Effect of Blood Flow Restriction Therapy Following Achilles Rupture and Repair: A Randomized Controlled Trial
Authors: Hansen Oliver B. , Papson Andrea , Eble Stephanie K. , Drakos Mark C. 
Published: January 2022

Category: Sports; Other Introduction/Purpose: Blood flow restriction (BFR) therapy involves the use of a tourniquet to partially occlude blood flow to the affected limb, creating an anaerobic environment during exercise. This is thought to stimulate growth and recovery by increasing the body's anabolic response. BFR therapy can be initiated shortly after surgery since it allows for significant muscle activation with limited load bearing. To date, no existing study has evaluated the effect of using BFR therapy for recovery following Achilles tendon rupture and repair, after which patients often experience significant losses in calf strength and girth. This is a randomized controlled trial designed to study whether BFR can minimize loss of calf strength and muscle volume after Achilles rupture compared to a conventional physical therapy protocol. Methods: Patients presenting with an acute Achilles tendon rupture were randomized into the BFR or control group. Patients in the control group performed at-home exercises and began in-person physical therapy at 6 weeks postoperatively, as is the standard of care in our practice. The exercises were standardized across groups with BFR the isolated variable. The primary outcome studied was ankle plantarflexion strength as measured during isokinetic strength testing 3 months after surgical repair. We also tested knee strength during flexion and extension. All strength tests were performed at two rotational speeds. Calf atrophy was assessed by measuring the circumference of both calves 15 cm below the joint line at the time of operation and at 2 weeks, 6 weeks, 3 months, and 6 months postoperatively. Finally, Patient-Reported Outcome Measurement Information System (PROMIS) scores were collected pre- and postoperatively. Results: The study enrolled 43 patients, 24 of whom were assigned to the BFR group. 30 patients completed strength testing at 3 months and 26 at 6 months. Calf measurements through 3 months were completed for 39 patients and 6 month measurements were completed for 32 patients. Results for ankle plantarflexion strength at 3 months are displayed in Table 1, showing that patients in the BFR group demonstrated greater absolute strength in the operative calf compared to the control group, but no significant advantage in strength relative to the uninvolved calf. We failed to detect a significant difference in strength between groups for ankle dorsiflexion, knee extension, or knee flexion. Our model of calf circumference over time showed that BFR had a positive but insignificant correlation to calf circumference (p = 0.59). The only factors that demonstrated a significant (p<0.05) positive relationship to calf circumference were male sex and BMI. Conclusion: We have observed significant advantages in the BFR group when analyzing absolute calf strength metrics when compared to a randomized control group. This indicates that, when used during rehabilitation following Achilles rupture, BFR therapy may increase the strength of the operative leg and may facilitate recovery and outcome.