The Role of Bracing

Fundamentals of osteoarthritis. Rehabilitation: Exercise, diet, biomechanics, and physical therapist-delivered interventions

Insights related to the pathogenesis of osteoarthritis (OA) have informed rehabilitative treatments that aim to mitigate the influence of several known impairments and risk factors for OA, with the goal to improve pain, function, and quality of life. The purpose of this invited narrative review is to provide fundamental knowledge to non-specialists about exercise and education, diet, biomechanical interventions, and other physical therapist-delivered treatments. In addition to summarizing the rationale for common rehabilitative therapies, we provide a synthesis of current core recommendations. Robust evidence based on randomized clinical trials supports exercise with education and diet as core treatments for OA. Structured, supervised exercise therapy is advised. The mode of exercise may vary but should be individualized. The dose should be based on an initial assessment, the desired physiological changes, and progressed when appropriate. Diet combined with exercise is strongly recommended and studies demonstrate a dose-response relationship between the magnitude of weight loss and symptom improvement. Recent evidence suggests the use of technology to remotely deliver exercise, diet and education interventions is cost-effective. Although several studies support the mechanisms for biomechanical interventions (e.g., bracing, shoe inserts) and physical therapist-delivered (passive) treatments (e.g., manual therapy, electrotherapeutic modalities) fewer rigorous randomized trials support their clinical use; these therapies are sometimes recommended as adjuncts to core treatments. The mechanisms of action for all rehabilitative interventions include contextual factors such as attention and placebo effects. These effects can challenge our interpretation of treatment efficacy from clinical trials, yet also provide opportunities to maximize patient outcomes in clinical practice. When evaluating rehabilitative interventions, the field may benefit from increased emphasis on research that considers contextual factors while evaluating mechanistic, longer-term, clinically-important and policy-relevant outcome measures.

Biomechanical Effect of Valgus Knee Braces on the Treatment of Medial Gonarthrosis: A Systematic Review

Background

Valgus braces are prescribed as a common conservative treatment option for patients with medial gonarthrosis to improve their quality of life. Many studies had reviewed the effects of the valgus braces on patients with medial gonarthrosis, while they mainly focused on the knee adduction moment (KAM), with less attention paid to other parameters such as spatiotemporal and morphological parameters.

Objectives

The purpose of this study was to review the effects of valgus braces on the spatiotemporal, kinematic/kinetic, morphological, and muscle parameters.

Methods

Based on the selected keywords, a survey of literatures was performed in Web of Science, PubMed, Scopus, and Google Scholar using the PRISMA methods, and the search period was established from January 2000 to March 2022.

Results

Thirty-four articles were included. According to the conclusion of these articles, the valgus brace can be used to relieve the symptoms of patients with medial gonarthrosis by decreasing the varus angle, decreasing the KAM, and redistributing the knee compartment loads. However, the effects of valgus braces on other biomechanical parameters (e.g., walking speed, cadence, joint angle, and joint space) had not reached a consensus.

Conclusions

The valgus knee brace can effectively relieve the symptoms of medial gonarthrosis through multiple mechanisms, while there is still some confusion about the effectiveness of the valgus brace on the other biomechanical parameters.

Evaluation of a lower-extremity robotic exoskeleton for people with knee osteoarthritis

A multi-site study was conducted to evaluate the efficacy of the Keeogo™ exoskeleton as a mobility assist device for use in the clinic and at home in people with knee osteoarthritis (KOA). Twenty-four participants were randomized in a two-stage cross-over design that evaluated the immediate effects of using the exoskeleton in the clinic and the cumulative effects of training and home use. Immediate effects were quantified by comparing 1) physical performance with|without (W|WO) the device during a battery of mobility tests, and 2) physical activity levels at home (actigraphy) for one month, two weeks W|WO the device. Cumulative effects were quantified as change in physical performance W and WO over time. WOMAC and other self-report scales were measured and usability assessed. There were no immediate effects on physical performance or physical activity at home; however, there were cumulative effects as indicated by improved stair time (p = .001) as well as improved WOMAC pain (p = .004) and function (p = .003). There was a direct relationship between improved physical function and improved WOMAC pain (r = -.677, p < .001) and stiffness (r = .537, p = .007). Weight and battery life were identified as important to usability. A full-scale RCT with more participants, longer study period, and better usage monitoring is warranted.

Biomechanical Study of a Tricompartmental Unloader Brace for Patellofemoral or Multicompartment Knee Osteoarthritis

Objective: Off-loader knee braces have traditionally focused on redistributing loads away from either the medial or lateral tibiofemoral (TF) compartments. In this article, we study the potential of a novel "tricompartment unloader" (TCU) knee brace intended to simultaneously unload both the patellofemoral (PF) and TF joints during knee flexion. Three different models of the TCU brace are evaluated for their potential to unload the knee joint. Methods: A sagittal plane model of the knee was used to compute PF and TF contact forces, patellar and quadriceps tendon forces, and forces in the anterior and posterior cruciate ligaments during a deep knee bend (DKB) test using motion analysis data from eight participants. Forces were computed for the observed (no brace) and simulated braced conditions. A sensitivity and validity analysis was conducted to determine the valid output range for the model, and Statistical Parameter Mapping was used to quantify the effectual region of the different TCU brace models. Results: PF and TF joint force calculations were valid between ~0 and 100 degrees of flexion. All three simulated brace models significantly (p < 0.001) reduced predicted knee joint loads (by 30-50%) across all structures, at knee flexion angles >~30 degrees during DKB. Conclusions: The TCU brace is predicted to reduce PF and TF knee joint contact loads during weight-bearing activity requiring knee flexion angles between 30 and 100 degrees; this effect may be clinically beneficial for pain reduction or rehabilitation from common knee injuries or joint disorders. Future work is needed to assess the range of possible clinical and prophylactic benefits of the TCU brace.

Unloader knee brace increases medial compartment joint space during gait in knee osteoarthritis patients

PURPOSE

The purpose of the present study was to investigate the effect of the unloader brace on medial compartment dynamic joint space (DJS) during gait, while simultaneously recording ground reaction force (GRF) in varus knee osteoarthritis (OA) patients using a highly accurate biplane radiography system which allowed continuous measurement of DJS from heel strike through the midstance phase of gait. The hypothesis was that DJS in the medial compartment would be greater with the unloader brace than without the brace during gait.

METHODS

After 2 weeks of daily use of the unloader brace, ten varus knee OA patients (age 52 ± 8 years) walked with and without the brace on an instrumented treadmill, while biplane radiographs of the OA knees were acquired at 100 Hz. Medial compartment DJS was determined from heel strike to terminal stance (0-40% of the gait cycle) using a validated volumetric model-based tracking process that matches subject-specific 3D bone models to the biplane radiographs. The GRF during gait was collected at 1000 Hz. Repeated-measures ANOVA was used to explore differences in medial compartment DJS and GRF between the unbraced and braced conditions. A patient-reported subjective questionnaire related to the brace use was collected at the time of the test.

RESULTS

Medial compartment DJS was significantly greater with the unloader brace than without the brace during gait (P = 0.005). The average difference was 0.3 mm (95% confidence interval 0.1-0.4 mm). No significant difference was observed in terms of vertical GRF between the two conditions. The questionnaire showed participants felt reduced pain when wearing the brace.

CONCLUSION

The unloader brace has the significant effect of increasing medial compartment DJS during gait, which supports the underlying premise that the unloader brace reduces pain by increasing medial joint space during dynamic loading activities.

LEVEL OF EVIDENCE

III.

Comparison of the effect of Western-made unloading knee brace with physical therapy in Asian patients with medial compartment knee osteoarthritis-A preliminary report

PURPOSE

To compare the effect of unloading knee brace with physical therapy (PT) in Asian patients with osteoarthritis (OA) of the knee.

METHOD

This is a non-random, two-group comparative study. Patients with medial compartment knee OA (n = 41) were assigned to either the brace group (n = 20) or PT group (n = 21). Patients in the brace group were fitted with an unloading knee brace for three months and the PT group received a 60-min session of physiotherapy over the affected knee, three times a week, for three months. The primary outcome measures were the pain visual analogue scale (VAS) and the Western Ontario McMaster University Osteoarthritis Index (WOMAC); the second outcome measures were the 36-item Short-Form Health Survey (SF-36) and patient's satisfaction. The patients were evaluated at baseline, and at one month and three months.

RESULTS

Group comparison showed no significant difference regarding pain VAS, WOMAC, SF-36, and patient's satisfaction, except stiffness in WOMAC (P = .006) and social functioning in SF-36 (P = .007). Time and group interaction revealed significant differences only in general health (P = .007) and mental health (P = .006) of SF-36. Within-group comparison found that pain VAS and WOMAC decreased significantly at one months and three months in both groups.

CONCLUSION

The effect of brace fitting in patients with knee OA was similar to that of physical therapy. A Western-made unloading knee brace is acceptable in some Asian people with knee OA.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02712710.

Methods for evaluating effects of unloader knee braces on joint health: a review

The paper aims to provide a state-of-the-art review of methods for evaluating the effectiveness and effect of unloader knee braces on the knee joint and discuss their limitations and future directions. Unloader braces are prescribed as a non-pharmacological conservative treatment option for patients with medial knee osteoarthritis to provide relief in terms of pain reduction, returning to regular physical activities, and enhancing the quality of life. Methods used to evaluate and monitor the effectiveness of these devices on patients' health are categorized into three broad categories (perception-, biochemical-, and morphology-based), depending upon the process and tools used. The main focus of these methods is on the short-term clinical outcome (pain or unloading efficiency). There is a significant technical, research, and clinical literature gap in understanding the short- and long-term consequences of these braces on the tissues in the knee joint, including the cartilage and ligaments. Future research directions may complement existing methods with advanced quantitative imaging (morphological, biochemical, and molecular) and numerical simulation are discussed as they offer potential in assessing long-term and post-bracing effects on the knee joint.

Validation of method for analysing mechanics of unloader brace for medial knee osteoarthritis

Unloader braces are one non-invasive treatment of knee osteoarthritis, which primarily function by applying an external abduction moment to the joint to reduce loads in the medial compartment of the knee. We developed a novel method using brace deflection to estimate the mechanical effect of valgus braces and validated this model using strain gauge instrumentation. Three subjects performed static and walking trials, in which the moment applied by an instrumented brace was calculated using the deflection and strain methods. The deflection method predicted average brace moments of 8.7 Nm across static trials; mean error between the deflection model predictions and the gold-standard strain gauge measurements was 0.32 Nm. Mean brace moment predictions throughout gait ranged from 7.1 to 8.7 Nm using the deflection model. Maximum differences (MAE) over the gait cycle in mean and peak brace moments between methods were 1.50 Nm (0.96) and 0.60 Nm (0.42). Our proposed method enables quantification of brace abduction moments without the use of custom instrumentation. While the deflection-based method is similar to that implemented by Schmalz et al. (2010), the proposed method isolates abduction deflection from the 3 DOF angular changes that occur within the brace. Though the model should be viewed with more caution during swing (MAE = 1.16 Nm), it was shown that the accuracy is influenced by the uncertainty in angle measurement due to cluster spacing. In conclusion, the results demonstrate that the deflection-based method developed can predict comparable brace moments to those of the previously established strain method.

Neurological patients and their lower limb orthotics: An observational pilot study about acceptance and satisfaction

BACKGROUND

Although an orthotic device of the lower limb improves the functionality of neurological patients, anecdotally clinical experience suggests that the compliance is rather limited.

OBJECTIVES

The aim was to determine the satisfaction and acceptance of a lower limb orthotic device.

STUDY DESIGN

A qualitative observational pilot study with a mix-method design.

METHODS

Adult neurological patients who had a prescribed lower limb orthotic device were included. One published and clinically used questionnaire about satisfaction (D-Quest) and one ad hoc constructed questionnaire about acceptance of the orthotic device (MIRAD-ACCORT questionnaire) were used for data collection.

RESULTS

In total, 33 patients participated (28 ankle-foot orthotic device, 3 knee-ankle-foot orthotic device and 2 other types). In general, they were satisfied about their orthotic device and the services. Less than one-fourth of the patients had some negative comments about the 'visual aspects' and the 'ability to hide' of their orthotic device. These, however, had a lower priority when compared with functionality, which was reported as a main advantage and is a reason for continuing the use of their orthotic device.

CONCLUSION

Patients were satisfied in relation to their lower limb orthotic device. With regard to acceptance, it can be concluded that factors associated with functionality and comfort are more important than the aesthetic and psychological aspects of the orthotic device. Clinical relevance Patients were satisfied with their lower limb orthotic device. Some patients had some negative comments about the 'aesthetics aspects' and the 'ability to hide' their orthotic device. However, improvements in functionality were mostly reported as a main advantage and a reason for continuing the use of their orthotic device.

Knee Osteoarthritis: Does Transcutaneous Electrical Nerve Stimulation Work?

Transcutaneous electrical nerve stimulation has been proposed as a nonoperative treatment for osteoarthritis. The purpose of this study was to evaluate the outcomes of a novel transcutaneous electrical nerve stimulation device compared with those of other standard nonoperative modalities for the treatment of osteoarthritis of the knee.

Current state of unloading braces for knee osteoarthritis

PURPOSE

Unicompartmental knee osteoarthritis (OA) is often treated with the prescription of an unloading knee brace to decrease pain and stiffness. Braces have been shown to improve the quality of life by applying an external moment to offset increased compressive tibiofemoral contact loads, but evidence regarding mechanical efficacy at the joint is controversial. Thus, the purpose of this study was to review the current state of unloading braces on knee mechanics, clinical impact, and long-term disease progression.

METHODS

A literature search was performed through the PubMed MEDLINE database for the search terms "osteoarthritis," "knee," "brace," and derivatives of the keyword "unload." Articles published since January 1, 1980 were reviewed for their relevance. Evidence for the effectiveness of unloading braces for disease management both biomechanically and clinically was considered.

RESULTS

While significant research has been done to show improvement in OA symptoms with the use of an unloading brace, current literature suggests a debate regarding the effectiveness of these braces for biomechanical change. Clinical findings reveal overall improvements in parameters such as pain, instability, and quality of life.

CONCLUSION

Although clinical evidence supports brace use to improve pain and functional ability, current biomechanical evidence suggests that unloading of the affected knee compartment does not significantly hinder disease progression.

LEVEL OF EVIDENCE

III.

The current role of orthoses in treating haemophilic arthropathy

INTRODUCTION

Haemophilic arthropathy (HA) is an inevitable consequence of repeated haemarthroses in people with haemophilia, and principally affects their ankles, knees and elbows. It is advisable that haematological treatment be complemented with rehabilitation therapy and surgery. Orthoses are devices that are used within the framework of rehabilitation, in order to change the functional or structural characteristics of the neuromusculoskeletal system.

MATERIALS AND METHODS

This article reviews the design, the materials and characteristics of orthoses and the indications for the various orthoses used in HA. Ankle, knee, elbow orthoses, insoles, footwear modifications and orthopedic shoes are discussed.

RESULTS

Orthoses can control or prevent joint movement, stabilise a specific joint or relieve the load or stress on it. These devices must be prescribed by a physician within the framework of rehabilitation. Recommendations for the proper selection and use of orthoses are highly complex.

DISCUSSION

To maximise the benefits of this mode of therapy, a profound understanding of anatomy and biomechanics is crucial, as is an understanding of the devices available for the various joints that may be affected by HA (ankles-feet, knees, elbows).

CONCLUSIONS

Orthotic devices can reduce pain and improve quality of life of people with HA, delaying surgery in many cases.

Does knee malalignment predict the efficacy of realignment therapy for patients with knee osteoarthritis?

BACKGROUND

Realignment therapies, including knee braces, foot orthoses and shoes are prescribed to patients with medial knee osteoarthritis (OA) with the goal of unloading the medial tibiofemoral (TF) compartment. It is uncertain whether realignment therapies have different effects in those with knee malalignment. We studied whether the efficacy of realignment therapy for pain and function in persons with medial TF OA is predicted by the severity of the baseline knee malalignment.

METHODS

The baseline characteristics of 48 participants with moderate to severe medial knee OA were collected. Participants' pain and function were measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale before and after 12 weeks of realignment therapy using a valgus unloader knee brace plus bilateral neutral foot orthoses and motion control shoes. Anatomical axis (AA) was measured on weight-bearing knee radiographs by a blinded reader and knee malalignment was categorized as either varus malaligned (moderate or severe) or neutral according to the AA angle. We assessed for differences in response to treatment according to alignment category. General linear statistical models were generated to determine which of the measured alignment variables and covariates predicted change in the pain outcome.

RESULTS

Anatomical axis knee alignment was not a significant predictor of pain or function change with active treatment. Baseline WOMAC scores were the best predictor of change in WOMAC (P < 0.01 and P = 0.06 for pain and function, respectively).

CONCLUSIONS

Baseline knee alignment did not predict the efficacy of 12 weeks realignment therapy in participants with medial tibiofemoral OA. [Correction added on 27 August 2015, after first online publication: 'did predict' has been corrected to 'did not predict' in the conclusions of the abstract section.].

Strength and Functional Improvement Using Pneumatic Brace with Extension Assist for End-Stage Knee Osteoarthritis: A Prospective, Randomized trial

Pneumatic unloader bracing with extension assists have been proposed as a non-operative modality that may delay the need for knee surgery by reducing pain and improving function. This prospective, randomized trial evaluated 52 patients who had knee osteoarthritis for changes in: (1) muscle strength; (2) objective functional improvements; (3); subjective functional improvements; (4) pain; (5) quality of life; and (6) conversion to total knee arthroplasty (TKA) compared to standard of care. Patient outcomes were evaluated at a minimum 3 months. Braced patient's demonstrated significant improvements in muscle strength, several functional tests, and patient reported outcomes when compared to the matched cohort. These results are encouraging and suggest that this device may represent a promising alternative to standard treatment methods for knee osteoarthritis.

Biomechanical effects of valgus knee bracing: a systematic review and meta-analysis

To review and synthesize the biomechanical effects of valgus knee bracing for patients with medial knee osteoarthritis (OA). Electronic databases were searched from their inception to May 2014. Two reviewers independently determined study eligibility, rated study quality and extracted data. Where possible, data were combined into meta-analyses and pooled estimates with 95% confidence intervals (CI) for standardized mean differences (SMD) were calculated. Thirty studies were included with 478 subjects tested while using a valgus knee brace. Various biomechanical methods suggested valgus braces can decrease direct measures of medial knee compressive force, indirect measures representing the mediolateral distribution of load across the knee, quadriceps/hamstring and quadriceps/gastrocnemius co-contraction ratios, and increase medial joint space during gait. Meta-analysis from 17 studies suggested a statistically significant decrease in the external knee adduction moment (KAM) during walking, with a moderate-to-high effect size (SMD = 0.61; 95% CI: 0.39, 0.83; P < 0.001). Meta-regression identified a near-significant association for the KAM effect size and duration of brace use only (β, -0.01; 95% CI: -0.03, 0.0001; P = 0.06); with longer durations of brace use associated with smaller treatment effects. Minor complications were commonly reported during brace use and included slipping, discomfort and poor fit, blisters and skin irritation. Systematic review and meta-analysis suggests valgus knee braces can alter knee joint loads through a combination of mechanisms, with moderate-to-high effect sizes in biomechanical outcomes.

Managing the pain of knee osteoarthritis

Pain from knee osteoarthritis creates a significant burden for symptomatic patients, who are often forced to change their lifestyle because of their symptoms. Activity modification, therapy, weight loss, nonsteroidal anti-inflammatory drugs, shoe orthotics, bracing, and injections are the nonoperative options available. New technologies are also emerging in the treatment of knee osteoarthritis. Ultimately, these therapeutic modalities should reduce pain and increase the overall functioning of patients. These nonoperative modalities give the clinician several effective options before surgical management is considered.

Differences in proprioception, muscle force control and comfort between conventional and new-generation knee and ankle orthoses

The aim of this study was to compare muscle force control and proprioception between conventional and new-generation experimental orthoses. Sixteen healthy subjects participated in a single-blind controlled trial in which two different types of orthosis were applied to the dominant knee or ankle, while the following variables were evaluated: muscle force control (accuracy), joint position sense, kinesthesia, static balance as well as subjective outcomes. The use of experimental orthoses resulted in better force accuracy during isometric knee extensions compared to conventional orthoses (P=0.005). Moreover, the use of experimental orthoses resulted in better force accuracy during concentric (P=0.010) and eccentric (P=0.014) ankle plantar flexions and better knee joint kinesthesia in the flexed position (P=0.004) compared to conventional orthoses. Subjective comfort (P<0.001) and preference scores were higher with experimental orthoses compared to conventional ones. In conclusion, orthosis type affected static and dynamic muscle force control, kinesthesia, and perceived comfort in healthy subjects. New-generation experimental knee and ankle orthoses may thus be recommended for prophylactic joint bracing during physical activity and to improve the compliance for orthosis use, particularly in patients who require long-term bracing.