Varus Thrust and Incident and Progressive Knee Osteoarthritis

Abstract

Background To determine if varus thrust, bowing-out of the knee during gait, i.e., the first appearance or worsening of varus alignment during stance, is associated with incident and progressive knee osteoarthritis (OA), we undertook an Osteoarthritis Initiative ancillary study. We further considered hypothesized associations adjusted for static alignment, anticipating some attenuation. Methods 2–3 trained examiners/site at 4 sites observed gait. In eligible knees, incident OA was analyzed as subsequent incident KL≥2, whole and partial-grade medial joint space narrowing (JSN), and annualized loss of joint space width (JSW), and progression as medial JSN and JSW loss. Outcomes were assessed over up to 7 years of follow-up. Analyses were knee-level, using multivariable logistic and linear regression with GEE to account for between-limb correlation. Results The incident OA sample included 4187 knees/2610 persons; the progression sample included 3421 knees/2284 persons. In knees with OA, thrust was associated with progression by each outcome adjusting for age, gender, BMI, and pain. In knees without OA, varus thrust was not associated with incident OA or other outcomes. After adjustment for alignment, the thrust/progression association was attenuated but an independent association persisted for partial grade JSN and JSW loss outcome models. WOMAC Pain and alignment were consistently associated with all outcomes. Within the stratum of varus knees, thrust was associated with an increased risk of progression. Conclusions Varus thrust visualized during gait is associated with knee OA progression and should be a target of intervention development.

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

“…The use of 1 observer minimized the introduction of variability from multiple observers. A clear consensus on the best practice for operationally defining thrust has yet to be reached, as definitions of thrust and methods for assessing thrust vary across the literature . The studies cited here categorize thrust as a binary variable (present or absent), although some authors (e.g., 9,11,12,24) graded thrust on an ordinal scale before ultimately dichotomizing the thrust variable.…”

“…The relation of varus thrust to structural damage at the knee has been well‐documented. Varus thrust has been previously linked to increased odds of medial radiographic OA disease progression , increased odds of worsening medial tibiofemoral cartilage damage and incident and worsening bone marrow lesions , and prevalent patellofemoral OA . Importantly, knee thrust can be identified visually in a clinical setting, and evidence suggests that thrust may be modified using inexpensive and noninvasive therapies .…”

Relationship Between Varus Thrust During Gait and Low Back Pain in Individuals With Knee Osteoarthritis

“…Varus thrust during gait is an easily assessed measure of frontal plane dynamic knee motion that is defined as the dynamic worsening or abrupt onset of varus motion during weight acceptance . Varus thrust has been previously linked to the progression of knee OA , worsening cartilage and bone marrow lesions , worsening and incidence of knee pain , and severe knee pain . Although thrust influences the entire kinematic chain of the lower extremity and may cause altered lower back motions, its effects on LBP have yet to be elucidated.…”

The mechanism of TDP‐43 gene expression on inflammatory factors and the JNK and p38 MAPK signalling pathways in ischaemic hypoxic stress dependence

“…When OA becomes diseased, articular cartilage is the first damaged site, in which chondrocytes are the only cells in the osteoarticular cartilage that synthesise cartilage matrix . Chondrocytes mediate the internal regulation system of articular cartilage and synthesise various growth factors and cytokines, which regulate the pathophysiological processes, such as the formation of cartilage tissue and wound repair with stabilisers . In the occurrence of OA, various harmful factors directly or indirectly affect chondrocytes, leading to the degradation of chondrocyte matrix more than synthesis, ultimately resulting in damage of the chondrocyte matrix .…”

“…2 Chondrocytes mediate the internal regulation system of articular cartilage and synthesise various growth factors and cytokines, which regulate the pathophysiological processes, such as the formation of cartilage tissue and wound repair with stabilisers. 3 In the occurrence of OA, various harmful factors directly or indirectly affect chondrocytes, leading to the degradation of chondrocyte matrix more than synthesis, ultimately resulting in damage of the chondrocyte matrix. 4 Therefore, how to effectively overcome the damage to the internal control system of the articular cartilage is the focus and difficulty of current investigations.…”