Changes in medial-to-lateral knee joint loading patterns assessed by Dual-Energy X-ray Absorptiometry following supervised neuromuscular exercise therapy and patient education in patients with knee osteoarthritis: an exploratory cohort study

ABSTRACT

Background

The mechanisms underlying pain reductions following exercise therapy in patients with knee osteoarthritis (OA) are poorly understood. One mechanism could be changes in mechanical knee joint loading.

Objective

To investigate if a neuromuscular exercise therapy and patient education intervention could alter knee joint loading assessed by Dual-Energy X-ray Absorptiometry (DXA) in people with knee OA.

Methods

Participants with symptomatic knee OA were evaluated before and 26 weeks after an 8-week supervised neuromuscular exercise therapy and patient education intervention (Good Life with OsteoArthritis in Denmark). DXA scans were used to estimate the medial-to-lateral tibial plateau bone mineral density (BMD) ratio. The Knee Injury and Osteoarthritis Outcome Score was used to assess improvements in knee pain, symptoms, physical function, and knee-related quality of life. Changes in physical function were assessed with the 30-second chair stand test and the 40-meter fast paced walk test.

Results

Of 42 participants recruited, 30 (21 females, mean age 64 $\pm$ 7.9 years) had full data available. Medial-to-lateral tibial BMD ratio increased non-significantly by 0.02 (95% CI −0.01 to 0.06) (indicating higher medial load) from baseline to 26-weeks follow-up. Participants had statistically significant improvements of 21% in pain, 17% in symptoms, 14% in ADL, 17% in knee-related quality of life, 13% in chair stand ability, and 6% in walking speed.

Conclusions

In this exploratory cohort study, following an 8-weeks supervised exercise therapy and patient education intervention, the medial-to-lateral tibial BMD ratio did not seem to change.

KEYWORDS:

• Knee osteoarthritis
• bone mineral density
• exercise
• biomechanics
• Dual-Energy X-ray Absorptiometry

Disclosure statement

One of the authors (EMR) is the developer of the Knee Injury and Osteoarthritis Outcome Score. Two of the authors (EMR and STS) are the founders of Good Life with osteoArthritis in Denmark.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website

Additional information

Funding

This work was supported by the Independent Research Fund Denmark [Grant number 9058-00008B]. The initiation of GLA:D® was partly funded by the Danish Physiotherapy Association’s fund for research, education and practice development; the Danish Rheumatism Association; and the Physiotherapy Practice Foundation.