Postural responses following a rotational support surface perturbation, following knee joint replacement: frontal plane rotations

Does the Type of Knee Arthroplasty Affect the Patient's Postural Stability?

Background and Objectives: The aim of this study was to assess postural stability in patients after total and unicompartmental knee arthroplasties. Materials and Methods: The study included 40 women who had undergone knee arthroplasties-20 women who had undergone total knee arthroplasty (TKA) (mean age 63.47 ± 2.17) and 20 women who had undergone unicompartmental knee arthroplasty (UKA) (mean age 64.65 ± 1.93). The comparison group consisted of 20 healthy women aged 60-69 years (mean age 64.45 ± 3.12). The average time from surgery to stabilometry was 14.4 months. Each patient underwent stabilography using a single-plate stabilography platform, which included both Romberg's test and a dynamic test. Additionally, the WOMAC scale was administered, where patients assessed their condition both before surgery and at the present time. Results: The averaged Romberg's test results show a slight displacement in the center of mass (COM) toward the forefoot and towards the right limb in both the TKA and UKA groups. The WOMAC scale results showed significant improvement and satisfactory functional outcomes in both groups. Conclusions: The study indicated that one year after surgery, patients in both groups required a larger base of support to maintain postural control. However, the results for the UKA group were more similar to those of healthy individuals.

The Effect of Total Knee Replacement on Dual-Task Gait Performance in Older Adults

OBJECTIVE

Total knee replacement (TKR) is a common solution for patients with advanced knee osteoarthritis (OA). Still, fall rates remain relatively high after surgery. TKR may alter pain and knee function, balance control, and proprioception. However, given the role of complex (dual-task) walking in fall prediction for older adults, it is unknown how TKR alters the attentional demand of walking in older adults. The goal of this study was to examine the effect of TKR on dual-task walking among older adults.

METHODS

Participants were evaluated 1 month before surgery and 4.5 months after surgery. Participants walked along an instrumented 7-meter path for 1 minute with and without a cognitive task (serial-3 subtraction). Pain and knee function, knee proprioception, dynamic balance, and balance confidence, as well as dual-task costs (DTC) were compared before and after the surgery and factors associated with change in gait DTCs were assessed.

RESULTS

Thirty-eight participants completed the study (age 72.6 years, SD = 4.9; 11 men). A significant decrease in pain was found following TKR, with no change in balance, balance confidence, or proprioception. There were no differences in gait DTCs before and after the surgery. However, change in dynamic balance, specifically reactive postural control and dynamic gait, predicted changes in gait speed and stride time DTCs.

CONCLUSION

The absence of an effect of TKR on gait DTCs can potentially underlie increased fall risk after TKR. Results from this study emphasize the significance of balance as a measure and focal point for rehabilitation after TKR.

IMPACT

This study contributes to our understanding of the attentional cost of walking in people before and after TKR, as well as to factors associated with it. Results from this work can assist formulation of rehabilitation programs for people with knee OA.

Association between postoperative fall history and toe grip strength in patients after total knee arthroplasty: A prospective observational study

BACKGROUND

Factors associated with falls after total knee arthroplasty (TKA) have been rarely reported. The aim of this study was to identify factors that influence the incidence of falls after TKA, focusing on toe grip strength (TGS) in particular, which has been associated with falls in older adults.

METHODS

217 patients who underwent TKA were included and followed up for 1 year. Main study outcome measures were the presence or absence of falls within 1 year after TKA. Multiple logistic regression analysis was used with postoperative falls as the dependent variable and preoperative falls and postoperative TGS on the affected sides as independent variables.

RESULTS

170 (43 and 127 in the fall and non-fall groups) patients were included in the analysis. The presence of a preoperative falls history before TKA and a weak postoperative affected TGS indicated an increased susceptibility of the patient to fall postoperatively.

CONCLUSIONS

Results of the current study revealed the association between postoperative TGS and postoperative falls. We highlight the importance of preoperative fall monitoring and postoperative TGS evaluation to prevent falls after TKA.

Reliability, validity, and minimal detectable change of the Step Test in patients with total knee arthroplasty

BACKGROUND

Step Test (ST) is frequently used to assess dynamic balance and locomotor function in clinical practice.

AIMS

This study aimed to determine the concurrent validity, reliability, and minimal detectable change (MDC) of the ST in patients with total knee arthroplasty (TKA).

METHODS

The study included 56 patients with TKA. The intraclass correlation coefficient (ICC) was used to assess the test-retest reliability of the ST. The correlations of the ST with timed up and go (TUG) and 10-m walk test (10MWT) were assessed for concurrent validity.

RESULTS

Test-retest (ICC 0.90) reliability of the ST was determined to be excellent. The SEM and MDC₉₅ values of test-retest reliability were 0.76 and 2.11, respectively. A significantly moderate correlation was found between the ST and TUG (p < 0.05, r: - 0.69), and 10MWT (p < 0.05, r: - 0.67).

CONCLUSION

The ST is a valid and reliable method in the assessment of dynamic balance ability and locomotor function in patients with TKA. The ST can be used to quantify changes in dynamic balance level and locomotor function in patients with TKA.

Does Total Knee Arthroplasty Positively Affect Body Static-Dynamic Balance and Fall Risk Parameters in Patients With Satisfactory Functional Scores?

Objective The aim of this study was to determine the balance problems and risk of falling by using digital or computerized methods in patients who underwent total knee arthroplasty (TKA) and have satisfactory functional scores in the early postoperative period. Methodology A total of 31 participants (24 women, seven men; mean age: 61.93 ±10.75 years; range: 49-82 years) who underwent unilateral TKA were included. The fall risk was evaluated using the time up-and-go (TUG) test and computerized platforms. Patient-reported pain, stiffness, and physical functional outcome measures [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Score (OKS)] and posture (New York Posture Rating Chart) were evaluated. Results Based on the WOMAC scores, there was a significant impact on self-reported pain (p˂0.001), function (p=0.001), and stiffness (p=0.001) between preoperative and postoperative results. The OKS (p=0.006) and the TUG score (p=0.004) improved significantly, but the posture scores remained the same after the surgery. There was a statistically significant difference between the preoperative and third-month postoperative test results of the stabilometric test, bipedal opened eye, bipedal closed eye, monopedal right, and monopedal left foot static balance tests (p˂0.05). However, the disequilibrium and equilibrium dynamic balance values ​​remained unchanged three months after TKA. Conclusions Satisfactory functional scores according to WOMAC or OKS were achieved in the early postoperative period. However, posture and dynamic balance problems related to falling risk continued to persist in the same period. Although the TUG test results were statistically significant, they also showed fall risk values. Fall risk and postural problems should be analyzed objectively using computerized methods. Early rehabilitation programs after TKA in elderly individuals should be designed accordingly and close attention must be paid to fall risks.

Degenerative cervical myelopathy delays responses to lateral balance perturbations regardless of predictability

The aim of this study was to quantify balance impairments in standing in people with degenerative cervical myelopathy (PwDCM) in response to external perturbations. PwDCM have damage to their spinal cord due to degeneration of the cervical vertebral column, but little is known about balance. Balance was quantified by capturing kinetics, kinematic, and electromyographic data during standing in response to lateral waist pulls. Participants received pulls during predictable and unpredictable contexts in three stance widths at two magnitudes. In response to lateral waist pulls, PwDCM had larger center of mass excursion (P < 0.001) and delayed gluteus medius electromyography onset (P < 0.001) and peak (P < 0.001) timing. These main effects of history of myelopathy were consistent across predictability, stance width, and magnitude. A multilinear regression determined that gluteus medius peak timing + tibialis anterior peak timing most strongly predicted center of mass excursion (R² = 0.50, P < 0.001). These data suggest that PwDCM have delays in generating voluntary and reactive motor commands, contributing to balance impairments. Future rehabilitation strategies should focus on generating rapid muscular contractions. Additionally, frontal plane postural control is regulated by the gluteus medius and the tibialis anterior, whereas other muscles (e.g. gluteus minimus, ankle invertors/evertors) not studied here may also contribute.NEW & NOTEWORTHY Frontal plane reactive postural control is impaired in persons with degenerative cervical myelopathy because of delayed muscle responses. Additionally, postural control varies across stance width, predictability, and perturbation magnitude.

Dynamic stability during stair negotiation after total knee arthroplasty

BACKGROUND

The assessment of dynamic stability is crucial for the prevention of falls in the elderly and people with functional impairments. Evidence that total knee arthroplasty improves balance in patients with severe osteoarthritis is scarce and no information exists about how the surgery affects dynamic stability during stair negotiation.

METHODS

This study aims to investigate if patients before and one year after surgery are less stable compared to asymptomatic controls. Seventeen control and twenty-seven patient participants with end-stage knee osteoarthritis that were scheduled to undergo unilateral total knee arthroplasty were recruited in this study. Participants' assessment was carried out by means of marker-based optical full-body motion capture with force platforms. The extrapolated Centre of mass and the margin of stability metrics were used to examine dynamic stability during stair ascent and descent.

FINDINGS

Patient participants, during both pre-operative and post-operative assessments, were equally balanced to the asymptomatic controls during stair gait (p > .188). Additionally, the patients' overall stability did not improve significantly one year after arthroplasty surgery (p > .252).

INTERPRETATION

Even if pain from arthritis and fear of falling is decreased following surgery, our results indicate that stability in stair walking in not affected by osteoarthritis and total knee arthroplasty.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02422251.

Clinical and Biomechanical Efficacies of Mechanical Perturbation Training After Anterior Cruciate Ligament Rupture

CONTEXT

Manual perturbation training improves knee functional performance and mitigates abnormal gait in patients with anterior cruciate ligament (ACL) rupture. However, manual perturbation training is time- and labor-intensive for therapists.

OBJECTIVE

To investigate whether perturbation training administered using a mechanical device can provide effects similar to manual training on clinical measures and knee biomechanics after ACL rupture.

DESIGN

Prospective cohort (therapeutic) study. A 2 × 2 analysis of variance was used for statistical analysis.

SETTING

A clinical and biomechanical laboratory.

PATIENTS

Eighteen level I/II patients with acute ACL ruptures participated in this preliminary study.

INTERVENTION

Nine patients received mechanical perturbation training on an automated mechanical device (mechanical group), and 9 patients received manual perturbation training (manual group).

OUTCOME MEASURES

Patients completed performance-based testing (quadriceps strength and single-legged hop tests), patient-reported questionnaires (Knee Outcome Survey-Activities of Daily Living Scale, Global Rating Score, and International Knee Documentation Committee 2000), and 3-dimensional gait analysis before (pretesting) and after (posttesting) training.

RESULTS

There was no significant group-by-time interaction found for all measures (P ≥ .18). Main effects of time were found for International Knee Documentation Committee 2000 (pretesting: 69.10 [10.95], posttesting: 75.14 [7.19]), knee excursion during weight-acceptance (pretesting: 16.01° [3.99°]; posttesting: 17.28° [3.99°]) and midstance (pretesting: 14.78° [4.13°]; posttesting: 16.92° [4.53°]) and external knee-flexion moment (pretesting: 0.43 [0.11] N m/kg/m; posttesting: 0.48 [0.11] N m/kg/m) (P ≤ .04). After accounting for pretesting groups' differences, the mechanical group scored significantly higher on triple hops (mechanical: 96.73% [6.65%]; manual: 84.97% [6.83%]) and 6-m timed hops (mechanical: 102.07% [9.50%]; manual: 91.21 [9.42%]) (P ≤ .047) compared with manual group.

CONCLUSION

The clinical significance of this study is the mechanical perturbation training produced effects similar to manual training, with both training methods were equally  effective at improving patients' perception of knee function and increasing knee excursion and external flexion moment during walking after acute ACL rupture. Mechanical perturbation training is a potential treatment to improve patients' functional and biomechanical outcomes after ACL rupture.

Comparison of sit-to-stand and static standing balance ability between patients with total knee arthroplasty and elderly healthy subjects

BACKGROUND

Identifying the functional status of patients after total knee arthroplasty is important. This study aimed to examine the differences in sit-to-stand and static standing ability balance between patients who underwent total knee arthroplasty and healthy participants.

METHODS

Twenty patients (mean age 70.05 years) who underwent total knee arthroplasty and 20 healthy participants (mean age 69.20 years) participated in this study. To assess the participants' sit-to-stand, the Good Balance System (Metitur Ltd, Finland) was used to measure each participant's mediolateral center of pressure (COP) displacement and time required to complete the sit-to-stand movement. To assess the participants' static standing balance, the Good Balance System was used to measure each patient's mediolateral COP displacement, anteroposterior COP displacement, and velocity moment when standing with eyes open and with eyes closed.

RESULTS

A significant difference was found in the mediolateral COP displacement and the time required to complete the sit-to-stand movement in the two groups (P< 0.05). A significant difference was also found in the mediolateral and anteroposterior COP displacement and the velocity moment when standing with eyes open and with eyes closed in the two groups (P< 0.05).

CONCLUSIONS

Patients who had total knee arthroplasty showed decreased sit-to-stand and static standing balance ability compared with the control group in the initial period after surgery.

Falls After Total Knee Arthroplasty: Frequency, Circumstances, and Associated Factors-A Prospective Cohort Study

BACKGROUND

Individuals with total knee arthroplasty (TKA) often experience pain and reduced balance control, which may predispose them to greater fall risk.

OBJECTIVE

The objective of this study was to determine the frequency and circumstance of falls and fall-related risk factors within a 6-month follow-up period in individuals after TKA.

DESIGN

This study was a prospective cohort study.

METHODS

Knee proprioception, the Balance Systems Evaluation Test, knee pain, knee extension and flexion muscle strength, knee range of motion, and balance confidence were evaluated in 134 individuals (39 men, 95 women; mean age = 66.3 years [SD = 6.6 years]) 4 weeks after TKA. Monthly follow-up sessions, via face-to-face or telephone interviews, were implemented to obtain data on fall incidence over 6 months.

RESULTS

Twenty-three individuals after TKA (17.2%) sustained at least 1 fall during the 6-month follow-up period. The median time of the first fall episode was 15 weeks after TKA. Of the 31 fall episodes, most occurred during walking (67.7%). Slipping (35.5%) and tripping (35.5%) were identified as the most frequent causes of falling. Most falls occurred at home (45.2%) or another indoor environment (29.0%). Multivariate binary logistic regression revealed that younger age (odds ratio: 0.91), reduced proprioception of the knee that had undergone surgery ("operated knee") (odds ratio: 1.62), reduced sensory orientation (odds ratio: 0.92), and greater operated knee pain (odds ratio: 1.68) were significantly associated with more falls during the follow-up period.

LIMITATIONS

The results of this study may be generalizable up to 6 months after TKA.

CONCLUSIONS

Intervention efforts should target deficits in knee proprioception and sensory orientation and operated knee pain to prevent future falls in individuals with TKA.

Reported balance confidence and movement reinvestment of younger knee replacement patients are more like younger healthy individuals, than older patients

This study focused on differences between the rapidly growing younger (<65 years old) and older (>65 years old) total knee replacement (TKR) patients for measures of balance confidence, movement reinvestment, and functional mobility. Fifty-nine participants, including twenty-nine primary unilateral TKR patients (six months post-TKR) formed the four experimental groups: 1) Younger TKR Patient (YP), 2) Younger Control (YC), 3) Older TKR Patient (OP), and 4) Older Control (OC). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Oxford Knee Score (OKS), Activities-specific Balance Confidence scale (ABC), the Movement-Specific Reinvestment Scale (MSRS), and the Timed Up and Go (TUG) test were measured. The YP group reported a significantly lower WOMAC score (p < 0.001), and higher perceived knee joint function (p = 0.001), compared to the OP group. The YP group also reported significantly higher balance confidence (p < 0.001) and less movement reinvestment (p = 0.001) than the OP group. TUG durations revealed that the YP group had significantly higher functional mobility compared to the OP group (p = 0.001). The YP group did not differ from the YC group across any of these measures (p > 0.05). These results identify a clear distinction between younger and older TKR patients for fall risk and TKR outcome, which argues that age should be a factor clinicians take into account when addressing the management and care of individuals recovering from TKR.

The effect of primary total knee arthroplasty on the incidence of falls and balance-related functions in patients with osteoarthritis

Knee osteoarthritis (OA) is an established risk factor for falls and balance impairment. This study investigated the incidence of falls, balance-related outcomes and risk factors for falls before and after primary total knee arthroplasty (TKA). Three hundred seventy-six OA patients scheduled to undergo TKA were included. Falls data within the preoperative, first postoperative and second postoperative years were collected, balance-related functions were assessed using the Assessment of Quality of Life (AQoL), WOMAC, Falls Efficacy Scale International (FES-I), Activities-specific Balance Confidence (ABC), knee extension strength, Berg Balance Scale (BBS) and Timed Up and Go (TUG) before surgery and 1 and 2 years after surgery. Compared with preoperative values, the incidence of falls significantly decreased (14.89%, 6.23% and 3.14% within the preoperative, first postoperative and second postoperative years, respectively) and the AQoL, WOMAC, FES-I, ABC, knee extension strength, BBS and TUG significantly improved after TKA. Logistic regression analysis revealed that Kellgren-Lawrence grade ≥ 3 of the contralateral knee was an independent risk factor for falls before and after TKA. Conclusively, primary TKA is associated with a reduced incidence of falls and improved balance-related functions, and the contralateral knee should be considered in the design of fall-prevention strategies in patients with OA.

After total knee replacement younger patients demonstrate superior balance control compared to older patients when recovering from a forward fall

BACKGROUND

National joint replacement registries have reported a substantial growth in younger knee osteoarthritic patients (<55years old) undergoing total knee replacement, however this younger population is generally understudied. Importantly, studies examining experimentally controlled perturbation have shown age-related differences between younger and older healthy adults, whether similar age-related differences exist among total knee replacement patients is unknown.

METHODS

A total of 59 participants, including 29 unilateral total knee replacement patients (six-months post-surgery) made up the four experimental groups: 1) younger patient (54.3 (SD 7.9) years), 2) younger control (55.2 (SD 4.0) years), 3) older patient (76.9 (SD 4.7) years), and 4) older control (77.7 (SD 4.1) years). Using a tether-release method to perturb balance and simulate a forward fall, center of mass and stepping characteristics were analyzed.

FINDINGS

Younger patients recovered following the perturbation with a significantly smaller center of mass displacement compared to the older patients (14.85 (SD 0.01) v. 18.13 (SD 0.02) %ht, p=0.02); utilizing a longer (0.43 (SD 0.02) v. 0.39 (SD 0.03) m, p<0.001) and higher velocity (2.01 (SD 0.2) v. 1.59 (SD 0.2) m/s, p=0.001) recovery step. Importantly, younger patients did not differ significantly from the younger controls in center of mass displacement or recovery step characteristics (p>0.05).

INTERPRETATION

The younger patients demonstrated superior center of mass control in response to a forward perturbation, suggesting that younger patients would be at a reduced risk of falling when recovering from a forward-directed postural perturbation compared to older patients.

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.

Force-plate analyses of balance following a balance exercise program during acute post-operative phase in individuals with total hip and knee arthroplasty: A randomized clinical trial

Objectives:

Typical rehabilitation programs following total hip arthroplasty and total knee arthroplasty include joint range of motion and muscle-strengthening exercises. Balance and balance exercises following total hip arthroplasty and total knee arthroplasty have not received much attention. The purpose of this study was to determine whether an intervention of balance exercises added to a typical rehabilitation program positively affects patients’ balance.

Methods:

A total of 63 patients were provided with outpatient physical therapy at their home. Patients were randomly assigned to either typical (n = 33) or balance (n = 30) exercise group. The typical group completed seven typical surgery-specific joint range of motion and muscle-strengthening exercises, while the balance group completed the typical exercises plus three balance exercises. After 5 weeks of administering the rehabilitation program, patients’ balance was assessed on a force plate using 95% ellipse area of the center of pressure amplitude.

Results:

Patients in the balance group demonstrated significant reduction in the 95% ellipse area for the anterior and posterior lean standing conditions (p < 0.01).

Conclusion:

Balance exercises added to the typical outpatient physical therapy program resulted in significantly greater improvements in balance for participants with total hip arthroplasty or total knee arthroplasty, compared to the typical exercise program alone. Physical therapists might consider the use of balance exercises to improve balance in individuals in the acute post-operative phase following total hip arthroplasty or total knee arthroplasty.

Greek Physiotherapists' Perspectives on Rehabilitation Following Total Knee Replacement: a Descriptive Survey

BACKGROUND AND PURPOSE

In Greece, as in many countries, there is a scarcity of evidence in the type of physiotherapy services offered for the rehabilitation of total knee replacement (TKR). Despite the number of TKRs annually performed in Greece (over 10,000), there are no available clinical guidelines as to the content of best physiotherapy practice. The aim of this nationwide survey undertaken by physiotherapists treating TKR patients post-operatively was to record standard practice and services available in Greece.

METHODS

Design: cross-country survey Ten per cent of all registered physiotherapists working in public/private sectors were recruited. The developed survey comprised of questions regarding therapists' profile, protocols implemented at different stages of rehabilitation and the aims and modalities used.

RESULTS

A 58.7% response rate was achieved, where 36% (47/132) of respondents were treating patients in the inpatient phase and 64% (85/132) after hospital discharge. Patients in Greece are discharged with a home-based exercise program (56.7%) and, to a lesser extent, are referred to rehabilitation centres (13.3%). Strengthening, range of movement and functionality seemed to be the primary goals especially in the inpatient phase, whereas in the outpatient phase, apart from the larger differences identified, functionality and balance training were more frequently reported.

CONCLUSIONS

No significant variations in practice were found during inpatient rehabilitation, whilst there seemed to be diversity across outpatient physiotherapy programs. The current survey suggests that patient's general health and psychological and behavioural issues are the criteria by which physiotherapists select the volume of implemented exercise and progression. However, no specific guidelines were followed. Copyright © 2016 John Wiley & Sons, Ltd.

Proprioception and Knee Arthroplasty: A Literature Review

Proprioceptive mechanoreceptors provide neural feedback for position in space and are critical for three-dimensional interaction. Proprioception is decreased with osteoarthritis of the knees, which leads to increased risk of falling. As the prevalence of osteoarthritis increases so does the need for total knee arthroplasty (TKA), and knowing the effect of TKA on proprioception is essential. This article reviews the literature regarding proprioception and its relationship to balance, aging, osteoarthritis, and the effect of TKA on proprioception. Knee arthroplasty involving retention of the cruciate ligaments is also reviewed, as well the evidence of proprioception in the posterior cruciate ligament after TKA.

Assessing Balance Function in Patients With Total Knee Arthroplasty

BACKGROUND

The Balance Evaluation Systems Test (BESTest) is a relatively new balance assessment tool. Recently, the Mini-BESTest and the Brief-BESTest, which are shortened versions of the BESTest, were developed.

OBJECTIVE

The purpose of this study was to estimate interrater and intrarater-interoccasion reliability, internal consistency, concurrent and convergent validity, and floor and ceiling effects of the 3 BESTests and other related measures, namely, the Berg Balance Scale (BBS), Functional Gait Assessment (FGA), and Activities-specific Balance Confidence (ABC) Scale, among patients with total knee arthroplasty (TKA).

DESIGN

This was an observational measurement study.

METHODS

To establish interrater reliability, the 3 BESTests were administered by 3 independent raters to 25 participants with TKA. Intrarater-interoccasion reliability was evaluated in 46 participants with TKA (including the 25 individuals who participated in the interrater reliability experiments) by repeating the 3 BESTests, BBS, and FGA within 1 week by the same rater. Internal consistency of each test also was assessed with Cronbach alpha. Validity was assessed in another 46 patients with TKA by correlating the 3 BESTests with BBS, FGA, and ABC. The floor and ceiling effects also were examined.

RESULTS

The 3 BESTests demonstrated excellent interrater reliability (intraclass correlation coefficient [ICC] [2,1]=.96-.99), intrarater-interoccasion reliability (ICC [2,1]=.92-.96), and internal consistency (Cronbach alpha=.96-.98). These values were comparable to those for the BBS and FGA. The 3 BESTests also showed moderate-to-strong correlations with the BBS, FGA, and ABC (r=.35-.81), thus demonstrating good concurrent and convergent validity. No significant floor and ceiling effects were observed, except for the BBS.

LIMITATIONS

The results are generalizable only to patients with TKA due to end-stage knee osteoarthritis.

CONCLUSIONS

The 3 BESTests have good reliability and validity for evaluating balance in people with TKA. The Brief-BESTest is the least time-consuming and may be more useful clinically.

Postural sway in single-limb and bilateral quiet standing after unilateral total knee arthroplasty

AIM

To investigate whether total knee arthroplasty (TKA) was associated with stability in single-limb stance and whether reduced stability in single-limb stance was associated with increased postural sway in bilateral quiet standing.

METHODS

3D kinematics for center of mass was used to assess postural sway in 23 subjects with TKA and 23 controls. Tests included bilateral quiet standing with and without vision and on a compliant surface, and single-limb stance.

RESULTS

30% of the subjects in the TKA group were unable to maintain single-limb stance for 20s on any leg. Of the 70% in the TKA group able to stand on one leg, mean sway velocity in the medio-lateral direction was marginally higher for the prosthetic side (p=.02), but no differences were found between the TKA and the control group in single-limb stance. Performance in bilateral quiet standing was similar in TKA-subjects, able as well as unable to stand on one leg, and controls. Reduced quadriceps strength in the contralateral leg, higher BMI, and older age predicted failure to maintain single-limb stance.

CONCLUSION

In subjects able to stand on one leg, performance was considered comparable between the prosthetic and contralateral side and between groups. Inability to stand on one leg did not affect postural sway in bilateral quiet standing. The results suggest that inability to maintain single-limb stance is explained by reduced physical capacity rather than the knee condition in itself. The present study emphasizes the importance of physical activity to improve strength and functional capacity.

Effectiveness of balance exercises in the acute post-operative phase following total hip and knee arthroplasty: A randomized clinical trial

Objectives:

To determine the effectiveness of balance exercises in the acute post-operative phase following total hip arthroplasty or total knee arthroplasty.

Methods:

Patients who had total hip arthroplasty (n = 30) or total knee arthroplasty (n = 33) were seen in their residence 1–2 times per week for 5 weeks. At the first post-operative home visit, patients were randomly assigned to either typical (TE, n = 33) or typical plus balance (TE + B, n = 30) exercise groups. The TE group completed seven typical surgery-specific joint range-of-motion and muscle strengthening exercises, while the TE + B group completed the typical exercises plus three balance exercises. Patients were assessed before and 5 weeks after administering the rehabilitation program using four outcome measures: (1) the Berg Balance Scale, (2) the Timed Up and Go test, (3) the Western Ontario McMaster Universities Osteoarthritis Index, and (4) the Activities-specific Balance Confidence Scale.

Results:

Post-intervention scores for all four outcome measures were significantly improved (p < 0.01) over baseline scores. Patients who participated in the TE + B group demonstrated significantly greater improvement on the Berg Balance Scale and the Timed Up and Go tests (p < 0.01).

Conclusion:

Balance exercises added to a typical rehabilitation program resulted in significantly greater improvements in balance and functional mobility compared to typical exercises alone.

Unipedal balance is affected by lower extremity joint arthroplasty procedure 1 year following surgery

Lower Extremity Joint Arthroplasty (LEJA) surgery is an effective way to alleviate painful osteoarthritis. Unfortunately, these surgeries do not normalize the loading asymmetry during the single leg stance phase of gait. Therefore, we examined single leg balance in 234 TJA patients (75 hips, 65 knees, 94 ankles) approximately 12 months following surgery. Patients passed if they maintained single leg balance for 10s with their eyes open. Patients one year following total hip arthroplasty (THA-63%) and total knee arthroplasty (TKA-69%) had similar pass rates compared to a total ankle arthroplasty (TAA-9%). Patients following THA and TKA exhibit better unilateral balance in comparison with TAA patients. It may be beneficial to include a rigorous proprioception and balance training program in TAA patients to optimize functional outcomes.

Functional outcomes of outpatient balance training following total knee replacement in patients with knee osteoarthritis: a randomized controlled trial

Objective:

To evaluate whether balance training after total knee replacement surgery improves functional outcomes and to determine whether postoperative balance is associated with mobility.

Design:

A prospective intervention study and randomized controlled trial with an intention-to-treat analysis.

Setting:

The rehabilitation center of a university-based teaching hospital.

Participants:

A total of 130 patients with knee osteoarthritis who had undergone total knee replacement surgery were recruited to attend an outpatient rehabilitation program. They were randomly allocated to additional balance rehabilitation and functional rehabilitation groups.

Interventions:

During the eight-week outpatient rehabilitation program, both groups received general functional training. Patients in the balance rehabilitation group received an additional balance-based rehabilitation program.

Primary outcome measures:

The functional reach test, single-leg stance test, 10-m walk test, Timed Up and Go Test, timed chair-stand test, stair-climb test, and Western Ontario and McMaster Universities Osteoarthritis Index were measured at baseline, eight weeks (T1), and 32 weeks (T2).

Results:

The balance rehabilitation group patients demonstrated significant improvement in the results of the functional reach test at T1 (37.6 ±7.8 cm) and T2 (39.3 ±9.7 cm) compared with the baseline assessment (11.5 ±2.9 cm) and Timed Up and Go Test at T1 (8.9 ±1.2 seconds) and T2 (8.0 ±1.9 seconds) compared with the baseline assessment (12.5 ±1.8 seconds). Moreover, the balance rehabilitation group patients exhibited significantly greater improvements in balance and mobility than did the functional rehabilitation group patients (all P < 0.001). Furthermore, improved balance was significantly associated with improved mobility at T2.

Conclusion:

Postoperative outpatient rehabilitation with balance training improves the balance, mobility, and functional outcomes in patients with knee osteoarthritis after total knee replacement.

Preoperative asymmetry in load distribution during quiet stance persists following total knee arthroplasty

PURPOSE

Preoperative function has been shown to persist posttotal knee arthroplasty. However, it remains unclear whether asymmetries are task specific. Therefore, we investigated postoperative asymmetries in loading during quiet stance and walking gait.

METHODS

Ten patients with end-stage knee osteoarthritis scheduled for total knee arthroplasty were studied at baseline (preoperative), 6-week, 3- and 6-month postoperative. Load distribution and balance were quantified during quiet stance. Furthermore, dynamic loading was quantified during walking gait. Patient satisfaction was assessed using the Knee Osteoarthritis and injury Outcome Score.

RESULTS

Preoperatively, load distribution was significantly different between limbs, with approximately 70% of the load through the contralateral or 'good' side. Asymmetries persisted and up to 6-month postoperative during quiet stance. No significant change was found in balance. During walking, preoperative loading asymmetry was present; however, no significant postoperative loading asymmetries were identified.

CONCLUSIONS

Total knee arthroplasty does not appear to significantly change load distribution or balance 6-month postoperative during quiet stance; however, during walking gait, symmetry appears to be restored. This could be potentially improved through enhanced rehabilitation.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Improved single-limb balance after total knee arthroplasty

PURPOSE

Unsteady ambulation shortly after total knee arthroplasty (TKA) may cause falling. Postural sway may predict the risk of falling. This prospective single-blinded observational study therefore evaluated the effects of TKA on single-limb standing balance (SLSB) and factors related to change in SLSB.

METHODS

Patients with varus deformity and medial compartment degeneration were evaluated between September and December 2010. The Western Ontario and McMaster Universities Osteoarthritis Index and Kellgren/Lawrence scale were assessed, as were varus angle, number of painful knees, isometric peak torque of the quadriceps femoris, balance index of double limbs, and postural sway of single limbs.

RESULTS

Twelve patients were enrolled and 11 were analysed. The mean ± SD postural sway of single limbs (i.e., SLSB) was reduced significantly after TKA, from 30.3 ± 20.8 cm to 18.5 ± 9.3 cm (p = 0.02). Amelioration was in proportion to pre-operative postural sway (β = 0.92).

CONCLUSIONS

SLSB in patients with varus knees with osteoarthritis was improved significantly 11 days after TKA. Poorer pre-operative SLSB was associated with better post-operative SLSB. TKA may be useful for the immediate reduction of falling in patients with osteoarthritis.

The immediate and long-term effects of a walking-skill program compared to usual physiotherapy care in patients who have undergone total knee arthroplasty (TKA): a randomized controlled trial

PURPOSE

To examine the immediate and long-term effects of a walking-skill program compared with usual physiotherapy on physical function, pain and perceived self-efficacy in patients after total knee arthroplasty (TKA).

METHOD

A single blind randomized controlled trial design was applied. Fifty-seven patients with primary TKA, mean age of 69 years (SD ± 9), were randomly assigned to a walking-skill program emphasizing weight-bearing exercises or usual physiotherapy. Outcomes were assessed before the interventions started at 6 weeks postoperatively (T1), directly after the interventions at 12-14 weeks (T2) and 9 months after the interventions (T3). Walking was the primary outcome, assessed by the 6 min walk test (6MWT). The secondary outcomes were timed stair climbing, timed stands, Figure-of-eight test, Index of muscle function, active knee range of motion, Knee Injury and Osteoarthritis Outcome Score and self-efficacy score.

RESULTS

From T1 to T2, a better 6MWT score was found in favor of the walking-skill program of 39 m (2-76), p = 0.04. The difference between the groups in 6MWT persisted at T3, 44 m (8-80), p = 0.02. No differences in other outcome measures were found.

CONCLUSION

The walking-skill program had better effect on walking than usual physiotherapy. Weight bearing was tolerated. Implications for Rehabilitation Weight-bearing exercises are tolerated by the patients in the early stage after TKA. Physiotherapy that focuses on learning different ways of walking through practice may be a plausible way to train patients after TKA.

Fall incidence and risk factors in patients after total knee arthroplasty

PURPOSE

To prospectively investigate the relationship between physical function and falls among elderly patients who underwent total knee arthroplasty (TKA) and to determine the incidence of falls as well as their risk factors.

METHODS

A total of 108 patients (17 male, 91 female) over 60 years of age who underwent TKA were enrolled and who were living independently in community. 75 patients fulfilled our inclusion criteria and 74 (8 male, 66 female) of them agreed to participate. Baseline assessment (physical examination, physical performance tests, and self-administered questionnaire) were conducted between 6 and 12 months after the last arthroplasty and the follow-up assessment was performed 6 months after the baseline assessment. Monthly pre-stamped postcards were sent to assess the incidence of falls.

RESULTS

Of the 74 patients enrolled, 70 (94.6%) completed a 6-month prospective observation. 23 of 70 patients (32.9%) fell during the observational period. Postoperative range of knee flexion, ranges of knee flexion and extension and ankle plantar flexion were significantly lower in fallers than in non-fallers (P = 0.016, P = 0.037, P = 0.014, respectively). In the multivariate analysis, postoperative range of knee flexion (OR 0.277, 95%CI 0.088-0.869, P = 0.028) and ankle plantar flexion (OR 0.594, 95%CI 0.374-0.945, P = 0.028) were determined to be significant risk factors.

CONCLUSION

Elderly people who underwent TKA are considered more likely to fall compared with healthy elderly people. For patients with limited knee flexion and ankle plantar flexion, improvement of ROM by exercise therapy and patient education regarding the prevention of falls and fractures are considered necessary.

Outcomes before and after total knee arthroplasty compared to healthy adults

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

To measure changes in muscle strength, range of motion, and function from 2 weeks before to 6 months after total knee arthroplasty (TKA) and compare outcomes with data from a control group consisting of healthy adults.

BACKGROUND

Total knee arthroplasty successfully alleviates pain from knee osteoarthritis, but deficits in function can persist long term. How impairments and functional limitations change over the first 6 months after TKA, compared to data from healthy adults, has not been well reported in the literature.

METHODS

Twenty-four patients who underwent a primary unilateral TKA were compared to healthy adults (n = 17). All patients participated in a standardized rehabilitation program following surgery. Isometric quadriceps torque was assessed using an electromechanical dynamometer. Range of motion was measured actively and passively. Functional performance was assessed using the stair-climbing test, timed up-and-go test, 6-minute walk test, and single-limb stance time. Patients underwent testing at 2 weeks preoperatively and at 1, 3, and 6 months postoperatively.

RESULTS

Compared to healthy older adults, patients performed significantly worse at all times for all measures (P<.05), except for single-limb stance time at 6 months (P>.05). One month postoperatively, patients experienced significant losses from preoperative levels in all outcomes. Patients recovered to preoperative levels by 6 months postoperatively on all measures, except knee flexion range of motion, but still exhibited the same extent of limitation they did prior to surgery.

CONCLUSION

The persistent impairments and functional limitations 6 months after TKA with standard rehabilitation suggest that more intensive therapeutic approaches may be necessary to restore function of patients following TKA to the levels of healthy adults.

On the role of knee joint in balance control and postural strategies: effects of total knee replacement in elderly subjects with knee osteoarthritis

This study aimed to evaluate the role of the knee joint in the neurosensory organization of balance control and the generation of postural sensorimotor strategies. Ten patients, aged over 60 years and having undergone unilateral total knee replacement (TKR) for osteoarthritis, and 20 controls were submitted to static and dynamic posturographic tests and to a sensory organization test (SOT) aiming at evaluating postural control in quiet stance and during movement. The patients were submitted to these evaluations after the disappearance of pain (TKR(1)) and at the end of a 6-week rehabilitation program (TKR(2)). Balance control being greatly improved at TKR2 compared to TKR1, the patients attain a quality of postural regulation similar to that of the controls; some postural abnormalities did however persist for the static test. Moreover, SOT values at TKR(2) close to those of the controls highlighted an improvement in motor response, better management in altered proprioceptive information situations, and greater use of the ankle to control balance. This model of intervention on the knee joint, namely knee replacement due to osteoarthritis, has shown that gradual functional sensorimotor restoration after TKR, due to intrasensory proprioceptive compensation either at knee, or at other joint levels (hip/ankle), improves dynamic balance control. This reacquisition allows the knee joint to recover its corrective compensatory role in postural regulation allowing, through neuroplasticity, the modification of muscular activation sequences and, thus, the implementation of anticipatory sensorimotor strategies.

A balance exercise program appears to improve function for patients with total knee arthroplasty: a randomized clinical trial

BACKGROUND

Patients with total knee arthroplasty (TKA) have impaired balance and movement control. Exercise interventions have not targeted these impairments in this population.

OBJECTIVES

The purposes of this study were: (1) to determine the feasibility of applying a balance exercise program in patients with TKA, (2) to investigate whether a functional training (FT) program supplemented with a balance exercise program (FT+B program) could improve physical function compared with an FT program alone in a small group of individuals with TKA, and (3) to test the methods and calculate sample size for a future randomized trial with a larger study sample.

DESIGN

This study was a double-blind, pilot randomized clinical trial.

SETTING

The study was conducted in the clinical laboratory of an academic center.

PARTICIPANTS

The participants were 43 individuals (30 female, 13 male; mean age=68 years, SD=8) who underwent TKA 2 to 6 months prior to the study.

INTERVENTIONS

The interventions were 6 weeks (12 sessions) of a supervised FT or FT+B program, followed by a 4-month home exercise program.

MEASUREMENTS

Feasibility measures included pain, stiffness, adherence, and attrition. The primary outcome measure was a battery of physical performance tests: self-selected gait speed, chair rise test, and single-leg stance time. Secondary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the Lower Extremity Functional Scale.

RESULTS

Feasibility of the balance training in people with TKA was supported by high exercise adherence, a relatively low dropout rate, and no adverse events. Both groups demonstrated clinically important improvements in lower-extremity functional status. The degree of improvement seemed higher for gait speed, single-leg stance time, and stiffness in the FT+B group compared with the FT group.

LIMITATIONS

Due to the pilot nature of the study, differences between groups did not have adequate power to show statistical significance.

CONCLUSIONS

There is a need for conducting a larger randomized controlled trial to test the effectiveness of an FT+B program after TKA.

A prospective observational study of falling before and after knee replacement surgery

BACKGROUND

knee arthritis is a risk factor for falling. Increasing numbers of people are receiving total knee arthroplasty (TKA) but the natural history of falling before and after TKA is unknown.

OBJECTIVE

to prospectively monitor falls in pre- and post-operative TKA patients and to identify independent risk factors for post-operative falling.

DESIGN

a prospective observational study with a 1-year follow-up.

PARTICIPANTS

community-dwelling older people recruited from a regional orthopaedic centre.

METHODS

consecutive patients added to the TKA waiting list who completed monthly falls diaries, pre-operatively and 1 year post-operatively. Data on knee status (WOMAC: pain, stiffness and function), balance confidence (the Activities Balance Confidence Scale-UK-ABC-UK) and mood (Geriatric Depression Scale-GDS) were collected at quarterly intervals.

RESULTS

ninety-nine patients received a primary TKA. 24.2% fell in the last pre-operative quarter (24 patients reported 44 falls) and this decreased to 11.7-11.8% in the first four post-operative quarters. 45.8% of people who fell pre-operatively fell again in the first post-operative year. Higher pre-operative GDS scores and a history of falling were significant independent predictors of post-operative falling.

CONCLUSION

a recent history of falling is common in people undergoing TKA and approximately 45% of patients fall again in the year following surgery. Patients being considered for TKA should be asked about falls history and undergo falls risk assessment and intervention.