BFRT vs Standard PT After Total Knee Arthroplasty

Background Blood flow restriction training (BFRT) uses a specialized tourniquet system to restrict arterial inflow and venous outflow to the limb during low-load resistance exercise. BFRT has the potential to augment strength gains for rehabilitation patients who are unable to tolerate high intensity resistance training.

Objective To determine if BFRT will accelerate the recovery of thigh muscle function and strength in post-operative TKA compared to a standard post-operative rehabilitation protocol.

Primary Outcome Measures:

Quadriceps Strength: dynamometry (hand held)

Secondary Outcomes Measures:

Patient Reported Outcomes Knee Injury and Osteoarthritis Outcome Score, Jr Veterans Rand -12 Functional Measures Timed stair ascent Four square Test 5x Sit to Stand Test

Study Design Open label randomized clinical trial with a 1:1 allocation in random sized blocks

Sample Size Based on a Pre-TKA Quadriceps Maximal Voluntary Isometric Contraction mean of 18 with a standard deviation of 8, expecting a 20% improvement of MVIC with BFRT compared to standard Physical Therapy, with an α of 0.05 and β of 0.20 (80% power), the sample size is 63 in each arm. To account for a 20% drop-out rate, a total of 75 subjects will be enrolled in each arm Study Arms Control arm: Subjects will receive American College of Sports Medicine guided-strength training Experimental: Subjects will receive BFRT strength training as part of their post-operative physical therapy program for two months during normal post-op rehab.

Background Blood flow restriction training (BFRT) uses a specialized tourniquet system to restrict arterial inflow and venous outflow to the limb during low-load resistance exercise. BFRT has the potential to augment strength gains for rehabilitation patients who are unable to tolerate high intensity resistance training.

Objective To determine if BFRT will accelerate the recovery of thigh muscle function and strength in post-operative TKA compared to a standard post-operative rehabilitation protocol.

Primary Outcome Measures:

Quadriceps Strength: dynamometry (hand held)

Secondary Outcomes Measures:

Patient Reported Outcomes Knee Injury and Osteoarthritis Outcome Score, Jr Veterans Rand -12 Functional Measures Timed stair ascent Four square Test 5x Sit to Stand Test

Study Design Open label randomized clinical trial with a 1:1 allocation in random sized blocks

Sample Size Based on a Pre-TKA Quadriceps Maximal Voluntary Isometric Contraction mean of 18 with a standard deviation of 8, expecting a 20% improvement of MVIC with BFRT compared to standard Physical Therapy, with an α of 0.05 and β of 0.20 (80% power), the sample size is 63 in each arm. To account for a 20% drop-out rate, a total of 75 subjects will be enrolled in each arm

Study Arms Control arm: Subjects will receive American College of Sports Medicine guided-strength training Experimental: Subjects will receive BFRT strength training as part of their post-operative physical therapy program for two months during normal post-op rehab.

Eligibility Criteria:
Inclusion Criteria:

* Status post primary TKA and cleared by surgeon for Physical Therapy.
* Ages 50-79 years old
* Able to participate fully in PT
* Primary cruciate retaining or posterior stabilized TKA.
* Knee Range of Motion of surgical extremity is a minimum of 5° on full extension to 90° on full flexion

  • Exclusion Criteria:
* Unable to consent for study participation
* Unable to participate in preoperative testing
* Any ligamentous or osseous reconstruction at time of surgery that limits weight bearing
* History of Deep Vein Thrombosis
* Injury or recent procedure to uninvolved extremity within 6 months
* History of endothelial dysfunction
* History of Peripheral Vascular Disease including varicose veins
* Easy bruisability
* TKA is revision
* History of surgical wound complication on involved extremity
* History of stroke
* History of dementia
* History of neuromuscular disorder
* History of Chronic Obstructive Pulmonary Disease
* History of diabetes mellitus with neuropathy
* History of previous intra-articular fracture of involved extremity causing surgical fixation
* History of sickle cell trait/disease
* Previous participation in BFRT
* Any surgical procedure affecting their ability to complete all PT sessions or testing.
* History of functionally limiting arthritis in non-surgical Lower Extremity
* Prior contralateral Total Knee Arthroplasty
* Prior Total Hip Arthroplasty
* Positive pregnancy test
* Enrollment into another clinical research trial