# Clinical characteristics and physical activity levels of patients with knee osteoarthritis with and without a previous knee injury: A cross-sectional study

## TL;DR

This study compares older adults with knee osteoarthritis who had or hadn't previously injured their knee, finding that those without prior injury had lower physical activity and worse health outcomes.

## Contribution

The study identifies distinct differences in physical activity and health outcomes between knee osteoarthritis patients with and without prior knee injuries.

## Key findings

- Patients without prior knee injury had lower daily steps and worse pain and mobility scores.
- Those with prior injury showed better physical function and higher activity levels despite similar radiographic OA severity.
- Age and sex adjustments confirmed the PTOA group's better health outcomes independent of demographics.

## Abstract

To compare clinical characteristics and physical activity levels of patients with mild-to-moderate knee osteoarthritis (OA).

A total of 262 individuals with mild-to-moderate knee OA recruited from the Technology, Exercise Programming, and Activity Prescription for Enhanced Mobility (TEAM) Study (NCT04544904) were categorized into two groups: 1) no previous knee injury (NTOA group), or 2) previous knee injury (PTOA group). We collected participants’ demographics, Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, Arthritis Self-Efficacy questionnaire, Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire, previous sport participation, radiographic OA features, and medical history. A smartphone application measured daily steps and self-reported physical activity levels were measured using the Global Physical Activity Questionnaire. A 30-s chair-stand and 40-m walk test assessed physical function.

The NTOA group was older (62.3 ± 9.0 vs. 58.2 ± 7.4 years, p < 0.05) and had lower daily steps (4372 ± 263 vs. 5776 ± 445 steps, padj < 0.05) and previous sport participation (62.6 % vs. 81.7 %, p < 0.05) than the PTOA group. Anthropometric measurements, sex, radiographic OA scores, comorbidities, smoking, and alcohol consumption were not different. The NTOA group had lower KOOS Pain (58.0 ± 1.2 vs. 64.3 ± 2.1, padj < 0.05) and Activities of Daily Living (65.6 ± 1.3 vs. 73.9 ± 2.3, padj < 0.05), higher ICOAP (44.2 ± 1.6 vs. 34.7 ± 2.8, padj < 0.05), longer 40-m walk times (27.1 ± 0.4 vs. 24.1 ± 0.7 s, padj < 0.05) and lower 30-s chair-stand repetitions (12.1 ± 0.4 vs. 14.3 ± 0.7, padj < 0.05).

The PTOA group had higher daily steps and better physical and psychological health status than the NTOA group, independent of age and sex. Physical activity interventions may benefit those with NTOA more given their lower activity and greater symptomatology.