Effects of a multi-modal resistance and impact exercise program on knee cartilage structure, cartilage defects and bone marrow lesions in older adults-An 18-month randomised controlled trial.

Abstract

Introduction: Osteoporosis and osteoarthritis (OA) often coexist in older adults, and questions remain whether bone loading exercises are harmful to joints. This study examined the effects of an 18-month, progressive resistance training (PRT) and impact exercise (Impact-Ex) program, which we have shown improved in hip and spine bone density, on knee cartilage volume (CV), cartilage defects (CD) and bone marrow lesions (BMLs) in older adults at falls/fracture risk. CDs and BMLs were assessed as they are linked to cartilage loss and may be indicative of incipient OA. Method(s): 162 adults (60+y) were randomised to Ex (n = 81) consisting of PRT+Impact-Ex (60-180 impacts/session) 3/week or usual-care (UC, n = 81). Knee MRI scans were used to assess tibial CV, CDs [tibiofemoral (TF) and patella] and TF BMLs. Average weekly PRT volume and impact loads were correlated with changes in cartilage health. Result(s): 150 participants completed the study. Tibial CV loss was not significantly different between Ex and UC (medial -2.5% vs -1.5%, P = 0.27; lateral -3.2% vs -2.5%, P = 0.33), nor was progression of CD (TF medial, 14% vs 15%; lateral 26% vs 28%; patella 12% vs 19%) and BMLs (TF medial 14% vs 17%; lateral 7% vs 5%). CV loss was no different between groups according to baseline CDs or BMLs. Average weekly PRT volume and number of impacts were not related to changes in cartilage volume. Key Conclusion(s): A multi-modal resistance and impact exercise program was safe and effective for improving bone health in older adults, with no adverse effects on knee cartilage structure.