Effects of Blood Flow Restriction Combined With Electrostimulation After Knee Arthroplasty: Randomized Controlled Trial

Blood flow restriction (BFR) is an innovative treatment technique that involves the application of controlled pressure, through a special sleeve, to partially limit arterial flow and completely prevent venous outflow in the active muscles during exercise.

This approach is based on a hemodynamic modulation that induces a hypoxic environment at the muscle level, favoring the activation of metabolic processes and cellular mechanisms responsible for positive adaptations, such as the increase in protein synthesis, the promotion of muscle hypertrophy, aerobic capacity and the management of pain perception.

In rehabilitation, blood flow restriction treatment has been recognized as an effective strategy to promote functional recovery, offering benefits comparable to those of traditional treatment with high loads. This methodology is particularly useful in contexts where the use of high loads is contraindicated, such as in patients with orthopaedic limitations, with muscle weakness or undergoing surgery because it induces significant muscle adaptation even with low loads. The latest evidence indicates that reduced Limb occlusion pressures (LOP) (40% of blood pressure) achieve similar benefits to high pressures (80%) and are appreciated by patients. In the middle-aged and elderly population, the efficacy of BFR has been widely demonstrated but the studies that have investigated its effects on patients undergoing Knee Arthroplasty (KA) are few, of poor quality and carried out in the advanced rehabilitation phase. Patients undergoing KA at the "Città di Pavia" University Hospital, from the first post-operative day, perform a standard rehabilitation program including: passive mobilization, assisted active exercises, indirect electrostimulation and gait re-education. Although the results are positive, in the first few days, there are cases in which problems such as loss of muscle strength and functionality and persistence of pain occur; these sequelae are in agreement with the most recent literature.

Based on the rationale, the study aims to evaluate, in a group of patients undergoing KA, the short-term effects of electrostimulation combined with BFR and compare them with those of a group that will carry out the standard treatment. The treatment steps will be as follows:

I. positioning of electrodes for electrostimulation on the quadriceps of the operated limb; II. application of the pneumatic band to the root of the thigh and LOP setting; III. programmazione dei parametri della BFR (LOP, 50%) (Occlusion time, 6 periods of 4 minutes of occlusion and 1 minutes of rest); IV. simultaneous start-up of the two devices.