619 - Bane or Boon- A rare complication of blood flow restriction therapy: A case report

Case Diagnosis: Proximal rectus femoris tear during blood flow restriction therapy

Case Description: An otherwise healthy 35-year-old male had a fall in 2019 resulting in persistent knee pain and was diagnosed with patellar mal-tracking syndrome. He underwent arthroscopic lateral retinacular release. He continued to have issues with pain and ultimately underwent patellectomy. Post procedure, he was prescribed physical therapy (PT) for knee pain and started blood flow restriction therapy which resulted in a “popping” sensation in the right hip. He initially received injections to the psoas as the etiology was thought to be from inflammation and pathology in his hip. He reportedly developed a foot drop after the injection. Pelvic MRI was negative for nerve compression but showed proximal rectus femoris tear at the myotendinous junction. Foot drop gradually improved with PT and he ultimately underwent surgical repair for the proximal rectus femoris tear

Discussions: BFRT is overall a very safe and beneficial treatment modality in post operative patients. In a study done by Cognetti et al. (2022) there was upto a 33% decrease in quadriceps muscle at three weeks post anterior cruciate ligament reconstruction (ACLR). Low load BFRT was effective at improving muscular size and strength over standard rehabilitation. Patients also had decreased knee pain and effusions compared to standard rehabilitation. Most common adverse events were muscle soreness and temporary paresthesia. More serious events in the literature are rhabdomyolysis and syncope. While overall still a safe modality and ideal in a patient that underwent arthroscopy, this is the first mention, in the literature, of a muscle tear as a direct result of BFRT.

Conclusions:

While BFRT has been theorized to reduce joint loading, there is still the possibility of adverse events and in this case injury to proximal muscles