio (adjusted r(2) = 0.178, P < 0.001), 10% more variance than explained by the overall peak knee adduction moment (adjusted r(2) = 0.081, P < 0.001). 18% of the variance in the BMD ratio was also explained by the knee alignment angle (adjusted r(2) = 0.183, P < 0.001), and the total explanatory power was increased to 22% when the knee adduction angular momentum in terminal stance was added (change in r(2) = 0.041, P < 0.05, total adjusted r(2) = 0.215, P < 0.001). The BMD ratio and its relationship to dynamic and static markers of loading were independent of height, weight, and the body mass index, demonstrating that both dynamic markers of knee loading as well as knee alignment explained variance in the tibial BMD ratio independent of body size.     

Effects of active feedback gait retraining to produce a medial weight transfer at the foot in subjects with symptomatic medial knee osteoarthritis

This study aimed to determine if active feedback gait retraining to produce a medial weight transfer at the foot significantly reduces the knee adduction moment in subjects with medial compartment knee osteoarthritis. Secondarily, changes in peak knee flexion moment, frontal plane knee and ankle kinematics, and center of pressure were investigated. Ten individuals with medial compartment knee osteoarthritis (9 males; age: 65.3 ± 9.8 years; BMI: 27.8 ± 3.0 kg/m²) were tested at self‐selected normal and fast speeds in two conditions: Intervention, with an active feedback device attached to the shoe of their more affected leg, and control, with the device de‐activated. Kinematics and kinetics were assessed using a motion capture system and force plate. The first peak, second peak, and impulse of the knee adduction moment were significantly reduced by 6.0%, 13.9%, and 9.2%, respectively, at normal speed, with reductions of 10.7% and 8.6% in first peak and impulse at fast speed, respectively, with the active feedback system, with no significant effect on the peak knee flexion moment. Significant reductions in peak varus knee angle and medialized center of pressure in the first half of stance were observed, with reductions in peak varus knee angle associated with reductions in the knee adduction moment. This study demonstrated that active feedback to produce a medial weight‐bearing shift at the foot reduces the peaks and impulse of the knee adduction moment in patients with medial compartment knee osteoarthritis. Future research should determine the long‐term effect of the active feedback intervention on joint loading, pain, and function. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2251–2259, 2017.

     

Changes in knee adduction moment,pain, and functionality with a variable‐stiffness walking shoe after 6 months

This study tested the effects of variable‐stiffness shoes on knee adduction moment, pain, and function in subjects with symptoms of medial compartment knee osteoarthritis over 6 months. Patients were randomly and blindly assigned to a variable‐stiffness intervention or constant‐stiffness control shoe. The Western Ontario and McMaster Universities (WOMAC) score served as the primary outcome measure. Joint loading, the secondary outcome measure, was assessed using the external knee adduction moment. Peak external knee adduction moment, total WOMAC, and WOMAC pain scores were assessed at baseline and after 6 months. The total WOMAC and WOMAC pain scores for the intervention group were reduced from baseline to 6 months (p = 0.017 and p = 0.002, respectively), with no significant reductions for the control group. There was no difference between groups in magnitude of the reduction in total WOMAC (p = 0.50) or WOMAC pain scores (p = 0.31). The proportion of patients achieving a clinically important improvement in pain was greater in the intervention group than in the control group (p = 0.012). The variable‐stiffness shoes reduced the peak knee adduction moment (?6.6% vs. control, p < 0.001) in the 34 intervention subjects at 6 months. The adduction moment reduction significantly improved (p = 0.03) from the baseline reduction. The constant‐stiffness control shoe increased the peak knee adduction moment (+6.3% vs. personal, p = 0.004) in the 26 control subjects at 6 months. The results of this study showed that wearing the variable‐stiffness shoe lowered the adduction moment, reduced pain, and improved functionality after 6 months of wear. The lower adduction moment associated with wearing this shoe may slow the rate of progression of osteoarthritis after long‐term use. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:873–879, 2010     

关节镜辅助单髁置换术治疗膝内侧间室骨性关节炎的临床疗效观察

目的总结关节镜辅助单髁置换术治疗膝内侧间室骨性关节炎的临床疗效。方法选择自2008-03—2011-01行手术治疗的18例单侧膝关节骨性关节炎。均以膝关节内侧间室病损为主。术前进行MR及X线片评估;术中采用关节镜进行检查和清理。并行膝关节内侧间室单髁置换术：术后进行膝关节功能及影像学评估。结果所有患者均获平均21（18～36）个月随访,影像学检查显示假体位置良好,无松动与假体周围骨溶解的迹象。末次随访时膝关节功能HSS评分由术前71．3分提高至87．2分,优15膝,良3膝;平均关节活动范围（ROM）127°（112～141°）。结论关节镜下准确评估、清理关节病损为人工膝关节单髁置换术提供临床依据,提高了疗效,是治疗膝关节单间室骨性关节炎的有效方法。