The mechanism of the effect of obesity in knee osteoarthritis: The mediating role of malalignment

Abstract

BMI was related to OA severity in those with varus knees but not in those with valgus knees. Much of the effect of BMI on the severity of medial tibiofemoral OA was explained by varus malalignment, after controlling for sex. Whether it precedes or follows the onset of disease, varus malalignment is one local factor that may contribute to rendering the knee most vulnerable to the effects of obesity.

Lower Extremity Pain Is Associated With Reduced Function and Psychosocial Health in Obese Children

“…This finding indicates that factors beyond BMI may be associated with reports of LE pain in obese children. Lower extremity malalignment is frequently present in obese children [28][29][30]52] and is associated with pain in other populations [45,47,48,64]. Further investigation into factors such as LE alignment that may differ between obese children with pain and those without pain is warranted.…”

“…Obesity-related musculoskeletal comorbidities, including joint pain and lower extremity malalignment, are well characterized among adults [16,17,47]. In adults, increasing body mass index (BMI) and obesity result in knee pain [19], progressive physical disability [5,18], diminished health-related quality of life [18], and a clear risk of development of knee osteoarthritis [7,24,47].…”

Overview of the relationship between pain and obesity: What do we know? Where do we go next?

“…Other hypothesized mechanical-structural hypotheses include increased loading [55], joint misalignment [56][57], structural changes [58], and decreased ambulation and conditioning [37][38] that result from overweight/obesity.…”

Effect of Local Alignment on Compartmental Patterns of Knee Osteoarthritis

“…Similarly, we found that worsening local valgus alignment is associated with a significantly increased risk of having predominantly lateral disease. Although previous studies have documented significant relationships between alignment and compartment disease [1][2][3][4] , the authors based their determination of alignment on fulllength lower-extremity radiographs. Such radiographs expose the patient to higher amounts of radiation, require greater technical expertise on the part of the radiology technician, and are more expensive than short knee radiographs 5 .…”

“…In the published studies in which full-length radiographs were used, the knees were frequently categorized, on the basis of absolute values, as normal, with pathological varus, or with pathological valgus [1][2][3][4] . This was done readily because there were already well-established definitions of alignment as measured on full-length radiographs.…”