Do individuals with knee osteoarthritis walk with distinct knee biomechanics and muscle activation characteristics? An investigation of knee osteoarthritis, hip osteoarthritis, and asymptomatic groups.

Background: Biomechanical markers including reductions in sagittal plane kinematics and moments, increases in knee adduction moments (KAM), and altered muscle activations have been identified as hallmark indicators of knee osteoarthritis (OA). However, it remains unknown whether these features of knee OA gait are exclusive to the diseased joint.

Research Question: To determine whether specific gait outcomes previously linked to symptomatic medial compartment knee OA are unique to knee OA by concurrently investigating a group of asymptomatic individuals and those with hip OA.

The effect of a frontal plane gait perturbation bout on knee biomechanics and muscle activation in older adults and individuals with knee osteoarthritis.

Background: Walking can be a challenging task for individuals with knee osteoarthritis and many older adults. The purpose was to determine the immediate effect of a frontal plane perturbation bout during walking on knee biomechanics and muscle activation patterns in these groups.

Methods: 44 asymptomatic older adults and 32 individuals with knee osteoarthritis were recruited.

Association Between Knee Joint Muscle Activation and Knee Joint Moment Patterns During Walking in Moderate Medial Compartment Knee Osteoarthritis: Implications for Secondary Prevention.

Objective: To determine associations between knee moment features linked to osteoarthritis (OA) progression, gait muscle activation patterns, and strength.

Design: Cross-sectional secondary analysis.

Setting: Gait laboratory.

Differences in Baseline Joint Moments and Muscle Activation Patterns Associated With Knee Osteoarthritis Progression When Defined Using a Clinical Versus a Structural Outcome.

Both structural and clinical changes can signify knee osteoarthritis progression; however, these changes are not always concurrent. A better understanding of mechanical factors associated with progression and whether they differ for structural versus clinical outcomes could lead to improved conservative management. This study examined baseline gait differences between progression and no progression groups defined at an average of 7-year follow-up using 2 different outcomes indicative of knee osteoarthritis progression: radiographic medial joint space narrowing and total knee arthroplasty.

Baseline Gait Muscle Activation Patterns Differ for Osteoarthritis Patients Who Undergo Total Knee Arthroplasty Five to Eight Years Later From Those Who Do Not.

Objective: To determine if baseline quadriceps and hamstrings muscle activity patterns differed between those with medial-compartment knee osteoarthritis (OA) who advanced to total knee arthroplasty (TKA) and those who did not advance to TKA, and to examine associations between features extracted from principal component analysis (PCA) and discrete measures.

Methods: Surface electromyograms of the vastus lateralis and medialis, rectus femoris, and lateral and medial hamstrings during walking were collected from 54 individuals with knee OA. Amplitude and temporal characteristics from PCA, co-contraction indices (CCI) for lateral and medial muscle pairs, and root mean square (RMS) amplitudes for early, mid, late, and overall stance were calculated from electromyographic waveforms.

Walking challenges in moderate knee osteoarthritis: A biomechanical and neuromuscular response to medial walkway surface translations.

Sensations of knee instability are self-reported in 60-80% of individuals with knee osteoarthritis. These sensations are most often reported during walking; however, it remains unclear how they affect knee joint biomechanics and muscle activation patterns as indicators of joint function. Perturbation paradigms may provide insight into how the knee joint responds to walking challenges.

Longitudinal evidence links joint level mechanics and muscle activation patterns to 3-year medial joint space narrowing.

Background: It is currently not known if there are different mechanical factors involved in accelerated rates of knee osteoarthritis structural progression. Data regarding the role of the transverse plane moment along with the contributions to joint loading from muscle activity, a primary contributor to the joint loading environment, is not well represented in the current literature on knee OA radiographic progression. The objective of this study was to understand if a 3-year end point corroborates what has been shown for longer term radiographic progression or provides more insight into factors that may be implicated in more accelerated radiographic progression than those shown previously.

Co-activation is not altered in the contra-lateral limb of individuals with moderate knee osteoarthritis compared to healthy controls.

Background: Contra-lateral knee joint function in individuals with moderate knee osteoarthritis is not well understood, despite the functional burden of bilateral osteoarthritis on end stage clinical management. The purpose of this study was to determine whether co-activation and joint biomechanics are altered in the contra-lateral limb compared to age-matched controls.

Methods: 20 Individuals with moderate knee osteoarthritis and 20 asymptomatic individuals walked on an instrumented dual belt treadmill at a self-selected speed.

The prognostic value of pain catastrophizing in health-related quality of life judgments after Total knee arthroplasty.

Background: Total knee arthroplasty (TKA) is a highly effective procedure that yields reductions in pain and disability associated with end stage osteoarthritis (OA) of the knee. Quality of life instruments are frequently used to gauge the outcomes of total knee arthroplasty (TKA). However, research suggests that post-TKA reductions in symptom severity may not be the sole predictors of quality of life post-TKA.

Reductions in Perceived Injustice are Associated With Reductions in Disability and Depressive Symptoms After Total Knee Arthroplasty.

Introduction: Perceptions of injustice have been associated with problematic recovery outcomes in individuals with a wide range of debilitating pain conditions. It has been suggested that, in patients with chronic pain, perceptions of injustice might arise in response to experiences characterized by illness-related pain severity, depressive symptoms, and disability. If symptoms severity and disability are important contributors to perceived injustice (PI), it follows that interventions that yield reductions in symptom severity and disability should also contribute to reductions in perceptions of injustice.

Dual-belt treadmill familiarization: Implications for knee function in moderate knee osteoarthritis compared to asymptomatic controls.

Background: Effect of treadmill familiarization on knee function in osteoarthritis is not clear. Purpose was to determine whether spatiotemporal characteristics, knee joint biomechanics and muscle activation patterns change as individuals with and without medial compartment knee osteoarthritis familiarize to dual-belt treadmill walking over 6min.

Methods: 20 individuals with knee osteoarthritis and 20 asymptomatic controls walked at a self-selected speed.

The effect of age and knee osteoarthritis on muscle activation patterns and knee joint biomechanics during dual belt treadmill gait.

Purpose: To compare a group of individuals with moderate medial compartment knee osteoarthritis (OA) to both an age-matched asymptomatic group of older adults and younger adults to determine whether differences in knee joint muscle activation patterns and joint biomechanics exist during gait between these three groups.

Scope: 20 young adults, 20 older adults, and 40 individuals with moderate knee OA were recruited. Using standardized procedures, surface electromyograms were recorded from the vastus lateralis and medialis, rectus femoris and the medial and lateral hamstrings.

Asymptomatic and symptomatic individuals with the same radiographic evidence of knee osteoarthritis walk with different knee moments and muscle activity.

There is an established discordance between the structural joint damage and clinical symptoms of knee osteoarthritis; however, there has been little investigation into the differences in joint level biomechanics and muscle activation patterns during gait between symptomatic and asymptomatic individuals with the same radiographic evidence of osteoarthritis. The objective of this study was to examine three-dimensional knee joint biomechanics and muscle activation differences during gait between asymptomatic and symptomatic individuals with radiographic knee osteoarthritis. A total of 54 asymptomatic and 59 symptomatic individuals with a Kellgren-Lawrence osteoarthritis radiographic grade of 2 underwent a comprehensive gait analysis to examine differences in the magnitude and patterns of the knee flexion angle, three-dimensional net resultant moments, and electromyography of the quadriceps, hamstrings, and gastrocnemii during over ground walking between the two groups.

Osteochondral Biopsy Analysis Demonstrates That BST-CarGel Treatment Improves Structural and Cellular Characteristics of Cartilage Repair Tissue Compared With Microfracture.

Objective: The efficacy and safety of BST-CarGel, a chitosan-based medical device for cartilage repair, was compared with microfracture alone at 1 year during a multicenter randomized controlled trial (RCT) in the knee. The quality of repair tissue of osteochondral biopsies collected from a subset of patients was compared using blinded histological assessments.

Methods: The international RCT evaluated repair tissue quantity and quality by 3-dimensional quantitative magnetic resonance imaging as co-primary endpoints at 12 months.

Obesity is associated with higher absolute tibiofemoral contact and muscle forces during gait with and without knee osteoarthritis.

Background: Obesity is an important risk factor for knee osteoarthritis initiation and progression. However, it is unclear how obesity may directly affect the mechanical loading environment of the knee joint, initiating or progressing joint degeneration. The objective of this study was to investigate the interacting role of obesity and moderate knee osteoarthritis presence on tibiofemoral contact forces and muscle forces within the knee joint during walking gait.

Relationship between knee adduction moment patterns extracted using principal component analysis and discrete measures with different amplitude normalizations: Implications for knee osteoarthritis progression studies.

Background: Knee adduction moment discrete features (peaks and impulses) are commonly reported in knee osteoarthritis gait studies, but they do not necessarily capture loading patterns. Principal component analysis extracts dynamic patterns, but can be difficult to interpret. This methodological study determined relationships between external knee adduction moment discrete measures and principal component analysis features, and examined whether amplitude-normalization methods influenced differences in those with knee osteoarthritis who progressed to surgery versus those that did not.

Chondroinduction Is the Main Cartilage Repair Response to Microfracture and Microfracture With BST-CarGel: Results as Shown by ICRS-II Histological Scoring and a Novel Zonal Collagen Type Scoring Method of Human Clinical Biopsy Specimens.

Background: Current cartilage repair histological scoring systems are unable to explain the relationship between collagen type II deposition and overall repair quality.

Purpose/hypothesis: The purpose of this study was to develop a novel zonal collagen type (ZCT) 5-point scoring system to measure chondroinduction in human clinical biopsy specimens collected after marrow stimulation. The hypothesis was that the ZCT scores would correlate with the International Cartilage Repair Society-II (ICRS-II) overall histological repair assessment score and glycosaminoglycan (GAG) content.

BST-CarGel® Treatment Maintains Cartilage Repair Superiority over Microfracture at 5 Years in a Multicenter Randomized Controlled Trial.

Objective: The efficacy and safety of BST-CarGel®, a chitosan scaffold for cartilage repair was compared with microfracture alone at 1 year during a multicenter randomized controlled trial in the knee. This report was undertaken to investigate 5-year structural and clinical outcomes.

Design: The international randomized controlled trial enrolled 80 patients, aged 18 to 55 years, with grade III or IV focal lesions on the femoral condyles.

Three-dimensional biomechanical gait characteristics at baseline are associated with progression to total knee arthroplasty.

Objective: To determine if baseline 3-dimensional (3-D) biomechanical gait patterns differed between those patients with moderate knee osteoarthritis (OA) who progressed to total knee arthroplasty (TKA) and those that did not, and whether these differences had predictive value.

Methods: Fifty-four patients with knee OA had ground reaction forces and segment motions collected during gait. 3-D hip, knee, and ankle angles and moments were calculated over the gait cycle.

The role of perceived injustice in the prediction of pain and function after total knee arthroplasty.

Emerging evidence suggests that the appraisal of pain and disability in terms of justice-related themes contributes to adverse pain outcomes. To date, however, research on the relation between perceived injustice and pain outcomes has focused primarily on individuals with musculoskeletal injuries. The primary aim of this study was to investigate the role of perceived injustice in the prediction of pain and disability after total knee arthroplasty (TKA).

Hip abductor function in individuals with medial knee osteoarthritis: Implications for medial compartment loading during gait.

Background: Hip abductor muscles generate moments of force that control lower extremity frontal plane motion. Strengthening these muscles has been a recent trend in therapeutic intervention studies for knee osteoarthritis. The current study investigated the relationship between hip abductor muscle function (strength and activation) and the net external knee adduction moment during gait in those with medial compartment knee osteoarthritis.

Economic evaluation of BST-CarGel as an adjunct to microfracture vs microfracture alone in knee cartilage surgery.

Objectives: Knee cartilage damage is a common cause of referral for orthopedic surgery. Treatment aims to reduce pain and symptoms by repairing cartilage. Microfracture, the current standard of care, yields good short-term clinical outcomes; however, treatment might fail after 2-3 years.

Novel scaffold-based BST-CarGel treatment results in superior cartilage repair compared with microfracture in a randomized controlled trial.

Background: Microfracture, the standard of care, is recognized to be an incomplete solution for cartilage damage. BST-CarGel, a chitosan-based medical device, is mixed with autologous whole blood and is applied to a microfractured cartilage lesion in which it physically stabilizes the clot and guides and enhances marrow-derived repair. An international, multicenter, randomized controlled trial was conducted to evaluate BST-CarGel treatment compared with microfracture alone in the repair of cartilage lesions in the knee.

Changes in knee joint muscle activation patterns during walking associated with increased structural severity in knee osteoarthritis.

Purpose: To determine whether alterations in knee joint muscle activation patterns during gait were related to structural severity determined by Kellgren-Lawrence (KL) radiographic grades, for those with a moderate knee OA classification.

Scope: Eighty-two individuals with knee OA, classified as moderate using a functional and clinical criterion were stratified on KL-grade (KL II, KL III and KL IV). Thirty-five asymptomatic individuals were matched for age and walking velocity.