Comparison of self-reported knee injury and osteoarthritis outcome score to performance measures in patients after total knee arthroplasty

Accelerometer-based daily physical activity monitoring in patients with postpartum sacroiliac joint dysfunction: a case-control study

Patients with low back pain caused by sacroiliac joint (SIJ) dysfunction have an impaired quality of life, due to reported pain, disability and activity limitations. There is increasing evidence that minimally invasive sacroiliac joint fusion (MISJF) results in improvement in pain, disability and quality of life in these patients. Some studies have reported improvements in daily physical activity following MISJF but based on bias-prone self-reports. Our aim was to provide objective data on daily physical activity in patients with SIJ dysfunction. Daily physical activity in daily life of participants was measured using a triaxial accelerometer for seven consecutive days, before surgery and 3 months after surgery. Recorded daily activities were the daily number of events and total time spent sitting or lying, standing, walking, cycling, high-activity and number of steps and sit-to-stand transfers. The quality of life was assessed by the validated Dutch EQ-5D-5 L-questionnaire. No statistical differences were observed between daily physical activity in patients with SIJ dysfunction before and 3 months after MISJF. As compared to matched controls, high-intensity physical activity was lower in both the pre- and postoperative period (p = 0.007) for patients with SIJ dysfunction. The quality of life improved significantly in patients after MSIJF, from 0.418 to 0.797 (p = 0.021) but did not reach the level of controls (1.000). Daily physical activity in patients with postpartum SIJ dysfunction does not improve 3 months following MISJF, while quality of life does improve significantly. The discrepancy between these two observations is food for new research.

Construct Validity and Responsiveness of Performance-based Tests in Individuals With Knee Osteoarthritis

OBJECTIVES

To assess the construct validity and responsiveness of 3 performance-based tests in individuals with knee osteoarthritis (KOA).

DESIGN

This study has a prospective cohort design.

SETTING

Assessments were administered at the Federal University of São Carlos (Brazil) by 3 different raters.

PARTICIPANTS

A total of 107 participants with KOA were aged ≥40 years (N=107).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

This study assessed the construct validity and responsiveness of 3 performance-based tests: 40-meter fast-paced walk test (40-m FPWT), 11-step stair climb test (11-step SCT), and 30-second chair stand test (30-s CST). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), sedentary behavior (activPAL), and numeric pain rating scale (NPRS) were used as comparator instruments. Measurements were obtained at baseline and after 6 months. The construct validity and responsiveness were calculated using Spearman correlation coefficient within predefined hypotheses based on a panel comprising 5 experts in the field of outcome measurement in KOA.

RESULTS

The three performance-based tests showed excellent (ICC>0.9) reliability (intra and inter); however, only the 40-m FPWT and 11-step SCT were considered valid and responsive because both confirmed >75% of the priori hypotheses. The 30-s CST was not considered valid or responsive because it has not confirmed ≥75% of the priori hypotheses.

CONCLUSION

The 3 performance-based tests are reliable for intra and inter assessments. The 40-m FPWT and 11-step SCT are both valid and responsive for measuring physical function in patients with KOA. The 30-s CST was not considered valid or responsive. Therefore, 40-m FPWT and 11-step SCT can detect changes over time and are indicated for functional assessment in clinical practice.

Hoffa's fat pad resection during total knee arthroplasty does not affect functioning and gait: a double-blind randomized clinical trial

INTRODUCTION

Hoffa's fat pad is considered a source of anterior knee pain and may limit prosthetic knee function. Resection of Hoffa's fat pad in total knee arthroplasty (TKA), however, is controversial, and little is known about the functional outcomes including gait quality. This double-blind randomized controlled trial (i) compared functional recovery between TKAs where Hoffa was resected or preserved, and (ii) compared recovery of self-reported function with objective (gait-related) outcomes.

MATERIALS AND METHODS

Eighty-five patients (age 66.4 ± 8.0 years, 47% women) scheduled to undergo TKA for primary osteoarthritis were randomly assigned to either fat pad resection or preservation. Subjective measures of functioning were assessed at baseline, 6 weeks, 3 months, and 12 months postoperatively and included the Knee Injury and Osteoarthritis Outcome Score (KOOS), Kujala, and visual analog scale (VAS) for pain. Objective measures of functioning were assessed at baseline, 3 months, and 12 months postoperatively and included instrumented range-of-motion and gait analysis. Longitudinal analyses (generalized estimating equations) were used to compare recovery between groups, and chi-square tests compared attainment of minimal clinical important difference (MCID) and patient acceptable symptom state (PASS). Finally, correlation analyses explored associations between subjective and objective recovery in function.

RESULTS

Resection patients showed poorer improvement in KOOS quality of life in the first 6 weeks (B=-10.02, 95% confidence interval (CI) [-18.91, -1.12], p = .027), but stronger improvement in knee extension after 3 months (B = 3.02, 95%CI [0.45, 5.60], p = .021) compared to preservation patients. Regarding MCID or PASS, no differences were noted between groups at 3 and 12 months (all p > .05). Subjective function substantially improved in the first 3 months, while objective outcomes improved only between 3 and 12 months. Moderate to strong correlations were identified between changes in knee flexion and gait with Kujala and KOOS in the resection but not in the preservation group.

CONCLUSIONS

Similar functional outcomes were achieved after TKA with or without resection of Hoffa's fat pad. Hence, removing the fat pad to promote surgical exposure will not affect functional outcomes including gait quality. Functional recovery of objective outcomes was not always consistent with subjective recovery, suggesting that both self-reported as well as objective, gait-related outcomes may provide meaningful information on functional recovery following TKA.

TRIAL REGISTRATION

This clinical trial was prospectively registered under the Netherlands Trial Registry (# NL3638). This registry has recently been replaced by the Dutch Trial Registry where this study can be accessed via https://onderzoekmetmensen.nl/en/trial/20994 .

Characterization of the Relative Change in Objective and Subjective Metrics by Baselining Patients Who Have Wearable Technology Before Total Knee Arthroplasty

BACKGROUND

Wearable sensors and associated supporting technologies (ie, patient applications) can provide both objective (joint position, step counts, etc.) and subjective data (ie, pain scores and patient-reported outcome measures) to track a patient's episode of care. Establishing a subjective and objective baseline of a patient's experience may arguably be beneficial for multiple reasons, including setting recovery expectations for the patient and demonstrating the effectiveness or success of the intervention.

METHODS

In this pilot study, we characterized a subset of patients (n = 82 from 7 surgeons) using a wearable sensor system at least 6 days before total knee arthroplasty and provided postsurgical data up to 50 days postintervention. The 5-day average before surgery for total step counts (activity), achieved flexion and extension on a progress test (functional limit) and visual analog scale daily pain score were calculated. The difference from baseline was then calculated for each patient for each day postsurgery and reported as averages.

RESULTS

On average, a patient will experience a relative deficit of 4,000 steps immediately following surgery that will return to near-baseline levels 50 days postintervention. A 30° deficit in flexion and a 10° deficit in extension will return at a similar rate as steps. Relative pain scores will worsen with an increase of approximately 3 points immediately following surgery. However, pain will decrease by 2 points relative to baseline between 40 and 50 days.

CONCLUSIONS

The results of this pilot study demonstrate a method to baseline a patient's presurgical subjective and objective data and to provide a reference for postsurgical recovery expectations. Applications for these data include benchmarking for evaluating intervention success as well as setting patient expectations.

Long-term outcomes after rehabilitation in Medicare Advantage and fee-for-service beneficiaries

BACKGROUND

Financial incentives in capitated Medicare Advantage (MA) plans may lead to inadequate rehabilitation. We therefore investigated if MA enrollees had worse long-term physical performance and functional outcomes after rehabilitation.

METHODS

We conducted a retrospective cohort study of Medicare beneficiaries in the nationally representative National Health and Aging Trends Study. We compared MA and fee-for-service (FFS) beneficiaries reporting rehabilitation between 2014 and 2017 by change in (1) Short Physical Performance Battery (SPPB) and (2) NHATS-derived Functional Independence Measure (FIM) from the previous year, using t-tests incorporating inverse-probability weighting and complex survey design. Secondary outcomes were self-reported: (1) improved function during rehabilitation, (2) worse function since rehabilitation ended, (3) meeting rehabilitation goals, and (4) meeting insurance limits.

RESULTS

Among 738 MA and 1488 FFS participants, weighted mean age was 76 years (SD 7.0), 59% were female, and 9% had probable dementia. MA beneficiaries were more likely to be Black (9% vs. 6%) or Hispanic/other race (15% vs. 10%), be on Medicaid (14% vs. 10%), have lower income (median $35,000 vs. $48,000), and receive <1 month of rehabilitation (30% vs. 23%). MA beneficiaries had a similar decline in SPPB (-0.46 [SD 1.8] vs. -0.21 [SD 2.7], p-value 0.069) and adapted FIM (-1.05 [SD 3.7] vs. -1.13 [SD 5.45], p-value 0.764) compared to FFS. MA beneficiaries were less likely to report improved function during rehabilitation (61% [95% CI 56-67] vs. 70% [95% CI 67-74], p-value 0.006). Other outcomes and analyses restricted to inpatient rehabilitation participants were non-significant.

CONCLUSIONS AND RELEVANCE

MA enrollment was associated with lower likelihood of self-reported functional improvement during rehabilitation but no clinically or statistically significant differences in annual changes of physical performance or function. As MA expands, future studies must monitor implications on rehabilitation coverage and older adults' independence.

Wearable sensor-based measures of step-up transfers are supplementary to patient-reported outcome measures following total joint arthroplasty

PURPOSE

This study investigated the longitudinal assessment of step-up performance in patients undergoing total joint arthroplasty (TJA) and correlation with subjective patient reported outcome measures (PROMs).

METHODS

In this sub-analysis of the ADAPT study, PROMs were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Block step-up (BS) transfers were assessed by wearable-derived measures of time. 76 patients undergoing TJA were included. Subgroups were formed isolating the worst performing quartile (low functioning (LF)) from the high functioning (HF), and outcomes were compared.

RESULTS

One-year post-surgery, WOMAC function demonstrated strong correlations to WOMAC pain (Pearson's r = 0.67-0.84) and moderate correlations to BS performance (Pearson's r = 0.31-0.54). Both WOMAC and BS significantly improved with a larger effect size for the HF subgroup (0.62 vs. 0.43; p < 0.05). Patients designated to the LF subgroup at 3 months had increased odds of representing the LF subgroup at 12 months (WOMAC = 19; BS = 4). WOMAC defined 18 LF patients at 12 months follow-up. BS performance identified 9 additional LF patients.

CONCLUSIONS

WOMAC function scores seem pain dominated. Measures of BS performance allow assessment of otherwise hidden residual functional impairment. Lower functioning 3 months post-surgery is predictive of longer-term impairment.

Maximal daily stepping cadence partially explains functional capacity of individuals with end-stage knee osteoarthritis

BACKGROUND

Individuals with end-stage knee osteoarthritis (OA) walk at a lower intensity (ie, slower step cadence) contributing to worse physical function. Previous literature reports daily step counts and sedentary time, with little information regarding stepping bouts or cadence. Determining relationships between daily higher stepping cadence duration and clinical outcomes can move the field toward optimal daily stepping prescription.

OBJECTIVE

To quantify daily physical activity patterns of individuals with end-stage knee OA and determine the contribution of high stepping cadence to explain functional capacity variability.

DESIGN

Cross-sectional analysis.

SETTING

Veterans Administration medical center.

PARTICIPANTS

U.S. military veterans (n = 104; age: 67.1 years [7.2]; mean [SD]; male [89.3%]) with end-stage knee OA were enrolled.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE

Functional capacity (6-Minute Walk Test [6MWT]). Physical activity (activPAL wearable sensor; cadence and time sitting, standing, and stepping), pain (Western Ontario and McMaster Universities Osteoarthritis Index-pain subscale) sociodemographic variables, and comorbidities (body mass index and Functional Comorbidity Index) are the main explanatory variables.

RESULTS

Participants' wake time was mainly sitting (11.0 h/day) in ≥60-minute bouts (29.7% ± 12.7 of sitting time). Standing (3.4 hours/day) and stepping (1.4 h/day) primarily occurred in 0-5 minute bouts (standing: 87.7% ± 14.4 of standing time, stepping: 98.7% ± 12.7 of stepping time) and stepping cadence was predominantly incidental (1-19 spm; 52.9% ± 9.6 of total stepping time). Backward elimination model results indicated shorter medium-to-brisk cadence bout duration, older age, and higher pain significantly explained shorter 6MWT distance (AdjR2=0.24, p < .01).

CONCLUSIONS

Individuals with knee OA spend most of their waking hours sitting, while standing and stepping occurs in short bouts at very low stepping cadence. Decreased time in high stepping cadence is associated with lower functional capacity. Future studies should explore if increasing the daily time spent in higher step cadence can improve functional capacity in this population.

Deficient gait function despite effect index of the Western Ontario and McMaster university osteoarthritis index score considered cured one year after bilateral total knee arthroplasty

BACKGROUND

To clarify the value of gait analysis and its consistency with traditional scoring scales for the evaluation of knee joint function after total knee arthroplasty (TKA).

METHODS

This study included 25 patients with knee osteoarthritis (KOA) who underwent bilateral TKA, and 25 conditionally matched healthy individuals, categorised into the experimental and control groups, respectively. Patients in the experimental group underwent gait analysis and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) evaluation before and 1 year after TKA. Weight-bearing balance and walking stability were assessed using discrete trends of relevant gait indicators. Pearson's correlation analysis was performed on the gait and WOMAC score data of the experimental group before and after TKA.

RESULTS

One year after TKA, patients' gait indices (except gait cycle) were significantly better than before surgery, but significantly worse than that of the control group (P < 0.01). The shape of patients' plantar pressure curves did not return to normal. Additionally, the discrete trend of related gait indicators reflecting weight-bearing balance and walking stability were smaller than before TKA, but still greater than that of the control group. The WOMAC scores of patients 1 year after TKA were significantly lower than those before TKA (P < 0.001), and the efficacy index was > 80%. The WOMAC scores and gait analysis results were significantly correlated before TKA (P < 0.05).

CONCLUSIONS

Gait analysis should be used in conjunction with scoring scales to assess joint functions.

The past and future of peri-operative interventions to reduce arthrogenic quadriceps muscle inhibition after total knee arthroplasty: A narrative review

Total knee arthroplasty (TKA) improves patient-reported function by alleviating joint pain, however the surgical trauma exacerbates already impaired muscle function, which leads to further muscle weakness and disability after surgery. This early postoperative strength loss indicates a massive neural inhibition and is primarily driven by a deficit in quadriceps muscle activation, a process known as arthrogenic muscle inhibition (AMI). To enhance acute recovery of quadriceps muscle function and long-term rehabilitation of individuals after TKA, AMI must be significantly reduced in the early post-operative period. The aim of this narrative review is to review and discuss previous efforts to mitigate AMI after TKA and to suggest new approaches and interventions for future efficacy evaluation. Several strategies have been explored to reduce the degree of post-operative quadriceps AMI and improve strength recovery after TKA by targeting post-operative swelling and inflammation or changing neural discharge. A challenge of this work is the ability to directly measure AMI and relevant contributing factors. For this review we focused on interventions that aimed to reduce post-operative swelling or improve knee extension strength or quadriceps muscle activation measured by twitch interpolation. For individuals undergoing TKA, the use of anti-inflammatory medications, tranexamic acid, cryotherapy, intra-articular drains, torniquets, and minimally invasive surgical techniques for TKA have limited benefit in attenuating quadriceps AMI early after surgery. However, interventions such as inelastic compression garments, voluntary muscle contractions, and neuro-muscular electrical stimulation show promise in mitigating or circumventing AMI and should continue to be refined and explored.

Predictors of physical activity recovery after total hip arthroplasty: a prospective observational study

PURPOSE

Little is known about the changes and the factors in physical activity as following total hip arthroplasty (THA). There are potential discrepancies between subjective and objective measurements of physical activity. Thus, our porpose is to compare objective and subjective measurements of activity levels in patients undergoing THA preoperatively, three months and one year following surgery, and investigated the factors that predicts the objective activity level after THA.

METHODS

This prospective observational study included 42 patients with unilateral symptomatic hip osteoarthritis who underwent THA. The objective activity level (step counts, sit-to-stands, and upright time) by using a tri-axial accelerometer, PRO (Oxford hip score; OHS and University of California, Los Angeles activity score; UCLA score), and muscle volume around the hip joint by using preoperative computed tomography were measured.

RESULTS

The number of steps, OHS, and UCLA score before, at three months, and one year after THA averaged 5092, 6532, and 6545 steps, 30.3, 43.0, and 44.2 points, and 3.4, 4.8, and 4.6 points, respectively, with significant postoperative increases (P < 0.05). No significant difference was found between three months and one year postoperatively. In multivariate analysis, younger age and higher preoperative contralateral gluteal medius volume were the predictors of higher postoperative step counts (P < 0.05).

CONCLUSIONS

Physical activity, including step counts, OHS, and UCLA score increased significantly until three months after unilateral THA. Early surgical intervention before contralateral muscle declines and preoperative rehabilitation including contralateral side may additionally improve postoperative activity levels.

Responsiveness of Isokinetic Dynamometry in Patients with Osteoarthritis after Knee and Hip Arthroplasty: A Prospective Repeated-Measures Cohort Study

Functional assessments are crucial for the evaluation of rehabilitation after total knee (TKA) and hip (THA) arthroplasty. Muscle strength, a key determinant of physical function (PF), is often measured with isokinetic dynamometry (ID), which is considered the gold standard. However, studies lack evaluations of responsiveness-the ability to detect changes over time. This study aims to determine the responsiveness of ID in measuring PF in TKA and THA rehabilitation-is muscle strength a valid indicator for assessing improvement in rehabilitation processes? The pre- and post-surgery PF of 20 osteoarthritis patients (age 55-82) was assessed, using ID, performance-based and self-reported measures. Responsiveness was evaluated by comparing the observed relationship of changes in ID and PF scores with the a priori defined expected relationship of change scores. While the performance-based and self-reported measures showed significant improvements post-surgery (Cohen's d [0.42, 1.05] p < 0.05), ID showed no significant differences. Moderate correlations were found between changes in some ID parameters and selected functional tests (r ≈|0.5|, p < 0.05). Responsiveness was solely found for the peak torque of knee extension at 180°/s on the operated side. Responsiveness is an often-overlooked psychometric property of outcome measurements. The findings suggest that ID may not be fully responsive to the construct of PF after TKA and THA, raising questions about its role and usefulness in this context and the need for more appropriate assessment methods.

Admission Cognition and Function Predict Change in Physical Function Following Skilled Nursing Rehabilitation

OBJECTIVES

Many older adults are discharged from skilled nursing facilities (SNFs) at functional levels below those needed for safe, independent home and community mobility. There is limited evidence explaining this insufficient recovery. The purpose of this secondary analysis was to determine predictors of physical function change following SNF rehabilitation.

DESIGN

Secondary analysis of a prospective observational cohort study.

SETTING AND PARTICIPANTS

Across 4 SNFs, data were collected from 698 adults admitted for physical rehabilitation following an acute hospitalization.

METHODS

Physical function recovery was evaluated as change from admission to discharge in Short Physical Performance Battery (SPPB) scores (N = 698) and gait speed (n = 444). Demographic and clinical characteristics collected at admission served as potential predictors of physical function change. Following imputation, a standardized model selection estimator was calculated for predictors per physical function outcome. Predictor estimates and 95% CIs were calculated for each outcome model.

RESULTS

Higher cognitive scores [standardized β (βSTD) = 0.11, 95% CI: 0.0004, 0.20] and higher activities of daily living (ADL) independence at admission (βSTD = 0.22, 95% CI: 0.05, 0.34) predicted greater SPPB change; higher SPPB scores at admission (βSTD = -0.26, 95% CI: -0.35, -0.14) predicted smaller SPPB change. Higher ADL independence at admission (βSTD = 0.17, 95% CI: 0.01, 0.37) predicted greater gait speed change; faster gait speed at admission (βSTD = -0.30, 95% CI: -0.44, -0.15) predicted smaller gait speed change.

CONCLUSIONS AND IMPLICATIONS

Admission cognition, ADL independence, and physical function predicted physical function change following post-hospitalization rehabilitation. Inverse findings for admission physical function and ADL independence predictors suggest independence with ADL is not necessarily aligned with mobility-related function. Findings highlight that functional recovery is multifactorial and requires comprehensive assessment throughout SNF rehabilitation.

Physical functioning in patients with end-stage knee osteoarthritis: A cross-sectional study in Jordan using self-reported questionnaire and performance-based tests

BACKGROUND

Knee osteoarthritis (OA) is a debilitating condition that leads to functional limitations. Self-reported questionnaires and performance-based tests are tools commonly used for measuring physical function.

OBJECTIVES

(1) To evaluate the impact of end-stage knee OA on functional outcomes and examine the association between self-reported and performance-based measures of function in patients with end-stage knee osteoarthritis awaiting total knee arthroplasty (2) To explore the interrelationships among pain, strength, and overall physical function in this patient population.

METHODS

In this cross-sectional analysis, 33 patients with end-stage knee OA were recruited and completed the knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and executed performance-based tests including the Timed Up and Go, the 30-second chair stand test, and the Stair Climbing Test. Knee pain, and isometric hip and knee strength were evaluated.

RESULTS

Patients perceived deficits in their physical functionwith a score of 35/100 on the KOS-ADLS and demonstrated functional limitations in all performed tasks. KOS-ADLs was weakly associated with TUG and 30s-CST (r=-0.301, p= 0.047, and r= 0.39, p= 0.014. respectively). Knee pain was linked with the KOS-ADL score and GRS score (r=-0.406, p= 0.010; r=-0.343, p= 0.027; respectively), while the strength of the affected side was correlated with the performed (p=< 0.001) and reported function outcomes (p= 0.007).

CONCLUSION

Participants exhibit declines in both perceived and executed functional abilities. Self-reported and performance-based functional measures are weakly correlated within our study group, highlighting the importance of incorporating both measures in clinical practice for a comprehensive evaluation of physical function. Pain was linked to subjective aspect of physical function, while strength was connected to perceived and performed functional capacity. Implementing a tailored rehabilitation program targeting muscle weakness and pain holds the potential to mitigate functional decline in individuals awaiting total knee arthroplasty (TKA).

Increase in the Initial Outpatient Rehabilitation Utilization for Patients With Total Knee Arthroplasty

OBJECTIVES

The objective of this study was to examine the patient characteristics and features associated with the initial rehabilitation utilization with a particular emphasis on outpatient rehabilitation after total knee arthroplasty (TKA) among 2016-2018 Texas Medicare enrollees.

DESIGN

This is a retrospective cohort study. We used chi-square tests to examine the variability in patient demographic and clinical characteristics across the different post-acute rehabilitation settings after TKA. A Cochran-Armitage trend test was used to investigate the yearly trend of outpatient rehabilitation utilization after TKA.

SETTING

Post-acute rehabilitation settings after TKA.

PARTICIPANTS

The target population was Medicare beneficiaries aged ≥65 with an initial TKA in 2016-2018 and complete demographic and residential information (N=44,313).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We identified whether patients first used (1) outpatient rehabilitation, (2) home health, (3) self-care, (4) inpatient rehabilitation, (5) skilled nursing, or (6) other setting within the 3 months after TKA.

RESULTS

Our results demonstrated an increasing use of the initial outpatient rehabilitation and home health, while the use of skilled nursing and inpatient rehabilitation facilities decreased from 2016 to 2018. The increase in outpatient utilization was significant in 2018 compared with 2016 controlling for distance to the TKA facilities, comorbid conditions, sex, race/ethnicity groups (White, Black, Hispanic, and Others), lower income (Medicaid eligible), Medicare entitlement types, age groups, and rurality (OR 1.23, 95% CI 1.12-1.34). However, the overall utilization rate of the initial outpatient rehabilitation after TKA remained low, increasing from 7.36% in 2016 to 8.60% in 2018.

CONCLUSION

Despite the growing use of the initial outpatient rehabilitation after TKA, the overall rate of outpatient rehabilitation utilization remained low. Our findings raise an important question as to whether certain patient demographics and clinical groups might have limited access to outpatient rehabilitation after TKA.

Comparison of Dynamic Knee Contact Mechanics with T2 Imaging in Different Ages of Healthy Participants

Aging is a known risk factor for Osteoarthritis (OA), however, relations between cartilage composition and aging remain largely unknown in understanding human OA. T2 imaging provides an approach to assess cartilage composition. Whether these T2 relaxation times in the joint contact region change with time during gait remain unexplored. The study purpose was to demonstrate a methodology for linking dynamic joint contact mechanics to cartilage composition as measured by T2 relaxometry. T2 relaxation times for unloaded cartilage were measured in a 3T General Electric magnetic resonance (MR) scanner in this preliminary study. High-speed biplanar video-radiography (HSBV) was captured for five 20-30-year-old and five 50-60-year-old participants with asymptomatic knees. By mapping the T2 cartilages to the dynamic contact regions, T2 values were averaged over the contact area at each measurement within the gait cycle. T2 values demonstrated a functional relationship across the gait cycle. There were no statistically significant differences between 20- and 30-year-old and 50-60-year-old participant T2 values at first force peak of the gait cycle in the medial femur (p = 1.00, U = 12) or in the medial tibia (p = 0.31, U = 7). In the medial and lateral femur in swing phase, the joint moved from a region of high T2 values at 75% of gait to a minimum at 85-95% of swing. The lateral femur and tibia demonstrated similar patterns to the medial compartments but were less pronounced. This research advances understanding of the linkage between cartilage contact and cartilage composition. The change from a high T2 value at ~ 75% of gait to a lower value near the initiation of terminal swing (90% gait) indicates that there are changes to T2 averages corresponding to changes in the contact region across the gait cycle. No differences were found between age groups for healthy participants. These preliminary findings provide interesting insights into the cartilage composition corresponding to dynamic cyclic motion and inform mechanisms of osteoarthritis.

Advances in the application of wearable sensors for gait analysis after total knee arthroplasty: a systematic review

BACKGROUND

Wearable sensors have become a complementary means for evaluation of body function and gait in lower limb osteoarthritis. This study aimed to review the applications of wearable sensors for gait analysis after total knee arthroplasty (TKA).

METHODS

Five databases, including Web of Science Core Collection, Embase, Cochrane, Medline, and PubMed, were searched for articles published between January 2010 and March 2023, using predetermined search terms that focused on wearable sensors, TKA, and gait analysis as broad areas of interest.

RESULTS

A total of 25 articles were identified, involving 823 TKA patients. Methodologies varied widely across the articles, with inconsistencies found in reported patient characteristics, sensor data and experimental protocols. Patient-reported outcome measures (PROMs) and gait variables showed various recovery times from 1 week postoperatively to 5 years postoperatively. Gait analysis using wearable sensors and PROMs showed differences in controlled environments, daily life, and when comparing different surgeries.

CONCLUSION

Wearable sensors offered the potential to remotely monitor the gait function post-TKA in both controlled environments and patients' daily life, and covered more aspects than PROMs. More cohort longitudinal studies are warranted to further confirm the benefits of this remote technology in clinical practice.

Prognostic factors of knee pain and function 12 months after total knee arthroplasty: A prospective cohort study of 798 patients

BACKGROUND

Approximately 20% of patients undergoing total knee arthroplasty (TKA) do not experience long-term improvements. Our aim was to identify prognostic factors of knee pain and function 12 months after TKA.

METHODS

In a prospective cohort study, 1026 patients underwent primary TKA between 2018 and 2020. Main outcome was measured by the Oxford Knee Score (OKS) categorized in five categories (0-9, 10-19, 20-29, 30-39 and 40-48). Potential prognostic factors obtained at baseline included sex, age, baseline OKS, pain catastrophizing scale, EuroQol 5 dimensions, previous surgery, BMI, ASA classification, opioid consumption, living and employment conditions as well as educational level. Ordinal logistic regression analysis was used to identify prognostic factors of OKS.

RESULTS

A total of 915 patients completed follow up (89%), and patients with complete data were included (n = 798). Patients with a baseline OKS between 10-19 and 20-29 had 2.5 (CI 1.6;4.0) and 1.6 (CI 1.1;2.4) higher odds, respectively, of no improvement or deterioration to a lower post-operative OKS category, compared with patients with a baseline score between 30 and 39. Female patients had 1.5 (CI 1.1;2.0) and patients receiving social benefits compared with retired patients had 2.0 (CI 1.1;3.5) higher odds of no improvement or deterioration to a lower OKS category.

CONCLUSION

Baseline level of pain and function, sex and employment status were significant prognostic factors of OKS 12 months after TKA. Overall, the regression analysis only explained 4% of the outcome, indicating that it is difficult to predict 12-month TKA outcome prior to surgery.

Relationships between self-perceived and clinical expression of pain and function differ based on the underlying pathology of the human hip

BACKGROUND

Patient-reported outcomes are commonly used to assess patient symptoms. The effect of specific hip pathology on relationships between perceived and objectively measured symptoms remains unclear. The purpose of this study was to evaluate differences of function and pain in patients with FAIS and DDH, to assess the correlation between perceived and objective function, and to determine the influence of pain on measures of function.

METHODS

This prospective cross-sectional study included 35 pre-operative patients (60% female) with femoroacetabular impingement syndrome (FAIS) and 37 pre-operative patients (92% female) with developmental dysplasia of the hip (DDH). Objectively measured function (6-min walk [6MWT], single leg hop [SLHT], Biodex sway [BST], hip abduction strength [HABST], and STAR excursion balance reach [STAR] tests), patient-reported function (UCLA Activity, Hip Outcome Score [HOS], Short Form 12 [SF-12], and Hip Disability and Osteoarthritis Outcome Score [HOOS]), and patient-reported pain (HOOS Pain, visual analogue scale (VAS), and a pain location scale) were collected during a pre-surgical clinic visit. Between-group comparisons of patient scores were performed using Wilcoxon Rank-Sum tests. Within-group correlations were analyzed using Spearman's rank correlation coefficients. Statistical correlation strength was defined as low (r =  ± 0.1-0.3), moderate (r =  ± 0.3-0.5) and strong (r >  ± 0.5).

RESULTS

Patients with DDH reported greater pain and lower function compared to patients with FAIS. 6MWT distance was moderately-to-strongly correlated with a number of patient-reported measures of function (FAIS: r = 0.37 to 0.62, DDH: r = 0.36 to 0.55). Additionally, in patients with DDH, SLHT distance was well correlated with patient reported function (r = 0.37 to 0.60). Correlations between patient-reported pain and objectively measured function were sparse in both patient groups. In patients with FAIS, only 6MWT distance and HOOS Pain (r = -0.53) were significantly correlated. In patients with DDH, 6MWT distance was significantly correlated with VAS Average (r = -0.52) and Best (r = -0.53) pain.

CONCLUSION

Pain is greater and function is lower in patients with DDH compared to patients with FAIS. Moreover, the relationship between pain and function differs between patient groups. Understanding these differences is valuable for informing treatment decisions. We recommend these insights be incorporated within the clinical continuum of care, particularly during evaluation and selection of surgical and therapeutic interventions.

Stepping Beyond Counts in Recovery of Total Hip Arthroplasty: A Prospective Study on Passively Collected Gait Metrics

Gait quality parameters have been used to measure recovery from total hip arthroplasty (THA) but are time-intensive and previously could only be performed in a lab. Smartphone sensor data and algorithmic advances presently allow for the passive collection of qualitative gait metrics. The purpose of this prospective study was to observe the recovery of physical function following THA by assessing passively collected pre- and post-operative gait quality metrics. This was a multicenter, prospective cohort study. From six weeks pre-operative through to a minimum 24 weeks post-operative, 612 patients used a digital care management application that collected gait metrics. Average weekly walking speed, step length, timing asymmetry, and double limb support percentage pre- and post-operative values were compared with a paired-sample t-test. Recovery was defined as the post-operative week when the respective gait metric was no longer statistically inferior to the pre-operative value. To control for multiple comparison error, significance was set at p < 0.002. Walking speeds and step length were lowest, and timing asymmetry and double support percentage were greatest at week two post-post-operative (p < 0.001). Walking speed (1.00 ± 0.14 m/s, p = 0.04), step length (0.58 ± 0.06 m/s, p = 0.02), asymmetry (14.5 ± 19.4%, p = 0.046), and double support percentage (31.6 ± 1.5%, p = 0.0089) recovered at 9, 8, 7, and 10 weeks post-operative, respectively. Walking speed, step length, asymmetry, and double support all recovered beyond pre-operative values at 13, 17, 10, and 18 weeks, respectively (p < 0.002). Functional recovery following THA can be measured via passively collected gait quality metrics using a digital care management platform. The data suggest that metrics of gait quality are most negatively affected two weeks post-operative; recovery to pre-operative levels occurs at approximately 10 weeks following primary THA, and follows a slower trajectory compared to previously reported step count recovery trajectories.

Assessment of Pain in Osteoarthritis of the Knee

Knee osteoarthritis (KOA) pain is a subjective and personal experience, making it challenging to characterise patients' experiences and assess their pain. In addition, there is no global standard for the assessment of pain in KOA. Therefore, this article examines the possible methods of assessing and characterising pain in patients with KOA using clinical symptoms, pain assessment tools, and imaging. We examine the current methods of assessment of pain in KOA and their application in clinical practice and clinical trials. Furthermore, we explore the possibility of creating individualised pain management plans to focus on different pain characteristics. With better evaluation and standardisation of pain assessment in these patients, it is hoped that patients would benefit from improved quality of life. At the same time, improvement in pain assessment would enable better data collection regarding symptom response in clinical trials for the treatment of osteoarthritis.

Impact of end-stage knee osteoarthritis on perceived physical function and quality of life: A descriptive study from Jordan

OBJECTIVE

Of the present study was to evaluate the impact of end-stage knee OA on patient's perception of their functional abilities and quality of life (QoL) using the self-reported questionnaire; the Knee Injury and Osteoarthritis Outcome Score (KOOS), and to determine the contribution of knee pain on patient's perceived outcomes.

METHODS

Patients with end-stage knee OA who are on the waiting list for total knee arthroplasty were recruited in this cross-sectional study. Patients were asked to fill out the KOOS questionnaire. Knee pain for both sides was quantified on a continuous scale from 0-10. Age, and anthropometric data were recorded. Descriptive statistics were calculated for patients' characteristics, and for the scores of each KOOS subscale. Hierarchical linear regression models were created to determine the contributions of knee pain on two KOOS subscales; the function in daily living (KOOS-ADL), and the knee-related quality of life (KOOS-QoL).

RESULTS

Patients in this study scored low across KOOS subscales (27.7% - 54.2%) with the QoL subscale being the lowest. After accounting for age and BMI, hierarchical linear regressions revealed that knee pain in both sides were determinants of self-perceived KOOS-ADLs, while only knee pain in the most-affected side significantly contributed to lower KOOS-QOL scores.

CONCLUSION

End-stage knee OA negatively impact the patients' perceived function and quality of life. Patients' KOOS scores were similar to those reported in other countries, with QoL being the domain most affected. Our findings demonstrate that the level of knee pain has a determinant effect on our patients' perceptions of functional abilities and QoL. As waiting-list patients, addressing knee pain with a targeted regimen prior to TKA, as well as increasing patient's awareness about knee pain management, may improve/ or minimize deterioration in perceived functional ability and QoL while awaiting TKA.

Objective performance tests assess aspects of function not captured by self-report in knee osteoarthritis

Objective

Knee osteoarthritis (OA) can substantially limit function, which can be assessed both objectively and subjectively. We examined whether objective performance tests are associated with self-reported function.

Methods

We analyzed baseline data from the Osteoarthritis Registry of Biomarker and Imaging Trajectories (ORBIT) of participants ≥40 years old with symptomatic and radiographic knee OA. Subjects completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain and Activities of Daily Living (ADL) scales and other assessments of pain and comorbidity. Subjects performed the timed single leg balance test (SLB), 30-s sit-to-stand (30s STS), Timed-Up-and-Go (TUG), and 40-m fast paced walk (40 ​m Walk). We used Pearson correlation coefficients to examine associations between performance and KOOS subscales. We adjusted for potential confounders using partial correlations.

Results

We enrolled 101 subjects (mean age 63.7 (standard deviation (SD) 10.1), mean BMI 30.0 (SD 5.6), and 63% female). The mean (SD) values for the performance tests were: SLB 20.1 (18.9) seconds, 30s STS 11.7 (4.6) stands, TUG 9.4 (2.3) seconds, and 40 ​m Walk 27.6 (6.5) seconds. Correlations between performance tests and self-report measures did not exceed 0.39, with the absolute value of correlations between KOOS ADL and performance measures ranging from 0.24 to 0.39. Adjusted partial correlations were largely similar to the crude correlations.

Conclusions

Self-reported function in persons with knee OA had weak to modest correlations with objective function. Objective performance tests capture elements of physical function that self-report data do not and point to the potential value of including objective measures of functional status in OA trials.

Mitochondrial function, grip strength, and activity are related to recovery of mobility after a total knee arthroplasty

Low muscle quality and a sedentary lifestyle are indicators for a slow recovery after a total knee arthroplasty (TKA). Mitochondrial function is an important part of muscle quality and a key driver of sarcopenia. However, it is not known whether it relates to recovery. In this pilot study, we monitored activity after TKA using a wrist mounted activity tracker and assessed the relation of mitochondrial function on the rate of recovery after TKA. Additionally, we compared the increase in activity as a way to measure recovery to traditional outcome measures. Patients were studied 2 weeks before TKA and up to 6 months after. Activity was monitored continuously. Baseline mitochondrial function (citrate synthase and complex [CP] 1-5 abundance of the electron transport chain) was determined on muscle tissue taken during TKA. Traditional outcome measures (Knee Injury and Osteoarthritis Outcome Score [KOOS], timed up-and-go [TUG] completion time, grip, and quadriceps strength) were performed 2 weeks before, 6 weeks after, and 6 months after TKA. Using a multivariate regression model with various clinical baseline parameters, the following were significantly related to recovery: CP5 abundance, grip strength, and activity (regression weights 0.13, 0.02, and 2.89, respectively). During recovery, activity correlated to the KOOS-activities of daily living (ADL) score (r = 0.55, p = 0.009) and TUG completion time (r = -0.61, p = 0.001). Mitochondrial function seems to be related to recovery, but so are activity and grip strength, all indicators of sarcopenia. Using activity trackers before and after TKA might give the surgeon valuable information on the expected recovery and the opportunity to intervene if recovery is low.

Test-retest reliability of the L-Test in patients with advanced knee osteoarthritis

BACKGROUND

The reliability of tests to be used in research or clinical practice should be established for each population specific to their intended use. Reliability is important because it allows correct evaluations to be made about treatment effects or about the amount of changes.

OBJECTIVES

To evaluate the test-retest reliability and minimal detectable change of the L-test in patients with advanced knee osteoarthritis (OA).

METHODS

The intraclass correlation coefficient (ICC2,1) was used to assess the test-retest reliability of the L-test. The minimal detectable change with 95% confidence interval (MDC95) was calculated to determine the true change. The inclusion criteria were diagnosis of knee OA, had Kellgren Lawrence Grade IV and age of ≥40 years.

RESULTS

Twenty-five participants who met the inclusion criteria were included. Five were male and the mean age was 62.32±9.77 years. All of the participants had radiographic findings indicative of Kellgren-Lawrence Grade IV. The L-test showed excellent test-retest reliability. The ICC was 0.99, the SEM and the MDC95 was 1,90 and 5.28 seconds, respectively.

CONCLUSIONS

The L-test is a reliable outcome measurement for the assessment of walking ability in patients with advanced knee OA, and it showed very high test-retest reliability in these patients. This test may assist clinicians and researchers in assessing the functional mobility of patients and planning rehabilitation in patients with advanced knee OA.

Objective gait assessment in individuals with knee osteoarthritis using inertial sensors: A systematic review and meta-analysis

BACKGROUND

Objective assessment of gait using inertial sensors has shown promising results for functional evaluations in individuals with knee osteoarthritis (OA). However, the large number of possible outcome measures calls for a systematic evaluation of most relevant parameters to be used for scientific and clinical purposes.

AIM

This systematic review and meta-analysis aimed to identify gait parameters derived from inertial sensors that reflect gait deviations in individuals with knee OA compared to healthy control subjects (HC).

METHODS

A systematic search was conducted in five electronic databases (Medline, Embase, Web of Science, CINAHL, IEEE) to identify eligible articles. Risk of bias was assessed using a modified version of the Downs and Black scale. Data regarding study population, experimental procedures, and biomechanical outcomes were extracted. When a gait parameter was reported by a sufficient number of studies, a random-effects meta-analysis was conducted using the inverse variance method.

RESULTS

Twenty-three articles comparing gait between 411 individuals with knee OA and 507 HC were included. Individuals with knee OA had a lower gait speed than HC (standardized mean difference = -1.65), driven by smaller strides with a longer duration. Stride time variability was slightly higher in individuals with knee OA than in HC. Individuals with knee OA walked with a lower range of motion of the knee during the swing phase, less lumbar motion in the coronal plane, and a lower foot strike and toe-off angle compared to HC.

SIGNIFICANCE

This review shows that inertial sensors can detect gait impairments in individuals with knee OA. Large standardized mean differences found on spatiotemporal parameters support their applicability as sensitive endpoints for mobility in individuals with knee OA. More advanced measures, including kinematics of knee and trunk, may reveal gait adaptations that are more specific to knee OA, but compelling evidence was lacking.

Integrating wearables and modelling for monitoring rehabilitation following total knee joint replacement

BACKGROUND AND OBJECTIVE

Wearable inertial devices integrated with modelling and cloud computing have been widely adopted in the sports sector, however, their use in the health and medical field has yet to be fully realised. To date, there have been no reported studies concerning the use of wearables as a surrogate tool to monitor knee joint loading during recovery following a total knee joint replacement. The objective of this study is to firstly evaluate if peak tibial acceleration from wearables during gait is a good surrogate metric for computer modelling predicted functional knee loading; and secondly evaluate if traditional clinical patient related outcomes measures are consistent with wearable predictions.

METHODS

Following ethical approval, four healthy participants were used to establish the relationship between computer modelling predicted knee joint loading and wearable measured tibial acceleration. Following this, ten patients who had total knee joint replacements were then followed during their 6-week rehabilitation. Gait analysis, wearable acceleration, computer models of knee joint loading, and patient related outcomes measures including the Oxford knee score and range of motion were recorded.

RESULTS

A linear correlation (R² of 0.7-0.97) was observed between peak tibial acceleration (from wearables) and musculoskeletal model predicted knee joint loading during gait in healthy participants first. Whilst patient related outcome measures (Oxford knee score and patient range of motion) were observed to improve consistently during rehabilitation, this was not consistent with all patient's tibial acceleration. Only those patients that exhibited increasing peak tibial acceleration over 6-weeks rehabilitation were positively correlated with the Oxford knee score (R² of 0.51 to 0.97). Wearable predicted tibial acceleration revealed three patients with a consistent knee loading, five patients with improving knee loading, and two patients with declining knee loading during recovery. Hence, 20% of patients did not present with satisfactory joint loading following total knee joint replacement and this was not detected with current patient related outcome measures.

CONCLUSIONS

The use of inertial measurement units or wearables in this study provided additional insight into patients who were not exhibiting functional improvements in joint loading, and offers clinicians an 'off-site' early warning metric to identify potential complications during recovery and provide the opportunity for early intervention. This study has important implications for improving patient outcomes, equity, and for those who live in rural regions.

Objective monitoring of functional recovery after total knee and hip arthroplasty using sensor-derived gait measures

Background

Inertial sensors hold the promise to objectively measure functional recovery after total knee (TKA) and hip arthroplasty (THA), but their value in addition to patient-reported outcome measures (PROMs) has yet to be demonstrated. This study investigated recovery of gait after TKA and THA using inertial sensors, and compared results to recovery of self-reported scores of pain and function.

Methods

PROMs and gait parameters were assessed before and at two and fifteen months after TKA (n = 24) and THA (n = 24). Gait parameters were compared with healthy individuals (n = 27) of similar age. Gait data were collected using inertial sensors on the feet, lower back, and trunk. Participants walked for two minutes back and forth over a 6m walkway with 180° turns. PROMs were obtained using the Knee Injury and Osteoarthritis Outcome Scores and Hip Disability and Osteoarthritis Outcome Score.

Results

Gait parameters recovered to the level of healthy controls after both TKA and THA. Early improvements were found in gait-related trunk kinematics, while spatiotemporal gait parameters mainly improved between two and fifteen months after TKA and THA. Compared to the large and early improvements found in of PROMs, these gait parameters showed a different trajectory, with a marked discordance between the outcome of both methods at two months post-operatively.

Conclusion

Sensor-derived gait parameters were responsive to TKA and THA, showing different recovery trajectories for spatiotemporal gait parameters and gait-related trunk kinematics. Fifteen months after TKA and THA, there were no remaining gait differences with respect to healthy controls. Given the discordance in recovery trajectories between gait parameters and PROMs, sensor-derived gait parameters seem to carry relevant information for evaluation of physical function that is not captured by self-reported scores.

Measurement properties of performance-based measures to assess physical function in knee osteoarthritis: A systematic review

OBJECTIVE

To systematically review the measurement properties of performance-based measures to assess physical function in people with knee osteoarthritis.

DATA SOURCES

PubMed, Web of Science, Embase, Scopus, CINAHL, and PsycINFO were searched in May 2022.

METHODS

This study was conducted in accordance with the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Clinical trials on the psychometric properties of performance-based tools for measuring physical function in people with knee osteoarthritis were included. Two reviewers independently rated measurement properties using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). "Best evidence synthesis" was made using COnsensus-based Standards for the selection of health Measurement INstruments outcomes and the quality of findings.

RESULTS

Thirty-six out of 3425 publications were eligible for inclusion. Thirty-two performance-based measures were evaluated including 26 single-activity measures and 6 multi-activity measures. Measurement properties evaluated included internal consistency (2 measures), reliability (23 measures), measurement error (20 measures), hypotheses testing for construct validity (22 measures), and responsiveness (23 measures). On balance of the limited evidence, the walk 40 m fast-paced test and 6-minute walking test were the best rated walking tests. The 30-second chair stand test and timed up and go test were the best rated sit-to-stand tests. The Performance Tests Measures and Physical Activity Restrictions may be the suitable multi-activity measures for knee osteoarthritis.

CONCLUSIONS

Further good quality research investigating the measurement properties, and in particular, the measurement error of performance-based measures in patients with knee osteoarthritis is needed.

Can Patient-Reported Outcome Measurement Information System Measures Differentiate Patients Who Will Undergo Hip and Knee Total Joint Arthroplasty: A Retrospective Case-Control Study

BACKGROUND

The Patient-Reported Outcome Measurement Information System (PROMIS) can be used to monitor patients in population-health-based programs. However, it is unknown which measures are most appropriate to differentiate patients who will undergo hip or knee total joint arthroplasty (TJA) in a cohort of patients with osteoarthritis.

METHODS

A retrospective cohort of new patients consulting for treatment from November 17, 2017 to April 20, 2020 (cases: hip: n = 157, knee: n = 112; randomly selected nonsurgical controls: hip: n = 314, knee: n = 224) was extracted from the electronic health record. We recorded demographics, comorbidity, and PROMIS scores for 8 domains (physical function, pain interference, pain intensity, anxiety, depression, sleep disturbance, ability to participate in social roles and activities, and fatigue). We performed descriptive statistics to characterize the cohorts and baseline PROMIS scores and conducted logistic regression models to determine which PROMIS domains differentiated patients undergoing hip and knee TJA.

RESULTS

In univariate comparisons of PROMIS domains, the hip and knee surgical cohorts differed from controls in physical function (P < .01), pain interference (P < .01), and ability to participate in social roles and activities (P < .02). In logistic regression models informed by univariate analyses, PROMIS physical function was the only PROMIS measure to differentiate undergoing surgery in both hip and knee cohorts (P < .01).

CONCLUSION

PROMIS physical function can differentiate TJA cases from nonsurgical controls in both hip and knee patients. These findings have implications for considering which PROMIS measures to administer in patients with hip and knee osteoarthritis.

Total Knee Arthroplasty Assessments Should Include Strength and Performance-Based Functional Tests to Complement Range-of-Motion and Patient-Reported Outcome Measures

Range of motion (ROM) and pain often define successful recovery after total knee arthroplasty (TKA), but these routine clinical outcomes correlate poorly or not at all to functional capacity after TKA. The purpose of this Perspective is to underscore the importance of muscle strength and performance-based functional tests in addition to knee ROM and patient-reported outcome (PRO) measures to evaluate outcomes after TKA. Specifically: (1) muscle strength is the rate-limiting step for recovery of function after TKA; (2) progressive rehabilitation targeting early quadriceps muscle strengthening improves outcomes and does not compromise ROM after TKA; (3) ROM and PROs fail to fully capture functional limitations after TKA; and (4) performance-based functional tests are critical to evaluate function objectively after TKA. This Perspective also addresses studies that question the need for or benefit of physical therapy after TKA because their conclusions focus only on ROM and PRO measures. Future research is needed to determine the optimal timing, delivery, intensity, and content of physical therapy.

GaitSmart motion analysis compared to commonly used function outcome measures in the IMI-APPROACH knee osteoarthritis cohort

Background

There are multiple measures for assessment of physical function in knee osteoarthritis (OA), but each has its strengths and limitations. The GaitSmart® system, which uses inertial measurement units (IMUs), might be a user-friendly and objective method to assess function. This study evaluates the validity and responsiveness of GaitSmart® motion analysis as a function measurement in knee OA and compares this to Knee Injury and Osteoarthritis Outcome Score (KOOS), Short Form 36 Health Survey (SF-36), 30s chair stand test, and 40m self-paced walk test.

Methods

The 2-year Innovative Medicines Initiative—Applied Public-Private Research enabling OsteoArthritis Clinical Headway (IMI-APPROACH) knee OA cohort was conducted between January 2018 and April 2021. For this study, available baseline and 6 months follow-up data (n = 262) was used. Principal component analysis was used to investigate whether above mentioned function instruments could represent one or more function domains. Subsequently, linear regression was used to explore the association between GaitSmart® parameters and those function domains. In addition, standardized response means, effect sizes and t-tests were calculated to evaluate the ability of GaitSmart® to differentiate between good and poor general health (based on SF-36). Lastly, the responsiveness of GaitSmart® to detect changes in function was determined.

Results

KOOS, SF-36, 30s chair test and 40m self-paced walk test were first combined into one function domain (total function). Thereafter, two function domains were substracted related to either performance based (objective function) or self-reported (subjective function) function. Linear regression resulted in the highest R² for the total function domain: 0.314 (R² for objective and subjective function were 0.252 and 0.142, respectively.). Furthermore, GaitSmart® was able to distinguish a difference in general health status, and is responsive to changes in the different aspects of objective function (Standardized response mean (SRMs) up to 0.74).

Conclusion

GaitSmart® analysis can reflect performance based and self-reported function and may be of value in the evaluation of function in knee OA. Future studies are warranted to validate whether GaitSmart® can be used as clinical outcome measure in OA research and clinical practice.

Patients' perceived walking abilities, daily-life gait behavior and gait quality before and 3 months after total knee arthroplasty

INTRODUCTION

Functional outcome and patients' daily-life activities after total knee arthroplasty are becoming more important with a younger and more active patient population. In addition to patient-reported outcome measures (PROMs), trunk-based accelerometry has shown to be a promising method for evaluating gait function after total knee arthroplasty. The aim of this study was to evaluate daily-life perceived walking abilities, gait behavior and gait quality before and 3 months after total knee arthroplasty, using PROMs and trunk-based accelerometry.

MATERIALS AND METHODS

A cohort of 38 patients completed questionnaires including the Oxford Knee Score and modified Gait Efficacy Scale before and 3 months after primary unilateral total knee arthroplasty. At both time points, they wore a tri-axial accelerometer at the lower back for seven consecutive days and nights. Gait behavior was calculated using gait quantity and walking speed, and multiple gait quality parameters were calculated.

RESULTS

Significant improvements were seen after 3 months in the Oxford Knee Score [median (interquartile range) 29 (10) vs 39 (8), p < 0.001] and modified Gait Efficacy Scale [median (interquartile range) 67 (24) vs 79 (25), p = 0.001]. No significant changes were observed in gait behavior (quantity and speed) or gait quality variables.

CONCLUSIONS

In contrast to the significant improvements in patients' perception of their walking abilities and PROMs, patients did not show improvements in gait behavior and gait quality. This implies that after 3 months patients' perceived functional abilities after total knee arthroplasty do not necessarily represent their actual daily-life quantity and quality of gait, and that more focus is needed on postoperative rehabilitation to improve gait and functional behavior.

The effect of restored medial knee anatomy in total knee arthroplasty with the flexion first balancer technique on mid-flexion laxity and functional outcome

Background

The Flexion First Balancer (FFB) technique for total knee arthroplasty (TKA) was developed to maintain the isometry of the medial collateral ligament (MCL) by restoring the medial anatomy of the knee. Inability to correct MCL isometry could hypothetically result in an increased mid-flexion laxity. The aim of the current study was to evaluate if the FFB technique results in improved functional outcome and less mid-flexion laxity compared to Measured Resection (MR).

Methods

A cross-sectional study was performed comparing 27 FFB patients with 28 MR patients. Groups were matched for age, gender, BMI and ASA classification. All patient received the cruciate retained type, Vanguard Complete Knee System (Biomet Orthopedics, Warsaw, IN, USA). Stress X-rays of the knee with 30 degrees of flexion were made to assess varus-valgus laxity. Furthermore, three tests were conducted to asses functional outcome: a 6 min walk test, a stair climb test and quadriceps peak force measurements. Mean follow-up was respectively 2.6 (SD 0.4) and 3.9 years (SD 0.2).

Results

The MR group showed a postoperative elevation in joint line in contrast to the FFB group, the mean difference between the two groups was 3 mm (p < 0.001). No differences in total laxity between the two groups was found. The FFB group showed a higher quadriceps peak force (1.67 (SD 0.55) N/BMI) in comparison with the MR group (1.38 (SD 0.48) N/BMI) (p < 0.05). All other outcome parameters were comparable between the two groups (p: n.s.). Correlation analysis showed a moderate negative correlation between joint line elevation and quadriceps peak force (r = − 0.29, p < 0.05).

Conclusion

The FFB technique did not lead to less coronal laxity in the mid-flexion range compared to MR. Although peak quadriceps force was significantly higher for the FFB group no clinically relevant benefits could be identified for the patients with regards to functional outcome. Therefore, minor deviations in joint line seems to have no effect on functional outcome after TKA.

Trial registration

ISRCTN, ISRCTN85351296. Registered 23 april 2021 - Retrospectively registered, https://www.isrctn.com/ISRCTN85351296

Reliability, validity and responsiveness of the Step Up and Down (StUD) test for individuals with symptomatic knee osteoarthritis

BACKGROUND

Stair climbing test (SCT) has been suggested as the first task affected in individuals with symptomatic knee osteoarthritis (KOA). However, there are environmental barriers for the execution of the 9- to 12-step SCT. Thus, we developed a feasible one-step SCT that could be completed in 15s.

OBJECTIVE

To check the clinimetric properties of the 15s Step Up and Down (StUD) test in individuals with KOA.

DESIGN

Prospective validity study.

METHOD

Eighty-two individuals with KOA participated in this study. The test-retest reliability of the StUD test was measured with a 1-week interval. The construct validity and responsiveness were assessed by testing predefined hypotheses. For this, the 30s Chair Stand Test (30CS), Timed Up and Go Test (TUG), quadriceps strength, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lequesne Algofunctional Index were used as comparator instruments.

RESULTS

The StUD test presented good test-retest reliability (ICC = 0.87; 95% CI = 0.79-0.91) and showed a moderate to good correlation with the 30CS (r = 0.65), TUG (r = -0.56), and quadriceps strength (r = 0.41). We found a higher correlation between the StUD test and the performance-based tests than the patient-reported outcome measures. The StUD test was responsive, with five out of the six (83.3%) hypotheses confirmed.

CONCLUSION

StUD test showed good reliability, adequate validity and responsiveness. Our findings suggest that StUD is a useful performance-based test for individuals with KOA.

Self-Reported and Performance-Based Evaluations of Functional Status in Older Women With Breast Cancer

OBJECTIVES

To evaluate self-reported and performance-based functional status (FS) in older women with breast cancer according to stage and time of visit during treatment.

SAMPLE & SETTING

72 women with breast cancer aged 78 years or older and receiving any type of treatment at a midwestern outpatient clinic.

METHODS & VARIABLES

FS was evaluated using grip strength, the Index of Activities of Daily Living (ADLs), the instrumental ADLs (IADLs) scale, and the Timed Up and Go Test (TUGT). Mixed models were fit for grip strength and the TUGT, and generalized estimating equations were used to fit binary logistic regressions for the Index of ADLs and the IADLs scale. Continuous FS outcomes were evaluated using means and standard deviations.

RESULTS

Cancer stage and time of visit did not affect self-reported or performance-based FS scores. Most participants were considered independent on the Index of ADLs, the IADLs scale, and the TUGT, which did not change significantly between visits. Self-reported measures revealed less impairment.

IMPLICATIONS FOR NURSING

Monitoring FS using self-reported and performance-based measures can ensure that older patients receive timely support.

Race Differences in Post-Acute Physical Therapy Utilization and Patient-Reported Function after Total Knee Arthroplasty

OBJECTIVE

This observational cohort study included patients of Black and White race and non-Hispanic ethnicity with end-stage knee osteoarthritis who were scheduled to receive total knee arthroplasty (TKA) surgery. We examined whether there are race differences in (1) use of physical therapy (PT) across all post-acute settings and (2) patient-reported physical function following TKA.

METHODS

We collected pre- and post-operative physical function data and post-operative rehabilitation data on 104 Black and White individuals undergoing TKA. Regression analyses and independent samples t-tests were used to explore the predictive value of race on post-operative functional outcome and compare PT utilization within each post-acute setting and across all post-acute rehabilitation settings.

RESULTS

Total PT received was similar between White and Black participants, but there were significant race differences in PT utilization within specific settings. Race did not significantly predict function after TKA, but Black participants had slightly lower self-reported function both before and after surgery than White participants.

CONCLUSION

This is the first study to examine both PT utilization and functional outcomes in a sample of individuals undergoing TKA, and results indicate differences in where post-operative PT is received between Black and White patients.

Remote Patient Monitoring with Wearable Sensors Following Knee Arthroplasty

(Background) Inertial Measurement Units (IMUs) provide a low-cost, portable solution to obtain functional measures similar to those captured with three-dimensional gait analysis, including spatiotemporal gait characteristics. The primary aim of this study was to determine the feasibility of a remote patient monitoring (RPM) workflow using ankle-worn IMUs measuring impact load, limb impact load asymmetry and knee range of motion in combination with patient-reported outcome measures. (Methods) A pilot cohort of 14 patients undergoing primary knee arthroplasty for osteoarthritis was prospectively enrolled. RPM in the community was performed weekly from 2 up to 6 weeks post-operatively using wearable IMUs. The following data were collected using IMUs: mobility (Bone Stimulus and cumulative impact load), impact load asymmetry and maximum knee flexion angle. In addition, scores from the Oxford Knee Score (OKS), EuroQol Five-dimension (EQ-5D) with EuroQol visual analogue scale (EQ-VAS) and 6 Minute Walk Test were collected. (Results) On average, the Bone Stimulus and cumulative impact load improved 52% (p = 0.002) and 371% (p = 0.035), compared to Post-Op Week 2. The impact load asymmetry value trended (p = 0.372) towards equal impact loading between the operative and non-operative limb. The mean maximum flexion angle achieved was 99.25° at Post-Operative Week 6, but this was not significantly different from pre-operative measurements (p = 0.1563). There were significant improvements in the mean EQ-5D (0.20; p = 0.047) and OKS (10.86; p < 0.001) scores both by 6 weeks after surgery, compared to pre-operative scores. (Conclusions) This pilot study demonstrates the feasibility of a reliable and low-maintenance workflow system to remotely monitor post-operative progress in knee arthroplasty patients. Preliminary data indicate IMU outputs relating to mobility, impact load asymmetry and range of motion can be obtained using commercially available IMU sensors. Further studies are required to directly correlate the IMU sensor outputs with patient outcomes to establish clinical significance.

Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post-TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self-reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross-sectionally at 6-24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (β = .245, p = .044), knee extension moment (β = .283, p = .049), and knee extension excursion (β = .298, p = .038). Older age (β = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (β = -.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (β = -.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (β = .585, p < .001), knee extensor moment (β = .481, p < .001), and knee flexion excursion (β = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post-TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post-TKA.

A clinical test examination procedure to identify knee compartment overloading: A reliability and validity study using SPECT-CT as reference

BACKGROUND

Mechanical forces and joint misalignment are considered risk factors for the development of knee osteoarthritis (KOA). Early detection of KOA and distinction between lateral and medial compartment overloading (CO), might be important to inform appropriate preventative interventions. This study evaluated reliability and validity of a test battery consisting of ten clinical tests to predict knee CO.

METHODS

Independent observers examined 30 participants with symptoms of KOA. Inter-rater reliability of the ten tests, as well as the anticipated CO based on the whole test battery, was determined. All participants received a SPECT-CT, which served as reference standard for CO. The agreement for CO between SPECT-CT and clinical examination was assessed to determine criterion validity.

RESULTS

The Kappa coefficients (k) for the ten individual clinical tests ranged from 0.19 to 0.80. The k for determining CO was 0.52 (95% CI = 0.28-0.76). The agreement for CO between SPECT-CT and clinical examination (i.e. criterion validity) yielded a k of 0.26 (95% CI = -0.06 - 0.58). Logistic regression indicated that valgus alignment was strongly related with lateral CO. No other relationships were found between individual tests and CO.

CONCLUSION

Accurate measurement of frontal plane knee angle is important to determine CO. This particular test yielded good reliability, but low validity. Reliability of the nine remaining clinical tests was fair to moderate. Criterion validity of the clinical examination to predict CO was low. Therefore, this test battery in its current form cannot be used in practice to determine CO.

Knee osteoarthritis: key treatments and implications for physical therapy

BACKGROUND

Knee osteoarthritis (OA) is a chronic progressive disease that imparts a substantial socioeconomic burden to society and healthcare systems. The prevalence of knee OA has dramatically risen in recent decades due to consistent increases in life expectancy and obesity worldwide. Patient education, physical exercise, and weight loss (for overweight or obese individuals) constitute the first-line knee OA treatment approach. However, less than 40% of patients with knee OA receive this kind of intervention. There is an unmet need for healthcare professionals treating individuals with knee OA to understand the current recommended treatment strategies to provide effective rehabilitation.

OBJECTIVE

To guide physical therapists in their clinical decision making by summarizing the safest and most efficacious treatment options currently available, and by delineating the most traditional outcome measures used in clinical research for knee OA.

CONCLUSION

There is a need for healthcare providers to abandon low-quality and ineffective treatments and educate themselves and their patients about the current best evidence-based practices for knee OA.

Concept verification of a Remote Automatic Scoring System for Evaluating Knee Function after Total Knee Arthroplasty

The Knee Society Score (KSS) is the most commonly used scale for evaluating postoperative pain and physical function after total knee arthroplasty (TKA). However, this scale requires clinic visiting, which is not quite convenient. Our concept verification study demonstrated a remote automatic system for evaluating knee function after TKA using the KSS. The remote scoring system consists of two modules for data acquisition, an application for patients, a cloud server, and an application for doctors. The kinematic data are collected by the data acquisition modules and transmitted to the patient application via Bluetooth. The data acquisition module contains a motion sensor, a microcontroller unit, a power supply, and a Bluetooth module. The motion sensor consists of an accelerometer, a gyroscope, and a geomagnetic sensor, all of which are three-axis instruments. Using the nine-axis data, the three-dimensional (3D) angles are calculated according to the theory of attitude and heading reference system. The KSS score is calculated using a scoring algorithm in the patient application and transmitted to the doctor application through the cloud server. The knee function of 10 patients treated with unilateral TKA was evaluated by both a doctor and the remote scoring system. The consistency in KSS between the doctor and the system was analyzed using the paired t-test. The remote scoring system successfully recorded knee function data and transmitted the scores from the patient application to the doctor application through the cloud server. There was no significant difference in the KSS scores evaluated by the doctor and that by the system (p = 0.326). This remote automatic scoring system provides a reliable and convenient method for evaluating knee function after TKA at home.

Psychometric properties of the 4-meter walk test after total knee arthroplasty

OBJECTIVE

To determine the reliability, responsiveness, and convergent validity of the Four-Meter Walk Test (4mWT) compared to the Six-Minute Walk Test (6MWT) surrounding total knee arthroplasty (TKA).

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Research laboratory.

PARTICIPANTS

One hundred sixty-two patients (aged 63.5 ± 7.4 (mean ± sd) years; 89 females) undergoing TKA participated.

MAIN OUTCOME MEASURES

4mWT (usual and fastest) and 6MWT were measured 1-2 weeks preoperatively, and 1, 2, 3, 6 and 12 months post-operatively.

RESULTS

4mWT demonstrated excellent test-retest reliability with Interclass Correlation Coefficients (ICC's) ranging from 0.80 to 0.93 s. 4mWT also demonstrated small measurement error with Standard Error of Measurement (SEM) ranging from 0.15 to 0.35 s. 4mWT (fastest) demonstrated similar responsiveness to 6mWT in the first 2 months after surgery and better responsiveness from 2 to 3 months after surgery. Convergent validity between 6MWT and 4mWT (fastest) was high, with Pearson correlation coefficients ranging from 0.73 to 0.81.

CONCLUSIONS

The 4mWT (fastest) has excellent test-retest reliability, shows high responsiveness sufficient for clinical outcomes in the immediate postoperative time periods, and exhibits high convergent validity with 6MWT. Given space and time requirements to conduct each test, 4mWT may be preferred for routine clinical assessment.IMPLICATIONS FOR REHABILITATIONWalking ability•Walking is an important functional ability for patients who undergo total knee arthroplasty (TKA).•While the Six-Minute Walk Test is a validated measure of walking ability in the TKA population, its clinical utility is limited by the space and time it takes to perform the test.•The Four-Meter Walk Test (fastest speed) is a valid, reliable, and responsive alternative to the 6MWT and is recommended for routine clinical use after TKA.

Physical Performance Tests Provide Distinct Information in Both Predicting and Assessing Patient-Reported Outcomes Following Lumbar Spine Surgery

STUDY DESIGN

Secondary analysis of randomized controlled trial data.

OBJECTIVE

The aim of this study was to examine whether preoperative physical performance is an independent predictor of patient-reported disability and pain at 12 months after lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Patient-reported outcome measures (PROMs) are commonly used to assess clinical improvement after lumbar spine surgery. However, there is evidence in the orthopedic literature to suggest that PROMs should be supplemented with physical performance tests to accurately evaluate long-term outcomes.

METHODS

A total of 248 patients undergoing surgery for degenerative lumbar spine conditions were recruited from two institutions. Physical performance tests (5-Chair Stand and Timed Up and Go) and PROMs of disability (Oswestry Disability Index: ODI) and back and leg pain (Brief Pain Inventory) were assessed preoperatively and at 12 months after surgery.

RESULTS

Physical performance tests and PROMs significantly improved over 12 months following lumbar spine surgery (P < 0.01). Weak correlations were found between physical performance tests and disability and pain (ρ = 0.15 to 0.32, P < 0.05). Multivariable regression analyses controlling for age, education, preoperative outcome score, fusion, previous spine surgery, depressive symptoms, and randomization group found that preoperative 5-Chair Stand test was significantly associated with disability and back pain at 12-month follow-up. Each additional 10 seconds needed to complete the 5-Chair Stand test were associated with six-point increase in ODI (P = 0.047) and one-point increase in back pain (P = 0.028) scores. The physical performance tests identified an additional 14% to 19% of patients as achieving clinical improvement that were not captured by disability or pain questionnaires.

CONCLUSION

Results indicate that physical performance tests may provide distinct information in both predicting and assessing clinical outcomes in patients undergoing lumbar spine surgery. Our findings suggest that the 5-Chair Stand test may be a useful test to include within a comprehensive risk assessment before surgery and as an outcome measure at long-term follow-up.

LEVEL OF EVIDENCE

3.

Predicting Subjective Recovery from Lower Limb Surgery Using Consumer Wearables

Introduction

A major challenge in the monitoring of rehabilitation is the lack of long-term individual baseline data which would enable accurate and objective assessment of functional recovery. Consumer-grade wearable devices enable the tracking of individual everyday functioning prior to illness or other medical events which necessitate the monitoring of recovery trajectories.

Methods

For 1,324 individuals who underwent surgery on a lower limb, we collected their Fitbit device data of steps, heart rate, and sleep from 26 weeks before to 26 weeks after the self-reported surgery date. We identified subgroups of individuals who self-reported surgeries for bone fracture repair (n = 355), tendon or ligament repair/reconstruction (n = 773), and knee or hip joint replacement (n = 196). We used linear mixed models to estimate the average effect of time relative to surgery on daily activity measurements while adjusting for gender, age, and the participant-specific activity baseline. We used a sub-cohort of 127 individuals with dense wearable data who underwent tendon/ligament surgery and employed XGBoost to predict the self-reported recovery time.

Results

The 1,324 study individuals were all US residents, predominantly female (84%), white or Caucasian (85%), and young to middle-aged (mean age 36.2 years). We showed that 12 weeks pre- and 26 weeks post-surgery trajectories of daily behavioral measurements (steps sum, heart rate, sleep efficiency score) can capture activity changes relative to an individual's baseline. We demonstrated that the trajectories differ across surgery types, recapitulate the documented effect of age on functional recovery, and highlight differences in relative activity change across self-reported recovery time groups. Finally, using a sub-cohort of 127 individuals, we showed that long-term recovery can be accurately predicted, on an individual level, only 1 month after surgery (AUROC 0.734, AUPRC 0.8). Furthermore, we showed that predictions are most accurate when long-term, individual baseline data are available.

Discussion

Leveraging long-term, passively collected wearable data promises to enable relative assessment of individual recovery and is a first step towards data-driven intervention for individuals.

Discordance between self-reported and performance-based function among knee osteoarthritis surgical patients: Variations by sex and obesity

Background

There is currently no standardized method for measuring functional status in knee osteoarthritis (OA) patients, despite that it is one of the top priorities when determining eligibility for total knee arthroplasty (TKA). The purpose of the current investigation was to identify factors associated with discordance between individual self-report and performance-based measures of function for obese and non-obese men and women with knee OA.

Methods

In a cohort of 727 knee OA patients scheduled for TKA, physical function prior to surgery was assessed with the self-reported physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-pf), and the performance-based Timed Up and Go (TUG). Data on sociodemographic characteristics, health status, knee pain intensity, symptomatic joint site count, and pain catastrophizing were collected via questionnaire. The primary outcome was the difference in rescaled score between a participant’s self-report and performance-based measures of function. Multivariable linear regression stratified by sex and obesity status was used to identify factors associated with discordance.

Results

The mean age of participants was 65.5 years and 55% were women. With younger age, self-reported scores indicated increasingly worse function compared to performance-based scores, regardless of sex or obesity status. Among non-obese individuals, greater knee pain intensity was associated with a participant’s self-report score indicating increasingly worse function compared to their performance-based score. For obese women, pain catastrophizing, and number of symptomatic joints were also associated with discordance as was reporting fewer comorbidities.

Conclusions

Physical function may be differentially represented by self-reported and performance-based measures depending on a variety of patient factors. Our findings add to the evidence which suggests both measures should be used when assessing functional status prior to TKA.

Modelling Patient Behaviour Using IoT Sensor Data: a Case Study to Evaluate Techniques for Modelling Domestic Behaviour in Recovery from Total Hip Replacement Surgery

The UK health service sees around 160,000 total hip or knee replacements every year and this number is expected to rise with an ageing population. Expectations of surgical outcomes are changing alongside demographic trends, whilst aftercare may be fractured as a result of resource limitations. Conventional assessments of health outcomes must evolve to keep up with these changing trends. Health outcomes may be assessed largely by self-report using Patient Reported Outcome Measures (PROMs), such as the Oxford Hip or Oxford Knee Score, in the months up to and following surgery. Though widely used, many PROMs have methodological limitations and there is debate about how to interpret results and definitions of clinically meaningful change. With the development of a home-monitoring system, there is opportunity to characterise the relationship between PROMs and behaviour in a natural setting and to develop methods of passive monitoring of outcome and recovery after surgery. In this paper, we discuss the motivation and technology used in long-term continuous observation of movement, sleep and domestic routine for healthcare applications, such as the HEmiSPHERE project for hip and knee replacement patients. In this case study, we evaluate trends evident in data of two patients, collected over a 3-month observation period post-surgery, by comparison with scores from PROMs for sleep and movement quality, and by comparison with a third control home. We find that accelerometer and indoor localisation data correctly highlight long-term trends in sleep and movement quality and can be used to predict sleep and wake times and measure sleep and wake routine variance over time, whilst indoor localisation provides context for the domestic routine and mobility of the patient. Finally, we discuss a visual method of sharing findings with healthcare professionals.

How New Technology Is Improving Physical Therapy

PURPOSE OF REVIEW

As rehabilitation patient volume across the age spectrum increases and reimbursement rates decrease, clinicians are forced to produce favorable outcomes with limited resources and time. The purpose of this review is to highlight new technologies being utilized to improve standardization and outcomes for patients rehabilitating orthopedic injuries ranging from sports medicine to trauma to joint arthroplasty.

RECENT FINDINGS

A proliferation of new technologies in rehabilitation has recently occurred with the hope of improved outcomes, better patient compliance and safety, and return to athletic performance. These include technologies applied directly to the patient such as exoskeletons and instrumented insoles to extrinsic applications such as biofeedback and personalized reference charts. Well-structured randomized trials are ongoing centered around the efficacy and safety of these new technologies to help guide clinical necessity and appropriate application. We present a range of new technologies that may assist a diverse population of orthopedic conditions. Many of these interventions are already supported by level 1 evidence and appear safe and feasible for most clinical settings.

Current clinical utilisation of wearable motion sensors for the assessment of outcome following knee arthroplasty: a scoping review

OBJECTIVES

Wearable motion sensors are used with increasing frequency in the evaluation of gait, function and physical activity within orthopaedics and sports medicine. The integration of wearable technology into the clinical pathway offers the ability to improve post-operative patient assessment beyond the scope of current, questionnaire-based patient-reported outcome measures. This scoping review assesses the current methodology and clinical application of accelerometers and inertial measurement units for the evaluation of patient activity and functional recovery following knee arthroplasty.

DESIGN

This is a systematically conducted scoping review following Joanna Briggs Institute methodology for scoping reviews and reported consulting the Preferred Reporting Items for Systematic Review and Meta-Analyses extension for scoping reviews. A protocol for this review is registered with the Open Science Framework (https://osf.io/rzg9q).

DATA SOURCES

CINAHL, EMBASE, MEDLINE and Web of Science databases were searched for manuscripts published between 2008 and 2019.

ELIGIBILITY CRITERIA

We included clinical studies reporting the use of any combination of accelerometers, pedometers or inertial measurement units for patient assessment at any time point following knee arthroplasty.

DATA EXTRACTION AND SYNTHESIS

Data extracted from manuscripts included patient demographics, sensor technology, testing protocol and sensor-based outcome variables.

RESULTS

45 studies were identified, including 2076 knee arthroplasty patients, 620 patients with end-stage osteoarthritis and 449 healthy controls. Primary aims of the identified studies included functional assessment, physical activity monitoring and evaluation of knee instability. Methodology varied widely between studies, with inconsistency in reported sensor configuration, testing protocol and output variables.

CONCLUSIONS

The use of wearable sensors in evaluation of knee arthroplasty procedures is becoming increasingly common and offers the potential to improve clinical understanding of recovery and rehabilitation. While current studies lack consistency, significant opportunity exists for the development of standardised measures and protocols for function and physical activity evaluation.