Variations In Good Patient Reported Outcomes After Total Knee Arthroplasty

Can the minimal clinically important difference (MCID) for the Oxford score, KOOS and its derivatives be identified in a French sample of total knee arthroplasties?

CONTEXT

To assess the effect of a surgical procedure on a patient, it is conventional to use clinical scores before and after the procedure, but it is increasingly common and recommended to weight the results of these scores with the notion of minimal clinically important difference ("MCID"). This MCID should be determined using either the data distribution method based on score variation, or the anchor method, which uses an external question to categorize the results. MCIDs vary from one population to another, and to our knowledge there has been no investigation in France for total knee arthroplasties (TKAs). We therefore conducted a prospective study on a population of TKAs in order to: 1) Define MCID in France on a population of TKAs for the Oxford score, KOOS (Knee injury and Osteoarthritis Outcome Score) and its derivatives, 2) Determine whether MCID for these scores in France is comparable to results in the literature.

HYPOTHESIS

Is the MCID for total knee arthroplasty in France comparable to other results in the literature?

MATERIAL AND METHOD

This was a prospective observational study in which 218 patients (85 men, 133 women) with a mean age of 72 years [27-90] who had undergone a primary TKA out of 300 initially included responded, before and after surgery, to the Oxford-12, KOOS and Forgotten Joint Score (FJS) questions (mean follow-up 24 months). MCID was calculated using the distribution method as well as the anchor method ("improvement 1 to 5" and "improvement yes or no").

RESULTS

At a mean follow-up of 24 months [18-36], the Oxford-12 score increased from 16 ± 8 [0-41] to 34 ± 11 [6-48] (p < 0.001), all components of the KOOS score were improved and the FJS at follow-up was 47 ± 32 [0-100]. For the anchor "improvement 1 to 5", there were 14 unimproved patients, 23 patients in identical condition and 179 patients improved by surgery. For the anchor "are you improved yes/no", there were 8 unimproved patients, 22 in identical condition and 187 surgically-improved patients. The mean MCID for all methods (anchor method and distribution) was 10 [7-13] for Oxford-12, 12 [12-12] for KOOS Symptom, 14 [12-17] for KOOS Pain, 12 [11-14] for KOOS Function, 14 [12-16] for KOOS Sport, 15 [15-16] for KOOS Quality of Life (QOL), 11 [10-12] for KOOS 12, 15 [12-18] for KOOS 12 Pa in. 12 [12-13] for KOOS 12 Function, 15 [15-15] for KOOS 12 QOL, 14 [13-14] for KOOS Physical Function Short-form (PS) and 14 [13-16] for KOOS Joint Replacement (JR).

DISCUSSION

The MCID for the Oxford-12, KOOS and its derivatives scores in a French population is comparable to that observed in other populations in the literature.

LEVEL OF EVIDENCE

IV; prospective study without control group.

Patient-Reported Outcomes Following Periprosthetic Joint Infection of the Hip and Knee: A Longitudinal, Prospective Observational Study

BACKGROUND

The role of patient-reported outcome measures (PROMs) as tools for monitoring the impact and outcomes of periprosthetic joint infection (PJI) is not well described. This study analyzed the Oxford Hip Score (OHS) or Oxford Knee Score (OKS) in a prospective observational cohort of patients with hip or knee PJI.

METHODS

The PIANO (Prosthetic joint Infection in Australia and New Zealand, Observational study) cohort prospectively enrolled patients with newly diagnosed PJI from multiple centers. The OHS and OKS were evaluated at PJI diagnosis (baseline) and at 3, 12, and 24 months. Scores and score changes were examined according to PJI type, patient characteristics, and management. A successful functional outcome at 12 months was defined as an OHS of >38 or OHS of >36 and/or an improvement from baseline of >12 or >9, respectively.

RESULTS

Of the 741 participants, PROMs were available at 12 months for 233 with hip and 342 with knee PJI. Significant improvements (p < 0.0001) were seen at 12 months for both the OHS (24.5 to 36) and OKS (25 to 34), with no further improvement at 24 months. Patients with late-acute PJI had a higher median baseline OHS (35; interquartile range [22 to 46]) and OKS (30 [18 to 41]) than those with early PJI (OHS: 19 [15 to 29]; OKS: 22 [16 to 29.5]) or chronic PJI (OHS: 23 [14 to 34]; OKS 22 [14 to 28]). Logistic regression showed that a clinical cure (adjusted odds ratio [aOR] = 1.88, 95% confidence interval [CI] = 1.28 to 2.76, p = 0.001) and early PJI (aOR = 2.56, 95% CI = 1.64 to 4.07, p < 0.0001) independently predicted a successful functional outcome. Chronic renal impairment (aOR = 0.31, 95% CI = 0.13 to 0.71, p = 0.007), congestive cardiac failure (aOR = 0.41, 95% CI = 0.17 to 0.95, p = 0.04), and clinical signs of inflammation (aOR = 0.53, 95% CI = 0.33 to 0.85, p = 0.009) at diagnosis independently predicted failure to achieve a successful functional outcome.

CONCLUSIONS

The OHS and OKS varied significantly at baseline and 12 months according to PJI type, emphasizing the need to consider the PJI type when evaluating treatment success. This study highlights superior functional outcomes associated with early PJI and with achievement of a clinical cure.

LEVEL OF EVIDENCE

Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Modelled cost-effectiveness analysis of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual care

BACKGROUND

The aim of the study was to estimate the long-term cost-effectiveness of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual postoperative care.

METHODS

Study design: A decision-analytic (cohort Markov) model was used for the simulation with time dependent annual transition probabilities and a time horizon of five years.

SETTING

Patients treated by National Health Service (NHS) hospitals in England and Wales.

STUDY POPULATION

Adults classified as having chronic pain three months after undergoing a total knee replacement.

INTERVENTION

The STAR care pathway following a total knee replacement.

COMPARATOR

Usual postoperative care following a total knee replacement.

PERSPECTIVE

The study was undertaken from the perspective of the NHS.

OUTCOME MEASURES

Quality-adjusted life years and healthcare costs. Discounting: A rate of 3.5% for both costs and health utility.

RESULTS

Model results indicate that the STAR intervention would dominate current practice by providing a gain in quality-adjusted life years (QALYs) of 0.086 and a reduction of £375 (per person) in costs over the first five years. The incremental net monetary benefit of the STAR intervention was estimated at £2,086 (at a threshold of £20,000 per QALY). Probabilistic sensitivity analysis suggests the STAR intervention is likely to be cost-effective with a probability of 0.62. The results remain robust to changes in model assumptions on comparator utility and the timing of the start of the intervention. If hospital admission costs are assumed not to be reduced by the STAR intervention, it would no longer be cost saving, but it would likely be cost-effective based on probabilistic sensitivity analysis (0.59).

CONCLUSION

Evidence from the economic model suggests that the STAR care pathway is likely to be cost-effective and potentially dominant from an NHS perspective.

TRIAL REGISTRATION

The STAR trial is registered with ISRCTN, ISRCTN92545361.

Posterior cruciate-retaining total knee arthroplasty exhibits small kinematic changes in the first postoperative year

PURPOSE

Fluoroscopic knee kinematics have historically been quantified at least 1 year after total knee arthroplasty (TKA). The purpose of this study was to longitudinally assess knee kinematics at 6-12 weeks, 6 months, and 1 year after TKA to determine if earlier evaluation may be justified.

METHODS

Twenty-one patients participated after undergoing TKA with a posterior cruciate ligament-retaining fixed-bearing prosthesis. Fluoroscopic examinations of lunge, kneel, and step-up activities were performed at 12 ± 4 weeks (V1), 7 ± 2 months (V2), and 13 ± 2 months (V3) postoperatively. Images were analyzed using a three-dimensional to two-dimensional image registration technique. Maximum flexion poses for lunging and kneeling were compared between visits with repeated-measures statistical tests. For the step-up activity, mixed-effects linear models were constructed for condylar anteroposterior (AP) contact points and tibial internal rotation throughout flexion. Estimated marginal means of fitted values were plotted with 95% confidence intervals and used to compare mean kinematics between visits.

RESULTS

There were no significant changes in maximum lunging flexion over time (p = 0.405), though significant increases in maximum kneeling flexion were observed between V1 (106 ± 8°) and V2 (110 ± 9°) (p = 0.006), and V1 and V3 (113 ± 9°) (p = 0.0003). While statistical differences were calculated for lunging medial condyle AP translation and kneeling tibial internal rotation, absolute differences in condylar AP contact locations were less than ~ 2 mm between all visits during both movements. For the step-up activity, tibial internal rotation increased with flexion, and there were pair-wise significant differences at all flexion angles between V1-V2 (p < 0.001) and V1-V3 (p < 0.001). Anterior medial condylar translation was observed with flexion, with pair-wise significant differences present for V1-V3 (p = 0.005) and V2-V3 (p < 0.001). The lateral condyle exhibited initial posterior translation followed by anterior translation with increasing flexion, with pair-wise differences between all visits (p < 0.005 for all comparisons).

CONCLUSION

Though statistical differences were observed between visits for all activities, variations in estimated mean condylar positions were within ~ 2 mm from ~ 12 weeks to 1 year. Considering measurement error averages approximately 1 mm for sagittal plane translations, these results indicate that knee kinematics during kneel, lunge, and step-up activities may be sustained from as early as 12 weeks after TKA.

Decision regret after primary hip and knee replacement surgery

BACKGROUND

Decision regret (DR) is a recognised patient centered outcome measure following a therapeutic intervention. This study aimed to measure DR following primary total hip and knee arthroplasty (THA/TKA), to assess for differences between these patients and explore possible contributory factors.

METHOD

DR was measured using the DR scale in a group of THA and TKA patients, between February 2017 and December 2018, who had made a decision to have joint replacement surgery within the previous year and were able to reflect on their outcomes.

RESULTS

On analysis a significantly greater proportion of TKA patients reported moderate or severe (Mod/Sev) DR [17.1% (56/328)] compared to THA patients [4.8% (18/376)]. Conversely, a significantly reduced proportion of TKA patients reported having No DR [42.1% (138/328)] compared to THA patients [66.7% (251/376)]. On multivariate logistic regression analysis joint replacement type (TKA/THA) and change in Oxford score were significant predictors of DR with gender, age, BMI and ASA grade not significantly associated. TKA patients were more than twice as likely to have Mod/Sev DR compared THA patients (Odds Ratio = 2.33 (95% CI 1.24-4.39)). Patients with poorer improvements in pain and function 1-year post-operatively (measured by Oxford scores) reported greater levels of DR.

CONCLUSION

TKA patients were significantly more likely to report greater levels of DR 1-year following surgery compared to THA patients. For both TKA and THA patients, greater levels of DR were associated with poorer Oxford scores. The use of decision aids to reduce post-operative DR in joint replacement patients should be examined especially for knee replacement patients.

Effect of Weight Change on Patient-Reported Outcomes Following Total Joint Arthroplasty

BACKGROUND

Increased body mass index (BMI) has been previously described as a risk factor for complications after total joint arthroplasty (TJA); however, its effect on patient-reported outcomes has not been thoroughly investigated. This study examines the effect of postoperative weight change on the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) scores for total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients.

METHODS

A retrospective review of 988 patients undergoing THA or TKA was performed. PROMIS-PF scores and BMI were recorded throughout the study duration. Patients were classified by a 5% change in BMI. A univariate analysis evaluated differences across groups. Mixed-effect models evaluated predictors of change in functional score over the postoperative follow-up time.

RESULTS

43.1% patients had a THA and 56.9% patients had a TKA. At 0 to 3 months, 92% of patients had no change in BMI, 3 to 6 months 82% had no change, and 6 to 12 months 80% had no change. There were no significant demographic or comorbidity differences across groups for both THA and TKA. Similar improvements in PROMIS-PF scores were observed across weight change groups. In the mixed-effect models, postoperative time was found to be a significant predictor of postoperative PF score. Both THA and TKA patients saw greater improvements in PROMIS-PF scores in patients with lower preoperative BMIs.

CONCLUSION

These results demonstrate most patients do not experience substantial changes in weight following TJA. However, lower BMIs at the time of surgery were associated with an increased functional improvement. Therefore, efforts to optimize BMI should be focused preoperatively to improve surgical outcomes.

Defining the minimal clinically important difference for the knee society score following revision total knee arthroplasty

BACKGROUND

No previous study has evaluated the MCID for revision total knee arthroplasty (TKA). This study aimed to identify the MCID for the Knee Society Score (KSS), for revision TKA.

METHODS

Prospectively collected data from 270 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively, at 6 months and 2 years using Knee Society Function Score (KSFS) and Knee (KSKS) Scores, and Oxford Knee Score (OKS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in OKS ≥ 5, patient satisfaction, and implant survivorship following revision TKA.

RESULTS

The cohort comprised 70% females, with mean age of 69.0 years, that underwent unilateral revision TKA. The MCID determined by anchor-based linear regression method using OKS was 6.3 for KSFS, and 6.6 for KSKS. The MCID determined by anchor-based ROC was between 15 and 20 for KSFS (AUC: satisfaction = 71.8%, survivorship = 61.4%) and between 33 and 34 for KSKS (AUC: satisfaction = 76.3%, survivorship = 67.1%). The MCID determined by distribution-based method of 0.5 SD was 11.7 for KSFS and 11.9 for KSKS.

CONCLUSION

The MCID of 6.3 points for KSFS, and 6.6 points for KSKS, is a useful benchmark for future studies looking to compare revision against primary TKA outcomes. Clinically, the MCID between 15 and 20 for KSFS and between 33 and 34 for KSKS is a powerful tool for discriminating patients with successful outcomes after revision TKA. Implant survivorship is an objective and naturally dichotomous outcome measure that complements the subjective measure of patient satisfaction, which future MCID studies could consider utilizing as anchors in ROC.

LEVEL OF EVIDENCE

II.

The influence of obesity on achievement of a 'forgotten joint' following total knee arthroplasty

INTRODUCTION

Obesity has been associated with poorer outcomes following total knee arthroplasty (TKA); however, data remain sparse on its impact on patients' joint awareness following surgery. This study aims to investigate the impact of body mass index (BMI) on improvement in outcomes following TKA as assessed by the Forgotten Joint Score-12 (FJS-12).

MATERIALS AND METHODS

We retrospectively reviewed 1075 patients who underwent primary TKA from 2017 to 2020 with available postoperative FJS-12 scores. Patients were stratified based on their BMI (kg/m²): < 30, 30.0-34.9 (obese class I), 35.0-39.9 (obese class II), and ≥ 40 (obese class III). FJS-12 and KOOS, JR scores were collected at various time points. Demographic differences were assessed with Chi-square and ANOVA tests. Mean scores between BMI groups were compared using univariate ANCOVA, controlling for observed demographic differences.

RESULTS

Of the 1075 patients included, there were 457 with a BMI < 30, 331 who were obese class I, 162 obese class II, and 125 obese class III. There were no statistical differences in FJS-12 scores between the BMI groups at 3 months (27.24 vs. 25.33 vs. 23.57 vs. 22.48; p = 0.99), 1 year (45.07 vs. 41.86 vs. 40.51 vs. 36.22; p = 0.92) and 2 years (51.31 vs. 52.86 vs. 46.17 vs. 44.97; p = 0.94). Preoperative KOOS, JR scores significantly differed between the various BMI categories (49.33 vs. 46.63 vs. 44.24 vs. 39.33; p < 0.01); however, 3-month (p = 0.20) and 1-year (p = 0.13) scores were not statistically significant. Mean improvement in FJS-12 scores from 3 months to 2 years was statistically greatest for obese class I patients and lowest for obese class III patients (24.07 vs. 27.53 vs. 22.60 vs. 22.49; p = 0.01). KOOS, JR score improvement from baseline to 1 year was statistically greatest for obese class III patients and lowest for non-obese patients (22.34 vs. 25.49 vs. 23.77 vs. 27.58; p < 0.01).

CONCLUSION

While all groups demonstrated postoperative improvement, those with higher BMI reported lower mean FJS-12 scores but these differences were not found to be significant. Our study showed no significant impact of BMI on postoperative joint awareness, which implies that obese patients, in all obesity classes, experience similar functional improvement following TKA.

LEVEL III EVIDENCE

Retrospective Cohort Study.

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.

Which Pre- and Postoperative Coronal Plane Laxity Parameters Influence Patient Satisfaction and Function after Primary Total Knee Arthroplasty?

Soft tissue balancing, while accepted as crucial to total knee arthroplasty (TKA) outcomes, is incompletely defined as the subject of broad recommendations. We analyzed 120 computer-assisted, posterior stabilized TKA undertaken for osteoarthritis. Coronal plane laxity was measured, in the 91 varus and 29 valgus knees, prior to any bone resection or soft tissue release, and again after implant insertion. Soft tissue laxity parameters were correlated to the American Knee Society Score (2011) at a minimum follow-up of 12 months with a focus on patient function and satisfaction. Thirteen specific laxity parameters showed a significant correlation to satisfaction, one parameter correlated to function, and another to both functional and satisfaction outcomes. Most correlations were weak, the strongest related to postoperative decreases in coronal plane laxity. Greater preoperative varus but not valgus deformity was associated with higher satisfaction scores. Additionally, 30 patients who reported 40 of 40 satisfaction and that their TKA knee felt normal at all times did not have soft tissue balancing parameters distinguishing them from other subjects. Patient satisfaction and function outcomes demonstrated limited correlation to coronal plane soft tissue parameters. It appears that optimizing TKA satisfaction and function is not as simple as producing a narrow range of coronal laxity parameters. The ongoing debate around optimal coronal plane alignment and its subsequent effect on coronal plane soft tissues may not be as independently important as currently argued. Soft tissue balance may need to be considered as a more complex global envelope.

The oxford knee score minimal clinically important difference for revision total knee arthroplasty

BACKGROUND

Minimal clinically important difference (MCID) is crucial for interpreting meaningful improvements in patient-reported outcome measures (PROMs). No previous study has evaluated the MCID for the Oxford Knee Score (OKS) in revision total knee arthroplasty (TKA). This study aimed to propose the OKS MCID for revision TKA.

METHODS

Prospectively collected data from 191 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively and at 2 years using OKS and Short-Form 36 Physical Component Score (SF-36 PCS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in SF-36 PCS ≥ 12, patient satisfaction, and implant survivorship following revision TKA.

RESULTS

The MCID determined by anchor-based linear regression method using improvements in SF-36 PCS was 4.9 points. The MCID determined by anchor-based ROC was 10.5 points for satisfaction (AUC = 74.8%) and 13.5 points for implant survivorship (AUC = 73.7%). The MCID determined by distribution-based method of 0.5 SD was 4.7.

CONCLUSION

The proposed MCID for OKS following revision TKA is 4.9 points. Patients who achieve an improvement in OKS of at least 10.5-13.5 points by 2 years are likely to be satisfied with their surgery and not require a subsequent re-revision TKA. Patients undergoing revision TKA should aim for an improvement in OKS of at least 10.5-13.5 points as a target score.

Can Met Expectations Moderate the Relationship Between Pain/Function and Satisfaction in Total Knee Arthroplasty?

BACKGROUND

Approximately 20% of patients are dissatisfied with their total knee arthroplasty (TKA) at 1-year post-surgery. Met expectations have been found by some to significantly predict satisfaction. The role of met expectations in determining patient satisfaction has not been exhaustively explored. The primary aim of this study is to evaluate if met expectations moderate the relationship between pain and function variables and satisfaction.

METHODS

Patients who underwent primary TKA for osteoarthritis were included in the study (n = 304). Patient-reported outcomes at pre-surgery and 1-year post-surgery were collected. The Knee Society Score (KSS) satisfaction subscale was used as the dependent variable. Candidate independent variables included the following: demographics, KSS, Knee injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Self-Administered Comorbidity Questionnaire, and University of California Los Angeles activity score. Separate linear regression models were created to test interactions for KSS met expectations with pain and KSS met expectations with function.

RESULTS

Significant predictors of satisfaction were KSS symptoms (pain), KOOS activities of daily living (function), KSS met expectations, KOOS pre-surgery activities of daily living, body mass index, and SF-12 general health. A significant interaction between met expectations and pain was found (P = .043) and the met expectations and function interaction approached significance (P = .086). For both interactions, as met expectations increased, pain and function predicted satisfaction less strongly.

CONCLUSION

Met expectations were found to moderate the relationship between pain and satisfaction. There may be more value in improving pain for patients with low met expectations.

LEVEL OF EVIDENCE

Level IV.

Perioperative Systemic Dexamethasone Reduces Length of Stay in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The objective of this review is to examine the effect of perioperative systemic corticosteroids at varying doses and timings on early postoperative recovery outcomes following unilateral total knee and total hip arthroplasty. The primary outcome was length of stay (LOS).

METHODS

A systematic review and meta-analysis of randomized controlled trials was performed. MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to June 1, 2020. Studies comparing the outcome of adult patients receiving a systemic steroid to patients who did not receive steroids were included.

RESULTS

Seventeen studies were included, incorporating 1957 patients. Perioperative corticosteroids reduced hospital LOS (mean difference [MD] = -0.39 days, 95% confidence interval [CI] -0.61 to -0.18). A subsequent dose of corticosteroid at 24 hours further reduced LOS (MD = -0.33, 95% CI -0.55 to -0.11). Corticosteroids resulted in reduced levels of pain on postoperative day (POD) 0 (MD = -1.99, 95% CI -3.30 to -0.69), POD1 (MD = -1.47, 95% CI -2.15 to -0.79), and POD2. Higher doses were more effective in reducing pain with activity on POD0 (P = .006) and 1 (P = .023). Steroids reduced the incidence of PONV on POD1 (log odds ratio [OR] = -1.05, 95% CI -1.26 to -0.84) and POD2, with greater effect at higher doses (P = .046). Corticosteroids did not increase the incidence of infection (P = 1.000), venous thromboembolism (P = 1.000), or gastrointestinal hemorrhage (P = 1.000) but were associated with an increase in blood glucose (MD = 5.30 mg/dL, 95% CI 2.69-7.90).

CONCLUSION

Perioperative corticosteroids are safe, facilitate earlier discharge, and improve patient recovery following unilateral total knee arthroplasty and total hip arthroplasty. Higher doses (15-20 mg of dexamethasone) are associated with further reductions in dynamic pain and PONV, and repeat dosing may further reduce LOS.

Age stratified, matched comparison of unicompartmental and total knee replacement

BACKGROUND

Unicompartmental knee replacement (UKR) tends to provide better function but has a higher revision rate than total knee replacement (TKR). The aim was to determine if this occurred in all age groups.

METHODS

Two large, non-registry, prospective cohorts with median 10-year follow-up (2252 TKR, 1000 medial UKR) were identified. All UKR met recommended indications. TKR with an inappropriate disease pattern for medial UKR were excluded. Knees were propensity score-matched within age-strata (<60 years at operation, 60 to <75, 75+) and compared using Oxford Knee Score (OKS), Kaplan-Meier revision rates and a composite failure, defined as any of revision, reoperation or no improvement in OKS.

RESULTS

One thousand five hundred and eighty-two TKR and UKR were matched. Results are reported TKR vs UKR for ages <60, 60 to <75 and 75+. Median 10-year OKS were 33 vs 45 (p < 0.001), 36 vs 42 (p < 0.001) and 36 vs 38 (p = 0.25). Ten-year revision rates were 11% vs 7%, 5% vs 5%, and 5% vs 10%, (none significant). The composite failures occurred 8%, 5% and 5% more frequently with TKR than UKR (none significant).

CONCLUSIONS

In this matched study UKR provided better functional outcomes in all age groups, particularly the young, and provided substantially more excellent outcomes. Although in older groups TKR tended to have a lower revision rate, in the young UKR had a lower revision rate. This was surprising and was perhaps because in this study UKR was, as recommended, only used for bone-on-bone arthritis, whereas in young patients it is widely used for early arthritis, which is associated with a high failure rate. This study supports the use of UKR with recommended indications, in all age groups.

The use of patient-reported outcome measures to guide referral for hip and knee arthroplasty

AIMS

To calculate how the likelihood of obtaining measurable benefit from hip or knee arthroplasty varies with preoperative patient-reported scores.

METHODS

Existing UK data from 222,933 knee and 209,760 hip arthroplasty patients were used to model an individual's probability of gaining meaningful improvement after surgery based on their preoperative Oxford Knee or Hip Score (OKS/OHS). A clinically meaningful improvement after arthroplasty was defined as ≥ 8 point improvement in OHS, and ≥ 7 in OKS.

RESULTS

The upper preoperative score threshold, above which patients are unlikely to achieve any meaningful improvement from surgery, is 41 for knees and 40 for hips. At lower scores, the probability of improvement increased towards a maximum of 88% (knee) and 95% for (hips).

CONCLUSION

By our definition of meaningful improvement, patients with preoperative scores above 41 (OKS) and 40 (OHS) should not be routinely referred to secondary care for possible arthroplasty. Using lower thresholds would incrementally increase the probability of meaningful benefit for those referred but will exclude some patients with potential to benefit. The findings are useful to support the complex shared decision-making process in primary care for referral to secondary care; and in secondary care for experienced clinicians counselling patients considering knee or hip arthroplasty, but should not be used in isolation. Cite this article: Bone Joint J 2020;102-B(7):941-949.

Minimal clinically important difference of commonly used patient-reported outcome measures in total knee arthroplasty: review of terminologies, methods and proposed values

Purpose

The aim of this article was to highlight various terminologies and methods of calculation of minimal clinically important difference (MCID) and summarize MCID values of frequently used patient-reported outcome measures (PROMs) evaluating total knee arthroplasty (TKA).

Materials and methods

PubMed and EMBASE databases were searched through May 2019. Of 71 articles identified, 18 articles matched and underwent a comprehensive analysis for terminologies used to indicate clinical significance, method of calculation, and reported MCID values.

Results

MCID was the most common terminology (67% studies) and anchor-based methods were most commonly employed (67% studies) to calculate it. The analytical methods used to calculate and the estimated values of MCID for clinical use are highly variable. MCID values reported for WOMAC scores are 20.5 to 36.0, 17.6 to 33.0 and 12.9 to 25.0 for pain, function and stiffness sub-scales, respectively, and 4.7 to 10.0 for OKS.

Conclusion

There was lack of standardization in the methodology employed to calculate MCID in the available studies. MCID values reported in this review could be used for patients undergoing TKA, although caution is advised in their interpretation and application.

Do dissatisfied patients have unrealistic expectations? A systematic review and best-evidence synthesis in knee and hip arthroplasty patients

End-stage osteoarthritis is commonly treated with joint replacement. Despite high clinical success rates, up to 28% of patients are dissatisfied with the outcome.

This best-evidence synthesis aimed to review studies with different forms of study design and methodology that examined the relationship between (fulfilment of) outcome expectations of hip and knee patients and satisfaction with outcome.

A literature search was performed in PubMed, Web of Science, PsycInfo, Cochrane, and Google Scholar to identify studies conducted up to November 2017. The methodological quality of studies was assessed using the Newcastle-Ottawa Scale.

In this best-evidence synthesis systematic review, the following main results could be seen. In only half of all studies were preoperative expectations associated with level of satisfaction, while in almost all studies (93%), fulfilment of expectations was related to satisfaction. The effect of met expectations did not differ between hip and knee patients or study design.

Fulfilment of expectations seems to be consistently associated with patient satisfaction with outcome. Emphasis in future research must be placed on the operationalization and measurement of expectations and satisfaction to determine the (strength of the) influence of these different forms of assessment on the (existence of the) relationship.

Cite this article: EFORT Open Rev 2020;5:226-240. DOI: 10.1302/2058-5241.5.190015

[Predictors for persistent pain and dissatisfaction after total knee arthroplasty]

BACKGROUND

A substantial number of patients patients suffer from persistent pain or are unsatisfied after total knee arthroplasty (TKA).

OBJECTIVES

This work aims to present the frequency of postoperative persistent pain and/or dissatisfaction as well as known causes and predictors.

MATERIALS AND METHODS

The current literature is studied regarding the subject and is reviewed narratively.

RESULTS

Most postoperative problems did not arise from operation details, but from patient-related criteria, a lack of patient education and selection. The satisfaction correlates most strongly with the reduction of preoperative pain.

CONCLUSION

For a successful TKA, care should be taken that the following aspects are met preoperatively: clinically and radiologically advanced osteoarthritis, a patient age preferably older than 60 years, sufficient psychosocial resources to cope with postoperative stress, no opioid medication and realistic expectations after TKA. Postoperatively, patients with persistent pain or dissatisfaction should be checked for any prosthesis-related problems. If no prosthesis-related problems could be detected, the patients should be referred for interdisciplinary therapies.

Does Hospital Consumer Assessment of Healthcare Providers and Systems survey correlate with traditional metrics of patient satisfaction? The challenge of measuring patient pain control and satisfaction in total joint replacement

Background

Medicare reimbursements have been tied to patient satisfaction measures. Despite these measures' influence on reimbursements, the relationship between pain management and patient satisfaction remains unclear. This study aims to evaluate the relationship between traditional patient perception of pain control and their overall satisfaction after joint replacement.

Methods

This study is a retrospective review of consecutive primary total hip and total knee replacements. A total of 286 patients who underwent primary total hip (N = 106) and total knee (N = 196) replacements with completed Hospital Consumer Assessment of Healthcare Providers and Systems surveys were evaluated. Pain control, communication, and hospital satisfaction were stratified into satisfactory or unsatisfactory groups. These 2 groups were compared in terms of visual analog scale (VAS), opioid use in morphine equivalents, length of hospital stay, anesthesia type, and demographics.

Results

Average VAS and opioid use did not differ between patient groups for any of the questions evaluated. Those who responded “always” to pain domain questions had a statistically shorter length of stay compared to patients with other response. On average, those who endorsed “always” on communication question were younger.

Conclusions

Patients who endorsed satisfactory pain control and communication with staff had shorter lengths of stay. There was no relationship between survey scores and traditional pain control measures such as VAS and opioid use. This questions the relevance of our primary pain measures in assessing patient perception of pain control. Length of stay may be a better surrogate marker for patient satisfaction of pain control.

Larger range of motion and increased return to activity, but higher revision rates following unicompartmental versus total knee arthroplasty in patients under 65: a systematic review

PURPOSE

Due to the lack of comparative studies, a systematic review was conducted to determine revision rates of unicompartmental and total knee arthroplasty (UKA and TKA), and compare functional outcomes, range of motion and activity scores in patients less than 65 years of age.

METHODS

A literature search was performed using PubMed, Embase, and Cochrane systems since 2000. 27 UKA and 33 TKA studies were identified and included. Annual revision rate (ARR), functional outcomes, and return to activity were assessed for both types of arthroplasty using independent t tests.

RESULTS

Four level I studies, 12 level II, 16 level III, and 29 level IV were included, which reported on outcomes in 2224 UKAs and 4737 TKAs. UKA studies reported 183 revisions, yielding an ARR of 1.00 and extrapolated 10-year survivorship of 90.0%. TKA studies reported 324 TKA revisions, resulting in an ARR of 0.53 and extrapolated 10-year survivorship of 94.7%. Functional outcomes scores following UKA and TKA were equivalent, however, following UKA larger ROM (125° versus 114°, p = 0.004) and higher UCLA scores were observed compared to TKA (6.9 versus 6.0, n.s.).

CONCLUSION

These results show that good-to-excellent outcomes can be achieved following UKA and TKA in patients less than 65 years of age. A higher ARR was noted following UKA compared to TKA. However, improved functional outcomes, ROM and return to activity were found after UKA than TKA in this young population. Comparative studies are needed to confirm these findings and assess factors contributing to failure at the younger patient population. Outcomes of UKA and TKA in patients younger than 65 years are both satisfying, and therefore, both procedures are not contraindicated at younger age. UKA has several important advantages over TKA in this young and frequently more active population.

LEVEL OF EVIDENCE

IV.

Construct validation and correlates of preoperative expectations of postsurgical recovery in persons undergoing knee replacement: baseline findings from a randomized clinical trial

Background

A patient’s recovery expectations prior to knee arthroplasty influence postsurgical outcome and satisfaction but a unidimensional measure of expectation has not been reported in the literature. Our primary purpose was to determine the extent to which a patient expectations scale reflects a unidimensional construct. Our second purpose was to identify pre-operative variables associated with patients’ expectations. We hypothesized that previously identified predictors of the latent expectation scale score would be associated with expectations and that previously unexplored variables of pain catastrophizing, depressive and anxiety symptoms, self-efficacy and number of painful body regions would also associate with pre-operative expectations.

Methods

Our randomized clinical trial had 384 patients assessed prior to knee replacement surgery. The expectations scale along with several predictor variables including WOMAC, psychological distress, and sociodemographic variables were obtained. Confirmatory factor analysis tested the unidimensionality of the measure and structural equation modeling identified predictors of the latent expectations measure.

Results

The expectations scale was found to be unidimensional with superior model fit (χ2 = 1.481; df = 2; p = 0.224; RMSEA = 0.035; 90% CI = [0–0.146]; CFI = 0.999; TLI = 0.993). The only variable significantly associated with expectations in the multivariate model was self-efficacy.

Conclusions

The expectations scale used in our study demonstrated unidimensionality and has strong potential for clinical application. Poor self-efficacy is a potential target for intervention given its independent association with expectation. Addressing expectations directly and indirectly through self-efficacy assessment may assist in better aligning patient’s expectations with likely outcome.

Trial registration

ClinicalTrials.gov NCT01620983.

Predictive values of WOMAC, KOOS, and SF-12 score for knee arthroplasty: data from the OAI

PURPOSE

A number of validated scores are available to monitor clinical outcome after knee arthroplasty. The current study examines whether WOMAC, KOOS, or SF-12 scores have a predictive value to identify patients that require total knee arthroplasty within 1 year.

METHODS

The Osteoarthritis Initiative includes 4684 patients in two groups: incidence subcohort (Group A, n = 3284) and progression subcohort (Group B, n = 1400). A total of 278 patients reached the endpoint "unilateral knee replacement" (Group A = 96; Group B = 182). WOMAC, KOOS, and SF-12 scores at the maximum of 12 months prior to surgery were used to analyse predictive values. ROC analysis and the diagnostic accuracy for these scores were reported.

RESULTS

Group A: WOMAC and KOOS score as well as the "physical component summary" of SF-12 showed an area under the curve (AUC) between 0.8 and 0.9 (high diagnostic evidence) to predict total knee replacement. The KOOS "symptoms" (0.67) and SF12 "function" (0.79) showed lower values. The KOOS QoL score showed the highest predictive value with an AUC of 0.84 (CI 95% 0.77-0.91, p < 0.001) resulting in a sensitivity of 0.88 and a specificity of 0.72. Similar numbers were achieved by the total WOMAC score with an AUC of 0.85 (CI 95% 0.82-0.88, p < 0.001) resulting in a sensitivity of 0.77 and a specificity of 0.82. The SF-12 physical component score had an AUC of 0.83 (CI 95% 0.79-0.87, p < 0.001) resulting in a sensitivity of 0.87 and a specificity of 0.68. Different combinations of scores increase the positive likelihood ratio (up to 18) and specificity (up to 0.97). Group B scores showed lower AUCs, sensitivities and specificities.

CONCLUSIONS

Combinations of WOMAC, KOOS, or SF-12 scores accurately predict patients that require knee arthroplasty within 1 year. In addition to other clinical parameters (physical examination, radiographs), they can guide patient and surgeon during the treatment of arthritis of the knee.

LEVEL OF EVIDENCE

II.

Do foot & ankle assessments assist the explanation of 1 year knee arthroplasty outcomes?

OBJECTIVE

Whilst a number of risk factors for poor patient reported outcome measures (PROMs) following knee arthroplasty (KA) have been identified, unexplained variability still remains. The role of pre-operative foot and ankle status on such outcomes has not been investigated. The aim of this study was therefore to determine the association of clinical foot and ankle assessments with patient reported outcomes 1 year following KA.

DESIGN

One hundred and fifteen participants from the Clinical Outcomes in Arthroplasty Study (COASt), underwent detailed foot and ankle assessments at baseline, prior to KA (2012-2014) and were followed up for self-reported outcomes 1 year after surgery.

RESULTS

Thirty nine percent of subjects reported foot pain at baseline. Mean pre-operative Oxford Knee Score (OKS; 0 [worst] to 48 [best outcome]) was 21 and post-operative OKS score was 38. In fully adjusted analysis pre-operative foot pain was significantly associated with 1 year outcome (risk ratio [RR] 0.78 95% confidence interval [95% CI] 0.62, 0.98). No significant association was observed between ankle dorsiflexion or foot posture and outcome.

CONCLUSIONS

Patients with pre-operative foot pain are more likely to have poorer clinically important outcomes 1 year following KA than patients without foot pain. Static ankle dorsiflexion and foot posture do not further explain post-operative KA outcomes. Consideration should also be given to address pre-operative foot pain when attempting to achieve a good clinical outcome for KA.

Factors Predicting the Forgotten Joint Score After Total Knee Arthroplasty

BACKGROUND

We recently developed the forgotten joint score 12 (FJS-12), a tool to assess joint awareness in everyday life. It is unknown whether patient factors predicting the outcome of the FJS-12 after total knee arthroplasty (TKA) exist.

METHODS

Five hundred forty cases of TKA were analyzed. Objective clinical results were obtained for range of motion, stability, and alignment. Patient-reported outcome was assessed using the FJS-12. Baseline data and complications were recorded. Cluster analysis based on FJS-12, postoperative flexion, and age resulted in 3 groups: poor outcome (88 patients), good outcome (340 patients), and excellent outcome (118 patients). The characteristics of "poor" compared to "excellent" clusters were studied more closely using bivariate comparative tests and logistic regression.

RESULTS

We could find that male patients around 63 years with a lower body mass index were most likely to be allocated to the cluster "excellent" (defined as high FJS-12 and high postoperative flexion). Preoperative extension and flexion, stability, varus/valgus alignment, surgery prior TKA, or comorbidities were not predictive for the FJS-12 at 1 year follow-up.

CONCLUSION

We identified 3 preoperative patient-related factors that may predict the FJS-12 after TKA: body mass index, age, and gender. These findings can be used to guide decision-making and important preoperative discussions on expectations after TKA.

The effect of expectation on satisfaction in total knee replacements: a systematic review

Total knee replacement has reliably been shown to have a beneficial effect in knee osteoarthritis; however, around 17 % of patients are dissatisfied with the result. A commonly proposed mechanism driving the dissatisfaction rate is a discrepancy between expected and actual/perceived outcome. Our aim was to conduct a systematic review examining any association between pre-operative expectations and satisfaction. A comprehensive electronic search strategy was used to identify studies from MEDLINE, EMBASE, and the Cochrane Library from inception until May 2015. Data was extracted according to PRISMA guidelines and an online, published protocol. Four studies are included in this review. One study found an association between expectations and satisfaction. Different measures of expectation and satisfaction were used in all studies. To date, there is no consensus on how expectations or satisfaction should be measured, and a large number of studies that have the available information failed to conduct the relevant sub-group analysis. Further elucidation and consensus of how to measure expectations and satisfaction around joint replacement would aid this area of study greatly. On the basis of the current evidence it appears expectations have a small effect, if any, on satisfaction after knee replacement.