The investigators aim to study the use of blood flow restriction therapy (BFR) to augment routine post-operative physical therapy in elderly patients (age >= 65) after recovering from surgical treatment of hip fractures.

For elderly patients, a hip fracture is a life-altering event associated with poor overall outcomes despite early surgical treatment. The elderly population and those with significant osteopenia is growing exponentially and thus the optimal treatment and rehabilitation of hip fractures warrants increased investigation. Despite numerous interventions, falls plague the elderly population and hip fractures remain a very common problem for this population that needs to be addressed. Rapid deconditioning plays a significant role in patient morbidity following hip surgery. Recently, blood flow restriction (BFR) treatment has been shown to be effective in improving muscle strength when combined with low load resistance training physical therapy programs in elderly patients. Few studies have examined BFR in post-operative orthopedic trauma patients. The investigators aim to study the use of BFR to augment post-operative physical therapy in elderly patients (age >= 65) in the first 2-weeks after recovering from surgical treatment of hip fractures. Due to the profound muscle atrophy that occurs in the immediate postoperative period because of immobility and disuse, the investigators hypothesize that BFR may provide an anabolic effect and conserve muscle strength. The investigators hypothesis was inspired by the findings of the Nobel Prize in Physiology 2019 which describes how varying levels of oxygen shape both physiology and pathology. This is a prospective, randomized blinded 2-week study of elderly patients recovering from surgical treatment of hip fractures with two arms: 1) routine post-op physical therapy 2) routine physical therapy + BFR and neuromuscular electrical stimulation (NMES) beginning on postoperative day 1 and occurring 5 days per week for 2 weeks. To optimize safety, the study will be in an inpatient-only setting and supervised by team members certified in the application of BFR. The investigators plan to apply lessons learned to a larger 8-week intervention upon completion of this short-term pilot study. To our knowledge, this is the first study to use BFR in postoperative geriatric patients. Main outcomes will include thigh leg circumference on postoperative day 1 and at the end of week 2, adverse event log for complications, knee extension strength via handheld dynamometry (HHD) at post-op day 1 and week 2, gait speed, functional tests including timed up and go, opioid MME (morphine milligram equivalent) consumption and patient perceived pain and quality of life measures. The investigators anticipate BFR therapy will be tolerated well, improve global patient health and satisfaction, lead to lower extremity muscle hypertrophy, and enhance functional recovery after geriatric hip fracture carrying tremendous potential for extramural funding and scientific advancement.

Inclusion Criteria:

• Age >= 65 years old, any sex, any ethnicity
• Isolated, closed proximal femur fracture without any prior surgery or orthopedic implants to affected proximal femur. This includes all fractures with primary fracture line that is proximal to the lesser trochanter. For example, subtrochanteric femur fractures are excluded whereas reverse obliquity intertrochanteric femur fractures may be included.
• OTA codes 31A, 31B, and 31C
• Segmental and pathologic femur fractures are excluded.
• Ambulatory without assistive device prior to injury
• Community living prior to injury
• No injury or surgery to the contralateral lower extremity within past 1 year
• Alert and oriented and able to provide informed consent for self
• English speaking
• Able to weight bear as tolerated after surgery as deemed by treating orthopedic surgeon
• Able to tolerate light exercise (could walk approximately 0.5 mile without significant pain or shortness of breath) preoperatively as determined by patient self-reported history

Exclusion Criteria:

• Presence of other significant injuries at the time of injury to the proximal femur that would require additional surgery
• Significant delay in presentation to health care facility (>3 days from time of injury) for assessment and treatment of the proximal femur fracture
• History of DVT in any extremity, existing DVT in any extremity, or any condition known to increase risk for coagulopathy including but not exclusively current pregnancy, current diagnosis of cancer/cancer that is being treated
• Current use of any medication or supplement that may increase blood clotting risk
• History of: sickle cell anemia, peripheral arterial disease, dementia, actively treated cancer
• Varicose veins in either lower extremity
• Any significant medical condition that would preclude ability to bear weight as tolerated postoperatively
• Significant cardiac disease as defined by recent stent placement in the past year or presence of implantable pacemaker device
• Morbid obesity (BMI >40)
• Prior surgery to either lower extremity within one year
• Prior surgery or injury to either lower extremity that would preclude application of a tourniquet and includes but not exclusively: skin grafting, vascular bypass grafting, dialysis site, chronic wound, lymphotomies, varicose vein surgery, presence of tumor)
• Soft tissue injury to either lower extremity that precludes placement of tourniquet
• Diagnosis of uncontrolled hypertension (BP greater than 180/110 on at least two measurements as measured during inpatient stay before surgery)
• Patients with potentially severe problems with maintaining follow-up (ex. Patients who are prisoners, homeless at time of injury, severe dementia, intellectually challenged without adequate family support or have documented significant psychiatric disorder)
• COVID-19 positive
• Admission to ICU postoperatively
• Inadequate postop x-rays placing patient at high risk of implant-related failure

To be determined.

The control group will undergo a graduated therapy protocol that mirrors that of the intervention group except that they will use a Delfi tourniquet system blood pressure cuff with a limb occlusion pressure (LOP) of only 10%. This is compared to the intervention group that will have a therapeutic LOP of 60-100%. This means that patients will have a cuff on their limb and are thus blinded to their group allocation but the pressure is set to such a low level that no additional effect on muscle hypertrophy is expected based on prior research.