Rana S. Hinman

Higher dynamic medial knee load predicts greater cartilage loss over 12 months in medial knee osteoarthritis

Objective Mechanical factors, in particular increased medial knee joint load, are believed to be important in the structural progression of knee osteoarthritis. This study evaluated the relationship of medial knee load during walking to indices of structural disease progression, measured on MRI, in people with medial knee osteoarthritis. Methods A longitudinal cohort design utilising a subset of participants (n=144, 72%) enrolled in a randomised controlled trial of lateral wedge insoles was employed. Medial knee load parameters including the peak knee adduction moment (KAM) and the KAM impulse were measured at baseline using three-dimensional gait analysis during walking. MRI at baseline and at 12 months was used to assess structural indices. Multiple regression with adjustment for covariates assessed the relationship between medial knee load parameters and the annual change in medial tibial cartilage volume. Binary logistic regression was used for the dichotomous variables of progression of medial tibiofemoral cartilage defects and bone marrow lesions (BML). Results A higher KAM impulse, but not peak KAM, at baseline was independently associated with greater loss of medial tibial cartilage volume over 12 months (β=29.9, 95% CI 6.3 to 53.5, p=0.01). No significant relationships were seen between medial knee load parameters and the progression of medial tibiofemoral cartilage defects or BML. Conclusion This study suggests knee loading, in particular the KAM impulse, may be a risk factor for loss of medial tibial cartilage volume. As knee load is modifiable, load-modifying treatments may potentially slow disease progression.

Aquatic Physical Therapy for Hip and Knee Osteoarthritis: Results of a Single-Blind Randomized Controlled Trial

Background and Purpose Aquatic physical therapy is frequently used in the management of patients with hip and knee osteoarthritis (OA), yet there is little research establishing its efficacy for this population. The purpose of this study was to evaluate the effects of aquatic physical therapy on hip or knee OA. Subjects A total of 71 volunteers with symptomatic hip OA or knee OA participated in this study. Methods The study was designed as a randomized controlled trial in which participants randomly received 6 weeks of aquatic physical therapy or no aquatic physical therapy. Outcome measures included pain, physical function, physical activity levels, quality of life, and muscle strength. Results The intervention resulted in less pain and joint stiffness and greater physical function, quality of life, and hip muscle strength. Totals of 72% and 75% of participants reported improvements in pain and function, respectively, compared with only 17% (each) of control participants. Benefits were maintained 6 weeks after the completion of physical therapy, with 84% of participants continuing independently. Discussion and Conclusion Compared with no intervention, a 6-week program of aquatic physical therapy resulted in significantly less pain and improved physical function, strength, and quality of life. It is unclear whether the benefits were attributable to intervention effects or a placebo response.

Hip strengthening reduces symptoms but not knee load in people with medial knee osteoarthritis and varus malalignment: a randomised controlled trial

OBJECTIVE To determine whether hip abductor and adductor muscle strengthening reduces medial compartment knee load and improves symptoms in people with medial tibiofemoral OA and varus malalignment. METHODS In a randomised controlled trial, 89 participants were randomly allocated to a hip strengthening group or to a control group with no intervention. The strengthening group performed a physiotherapist-supervised home exercise program targeting the hip abductor and adductor muscles for 12 weeks. The primary outcome was the peak external knee adduction moment measured using three-dimensional gait analysis by a blinded assessor. Secondary outcomes included a pain numeric rating scale, Western Ontario and McMaster Universities Osteoarthritis Index, step test, stair climb test, maximum isometric strength of hip and quadriceps muscles and participant-perceived rating of overall change. Intention-to-treat analyses were performed using linear regression modelling adjusting for baseline outcomes and other characteristics. RESULTS The trial was completed by 76/89 participants (85%). There was no significant between-group difference in change in the knee adduction moment [mean difference (95% confidence interval (CI)) 0.134 (-0.069 to 0.337) Nm/BW x HT%]. All pain, physical function and muscle strength measures showed significantly greater improvement in the strengthening group (all P<0.05). The relative risk (95% CI) of participant-perceived overall improvement in the strengthening group compared to the control group was 20.02 (6.21-64.47). CONCLUSIONS Although strengthening the hip muscles improved symptoms and function in this patient group, it did not affect medial knee load as measured by the knee adduction moment. Thus it is unlikely that hip muscle strengthening influences structural disease progression. TRIAL REGISTRATION ACTR12607000001493.

Lateral wedge insoles for medial knee osteoarthritis: 12 month randomised controlled trial

Objective To assess the effect of lateral wedge insoles compared with flat control insoles on improving symptoms and slowing structural disease progression in medial knee osteoarthritis. Design Randomised controlled trial. Setting Community in Melbourne, Australia. Participants 200 people aged 50 or more with clinical and radiographic diagnosis of mild to moderately severe medial knee osteoarthritis. Interventions Full length 5 degree lateral wedged insoles or flat control insoles worn inside the shoes daily for 12 months. Main outcome measures Primary symptomatic outcome was change in overall knee pain (past week) measured on an 11 point numerical rating scale. Primary structural outcome was change in volume of medial tibial cartilage from magnetic resonance imaging scans. Secondary clinical outcomes included changes in measures of pain, function, stiffness, and health related quality of life. Secondary structural outcomes included progression of medial cartilage defects and bone marrow lesions. Results Between group differences did not differ significantly for the primary outcomes of change in overall pain (−0.3 points, 95% confidence intervals −1.0 to 0.3) and change in medial tibial cartilage volume (−0.4 mm3, 95% confidence interval −15.4 to 14.6), and confidence intervals did not include minimal clinically important differences. None of the changes in secondary outcomes showed differences between groups. Conclusion Lateral wedge insoles worn for 12 months provided no symptomatic or structural benefits compared with flat control insoles. Trial registration Australian New Zealand Clinical Trials Registry ACTR12605000503628 and ClinicalTrials.gov NCT00415259.

Does knee malalignment mediate the effects of quadriceps strengthening on knee adduction moment, pain, and function in medial knee osteoarthritis? A randomized controlled trial

OBJECTIVE To examine whether the effects of 12 weeks of quadriceps strengthening on the knee adduction moment, pain, and function in people with medial knee osteoarthritis (OA) differ in those with and without varus malalignment. METHODS A single-blind, randomized controlled trial of 107 community volunteers with medial knee OA was conducted. Participants were stratified according to knee malalignment (more varus or more neutral) and then randomized into either a 12-week supervised home-based quadriceps strengthening group or a control group with no intervention. The primary outcome was the knee adduction moment, measured using 3-dimensional gait analysis. Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index scores (measuring pain and physical function), step test score, stair climb test score, and maximum quadriceps isometric strength. Analyses of covariance were carried out based on intent-to-treat principles. RESULTS Quadriceps strengthening did not significantly alter the knee adduction moment in either the more malaligned or the more neutral group (unadjusted knee adduction moment 0.12 and 0.05% Nm/BWxHT, respectively). Function did not improve significantly following quadriceps strengthening in either alignment group, but there was a significant improvement in knee pain in the more neutrally aligned group (P < 0.001). CONCLUSION Quadriceps strengthening did not have any significant effect on the knee adduction moment in participants with either more varus or more neutral alignment. The benefits of quadriceps strengthening on pain were more evident in those with more neutral alignment. Knee alignment thus represents a local mechanical factor that can mediate symptomatic outcome from exercise interventions in knee OA.

Ice-water immersion and delayed-onset muscle soreness: a randomised controlled trial

Objective: To determine if ice-water immersion after eccentric quadriceps exercise minimises the symptoms of delayed-onset muscle soreness (DOMS). Design: A prospective randomised double-blind controlled trial was undertaken. 40 untrained volunteers performed an eccentric loading protocol with their non-dominant leg. Interventions: Participants were randomised to three 1-min immersions in either ice water (5±1°C) or tepid water (24°C). Main outcome measures: Pain and tenderness (visual analogue scale), swelling (thigh circumference), function (one-legged hop for distance), maximal isometric strength and serum creatine kinase (CK) recorded at baseline, 24, 48 and 72 h after exercise. Changes in outcome measures over time were compared to determine the effect of group allocation using independent t tests or Mann–Whitney U tests. Results: No significant differences were observed between groups with regard to changes in most pain parameters, tenderness, isometric strength, swelling, hop-for-distance or serum CK over time. There was a significant difference in pain on sit-to-stand at 24 h, with the intervention group demonstrating a greater increase in pain than the control group (median change 8.0 vs 2.0 mm, respectively, p = 0.009). Conclusions: The protocol of ice-water immersion used in this study was ineffectual in minimising markers of DOMS in untrained individuals. This study challenges the wide use of this intervention as a recovery strategy by athletes.

Gait Modification Strategies for Altering Medial Knee Joint Load: A Systematic Review

To evaluate the effect of gait modification strategies on the external knee adduction moment (KAM), a marker of medial knee joint load; determine potentially adverse effects; assess the methodologic quality; and identify areas of future research.

Role of Muscle in the Genesis and Management of Knee Osteoarthritis

The muscles of the lower limb play an important role in the genesis and management of knee osteoarthritis (OA). This article outlines the influence of muscle activity on knee joint loading, the deficits in muscle function observed in people who have knee OA, and available evidence pertaining to the role of muscle in the development and progression of knee OA. It also discusses whether muscle deficits can be modified in knee OA and whether improvements in muscle function lead to improved symptoms and joint structure. It concludes with a discussion of exercise prescription for muscle rehabilitation in knee OA.

Patellar taping and bracing for the treatment of chronic knee pain: A systematic review and meta‐analysis

OBJECTIVE To evaluate the evidence for patellar taping and bracing in the management of chronic knee pain. METHODS Randomized or quasi-randomized studies assessing patellar taping or bracing effects on chronic knee pain were sourced from 7 electronic databases (to November 2006), and assessed using the Physiotherapy Evidence Database scale. Weighted mean differences were determined, and pooled estimates of taping and bracing effects were obtained using random-effects models. RESULTS Of 16 eligible trials, 13 investigated patellar taping or bracing effects in individuals with anterior knee pain, and 3 investigated taping effects in individuals with knee osteoarthritis (OA). The methodologic quality of the taping studies was significantly higher than the bracing studies (mean+/-SD 4.8+/-2.1 versus 2.8+/-0.8; P<0.05). On a 100-mm scale, tape applied to exert a medially-directed force on the patella decreased chronic knee pain compared with no tape by 16.1 mm (95% confidence interval [95% CI] -22.2, -10.0; P<0.001) and sham tape by 10.9 mm (95% CI -18.4, -3.4; P<0.001). For anterior knee pain and OA, medially-directed tape decreased pain compared with no tape by 14.7 mm (95% CI -22.8, -6.9; P<0.001) and 20.1 mm (95% CI -26.0, -14.3; P<0.001), respectively. There was disputable evidence from low-quality studies for patellar bracing benefits. CONCLUSION There was evidence that tape applied to exert a medially-directed force on the patella produces a clinically meaningful change in chronic knee pain. There was limited evidence to demonstrate the efficacy of patellar bracing. These outcomes were limited by the presence of high heterogeneity between study outcomes and significant publication bias.

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.