Meta-analysis on the association between knee extensor strength and structural changes of knee osteoarthritis

Abstract

This study aimed to perform a meta-analysis to evaluate whether knee extensor (KE) strength weakness was associated with increased structural worsening in knee osteoarthritis (KOA) including joint space narrowing (JSN) and cartilage loss. PubMed, Embase, Scopus, ScienceDirect, Web of Science, and Cochrane library were searched from their inception to May 2020, to identify eligible studies. Odds ratios (ORs) accompanied by 95% confidence intervals (CIs) were calculated for the relationship between KE strength and outcomes. Totally eleven longitudinal studies were included. The pooled crude OR indicated no significant association between KE strength weakness and KOA progression of JSN (OR: 1.13, 95% CI: 0.90, 1.42), and this result duplicated after confounders were adjusted (OR: 1.10, 95% CI: 0.87, 1.39). Subgroup analysis showed the association remained non-significant in sex-specific outcomes and subsets of neutral and malaligned knees, but there was a trend toward increased risk of JSN progression in female knees with low strength (OR: 1.24, 95% CI: 0.87, 1.76, I 2 = 82%). The pooled crude OR showed that KE strength weakness was associated with increased risk of cartilage loss (OR:1.43, 95% CI: 1.05, 1.95). After adjustment, we found a non-significant trend that low KE strength could increase the risk of cartilage loss (OR: 1.25, 95% CI: 0.95, 1.64), and this trend was separately observed in tibiofemoral or patellofemoral compartments. This meta-analysis suggested that KE strength weakness was not significantly associated with an increased risk of radiographic structural KOA progression in patients with KOA or known risk factors for KOA. However, there was a trend that women with weaker KE strength displayed a higher risk of JSN worsening and that KE strength weakness had an association with an increased risk of cartilage damage.

Quadriceps strength is negatively associated with knee joint structural abnormalities—data from osteoarthritis initiative

“…Hou et al . [ 25 ] conducted a meta-analysis concerning the association with cartilage damage, suggesting there existed a trend that lower quadriceps strength could increase the risk of cartilage damage in both TFJ and PFJ. However, this meta-analysis did not take the effect of gender into consideration.…”

“…Quadriceps is the main absorber of harmful loading and its secretion, myokines (e.g., insulin-like growth factor 1 and Irisin), may have chondroprotective effects [10,11]. Hou et al [25] conducted a meta-analysis concerning the association with cartilage damage, suggesting there existed a trend that lower quadriceps strength could increase the risk of cartilage damage in both TFJ and PFJ. However, this meta-analysis did not take the effect of gender into consideration.…”

Anterior Knee Pain: State of the Art

“…AKP has a characteristically multifactorial etiological profile, and the myriad causes each have to be treated based on the symptoms and physical examination findings, while aiming to unload the stresses on the patellofemoral joint and peri-articular soft tissues. A weak quadriceps has been shown to not only contribute to increased joint stresses, but also increase the risk of cartilage loss in the patellofemoral and tibiofemoral compartments [ 27 ]. There is now evidence to indicate that quadriceps weakness may be more significant in progression of patellofemoral arthritis in women.…”