Relevance of orthostatic posturography for clinical evaluation of hip and knee joint arthroplasty patients

Postural stability computerized evaluation in total knee arthroplasty

PURPOSE

To evaluate the balance in patients with total knee arthroplasty (TKA) and knee osteoarthrosis (KOA), measured by postural stability computerized evaluation (PSCE), and to evaluate the effect of post-TKA patients' characteristics in their performance on PSCE.

MATERIALS AND METHODS

An observational cross-sectional study was conducted in two sets of patients: (A) patients with KOA and primary TKA surgery scheduled and (B) patients who underwent primary TKA >9 months. Sociodemographic, radiographic, clinical and PSCE parameters (using the Biodex Balance System) were assessed.

RESULTS

Post-TKA patients placed more load on the replaced knee than the contralateral osteoarthritic knee (p = 0.027). They had less imbalance on the balance tests performed with the eyes open, on stable (p = 0.032), and unstable platforms (p = 0.022). These patients also showed better postural stability in monopodalic stance, both standing on the TKA (p = 0.010) and contralateral knee (p = 0.017). Age, weight, pain on the operated knee, extension deficit on the operated knee, and Berg Balance Scale scores on post-TKA patients were significantly associated with their performance on PSCE tests.

CONCLUSIONS

PSCE can be useful to quantify the balance of post-TKA and KOA patients.

Balance and proprioception impairment, assessment tools, and rehabilitation training in patients with total hip arthroplasty: a systematic review

BACKGROUND

Osteoarthritis and subsequent total hip arthroplasty (THA) lead to damages to hip joint mechanoceptors, which in turns lead to impairments in proprioception. One of the abilities mainly affected by an altered joint proprioception is balance. The aim of this work was to investigate the balance and proprioception impairments, current assessment tools, and rehabilitation training after THA.

METHODS

A systematic literature revision was conducted on PubMed, Web of Science and Cochrane databases. Articles reporting balance and proprioception impairments, current assessment tools, or rehabilitation interventions were included. Methodological quality was assessed using the Downs and Black checklist. A total of 41 articles were included, 33 discussing balance and proprioception assessment, and 8 dealing with training. Data related to type of surgical approach, type and timing of assessment protocols, assessment instrumentation, and type, volume and duration of the rehabilitation training were extracted from each study.

RESULTS

Thirty-one studies were of high quality, 2 of moderate quality and 8 of low-quality. Literature review showed an improvement in balance following THA in comparison with the pre-operative performance, although balance abnormalities persist up to 5 years after surgery, with THA patients showing an increased risk for falls. Balance training is effective in all the rehabilitation phases if specifically structured for balance enhancement and consistent in training volume. It remains unclear which assessments are more appropriate for the different rehabilitation phases, and if differences exist between the different surgical procedures used for THA. Only two studies assessed proprioception.

CONCLUSION

Balance and proprioception show impairments up to 5 years after THA, increasing the risk of falls. However, patients with THA may benefit of an adequate balance training. Further research is needed to investigate the gaps in balance and proprioception assessment and training following THA surgery.

Effects of total knee arthroplasty for primary knee osteoarthritis on postural balance: A systematic review

BACKGROUND

Knee osteoarthritis is often related to physical function impairment. Although total knee arthroplasty is considered effective for advanced cases of knee osteoarthritis, its effects on postural balance is a topic of debate.

RESEARCH QUESTION

What are the effects of total knee arthroplasty for primary knee osteoarthritis on postural balance compared to preoperative status and/or to healthy controls?.

METHODS

Longitudinal studies (with more than 1-month follow-up) assessing postural balance measures (either clinical-based such as balance scales or laboratory-based such as postural sway) were considered eligible and selected in a 2-phase process. Six main electronic databases were searched, complemented by 3 grey literature sources. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tools.

RESULTS

A total of 19 studies were included for qualitative synthesis, of which 14 had low and 5 had a moderate risk of bias. The follow-up period ranged from 1-24 months. Most studies (n = 11) presented comparisons to preoperative status only. From these, 7 studies reported relevant improvements in postural balance, 2 reported partial improvements, and 2 no improvements. The remaining studies (n = 8) presented comparisons to healthy controls and, although improvements following total knee arthroplasty were consistently observed, only one study reported postural balance measures comparable to that of controls.

CONCLUSIONS

The majority of studies reported relevant improvements (especially in clinical-based measures) compared to preoperative evaluations, although inconsistencies were found possibly due to variability in studies' populations, assessment tools, and follow-up times. Despite this, persistent deficits in postural balance were commonly observed when compared to healthy controls.

SIGNIFICANCE

This evidence synthesis could better inform clinicians and researchers about the therapeutic effects and limitations of total knee arthroplasty concerning postural balance. Standardization of assessment tools is recommended to strengthen the certainty of cumulative evidence.

Instrumented platforms for balance and proprioceptive assessment in patients with total knee replacement: A systematic review and meta-analysis

BACKGROUND

The functional outcome of total knee replacement (TKR) is usually satisfying. However, patients may show functional limitations for years after surgery, which have been ascribed to impairments in balance and proprioception, mainly during standing tasks. A number of instrumentations and parameters have been used, rising confusion for clinical decisions on the assessment of patients.

RESEARCH QUESTION

Which are the most widespread and consistent procedures to assess balance and proprioception following TKR?

METHODS

A literature review was conducted in Pubmed, PEDro, and Cochrane database. From a total sample of 112 articles, 23 original studies published between 2008 and 2019 met inclusion criteria. The primary outcomes selected were variables related to balance and proprioception assessment in static and dynamic tasks performed with instrumented platforms. Data from papers using the same instrumentation, on patients with unilateral TKA and at least 12 months postoperatively were synthesized quantitatively in a random effect meta-analysis.

RESULTS

Fourteen articles were appropriate for the review. A large variability was found both in the instrumentation and the parameters used. The Neurocom Balance Master System™ was the most used instrument (four articles). On a total population of 186 patients with unilateral TKR 12 months postoperatively, a low degree of heterogeneity was found adopting the random effect in the four tasks explored (Firm and Foam Surface both with Eyes Open and Eyes Closed).

SIGNIFICANCE

This review found a large variability in the instrumentation used to assess balance and proprioception in patients operated on TKR. The meta-analysis demonstrated that the Neurocom Balance Master System™ for static assessment of balance showed an acceptable consistency and can be considered as a reference for further studies. However, balance and proprioception impairments following TKR have not been widely quantified by means of instrumented platforms. Further research is needed to address this issue, and improve clinical practice.

Postural Stability and Dynamic Balance in Adult Spinal Deformity: Prospective Pilot Study

OBJECTIVE

We sought to evaluate dynamic balance and postural stability in patients with adult spinal deformity (ASD) compared with published age-matched normative data.

METHODS

Eleven patients with ASD were prospectively enrolled. Postural stability was tested using static and dynamic posturography; patients stood on a movable platform with an integrated force plate and performed standardized sensory organization testing (SOT), evaluating the influence of sensory processing on postural stability under 6 conditions, and motor control testing, assessing reflexive postural reactions to an external perturbation. Patient performance was compared with that of published age-matched controls. Quality of life metrics included scores on the Scoliosis Research Society-22 questionnaire, SF-36, and Morse Fall Scale. Correlations between postural stability and radiographic measurements were performed.

RESULTS

ASD patients demonstrated significantly lower SOT scores (P ≤ 0.03) in 5 of 6 conditions tested and greater latency of limb movement during backward translation (P = 0.04) compared with controls. Lower SOT scores were associated with a history of falls. ASD patients who self-reported falling in the previous 6 months, when compared with nonfallers, demonstrated significantly lower SOT scores (P = 0.04) and significantly lower Scoliosis Research Society-22 self-image subscores (P = 0.003). Thoracic kyphosis and mediolateral sway (predictor of falls) were positively correlated in the eyes-open and eyes-closed conditions (P ≤ 0.04).

CONCLUSIONS

ASD patients demonstrated impaired postural stability, diminished sensory integration, and delayed response to external perturbations compared with normal control data. Postural stability and quality of life metrics correlated with self-reported falls. These findings suggest that ASD patients have abnormal postural stability and may be at elevated risk of falls.

Electromyographic study of hip muscles involved in total hip arthroplasty: Surprising results using the direct anterior minimally invasive approach

BACKGROUND

The functional and clinical benefit of minimally invasive total hip arthroplasty (THA) is well-known, but the literature reports impaired gait and posture parameters as compared to the general population, especially following use of the anterior minimally invasive approach, which has more severe impact on posture than the posterior approach. The reasons for this impairment, however, remain unexplained. We therefore conducted a surface electromyography (sEMG) study of the hip muscles liable to be affected by arthroplasty surgery: gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S). The study addressed the following questions: (1) Is bipodal and unipodal GMed activity greater following anterior THA than in asymptomatic subjects? (2) Is a single manual test sufficient to assess maximal voluntary contraction (MVC) in hip abductors (GMax, GMed, TFL) and flexors (TFL, S)?

HYPOTHESIS

Bipodal and unipodal GMed activity is greater following anterior THA than in asymptomatic subjects.

METHOD

Eleven patients with anterior THA and 11 asymptomatic subjects, matched for age, gender and body-mass index, were included. Subjects underwent 3 postural tests: bipodal, eyes closed (BEC), unipodal on the operated side (UOP), and unipodal on the non-operated side (UnOP), with unipodal results averaged between both sides in the asymptomatic subjects. Data were recorded from 4-channel EMG and a force plate. EMG test activity was normalized as a ratio of MVC activity.

RESULTS

Postural parameters (mean center of pressure displacement speed) were poorer and sEMG activity higher in anterior THA than asymptomatic subjects (p<0.005). On the BEC test, GMax and GMed activity was higher on both operated and non-operated sides than in asymptomatic controls (respectively, 0.15±0.12 and 0.12±0.6 versus 0.07±0.06 for GMax, and 0.13±0.08 and 0.13±0.08 versus 0.08±0.05 for GMed; p<0.05). On unipodal tests, both UOP and UnOP GMed activities were higher than in controls (respectively, 0.51±0.3 and 0.48±0.27 versus 0.28±0.13; p<0.04); GMax and TFL activities were higher than in controls only on the UOP tests (respectively, 0.49±0.43 versus 0.24±0.18, and 0.23±0.17 versus 0.12±0.16; p<0.05).

DISCUSSION

sEMG activity in the hip abductors, which are the main stabilizing muscles for the pelvis, is increased following anterior THA, in parallel with impaired postural parameters. This finding may be due to intraoperative TFL and S neuromuscular spindle lesion. The present preliminary study is to be followed up by a comparison of all 3 common minimally invasive approaches (anterior, anterolateral and posterior) using the same study protocol.

LEVEL OF EVIDENCE

III, prospective case-control study.

Balance and quality of life after total knee arthroplasty

OBJECTIVE

To evaluate the change in balance and quality of life in patients undergoing total knee arthroplasty for primary gonarthrosis.

METHOD

Patients aged 60 years or older were evaluated in relation to the balance and quality of life before total knee arthroplasty and six months after surgery. To assess balance, this study used the Motor Scale Test for the Elderly; quality of life was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire and the Short Form Health Survey. A control group consisting of healthy adults, age- and gender-paired, was used to compare the balance after surgery results.

RESULTS

Twenty-eight patients completed the study, of a total of 37 arthroplasties. The mean age was 70.18 ± 6.17 years. All variables were statistically significant (p ≤ 0.05) for improved balance and quality of life after arthroplasty. It was observed that, after knee arthroplasty, the level of balance does not reach that expected for healthy individuals (p ≤ 0.05).

CONCLUSION

Total knee arthroplasty is effective at improving balance six months after surgery, as well as all domains of quality of life. However, it is not able to restore balance to a level comparable to that of healthy individuals.

Balance performance in older adults with hip osteoarthritis: A systematic review

BACKGROUND

The hip is one of the most common joints affected by osteoarthritis (OA) and it has been identified as a key risk factors for falls. Physical impairments associated with OA, such as joint pain, muscle weakness, joint stiffness and sensory dysfunction, can all negatively affect balance and increase risk of falling.

QUESTION

Is balance performance altered in older adults with hip osteoarthritis? To determine whether static, dynamic, reactive or functional balance performance is altered in older people with hip osteoarthritis.

METHODS

Quantitative measures of postural control, including clinical and lab-based assessment of static, dynamic, reactive and/or functional balance performance, compared with a healthy control group or to the asymptomatic limb.

RESULTS

A total of 5407 articles were identified and 14 papers were included (10 with standardised mean different (SMD) data, four without SMD data). Based on data from single studies, there were medium/large effects for increased medio-lateral displacement when standing with eyes open, increased anterior-posterior and total sway path length when standing with eyes closed, greater overall instability when standing on an unstable surface, and increased displacement toward the stance leg in a lateral step in hip OA compared with controls.

CONCLUSION

Balance impairments were identified in some measures, limiting the conclusions as to whether balance deficits are a problem in hip OA. Inconsistent findings suggest that balance may not be a primary contributor to increased falls risk in older adults with hip OA. Other factors, such as musculoskeletal deficits, may contribute to higher falls rate in this population.

The Assessment of Static Balance in Patients after Total Hip Replacement in the Period of 2-3 Years after Surgery

Introduction

The aim of this study was to assess static balance of patients after Total Hip Replacement (THR) compared with the age-matched, asymptomatic control group, considering the subject's gender and the time since the surgery.

Materials and Methods

The Total Hip Replacement (THR) group consisted of 55 subjects (mean age: 56.3 ± 8.7 years) and the control group consisted of 48 subjects (mean age: 58 ± 6.2 years). For the assessment of static balance, a stabilometric force platform was used. All subjects performed two 30-second trials in the double-leg stance position with eyes opened and closed. In the study group, the stabilometric assessment was performed once within the period of 24 to 36 months after the surgery.

Results

Subjects from the study group had significantly increased mediolateral COP velocity in the test with eyes opened, as well as the values of most of the COP parameters (excluding COP path area) in the test with eyes closed, compared to the control group. Higher values of the selected COP parameters were observed in the male subjects from the study group.

Conclusion

In contrast to a number of papers, our study revealed some deficits in static balance in patients after THR up to 2-3 years after surgery.

Does hip joint positioning affect maximal voluntary contraction in the gluteus maximus, gluteus medius, tensor fasciae latae and sartorius muscles?

BACKGROUND

Minimally invasive total hip arthroplasty (THA) is presumed to provide functional and clinical benefits, whereas in fact the literature reveals that gait and posturographic parameters following THA do not recover values found in the general population. There is a significant disturbance of postural sway in THA patients, regardless of the surgical approach, although with some differences between approaches compared to controls: the anterior and anterolateral minimally invasive approaches seem to be more disruptive of postural parameters than the posterior approach. Electromyographic (EMG) study of the hip muscles involved in surgery [gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S)] could shed light, the relevant literature involves discordant methodologies. We developed a methodology to assess EMG activity during maximal voluntary contraction (MVC) of the GMax, GMed, TFL and sartorius muscles as a reference for normalization. A prospective study aimed to assess whether hip joint positioning and the learning curve on an MVC test affect the EMG signal during a maximal voluntary contraction.

HYPOTHESIS

Hip positioning and the learning curve on an MVC test affect EMG signal during MVC of GMax, GMed, TFL and S.

METHODS

Thirty young asymptomatic subjects participated in the study. Each performed 8 hip muscle MVCs in various joint positions recorded with surface EMG sensors. Each MVC was performed 3 times in 1 week, with the same schedule every day, controlling for activity levels in the preceding 24h. EMG activity during MVC was expressed as a ratio of EMG activity during unipedal stance. Non-parametric tests were applied.

RESULTS

Statistical analysis showed no difference according to hip position for abductors or flexors in assessing EMG signal during MVC over the 3 sessions. Hip abductors showed no difference between abduction in lateral decubitus with hip straight versus hip flexed: GMax (19.8±13.7 vs. 14.5±7.8, P=0.78), GMed (13.4±9.0 vs. 9.9±6.6, P=0.21) and TFL (69.5±61.7 vs. 65.9±51.3, P=0.50). Flexors showed no difference between hip flexion/abduction/lateral rotation performed in supine or sitting position: TFL (70.6±45.9 vs. 61.6±45.8, P=0.22) and S (101.1±67.9 vs. 72.6±44.6, P=0.21). The most effective tests to assess EMG signal during MVC were for the hip abductors: hip abduction performed in lateral decubitus (36.7% for GMax, 76.7% for GMed), and for hip flexors: hip flexion/abduction/lateral rotation performed in supine decubitus (50% for TFL, 76.7% for S).

DISCUSSION

The study hypothesis was not confirmed, since hip joint positioning and the learning curve on an MVC test did not affect EMG signal during MVC of GMax, GMed, TFL and S muscles. Therefore, a single session and one specific test is enough to assess MVC in hip abductors (abduction in lateral decubitus) and flexors (hip flexion/abduction/lateral rotation in supine position). This method could be applied to assess muscle function after THA, and particularly to compare different approaches.

LEVEL OF EVIDENCE

III, case-matched study.

The effect of total knee arthroplasty on patients' balance and incidence of falls: a systematic review

PURPOSE

Despite the high incidence of falls in patients with OA, few studies have explored whether falls risk is affected after patients undergo total knee arthroplasty (TKA). Therefore, the aim of this systematic review was to identify the extent of the effects of TKA on balance and incidence of falls by critically reviewing the available literature.

METHODS

A systematic review of published literature sources was conducted up to March 2014. All studies assessing balance and incidence of falls after TKA (without physiotherapeutic intervention) were included. The methodological quality of each study was reviewed using the Critical Appraisal Skill Programme tool.

RESULTS

Thirteen studies were included, comprising of ten cohort studies (Level II) and three studies with Level of evidence III.

CONCLUSIONS

Findings provide evidence that TKA improves significantly single-limb standing balance (~60%) and dynamic balance up to 1-year following surgery (Level of evidence II). Moreover, TKA influences positively fear of falling and incidence of falls by switching 54.2 % of pre-operative fallers to post-operative non-fallers (Level of evidence II-III). It is highlighted that knee extension strength, proprioception and symmetrization of postural strategies have not fully recovered post-TKA and influence balance performance. Clinically, these persistent deficits need to be mitigated by physiotherapy even before TKA takes place.

Short-term comparison of postural effects of three minimally invasive hip approaches in primary total hip arthroplasty: Direct anterior, posterolateral and Röttinger

INTRODUCTION

There is renewed interest in total hip arthroplasty (THA) with the development of minimally invasive approaches. The anterior and Röttinger approaches are attractive for their anatomical and minimally invasive character, but with no comparative studies in the literature definitely suggesting superiority in terms of quality of functional recovery. We therefore performed a case-control study, assessing: 1) whether the postural parameters of patients operated on with the anterior, Röttinger and posterior minimally invasive approaches were similar to those of asymptomatic subjects, and 2) whether there were any differences in postural parameters between the three approaches at short-term follow-up.

HYPOTHESIS

We hypothesized that the anterior and Röttinger approaches are less disruptive of postural parameters than the posterior approach.

METHODS

Seventy subjects (44 primary THA patients and 26 asymptomatic control subjects) were enrolled. Operated subjects were divided into 3 experimental groups corresponding to the 3 minimally invasive approaches: posterior (n=14), anterior (n=15) and Röttinger (n=15). Two single-leg stance tests (left followed by right leg stance; 10s per test) were carried out on a stabilometric platform, within 2months after surgery for all THA patients, and for controls. Six significant parameters were selected for statistical analysis: test performance, mediolateral and anteroposterior displacements of the center of pressure (CP), path length, average CP displacement speed, and the ellipse containing 95% of CP projections. Non-parametric statistical tests were used to compare groups.

RESULTS

There was no difference between the 3 study groups and the control group according to age, gender, BMI, or side (or between study groups regarding WOMAC score). No significant differences between approaches were found for success on postural tests (P=0.14). Subjects operated on with the anterior or Röttinger approach showed significant differences from asymptomatic subjects for 2 postural parameters: path length (Röttinger P=0.04, anterior P=0.03) and average CP displacement speed (Röttinger P=0.04, anterior P=0.03). Subjects operated on through the posterior approach showed no significant differences from asymptomatic subjects.

DISCUSSION

The study hypothesis, that the anterior and Röttinger approaches for hip arthroplasty are less disruptive of postural parameters than the posterior approach, was not confirmed. The anterior and Röttinger approach groups showed higher average CP displacement speed and path length, suggesting that they use up more energy resources to maintain static balance. The posterior approach had the least impact on postural parameters in the first 2 postoperative months.

LEVEL OF EVIDENCE

III, case-control study.

Changes of body balance before and after total knee arthroplasty in patients who suffered from bilateral knee osteoarthritis

PURPOSE

It is still controversial whether simultaneous or staged total knee arthroplasty (TKA) is most desirable for patients with bilateral knee osteoarthritis. We retrospectively evaluated changes in balance among patients with bilateral osteoarthritis who underwent staged TKA using a gravicorder.

METHODS

Patients were stratified into two groups: the unilateral group (UG) (22 patients) consisted of patients who did not undergo a second TKA within 24 months of the first TKA, and the bilateral group (BG) (20 patients) were those who had a second TKA within 12 months after initial TKA.

RESULTS

The mean gravity center position (GCP), which indicates the translation of GCP in the mediolateral direction between pre- and post-TKA shifted to the operative side in both groups after initial surgery. While the GCP was maintained on the same side in UG over 2 years follow-up, in BG it moved to the opposite side and approached a central position after the second TKA. Locus length of GCP (LG), which indicates postural control function by proprioceptive reflex showed significant improvement after initial TKA in UG, while BG showed significant improvement after the second TKA.

CONCLUSIONS

The degree of LG improvement after initial TKA may indicate the necessity of a second TKA for patients with bilateral osteoarthritis. The current study suggests that simultaneous bilateral TKA is not always necessary for patients with bilateral knee arthritis, and that properly performed rehabilitation such as improving postural sway after initial TKA might attenuate the timing for the second TKA.

Modifications of muscle synergies and spinal maps due to absence of visual feedback in patients with unilateral vestibular disease

The present study aimed at describing the modifications of muscle synergies and spinal activity due to the absence of visual feedback, in patients affected by unilateral vestibular disease. Patients were tested both during unperturbed quite stance and walking while the activity of 7 bilateral muscles, from the leg to the trunk, were recorded for the estimation of muscle synergies and spinal activity. Results showed that during locomotion the absence of visual feedback did not significantly modify either the principal roles underlying muscle activity (i.e., synergies) or the spinal bursts. Conversely, during the upright stance, the absence of visual feedback involved a significant coupling of ankle dorsi- and plantar-flexor muscle groups with a consequent shift of the motoneuronal (MN) activity toward most caudal segments. Results revealed that the muscle synergies are able to document an increased activity of sensory-motor afferences leading a more intense role of the forward based mechanism underlying balance control in vestibular patients.