{'fraction_non_alphanumeric': 0.022169269392791797, 'fraction_numerical': 0.008297519254499808, 'mean_word_length': 5.191253951527925, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effectiveness of Balance Exercise Program in Total Knee Arthroplasty: Meta-Analysis

Background: Balance is essential for maintaining postural stability while performing functional activities and for falls avoidance in patients with TKA.  There are very few RCTs done to assess functional improvement after TKA. Hence, this study was undertaken to find out evidence on physiotherapy treatment in TKA and analyze it.  Methods: We searched Medline, CINAHL, PEDro from the year 2001 to 2015 for RCT involving evaluations of physiotherapy exercise in adults with a knee replacement. Search criteria’s were pain, stiffness, adherence and attrition. The inclusion criteria were studies which included physiotherapy exercise for balance specific exercises which compared various functional training and functional training with balance exercise in TKA. Result: Searches identified 20 randomized trials related to TKA and physiotherapy. Only three were fulfilled the inclusion criteria. Functional training with balance exercises found to be effective in patients with total knee arthroplasty. Conclusion: After total knee replacement, interventions including physiotherapy along with balance exercises showed improvement in pain, stiffness and functional performance in mobility. 
Keywords: Osteoarthritis; Balance; Total knee arthroplasty physiotherapy.


INTRODUCTION
Knee osteoarthritis (OA) is a progressive degenerative disease and a leading cause of disability among the elderly. Prevalence of knee OA is higher among women and increases with age [1]. Patients with knee osteoarthritis experience impaired mobility and limited function in their activities of daily living because of inflammation of joint which leads to knee pain. Postural deficits and deficits in the gait pattern are evident, such as a decrease in gait velocity and stride length; in addition, patients show abnormal movement patterns when ascending and descending stairs [2]. Total knee arthroplasty (TKA) is a commonly accepted surgical procedure recommended for severe OA characterized by radiographic evidence of joint damage, moderate to severe persistent pain, and clinically significant functional limitations affecting the quality of life when conservative treatments such as nonsteroidal anti-inflammatory drugs, physical therapy, and intra-articular corticosteroid injections fail [1]. It is the most effective therapy for patients with severe knee osteoarthritis; as it relieves symptoms of knee osteoarthritis such as knee pain and stiffness.
Joint replacement (arthroplasty) is a surgical option for end stage arthritis now is advancing and millions of people across the world are benefited.  [3].
Balance is essential for maintaining postural stability while performing functional activities and for prevention of falls. Balance (dynamic and static) is a complex function which is the integration of sensory information regarding the position of the body and the ability to make appropriate motor response to body movement. It primarily depends on sensory inputs from somatosensory (proprioception), visual and vestibular systems, as well as, response of muscles. Static balance refers to maintaining equilibrium while standing in one place, whereas dynamic balance involves motion and is defined as maintaining equilibrium during locomotion. Falls and loss of balance most commonly occur during movement-related tasks such as walking and less frequently during static activities [4]. Physiological factors such as muscle weakness and impaired postural control and balance has strong association with risk of falls in older people and these may be impaired further with lower limb osteoarthritis. Falls can lead to reduced independence and function, reduced mobility, loss of confidence in mobility and reduced quality of life. For people with advanced lower limb arthritis, including those who planned for joint replacement surgery, a fall may further exacerbate mobility impairment and dependence, and possibly necessitate a delay in planned surgery, and in some cases may negatively impact on subsequent outcomes post-surgery [5]. The cost of falling is high, both to the individual (physical and psychological trauma) and the health-care system (financial burden related to surgery and rehabilitation). At the same time, costs related to the patient's inability to care for them and/or to be discharged to their home environment present additional burdens for the patient, their family, and the health-care system [6].
One most common complaint after TKA is balance impairments, which could increase fall risk in these patients. Indeed, the fall rate has been reported to be as high as 7% to 40% postoperatively. Understanding balance problems in patients after TKA is necessary [7]. However, while total knee arthroplasty (TKA) aims to relieve pain, correct deformities and restore loco-motor function, it is not with the evidences whether it has an effect on patient's balance and falls incidences. The literature suggests that patients with knee OA undergoing TKA will often present with a substantial loss of balance control and proprioceptive acuity that is frequently precipitated by a lack of confidence. Despite the high incidence of falls in this population, there are very few investigations in the literature focusing on the risk of falls and subsequent impairments in function for patients with knee OA after undergoing TKA [5].
Previous research in balance assessment for patients with TKA mainly involved advanced technology and sophisticated equipment in laboratory settings such as virtual or real obstacle avoidance, stabilogram analysis, kinematic and electromyographic analysis and computerized dynamic posturography, a Biodex Stability System which might not be available and feasible in real clinical situations. Although the Berg Balance Scale (BBS) is a common tool for balance assessment and can be considered as a reference standard for assessing balance in patients with TKA clinically. First, it mainly assesses static balance and has been shown to have considerable ceiling effects in various patient populations. Balance in important dynamic tasks, such as walking, but is not addressed in the BBS. Second, maintaining body equilibrium involves many different balance control systems. The BBS has limited ability to identify what balance systems are impaired and thus direct treatment [6].
Most patients undergo physiotherapy in the form of exercises during the first few months after surgery. Physiotherapy aims to maximize or restore physical function essential to everyday life. Physiotherapy generally focuses on strengthening exercises and functional performance-based trainings. Balance and proprioception work are usually included in training programs, but to a lesser extent. However, the recovery and enhancement of these aspects may be a determining factor, since good balance abilities positively influence the capacity to perform basic functional tasks [8]. During hospital stay, physiotherapy targets mobilization and achievement of functional goals relating to hospital discharge. Further post discharge physiotherapy and exercise best interventions promote retraining and functional improvement [9]. Although there is general agreement that exercises completed after major surgery such as TKA promote walking and independence in activities of daily living, the relative advantages of clinic-based and homebased rehabilitation programs in this population have not been documented extensively [10]. Reduction in pain and improvement in physical function and quality of life (QOL) are the main expected outcomes of pa-tients after total knee arthroplasty. Scientific and clinical evidence supports the success of TKA for the relief of knee pain and symptoms of osteoarthritis (OA), as well as a high rate of patient satisfaction. However, the functional benefits of this surgical procedure of TKA are not as convincing, because quantitative evaluations of knee function have shown that large functional impairment persist 1 year after surgery and even longer [11]. Gstoettner et al. [12] suggested that balance and proprioceptive training is effective in improving standing balance, can avoid pathological gait patterns and falls, and proposed that further investigations were needed in order to give consistency to the findings. Later, Hubber et al. [13] and Villadsenet al. [14] evaluated the effects of a preoperative neuromuscular training program. As there are few RCTs are done to assess the functional improvement after TKA, our objective will remain to find out related articles on physiotherapy treatment in TKA and analyze it.

Study design: Meta -analysis (Descriptive study)
Criteria for considering studies for this review: Studies included in this review were selected according to the following set of criteria: a) the design being a RCT; b) all patients involved had a TKA; c) all interventions in which has physiotherapy rehabilitation protocol specifically balance training also studies comparing physiotherapy with non-physiotherapeutic treatment were considered for this study d) the studies were published in peer reviewed journals from year 2010 till 2018 Search strategy for identification of studies: A search was performed using computerized bibliographic databases [Medline, CINAHL, PEDro] in the period from 2001 end 2015 to identify RCTs. This was combined with the medical subject heading TKA and other key words pertaining to TKA and physiotherapy (e.g osteoarthritis, balance, TKA, physiotherapy, randomized controlled trial).
Total27 articles were found. References of identified articles, relevant conference proceedings and textbooks were checked by the first author (CB). Any additional study that seemed eligible was retrieved and assessed according to title, abstract and keywords. The last search for RCTs was performed on June 2013.

Methodological quality assessment of the studies:
Trials included in this review were rated using a checklist called the PEDro scale (Table 1)[15]. The PEDro scale is based on the Delphi list, a validated quality assessment tool. This scale includes the following aspects of trial quality: a) the internal validity of the trial and b) whether or not the trial contains sufficient statistical information to be interpretable.
In total the PEDro scale contains 11 items, of which 10 items assess internal validity. In judging the studies, we omitted criterion one (eligibility criteria) because it refers to the generalization of the results. The maximum score by using the PEDro scale is therefore 10. Two reviewers (CB, IB), independently assessed each of the eligible studies. In case of disagreement a consensus method was used and a third reviewer (RO) was consulted to resolve this disagreement. For each study a total score ranging between 0 and 10 was calculated by summing the dichotomized scores of 2-11 of the PEDro scale.

Results of the design and the methodological quality of the studies :
The overall methodological quality of the study, assessed by using the PEDro scale, is shown in Table 3.
These studies are classified as a randomized controlled trial. The report of Sara R. Piva and Chun-De Liao showed that randomization was computer generated to assign participant in experimental and control group while randomization in study done by Pankaj Jogi is by coin toss method to assign them in typical exercise group and typical exercise plus balance exercise group.
In study A, 5 loosed in FT group while 2 loosed in FT+B group. Statistician, assessor and participants were blinded in randomization. In study B, 7 were drop out in experimental group while 10 were drop out in control group. Assessor and participants were blinded in randomization.
In study C, there were 2 dropped out in typical+ balance group while 7 were in typical group. Only participants were blinded to their group allocation. No intention to treat analysis was done for any of included study.
Results of physiotherapy as shown by the outcome measuring pain, stiffness, adherence and attrition are mentioned in study A while study B showed distance of functional forward reach; duration of single leg stance; timed sit-to-stand test; timed up-and-down stair test; timed 10m walk; timed up-and-go test; and the Western Ontario and McMaster Universities Osteoarthritis Index score. Study C measure WOMAC, Activities-specific Balance Confidence Scale, Berg Balance Scale and timed up-andgo test score. The study reported means and standard deviations, and also the standard error of the results. Besides these measures, outcomes in study B showed in descriptive tables. While in Study A and C it shows re-sult with both graphs and descriptive tables.
Characteristics of the participants: All patients in the study A had a TKA. Patients included with at least 50 years of age and had a unilateral TKA in the previous 2 to 6 months. A minimum of 2 months after TKA was specified to avoid knee pain, effusion, or limitations in motion restricting the implementation of the exercise programs.
The mean age in FT group was 67±6 year and in FT+B group a range was given from 70±10 years.
While in study B, patients aged 50-85 years who were scheduled to undergo unilateral total knee replacement were potential candidates for this study.
In study C patients who had primary unilateral THA or TKA as a result of hip or knee joint OA and had been advised by their surgeon to weight-bear as tolerated following their surgery were included.
Home Exercise Program: The home exercise program was same as the supervised exercise program, with some modifications for the home exercises such as For the FT program: Stationary cycling or treadmill walking was replaced by walking outside.

Effects of the interventions:
Both the study shows improvement in patient's condition post-operatively RCT, randomly assigned into Typical exercise group (n= 33) and Typical exercise + balance group (n=30). Only participants were blinded for treatment.
Inclusion criteria: Who had primary unilateral THA or TKA because of hip or knee joint OA and had been advised by their surgeon to weight-bear as tolerated following their surgery. Exclusion criteria: Patients with revision THA or TKA, or those who had been advised by their surgeon to remain nonweightbearing or partial weight-bearing on either the operated or nonoperated leg and patients with neurological condition.
In the 5 week protocol participants in the TE group completed joint ROM and muscle strengthening exercises, and those in the TE + B group completed joint ROM, muscle strengthening, and additional balance exercises with 410 repetitions thrice a day.
Outcomes assessed prior to the intervention and after 5 week of exercise training. Outcomes used were the Berg Balance Scale, Timed Up and Go test, the Western Ontario McMaster Universities Osteoarthritis Index, and the Activities-specific Balance Confidence Scale with balance training program. In study A, degree of improvement seemed higher for gait speed, single-leg stance time, and stiffness in the FT+B group compared with the FT group. In study B, it demonstrated significant changes in 10-m walk and in timed up-and-go tests along with significant changes of all other measures and WOMAC index. Study C showed significantly greater improvements in balance and functional mobility compared to typical exercises alone in the typical plus balance exercise.

RESULTS
Included studies review progress was summarized as a flow diagram in Figure 1. Twenty seven eligible randomized controlled trials were identified. 24 were excluded. Characteristics of the 3 included studies are presented in Table 1. Studies ranged in size from 43-160 patients (median 94) and included a total of 1,739 patients. Where reported, the main diagnosis was osteoarthritis, and the mean age in studies ranged from 66 to 73.5 years. The duration of follow up ranged from 3 weeks to 24 months, though we describe data in our meta-analysis from 3 months onwards.
One RCT involving patients with TKA and physiotherapy were identified (A. Sara R. Piva Table 2 for characteristics of these studies.

DISCUSSION
Randomized controlled trials of physiotherapy and exercise interventions after TKA provide some evidence forshort term effectiveness. Three randomized controlled trials were identified over the time period from 2010 to 2018, these trials (Sara R. Piva,et al.Chun-De Liao, et al and Pankaj Jogi, et al.) showing diversity in many aspects: heterogeneous patient groups, interventions and outcome measures. The quality of the studies was reasonable/good. While studying exercise therapy approaches, it is important to consider factors that may contribute to functional deficits of patients with TKA. One such important factor may be impaired movement control and balance. Although during TKA surgery several tendons, capsule, and remaining ligaments are retightened to restore the joint spaces deteriorated by the arthritis, to restore the intra-articular geometry, some of the knee ligaments are removed or released. These alterations may affect the function of several mechanoreceptors and impaired movement control and balance. Several studies have identified deficits in components of the balance system, such as decreased ability to detect joint position and motion, delayed muscle latency, altered amplitude of muscle activity, and decreased postural control, in patients after TKA. Therefore, exercises aimed at improving the impaired movement control and balance of patients after TKA should be considered [16].   Progress from 10 to 20 repetitions. Progress cuff weights as tolerated.

Get up from a chair and sit back down
Patient is sitting in a chair with both feet flat on the floor and the hips flexed to 90 degrees. Patient stands up and then sits back in the chair (2 seconds to stand and 3 seconds to sit down). Patient initially uses chair armrests for assistance Progress from 10 to 20 repetitions. Progress by not using armrest.

Bilateral knee flexion/ extension in standing position
Patient is standing with feet together and hands holding on to a handrail. Patient slowly squats down until the knees bend 90 degrees and then slowly returns to a standing position. Patient starts exercise while bearing moderate body weight on handrail.
Progress from 10 to 20 repetitions. Progress by only touching handrail for balance. Unilateral knee flexion/ extension in standing position Patient is standing over one foot and hands holding on to a handrail. Patient will slowly squat down until the knee bends 90 degrees and then slowly return to a standing position. Patient starts exercise while bearing moderate body weight on handrail.
Ascend and descend stairs Patient climbs up and down a flight of stairs.
Progress from 10 to 30 steps. Speed as tolerated.
Stationary cycling or treadmill walking Patient selects stationary bicycle or treadmill walking. Activity is performed from 50% to 75% of the patient's predicted heart rate. If patient has no preference, treadmill walking is the exercise of choice. For stationary bicycle, the seat height is adjusted so that the knee can fully extend on the down stroke of cycling.
Progress from 5 to 20 minutes. Speed as tolerated.

Roller board and platform perturbations
Patient stands with one limb on a stationary platform and the other leg on a roller board. Therapist perturbs roller board in multiple directions, at random, and the patient attempts to resist the perturbations. One bout of 30 seconds. May begin with patient in a semi-seated position, with hips resting on plinth.
Activity progresses to full standing position.
posture and motor learning and relearning. Joint motion and position sense also have an equally important role in the maintenance of balance. Diminished joint sensations is observed as a factor contributing to balance deficits in the elderly and patients with osteoarthritis of the knee present with worse balance than that demonstrated by age-matched controls [8].
Despite the fact that many patients with TKA are referred for physiotherapy, little is known about the evidence of the balance exercise program of physiotherapy.
Reasons for the small number of RCTs could be that the percentage of physiotherapists treating patients with TKA is small, or that specialists are not well informed about the treatment possibilities of physiotherapy. Another reason could be that it is difficult to generate groups with enough numbers of homogenous patients which matches at their baseline characteristics. The high requirements of RCT guidelines such as described in the CONSORT statement (Consolidated Standards of Reporting Trials) finds difficult to physiotherapists in performing a RCT.
Improvements in balance as observed in this study are supported by previous studies following balance intervention in patients with other health conditions. Diracoglu et al. in an 8-week study showed improvement in balance from kinesthesia and balance exercises added to strengthening exercises as compared to strengthening exercises alone in female patients with knee OA [17]. Williams et al. also reported improvement in balance following a home-based balance exercise program in women with lower limb OA or rheumatoid arthritis on balance measures such as functional reach test, but no increase in the WOMAC function scores was observed [18]. Hiroyuki reported significant improvement in balance measures such as one leg stand test, functional reach test, and the TUG following balance and gait exercise in the frail elderly population [19].
Assessment of proprioception is important for identifying proprioceptive deficits so as to avoid falls. There is a substantial amount of evidence that shows the importance of proprioception for production of smooth, controlled and coordinated movements, maintenance of    With three RCT we were unable to perform a metaanalysis. Applying the PEDro scale also gave considerations/objections, a disadvantage of the scale being the extended blinding. In physiotherapeutic research it is often not possible to blind both patients and therapists for a specific intervention, giving a substantially lower score on the PEDro scale.
A further disadvantage is that the number of patients is not categorized in the PEDro scale. The number of participants ranged from 40 to 50; without using a power calculation to detect the number of patients needed in the trial. An incorrect number of patients can give false results.
There are insufficient studies with adequate patient numbers to provide conclusive evidence on different methods of provision.
There is increased number of TKA observed in the age group between 50 to 70 years. To regain balance in patients with TKA take a long duration. The outcome used in this study is balance specific along with functional specific. For the future it is important that well-designed randomized controlled trials are conducted in order to validate physiotherapy protocol for patients with TKA.

CONCLUSION
After total knee replacement, physiotherapy interventions including balance specific exercises show improvements in pain, stiffness and functional performance in mobility after surgery. Further randomized controlled studies are required to determine the effectiveness of balance exercises in patients with TKA.
Limitations: There are limited RCT's available for functional improvement after TKA. Full text paid articles were not assessed due to lack of free accessibility.