Evaluation of health outcomes in osteoarthritis patients after total knee replacement: a two-year follow-up

The dynamic impact of Joint Awareness on Quality of Life after Total Knee Arthroplasty: a longitudinal study

BACKGROUND

Joint Awareness is thought to be closely linked to Quality of Life (QoL) for patients undergoing Total Knee Arthroplasty (TKA), yet to date there have been no longitudinal studies to explore how Joint Awareness actually affects QoL. The purpose of this study was therefore to examine the development of Joint Awareness and QoL after TKA as well as the dynamic impact of Joint Awareness on QoL.

METHODS

A total of 342 patients were followed up at 3 months (T1), 6 months (T2), and 12 months (T3) after TKA. Joint Awareness was evaluated using the Forgotten Joint Score-12 (FJS-12), and QoL was measured by SF-36. We used repeated measures analysis of variance to estimate the development of Joint Awareness and QoL and employed a cross-lagged model to examine the dynamic relationship between Joint Awareness and QoL.

RESULTS

Both Joint Awareness and QoL improved with postoperative time (p < 0.001). Importantly, T1 Joint Awareness positively predicted T2 physical QoL (p < 0.001), and T2 Joint Awareness positively predicted T3 physical QoL (p < 0.001). Nevertheless, Joint Awareness had no predictive effect on mental QoL (p = 0.082-0.931).

CONCLUSIONS

In different periods after TKA, Joint Awareness and QoL both increased monotonically, and Joint Awareness positively predicted physical QoL. These findings indicate that focusing on Joint Awareness may be a priority when trying to improve the postoperative life of patients.

Self-care behaviors in older adults suffering from knee osteoarthritis: Application of theory of planned behavior

Background

Osteoarthritis is one of the main reasons causing disablement. Educational intervention for self-care behaviors of patients suffering from knee osteoarthritis is important because its effect on quality of patient life decreases the economic burden of disorder on society and family. This study aimed to investigate the effect of educational intervention based on the theory of planned behavior (TPB) on promoting self-care behaviors in elderly patients suffering from knee osteoarthritis.

Methods

This quasi-experimental study was performed on 200 elderlies suffering from knee osteoarthritis in the rheumatology clinics of Shiraz, Iran, in 2019. The subjects were divided into two groups (100 experimental and 100 control). Before and after 4 months, both experimental and control groups filled a questionnaire. After administering a pre-test to both groups, only the experimental group was trained based on the TPB constructs on self-care behaviors in elderly people suffering from knee osteoarthritis in eight sessions by presenting educational films and images, power points, and group discussions for solving problems.

Results

The mean age of the experimental group was 67.25 ± 3.64, and the mean age of the control group was 66.12 ± 3.50. The average scores of attitudes, subjective norms, perceived behavioral control, intention, and behavior before the educational intervention did not have significant differences in experimental and control groups, however, 4 months after the educational intervention, the paired t-test indicated significant enhancement in every construct in the experimental group, but no significant changes in the control group.

Conclusion

According to the results, the educational intervention increased the self-care behaviors of patients suffering from knee osteoarthritis based on the theory of planned behavior. Therefore, the results of this study can be used in theory-based intervention strategies for self-care behaviors of patients suffering from knee osteoarthritis.

Sleep Disturbances and Disorders in Patients with Knee Osteoarthritis and Total Knee Arthroplasty

➤

There is increasing evidence that patient-reported outcomes following total knee arthroplasty (TKA) are associated with psychosocial factors and pain catastrophizing. Sleep disturbance, pain, and mental health have a complex interaction, which, if unrecognized, can be associated with impaired patient-reported outcomes and dissatisfaction following TKA.

➤

The gold standard of objective sleep assessment is polysomnography, which is not feasible to use routinely for TKA patients. Wearable devices are a validated and less costly alternative.

➤

Subjective sleep measures, such as the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, or Patient-Reported Outcomes Measurement Information System (PROMIS) computerized adaptive test sleep domains, are simple to administer and provide additional insight into sleep disturbance. Although objective and subjective measures do not correlate precisely, they can be informative together.

➤

Sleep disturbances in the elderly population are common and multifactorial in etiology, stemming from the interplay of sleep disorders, medication side effects, and pain. Commonly prescribed medications following TKA as well as postoperative pain can exacerbate underlying sleep disturbances.

➤

Obstructive sleep apnea (OSA) is prevalent in patients seeking TKA. In the setting of OSA, postoperative opioids can cause respiratory depression, resulting in consequences as severe as death. A standardized multimodal pain protocol including anti-inflammatories and gamma-aminobutyric acid (GABA) analogues may allow for decreased reliance on opioids for pain control.

➤

Surgeons should reassure patients that postoperative sleep disturbance is common and transient, collaborate with the patient's primary care doctor to address sleep disturbance, and avoid prescription of pharmaceutical sleep aids.

An automatic measurement system of distal femur morphological parameters using 3D slicer software

In the field of joint surgery, the computer-aided design of knee prostheses suitable for the Chinese population requires a large quantity of anatomical knee data. In this study, we propose a new method that uses 3D Slicer software to automatically measure the morphological parameters of the distal femur. First, 141 femur samples were segmented from CT data to establish the femoral shape library. Next, balanced iterative reducing and clustering using hierarchies (BIRCH) combined with iterative closest point (ICP) and generalised procrustes analysis (GPA) were used to achieve fast registration of the femur samples. The statistical model was automatically calculated from the registered femur samples, and an orthopaedic surgeon marked the points on the statistical model. Finally, we developed an automatic measurement system using 3D Slicer software, and a deformable model matching method was applied to establish the point correspondence between the statistical model and the other samples. By matching points on the statistical model to corresponding points in other samples, we measured all other samples. We marked six points and measured eight parameters. We evaluated the performance of automatic matching by comparing the points marked manually with those matched automatically and verified the accuracy of the system by comparing the manual and automatic measurement results. The results indicated that the average error of the automatic matching points was 1.03 mm, and the average length error and average angle error measured automatically by the system were 0.37 mm and 0.63°, respectively. These errors were smaller than the intra-rater and inter-rater errors measured manually by two different surgeons, which showed that the accuracy of our automatic method was high. Taken together, this study established an accurate and automatic measurement system for the distal femur based on the secondary development of 3D Slicer software to assist orthopaedic surgeons in completing the measurements of big data and further promote the improved design of Chinese-specific knee prostheses.

Clinical Course of Pain and Function Following Total Knee Arthroplasty: A Systematic Review and Meta-Regression

BACKGROUND

Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality meta-analysis that outlines the clinical course of pain and function post-TKA.

METHODS

The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression.

RESULTS

In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.4-79.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively.

CONCLUSION

Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function.

Improvements in functional outcome and quality of life are not sustainable for patients ≥ 68 years old 10 years after total knee arthroplasty

PURPOSE

The aims of this study are to evaluate whether improvements in functional outcome and quality of life are sustainable 10 years after total knee arthroplasty (TKA), and the age cut-off for clinical deterioration in outcomes METHODS: Prospectively collected registry data of 120 consecutive patients who underwent TKA at a tertiary hospital in 2006 was analysed. All patients were assessed at 6 months, 2 years and 10 years using the Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Short-Form 36 Physical/Mental Component Scores and postoperative satisfaction. One-way ANOVA was used to compare continuous variables, while Chi-squared test to compare categorical variables. Multivariate logistic regression and receiver operating curve analysis was performed to evaluate the predictive factors associated with deterioration of scores postoperatively.

RESULTS

Significant improvements were noted in all functional outcome and quality of life scores at 6 months after TKA. Between 6 months and 2 years, the KSFS and OKS continued to improve but the KSKS, PCS and MCS plateaued. Between 2 and 10 years, there was a deterioration in the KSFS and OKS, whilst KSKS, PCS and MCS were maintained. Increasing age was noted to be a significant risk factor for deterioration of KSFS at 10 years with age ≥ 68 as the cut-off value. 91.7% of patients with KSFS Minimally Clinically Important Difference(MCID) (≥ 7 points) continued to be satisfied after 10 years compared to 100.0% who did not experience KSFS MCID deterioration (p = 0.02).

CONCLUSION

Patients ≥ 68 years experience deterioration in functional outcomes and quality of life from 2 to 10 years after TKA.

LEVEL OF EVIDENCE

Retrospective study, Level III.

Associations of the modified STarT back tool and Hospital Anxiety and Depression Scale (HADS) with gait speed and knee pain in knee osteoarthritis: a retrospective cohort study

OBJECTIVE

The association of the modified STarT Back Tool (mSBT) psychosocial measure with gait speed and knee pain in knee osteoarthritis is not well defined. This study aimed to, in patients with knee osteoarthritis, (i) examine the convergent validity of mSBT with the Hospital Anxiety and Depression Scale (HADS) and (ii) compare the predictive validity of mSBT and HADS with gait speed and knee pain.

METHODS

We performed a retrospective cohort analysis of mSBT, HADS, gait speed, and knee pain outcomes data collected from 119 patients who received outpatient physical therapy. Of these patients who were evaluated at their first (baseline) physical therapy visit, 55 had available data at the Week-16 follow-up visit.

RESULTS

mSBT and HADS showed moderately strong pairwise correlations (Spearman correlation > 0.57; p < 0.001). After adjusting for age, sex, body weight, and knee impairment variables in multivariable linear mixed-effects analyses, mSBT was associated with gait speed (p < 0.001) and knee pain intensity (p < 0.001) and it had comparable strength of association as HADS. In within-patient regression analyses, change in mSBT was associated with changes in gait speed (p = 0.04) and knee pain (p = 0.01) over 16 weeks.

CONCLUSION

The mSBT had convergent validity with HADS and it showed predictive validity with gait speed and knee pain in knee osteoarthritis. Although broader validation is required, the 5-item mSBT psychosocial measure may be applied as part of routine clinical care to assess psychological distress in patients with knee osteoarthritis. IMPLICATIONS FOR REHABILITATION The 5-item psychosocial subscale of the modified STarT Back tool (mSBT) showed good convergent validity with the 14-item Hospital Anxiety and Depression Scale in patients with knee osteoarthritis. The mSBT psychosocial subscale showed predictive validity, at both cross-sectional and longitudinal levels, with gait speed and knee pain in patients with knee osteoarthritis. The mSBT can potentially be used in the busy clinical setting to assess psychological distress in patients with knee osteoarthritis.

Effects of infrapatellar fat pad preservation versus resection on clinical outcomes after total knee arthroplasty in patients with knee osteoarthritis (IPAKA): study protocol for a multicentre, randomised, controlled clinical trial

INTRODUCTION

The infrapatellar fat pad (IPFP) is commonly resected during total knee arthroplasty (TKA) for better exposure. However, our previous studies have suggested that IPFP size was protective against, while IPFP signal intensity alteration was detrimental on knee symptoms and structural abnormalities. We hypothesise that an IPFP with normal qualities, rather than abnormal qualities, should be preserved during TKA. The aim of this study is to compare, over a 1-year period, the postoperative clinical outcomes of IPFP preservation versus resection after TKA in patients with normal or abnormal IPFP signal intensity alteration on MRI.

METHODS AND ANALYSIS

Three hundred and sixty people with end-stage knee osteoarthritis and on the waiting list for TKA will be recruited and identified as normal IPFP quality (signal intensity alteration score ≤1) or abnormal IPFP quality (signal intensity alteration score ≥2). Patients in each hospital will then be randomly allocated to IPFP resection group or preservation group. The primary outcomes are the summed score of self-reported Knee Injury and Osteoarthritis Outcome Score (KOOS), KOOS subscales assessing function in daily activities and function in sport and recreation. Secondary endpoints will be included: KOOS subscales (pain, symptoms and quality of life), Knee Society Score, 100 mm Visual Analogue Scale (VAS) Pain, timed up-and-go test, patellar tendon shortening, 100 mm VAS self-reported efficacy of reduced pain and increased quality of life, and Insall-Salvati index assessed on plain X-ray. Adverse events will be recorded. Intention-to-treat analyses will be used.

ETHICS AND DISSEMINATION

The study is approved by the local Medical Ethics Committee (Zhujiang Hospital Ethics Committee, reference number 2017-GJGBK-001) and will be conducted according to the principle of the Declaration of Helsinki (64th, 2013) and the Good Clinical Practice standard, and in compliance with the Medical Research Involving Human Subjects Act . Data will be published in peer-reviewed journals and presented at conferences, both nationally and internationally.

TRIAL REGISTRATION NUMBER

This trial was registered at Clinicaltrial.gov website on 19 October 2018 with identify number NCT03763448.

Functional Outcomes After Critical Pathway for Inpatient Rehabilitation of Total Knee Arthroplasty

OBJECTIVE

To investigate functional outcomes after the application of a critical pathway for inpatient rehabilitation of total knee arthroplasty (TKA).

METHODS

A total of 184 patients (57 males and 127 females; average age, 71.5±5.9 years) who underwent unilateral or bilateral TKA were included. The critical pathway included early, intensive individualized rehabilitation exercises. Patients completed the following performance-based physical function tests: the stair climbing test (SCT), 6-minute walk test (6MWT), and Timed Up and Go test (TUG) as well as measurement of isometric knee flexor and extensor strength of the operated knee, gait speed, and range of knee flexion and extension. Self-reported physical function and pain were measured using the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS), respectively, and self-reported quality of life was measured using the EuroQoL 5 dimension (EQ-5D) questionnaire. These evaluations were performed preoperatively and at 1 month and 3 months postoperatively.

RESULTS

Performance-based and self-reported physical function and quality of life measures improved nonlinearly over time. Specifically, the 6WMT, TUG, gait speed, WOMAC-pain, WOMAC-function, VAS, and EQ-5D scores showed a significant improvement at 1-month post-TKA, whereas SCT, peak torque of the knee extensors and flexors, and WOMAC-stiffness scores showed gradual, but substantial, improvements over 3 months. There were between-group differences (unilateral and bilateral TKA groups) in the time course of the SCT, 6MWT, TUG, VAS, WOAMC-stiffness, and WOMAC-function results.

CONCLUSION

Patients who underwent critical pathway rehabilitation after TKA showed significant improvements in functional measurements during the first 3 months post-surgery.

Different improvement trends in gait function and quadriceps strength early after total knee arthroplasty

[Purpose] Improved quadriceps strength is a primary target of rehabilitation early after total knee arthroplasty. However, patients demonstrate varying improvement trends in gait function and quadriceps strength. This study evaluated the relationship between improvements in quadriceps strength and gait function. [Participants and Methods] The study included 49 patients who were scheduled to undergo unilateral total knee arthroplasty. Gait function, bilateral quadriceps strength, and pain were assessed in all patients. All assessments were performed preoperatively and at 2 and 3 weeks postoperatively. [Results] A significant correlation between gait function and the quadriceps strength on the operated side was observed preoperatively and 3 weeks postoperatively. The quadriceps strength on the non-operated side was significantly correlated with gait function at all time points. Multiple regression analysis showed that the quadriceps strength on the non-operated side was significantly associated with gait function, except the gait speed at 2 weeks. However, the quadriceps strength on the operated side was not observed to be an independent variable at all time points. [Conclusion] The quadriceps strength on the operated side is not an important determinant of gait function. It may be necessary to reconsider typical rehabilitation programs by focusing on the quadriceps strength on the operated side in patients undergoing total knee arthroplasty.

The New Surgical Technique for Improving Total Knee and Hip Arthroplasty Outcomes: Patient Selection

BACKGROUND

Inclusion of patient satisfaction scores in setting reimbursements has been suggested by health care policy makers to contain cost and improve outcomes. The Short Form 36 Health Survey (SF-36) score provides a health-related quality of life (HRQoL) measure of arthroplasty outcome. Although previous work identified factors that influence this score for hip and knee arthroplasty patients, they did not focus on how a surgeon might use this information in a clinical setting. The present study examined whether relatively simple criteria might identify patients more likely to experience minimal HRQoL improvement.

METHODS

"Improvements" in SF-36 composite physical scores and subscales were calculated from the difference between initial (preoperative) and SF-36 scores at 1 year. The rates of achieving a clinically significant improvement were compared between patient groups.

RESULTS

After knee arthroplasty, women and younger patients achieved a clinically significant improvement in physical function more frequently than men and older patients (P = .04 and .02, respectively). The largest differences in improvement occurred between the diabetic and nondiabetic groups (P = .001), where the diabetic patients with ≥2 additional comorbidities demonstrated the lowest rate of achieving a clinically significant improvement in physical function and bodily pain. In comparison, in hip patients only age had significant influence on gains in physical function, but this did not alter the rate at which patients achieved a clinically significant improvement.

CONCLUSION

These data indicate simple screening criteria can identify patients where arthroplasty might provide marginal HRQoL improvement. They suggest HRQoL-based reimbursement incentives will favor practices with younger, healthier patient populations.

Improvements in physical function and pain sustained for up to 10 years after knee or hip arthroplasty irrespective of mental health status before surgery

Background and purpose - There are concerns that mental health (MH) may influence outcomes of total knee arthroplasty (TKA) or total hip arthroplasty (THA). We examined effects of poor MH before surgery on long-term outcomes of osteoarthritis-related TKA or THA in women. Patients and methods - The data were from 9,737 middle-aged participants (47-52 years) and 9,292 older participants (73-78 years) in the Australian Longitudinal Study on Women's Health who completed surveys between 1998 and 2013. Dates of arthroplasties were obtained from the Australian Orthopaedics Association National Joint Replacement Registry. Participants without procedures were matched with participants with procedures. Trajectories of the Short-Form 36 scores for physical functioning, bodily pain, social functioning, and mental health based on mixed modeling were plotted for participants with and without surgery (stratified according to mental health, separately for TKA and THA, and for middle-aged and older participants). Results - In middle-aged women with poor and good MH, TKA improved physical function and reduced bodily pain, with improvements sustained up to 10 years after surgery. TKA contributed to restoration of social function in women with good MH, but this was less clear in women with poor MH. In both MH groups, mental health appeared to be unaffected by TKA. Similar patterns were observed after THA, and in older women. Interpretation - Recovery of physical and social function and reductions in pain were sustained for up to 10 years after surgery. Improvements in physical function and pain were also observed in women with poor mental health. Thus, in our view poor mental health should not be a contraindication for arthroplasty.

Patient-reported health outcomes after total hip and knee surgery in a Dutch University Hospital Setting: results of twenty years clinical registry

Background

Patient-Reported Outcome (PRO) measurement is a method for measuring perceptions of patients on their health and quality of life. The aim of this paper is to present the results of PRO measurements in total hip and knee replacement as routinely collected during 20 years of surgery in a university hospital setting.

Methods

Data of consecutive patients between 1993 and 2014 were collected. Health outcomes were measured pre-surgery and at 3, 6, and 12 months post-surgery. Outcomes for hip replacement were measured with the Harris Hip Score (HHS) and Oxford Hip Score (OHS). Outcomes for knee replacement were measured with the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Knee Society Score (KSS). A Visual Analog Scale (VAS) for pain was used. Absolute and relative Minimal Clinically Important Differences (MCID) were estimated. Generalized estimating equation analysis was used for estimating mean outcomes. Trends over time were analyzed.

Results

The database contained 2,089 patients with hip replacement, and 704 patients with knee replacement. Mean HHS and OHS scores in primary hip replacement at 12 months post-surgery were 86.7 (SD: 14.5) and 41.1 (SD: 7.5) respectively. Improvements on the HHS based on absolute MCID was lower for revisions compared to primary hip replacements, with 72.4% and 87.0% respectively. Mean WOMAC and KSS scores in knee replacement at 12 months post-surgery were 21.5 (SD: 18.2) and 67.0 (SD: 26.4) respectively. Improvements based on absolute MCID were lowest for the KSS (62.6%) and highest for VAS pain (85.6%). Trend analysis showed a difference in 1 out of 24 comparisons in hip replacement and in 2 out of 9 comparisons in knee replacement.

Conclusions

The functional status of a large cohort of patients significantly improved after hip and knee replacement based on routine data collection. Our study shows the feasibility of the routine collection of PRO data in patients with total hip and knee replacement. The use of PRO data provides opportunities for continuous quality improvement.

Prospective quality of life assessment after hip and knee arthroplasty: short- and mid-term follow-up results

Background

Hip and knee arthroplasty aims to restore the joint function and to improve health-related quality of life (HRQoL) in patients with articular damage. It is important to quantify the HRQoL improvement and when this is achieved. The Oxford knee score and the Oxford hip score were developed to evaluate patients after knee and hip arthroplasty. We sought to evaluate HRQoL changes in the short and mid term following either primary or revision hip and knee arthroplasty.

Methods

Prospective cohort study during a 20-month period (August 2013 to March 2015) in a tertiary referral hospital. Primary arthroplasties secondary to osteoarthritis and any-cause revisions were included (328, 160 knees, and 88 hips). They were divided into 4 groups: (1) primary knee replacement, (2) primary hip replacement, (3) revision knee replacement, and (4) revision hip replacement. Oxford knee and hip scores were obtained prior the surgery and compared with the short- and mid-term follow-up scores.

Results

Follow-up in the short term and mid term was: 75.6% and 67.4%, respectively. Improvement was found in both short-term and mid-term follow-up for each group and for the overall group in HRQoL as measured by the Oxford knee and hip scores (P < .001). The greatest improvement was seen in the short term with an increase of 21 points for primary knee arthroplasty; 24 points for primary hip arthroplasty; 22 points for revision knee arthroplasty; and 23 points for revision hip arthroplasty.

Conclusions

Improvement in HRQoL in patients following primary or revision hip or knee arthroplasty is crucial and can be achieved early after the surgery.

Rationale, design and protocol of a longitudinal study assessing the effect of total knee arthroplasty on habitual physical activity and sedentary behavior in adults with osteoarthritis

Background

Physical activity levels are decreased and sedentary behaviour levels are increased in patients with knee osteoarthritis (OA). However, previous studies have shown that following total knee arthroplasty (TKA), objectively measured physical activity levels do not change compared to before the surgery. Very few studies have objectively assessed sedentary behaviour following TKA. This study aims to assess patterns of objective habitual physical activity and sedentary behaviour in patients with knee OA and to determine whether these change following TKA.

Methods

Patients diagnosed with knee osteoarthritis and scheduled for unilateral primary total knee arthroplasty will be recruited from the Orthopaedic Division at the Charlotte Maxeke Johannesburg Academic Hospital. Eligible participants will have assessments completed one week before the scheduled arthroplasty, six weeks, and six months post-operatively. The primary outcomes are habitual physical activity and sedentary behaviour which will be measured using accelerometry (Actigraph GTX3+ and activPal monitors) at the specific time points. The secondary outcomes will be improvements in osteoarthritis-specific quality of life measures using the following questionnaires: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Knee Society Clinical Rating System (KSS), UCLA activity index; subjective pain scores, and self reported sleep quality.

Discussion

The present study will contribute to the field of musculoskeletal health by providing a rich detailed description of the patterns of accumulation of physical activity and sedentary behaviour in patients with knee OA. These data will contribute to existing knowledge using an objective measurement for the assessment of functional ability after total knee arthroplasty. Although studies have used accelerometry to measure physical activity in knee OA patients, the data provided thus far have not delved into the detailed patterns of how and when physical activity is accumulated before and after TKA. Accurate assessment of physical activity is important for physical activity interventions that target special populations.

Trial registration

NCT02675062 (4 February 2016).

Correlations Between Functional Knee Outcomes and Health-Related Quality of Life After Total Knee Arthroplasty in an Asian Population

BACKGROUND

Current literature evaluating postoperative outcomes after total knee arthroplasty for osteoarthritis in the Asian population is sparse. We aimed to evaluate correlations between improvements in knee outcomes vs changes in generic health-related quality of life.

METHODS

Postoperative outcomes were collected prospectively for 369 patients and compared at a 2-year follow-up using Short-Form 36 (SF-36), Knee Society Score (KSS), and Oxford Knee Score (OKS). The Spearman correlation coefficient was used to evaluate the strength of correlation between changes in knee scores (KSS and OKS) vs changes in each domain of the SF-36 scores.

RESULTS

All parameters achieved statistically significant improvements (P < .05) in postoperative scores at 2-year follow-up with the exception of general health (P = .221) component of SF-36. For KSS knee score, there was low correlation with bodily pain (0.32). For KSS function score, there was moderate correlation with physical functioning (0.57) and low correlation with role physical (0.31) and social functioning (0.36). For OKS, there was moderate correlation with physical functioning (0.61) and social functioning (0.54) and low correlation with role physical (0.38) and bodily pain (0.50). All other parameters of SF-36 showed little correlation (<0.3).

CONCLUSION

Improvements in knee-specific outcomes (KSS and OKS) after total knee arthroplasty correlate well with improvements in physical domains of health-related quality of life (SF-36) but poorly with the mental and social health domains.

Using surgical appropriateness criteria to examine outcomes of total knee arthroplasty in a United States sample

OBJECTIVE

We determined outcomes for patients classified as appropriate, inconclusive, or inappropriate for total knee arthroplasty (TKA) using a modified version of a validated appropriateness algorithm. Outcome measurement was conceptualized as short-term postoperative change attributable primarily to surgery and rehabilitation (2 months) and as longer-term postoperative change and recovery (1 and 2 years).

METHODS

Preoperative and yearly postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function, Knee Injury and Osteoarthritis Outcome Score (KOOS) symptoms and KOOS pain scores were examined for persons undergoing primary TKA in the Osteoarthritis Initiative. Multigroup, 2-piece latent growth curve modeling was used to determine differences in outcome variable changes for each group from presurgery to 2-months postsurgery, as well as over a 2-year postoperative period.

RESULTS

Data from 167 persons with primary TKA were examined. Prevalence rates of appropriate, inconclusive, and inappropriate judgments were 47.9%, 20.8%, and 31.3%, respectively. The inappropriate group showed no change at 2 months following surgery, while appropriate and inconclusive groups had substantial improvement in all outcomes. One-year and 2-year postoperative recovery outcomes were not significantly different among the 3 groups.

CONCLUSION

The inappropriate group was unchanged 2 months after surgery and on average improved by 2.3 WOMAC function points from presurgery to 1 year following surgery based on our models. Appropriate and inconclusive groups improved by an average of 19.8 WOMAC function points at 1-year postsurgery. These data provide a compelling case for consensus-building efforts to define eligibility criteria for TKA with the goals of reducing variation in patient selection and optimizing both change over time and final outcomes.

Preoperative predictors of postoperative opioid usage, pain scores, and referral to a pain management service in total knee arthroplasty

BACKGROUND

Little is known about preoperative predictors of postoperative pain and referral to a recuperative pain management service after total knee arthroplasty (TKA).

QUESTIONS/PURPOSES

We sought to identify the preoperative predictors of postoperative pain scores, referral to a pain management service, and narcotic usage in patients undergoing primary total knee arthroplasty.

METHODS

We performed a prospective cohort study of 97 TKAs from a single surgeon. Pre and 6-week postoperative WOMAC, visual analog pain scale (VAS) scores, narcotic usage, and catastrophizing pain scores were collected.

RESULTS

After adjusting for all other variables, higher age and catastrophizing pain scores were associated with lower odds of postoperative opioid usage. Increasing age and BMI were associated with lower odds of being referred to pain management. There was no relationship between self-reported preoperative pain tolerance and postoperative change in WOMAC or VAS pain scores.

CONCLUSIONS

This information may help surgeons advise their patients preoperatively and set expectations during the recovery period.

Rotational laxity and collateral ligament laxity following total knee arthroplasty with rotating platform

PURPOSE

The aim of this study was to evaluate laxity in knees with pre-operative (preop) valgus alignment compared to knees with pre-operative varus alignment after total knee arthroplasty (TKA).

METHODS

This was a retrospective study including 81 patients, with six years follow-up, for pre-operative valgus- or varus alignment of the leg. All patients had been supplied with the same cruciate retaining (CR) TKA with rotating platform. Clinical findings were assessed by KSS, OKS and IKDC 2000 score. Rotational knee laxity was evaluated by a validated instrument (Laxitester®) with 2 Nm torque in 30° flexion. Collateral ligament laxity was tested manually in 30° flexion with a bending moment of approximately 5 Nm. Biomechanical results were compared to the contralateral side.

RESULTS

Thirty-one patients had a preop valgus alignment of 8.96° and 50 patients a varus leg axis of 4.99° in the mean. In the preop valgus knees rotational analysis showed an increased laxity of 10.7° compared to preop varus knees (p = 0.001). There was no significant difference in medial (valgus 2.6 mm, varus 2.5 mm) and lateral (valgus 2.8 mm, varus 2.7 mm) laxity. KSS and OKS showed no significant differences in the follow-up results. In the IKDC 2000 objective score 50 % of the preop varus knees and 25.8 % of the preop valgus knees were classified as nearly normal. The difference in the IKDC objective was highly significant (p < 0.001).

CONCLUSION

Preop valgus knees show a significantly increased rotational laxity but no increased collateral ligament laxity compared to pre-operative varus knees six years after TKA with rotating platform. There is a significant difference in IKDC objective.

Normative Data for the Singapore English and Chinese SF-36 Version 2 Health Survey

Introduction: The aim of this study is to report normative data for the Short-Form 36 version 2 (SF-36v2) for assessing health-related quality of life, in the Singapore general population. Materials and Methods: Data for English and Chinese-speaking participants of the Singapore Prospective Study Programme were analysed. The SF-36v2 scores were norm-based with the English-speaking Singapore general population as reference and reported by age (in decades), gender and ethnicity as well as for the 5 most prevalent chronic medical conditions. Scores were reported separately for the English and Chinese language versions. Results: A total of 6151 English-speaking (61.5% Chinese and 19.2% Malay) and 1194 Chinese-speaking participants provided complete data. Mean (SD) age of all participants was 49.6 (12.58) years with 52.4% being women. In both languages, women reported lower scores than men on all scales. Among the chronic medical conditions, stroke had the largest impact on all English SF-36v2 scales and on 3 Chinese SF-36v2 scales (role-physical, general health and social functioning). Conclusion: We have provided detailed normative data for the Singapore English and Chinese SF-36v2, which would be valuable in furthering HRQoL research in Singapore and possibly the region. Key words: Health-related quality of life, Health status, Mental well-being, Social well-being

Younger patients report greater improvement in self-reported function after knee joint replacement

STUDY DESIGN

Retrospective chart review.

OBJECTIVES

To evaluate and compare the relationship between patients' age and the change in Oxford Knee Score from preoperative to postoperative assessments, and to investigate whether there is a relationship between preoperative Oxford Knee Score results and the indication for total knee replacement surgery, and if age affects this relationship.

BACKGROUND

An increasing number of younger patients receive knee joint replacements, yet it is unknown how this cohort functions after surgery. This warrants investigation into the potential age-related differences in joint function following surgery. The Oxford Knee Score has been validated as a clinical tool but has yet to be accepted in the decision-making process regarding the need for, or appropriateness of, total knee replacement.

METHODS

In a retrospective chart review, 240 patients completed the Oxford Knee Score questionnaire to evaluate chronic pain and/or dysfunction associated with the knee.

RESULTS

The largest improvement with joint replacement was observed to occur in the youngest patient group (50-59 years old). Moreover, the Oxford Knee Score was shown to be the strongest predictor (odds ratio = 0.61) for the indicated intervention when compared to other predictors. The youngest patient group reported a significantly (P<.03) higher Oxford Knee Score result when indicated for surgery, compared to the oldest patient group (80-89 years old).

CONCLUSION

The results provide insight into how age influences self-perceived joint function before and after joint replacement surgery, and into the clinical decision to provide the surgical option to younger patients. Moreover, the observed relationship between the Oxford Knee Score and the indicated treatment supports the use of the questionnaire as a preoperative tool in considering treatment options for patients with knee osteoarthritis.

LEVEL OF EVIDENCE

Prognosis, level 2b.

Determinants of pain, functional limitations and health-related quality of life six months after total knee arthroplasty: results from a prospective cohort study

Background

Total knee arthroplasty (TKA) is an effective procedure. However, for some patients, the outcomes are not satisfactory. Identification of TKA determinants could help manage these patients more efficiently. The purpose of this study was to identify pre- and perioperative determinants of pain, functional limitations and health-related quality of life (HRQoL) 6 months after TKA.

Methods

138 participants were recruited from 3 hospitals in Quebec City, Canada and followed up until 6 months after surgery. Data were collected through review of the subjects’ medical files and structured telephone interviews before and 6 months after TKA. Pain and functional limitations were measured with the Western Ontario and McMaster Osteoarthritis Index (WOMAC) and HRQoL was measured with the SF-36 Health Survey. Independent variables included demographic, socioeconomic, psychosocial, clinical and surgical characteristics of participants as well as data on health services utilization. Stepwise multiple regression analysis was used to assess the strength of the associations between the independent variables and the WOMAC and SF-36 scores.

Results

Higher preoperative pain, cruciate retaining implants and the number of complications were significantly associated with worse pain 6 months after TKA (p < 0.05) and explained 11% of the variance of the WOMAC pain score. Higher preoperative functional limitations, being single, separated, divorced or widowed, being unemployed or retired and the number of complications were significantly associated (p < 0.05) with worse functional limitations 6 months after TKA and explained 16% of the variance of the WOMAC function score. Lower preoperative HRQoL, contralateral knee pain, higher psychological distress and comorbidities were significantly associated (p < 0.05) with worse HRQoL 6 months after TKA and explained 23% of the variance of the SF-36 physical functioning score.

Conclusions

Several variables were found to be significantly associated with worse outcomes 6 months after TKA and may help identify patients at risk of poorer outcome. The identification of these determinants could help manage patients more efficiently and may help target patients who may benefit from extensive rehabilitation.