Use of Blood Flow Restriction Therapy in Perioperative Rehabilitation Following Achilles Tendon Rupture

The purpose of this study is to examine the effect of utilizing blood flow restriction (BFR) therapy in the rehabilitation of Achilles tendon rupture (ATR). Muscle atrophy occurs following Achilles tendon rupture, whether managed non operatively or operatively, which has implications on patient outcomes. The goal of physical therapy in the perioperative period is to regain and ultimately return to activity. BFR has been proposed to reduce atrophy and maintain strength, which would theoretically mitigate the deconditioning effects of an injury on surrounding musculature. BFR is proposed to work by restricting arterial inflow leading to an oxygen depleted environment and the ability to induce muscle adaption at lower maximum repetition via reactive hyperemia and induction of growth cytokines, thus leading to muscle hypertrophy.

The goal of this investigation is to determine if using BFR as an adjunct in physical therapy following ATR would reduce muscular atrophy and lead to increased and expedited strength gains. Additionally, the investigators would like to determine if BFR accelerates the rehabilitation process and allows patients to perform standard rehabilitative functional tests and return to play sooner. Furthermore, the investigators will investigate patient reported outcomes metrics.

The investigators hypothesize that the BFR group will have significantly greater strength gains at all time points in both non operatively and operatively treated ATR. Previous studies have shown that BFR has potential in increasing Achilles tendon stiffness, tendon cross-sectional area, muscle strength and muscle hypertrophy. However, there is a lack of evidence regarding the use of BFR in both the pre and postoperative period specifically relating to ATR. The investigators believe that the use of BFR in the perioperative period surrounding an Achilles tendon rupture and ATR has the potential to significantly decreased muscle atrophy, improve patient satisfaction and lead to earlier return to sport.

Following diagnosis of ATR, attending surgeons will discuss treatment options with the patient and determine their course of treatment to be operative or non-operative. Patients will then be randomized via computer to prospectively undergo ATR rehabilitation using conventional therapy or conventional therapy with a BFR adjunct by physical therapists already trained in BFR with extensive experience in ATR rehabilitation. There will be no incentive provided for participation by the therapists and the therapists may opt out of using BFR at any point. Treatment groups will undergo similar protocols with the only difference being the use of BFR as an adjunct to their rehabilitation. The protocol for using the BFR cuff will be similar to previous studies examining BFR in lower extremity injuries, with adaptation to the postoperative protocol specific to the Achilles tendon. More specifically the physical therapists will be provided with a tourniquet that includes a pressure monitor. The skin will be protected with a sleeve and the cuff will be placed in the thigh well proximal to the knee joint. The investigators will begin by determining the patient's limb occlusion pressure, which is conducted automatically by the cuff via built in doppler. Once this is done the cuff will be inflated to 80% of the limb occlusion pressure, which is the currently accepted recommendation in the literature and sufficient to achieve the desired effect of blood flow restriction.

For non-operative candidates the investigators will begin their rehabilitation and physical therapy immediately following their initial office visit. Participants will have follow-up appointments at two-weeks, six-weeks, three-months and six-months. During these follow-up appointments the investigators will assess calf strength, calf circumference, ankle range of motion, current pain and function level. Additionally, the investigators will conduct testing at the end of the therapy sessions to ensure patients are prepared to return to sports.

For operative candidates the investigators will schedule their surgery at the earliest convenience and availability following their initial office visit. Participants will begin their rehabilitation and physical therapy immediately following their surgery. Participants will have follow-up appointments at two-weeks, six-weeks, three-months and six-months. During these follow-up appointments the investigators will assess calf strength, calf circumference, ankle range of motion, current pain and function level. Additionally, the investigators will conduct testing at the end of the therapy sessions to ensure patients are prepared to return to sports.

In both operative and non-operative rehabilitation, therapy will consist of a structured program progressing from range of motion to strength training and then functional tests. Both those randomized to conventional therapy and those randomized to conventional therapy with BFR adjunct will follow the same protocol with the only variable being the use of BFR. Again, the BFR group will have the cuff inflated per protocol outlined above, this will be under the guidance of trained physical therapists.

Throughout this protocol patient will have their initial/pre-operative visit to establish care and set up surgery and follow-up appointments at two-weeks, six-weeks, three-months and six-months. All data collection and testing during these follow-up appointments will be obtained with a handheld device and will add less than five minutes to clinic visits.

Eligibility Criteria:
Inclusion Criteria:

* patients aged 18-65 who suffered an achilles tendon rupture.
* Patients with achilles tendon rupture that are being treated operatively and non-operatively.

Exclusion Criteria:

* undergoing a revision procedure
* other concomitant injuries of the same leg
* have a history of deep vein thrombosis
* peripheral vascular disease
* neurovascular injury to the extremity
* are unable to tolerate BFR treatment
* have a leg circumference greater than the largest available tourniquet circumference of 96.52 cm
* unable to complete physical therapy.