Effects of Passive Blood-Flow-Restriction on Muscle Atrophy and Pain After Elective Total Knee Arthroplasty

BFR training involves the application of blood flow restriction during passive or active movement interventions to elicit an additional metabolic stimulus. The cuffs are applied as proximally as possible on the thigh, and a pressure is exerted during the movement that partially restricts venous return from the limb, resulting in venous pooling. Venous occlusion is achieved using a cuff system commonly employed in resistance training (Delfi Medical Innovations Inc., Vancouver, Canada; CE-certified). The pressure applied is individually determined at the start of each training session based on the participant's arterial occlusion pressure, measured via duplex ultrasonography. For this measurement, the participant rests in a supine position while the cuff is gradually inflated until no blood flow is detectable in the limb (i.e., occlusion pressure). For the BFR intervention, 60-80% of this occlusion pressure is subsequently applied. The exercise protocol consists of daily

Patients in the control group (CG) follow the same exercise protocol as those in the BFR intervention group; however, the cuff is only inflated to a minimal pressure of 20 mmHg. This pressure does not induce any relevant venous stasis, nor can any local or systemic metabolic effects be expected.