Thomas P Andriacchi

Thomas P Andriacchi
Stanford University | SU · Department of Mechanical Engineering

PhD

About

492
Publications
65,348
Reads
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28,066
Citations
Citations since 2016
58 Research Items
9941 Citations
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201620172018201920202021202205001,0001,500
201620172018201920202021202205001,0001,500
201620172018201920202021202205001,0001,500
Additional affiliations
September 2006 - present
VA Palo Alto Health Care System
Position
  • Reseach Career Scientist
January 1998 - present
Stanford University
June 1974 - June 1998
Rush University Medical Center

Publications

Publications (492)
Conference Paper
ILIOTIBIAL BAND SYNDROME INJURED RUNNERS INCREASE FLEXIBILITY USING SOFT TISSUE MOBILIZATION AND INCREASE FUNCTIONAL STRENGTH USING A HEAT PACK-IMPLICATIONS FOR FASTER RECOVERY
Article
Mechanical factors have been implicated in the development of osteoarthritis after anterior cruciate ligament (ACL) reconstruction. This study tested for associations between ambulatory joint loading (total joint moment, TJM, and vertical ground reaction force, vGRF) and changes in serum levels of cartilage oligomeric matrix protein (COMP) in respo...
Article
Osteoarthritis (OA) is a leading cause of pain and disability for which disease modifying treatments remain lacking. This is likely because the symptoms and radiographic changes of OA occur after the onset of irreversible changes. Defining and treating earlier disease states are therefore needed to delay or halt OA progression. Taking this concept...
Article
Full-text available
Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with...
Article
Background Reduced quadriceps function and proprioception can cause decreased mobility during stair navigation in patients with knee pain. Patients can benefit from interventions to mitigate pain and restore quadriceps function. Activating the somatosensory system via intermittent vibrational stimulation has the potential to improve stair navigatio...
Article
Disruptions in knee biomechanics during walking following anterior cruciate ligament (ACL) injury have been suggested to lead to the development of premature knee osteoarthritis (OA) and to be potential markers of OA risk and targets for intervention. This study investigated if side‐to‐side differences in early stance peak vertical ground reaction...
Article
Objective To address the need for early knee osteoarthritis (OA) markers by testing if longitudinal cartilage thickness changes are associated with specific biomechanical and biological measures acquired at a baseline test in asymptomatic aging subjects. Design Thirty-eight asymptomatic subjects over age 45 years were studied at baseline and at an...
Article
Background Patellofemoral joint degeneration and dysfunction after anterior cruciate ligament reconstruction (ACLR) are increasingly recognized as contributors to poor clinical outcomes. Purpose To determine if greater deep cartilage matrix disruption at 2 years after ACLR, as assessed by elevated patellofemoral magnetic resonance imaging (MRI) ul...
Article
Full-text available
Alterations in cartilage thickness (CTh) are a hallmark of knee osteoarthritis, which remain difficult to characterize at high resolution, even with modern magnetic resonance imaging (MRI), due to a paucity of standardization tools. This study aimed to assess a computational anatomy method producing standardized two-dimensional femorotibial CTh map...
Article
This study aimed to determine if changes in knee adduction moment (KAM) after 6 months of variable‐stiffness shoe wear are associated with changes in symptoms or serum levels of cartilage oligomeric matrix protein (COMP) following a mechanical stimulus in subjects with medial knee osteoarthritis. Twenty‐five subjects were enrolled in the study and...
Article
Full-text available
Objective This study aimed to improve our understanding of the relationship between bone and cartilage by characterizing the morphological coupling between these mechanosensitive tissues exposed to the same mechanical environment within each knee. Specifically, it reanalyzed a prior dataset to test the hypothesis that the locations of thickest cart...
Article
Background Pain and proprioception deficits are often associated with knee pathologies and resultant quadriceps muscle inhibition. There is a need for new approaches to mitigate active knee pain and restore muscle function during walking. Activating properties of the somatosensory system with common pain and sensory pathways offers a novel opportun...
Article
Full-text available
Objective To stimulate future research directions that seek solutions for osteoarthritis (OA) at the interface between diverse disciplines and address osteoarthritis (OA) as a serious disease with a complexity that has presented a barrier to finding safe effective solutions. Methods Sessions were conducted at the 2019 meetings of the Orthopaedic R...
Article
The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and qu...
Article
This study investigated associations between changes in the total joint moment (TJM) at the knee and changes in cartilage thickness after anterior cruciate ligament reconstruction (ACLR). Seventeen subjects (5 males; age: 29.6±7.3 yrs) with unilateral ACLR underwent gait analysis and MRI at baseline (2.2±0.3 yrs post‐ACLR) and at long‐term follow‐u...
Article
Background: Anterior cruciate ligament (ACL) injury is often followed by quadriceps deficits that are apparent with gait analysis. The deficit frequently remains after ACL reconstruction (ACLR). As such, evaluation of ACLR patients could be enhanced by a simple method to detect quadriceps deficits. Analyzing forward trunk flexion during stair asce...
Article
Quadriceps muscle rehabilitation following knee injury or disease is often hampered by pain, proprioception deficits or instability associated with inhibition of quadriceps activation during walking. The cross-modal plasticity of the somatosensory system with common sensory pathways including pain, pressure and vibration offers a novel opportunity...
Chapter
This chapter discusses the early development of knee osteoarthritis with regard to ACL injury. In addition, the kinematic and kinetic changes in the knee after ACL injury are summarized. The interaction between altered joint kinematics and the structural and biological components of articular cartilage is explored as an initiating mechanism of prem...
Chapter
This chapter discusses the role of shoe-surface interaction with regard to the risk of noncontact ACL injuries in female athletes. Shoe characteristics such as the number, diameter, length, and placement of cleats are described relative to the role they may play in ACL injuries. The effect of playing surface characteristics is described for differe...
Article
Full-text available
Objective: To introduce an integrated joint system (IJS) model of joint health and osteoarthritis (OA) pathophysiology through a systematic review of the cross-sectional relationships among three knee properties (cartilage thickness, gait mechanics, and subchondral bone mineral density). Methods: Searches using keywords associated with the three...
Article
Objective: Quantitative MRI Ultrashort echo time (UTE) T2* is sensitive to cartilage deep tissue matrix changes after anterior cruciate ligament reconstruction (ACLR). This study was performed to determine whether UTE-T2* profile analyses is a useful clinical metric for assessing cartilage matrix degeneration. This work tests the hypotheses that U...
Article
Full-text available
Background: Anterior cruciate ligament (ACL) injury increases risk for posttraumatic knee osteoarthritis (OA). Quantitative ultrashort echo time enhanced T2* (UTE-T2*) mapping shows promise for early detection of potentially reversible subsurface cartilage abnormalities after ACL reconstruction (ACLR) but needs further validation against establish...
Article
The objective of the study was to test the hypothesis that serum levels of cartilage oligomeric matrix protein (COMP) would decrease and serum levels of tumor-necrosis factor alpha (TNF-α) and selected matrix metalloproteinases (MMPs) would increase in response to bed rest (BR) and that these changes are unaffected by the intake of potassium bicarb...
Article
The purpose of this study was to longitudinally investigate changes in knee joint kinematics and kinetics from 2 to 8 years post-ACLR. Seventeen subjects with primary unilateral transtibial ACLR performed bilateral gait analysis approximately 2 years and 8 years post-ACLR. Seventeen matched healthy control subjects were also analyzed. Kinematic and...
Article
Objective: To test long-term effectiveness of neuromuscular exercise (NEMEX) with instructions in optimized pharmacological treatment (PHARMA) on activities of daily living (ADL) in patients with early knee osteoarthritis. Design: 12-months follow-up from a randomized controlled trial. Participants with mild-to-moderate medial tibiofemoral knee...
Article
Using serum biomarkers to assess osteoarthritis (OA) disease state and risks of progression remain challenging. This study tested the hypothesis that changes to serum biomarkers in response to a mechanical stimulus in patients with medial knee OA signal cartilage thickness changes five years later. Specifically, serum concentrations of a collagen d...
Article
The increased use of gait analysis has raised the need for a better understanding of how walking speed and demographic variations influence asymptomatic gait. Previous analyses mainly reported relationships between subsets of gait features and demographic measures, rendering it difficult to assess whether gait features are affected by walking speed...
Article
Full-text available
While cartilage thickness alterations are a central element of knee osteoarthritis (OA), differences among disease stages are still incompletely understood. This study aimed to quantify the spatial-variations in cartilage thickness using anatomically-standardized thickness maps and test if there are characteristic patterns in patients with differen...
Article
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....
Article
Objective: To test if sagittal plane gait mechanics parameters and serum inflammation levels differ between healthy asymptomatic subjects and asymptomatic subjects with magnetic resonance imaging (MRI) evidence of cartilage loss. Design: Gait mechanics and resting serum tumor necrosis factor-α (TNFα) concentrations were measured for two groups o...
Article
Full-text available
Background Changes in knee kinematics have been identified in the early stages of osteoarthritis (OA). However, there is a paucity of information on the nature of kinematic change that occur with aging prior to the development of OA, This study applied a robust statistical method (Principal Component Analysis) to test the hypothesis that coupling b...
Data
Individual PC scores for all participants and all PC (n = 74) are included in a supplementary data file. Each row contains data for a participants and each column is a PC score. (XLSX)
Article
Background: Altered knee kinematics after anterior cruciate ligament injury and reconstruction (ACLR) have been implicated in the development of posttraumatic osteoarthritis (PTOA), leading to poor long-term clinical outcomes. Purpose: This study was conducted to determine (1) whether the average knee center of rotation (KCOR), a multidimensiona...
Article
Objective: To investigate the effect of a NEuro-Muscular EXercise (NEMEX) therapy program compared with instructions in optimized analgesics and anti-inflammatory drug use (PHARMA), on measures of knee-joint load in people with mild to moderate knee osteoarthritis. We hypothesized that knee joint loading during walking would be reduced by NEMEX an...
Article
Background: Altered knee kinematics after anterior cruciate ligament injury and reconstruction (ACLR) have been implicated in the development of premature osteoarthritis (OA), leading to poor long term clinical outcomes.
Article
This study tested the hypothesis that side-to-side differences in knee gait mechanics 2 years after anterior cruciate ligament (ACL) reconstruction are associated with long-term (∼8 years post-reconstruction) changes in patient-reported outcome scores. Sixteen subjects (5 males; age: 29.1 ± 7.1 yrs) with primary unilateral ACL reconstruction were g...
Article
Although kinematic alterations during walking have been reported with knee osteoarthritis (OA), there is a paucity of longitudinal data, therefore limiting our understanding of the role of kinematics in OA development. This study tested the hypothesis that less knee extension angle and less posterior displacement of the femur relative to the tibia...
Conference Paper
Purpose: Knee osteoarthritis (OA) is a mechanically driven disease. It is suggested that medial tibiofemoral knee-joint load increases with pharmacologic pain relief, indicating that pharmacologic pain relief may be positively associated with disease progression. Treatment modalities that can both relieve pain and reduce knee-joint load would be pr...
Article
Background: The incidence of anterior cruciate ligament (ACL) injuries may be decreased through the use of intervention programs that focus on increasing the knee flexion angle during jump landing, which decreases strain on the ACL. Purpose: To investigate whether intervention training designed to change the knee flexion angle during landing cau...
Article
Reducing the knee adduction moment (KAM) is a promising treatment for medial compartment knee osteoarthritis (OA). Although several gait modifications to lower the KAM have been identified, the potential to combine modifications and individual dose-responses remain unknown. This study hypothesized that: (i) there is a general scheme consisting of m...
Article
There is increasing evidence that the regional spatial variations in the biological and mechanical properties of articular cartilage are an important consideration in the pathogenesis of knee osteoarthritis (OA) following kinematic changes at the knee due joint destabilizing events (such as an anterior cruciate ligament injury). Thus, given the sen...
Article
Background: Alterations in knee kinematics after partial meniscectomy have been linked to the increased risk of osteoarthritis in this population. Understanding differences in kinematics during static versus dynamic activities of increased demand can provide important information regarding the possible underlying mechanisms of these alterations....
Article
To test if the relationship between knee kinetics during walking and regional patterns of cartilage thickness is influenced by disease severity we tested the following hypotheses in a cross-sectional study of medial compartment osteoarthritis (OA) subjects: (1) the peak knee flexion (KFM) and adduction moments (KAM) during walking are associated wi...
Article
Meniscal damage and meniscectomy lead to subsequent osteoarthritis (OA) of the knee joint through multiple and diverse mechanisms, yet the interaction of these mechanisms remains unknown. Therefore, the aim of this review is to suggest the multi-scale, multi-faceted components involved between meniscal injury or meniscectomy and the initiation of O...
Article
There is increasing evidence that kinematic changes after anterior cruciate ligament (ACL) injury can influence the risk for premature osteoarthritis. However, kinematics can change over time, and the factors influencing those changes remain unknown but potentially important. The purpose of this study was to perform gait analysis on a population of...
Article
Osteoarthritis is a leading cause of human suffering and disability for which disease modifying treatments are lacking. OA occurs through complex and dynamic interplays between diverse factors over long periods of time. The traditional research and clinical focus on OA, the end stage disease,obscured understandingpathogenesis prior to reaching a co...
Article
Knee osteoarthritis (OA), a leading cause of disability, is more prevalent in women than men. Wearing high heeled shoes has been implicated as a potential contributing factor for the higher lifetime risk of osteoarthritis in women. This study tests the hypotheses that changes to knee kinematics and kinetics observed during high heeled walking incre...
Article
Full-text available
Background Knee osteoarthritis (OA) is a mechanically driven disease, and it is suggested that medial tibiofemoral knee-joint load increases with pharmacologic pain relief, indicating that pharmacologic pain relief may be positively associated with disease progression. Treatment modalities that can both relieve pain and reduce knee-joint load would...
Article
Knee osteoarthritis is a disease that can be initiated along multiple pathways that ultimately leads to pain, loss of function and breakdown of the articular cartilage. While the various pathways have biological and structural elements, the mechanical pathways play a critical role in the development of the disease. The forces and motions occurring...
Article
Early detection of osteoarthritis (OA) remains a critical yet unsolved multifaceted problem. To address the multifaceted nature of OA a systems model was developed to consolidate a number of observations on the biological, mechanical and structural components of OA and identify features common to the primary risk factors for OA (aging, obesity and...
Article
Objective To test the hypothesis that knee cartilage changes over five years are associated with baseline peak knee adduction (KAM) and peak knee flexion moment (KFM) during early stance. Design Baseline KAM and KFM were measured in sixteen subjects with medial knee OA. Regional changes in cartilage thickness and changes in medial-to-lateral thick...
Article
Background: Mechanical load and elevated levels of proinflammatory cytokines have been associated with the risk for osteoarthritis (OA), yet, the potential amplification of the risk for OA based on the interaction of these mechanical and biological factors is not well understood. Objective: To evaluate the regional response of chondrocytes to the c...