| Abstrakt: |
Objective: Traumatic knee injury is a substantial risk factor for osteoarthritis, with changes in articular cartilage often evident on MRI within 1 year. The purpose of this study was to compare the response to a dynamic loading stimulus, as measured by changes in pain and tibiofemoral cartilage MRI T2 relaxation, in patients with a history of knee injury and healthy controls. Methods: We recruited 10 patients (7 ACL rupture, 2 traumatic meniscal tear, 1 cartilage lesion), and 10 healthy controls. We obtained T2 maps before and after the loading stimulus using 3T MRI. We segmented articular cartilage using 3D Slicer. Following the scan, all participants completed the loading stimulus, consisting of 25 minutes of walking on an instrumented, dualbelt treadmill, including changes in speed, inclines and declines, lateral sways, and random pre-specified perturbations. Patients were asked to report pain on a scale of 0-10 before and after the loading stimulus, as well as rating of perceived exertion (RPE, Borg Scale) at three points throughout. Results: Mean RPE was 11.5±1.6 for patients and 10.4±2.3 for controls (mean difference 1.1, 95%CI -0.8, 3.0). The patients experienced a significant increase in pain (1.5, 95%CI 0.6, 2.4) following the loading stimulus, while all healthy controls reported no pain at all timepoints. T2 decreased by 1.9±1.5 ms in patients and 1.9±1.3 ms in controls (mean difference 0.0, 95%CI -1.3, 1.3). Conclusion: Patients with a history of traumatic knee injury experience significant increases in pain with dynamic loading compared to healthy controls despite similar RPE and cartilage load response. Clinical implications: Clinical guidelines suggest patients who experience knee pain exercise within limits that increase their pain score by no more than 2 points. These results suggest that moderate intensity exercise with changes in pain within those limits causes no additional stress to the articular cartilage compared to healthy controls. [ABSTRACT FROM AUTHOR] |
