Evaluation of femoral cartilage thickness after walking on treadmill and tartan track in healthy and knee osteoarthritis individuals

The aim of this study is to measure femoral cartilage thickness change in healthy individuals and patients with knee osteoarthritis (OA) after treadmill and tartan track walking and to compare whether there is a difference in acute cartilage thickness change between healthy individuals and patients with knee OA. Thirty patients over the age of 40, who were admitted to Pamukkale University Physical Medicine and Rehabilitation Outpatient Clinic, diagnosed with knee OA according to the American College of Rheumatology (ACR) criteria, and had stage 1-2 according to KellgrenLawrence staging criteria and 30 healthy individuals matched for age and gender were included in the study. The sociodemographic characteristics and detailed medical history of the participants included in the study were questioned and recorded. Upon detailed physical examination of all participants, their body mass index (BMI) was calculated by measuring their weight and height. Participants' physical activity levels were determined based on the World Health Organization's Global Physical Activity Questionnaire (GPAQ). A repeated measures design was used in which healthy individuals and patients with knee OA all completed all loading conditions (30 min. walking on a treadmill and tartan track). Therefore, both healthy individuals and patients with knee OA initially underwent treadmill walking, followed by tartan track walking one week later. Femoral cartilage thickness was measured by portable ultrasonography (USG) (Clarius L7 HD Linear Scanner) before and immediately after walking. All post-loading USG procedures were acquired within 5 minutes of the loading condition. The study findings indicated a statistically significant decrease in the medial femoral condyle, intercondylar and lateral femoral condyle cartilage thickness after both treadmill and tartan track walking when compared to the prewalking measurements in healthy individuals (p<0.001); this decrease after treadmill walking was found to be statistically higher than after tartan track walking (p<0.001). After walking on both the treadmill and tartan track, there was a statistically significant decrease in the medial femoral condyle, intercondylar and lateral femoral condyle XIII cartilage thickness compared to pre-walking measurements in patients with knee OA (p<0.001). In patients with knee OA, the decrease in only the medial femoral condyle cartilage thickness after treadmill walking was found to be statistically higher than the decrease after tartan track walking (p<0.05). After both treadmill and tartan track walking, a statistically higher decrease in the medial femoral condyle, intercondylar and lateral femoral condyle cartilage thickness was found in healthy individuals compared to patients with knee OA (p<0.001). In conclusion, femoral cartilage thickness decreased after both treadmill and tartan track walking in both healthy individuals and patients with knee OA, with the reduction in all compartments being less pronounced in healthy individuals and limited to the medial femoral condyle in patients with knee OA after tartan track walking compared to treadmill walking. Tartan track walking caused less cartilage thickness change in the knee joint compared to treadmill walking. In order to interpret the clinical significance of these results, further studies are needed to determine the threshold of physiologic adaptation and the threshold of pathologic deformation in femoral cartilage thickness reduction caused by mechanical loading.