Blood Flow Restriction Training in Rehabilitation Following Anterior Cruciate Ligament Reconstructive Surgery: A Review

An examination of acute physiological and perceptual responses following blood flow restriction exercise using a traditional research device or novel, automated system

Objective. To compare the acute physiological and perceptual responses to blood flow restriction (BFR) exercise using a traditional research device or novel, automated system.Methods. Forty-four resistance trained individuals performed four sets of unilateral elbow flexion exercise (30% one-repetition maximum) to volitional failure using two distinct restrictive devices [SmartCuffs PRO BFR Model (SMARTCUFF), Hokanson E20 Rapid Inflation device (HOKANSON)] and with two levels of BFR [40% limb occlusion pressure (LOP), 80% LOP]. Blood pressure (BP), muscle thickness (MT), and isometric strength (ISO) were assessed prior to and following exercise. Perceptual responses [ratings of perceived exertion (RPE), discomfort] were assessed prior to exercise and following each exercise set.Main results. Data are displayed as means (SD). Immediately following exercise with 40% LOP, there were no statistical differences between devices for BP, MT, and ISO. However, only following Set 1 of exercise, RPE was greater with SMARTCUFF compared to HOKANSON (p< 0.05). In addition, only following Set 2 of exercise, discomfort was greater with HOKANSON compared to SMARTCUFF (p< 0.001). Immediately following exercise with 80% LOP, there were no statistical differences between devices for BP, MT, and ISO. However, only following Set 4 of exercise, RPE was greater with HOKANSON compared to SMARTCUFF (p< 0.05). In addition, following all exercise sets, discomfort was greater with HOKANSON compared to SMARTCUFF (p< 0.001). For repetitions completed with 40% LOP there were no statistical differences between SMARTCUFF and HOKANSON across any exercise sets. For repetitions completed with 80% LOP there were no statistical differences between SMARTCUFF and HOKANSON across Set 1 of exercise (p= 0.34), however, for Sets 2-4 of exercise, significantly greater number of repetitions were completed during SMARTCUFF than HOKANSON.Significance. The present study provides valuable insight into the efficacy of a novel, automated BFR system (SMARTCUFF) eliciting comparable acute physiological responses to BFR exercise and in some cases favorable perceptual responses when compared to a traditional research device (HOKANSON).

Nurse-Assisted Rehabilitation Protocols Following Anterior Cruciate Ligament Reconstruction

Despite significant advancements in surgical instruments and operation skills, short- and long-term outcomes following anterior cruciate ligament reconstruction (ACLR) remain unsatisfactory, as many patients fail to return to their pre-injury level of sports. Inadequate ACL rehabilitation is the primary cause of poor outcomes. Nurses have become a crucial element in the rehabilitation process. Although there is no consensus regarding the optimal post-operative rehabilitation protocols, restoring muscle strength and neuromuscular control are consistently the primary goals. This literature review presents nurse-assisted rehabilitation protocols aiming at improving muscle strength and neuromuscular control. The review discusses postoperative rehabilitation, including home-based and supervised rehabilitation, open and closed kinetic chain exercises, eccentric and concentric training, blood flow restriction training, and plyometric training. Each training protocol has its benefits and drawbacks, and should be used cautiously in specific stages of rehabilitation. Neuromuscular training, such as neuromuscular electrical stimulation, neuromuscular control exercises, and vibration therapy, is considered crucial in rehabilitation.

Early- and Late-Stage Benefits of Blood Flow Restriction Training on Knee Strength in Adolescents After Anterior Cruciate Ligament Reconstruction

Background

Blood flow restriction training (BFRT) after anterior cruciate ligament reconstruction (ACLR) is rising in popularity because of its benefits in reducing muscle atrophy and mitigating knee strength deficits.

Purpose

To investigate the impact BFRT has on adolescent knee strength after ACLR at 2 postoperative time points: at 3 months and the time of return to sport (RTS).

Study Design

Cohort study; Level of evidence, 3.

Methods

A prospective intervention (BFRT) group was compared to an age-, sex-, and body mass index-matched retrospective control group. Patients aged 12 to 18 years who underwent primary ACLR with a quadriceps tendon autograft were included. Along with a traditional rehabilitation protocol, the BFRT group completed a standardized BFRT protocol (3 BFRT exercises performed twice weekly for the initial 12 weeks postoperatively). Peak torque values for isometric knee extension and flexion strength (at 3 months and RTS) and isokinetic strength at 180 deg/s (at RTS) as well as Pediatric International Knee Documentation Committee (Pedi-IKDC) scores were collected. Differences between the BFRT and control groups were compared with 2-way mixed analysis of variance and 1-way analysis of variance.

Results

The BFRT group consisted of 16 patients (10 female; mean age, 14.84 ± 1.6 years) who were matched to 16 patients in the control group (10 female; mean age, 15.35 ± 1.3 years). Regardless of the time point, the BFRT group demonstrated significantly higher isometric knee extension torque compared to the control group (2.15 ± 0.12 N·m/kg [95% CI, 1.90-2.39] vs 1.74 ± 0.12 N·m/kg [95% CI, 1.49-1.98], respectively; mean difference, 0.403 N·m/kg; P = .024). The BFRT group also reported significantly better Pedi-IKDC scores compared to the control group at both 3 months (68.91 ± 9.68 vs 66.39 ± 12.18, respectively) and RTS (89.42 ± 7.94 vs 72.79 ± 22.81, respectively) (P = .047).

Conclusion

In adolescents, the addition of a standardized BFRT protocol to a traditional rehabilitation protocol after ACLR significantly improved knee strength and patient-reported function compared to a traditional rehabilitation program alone.

Update on Current Concepts of Blood Flow Restriction in the Perioperative Period of Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament tears or ruptures are common orthopedic injuries. Anterior cruciate ligament reconstruction (ACLR) is an orthopedic procedure allowing for earlier return to sports, improved maintenance of lifestyle demands, and restored knee stability and kinematics. A perioperative rehabilitative adjunct recently gaining interest is blood flow restriction (BFR), a method in which temporary restriction of blood flow to a chosen extremity is introduced and can be used as early as a few days postoperative. There has been increasing investigation and recent literature regarding BFR. This review synthesizes current concepts of BFR use in the ACLR perioperative period. [Orthopedics. 2023;46(6):e333-e340.].

Clinic and Home-Based Exercise with Blood Flow Restriction Resolves Thigh Muscle Atrophy after Anterior Cruciate Ligament Reconstruction with the Bone-Patellar Tendon-Bone Autograft: A Case Report

Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.

The Evolution of Rehabilitation and Return to Sport Following Cartilage Surgery

Rehabilitation after knee cartilage repair or restoration can be a challenging and nuanced process. Historically, conservative rehabilitation protocols have been characterized by limited weightbearing and restricted range of motion (ROM) were created to primarily protect the repaired cartilage but did little for progression into higher level activity. Recent literature has supported accelerated protocols in a variety of cartilage procedures ranging from osteochondral allograft (OCA) Osteochondral autograft surgery (OATS) to matrix-based scaffolding procedures such as Matrix Induced Chondrocyte Implantation (MACI) or Denovo procedures. Advances in technology such as blood flow restriction (BFR) and testing equipment with progressive rehabilitation from the acute phase through the return to sport continuum have made it possible to return to a higher level of activity and performance than first thought of for these procedures. This clinical viewpoint discusses the evolution of knee cartilage rehabilitation characterized by early but progressive weightbearing and early ROM while maintaining early homeostasis in the knee, and then its progression to return to sport and performance in the higher-level athlete.

Level of evidence

V.

Graft-Specific Surgical and Rehabilitation Considerations for Anterior Cruciate Ligament Reconstruction with the Quadriceps Tendon Autograft

Anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autograft has traditionally been the preferred surgical treatment for patients returning to Level 1 sports. More recently, international utilization of the quadriceps tendon (QT) autograft for primary and revision ACLR has increased in popularity. Recent literature suggests that ACLR with the QT may yield less donor site morbidity than the BPTB and better patient-reported outcomes than the HT. Additionally, anatomic and biomechanical studies have highlighted the robust properties of the QT itself, with superior levels of collagen density, length, size, and load-to-failure strength compared to the BPTB. Although previous literature has described rehabilitation considerations for the BPTB and HT autografts, there is less published with respect to the QT. Given the known impact of the various ACLR surgical techniques on postoperative rehabilitation, the purpose of this clinical commentary is to present the procedure-specific surgical and rehabilitation considerations for ACLR with the QT, as well as further highlight the need for procedure-specific rehabilitation strategies after ACLR by comparing the QT to the BPTB and HT autografts.

Level of Evidence

Level 5.

Time to Save Time: Beneficial Effects of Blood Flow Restriction Training and the Need to Quantify the Time Potentially Saved by Its Application During Musculoskeletal Rehabilitation

The main goal of musculoskeletal rehabilitation is to achieve the pre-injury and/or pre-surgery physical function level with a low risk of re-injury. Blood flow restriction (BFR) training is a promising alternative to conventional therapy approaches during musculoskeletal rehabilitation because various studies support its beneficial effects on muscle mass, strength, aerobic capacity, and pain perception. In this perspective article, we used an evidence-based progressive model of a rehabilitative program that integrated BFR in 4 rehabilitation phases: (1) passive BFR, (2) BFR combined with aerobic training, (3) BFR combined with low-load resistance training, and (4) BFR combined with low-load resistance training and traditional high-load resistance training. Considering the current research, we propose that a BFR-assisted rehabilitation has the potential to shorten the time course of therapy to reach the stage where the patient is able to tolerate resistance training with high loads. The information and arguments presented are intended to stimulate future research, which compares the time to achieve rehabilitative milestones and their physiological bases in each stage of the musculoskeletal rehabilitation process. This requires the quantification of BFR training-induced adaptations (eg, muscle mass, strength, capillary-to-muscle-area ratio, hypoalgesia, molecular changes) and the associated changes in performance with a high measurement frequency (≤1 week) to test our hypothesis. This information will help to quantify the time saved by BFR-assisted musculoskeletal rehabilitation. This is of particular importance for patients, because the potentially accelerated recovery of physical functioning would allow them to return to their work and/or social life earlier. Furthermore, other stakeholders in the health care system (eg, physicians, nurses, physical therapists, insurance companies) might benefit from that with regard to work and financial burden.

Rehabilitation and Return to Play Following Meniscus Repair

Injuries to the meniscus, particularly tears, can have significant negative impacts on pain, function, and quality of life. Preservation of the meniscus is favorable, especially in the athletic and active populations. While first line treatment is often nonoperative in nature, recalcitrant, and more complex tears, typically require surgery. Meniscus repair rates have increased significantly during the last 2 decades as surgical techniques and postoperative outcomes have improved. Longer postoperative timeframes are to be expected when compared with menisectomy, however, accelerated programs have demonstrated favorable outcomes. Rehabilitation and return to play guidelines should reflect the intricacies of the tear type and repair procedure. Close communication with the surgeon is a vital component to optimize patient outcomes. Further, the patient's goals and expected level of return to function, or sport, must be taken into account for a rehabilitation program to be fully successful.

Rehabilitation outcomes and parameters of blood flow restriction training in ACL injury: A scoping review

OBJECTIVE

To identify the outcomes of physical function, physical fitness, training, and cuff parameters, used in BFRT in ACL rehabilitation.

METHODS

This scoping review was initiated on April 25th, 2020, according to the PRISMA Extension for Scoping Reviews (PRISMA-ScR). Relevant literature was identified searching three main concepts: BFRT, rehabilitation and ACL injury on MEDLINE (PubMed), CENTRAL of Cochrane Library, Web of Science and PEDro. Studies looking at adults with a primary ACL injury undergoing conservative or pre/post-surgery rehabilitation with BFR or BFRT, with physical fitness and physical function as outcomes or other physical outcomes were included.

RESULTS

Sixty-eight articles were identified and six were included. One article was added through backward tracking. All studies used BFRT in the ACL injury surgical rehabilitation. Most studies evaluated physical fitness (muscular strength and volume) however, physical function was not considered a primary outcome. Training and cuff parameters were heterogeneously prescribed.

CONCLUSION

The existing evidence is not enough to draw definitive conclusions due to the heterogenous reported outcomes and parameters. Future investigation with standardized outcome measures and specific protocols are needed to draw conclusions on patients' physical function, so BFRT can be used more effectively in clinical rehabilitation practice.

Physical preparation and return to performance of an elite female football player following ACL reconstruction: a journey to the FIFA Women's World Cup

ACL injuries are among the most severe knee injuries in elite sport, with a high injury burden and re-injury risk. Despite extensive literature on the injury and the higher incidence of injury and re-injury in female athletes, there is limited evidence on the return to sport (RTS) of elite female football players following ACL reconstruction (ACLR). RTS is best viewed on a continuum aligning the recovery and rehabilitation process with the ultimate aim — a return to performance (RTP_erf). We outline the RTS and RTP_erf of an elite female football player following ACLR and her journey to the FIFA Women’s World Cup, including the gym-based physical preparation and the on-pitch/sports-specific reconditioning. We used the ‘control–chaos continuum’ as a framework for RTS, guiding a return above pre-injury training load demands while considering the qualitative nature of movement in competition. We then implemented the ‘RTP_erf pathway’ to facilitate a return to team training, competitive match play and a RTP_erf. Objective information, clinical reasoning and shared decision-making contributed to this process and helped the player to reach her goal of representing her country at the FIFA Women’s World Cup.

Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial

BACKGROUND

We implemented a blood flow restriction resistance training (BFR-RT) intervention during an 8-week rehabilitation programme in anterior cruciate ligament reconstruction (ACLR) patients within a National Health Service setting.

OBJECTIVE

To compare the effectiveness of BFR-RT and standard-care traditional heavy-load resistance training (HL-RT) at improving skeletal muscle hypertrophy and strength, physical function, pain and effusion in ACLR patients following surgery.

METHODS

28 patients scheduled for unilateral ACLR surgery with hamstring autograft were recruited for this parallel-group, two-arm, single-assessor blinded, randomised clinical trial following appropriate power analysis. Following surgery, a criteria-driven approach to rehabilitation was utilised and participants were block randomised to either HL-RT at 70% repetition maximum (1RM) (n = 14) or BFR-RT (n = 14) at 30% 1RM. Participants completed 8 weeks of biweekly unilateral leg press training on both limbs, totalling 16 sessions, alongside standard hospital rehabilitation. Resistance exercise protocols were designed consistent with standard recommended protocols for each type of exercise. Scaled maximal isotonic strength (10RM), muscle morphology of the vastus lateralis of the injured limb, self-reported function, Y-balance test performance and knee joint pain, effusion and range of motion (ROM) were assessed at pre-surgery, post-surgery, mid-training and post-training. Knee joint laxity and scaled maximal isokinetic knee extension and flexion strength at 60°/s, 150°/s and 300°/s were measured at pre-surgery and post-training.

RESULTS

Four participants were lost, with 24 participants completing the study (12 per group). There were no adverse events or differences between groups for any baseline anthropometric variable or pre- to post-surgery change in any outcome measure. Scaled 10RM strength significantly increased in the injured limb (104 ± 30% and 106 ± 43%) and non-injured limb (33 ± 13% and 39 ± 17%) with BFR-RT and HL-RT, respectively, with no group differences. Significant increases in knee extension and flexion peak torque were observed at all speeds in the non-injured limb with no group differences. Significantly greater attenuation of knee extensor peak torque loss at 150°/s and 300°/s and knee flexor torque loss at all speeds was observed with BFR-RT. No group differences in knee extensor peak torque loss were found at 60°/s. Significant and comparable increases in muscle thickness (5.8 ± 0.2% and 6.7 ± 0.3%) and pennation angle (4.1 ± 0.3% and 3.4 ± 0.1%) were observed with BFR-RT and HL-RT, respectively, with no group differences. No significant changes in fascicle length were observed. Significantly greater and clinically important increases in several measures of self-reported function (50-218 ± 48% vs. 35-152 ± 56%), Y-balance performance (18-59 ± 22% vs. 18-33 ± 19%), ROM (78 ± 22% vs. 48 ± 13%) and reductions in knee joint pain (67 ± 15% vs. 39 ± 12%) and effusion (6 ± 2% vs. 2 ± 2%) were observed with BFR-RT compared to HL-RT, respectively.

CONCLUSION

BFR-RT can improve skeletal muscle hypertrophy and strength to a similar extent to HL-RT with a greater reduction in knee joint pain and effusion, leading to greater overall improvements in physical function. Therefore, BFR-RT may be more appropriate for early rehabilitation in ACLR patient populations within the National Health Service.