Efficacy of low-load blood flow restricted resistance EXercise in patients with Knee osteoarthritis scheduled for total knee replacement (EXKnee): protocol for a multicentre randomised controlled trial

[Blood flow restriction training (BFRT) in patients before and after total knee arthroplasty]

BACKGROUND

In healthy individuals, blood flow restriction training (BFRT) has shown positive effects on muscle mass, strength, fatigue resistance, as well as tendon and bone metabolism. BFRT reduces blood flow in the extremities using inflatable cuffs, creating local muscular hypoxia, which produces an anabolic metabolic environment. This promotes significant muscular and cardiovascular adaptations even at low mechanical training loads.

KNEE ENDOPROSTHESES

BFRT also shows promising initial results in pre- and postoperative applications for knee endoprostheses (KTEP). Both preoperative and postoperative BFRT can improve muscle strength and joint function, accelerate recovery, and alleviate pain. Although the method is generally safe, potential risks such as discomfort and rare side effects must be considered. Clear application protocols are still lacking, necessitating further research and individualized programs to achieve optimal training effects. BFRT thus offers an innovative way to effectively rehabilitate patients despite their low load tolerance.

The effectiveness of low-load Blood flow restriction Exercise in patients with an acute Achilles tendon rupture treated Non-surgically (BEAN): Protocol for a randomized controlled trial

BACKGROUND

Blood flow restriction exercise (BFRE) has been proposed as a viable method for preserving muscle mass and function after an injury during periods of load restrictions such as after an acute Achilles tendon rupture. However, its effectiveness and safety in patients with an Achilles tendon rupture have yet to be evaluated in a randomized trial.

OBJECTIVES

First, to investigate the effectiveness of early initiated BFRE in patients with non-surgically treated acute Achilles tendon rupture. Second, to evaluate whether it is better to apply BFRE in the beginning (1-12 weeks) or later (13-24 weeks) in the rehabilitation period.

METHODS

This is an assessor-blinded, randomized, controlled multicenter trial with patients assigned in a 1:1 ratio to two parallel groups, that either receive BFRE in weeks 1-12 followed by usual care in weeks 13-24, or receive usual care in weeks 1-12 followed by BFRE in weeks 13-24. The BFRE program is performed three times weekly on the injured leg at 80 % of the pressure required to fully restrict the arterial blood flow. Post-intervention tests are conducted in week 13, comparing early BFRE with usual care, and in week 25, comparing early BFRE with late BFRE. At the 13-week evaluation, the primary outcome is the Single-Leg Heel-Rise test which assesses the patient's ability to raise the heel of the injured leg a minimum of 2 cm. At the 25-week evaluation, the primary outcome is the Achilles tendon Total Rupture Score which assesses the patient's self-reported symptoms and physical ability.

Efficiency assessment of follow-up methodology of patients with knee replacement to predict post-surgical functionality: a protocol for randomised control PROKnee trial

INTRODUCTION

Even when total knee arthroplasty (TKA) is an extended treatment, most patients experience a suboptimal evolution after TKA. The objectives of this study are the following: (1) to determine the effectiveness of two different prosthesis stabilisation systems on the functionality in activities of daily life, and (2) to determine prognostic biomarkers of knee prosthesis function based on radiological information, quantification of cytokines, intra-articular markers and biomechanical functional evaluation to predict successful evolution.

METHODS AND ANALYSIS

The PROKnee trial was designed as a randomised controlled patient-blinded trial with two parallel groups that are currently ongoing. The initial recruitment will be 99 patients scheduled for their first TKA, without previous prosthesis interventions in lower limbs, who will be randomly divided into two groups that differed in the stabilisation methodology incorporated in the knee prosthesis: the MEDIAL-pivot group and the CENTRAL-pivot group. The maximum walking speed will be reported as the primary outcome, and the secondary results will be patient-reported questionnaires related to physical status, cognitive and mental state, radiological test, laboratory analysis and biomechanical instrumented functional performance, such as the 6-minute walking test, timed up-and-go test, gait, sit-to-stand, step-over, and ability to step up and down stairs. All the results will be measured 1 week before TKA and at 1.5, 3, 6 and 12 months after surgery.

ETHICS AND DISSEMINATION

All procedures were approved by the Ethical Committee for Research with Medicines of the University Clinical Hospital of Valencia on 8 October 2020 (order no. 2020/181). Participants are required to provide informed consent for the study and for the surgical procedure. All the data collected will be treated confidentially since they will be blinded and encrypted. The results from the trial will be published in international peer-reviewed scientific journals, regardless of whether these results are negative or inconclusive.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04850300).

Sit-to-stand power predicts functional performance and patient-reported outcomes in patients with advanced knee osteoarthritis. A cross-sectional study

BACKGROUND

Lower limb muscle power is positively associated with functional performance and patient-reported outcomes (PROMs) and suggested as an important variable to evaluate in patients with advanced knee osteoarthritis (OA).

OBJECTIVES

To explore the association between muscle power derived from the 30-sec sit-to-stand test (STS power) with functional performance and PROMs compared to maximal isometric knee extensor strength (KE MVC) in male- and female patients with advanced OA.

STUDY DESIGN

Cross-sectional design.

METHODS

Eighty-six patients (66.6 [64.9-67.7]years) with advanced knee OA were included. Dependent variables were STS power and KE MVC. Independent variables were Timed Up&Go (TUG), 40-m fast-paced walk test (40mFWT), Knee injury and Osteoarthritis Outcome Score (KOOS) subscales.

COVARIATE

Age.

ANALYSES

Simple linear- and multiple regression analyses with and without adjusting for age. Pitman's test was used to evaluate differences in correlation strength among dependent variables.

RESULTS

STS power demonstrated a statistical relationship with TUG and 40mFWT for both sexes (β coefficients -1.11 to -4.36 (p < 0.05), r2 = 0.47-0.55 (p < 0.05)), and with KOOS Pain, ADL, and Sport for male patients (β coefficients 6.53 to 7.17 (p < 0.05), r2 = 0.29-0.33 (p < 0.05)). Knee extensor MVC demonstrated no relationship with any outcomes for male patients or female patients. STS power displayed statistically stronger correlation to functional performance.

CONCLUSION

STS power was associated with functional performance in both male patients and female patients suffering from advanced knee OA. Moreover, STS power was associated with KOOS Pain, Sport, and ADLin male patients. The assessment of STS power should be considered in the evaluation of patients with advanced knee OA.

TRIAL REGISTRATION NUMBER

NCT04081493.

Feasibility of Blood Flow Restriction Exercise in Adults with a Non-surgically Treated Achilles Tendon Rupture; a Case Series

Blood flow restriction exercise (BFRE) appears to provide a unique opportunity to preserve lower limb muscle and function in patients with an Achilles tendon rupture. The purpose of this study was to investigate the feasibility of BFRE in patients with an Achilles tendon rupture. Additionally, to evaluate muscle volume and patient-reported ankle function, symptoms, complications, and physical activity following 12 weeks of BFRE. Feasibility was measured by adherence to training sessions, drop-out rate, intervention acceptability, ankle pain exacerbation (NRS), and adverse events. At baseline and 12-weeks follow-up, patients completed the Achilles Tendon Total Rupture Score questionnaire and had their thigh and calf circumference measured. At follow-up, patients' ability to perform a single-leg heel rise was tested. Sixteen of 18 patients completed the intervention and for those, adherence to training sessions was 88% ±16%. The mean NRS following BFRE sessions was 1.1 (95%CI: 1; 1.2). Three adverse events occurred during the 12 weeks. Two re-ruptures after completion of the BFRE program and one deep venous thrombosis following cast removal. BFRE was found to be feasible in a subset of patients with an Achilles tendon rupture. However, with three adverse events in a population of 18 patients, the effectiveness and safety of BFRE warrants further investigation.

Physiological and clinical effects of low-intensity blood-flow restricted resistance exercise compared to standard rehabilitation in adults with knee osteoarthritis-Protocol for a randomized controlled trial

INTRODUCTION

Osteoarthritis (OA) is a common disease with high socioeconomical costs. In Denmark, standard rehabilitation (SR) consists of a combination of patient education and supervised physical exercise involving a standardized neuromuscular training program. As an evidence-based alternative, high-load (>70% 1RM) resistance training (HIRT) has shown positive rehabilitation effects in knee-OA but may not be tolerated in all patients (~25%) due to knee joint pain. However, low-load resistance training (20-40% 1RM) with concurrent partial blood-flow restriction (BFR) appears to produce effects similar to HIRT yet involving reduced joint pain during and after exercise. The aim is to examine the effect of low-load BFR training compared to SR on pain, thigh muscle mass and muscle function in adults with knee-OA. We hypothesize that 12 weeks of BFR will lead to superior improvements in pain, muscle mass and mechanical muscle function compared to SR.

METHODS AND ANALYSIS

90 participants diagnosed with radiographic knee-OA will be randomized to either BFR or SR twice a week for 12 weeks. BFR will consist of two selected lower limb strength exercises performed with an inflated pneumatic occlusion cuff. Intervention procedures in SR consist of a full 8 weeks GLA:D course followed by 4 weeks of team group training. Primary outcome variable is the change in KOOS-Pain subscale from baseline to 12 weeks. Secondary outcome variables are changes in pain sensitivity, functional performance, muscle mass and mechanical muscle function. Intention-to-treat and per-protocol analyses will be conducted. One-way analysis of variance will be performed to evaluate between-group changes. Pre-to-post intervention comparisons will be analyzed using a mixed linear model. Regression analysis will be performed to evaluate potential associations between selected outcome variables.

Effects of blood-flow restricted exercise versus conventional resistance training in musculoskeletal disorders-a systematic review and meta-analysis

OBJECTIVE

To compare the effect of low-load blood flow restricted resistance training (BFR-RT) versus high-load resistance training (HL-RT) on muscle strength, muscle mass, physical function, patient-reported outcomes, and adherence to training in clinical musculoskeletal populations.

DATA SOURCES

Web of Science, Cochrane Central, Medline, Embase, SportDiscus was searched on the 30th May 2022.

REVIEW METHODS

This study was conducted as a systematic review and meta-analysis. Randomized Controlled Trials (RCTs) were included if they (i) included patients, (ii) comprised of a BFR-RT intervention protocol and a group who performed HL-RT (≥ 70%1RM) for at least eight exercise sessions, and (iii) involved at least 1 exercise that targeted the lower limbs. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The meta-analyses were performed using a random effects model with an adjustment to the confidence interval.

RESULTS

Seven RCTs comprising 303 participants (BFR-RT: n = 151; HL-RT: n = 152) were identified. HL-RT and BFR-RT showed similar gains in dynamic (1-10RM) knee extensor strength and leg press strength, quadriceps cross sectional area, sit-to-stand performance, and patient reported pain and function. There was a moderate effect favoring BFR-RT for increasing maximal isometric knee extensor strength. The grading of certainty in evidence was low-to-very low for all outcome variables.

CONCLUSION

This systematic review and meta-analysis extends our current knowledge about BFR-RT and HL-RT as equally effective exercise methods for inducing gains in maximal muscle strength in healthy populations, by now also comprising patients suffering from various clinical musculoskeletal conditions. The certainty in the estimates was low-to-very low, prompting the inclusion of future higher-quality trials.

TRIAL REGISTRATION

PROSPERO ID (CRD42022337173). Registered June 18th 2022.

Low-load exercises with concurrent blood flow restriction as rehabilitation for unspecific knee pain to a former American football player: A case report

Former athlete, 30 years of age, suffered several months of moderate anterior knee pain during daily life activities where daily life activities such as negotiating stairs and lifting heavy objects were moderately painful. Magnetic resonance imaging showed normal meniscus and cruciate ligaments and no extra joint fluid. The patient was referred to a physiotherapist who introduced a strengthening program. Low-load resistance training with concurrent blood flow restriction can induce significant gains in maximal muscle strength and mass with minimal exacerbation of knee-joint pain. We describe the outcome of 12 weeks low-load resistance training with concurrent blood flow restriction as a rehabilitation method for anterior knee pain. The patient performed low-load resistance training with concurrent blood flow restriction for the lower limbs (goblet squat, single-leg knee extensions and flexions). After the low-load resistance training with concurrent blood flow restriction, the patient increased isometric knee extensor muscle strength (31%), single-leg hop test performance (23%), obtained clinically relevant improvements in patient-reported outcomes and was able to return to his usual high-loading training regime. Low-load resistance training with concurrent blood flow restriction seems promising to transition patients back to a healthy lifestyle of training and being physically active.

Low-Load Blood-Flow-Restricted Exercise to Prevent Muscle Atrophy and Decline in Functional Performance in a Patient Recovering From a Malleolus Fracture. A Case Report

This present case presentation offers supportive evidence that low-load blood-flow-restriction exercise (LL-BFRE) may be a feasible intervention to preserve skeletal muscle mass and, in part, lower-limb muscle function after a fracture of the lateral malleolus. A 28-year-old female patient sustained a radiographically verified stabile fracture of the lateral malleolus and was treated with a walker cast. She was allowed weight bearing on the limb within the limits of her pain threshold and to perform unloaded plantar and dorsiflexion movements of the ankle. The patient performed 12 weeks of home-based LL-BFRE 4 times per week to diminish declines in functional performance, muscle strength, and skeletal muscle atrophy. We observed that LL-BFRE was feasible with no exercise-related adverse events in the early stage of rehabilitation. The patient experienced no-or-low pain during exercise. Vastus lateralis muscle volume, and thigh and calf circumference was preserved.

Effect of Oral Tranexamic Acid on the Blood Transfusion Rate and the Incidence of Deep Vein Thromboembolism in Patients after TKA

Purpose

To explore the effect of oral tranexamic acid treatment on the blood transfusion rate and the incidence of deep vein thromboembolism after total knee arthroplasty (TKA).

Methods

90 patients undergoing TKA admitted to First People's Hospital of Changshu City from January 2019 to January 2020 were selected and randomized into the control group and the experimental group accordingly (45 cases in each group). The control group intravenously received 20 mL/kg tranexamic acid before the incision was closed. The experimental group was given 1 g of tranexamic acid orally before anesthesia, 6 h and 12 h after the operation.

Results

The experimental group witnessed better perioperative indexes in relation to the control group. The experimental group displayed better postoperative coagulation function indexes as compared to the control group (P < 0.05). Remarkably lower postoperative vascular endothelial function indexes in the experimental group than in the control group were observed. The experimental group experienced a markedly lower incidence of deep vein thromboembolism in comparison with the control group (P < 0.05). The postoperative knee society score (KSS) score of the experimental group was significantly higher than that of the control group. A significantly higher postoperative modified rivermead mobility index (MRMI) score was yielded in the experimental group in contrast to the control group (P < 0.05). The experimental group obtained lower numerical rating scale (NRS) scores at T2 and T3 as compared to the control group.

Conclusion

Oral tranexamic acid is a suitable alternative for patients undergoing TKA in terms of reducing the blood transfusion rate, relieving pain, and accelerating the recovery of the patient's limbs.

Effects of Resistance Training Prior to Total Hip or Knee Replacement on Post-operative Recovery in Functional Performance: A Systematic Review and Meta-Analysis

Objective

To evaluate the effectiveness of pre-operative resistance training in patients allocated to TJR surgery on selected post-operative outcomes, via a meta-analysis of studies using exercise modalities and loading intensities objectively known to promote gains in muscle size and strength in adults of young-to-old age.

Design

A systematic review and meta-analysis.

Literature Search

Cochrane Central, MEDLINE, EMBASE, and PEDro were searched on August 4th 2021.

Study Selection

Randomized Controlled Trials (RCTs) were included if (i) they compared pre-operative lower-limb-exercises before elective TJR with standard care, (ii) explicitly reported the exercise intensity, and (iii) reported data on functional performance.

Data Synthesis

This systematic review and meta-analysis is reported in accordance with the PRISMA reporting guidelines. A random effects model with an adjustment to the confidence interval was performed for pooling the data.

Results

One thousand studies were identified. After applying exclusion criteria, five RCTs were located including 256 participants (mean age ranged from 61 to 72 years, 54% women). Moderate-to-large improvements in functional performance and maximal knee extensor strength were observed at 3 months after surgery along with small-to-moderate effects 12 months post-operatively. For patient-reported outcomes, small-to-moderate improvements were observed at 3 months post-operatively with no-to-small improvements at 12 months.

Conclusion

Prehabilitation efforts involving progressive resistance training provides an effective means to improve post-operative outcomes related to functional performance, knee extensor strength and patient-reported outcome in patients undergoing TJR. Due to large methodological diversity between studies, an optimal loading intensity remains unknown.

Systematic Review Registration

Prospero ID: CRD42021264796.

Does Blood Flow Restriction Therapy Improve Leg Strength in Patients With a Painful Total Knee Arthroplasty?

BACKGROUND

Blood flow restriction (BFR) therapy has been proposed to help patients build strength with fewer repetitions than standard physical therapy (PT). We sought to determine if BFR would improve quadriceps and hamstring strength in patients with instability and perceived weakness >1 year after primary total knee arthroplasty (TKA).

METHODS

We retrospectively reviewed 48 patients with painful TKAs and flexion instability as well as quadriceps and hamstring weakness who performed a 6-week PT program and received isokinetic strength measurements (ISMs). Thirty-six patients completed a standard PT program (non-BFR) and 12 patients completed a BFR regimen. ISMs were taken before and after PT to quantify quadriceps and hamstring power, torque, and work compared to the contralateral leg. Statistical analysis was conducted on pre-PT and post-PT ISMs and decisions for revision surgery.

RESULTS

There were no differences in ISMs after PT between the BFR and non-BFR groups. The non-BFR group showed statistically significant strength improvements in flexion but not extension (+28.7%-32.8%, P = .0145-.255). Although no significant difference was found in the BFR group, they saw improvements in all extension strength metrics (19.4%-23.4%, P = .3315-.3901) and flexion (25.7%-29.9%, P = .1994-.2392). No difference was observed between the groups in the rates of subsequent revision TKA (8.3% vs 16.7%, P = .3362).

CONCLUSION

BFR did not improve quadriceps and hamstring strength compared to PT alone in patients with instability and weakness after TKA. Over 80% of total patients chose to avoid revision TKA after completion of focused PT with or without BFR.

Exercise With Low-Loads and Concurrent Partial Blood Flow Restriction Combined With Patient Education in Females Suffering From Gluteal Tendinopathy: A Feasibility Study

Introduction

To date, there exists no gold standard conservative treatment for lateral hip pain due to tendinopathy of the gluteus medius and/or minimus tendon (GT), a condition often complicated by pain and disability. Higher loads during everyday activities and exercise seems to be contraindicated with GT. The purpose of this study was to evaluate the feasibility of exercise with low-loads concurrent partial blood flow restriction (LL-BFR) and patient education for patients present GT.

Methods

Recruitment took place at three hospitals in the Central Denmark Region. The intervention consisted of daily sessions for 8 weeks with one weekly supervised session. From week three patients exercised with applied partial blood flow restriction by means of a pneumatic cuff around the proximal thigh of the affected leg. Throughout the intervention patients received patient education on their hip condition. Sociodemographic and clinical variables were collected at baseline. The feasibility of LL-BFR was conducted by adherence to the exercise protocol and drop-out rate. Patient reported outcome measures (The Victorian Institute of Sport Assessment-Gluteal Questionnaire, EuroQol - 5 Dimensions-Visual Analogue Scale, Oxford Hip Score, Copenhagen Hip and Groin Outcome Score), maximal voluntary isometric hip abduction-, hip extension, and knee extension strength (Nm/kg) measured using a handheld dynamometer, and functional capacity tests (30 second chair-stand test and a stair-climb test) was conducted as secondary outcomes.

Results

Sixteen women with a median (IQR) age of 51 (46–60) years were included. Median (IQR) Body Mass Index was 26.69 (23.59–30.46) kg/m2. Adherence to the total number of training sessions and the LL-BFR was 96.4 and 94.4%, respectively. Two patients dropped out due to (i) illness before initiation of LL-BFR and (ii) pain in the affected leg related to the LL-BFR-exercise. At follow-up both pain levels and patient-reported outcome measures improved. Isometric hip abduction-, hip extension-, and knee extension strength on both legs and functional performance increased. Conclusion: LL-BFR-exercise seems feasible for treatment of GT. At follow-up, a high adherence and low drop-out rate were observed. Further, patients reported clinically relevant reductions in pain, and showed significant increases in isometric hip and knee strength.

Effects of Low-Load Blood-Flow Restricted Resistance Training on Functional Capacity and Patient-Reported Outcome in a Young Male Suffering From Reactive Arthritis

Introduction: Reactive arthritis (ReA) is a chronic inflammatory disease usually caused by a preceding gastrointestinal or genitourinary bacterial infection. ReA usually occurs in the lower limbs causing joint pain and joint swelling. Physiotherapy-led exercise is recommended to prevent muscle atrophy. The purpose of this case report is to describe the outcome after 12 weeks of low-load blood flow restricted resistance training (BFR-RT) as a rehabilitation method for a young male suffering from ReA.

Methods and materials: A 17-year-old male suffered from ReA in the both knee joints and the left hip joint. 36 months after the incident, he suffered from another ReA incident in his right knee. Non-steroid anti-inflammatory drugs and a new arthrocentesis added with corticosteroid injection was unsuccessful in treating the ReA. The patient performed 12 weeks of BFR-RT on the right lower limb with a low amount of supervision after the first week of training. Assessment of unilateral 30-sec chair stand test (u30-sec CST), low-thigh circumference above apex patella, The Knee Injury and Osteoarthritis Outcome Score (KOOS), The Forgotten Knee Joint Score (FJS), and Numeric Ranking Scale for pain (NRS) was performed at baseline and after 3,6,9, and 12 weeks of BFR-RT.

Results: The patient completed all planned exercise sessions. u30-sec CST improved with 7 repetitions (reps) on the right limb and 5 reps on the left leg. Low-thigh circumference decreased 1.1 cm on the right leg and 1.0 on the left leg. KOOS symptoms, ADL, quality of life and FJS demonstrated a clinically relevant change on 10, 14 and 23 points.

Conclusion: The present case study indicates that even with low amounts of supervision BFR-RT could increase functional performance, reduce knee joint swelling and improve key patient-reported outcome.

The Evolution of Blood Flow Restricted Exercise

The use of blood flow restricted (BFR) exercise has become an accepted alternative approach to improve skeletal muscle mass and function and improve cardiovascular function in individuals that are not able to or do not wish to use traditional exercise protocols that rely on heavy loads and high training volumes. BFR exercise involves the reduction of blood flow to working skeletal muscle by applying a flexible cuff to the most proximal portions of a person’s arms or legs that results in decreased arterial flow to the exercising muscle and occluded venous return back to the central circulation. Safety concerns, especially related to the cardiovascular system, have not been consistently reported with a few exceptions; however, most researchers agree that BFR exercise can be a relatively safe technique for most people that are free from serious cardiovascular disease, as well as those with coronary artery disease, and also for people suffering from chronic conditions, such as multiple sclerosis, Parkinson’s, and osteoarthritis. Potential mechanisms to explain the benefits of BFR exercise are still mostly speculative and may require more invasive studies or the use of animal models to fully explore mechanisms of adaptation. The setting of absolute resistive pressures has evolved, from being based on an individual’s systolic blood pressure to a relative measure that is based on various percentages of the pressures needed to totally occlude blood flow in the exercising limb. However, since several other issues remain unresolved, such as the actual external loads used in combination with BFR, the type of cuff used to induce the blood flow restriction, and whether the restriction is continuous or intermittent, this paper will attempt to address these additional concerns.

The pathophysiological effects of exercise in the management of idiopathic inflammatory myopathies: A scoping review

Idiopathic inflammatory myopathy (IIM) is a term used for a heterogeneous group of diseases characterized by severe muscle weakness. In addition to pharmacological treatment options, non-pharmacological methods such as exercising are essential for proper management of myositis. The present article aimed to provide an insight into the potential pathophysiological mechanisms underlying exercise-related benefits in myositis. A systematic search was performed on PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar using the following keywords and their combinations: "idiopathic inflammatory myopathy", "inflammatory myopathy", "myositis", "polymyositis", "dermatomyositis", "inclusion body myositis", and "exercise". Current literature indicates that exercising has impact on both immune and non-immune pathways in patients with IIM. Exercise-related benefits include (a) increased mitochondrial biogenesis/enzyme activity, (b) reconditioning of immune/inflammatory pathways, (c) decreased endoplasmic reticulum stress, (d) modulation of gene expression, (e) increased protein synthesis and cytoskeletal remodeling, and (f) decreased muscle fibrosis and non-muscle area infiltrates. With its certain benefits, exercise stands as a precious non-pharmacological treatment option for patients with IIM.