People who have Anterior Cruciate Ligament (ACL) reconstruction surgery may benefit from a therapy known as blood flow restriction (BFR), according to a new study.
BFR refers to the application of external pressure (for example using a blood pressure cuff) to maintain arterial inflow while occluding venous outflow of blood distal to the occlusion site. This reduces oxygen delivery to muscle cells during low-resistance exercise and is believed to promote muscle hypertrophy while reducing pain and adverse joint loading.
Immediately after ACL repair, patients often face bone and muscle loss. However, researchers presenting their work at the recent Specialty Day hosted by the American Orthopaedic Society for Sports Medicine (AOSSM) and the Arthroscopy Association of North America (AANA) reported that combining BFR therapy with traditional rehabilitation efforts may slow bone loss and reduce return to function time.
“Providing BFR as part of the rehabilitation efforts following ACL surgery appears to help preserve the bone, recover muscle loss and improve function quicker, according to our research,” said lead author Dr Bradley Lambert from Houston Methodist Hospital.
Dr Lambert and colleagues conducted a randomised prospective study involving a group of active young patients who underwent ACL reconstruction.
Participants were divided into two groups and all received the same rehab protocol, but one group exercised with an 80% arterial limb occlusion using an automated tourniquet for some exercises.
Measurements of bone mineral density, bone mass and lean muscle mass showed that the addition of BFR therapy to standard rehab exercises prevented muscle mass loss in the whole leg and thigh in the post-operative limb compared to rehab alone. What’s more, it minimised losses in bone mineral content and preserved bone density in the limb compared to standard rehab alone.
These findings coincided with improved functional outcomes.
“BFR is a suitable additive therapy to ACL rehabilitation for the purposes of minimising the loss, and enhancing the recovery of muscle, bone, and physical function,” Dr Lambert said. “While further research is needed to fully illuminate the physiologic mechanisms responsible for our results, these findings likely have wide ranging implications for fields outside of ACL rehab alone such as injury prevention, age-related muscle and bone loss, military rehabilitation, and potentially space flight.”