Biomechanical markers associations with pain, symptoms, and disability compared to radiographic severity in knee osteoarthritis patients: a secondary analysis from a cluster randomized controlled trial

Abstract

Background Conventional radiography is commonly used to diagnose knee osteoarthritis (OA), but also to guide clinical decision-making, despite a well-established discordance between radiographic severity and patient symptoms. The incidence and progression of OA is driven, in part, by biomechanical markers. Therefore, these dynamic markers may be a good metric of functional status and actionable targets for clinicians when developing conservative treatment plans. The aim of this study was to assess the associations between biomechanical markers and self-reported knee function compared to radiographic severity. Methods This was a secondary analysis of data from a randomized controlled trial (RCT) conducted in primary care clinics with knee OA participants. Correlation coefficients (canonical (ρ) and structural (Corr)) were assessed between the Knee Injury and Osteoarthritis Outcome Score (KOOS) and both, radiographic OA severity using the Kellgren-Lawrence grade, and three-dimensional biomechanical markers quantified by a knee kinesiography exam. Significant differences between coefficients were assessed using Fischer’s z-transformation method to compare correlations from dependent samples. Results KOOS and biomechanical data were significantly more associated than KOOS and X-ray grading (ρ: 0.41 vs 0.20; p < 0.001). Structural correlation (Corr) between KOOS and X-ray grade was 0.202 (4% of variance explained), while individual biomechanical markers, such as the flexion during loading, explained up to 14% of KOOS variance (i.e., Corr2). Biomechanical markers showed the strongest associations with Pain and Activity of Daily Living KOOS subscales (both > 36% variance explained), while X-ray grading was most associated with Symptoms subscale (21% explained; all p ≤ 0.001). Conclusions Knee biomechanical markers are associated with patient-reported knee function to a greater extent than X-ray grading, but both provide complementary information in the assessment of OA patients. Understanding how dynamic markers relate to function compared to radiographic severity is a valuable step towards precision medicine, allowing clinicians to refine and tailor therapeutic measures by prioritizing and targeting modifiable biomechanical markers linked to pain and function. Trial registration Original RCT was approved by the Research Ethics Boards of École de technologie supérieure (H20150505) and Centre hospitalier de l’Université de Montréal (CHUM-CE.14.339), first registered at https://www.isrctn.com/ (ID-ISRCTN16152290) on May 27, 2015.

Association of the Degree of Varus Thrust during Gait Assessed by an Inertial Measurement Unit with Patient-Reported Outcome Measures in Knee Osteoarthritis

“…For example, Fukutani et al performed multivariable regression analyses to adjust for confounding factors and reported that VT rated by experts was independently associated with the Japanese Knee Osteoarthritis Measure score (a type of PROMs) [ 15 ]. Additionally, Bensalma et al found that a larger VT assessed quantitatively using the varus angle during the stance phase measured using a three-dimensional motion analysis system was associated with lower KOOS scores [ 19 ]. However, several other reports did not find an association between VT and PROMs [ 9 , 12 , 20 ].…”

“…Among the KOOS scores, significant associations with VT were found for the pain, symptoms, and ADL scores after adjusting for potential confounders, but not for the Sport and QoL scores in this study. The study by Bensalma et al also showed that larger VT was associated with lower pain, symptoms, and ADL KOOS scores [ 19 ]. These results agree with our results, although the Sport and QoL scores were not reported.…”

“…As walking is the most performed form of physical activity [ 17 , 18 ], the abnormal gait patterns in patients with knee OA could cause unbalanced mechanical stress on the knee joint, worsening of symptoms, and loss of ability. A few studies have examined the association between the degree of VT and PROMs in patients with knee OA [ 19 , 20 ]. Although a study reported that a larger VT assessed using a three-dimensional motion analysis system was associated with worse PROMs [ 19 ], other studies reported that no association was observed between the degree of VT and PROMs [ 20 ]; thus, the association remains unclear.…”

“…A few studies have examined the association between the degree of VT and PROMs in patients with knee OA [ 19 , 20 ]. Although a study reported that a larger VT assessed using a three-dimensional motion analysis system was associated with worse PROMs [ 19 ], other studies reported that no association was observed between the degree of VT and PROMs [ 20 ]; thus, the association remains unclear. Clarifying this association would provide clinicians with the impetus to develop effective interventions for PROMs.…”

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“…29,30 There may also be varying degrees of muscle pathology, a high rate of muscle protein degradation and muscle volume losses, related problems that stem from damage or dysfunction of the joint sensory and motor nerves, muscle inhibition and/or weakness, plus evidence of increasing postural instability in weight bearing joints. [31][32][33][34][35][36][37] In addition, an immense loss of functional independence, motivation for self-care, a loss of independence, and a declining belief in their ability to overcome their life challenges are cognitive factors that may be expected to increasingly exacerbate the older adults pain, 38 and overall multiple biomechanical disease impacts. 39 As such, if an older adult suffering from various degrees of osteoarthritis wants to remain in the community, rather than reside in a nursing home, their goals can probably only be met if concerted efforts are made to assess if this is feasible, for example if they have mild-moderate rather than severe forms of the disease, and if so to carefully and insightfully assess their past medical history, and current health and disease status, and address and plan for their immediate, short term and long term needs accordingly, bearing in mind the more recently acknowledged need to keep older adults as healthy as possible and protected against COVID infections and their oftentimes dire repercussions.…”