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Trial registered on ANZCTR


Registration number
ACTRN12624001221549p
Ethics application status
Not yet submitted
Date submitted
15/09/2024
Date registered
8/10/2024
Date last updated
8/10/2024
Date data sharing statement initially provided
8/10/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Effect of low load Blood Flow Restriction (BFR) exercise on postoperative outcomes after knee ligament reconstruction
Scientific title
Blood Flow Restriction (BFR) in ACL reconstruction rehabilitation: A randomised controlled pilot study looking at BFR effect on quadriceps and hamstring strength in the first 6 months following ACL reconstruction surgery in 16 - 50 years old participants.
Secondary ID [1] 312914 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anterior cruciate ligament rupture 335078 0
Condition category
Condition code
Musculoskeletal 331582 331582 0 0
Other muscular and skeletal disorders
Physical Medicine / Rehabilitation 331800 331800 0 0
Other physical medicine / rehabilitation
Injuries and Accidents 331801 331801 0 0
Other injuries and accidents

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Blood Flow Restriction (BFR) training will be the intervention applied to the treatment arm of this trial. Pressure will be set to 80 percent limb occlusion pressure (LOP) at rest.
Patients randomized to the BFR cohort receive personalized limb occlusion pressure (LOP) measured using a Doppler ultrasound placed on the dorsalis pedis pulse by the physiotherapist administering the BFR. The LOP will be checked every 2 weeks. Patients in the BFR group are provided a single-chamber manual pneumatic torniquet (BFR.co) when performing pre-habilitation exercises. The limb occlusion pressure should be set to 80% unless the participant reports undesirable pain scores (>5 on a 10 point visual analog scale) associated with the starting cuff pressure around the thigh, then the pressure should be reduced in 10% increments until VAS pain scores are a 5 or less. LOC below 50% would trigger an exclusion of the patient from the BFR study as ‘cuff intolerance’.

Before surgery, all patients indeterminant of treatment group will complete a home exercise program by a physiotherapist. The home exercise program consisted of exercises performed 5 times a week for the 2 weeks before surgery as a form of ‘‘prehabilitation.’’ Exercises included quadriceps contractions in end-range extension, straight-leg raises, long-arc quadriceps sets, and quarter squats. All exercises were performed for 75 repetitions with a repetition scheme of 30-15-15-15, allowing for 30 seconds of rest between sets. Patients were educated on how to properly perform the required exercises and were asked to sign a log (exercise diary) that would be returned during the preoperative visit to demonstrate compliance.

BFR training will occur twice weekly beginning 2 weeks following surgery and concluding at 12 weeks post operatively. The BFR training will be carried out in accordance with a 2020 study (Humes et al., 2020). In utilizing BFR therapy, a standard postoperative rehabilitation protocol will be implemented following the guidelines outlined in the Melbourne ACL Rehabilitation Guide.

The pneumatic cuff will be placed more proximal than distal to mitigate neurovascular injury. In addition, for the traditional strengthening BFR exercises, four sets should be performed with reps of 30/15/15/15 including 30 second rest interval between each set with the BFR cuff still inflated.
After the completion of exercise, the cuff is deflated for one minute to allow for reperfusion before continuing with the strengthening exercise. The load resistance would be determined preoperatively at 30 percent of maximum resistance during 1 repetition (1RM).
At the 3-month mark, patients were progressed to usual heavy-resistance training and BFR was discontinued.

Instead of using percentage repetition maximum, the loads will be adjusted within the first session to meet either the desired repetition scheme or time under tension.

A brief description of the postoperative rehabilitation protocol is as follows:

Phase One – 0-6 Weeks
Overview: Phase One, the protected phase, starts in the first week post-op (after day three). Goals include pain control, reducing joint effusion, restoring range of motion, and maintaining muscular and aerobic endurance.

BFR Usage: Max 25 minutes. The participants are only required to wear the cuff during the rehabilitation sessions. Exercises are divided into three subsets: weeks 1-2, weeks 2-4, and weeks 4-6.

Weeks 1-2:

Neuromuscular Electrical Stimulation: 10-20% max voluntary contraction for 10 minutes (10 sec contraction, 20 sec rest). Pads placed on vastus lateralis and vastus medialis oblique.
Exercises:
Isometric holds (60-90 degrees flexion).
Hip adduction (initially no weights, then cuff weights).
Bent knee ankle plantar flexion (increase resistance as tolerated).
Straight leg raises (begin with no weights, add cuff weights as needed).
Weeks 2-4:

Continue previous exercises unchanged.
New Exercises:
Prone hip extension (initially no weights, then cuff weights).
Long arc quad (30-90 degrees, no weights until week four).
Weeks 4-6:

Continue straight leg raises, side-lying hip abduction, and long arc quad with same protocols.
New Exercises:
Bilateral bridging (avoid joint line pain).
Leg presses (0-60 degrees, 25% body weight).
Phase Two – 6-12 Weeks
Focus: Strengthening for normal weight-bearing gait and full range of motion. Exercises at ~30% of one-rep max to prevent atrophy and promote hypertrophy.

Weeks 6-10:

Exercises:
Leg presses (25% body weight or 30% one-rep max).
Resisted hamstring curls (30% one-rep max).
Exercise bike (15 minutes at resistance level 3).
Weeks 10-12:

Continue exercise bike for endurance.
New Exercises:
Squatting (regular and split) at 30% one-rep max.
Phase Three – After 12 Weeks (up to 24 weeks post-operative)
Transition: Begins at three months post-ACL reconstruction, moving from HIIT to BFR training until HIIT can be done without pain. Gradually wean off BFR until exclusively performing HIIT.

Direct observation of the participants during their rehabilitation sessions will be carried out by the treating physiotherapist in order to assess and monitor adherence.

The overall trial duration will be 24 weeks.
Intervention code [1] 329459 0
Rehabilitation
Intervention code [2] 329576 0
Treatment: Devices
Comparator / control treatment
In the control group, the same cuffs are employed and the same exercise’s are performed with an absolute pressure of to 20 mmHg to allow all the exercises to be performed with the cuff on with no significant occlusion.
Patients will follow the same BFR rehab protocol as above.
The intervention and control groups train separately performed either with a trained physiotherapist or exercise physiologist.
Control group
Dose comparison

Outcomes
Primary outcome [1] 339329 0
Maximal voluntary contraction strength of the knee extensors
Timepoint [1] 339329 0
Preoperatively and postoperatively at 6 weeks, 12 weeks and 24 weeks post surgery. The change in strength between each time point will be determined for each patient.
Primary outcome [2] 339437 0
Maximal voluntary contraction strength of the knee flexors
Timepoint [2] 339437 0
Preoperatively and postoperatively at 6 weeks, 12 weeks and 24 weeks post surgery. The change in strength between each time point will be determined for each patient.
Secondary outcome [1] 439519 0
Muscle morphology
Timepoint [1] 439519 0
Preoperatively and postoperatively at 6 weeks, 12 weeks, and 24 weeks post surgery.
Secondary outcome [2] 439520 0
Physical Function
Timepoint [2] 439520 0
Preoperatively and postoperatively at 6 weeks, 12 weeks and 24 weeks post surgery.
Secondary outcome [3] 439977 0
Knee function
Timepoint [3] 439977 0
Preoperatively and postoperatively at 6 weeks, 12 weeks and 24 weeks post surgery.
Secondary outcome [4] 439978 0
Knee pain at rest
Timepoint [4] 439978 0
Preoperatively and postoperatively at 6 weeks, 12 weeks and 24 weeks post surgery.

Eligibility
Key inclusion criteria
Between 16 and 50 years old.
ACL injury without concomitant injury requiring post-operative limited weight bearing status or hinge knee brace.
Graft choice: Hamstring autograft.
Willingness to participate and provide consent.
Minimum age
16 Years
Maximum age
50 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Previous significant trauma or surgery to the affected leg.
Significant comorbidity (haemophilia, diabetes, cardiac condition, respiratory condition, etc.).
Concomitant surgery requiring limited weight bearing status post operatively e.g. meniscal repair/ chondral injury requiring NWB status, multi-ligament reconstruction.
Patients receiving quadriceps or patella tendon grafts.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Will be done by the study coordinator. Participants will randomly be assigned to either the 80 percent occlusion or 20mmHg by usage of the US National Cancer Institute website's online randomisation tool (ctrandomization.cancer.gov/home/). The group the participant is placed in will be provided to the participants’ physiotherapist. The physiotherapist must not let the participant know if they are in the high or ‘sham’ cuff group.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation). Participants will randomly be assigned to either the 80 percent occlusion or 20mmHg by usage of the US National Cancer Institute website's online randomisation tool (ctrandomization.cancer.gov/home/).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/12/2024
Actual
Date of last participant enrolment
Anticipated
1/02/2025
Actual
Date of last data collection
Anticipated
1/12/2025
Actual
Sample size
Target
30
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
TAS

Funding & Sponsors
Funding source category [1] 317346 0
Charities/Societies/Foundations
Name [1] 317346 0
Clifford Craig Foundation
Country [1] 317346 0
Australia
Primary sponsor type
Individual
Name
Jonathan Mulford- Tamar Valley Orthopaedics
Address
Country
Australia
Secondary sponsor category [1] 319834 0
Individual
Name [1] 319834 0
Laurent Willemot
Address [1] 319834 0
Country [1] 319834 0
Australia

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 316076 0
University of Tasmania Human Research Ethics Committee
Ethics committee address [1] 316076 0
Ethics committee country [1] 316076 0
Australia
Date submitted for ethics approval [1] 316076 0
18/10/2024
Approval date [1] 316076 0
Ethics approval number [1] 316076 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 136702 0
Prof Jonathan Mulford
Address 136702 0
Tamar Valley Orthopaedics: 77 Elphin Road, Launceston Tasmania 7250
Country 136702 0
Australia
Phone 136702 0
+61 0421604299
Fax 136702 0
Email 136702 0
[email protected]
Contact person for public queries
Name 136703 0
Jonathan Mulford
Address 136703 0
Tamar Valley Orthopaedics: 77 Elphin Road, Launceston Tasmania 7250
Country 136703 0
Australia
Phone 136703 0
+61 03 6388 9250
Fax 136703 0
Email 136703 0
[email protected]
Contact person for scientific queries
Name 136704 0
Jonathan Mulford
Address 136704 0
Tamar Valley Orthopaedics: 77 Elphin Road, Launceston Tasmania 7250
Country 136704 0
Australia
Phone 136704 0
+61 03 6388 9250
Fax 136704 0
Email 136704 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?




Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.