Knee Injury and Osteoarthritis Outcome Score Interpretation Thresholds at 3 and 12 Months After Arthroscopic Meniscal Surgery. What Changes, and What Stays the Same?

OBJECTIVE: To evaluate the change in minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) thresholds for the Knee injury and Osteoarthritis Outcome Score (KOOS) from 3 to 12 months following arthroscopic meniscus surgery. DESIGN: Retrospective cohort study. METHODS: We included patients from the Knee Arthroscopy Cohort Southern Denmark who had meniscus surgery between 2013 and 2015. We calculated the interpretation threshold values for MIC, PASS, and TF using an anchor-based adjusted predictive modeling method. Thresholds at 3 and 12 months postoperatively were compared to evaluate changes over time. RESULTS: The proportions of people who reported a clinically relevant improvement, or their symptoms being acceptable, increased by 10% to 15% points from 3 to 12 months after surgery. MIC thresholds for the 5 KOOS subscales remained stable from 3 to 12 months with statistically nonsignificant differences (95% confidence intervals) ranging from -0.3 (-3.0, 2.6) to -2.4 (-6.1, 1.3). All PASS thresholds except for quality of life (QOL) decreased by -6.5 (-11.8, -1.5) to -3.7 (-7.1, -0.4) points, indicating that higher symptom levels were accepted at 12 months. In contrast, the proportion reporting their treatment to have failed remained stable over time (19% and 17%). For QOL, a 7.4 (2.0, 13.2) higher TF threshold at 12 months suggested that improved QOL was required to not consider that the treatment had failed. CONCLUSION: More patients reported being improved at 1 year compared to at 3 months following meniscus surgery. The KOOS MIC thresholds were stable over time, whereas time-specific PASS values should be applied after meniscus surgery. J Orthop Sports Phys Ther 2023;53(11):685-702. Epub 3 October 2023. doi:10.2519/jospt.2023.11993.

Usage of guideline-adherent core treatments for knee osteoarthritis before and after consulting an orthopaedic surgeon: A prospective cohort study.

Objective: To describe 1) the proportion of patients with knee osteoarthritis (OA) undergoing guideline-adherent core treatments until six months after primary referral to an orthopaedic surgeon, 2) which specific treatment pathways these patients undertake and 3) the characteristics of patients choosing different treatment pathways. Design: This prospective cohort study consecutively invited patients referred to an orthopaedic surgeon due to knee OA at two Danish hospitals from October 2018 to December 2020. Before and six months after consulting the surgeon, patients answered a questionnaire reporting which treatments they had received for knee OA. The proportion receiving the combination of guideline-adherent treatments (i.e., exercise, education, and dietary weight management if needed) was determined. We evaluated the specific treatment usage before and until six months after the consultation and investigated characteristics of patients undertaking different pathways. Results: Out of 5251 eligible patients, 2574 (49%) had complete data and were included in analyses. 23% received guideline-adherent treatments, 10% had no treatment. Patients underwent 1143 unique treatment pathways, 62% including treatments not recommended/recommended against. Those who underwent guideline-adherent pathways had similar characteristics to those who did not but tended to be females, retired, had longer-lasting knee problems, have comorbidities, and higher education levels. Conclusions: Only one in four patients with knee OA received treatment adhering to clinical guidelines before and six months after consulting the surgeon. Patients used many different treatment pathways. There is a need for a structured effort to increase the use of guideline-adherent core treatments. Trial Identifiers: Registration: NCT03746184, Protocol: PMID: 34233992.

OPTIKNEE 2022: consensus recommendations to optimise knee health after traumatic knee injury to prevent osteoarthritis.

The goal of the OPTIKNEE consensus is to improve knee and overall health, to prevent osteoarthritis (OA) after a traumatic knee injury. The consensus followed a seven-step hybrid process. Expert groups conducted 7 systematic reviews to synthesise the current evidence and inform recommendations on the burden of knee injuries; risk factors for post-traumatic knee OA; rehabilitation to prevent post-traumatic knee OA; and patient-reported outcomes, muscle function and functional performance tests to monitor people at risk of post-traumatic knee OA. Draft consensus definitions, and clinical and research recommendations were generated, iteratively refined, and discussed at 6, tri-weekly, 2-hour videoconferencing meetings. After each meeting, items were finalised before the expert group (n=36) rated the level of appropriateness for each using a 9-point Likert scale, and recorded dissenting viewpoints through an anonymous online survey. Seven definitions, and 8 clinical recommendations (who to target, what to target and when, rehabilitation approach and interventions, what outcomes to monitor and how) and 6 research recommendations (research priorities, study design considerations, what outcomes to monitor and how) were voted on. All definitions and recommendations were rated appropriate (median appropriateness scores of 7-9) except for two subcomponents of one clinical recommendation, which were rated uncertain (median appropriateness score of 4.5-5.5). Varying levels of evidence supported each recommendation. Clinicians, patients, researchers and other stakeholders may use the definitions and recommendations to advocate for, guide, develop, test and implement person-centred evidence-based rehabilitation programmes following traumatic knee injury, and facilitate data synthesis to reduce the burden of knee post-traumatic knee OA.

Meaningful thresholds for patient-reported outcomes following interventions for anterior cruciate ligament tear or traumatic meniscus injury: a systematic review for the OPTIKNEE consensus.

OBJECTIVE: We synthesised and assessed credibility (ie, trustworthiness) of thresholds that define meaningful scores for patient-reported outcome measures (PROMs) following interventions for anterior cruciate ligament (ACL) tear or traumatic meniscus injury. DESIGN: Systematic review, narrative synthesis. DATA SOURCES: We searched five databases, handsearched references of included studies and tracked citations. ELIGIBILITY: Included studies investigated: individuals with ACL tear or meniscus injury; mean age <35 years; and PROM thresholds calculated using any method to define a minimal important change (MIC) or a meaningful post-treatment score (Patient Acceptable Symptom State (PASS) or Treatment Failure). RESULTS: We included 18 studies (15 ACL, 3 meniscus). Three different methods were used to calculate anchor-based MICs across 9 PROMs, PASS thresholds across 4 PROMs and treatment failure for 1 PROM. Credibility was rated 'high' for only one study-an MIC of 18 for the Knee injury and Osteoarthritis Outcome Score Quality-of-life (KOOS-QOL) subscale (using the MID Credibility Assessment Tool). Where multiple thresholds were calculated among 'low' credibility thresholds in ACL studies, MICs converged to within a 10-point range for KOOS-Symptoms (-1.2 to 5.4) and function in daily living (activities of daily living, ADL 0.5-8.1) subscales, and the International Knee Documentation Committee Subjective Knee Form (7.1-16.2). Other PROM thresholds differed up to 30 points. PASS thresholds converged to within a 10-point range in KOOS-ADL for ACL tears (92.3-100), and KOOS-Symptoms (73-78) and KOOS-QOL (53-57) in meniscus injuries. CONCLUSION: Meaningful PROM thresholds were highly susceptible to study heterogeneity. While PROM thresholds can aid interpretability in research and clinical practice, they should be cautiously interpreted.

How do Patient-reported Outcome Scores in International Hip and Knee Arthroplasty Registries Compare?

BACKGROUND: Patient-reported outcome measures (PROMs) are the only systematic approach through which the patient's perspective can be considered by surgeons (in determining a procedure's efficacy or appropriateness) or healthcare systems (in the context of value-based healthcare). PROMs in registries enable international comparison of patient-centered outcomes after total joint arthroplasty, but the extent to which those scores may vary between different registry populations has not been clearly defined. QUESTIONS/PURPOSES: (1) To what degree do mean change in general and joint-specific PROM scores vary across arthroplasty registries, and to what degree is the proportion of missing PROM scores in an individual registry associated with differences in the mean reported change scores? (2) Do PROM scores vary with patient BMI across registries? (3) Are comorbidity levels comparable across registries, and are they associated with differences in PROM scores? METHODS: Thirteen national, regional, or institutional registries from nine countries reported aggregate PROM scores for patients who had completed PROMs preoperatively and 6 and/or 12 months postoperatively. The requested aggregate PROM scores were the EuroQol-5 Dimension Questionnaire (EQ-5D) index values, on which score 1 reflects "full health" and 0 reflects "as bad as death." Joint-specific PROMs were the Oxford Knee Score (OKS) and the Oxford Hip Score (OHS), with total scores ranging from 0 to 48 (worst-best), and the Hip Disability and Osteoarthritis Outcome Score-Physical Function shortform (HOOS-PS) and the Knee Injury and Osteoarthritis Outcome Score-Physical Function shortform (KOOS-PS) values, scored 0 to 100 (worst-best). Eligible patients underwent primary unilateral THA or TKA for osteoarthritis between 2016 and 2019. Registries were asked to exclude patients with subsequent revisions within their PROM collection period. Raw aggregated PROM scores and scores adjusted for age, gender, and baseline values were inspected descriptively. Across all registries and PROMs, the reported percentage of missing PROM data varied from 9% (119 of 1354) to 97% (5305 of 5445). We therefore graphically explored whether PROM scores were associated with the level of data completeness. For each PROM cohort, chi-square tests were performed for BMI distributions across registries and 12 predefined PROM strata (men versus women; age 20 to 64 years, 65 to 74 years, and older than 75 years; and high or low preoperative PROM scores). Comorbidity distributions were evaluated descriptively by comparing proportions with American Society of Anesthesiologists (ASA) physical status classification of 3 or higher across registries for each PROM cohort. RESULTS: The mean improvement in EQ-5D index values (10 registries) ranged from 0.16 to 0.33 for hip registries and 0.12 to 0.25 for knee registries. The mean improvement in the OHS (seven registries) ranged from 18 to 24, and for the HOOS-PS (three registries) it ranged from 29 to 35. The mean improvement in the OKS (six registries) ranged from 15 to 20, and for the KOOS-PS (four registries) it ranged from 19 to 23. For all PROMs, variation was smaller when adjusting the scores for differences in age, gender, and baseline values. After we compared the registries, there did not seem to be any association between the level of missing PROM data and the mean change in PROM scores. The proportions of patients with BMI 30 kg/m 2 or higher ranged from 16% to 43% (11 hip registries) and from 35% to 62% (10 knee registries). Distributions of patients across six BMI categories differed across hip and knee registries. Further, for all PROMs, distributions also differed across 12 predefined PROM strata. For the EQ-5D, patients in the younger age groups (20 to 64 years and 65 to 74 years) had higher proportions of BMI measurements greater than 30 kg/m 2 than older patients, and patients with the lowest baseline scores had higher proportions of BMI measurements more than 30 kg/m 2 compared with patients with higher baseline scores. These associations were similar for the OHS and OKS cohorts. The proportions of patients with ASA Class at least 3 ranged across registries from 6% to 35% (eight hip registries) and from 9% to 42% (nine knee registries). CONCLUSION: Improvements in PROM scores varied among international registries, which may be partially explained by differences in age, gender, and preoperative scores. Higher BMI tended to be associated with lower preoperative PROM scores across registries. Large variation in BMI and comorbidity distributions across registries suggest that future international studies should consider the effect of adjusting for these factors. Although we were not able to evaluate its effect specifically, missing PROM data is a recurring challenge for registries. Demonstrating generalizability of results and evaluating the degree of response bias is crucial in using registry-based PROMs data to evaluate differences in outcome. Comparability between registries in terms of specific PROMs collection, postoperative timepoints, and demographic factors to enable confounder adjustment is necessary to use comparison between registries to inform and improve arthroplasty care internationally. LEVEL OF EVIDENCE: Level III, therapeutic study.

Estimation of Patient Acceptable Symptom State (PASS) and Treatment Failure (TF) Threshold Values for the Achilles Tendon Total Rupture Score (ATRS) at 6 Months, 1 Year, and 2 Years After Acute Achilles Tendon Rupture.

Interpretation of the Achilles tendon Total Rupture Score (ATRS) is challenging because limited knowledge exists about at which score the patients consider the outcome of treatment as satisfactory. The aims of the study were (1) to describe the proportion of patients who find their symptom levels to be satisfactory, to reflect treatment failure or neither after acute Achilles tendon rupture (ATR), and (2) to estimate the Patient Acceptable Symptom State (PASS) and the Treatment Failure (TF) threshold values for the ATRS at 6 months, 1 year, and 2 years after ATR. The study was based on data extracted from the nationwide Danish Achilles tendon Database which includes patients treated operatively or nonoperatively after ATR. The PASS and TF threshold values for ATRS were estimated using the adjusted predictive modeling method. One hundred and sixty-six patients were included at 6 months, 248 patients at 1 year, and 287 patients at 2 years after ATR. The proportion of patients who considered their symptom level to be satisfactory was 61% at 6 months, 50% at 1 year, and 66% at 2 years, while 5% at 6 months, 11% at 1 year, and 10% at 2 years considered their symptom level to reflect treatment failure. The PASS threshold value for ATRS (95% confidence interval) was 49 (46-52) at 6 months, 57 (54-60) at 1 year, and 52 (49-55) at 2 years. The TF threshold value for ATRS was 30 (23-36) at 6 months, 33 (26-40) at 1 year, and 35 (29-39) at 2 years. The calculated PASS and TF threshold values can help interpret the outcome of ATR when measured with the ATRS. About 50% to 66% of the patients had a satisfactory symptom level after ATR.

Disentangling treatment pathways for knee osteoarthritis: a study protocol for the TREATright study including a prospective cohort study, a qualitative study and a cost-effectiveness study.

INTRODUCTION: Knee osteoarthritis (OA) is associated with chronic knee pain and functional disability that negatively affect the ability to carry out normal daily activities. Patients are offered a large variety of non-surgical treatments, often not in accordance with clinical guidelines. This observational study will provide a comprehensive overview of treatment pathways for knee OA during the first 2 years after consulting an orthopaedic surgeon, including timing and order of treatment modalities, predictors of treatment outcomes, cost-effectiveness of treatment pathways and patients' views on different treatment pathways. METHODS AND ANALYSIS: Patients with primary referrals to an orthopaedic surgeon due to knee OA are consecutively invited to participate and fill out a questionnaire prior to their consultation with an orthopaedic surgeon. Follow-up questionnaires will be obtained at 6 and 24 months after inclusion. Based on a prospective cohort study design, including questionnaires and register data, we will (1) describe treatment pathways for knee OA during the first 2 years after consulting an orthopaedic surgeon; (2) describe the characteristics of patients choosing different treatment pathways; (3) develop predictive models for patient-self-determined classifications of good and poor treatment outcomes; (4) evaluate the cost-effectiveness of treatment pathways that live up to clinical guidelines versus pathways that do not; based on a qualitative study design using semistructured individual interviews, we will (5) describe the patients' perspectives on treatment pathways for knee OA. ETHICS AND DISSEMINATION: The study is approved by the Danish regional ethical committee (journal number H-17017295) and the Danish Data Protection Agency (journal number AHH-2017-072). Data will be anonymised and handled in line with the General Data Protection Regulation and the Danish Data Protection Act. The study results will be submitted to international open-access peer-reviewed journals and disseminated at conferences. TRIAL REGISTRATION NUMBER: NCT03746184, pre-results.

Collection and Reporting of Patient-reported Outcome Measures in Arthroplasty Registries: Multinational Survey and Recommendations.

BACKGROUND: Patient-reported outcome measures (PROMs) are validated questionnaires that are completed by patients. Arthroplasty registries vary in PROM collection and use. Current information about registry collection and use of PROMs is important to help improve methods of PROM data analysis, reporting, comparison, and use toward improving clinical practice. QUESTIONS/PURPOSES: To characterize PROM collection and use by registries, we asked: (1) What is the current practice of PROM collection by arthroplasty registries that are current or former members of the International Society of Arthroplasty Registries, and are there sufficient similarities in PROM collection between registries to enable useful international comparisons that could inform the improvement of arthroplasty care? (2) How do registries differ in PROM administration and demographic, clinical, and comorbidity index variables collected for case-mix adjustment in data analysis and reporting? (3) What quality assurance methods are used for PROMs, and how are PROM results reported and used by registries? (4) What recommendations to arthroplasty registries may improve PROM reporting and facilitate international comparisons? METHODS: An electronic survey was developed with questions about registry structure and collection, analysis, reporting, and use of PROM data and distributed to directors or senior administrators of 39 arthroplasty registries that were current or former members of the International Society of Arthroplasty Registries. In all, 64% (25 of 39) of registries responded and completed the survey. Missing responses from incomplete surveys were captured by contacting the registries, and up to three reminder emails were sent to nonresponding registries. Recommendations about PROM collection were drafted, revised, and approved by the International Society of Arthroplasty Registries PROMs Working Group members. RESULTS: Of the 25 registries that completed the survey, 15 collected generic PROMs, most frequently the EuroQol-5 Dimension survey; 16 collected joint-specific PROMs, most frequently the Knee Injury and Osteoarthritis Outcome Score and Hip Disability and Osteoarthritis Outcome Score; and 11 registries collected a satisfaction item. Most registries administered PROM questionnaires within 3 months before and 1 year after surgery. All 16 registries that collected PROM data collected patient age, sex or gender, BMI, indication for the primary arthroplasty, reason for revision arthroplasty, and a comorbidity index, most often the American Society of Anesthesiologists classification. All 16 registries performed regular auditing and reporting of data quality, and most registries reported PROM results to hospitals and linked PROM data to other data sets such as hospital, medication, billing, and emergency care databases. Recommendations for transparent reporting of PROMs were grouped into four categories: demographic and clinical, survey administration, data analysis, and results. CONCLUSION: Although registries differed in PROM collection and use, there were sufficient similarities that may enable useful data comparisons. The International Society of Arthroplasty Registries PROMs Working Group recommendations identify issues that may be important to most registries such as the need to make decisions about survey times and collection methods, as well as how to select generic and joint-specific surveys, handle missing data and attrition, report data, and ensure representativeness of the sample. CLINICAL RELEVANCE: By collecting PROMs, registries can provide patient-centered data to surgeons, hospitals, and national entities to improve arthroplasty care.

What is the effect of supervised rehabilitation regime vs. self-management instruction following unicompartmental knee arthroplasty? - a pilot study in two cohorts.

PURPOSE: The optimal rehabilitation strategy after a unicompartmental knee arthroplasty (UKA) is unclear. This study aims to compare the effect of transitioning from a supervised to a self-management rehabilitation regime by pilot study of patient outcomes subsequent to UKA surgery. METHODS: Fifty consecutive patients scheduled to undergo unilateral UKA surgery at our institution between 22nd February 2016 and 18thof January 2017 were prospectively identified via local medical database and included. Performed UKAs were grouped into two cohorts, Supervised Cohort and Self-management Cohort, temporally separated by introduction of new rehabilitation. Self-management Cohort(n = 25) received an extensive inpatient rehabilitation regime along with outpatient referral to rehabilitation center. The Self-management Cohort(n = 25) were only instructed in use of crutches and free ambulation at own accord. Follow-up (F/U) was 1 year from receiving UKA. A range of outcomes were recorded, and between-cohort differences compared: knee joint range of motion, pain and functional limitations, length of stay (LOS), readmission rate, pain during activity and rest, and knee circumference. RESULTS: Complete data was obtained for n = 45 patients. The mean between-cohort difference in ROM (range of motion) from preoperatively to discharge was 15.4 degrees (CI:5.2,25.8, p = 0.004), favoring the supervised regime, with no difference detected in any outcome at 3- or 12 months F/U. Median LOS was 1 day in both cohorts. CONCLUSION: Transition to a simple rehabilitation regime following UKA surgery was associated with decreased ROM at discharge, which was not present at 3-month F/U. We found no other between-cohort differences for any other outcomes at 3- and 12-month F/U including functional limitations, although the study was likely underpowered for these outcomes. We encourage large-scale replication of these findings using randomized designs. LEVEL OF EVIDENCE: Therapeutic level II.

Cutoff Values to Interpret Short-term Treatment Outcomes After Arthroscopic Meniscal Surgery, Measured With the Knee Injury and Osteoarthritis Outcome Score.

OBJECTIVE: To determine the proportions of patients who (1) perceived their symptoms to be satisfactory, (2) perceived their treatment to have failed, or (3) perceived that they improved to an important degree at 3 months after arthroscopic meniscal surgery; and to determine Knee injury and Osteoarthritis Outcome Score (KOOS) subscale scores corresponding to the Patient Acceptable Symptom State (PASS), treatment failure, and the minimal important change (MIC) for improvement. DESIGN: Prospective cohort study. METHODS: Patients from the Knee Arthroscopy Cohort Southern Denmark who had arthroscopic meniscal surgery were included. The PASS, treatment failure, and MIC improvement values were calculated for the KOOS subscales with anchor-based approaches, using the adjusted predictive modeling method. Subgroup analyses were performed by stratifying by age (40 years or younger versus older than 40 years) and surgery type. RESULTS: Six hundred fourteen patients (44% female; mean ± SD age, 50 ± 13 years) were included. At 3 months after arthroscopic meniscal surgery, 45% of patients perceived their symptoms to be satisfactory, 19% perceived the treatment to have failed, and 44% to 60% perceived that they had improved to an important degree across the 5 KOOS subscales (for PASS/treatment failure, respectively: pain, 74 and 60 points; symptoms, 72 and 61 points; function in activities of daily living, 81 and 68 points; sport and recreational function, 43 and 26 points; and knee-related quality of life, 52 and 40 points; for MIC improvement: pain, 12 points; symptoms, 8 points; function in activities of daily living, 12 points; sport and recreational function, 17 points; and knee-related quality of life, 9 points). The PASS values were 6 to 17 points higher for patients 40 years or younger compared to patients older than 40 years. CONCLUSION: At 3 months after meniscal surgery, approximately half of the patients perceived their symptoms to have improved to an important degree, 4 in every 10 patients perceived their symptoms to be satisfactory, and 2 in every 10 patients perceived the treatment to have failed. J Orthop Sports Phys Ther 2021;51(6):281-288. Epub 30 Jan 2021. doi:10.2519/jospt.2021.10149.

Establishing research priorities related to osteoarthritis care via stakeholder input from patients.

INTRODUCTION: Stakeholder involvement in research is emphasised to improve relevance. We aimed to identify, define and prioritise important research topics seen from the point of view of people with osteoarthritis (OA). METHODS: We invited 1,315 members of the user panel of the Danish Rheumatism Association to answer an electronic survey that included; 1) an open-ended question about important research topics (free-text response option), 2) 15 predefined research topics to be rated for importance and 3) predefined topics grouped into four categories in which the most important was prioritised. Free-text responses were analysed using content analysis. RESULTS: Out of 850 (65%) respondents, 483 had OA (mean ± standard deviation age 60.3 ± 10.2 years, 91% female). From the free-text responses, we identified seven research topics; 1) diagnostics, 2) prevention, 3) side effects, 4) treatment, 5) aetiology, 6) being young with OA and 7) quality of life. For "treatment", we identified seven subtopics. Out of all topics and subtopics, "pain management" was the most frequently highlighted. All predefined topics were rated as "very important" or "somewhat important" by more than 75% of the respondents. The top prioritised topics within each category were 1) improving the diagnosis, 2) individualised treatment, 3) shared decision-making and 4) cross-sector collaboration and collaboration between professionals. CONCLUSIONS: We identified research topics that were important in the eyes of people with OA and found that "pain management" was particularly emphasised. FUNDING: none. TRIAL REGISTRATION: not relevant.

Are functional outcomes and early pain affected by discharge on the day of surgery following total hip and knee arthroplasty?

Background and purpose - Outpatient total knee and total hip arthroplasty (TKA and THA) has been shown to be feasible and safe in selected patients. However, little data is available on functional outcome and early pain in patients discharged on the day of surgery (DOS). We investigated patient-reported outcomes at 1 year and early pain in outpatient TKA and THA patients discharged on the day of surgery (DOS) (DDOS) compared with patients scheduled for outpatient surgery but not discharged on the DOS (nDDOS).Patients and methods - Prospective data on 261 consecutive patients scheduled for outpatient TKA (n = 126) and THA (n = 135) were collected. 37% of TKA patients and 33% of THA patients were discharged on the DOS. Pain scores at rest and activity and use of morphine were registered on postoperative days 1-7. Oxford Knee Score (OKS) and Oxford Hip Score (OHS) were collected preoperatively and at 3 and 12 months' follow-up.Results - DDOS and nDDOS patients were similar in respect to age, sex, procedure type (TKA vs. THA), or preoperative OKS or OHS. Neither OKS nor OHS differed between groups at 3 and 12 months' follow-up. Pain at rest and activity and use of morphine did not differ between the 2 groups on days 1-7.Interpretation - In patients scheduled for outpatient TKA and THA, we found similar patient-reported outcomes both early and at 1 year in those discharged on the DOS and those who had at least 1 overnight stay.

Categorization of changes in the Oxford Knee Score after total knee replacement: an interpretive tool developed from a data set of 46,094 replacements.

OBJECTIVES: The objective of the study was to create an interpretive categorical classification for the transition in the Oxford Knee Score (OKS) change score (ΔOKS) using the anchor-based method. STUDY DESIGN AND SETTING: Registry data from 46,094 total knee replacements from the year 2014/15, were accessed via the Health and Social Care Information Center official website. Data included preoperative and 6-month follow-up OKS and response to the transition anchor question. Categories were determined using Gaussian approximation probability and k-fold cross-validation. RESULTS: Four categories were identified with the corresponding ΔOKS intervals: "1. much better" (≥16), "2. a little better" (7-15), "3. about the same" (1-6), and "4. much worse" (≤0) based on the anchor questions' original five categories. The mean 10-fold cross-validation error was 0.35 OKS points (95% confidence interval 0.12 to 0.63). Sensitivity ranged from 0.34 to 0.68; specificity ranged from 0.74 to 0.95. CONCLUSION: We have categorized the change score into a clinically meaningful classification. We argue it should be an addition to the continuous OKS outcome to contextualize the results in a way more applicable to the shared decision-making process and for interpreting research results.

Unlike ROC analysis, a new IRT method identified clinical thresholds unbiased by disease prevalence.

OBJECTIVE: This study introduces a new method to establish clinical thresholds for multi-item tests, based on item response theory (IRT), as an alternative to receiver operating characteristic (ROC) analysis. The performance of IRT method was examined and compared with the ROC method across multiple simulated data sets and in a real data set. STUDY DESIGN AND SETTING: Simulated data sets (sample size: 1,000) varied in means and variability of the test scores and the prevalence of disease. The true clinical threshold was defined as a predetermined location on the latent trait underlying the questionnaire, with its corresponding expected test score. The real data set (sample size: 295) comprised Hospital Anxiety Depression Scale (HADS) depression scores and Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition major depressive disorder (MDD) diagnoses. RESULTS: The IRT method recovered the clinical thresholds without bias, whereas the ROC method identified thresholds that were biased by the prevalence of disease. Mild MDD was clinically diagnosed in 23%, moderate MDD in 12%, and severe MDD in 14% of the participants. The IRT method identified the following HADS depression score thresholds for mild, moderate, and severe MDD: 10.7, 13.2, and 15.1, respectively. CONCLUSION: The new IRT method identifies clinical thresholds that are unbiased by disease prevalence.

Patient-acceptable symptom state for the Oxford Hip Score and Forgotten Joint Score at 3 months, 1 year, and 2 years following total hip arthroplasty: a registry-based study of 597 cases.

Background and purpose - Patient-acceptable symptom states (PASS) represent the level on a patient-reported outcome measure (PROM) at which patients are satisfied with postoperative outcomes. We defined the PASS for the Oxford Hip Score (OHS) and Forgotten Joint Score (FJS-12) at 3-month, 1-year, and 2-year intervals after primary total hip arthroplasty (THA).Patients and methods - Between July 2018 and April 2019, primary THA patients in an academic medical center's registry completed the OHS, FJS-12, and a satisfaction anchor question at 3-month (n = 230), 1-year (n = 180), or 2-year (n = 187) postoperative intervals. PASS thresholds were derived with receiver operating characteristic analysis using the 80% specificity method. 95% confidence intervals (CI) were calculated using 1,000 non-parametric bootstrap replications.Results - 74%, 85%, and 86% of patients reported having a satisfactory symptom state at 3 months, 1, and 2 years after surgery, respectively. At 3-month, 1-year, and 2-year intervals, PASS thresholds were 34 (CI 31-36), 40 (CI 36-44), and 39 (CI 35-42) points for the OHS and 59 (CI 54-64), 68 (CI 61-75), and 69 (CI 62-75) points for the FJS-12.Interpretation - PASS thresholds varied with time for both the OHS and the FJS-12, with lower 3-month compared with 1-year and 2-year thresholds. These PASS thresholds represent OHS and FJS-12 levels at which the average patient is satisfied with THA outcomes, helping to interpret PROMs and serving as clinically significant benchmarks and patient-centered outcomes for research.

Are There Differences in Micromotion on Radiostereometric Analysis Between Bicruciate and Cruciate-retaining Designs in TKA? A Randomized Controlled Trial.

BACKGROUND: Bicruciate-retaining TKA has been proposed to improve clinical outcomes by maintaining intrinsic ACL function. However, because the unique design of the bicruciate-retaining tibial component precludes a tibial stem, fixation may be compromised. A radiostereometric analysis permits an evaluation of early migration of tibial components in this setting, but to our knowledge, no such analysis has been performed. QUESTIONS/PURPOSES: We performed a randomized controlled trial using a radiostereometric analysis and asked, at 2 years: (1) Is there a difference in tibial implant migration between the bicruciate-retaining and cruciate-retaining TKA designs? In a secondary analysis, we asked: (2) Is there a difference in patient-reported outcomes (Oxford Knee Score [OKS] and Forgotten Joint Score [FJS] between the bicruciate-retaining and cruciate-retaining TKA designs? (3) What is the frequency of reoperations and revisions for the bicruciate-retaining and cruciate-retaining TKA designs? METHODS: This parallel-group trial (ClinicalTrials.gov: NCT01966848) randomized 50 patients with an intact ACL who were eligible to undergo TKA to receive either a bicruciate-retaining or cruciate-retaining TKA. Patients were blinded to treatment allocation. The primary outcome was the maximum total point motion (MTPM) of the tibial component measured with model-based radiostereometric analysis (RSA) at 2 years postoperatively. The MTPM is a translation vector defined as the point in the RSA model that has the greatest combined translation in x-, y- and z-directions. A 1-year postoperative mean MTPM value of 1.6 mm has been suggested as a threshold for unacceptable increased risk of aseptic loosening after both 5 and 10 years. The repeatability of the MTPM was found to be 0.26 mm in our study. Patient-reported outcome measures were assessed preoperatively and at 2 years postoperatively with the OKS (scale of 0-48, worst-best) and FJS (scale of 0-100, worst-best). Baseline characteristics did not differ between groups. At 2 years postoperatively, RSA images were available for 22 patients who underwent bicruciate-retaining and 23 patients who underwent cruciate-retaining TKA, while patient-reported outcome measures were available for 24 patients in each group. The study was powered to detect a 0.2-mm difference in MTPM between groups (SD = 0.2, significance level = 5%, power = 80%). RESULTS: With the numbers available, we found no difference in MTPM between the bicruciate-retaining and cruciate-retaining groups. The median (interquartile range [IQR]) MTPM was 0.52 mm (0.35 to 1.02) and 0.42 mm (0.34 to 0.70) in the bicruciate-retaining and cruciate-retaining groups, respectively (p = 0.63). There was no difference in the magnitude of improvement in the OKS from preoperatively to 2 years postoperative between the groups (median delta [IQR] for bicruciate-retaining 18 [14 to 23] versus cruciate-retaining 18 [15 to 21], difference of medians 0; p = 0.96). Likewise, there was no difference in the magnitude of improvement in the FJS score from preoperatively to 2 years postoperative between the groups (mean ± SD for bicruciate-retaining 46 ± 32 versus cruciate-retaining 48 ± 16, mean difference, 2; p = 0.80). Three patients in the bicruciate-retaining group underwent arthroscopically assisted manipulation at 3 to 4 months postoperatively, and one patient in the bicruciate-retaining group sustained a tibial island fracture during primary surgery and underwent a revision procedure after 6 months. There were no reoperations or revisions in the cruciate-retaining group. CONCLUSIONS: With the numbers available, we found no differences between the bicruciate-retaining and the cruciate-retaining implants in terms of stable fixation on RSA or patient-reported outcome measure scores at 2 years, and must therefore recommend against the routine clinical use of the bicruciate-retaining device. The complications we observed with the bicruciate-retaining device suggest it has an associated learning curve and the associated risks of novelty with no demonstrable benefit to the patient; it is also likely to be more expensive in most centers. Continued research on this implant should only be performed in the context of controlled trials. LEVEL OF EVIDENCE: Level II, therapeutic study.

It is good to feel better, but better to feel good: whether a patient finds treatment 'successful' or not depends on the questions researchers ask.

INTRODUCTION: In sports physiotherapy, medicine and orthopaedic randomised controlled trials (RCT), the investigators (and readers) focus on the difference between groups in change scores from baseline to follow-up. Mean score changes are difficult to interpret ('is an improvement of 20 units good?'), and follow-up scores may be more meaningful. We investigated how applying three different responder criteria to change and follow-up scores would affect the 'outcome' of RCTs. Responder criteria refers to participants' perceptions of how the intervention affected them. METHODS: We applied three different criteria-minimal important change (MIC), patient acceptable symptom state (PASS) and treatment failure (TF)-to the aggregate Knee injury and Osteoarthritis Outcome Score (KOOS4) and the five KOOS subscales, the primary and secondary outcomes of the KANON trial (ISRCTN84752559). This trial included young active adults with an acute ACL injury and compared two treatment strategies: exercise therapy plus early reconstructive surgery, and exercise therapy plus delayed reconstructive surgery, if needed. RESULTS: MIC: At 2 years, more than 90% in the two treatment arms reported themselves to be minimally but importantly improved for the primary outcome KOOS4. PASS: About 50% of participants in both treatment arms reported their KOOS4 follow-up scores to be satisfactory. TF: Almost 10% of participants in both treatment arms found their outcomes so unsatisfactory that they thought their treatment had failed. There were no statistically significant or meaningful differences between treatment arms using these criteria. CONCLUSION: We applied change criteria as well as cross-sectional follow-up criteria to interpret trial outcomes with more clinical focus. We suggest researchers apply MIC, PASS and TF thresholds to enhance interpretation of KOOS and other patient-reported scores. The findings from this study can improve shared decision-making processes for people with an acute ACL injury.

Meaningful Change Scores in the Knee Injury and Osteoarthritis Outcome Score in Patients Undergoing Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Meaningful change scores in the Knee injury and Osteoarthritis Outcome Score (KOOS) in patients undergoing anterior cruciate ligament (ACL) reconstruction have not yet been established. PURPOSE: To define the minimal important change (MIC) for the KOOS after ACL reconstruction. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: KOOS and anchor questions with 7-point scales ranging from "better, an important improvement" to "worse, an important worsening" were completed postoperatively by randomly chosen participants from the Norwegian Knee Ligament Registry. Presurgery KOOS scores were retrieved from the registry. The MIC for improvement was calculated with anchor-based approaches using the predictive modeling method adjusted for the proportion of improved patients, the mean change method, and the receiver operating characteristic (ROC) method. RESULTS: Complete data for at least one of the KOOS subscales were obtained from 542 (45.3%) participants. Predictive modeling MIC values were 12.1 for the KOOS subscales of Sport and Recreational Function and 18.3 for Knee-Related Quality of Life. These values aid in interpreting within-group improvement over time and can be used as responder criteria when comparing groups. The corresponding and much lower values for the subscales of Pain (2.5), Symptoms (-1.2), and Activities of Daily Living (2.4) are the results from patients reporting, on average, only mild problems with these domains preoperatively. Although 4% to 10% of patients reported subscale-specific worsening, MIC deterioration calculations were not possible. The ROC MIC values were associated with high degrees of misclassification. Values obtained by the mean change method were considered less reliable because these estimates are derived from subgroups of patients. Average KOOS change scores were approximately similar for patients reporting acceptable symptoms postoperatively and patients reporting important improvements on the anchor items after surgery. CONCLUSION: KOOS users should apply subscale-specific cutoffs for meaningful improvement. Our results confirm using the subscales of Sport and Recreational Function and Knee-Related Quality of Life as primary patient-reported outcomes after ACL reconstruction. The predictive modeling approach gave the most robust estimates of MIC values. Our data suggest that reporting acceptable symptoms postoperatively corresponds to reporting an important improvement after ACL reconstruction.