Pulsed Electromagnetic Field Therapy on Muscle Strength and Function in Patients With End-stage of Knee Osteoarthritis

End-stage OA knee is one of the most common musculoskeletal complaints, with over 34,000 patients waiting for joint replacement in Hong Kong and is expected to increase as the population continues to age constantly. The nominal waiting time for joint replacement in Hong Kong is long compared with many developed countries, averaging at 122 months, resulting in many elderly patients living with severe pain, limiting their daily activities. We are, therefore, in dire need to improve the well-being of this large and increasing group of patients as the capacity for operations remains limited. It is important to maintain preoperative knee-extensor strength in the end-stage of knee OA awaiting TKR because the improvement of knee-extensor strength may postpone the need for surgery and increase the ability to perform functional activities after TKR at the same time. PEMF exposure, on top of regular exercise training, may promote the secretion of myokine and in turn, promote muscle regeneration. These findings laid grounds for implementing PEMF treatment for end-stage knee OA patients to enhance muscle regeneration in periods with limited physical activity. The novelty of this study is that this is the first RCT to examine if pulsed electromagnetic field therapy (PEMF), in addition to a standard rehabilitation, produces better muscle strength and functional performance before and after TKR in people with knee OA than either intervention alone. The impact of this study is particularly strong given end-stage patients waiting for knee replacement surgeries in Hong Kong.