The assessment of outcome after total knee arthroplasty: are we there yet?

Predicting Outcome of Total Knee Arthroplasty by Cluster Analysis of Patient-Reported Outcome Measures

BACKGROUND

Total knee arthroplasties (TKAs) exhibit an 8 to 30% risk of suboptimal outcomes, resulting in persistent symptoms, individual morbidity, and revision surgery, prompting a contemporary focus on risk reduction and outcome improvement. This study introduces hierarchical cluster analysis as a way of preoperatively assessing the likelihood of success/failure of TKA based on several patient-reported outcome measures (PROMs), which have been analyzed both intact and with component questions as individual variables.

METHODS

The study utilized data on 1,433 TKAs from The Miriam Hospital's Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement registry. Outcomes are expressed as Knee Injury and Osteoarthritis Outcome Score pain and function scores. Criteria for success/failure were developed with an integrative, anchor-based, minimum clinically important difference. Preoperative and postoperative PROMs were studied by cluster analysis.

RESULTS

There were three sequential cluster analyses that revealed clusters of patients, based upon preoperative patient responses that were predictive of surgical outcomes. Clusters varied most significantly in their responses to individual component questions of preoperative PROMs. Extracting and combining the clinically meaningful patient-reported component questions yielded a new, and clinically relevant, outcome measure that has the potential to preoperatively predict postoperative outcomes of TKA.

CONCLUSIONS

In contrast to a single medical, psychological, or social variable, cluster analysis offers the opportunity to develop a whole-patient profile that reflects the contextual interactions of sociodemographic and clinical variables in predicting outcomes. In the context of determining clinical meaningfulness, cluster analysis has one of its major strengths.

Tibial Baseplate Migration Is Not Associated with Change in Patient-Reported Outcome Measures and Clinical Scores After TKA: A Secondary Analysis of 5 Radiostereometric Analysis Studies with 10-Year Follow-up

BACKGROUND

Radiostereometric analysis (RSA) provides highly accurate data about the migration of a total knee arthroplasty (TKA) component. However, patient-reported outcome measures (PROMs) reflect the patients' perspective of their functional status, pain, and overall health after TKA. The aim of this study was to evaluate the association between tibial implant migration and change in postoperative PROMs and clinical scores, using data pooled from long-term follow-up RSA studies.

METHODS

Individual implant migration data were collected from 5 randomized RSA studies, including a total of 300 patients with 6 distinct TKA implant designs (all Stryker). Tibial implant migration (maximum total point motion [MTPM]) was evaluated with RSA at 3 months, 1 year, and 2, 5, 7, and 10 years postoperatively. The Knee Society Score (KSS)-Knee and KSS-Function and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were collected in all studies at the same follow-up times. Linear mixed-effects models, with adjustment for TKA implant design and patient characteristics, were used to analyze the data. The 3-month follow-up visit was used as the baseline to assess the association between implant migration and PROMs across the 10-year follow-up.

RESULTS

No association between tibial implant migration and change in KSS-Knee (p = 0.384), KSS-Function (p = 0.737), KOOS-Symptoms (p = 0.398), KOOS-Pain (p = 0.699), KOOS-Activities of Daily Living (p = 0.205), KOOS-Sport and Recreation (p = 0.702), or KOOS-Quality of Life (p = 0.368) was found across the entire follow-up. Similar results were found when using the 2-year follow-up as the baseline, after which both cemented and uncemented implants are expected to have stabilized.

CONCLUSIONS

Tibial baseplate migration was not associated with postoperative worsening in PROMs or clinical scores in patients who underwent TKA. These findings suggest that implant migration, as measured with RSA, measures a different parameter (i.e., implant-bone fixation) than PROMs (i.e., patient perception) and clinical scores. Therefore, to assess the performance and safety of TKA implant designs, RSA and PROMs cannot be used interchangeably during the postoperative follow-up of patients and evaluation of the fixation of knee implants.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Early and delayed periprosthetic joint infection in robot-assisted total knee arthroplasty: a multicenter study

BACKGROUND

Robot-assisted total knee arthroplasty (RA-TKA) has significantly improved knee surgery outcomes in the last few years. However, its association with the periprosthetic joint infection (PJI) rate remains debatable. This study investigates the incidence of early and delayed PJI in a multicentric cohort of patients who underwent RA-TKA, aiming to elucidate the risk associated with this procedure.

METHODS

This retrospective study analyzed data from a consecutive series of patients who underwent RA-TKA using the NAVIO Surgical System (Smith & Nephew, Memphis, USA) between 2020 and 2023. The inclusion criteria encompassed individuals over 18 years of age with a minimum follow-up period of three months. The primary outcome was the incidence of early and delayed PJI, defined according to the European Bone and Joint Infection Society (EBJIS) diagnostic criteria. Secondary outcomes included the evaluation of postoperative complications.

RESULTS

The study included patients who underwent RA-TKA with the NAVIO system, achieving an average follow-up of 9.1 ± 3.9 months. None of the patients met the EBJIS criteria for a likely or confirmed infection, indicating an absence of both early and delayed PJI cases. Two patients required subsequent surgical interventions due to patellar maltracking and prosthetic loosening, respectively. Additionally, three patients underwent passive manipulation under anesthesia (MUA).

CONCLUSION

The findings indicate no evidence of early or delayed PJI in patients undergoing RA-TKA within the study period. The low complication rate further supports the reliability and safety of this surgical technique in short-term follow-up.

LEVEL OF EVIDENCE

IV.

Reliability, Concurrent Validity, and Minimal Detectable Change of the Hand-Held Dynamometry for the Assessment of Knee Muscle Strength in Patients With Revision Total Knee Arthroplasty

OBJECTIVE

To determine the concurrent validity, reliability, and minimal detectable change (MDC) of the hand-held dynamometry (HHD) for knee strength measurement in patients with revision total knee arthroplasty (r-TKA).

DESIGN

A reliability and validity analysis.

SETTING

Orthopedic and physical therapy services of university hospital.

PARTICIPANTS

The study included 42 patients with r-TKA (N=42).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Knee muscle strength assessments were performed by 2 physiotherapists in 3 different sessions by using HHD. Participants were instructed to exert a maximal force for lasting 5 seconds against HHD. The first examiner performed the strength testing, and after 30-minutes rest, the second examiner performed the same procedure for inter-examiner reliability. One hour after the initial testing, the first examiner reperformed the strength testing for intra-examiner reliability. The correlations of the knee extensors and knee flexors strength with 50-foot walking test and 30-second chair stand test were assessed for concurrent validity.

RESULTS

The inter-examiner reliabilities of knee extensors and flexors strength measurements were 0.97 and 0.95, respectively. The SEM and the minimal detectable changes at 95% confidence level (MDC95) for knee extensors were 10.39 and 28.65 Newton-meters (Nm), and SEM and MDC95 for knee flexors were 8.70 and 23.99 Nm, respectively. The intra-examiner reliabilities of knee extensors and flexors strength measurements were 0.96. SEM and MDC95 for knee extensors were 12.00 and 33.09 Nm, and SEM and MDC95 for knee flexors were 7.78 and 21.45 Nm, respectively. The knee muscle strength showed strong significant correlations with physical performance tests (all, P<.05).

CONCLUSIONS

The HHD is a reliable and valid method for assessment of static knee strength after r-TKA. The HHD can be used to quantify changes in knee strength and also assists the clinicians to determine the effect of rehabilitation programs on muscle strength following r-TKA surgery.

Differences in Outcomes Between Initial Responders and Subsequent Responders to Health Questionnaires for Total Hip and Knee Arthroplasty: An Australian Tertiary Institutional Registry Study

BACKGROUND

Patient-reported outcome measure (PROM) questionnaires in national arthroplasty registries often have low response rates leading to questions about data reliability. In Australia, the SMART (St. Vincent's Melbourne Arthroplasty Outcomes) registry captures all elective total hip (THA) and total knee (TKA) arthroplasty patients with an approximate 98% response rate for preoperative and 12-month PROM scores. This high response rate is due to dedicated registry staff following up patients who do not initially respond (subsequent responders). This study compared initial responders to subsequent responders to find differences in 12-month PROM outcomes for THA and TKA.

METHODS

All elective THA and TKA patients for osteoarthritis from 2012 to 2021 captured by the SMART registry were included. In total, 1,333 THA and 1,340 TKA patients were included. The PROM scores were assessed using the Veterans-RAND 12 (VR12) and Western Ontario and McMasters Universities Arthritis Index (WOMAC) questionnaires. The primary outcome was differences in mean 12-month PROM scores between initial and subsequent responders.

RESULTS

Baseline characteristics and PROM scores were similar between initial and subsequent responders. However, 12-month PROM scores varied significantly. The adjusted mean difference showed that for the WOMAC pain score, subsequent responders scored 3.4 points higher in the THA cohort and 7.4 points higher in the TKA cohort compared to initial responders. Significant differences were also found in other WOMAC and VR12 scores for both THA and TKA cohorts at the 12-month timepoint.

CONCLUSION

This study found that significant differences in PROM outcomes postsurgery occurred in THA and TKA patients based on response to PROM questionnaires, suggesting that loss to follow-up in PROM outcomes should not be treated as missing completely at random (MCAR).

Patient-Reported Outcome Measures: State of the Art in Patient-Reported Outcome Measure Application in Lower Extremity Orthopaedics

With an increasing shift toward a value-based and outcome-driven healthcare system, patient-reported outcome measures (PROMs) will continue to play a prominent role in assessing performance, making clinical decisions, shared decision making, and determining the comparative effectiveness of procedures such as total joint arthroplasty for lower extremity conditions, such as ankle, hip, and knee osteoarthritis. As the application of PROMs in evaluating surgical outcomes has evolved from that of a research setting to that of a clinical setting, their use in the decision-making process has become more prevalent. As a result, preoperative optimization, surgical indications, and improved outcomes after surgery have been greatly enhanced. To enable benchmarking, quality reporting, and performance measurement at an aggregate level, it is crucial to have a comprehensive PROM collection system. However, achieving this goal is contingent upon addressing the variability in reported PROMs and the patient-centered benchmarks used to analyze clinical significance.

Health-related quality of life among patients with knee osteoarthritis in Guangzhou, China: a multicenter cross-sectional study

PURPOSES

To investigate health-related quality of life (HRQoL) of patients with knee osteoarthritis (KOA) in Guangzhou, China, and examine its association with selected sociodemographic characteristics as well as knee function.

METHODS

This multicenter cross-sectional study included 519 patients with KOA in Guangzhou from April 1 to December 30, 2019. Data on sociodemographic characteristics were obtained using the General Information Questionnaire. The disability was measured using the KOOS-PS, resting pain using the Pain-VAS, and HRQoL using the EQ-5D-5L. The association of selected sociodemographic factors, KOOS-PS and Pain-VAS scores with HRQoL (EQ-5D-5L utility and EQ-VAS scores) were analyzed using linear regression analyses.

RESULTS

The median (interquartile range [IQR]) of EQ-5D-5L utility and EQ-VAS scores were 0.744 (0.571-0.841) and 70 (60-80) respectively, lower than the average HRQoL in the general population. Only 3.661% of KOA patients reported no problems in all EQ-5D-5L dimensions, with Pain/Discomfort being the most frequently affected dimension (78.805%). The correlation analysis showed that the KOOS-PS score, Pain-VAS score and HRQoL were moderately or strongly correlated. Patients with cardiovascular disease, no daily exercise, and high KOOS-PS or Pain-VAS scores had lower EQ-5D-5L utility scores; and patients with body mass index (BMI) > 28 ,high KOOS-PS or Pain-VAS scores had lower EQ-VAS scores.

CONCLUSIONS

Patients with KOA had relatively low HRQoL. Various sociodemographic characteristics as well as knee function were associated with HRQoL in regression analyses. Providing social support and improving their knee function through methods such as total knee arthroplasty might be crucial to improve their HRQoL.

The utility of machine learning algorithms for the prediction of patient-reported outcome measures following primary hip and knee total joint arthroplasty

BACKGROUND

Patient-reported outcome measures (PROMs) are increasingly used as quality benchmark in total hip and knee arthroplasty (THA; TKA) due to bundled payment systems that aim to provide a patient-centered, value-based treatment approach. However, there is a paucity of predictive tools for postoperative PROMs. Therefore, this study aimed to develop and validate machine learning models for the prediction of numerous patient-reported outcome measures following primary hip and knee total joint arthroplasty.

METHODS

A total of 4526 consecutive patients (2137 THA; 2389 TKA) who underwent primary hip and knee total joint arthroplasty and completed both pre- and postoperative PROM scores was evaluated in this study. The following PROM scores were included for analysis: HOOS-PS, KOOS-PS, Physical Function SF10A, PROMIS SF Physical and PROMIS SF Mental. Patient charts were manually reviewed to identify patient demographics and surgical variables associated with postoperative PROM scores. Four machine learning algorithms were developed to predict postoperative PROMs following hip and knee total joint arthroplasty. Model assessment was performed through discrimination, calibration and decision curve analysis.

RESULTS

The factors most significantly associated with the prediction of postoperative PROMs include preoperative PROM scores, Charlson Comorbidity Index, American Society of Anaesthesiology score, insurance status, age, length of hospital stay, body mass index and ethnicity. The four machine learning models all achieved excellent performance across discrimination (AUC > 0.83), calibration and decision curve analysis.

CONCLUSION

This study developed machine learning models for the prediction of patient-reported outcome measures at 1-year following primary hip and knee total joint arthroplasty. The study findings show excellent performance on discrimination, calibration and decision curve analysis for all four machine learning models, highlighting the potential of these models in clinical practice to inform patients prior to surgery regarding their expectations of postoperative functional outcomes following primary hip and knee total joint arthroplasty.

LEVEL OF EVIDENCE

Level III, case control retrospective analysis.

Higher Dissatisfaction Rate Following Revision Compared With Primary Total Knee Arthroplasty: 1-Year Follow-up of 2151 Primary and 235 Aseptic Revision Surgeries

Postoperative patient satisfaction is related to preoperative expectations. Information regarding expected results following surgery is therefore important. This study evaluated patient-reported outcome measures (PROMs) and patient satisfaction up to 1 year after primary and aseptic revision total knee arthroplasty (TKA). The study included 2151 primary and 235 aseptic revision TKA surgeries conducted between 2010 and 2018. Pain, Knee Injury and Osteoarthritis Outcome Score-Physical Function-Short Form and European Quality of Life-5 Dimension surveys were recorded preoperatively and at 8 weeks and 1 year. To determine satisfaction, patients were asked to rate their knee function compared with that before surgery and to answer whether they would undergo the surgery again given their current knowledge. Patients who had primary TKA improved in all PROMs in each follow-up up to 1 year, whereas patients who had revision TKA showed improvement at 8 weeks with no further improvement at 1 year. In terms of patient satisfaction, 88% of patients in the primary TKA group reported better knee function, and 87% were willing to have the surgery again at 1 year; the proportions were lower for patients who underwent revision TKA (66% and 68%, respectively). Aseptic revision TKA demonstrates inferior PROMs compared with those of primary TKA 1 year after surgery, and more than 30% of the patients who underwent revision TKA stated that they would not have their TKA revised or were uncertain, given the outcome of the procedure. Thus, patients who are candidates for revision TKA should be informed to expect less of an improvement following revision surgery than with the primary TKA. Our findings can facilitate the shared decision-making process by surgeons and patients based on realistic expectations of surgical outcomes. [Orthopedics. 2023;46(1):e52-e57.].

Time for return to sport following total knee arthroplasty: a meta-analysis

INTRODUCTION

The frequency of total knee arthroplasty (TKA) is increasing, particularly in younger and more active patients. In these patients, there may be greater functional demands, with an expectation to return to sporting activities (RTS) following TKA. There is a paucity of data on the time to RTS following TKA and the aim of this meta-analysis is to determine the time to RTS following TKA.

METHODS

Using the PRISMA guidelines, an electronic search of PUBMED, MEDLINE, EMBASE, and the Cochrane Library for trails was performed on TKA and RTS in English language, published since the inception of the database to 31st October 2020. Data evaluating the time to RTS and functional outcomes were recorded by two authors independently that were included in the analysis. Pooled analysis using random effect model on overall proportions at the different time intervals and at the end of the follow-up was carried out for all studies.

RESULTS

In total, 1,611 studies were retrieved from literature search. Of these, nine studies met the inclusion criteria with 1,307 patients. Two studies with 148 patients demonstrated an overall pooled proportion of 18.7% (95% CI 8.2-32.3%) of patients RTS at 3 month post-TKA; Three studies reported RTS rate at 6 months 70.% (95% CI 48-88.4). Two studies with 123 patients demonstrated an overall pooled proportion of 84.0% (95% CI 77.1-89.9%) patients RTS at 12 months. 986 patients returned to sport from total of 1307, with an overall adjusted proportion return to sport of 87.9 (95% CI 80.5-93.8%) at the end of follow-up; mean 14 months (range 3-36 months).

CONCLUSION

Patients undergoing TKA were found to successfully RTS, pooled proportion analysis showed an increasing rate of RTS with time, at a mean of 14 months following TKA, where 87.9% of patients had returned to sports. The findings of this study will enable more informed discussions and rehabilitation planning between patients and clinicians on RTS following TKA.

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

Background

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

Methods

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

Results

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

Conclusion

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

A single type of varus knee does not exist: morphotyping and gap analysis in varus OA

PURPOSE

To achieve a higher level of satisfaction in patients having undergone Total Knee Arthroplasty (TKA), a more personalized approach has been discussed recently. It can be assumed that a more profound knowledge of bony morphology and ligamentous situation would be beneficial. While CT/MRI can give 3D information on bone morphology, the understanding of the ligamentous situation in different flexion angles is still incomplete. In this study, the dynamic gap widths of a large number of varus knees were assessed in various flexion angles, to find out whether all varus knees behave similar or have more individual soft tissue patterns. Additionally, it was investigated whether the amount of varus deformity or other patient factors have an effect on joint gap widths.

METHODS

A series of 1000 consecutive TKA patients, including their CAS data and patient records were analyzed. Joint gap widths in multiple flexion angles (0°, 30°, 60°, 90°) were measured in mm and differences between the joint gaps were compared. A "standard" varus knee was defined as follows: (1) Lateral extension gap greater than medial, (2) lateral flexion gap greater than medial, and (3) flexion gap greater than extension gap. The percentage of fulfillment was tested for each and all criteria. To measure the influence of varus deformity on gap width difference, three subgroups were formed based on the deformity. Data were analyzed at 0°, 30°, 60° and 90° flexion. The effect of patient factors (gender, BMI, age) on gap sizes was tested by performing subgroup analyses.

RESULTS

Only 444 of 680 (65%) patients met all three varus knee criteria. The lateral extension gap (4.1 mm) was significantly larger than the medial extension gap (0.6 mm) in 657 (97%) patients and the gap difference highly correlated with the amount of varus deformity (r² = 0.62). In all flexion positions, however, no correlation between gap differences and varus deformity existed. Women had significantly larger extension and flexion gaps. Age and BMI showed no significant effect on gap widths.

CONCLUSION

Varus knees show a large inter-individual variability regarding gap widths and gap differences. The amount of varus deformity correlates highly with the medio-lateral gap difference in extension, but not in any flexion angle. As varus knees are not all alike, a uniform surgical technique will not treat all varus knees adequately and the individual gap sizes need to be analyzed and addressed accordingly with an individualized balancing technique. Which final balancing goal should be achieved needs to be analyzed in future studies.

LEVEL OF EVIDENCE

Level III.

Deconstructing the Minimum Clinically Important Difference (MCID)

Purpose

Methods

Results

Conclusion

Patient-Reported Quality of Life Before and After Total Knee Arthroplasty: A Multicenter Observational Study

PURPOSE

To compare patients' self-reported health-related quality of life (HRQoL) before and after total knee arthroplasty (TKA) and determine factors contributing to any heterogeneity in HRQoL.

PATIENTS AND METHODS

This prospective multicenter observational study included 404 patients with knee osteoarthritis who underwent TKA between April 1, 2019 and December 30, 2019 and whose HRQoL was assessed preoperatively and 7 days and 1, 3, and 6 months postoperatively. Sociodemographic characteristics were assessed using a General Information Questionnaire, disability using the Knee Injury and Osteoarthritis Outcome Score (KOOS-PS), resting pain using the visual analogue scale (Pain-VAS), and HRQoL using the European Quality of Life Five Dimension Five Level (EQ-5D-5L) scale. The growth mixture model was used to identify group heterogeneity in the developmental trajectories of KOOS-PS, Pain-VAS, and EQ5D5L. Logistic regression was used to explore the factors influencing the developmental trajectories of factors affecting the developmental trajectory of HRQoL.

RESULTS

The mean EQ-5D-5L score improved from 0.69 preoperatively to 0.90 at 6 months postoperatively. Longitudinal heterogeneity in HRQoL was observed in patients during recovery: 1) patients with a small and slow improvement in HRQoL and 2) patients who showed marked and rapid improvement in HRQoL. The main characteristics of the latter group were decreasing VAS pain scores, a monthly family income >2000 CNY (100 CNY equals approximately 14.9 USD), exercising for <30 min daily, and better knee function at baseline. Baseline knee function and change in knee function were significantly associated with the percentage change in HRQoL.

CONCLUSION

HRQoL improved considerably after TKA. However, there was heterogeneity in the changes in HRQoL depending on patients' socioeconomic status, exercise, and baseline knee function. Dynamic tracking of the HRQoL of TKA patients and timely provision of rehabilitation guidance will promote continuous improvement of the HRQoL of TKA patients.

Measurement properties of UCLA Activity Scale for hip and knee arthroplasty patients and translation and cultural adaptation into Danish

Background and purpose - The UCLA Activity Scale (UCLA) is a questionnaire assessing physical activity level from 1 (low) to 10 (high) in patients undergoing hip or knee arthroplasty (HA/KA). After translation and cultural adaptation, we evaluated the measurement properties of the Danish UCLA.Patients and methods - After dual panel translation, cognitive interviews were performed among 55 HA/KA patients. An orthopedic surgeon and a physiotherapist estimated UCLA scores for 80 KA patients based on short interviews. Measurement properties were evaluated in 130 HA and 134 KA patients preoperatively and 1-year postoperatively.Results - To suit Danish patients of today, several adaptations were required. Prior to interviews, 4 patients were excluded, and 11 misinterpreted the answer options. Examiners rated the remaining 65 patients (mean age 67 years) 0.2-1.6 UCLA levels lower than patients themselves. The 130 HA and 134 KA patients (mean age 71/68 years) changed from 4.3 (SD 1.9)/4.5 (1.8) preoperatively to 6.6 (1.8)/6.2 (1.0) at 1-year follow-up. 103 (79%) HA and 89 (66%) KA patients reported increased activity. Effect sizes were large (1.2/0.96). Knee patients reaching minimal important change (MIC, ≥ 8 Oxford Knee Score points) had higher 1-year UCLA scores than patients not reaching MIC.Interpretation - Original scale development was undocumented. Content validity was questionable, and there was discrepancy between patient and examiner estimates. UCLA appears valuable for measuring change in self-reported physical activity on a group level. 4 out of 5 HA patients and 2 out of 3 KA patients were more physically active 1 year after joint replacement surgery.

Patellar Resurfacing Does Not Improve Clinical Outcome in Patients with Symptomatic Tricompartmental Knee Osteoarthritis. An RCT Study of 40 Patients Receiving Primary Cruciate Retaining Total Knee Arthroplasty

There is some evidence that patellofemoral (PF) joint osteoarthritis (OA) causes anterior knee pain (AKP) after total knee arthroplasty (TKA). We hypothesized that patellar resurfacing in primary TKA for patients with symptomatic tricompartmental knee OA yields better clinical results after 2 years than non-resurfacing. A single center randomized controlled clinical trial comparing 40 patients receiving 42 cruciate retaining TKAs with (n = 21) or without patellar resurfacing (n = 21) was conducted. Primary outcome was the specific PF joint score HSS Baldini and secondary outcomes were the Knee Society Score (KSS) and the Knee Osteoarthritis Outcome Scale (KOOS). After 2 years no significant differences between both groups and between the groups in time for HSS Baldini, KSS, and KOOS were found. HSS Baldini score improved significantly after 6 weeks in both groups (p < 0.001) and did not improve in time afterward. At final follow-up the HSS Baldini mean score improved from a preoperative mean of 39 to 88 (difference of 49 points; p < 0.001)) for without patellar resurfacing group, and from a preoperative mean of 37 to 81 for patellar resurfacing group (difference of 47 points; p < 0.001). One patient in the patellar resurfacing group underwent a soft tissue re-alignment procedure because of patellar subluxation. Two patients in without patellar resurfacing group received secondary patellar button placement. Patellar resurfacing in primary TKA for patients with symptomatic tricompartmental OA has no beneficial effect over non-resurfacing and seems unnecessary. A special PF joint outcome measurement tool (HSS Baldini) and common knee scores showed no better knee function or AKP outcomes for with patellar resurfacing over without patellar resurfacing group in time and after 2 years of follow-up.

A Call for a Standardized Approach to Reporting Patient-Reported Outcome Measures: Clinical Relevance Ratio

A shift toward a value-driven health-care model has made prospective collection of patient-reported outcome measures (PROMs) inextricably tied to measuring the success of orthopaedic surgery and patient satisfaction. While progress has been made in optimizing the utilization of PROM data, including establishing appropriate PROMs for a procedure and determining the clinical importance of unique tools, if these PROMs are not accurately analyzed and reported, a proportion of patients who do not reach the clinical thresholds may go unnoticed. Furthermore, parameters are unclear for setting a statistically and clinically important PROM threshold along with a minimum period for follow-up data collection.In this forum, we walk through simulated data sets modeling PROMs with the example of total joint arthroplasty. We discuss how the commonly used method of reporting PROMs by mean change can overestimate the treatment effects for the cohort as a whole and fail to capture distinct populations that are below a clinically relevant threshold. We demonstrate that when a study's outcome is PROMs, clinical importance should be reported using clinical thresholds such as the minimum clinically important difference (MCID), the smallest change in the treatment outcome that a patient perceives as beneficial, and the patient acceptable symptom state (PASS), the highest level of symptoms beyond which a patient considers himself or herself well. Finally, we propose a standardized reporting of PROMs that incorporates both the MCID and the PASS, and introduce a "clinical relevance ratio," which relies on a clinically relevant threshold to dichotomize outcomes and reports the number of patients achieving clinical importance at a given time point divided by the total number of patients included in the study. Unlike other common PROM-reporting approaches, the clinical relevance ratio is not skewed by patients who are lost to follow-up with increased time.

The minimal clinically important difference of the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and upper extremity computer adaptive tests and QuickDASH in the setting of elbow trauma

Background

Minimal clinically important difference (MCID) estimates are useful for gauging clinical relevance when interpreting changes or differences in patient-reported outcomes scores. These values are lacking in the setting of elbow trauma. Our primary purpose was to estimate the MCID of the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) computer adaptive test (CAT), the PROMIS upper extremity (UE) CAT, and the QuickDASH using an anchor-based approach for patients recovering from elbow trauma and related surgeries. Secondarily, we aimed to estimate the MCID using the 1/2 standard deviation method.

Materials & methods

Adult patients undergoing treatment for isolated elbow injuries between July 2014 and April 2020 were identified at a single tertiary academic medical center. Outcomes, including the PROMIS PF CAT v1.2/2.0, PROMIS UE CAT v1.2, and QuickDASH, were collected via a tablet computer. For inclusion, baseline (6 months before injury up to 11 days postoperatively or after injury) and follow-up (11 to 150 days postoperative or after injury) PF or UE CAT scores were required, as well as a response to an anchor question querying improvement in physical function. The MCID was calculated using (1) an anchor-based approach using the difference in mean score change between anchor groups reporting “No change” and “Slightly Improved/Improved” and (2) the 1/2 standard deviation method.

Results

Of the 146 included patients, the mean age was 46 ± 18 years and 67 (46%) were women. Most patients (129 of 146 or 88%) were recovering from surgery, and the remaining 12% were recovering from nonoperatively managed fractures and/or dislocations. The mean follow-up was 157 ± 192 days. Scores for each instrument improved significantly between baseline and follow-up. Anchor-based MCID values were calculated as follows: 5.7, 4.6, and 5.3 for the PROMIS PF CAT, PROMIS UE CAT, and QuickDASH, respectively. MCID values estimated using the 1/2 standard deviation method were 4.3, 4.8, and 11.7 for the PROMIS PF CAT, PROMIS UE CAT, and QuickDASH, respectively.

Conclusions

In the setting of elbow trauma, we propose MCID ranges of 4.3 to 5.7 for the PROMIS PF CAT, 4.6 to 4.8 for the PROMIS UE CAT, and 5.3 to 11.7 for the QuickDASH. These values will provide a framework for clinical relevance when interpreting clinical outcomes studies, or powering clinical trials, for populations recovering from trauma.

Comparison of patient reported outcome measures after single versus two-stage revision for chronic infection of total hip arthroplasty: a retrospective propensity score matched cohort study

INTRODUCTION

Two-stage revision is the current gold standard treatment for infected total hip arthroplasties (THA) with good clinical outcomes. Single-stage revision THA offers the advantage of only a single surgical intervention, potentially leading to improved functional outcomes. This study aimed to compare the differences in patient-reported outcome measures (PROMs) and complications between single and two-stage revision THA for chronic periprosthetic joint infection (PJI).

METHODS

A total of 159 consecutive revision THA patients for chronic PJI with complete pre-and post-operative patient-reported outcome measures (PROM) was investigated. A total of 46 patients with single-stage revision THA was matched to 92 patients following two-stage revision THA using propensity score matching, yielding a total of 136 propensity score-matched patients for analysis.

RESULTS

Single and two-stage revision THA improved PROM scores post-operatively, with significantly higher PROMs for single-stage revision THA (HOOS-PS: 50.7 vs 46.4, p = 0.04; Physical SF 10A: 42.1 vs 36.6, p < 0.001; PROMIS SF Physical: 41.4 vs 37.4, p < 0.001; PROMIS SF Mental: 52.8 vs 47.6, p < 0.001). There was no significant difference between both cohorts for reinfection rates (p = 0.81) and 90-day mortality rates (p = 1.0).

CONCLUSION

This study found a demonstrable functional benefit of single-stage revision compared to two-stage revision for THA with chronic periprosthetic joint infection, suggesting that single-stage revision THA may provide an effective alternative to two-stage revision in selected patients with chronic PJI.

LEVEL OF EVIDENCE

Level III, case-control retrospective analysis.

Cycle Sprint Test for the Evaluation of Lower Limb Muscle Power After Total Knee Arthroplasty: A Proof-of-Concept Study

Background

Lower limb muscle power is emerging as an important determinant of patient function after knee injury or surgery. This study tested proof of concept of a cycle sprint test for the evaluation of lower limb muscle power, as an outcome measure for patients having total knee arthroplasty (TKA).

Methods

Thirty-two patients were enrolled, of which 16 completed all follow-ups (3, 6, and 12 months). All patients completed the Oxford Knee Score and Knee Injury and Osteoarthritis Outcome Score questionnaires, a 10-m walk test, and 30-second sit-stand test. A trainer-mounted road cycle fitted with an instrumented crank was used for the cycle sprint test. Maximum muscle power was measured from 3, 10-second maximal efforts.

Results

Significant improvements in Oxford Knee Score and Knee Injury and Osteoarthritis Outcome scores relative to baseline were achieved at each follow-up (P < .001), and functional test performance improved significantly at 6 and 12 months (P < .001). Compared with the baseline of 268W, muscle power was significantly lower at 3 months (239W, −13%, P < .05) and significantly higher at 12 months (308W, +12%, P < .05).

Conclusion

The concept of muscle power measurement using a cycle sprint test before and after TKA has been demonstrated in this study. Identification of individuals with lower limb muscle power deficits after TKA may inform rehabilitation programs and enhance long-term outcomes.

Mid-term functional outcomes of patient-specific versus conventional instrumentation total knee arthroplasty: a prospective study

INTRODUCTION

Patient-specific instrumentation (PSI) utilizes three-dimensional imaging to produce total knee arthroplasty cutting jigs which matches patient's native anatomy. However, there are limited mid- to long-term studies examining its clinical efficacy. The aim of this study was to compare functional outcomes of PSI surgery versus conventional TKA surgery at 5-year follow-up.

MATERIALS AND METHODS

Sixty patients were prospectively recruited into either the MRI-based PSI or conventional TKA group. Functional outcomes were assessed using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS) and Oxford Knee Score (OKS), while quality of life was evaluated with the Physical Component Score (PCS) and Mental Component Score (MCS) of Short-Form 36 and compared between the two groups at 5-year follow-up.

RESULTS

Although the PCS was 7 ± 3 points better in the PSI group preoperatively (p = 0.017), it became 5 ± 2 points worse than the conventional group at 5-year follow-up (p = 0.025). As compared to the PSI group, the conventional group showed a significantly greater improvement in PCS at 5 years as compared to before surgery (p = 0.003). There were no significant differences in KSFS, KSKS, OKS or MCS between the two groups.

CONCLUSIONS

PSI TKA did not result in improved functional outcomes or better quality of life when compared to conventional TKA. The additional costs and waiting time associated with PSI are not justifiable and therefore not recommended as an alternative to conventional TKA.

LEVEL OF EVIDENCE

II.

Patient-reported assessment of outcome after surgery for bone metastases

Regardless of prognosis, surgery is often considered in metastatic bone disease (MBD) as a palliative procedure to improve function and quality of life. Traditional focus on objective outcomes such as mortality is inappropriate in this group, and there is a drive to assess outcomes via patient-reported outcome measures (PROMs). This is an overview of current understanding of MBD outcomes and how this should influence future decision-making and research. The objectives of this review were to identify difficulties in measuring PROMs in the MBD patient population and explore alternatives to patientreported outcomes. We also provide an overview of current understanding of outcomes in MBD and how this should influence decision-making and direct research.

Quantifying Achievable Levels of Improvement in Knee Joint Biomechanics During Gait After Total Knee Arthroplasty Relative to Osteoarthritis Severity

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.

Revision total knee arthroplasty versus primary total knee arthroplasty: a matched cohort study

Introduction

The primary aim of this study was to describe a baseline comparison of early knee-specific functional outcomes following revision total knee arthroplasty (TKA) using metaphyseal sleeves with a matched cohort of patients undergoing primary TKA. The secondary aim was to compare incidence of complications and length of stay (LOS) between the two groups.

Methods

Patients undergoing revision TKA for all diagnoses between 2009 and 2016 had patient-reported outcome measures (PROMs) collected prospectively. PROMs consisted of the American Knee Society Score (AKSS) and Short-Form 12 (SF-12). The study cohort was identified retrospectively and demographics were collected. The cohort was matched to a control group of patients undergoing primary TKA.

Results

Overall, 72 patients underwent revision TKA and were matched with 72 primary TKAs with a mean follow-up of 57 months (standard deviation (SD) 20 months). The only significant difference in postoperative PROMs was a worse AKSS pain score in the revision group (36 vs 44, p = 0.002); however, these patients still produced an improvement in the pain score. There was no significant difference in improvement of AKSS or SF-12 between the two groups. LOS (9.3 days vs 4.6 days) and operation time (1 hour 56 minutes vs 1 hour 7 minutes) were significantly higher in the revision group (p < 0.001). Patients undergoing revision were significantly more likely to require intraoperative lateral release and postoperative urinary catheterisation (p < 0.001).

Conclusion

This matched-cohort study provides results of revision TKA using modern techniques and implants and outlines what results patients can expect to achieve using primary TKA as a control. This should be useful to clinicians counselling patients for revision TKA.

Self-Reported and Performance-Based Outcome Measures Estimation Using Wearables After Unilateral Total Knee Arthroplasty

Total knee arthroplasty is a common surgical treatment to improve ambulatory function for individuals with end-stage osteoarthritis of the knee. Functional and self-reported measures are widely used to assess functional ability and impairment before and after total knee arthroplasty. However, clinical assessments have limitations and often provide subjective and limited information. Seamless gait characteristic monitoring in the real-world condition is a viable alternative to address these limitations, but the effectiveness of using wearable sensors for knee treatment is unclear. The purpose of this study was to determine if inertial gait variables from wearable sensors effectively estimate the questionnaire, performance (6-min walk test, timed up and go, and 30-s chair stand test), and isometric measure outcomes in individuals after unilateral total knee arthroplasty. Eighteen subjects at least 6 months post-surgery participated in the experiment. In one session, three tasks, including self-reported surveys, functional testing, and isometric tests were conducted. In another session, the participants' gait patterns were measured during a 1-min walking test at their self-selected gait speed with two accelerometers worn above the lateral malleoli. Session order was inconsistent between subjects. Significant inertial gait variables were selected using stepwise regressions, and the contributions of different categories of inertial gait variables were examined using hierarchical regressions. Our results indicate inertial gait variables were significantly correlated with performance test and questionnaire outcomes but did not correlate well with isometric strength measures. The findings demonstrate that wearable sensor-based gait analysis may be able to help predict clinical measures in individuals after unilateral knee treatment.

Associations between comorbidity and quality of life outcomes after total joint replacement

PURPOSE

We examined associations between self-reported and clinician-assessed comorbidity and quality of life (QOL) outcomes after hip and knee replacement.

METHODS

This is a cross-sectional, questionnaire-based national survey. Participants aged 45 years or older (n = 409) were recruited from the New Zealand Joint Registry six months after a total hip (THR), total knee (TKR) or unicompartmental knee replacement (UKR). The main outcome QOL was measured using an 8-item short form of the World Health Organisation Quality of Life (WHOQOL-Bref) questionnaire six months following joint replacement surgery. The WHOQOL is a generic and non-health condition specific measure of QOL.

RESULTS

Participants were on average 68 years of age, with more men (54%) than women (46%). Number of coexisting conditions and body mass index were correlated with age, pain and function scores, and QOL (p < 0.01), but not with each other. Linear regression analyses showed that comorbidities such as number of comorbid conditions and BMI had moderate associations with QOL outcomes.

CONCLUSION

This study showed that general QOL outcomes following hip and knee joint replacement, while generally high, were associated with comorbidity burden and BMI. Future prospective research examining change in QOL before and following surgery would help to advance understandings of the various factors that contribute to patient satisfaction with their joint replacement.

Translation and Validation of Forgotten Joint Score for Total Hip Arthroplasty for Indian Population

BACKGROUND

The ultimate success of a total hip replacement lies in patients forgetting about their artificial joints during routine activities. "Forgotten Joint Score (FJS)" is emerging as an important tool in assessing outcomes of total hip arthroplasty. There has been no version of this score available in commonly spoken vernaculars in India. This study aims to formulate and validate the Hindi version of FJS in Indian population.

METHODS

A total of 136 patients with a minimum follow-up of 6 months and a maximum follow-up of 18 months after total hip arthroplasty were asked to fill the translated and adapted version of FJS questionnaire, at two points of time 2 weeks apart. The Hindi version of FJS (I-FJS) was tested for reliability and responsiveness, floor and ceiling effect and validity against modified Harris Hip Score (mHHS). Construct validity was expressed as the Pearson correlation coefficient. Internal consistency was expressed as Cronbach's alpha and test-retest reliability as the intra-class correlation coefficient (ICC).

RESULTS

I-FJS showed excellent internal consistency with Cronbach's alpha of 0.88. Intra-class correlation coefficient (ICC) was 0.94. I-FJS showed good correlation with m-HHS (r = 0.8, p = 0.001). The standard error of measurement was 3.6 and the smallest detectable change was 9.97. There was no floor or ceiling effect observed with I-FJS. Data from this study were insufficient to establish adequate responsiveness of I-FJS.

CONCLUSION

I-FJS is a valid, reliable and reproducible score for hip function in post-THA patients. It is devoid of any floor or ceiling effect. Hindi version of FJS could be an effective tool for studying hip function in the Indian population.

Responsiveness, Reliability, and Validity of Arabic Version of Oxford Knee Score for Total Knee Arthroplasty

BACKGROUND

The Oxford Knee Score (OKS) is a reliable, valid, and sensitive assessment tool for individuals undergoing a total knee arthroplasty (TKA). The published psychometric assessment of the Arabic version of the OKS (OKS-Ar) is limited to male patients and has not been assessed for responsiveness following TKA. The aim of this study was to assess the reliability, validity, and responsiveness of the OKS-Ar in an inclusive population of patients undergoing TKA.

METHODS

One hundred Arabic-speaking patients awaiting TKA were assessed with the OKS-Ar, the Arabic version of the Knee injury and Osteoarthritis Outcome Score (KOOS-Ar), and a visual analogue scale for pain (VAS-P) in order to assess the correlation between the OKS-Ar and the KOOS-Ar and VAS-P and determine the construct validity. Repeat assessments were completed 7 to 10 days after the first assessment and 6 months after TKA.

RESULTS

Questionnaires were completed by 80 female and 20 male participants with a mean age of 62 ± 8 years. The test and retest median scores showed no significant difference from one another, with a strong Spearman correlation between the 2 measurements (rs = 0.94). Bland-Altman limits of agreement showed no significant bias. The Cronbach alpha was 0.85 indicating high internal consistency. There was no floor or ceiling effect before TKA, and the post-TKA ceiling effect was only 2%. The OKS-Ar pain component correlated strongly with the KOOS-Ar pain subscale (rs = 0.73). The OKS-Ar effect size was 3.09, which was larger than that of all of the KOOS subscales at 6 months after TKA.

CONCLUSIONS

To our knowledge, this is the first study to assess reliability, validity, and responsiveness of the OKS-Ar after TKA. The validity and reliability results are similar to those found for both the original English-language OKS and the OKS translated into other languages. We believe that this is also the first study to assess OKS-Ar responsiveness after TKA and to show a large effect size. We found that the OKS-Ar is a feasible, valid, reliable, and sensitive measurement tool to assess pain and function in TKA-treated individuals whose main language is Arabic.

Outcome reporting patterns in total knee arthroplasty: A systematic review

BACKGROUND

Total knee arthroplasty (TKA) is one of the most effective ways to treat end-stage painful conditions of the knee. However, non-standardized reporting patterns can make quantitative analysis of patient outcomes difficult.

METHODS

A systematic review of the literature was performed using keywords "total knee arthroplasty" and "total knee replacement." Randomized controlled trials (RCTs) meeting the inclusion criteria were sorted and reviewed. Type of study, outcome measures used to report their results, and the actual results were recorded. Quantitative analysis was performed.

RESULTS

A total of 233 RCTs were included. There was significant variability in the reporting of short term and long term outcomes in total knee arthroplasty. The most common treatment domains in order of decreasing frequency were objective knee function, subjective knee function, perioperative complications, and pain. Range of motion was the most common outcome metric reported in all the RCTs and also was the most common metric used to assess objective knee function. The most common patient reported outcome measure used to assess postoperative function was the Knee Society Score followed by Knee Injury and Osteoarthritis Outcome Score. The Visual Analog Scale was the most common measurement tool used to assess postoperative pain. Most studies assessed patient outcomes in three treatment domains. None reported outcomes in all seven domains.

CONCLUSION

There is significant variability in outcome reporting patterns in TKA literature. Most studies do not track outcomes comprehensively, with a significant minority of the RCTs tracking outcomes in only one treatment domain.

Psychosocial predictors of outcomes up to one year following total knee arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) aims to relieve pain and improve physical functioning of the knee, however, some patients continue to experience pain and impaired function following TKA which cannot be explained by surgical and implant factors. Psychological factors may influence the outcomes of TKA. The aim of this prospective study was to examine the psychosocial factors that predicted pain, stiffness and physical functioning up to one year following TKA.

METHODS

One hundred and two patients completed pre-operative and one-year questionnaires which assessed a wide range of psychosocial and sociodemographic factors prior to surgery. The Oxford Knee Score (OKS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, Stiffness and Physical Functioning subscales were used as outcome measures. Pearson correlation analysis and multiple linear regression were conducted to examine relationships between predictor and outcome variables.

RESULTS

Regression analysis showed that regarding variance in WOMAC outcome measures post TKA, our model predicted 31% for physical functioning, 25% for pain and 29% for stiffness at one year. Regarding variance in OKS post TKA, the model predicted 36% at one year. Greater levels of depressive symptoms and neuroticism and worse pre-operative scores significantly predicted poorer outcomes.

CONCLUSIONS

The findings indicate that pre-operative psychosocial factors are important in understanding outcomes of TKA. Psychosocial factors could be considered during pre-operative assessment. Further research conducted on psychological interventions is needed within this population to determine whether early and one-year outcomes can be improved.

The Minimal Clinically Important Difference of the PROMIS and QuickDASH Instruments in a Nonshoulder Hand and Upper Extremity Patient Population

PURPOSE

The minimal clinically important difference (MCID) is used in research and clinical settings as a benchmark to gauge improvement following treatment. The purpose of this study was to provide anchor-based MCID estimates for Patient-Reported Outcomes Measurement Information System (PROMIS) and legacy instruments in a nonshoulder hand and upper extremity population.

METHODS

Adult patients (≥18 years) seeking care at a tertiary academic outpatient hand surgery clinic completed patient-reported outcome measures on tablet computers between January 2015 and August 2017. Data were collected at baseline and at 6 ± 2 weeks of follow-up. The PROMIS Upper Extremity (UE), Physical Function (PF), and Pain Interference (PI) Computer Adaptive Test (CAT) instruments were administered, along with the shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH). A mean change anchor-based method was used to estimate MCIDs by comparing scores between anchor groups reporting no change versus slightly improved in terms of function and pain.

RESULTS

Scores for each instrument significantly improved over the study period. With significant differences in scores between groups reporting no change and slightly improved function, anchor-based MCID estimates were calculated as follows: 2.1 for the PROMIS UE CAT, 1.7 for the PROMIS PF CAT, and 6.8 for the QuickDASH. There was no significant difference in PROMIS PI CAT scores between anchor groups when queried for level of pain improvement, precluding estimation of an anchor-based MCID.

CONCLUSIONS

We have provided anchor-based MCID estimates for the PROMIS UE CAT, PROMIS PF CAT, and the QuickDASH for a general nonshoulder hand and upper extremity population. These values may be useful in future research for informing power calculations and when interpreting whether the magnitude of change on these instruments is clinically significant at a population level.

CLINICAL RELEVANCE

This study provides clinicians with a reference for values that may reflect clinically meaningful changes in scores for patient-reported outcome instruments commonly utilized in the current hand surgery literature.

Patient-Reported Outcome Measures are not a Valid Proxy for Patient Satisfaction in Total Joint Arthroplasty

BACKGROUND

Patient-reported outcome measures (PROMs) are increasingly used as quality benchmarks in total joint arthroplasty. The objective of this study is to investigate whether PROMs correlate with patient satisfaction, which is arguably the most important and desired outcome.

METHODS

Our institutional joint database was queried for patients who underwent primary, elective, unilateral total joint arthroplasty. Eligible patients were asked to complete a satisfaction survey at final follow-up. Correlation coefficients (R) were calculated to quantify the relationship between patient satisfaction and prospectively collected PROMs. We explored a wide range of PROMs including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form-12, Oxford Hip Score, Knee Society Clinical Rating Score (KSCRS), Single Assessment Numerical Evaluation, and University of California Los Angeles activity level rating.

RESULTS

In general, there was only weak to moderate correlation between patient satisfaction and PROMs. Querying the absolute postoperative scores had higher correlation with patient satisfaction compared to either preoperative scores or net changes in scores. The correlation was higher with disease-specific PROMs (WOMAC, Oxford Hip Score, KSCRS) compared to general health (Short Form-12), activity level (University of California Los Angeles activity level rating), or perception of normalcy (Single Assessment Numerical Evaluation). Within disease-specific PROMs, the pain domain consistently carried the highest correlation with patient satisfaction (WOMAC pain subscale, R = 0.45, P < .001; KSCRS pain subscale, R = 0.49, P < .001).

CONCLUSION

There is only weak to moderate correlation between PROMs and patient satisfaction. PROMs alone are not the optimal way to evaluate patient satisfaction. We recommend directly querying patients about satisfaction and using shorter PROMs, particularly disease-specific PROMs that assess pain perception to better gauge patient satisfaction.

Gait quality assessed by trunk accelerometry after total knee arthroplasty and its association with patient related outcome measures

BACKGROUND

With an increasingly younger population and more active patients, assessment of functional outcome is more important than ever in patients undergoing total knee arthroplasty. Accelerometers have been used successfully to objectively evaluate gait quality in other fields. The aim of this study was to assess gait quality with accelerometers before and after surgery, and to assess added value of resulting parameters to patient reported outcome measures scores.

METHODS

Sixty-five patients (mean age 65 years (range 41-75)) who underwent primary total knee arthroplasty were evaluated using a tri-axial trunk accelerometer preoperatively and 1 year after surgery. Gait quality parameters derived from the accelerometry data were evaluated in three dimensions at both time points. Factor analysis was performed on all outcome variables and changes from before to 1 year after surgery in the most representative variable for each factor were studied.

FINDINGS

Factor analysis identified three separate gait quality factors, with questionnaire and gait quality parameters loading on different factors. Both gait quality factor scores and questionnaire factor scores improved significantly 1 year after surgery. As expected based on the factor analysis, only weak to moderate associations were found between patient reported outcome measures and gait quality before surgery, after surgery and in change scores.

INTERPRETATION

The independence of patient reported outcome measures and gait quality parameters measured with trunk accelerometry indicates that gait quality parameters provide additional information on functional outcome after total knee arthroplasty. Providing caretakers with objectively measurable targets using accelerometry could help improve outcome of these patients.

Patient-reported outcome measures in total joint arthroplasty: defining the optimal collection window

Background

The purpose of this study was to determine the optimal window for collection of patient-reported outcome measures (PROMs) after total joint arthroplasty (TJA).

Methods

Our prospectively collected institutional joint registry was queried for patients who underwent primary, unilateral TJAs. The primary outcomes were the net changes in WOMAC, SF-12 MCS, SF-12 PCS, OHS, KSCRS, and UCLA activity rating system at 6, 12, and 24 months postoperatively. Secondary outcomes were data acquisition costs and follow-up attrition rates.

Results

Eight hundred sixty-six procedures (450 total hip arthroplasties, 416 TKAs) were analyzed. A consistent plateau in all PROMs was noted by 6 months postoperatively–except for SF-12 MCS which showed no significant changes at any time interval. For TKA, the percentage of overall improvement achieved by 6 months was 88.7%, 84.5%, 100%, and 90.5% for the WOMAC, SF-12 PCS, UCLA, and KSCRS, respectively. For total hip arthroplasty, these values were 92.7%, 83.5%, 88.0%, and 89.8% for WOMAC, SF-12 PCS, UCLA, and OHS, respectively. There were marginal improvements from 6 to 12 months and no improvement from 12 to 24 months. Follow-up rates at 6, 12, and 24 months were 85%, 69%, and 40%, respectively. Our institutional costs for collecting a complete data set per patient were $128, $158, and $272 for 6, 12, and 24 months, respectively.

Conclusions

Most of the improvement in PROMs after primary TJA occurs within the first 6 months. In addition, limiting PROMs collection to 6 months appears to be cost-efficient owing to increased attrition rates beyond this time interval.

Are priorities of younger patients with knee pain addressed by PROMs? A qualitative study

OBJECTIVES

To describe the impact of knee pain and dysfunction in young adults and determine whether current patient reported outcome measures (PROMs) address their recovery priorities.

DESIGN

Qualitative.

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Young adults, 23-30 years.

MAIN OUTCOME MEASURES

1:1 semi-structured interviews were held and analyzed with NVivo version 11. The Lower Extremity Functional Scale (LEFS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) were compared to participant identified functional limitations.

RESULTS

9 themes were identified in 7 interviews: Incomplete Recovery as Acceptable, Motivation for Adequate Long Term Function, Guidance Needed to Facilitate Recovery, Sports: To Play or Not to Play, Pain, Therapy Participation and Interventions, Impact on Life, Decreased Knowledge and Condition Management, and A Wide Range of Functional Limitations. The LEFS captured 23/26 identified functional activities, the KOOS 22/26, the IKDC 16/26, and the WOMAC 13/26.

CONCLUSIONS

Incomplete recovery as an acceptable outcome was the most unique theme found in this study. LEFS captured the most relevant functional activities reported by this group. Physical Therapists should consider these findings in PROM selection to better inform meaningful outcome measurement.

No difference in joint awareness after TKA: a matched-pair analysis of a classic implant and its evolutional design

PURPOSE

Total knee arthroplasty (TKA) designs continuously evolve with the aim of improving patient outcomes. The purpose of the current study was to compare clinical and patient-reported outcome (PRO) results of a new TKA implant to its predecessor. The hypothesis of this study was that joint awareness and range of motion (ROM) of the newer design would be better than the classic design.

METHODS

One hundred patients undergoing TKA using the newer design (Attune^®) were matched by age and gender to 200 patients with the classic design (LCS^®). All patients underwent computer-navigated (Vector Vision, Brain-Lab, Germany) primary TKA by the same surgeon using the same technique. Data (FJS-12, WOMAC and ROM) were collected preoperatively and at 12 months follow-up at our implant registry.

RESULTS

Compared to preoperative scores, FJS-12, WOMAC and ROM improved significantly at 12 months follow-up. In the Attune group, mean FJS-12 and WOMAC at follow-up were 67.6 (SD 27.8) and 14.8 (SD 14.9) respectively, compared to 70.8 (SD 33.8) and 15 (SD 17.9) in the LCS group. Mean postoperative ROM was similar in both groups (Attune 120°, range 90°-140°, SD 10.4 and LCS 120°, range 85°-140°, SD 10.3).

CONCLUSION

The newer TKA and the predecessor design achieved comparable joint awareness, WOMAC scores and ROM at 1-year follow-up. The benefits expected of the newer design could not be observed in early clinical and PROs. The clinical relevance of this study is that it questions the importance of implant design as the single most important factor for patient outcomes.

LEVEL OF EVIDENCE

III.

Are modern knee outcomes scores appropriate for evaluating patellofemoral degeneration in osteoarthritis? Evaluation of the ceiling and floor effects in knee outcomes scores

INTRODUCTION

Patellofemoral (PF) degeneration plays an important role in knee function in the context of osteoarthritis. A specific evaluation of PF symptoms is needed to better understand the initial functional status of the knee before surgery. The aim of this study was to assess the validity of patient-related outcome measures (PROMs) for knee scores and PF scores in knee osteoarthritis.

HYPOTHESIS

PF scores are more reliable for evaluating anterior knee pain than global knee scores in the context of PF degeneration in osteoarthritis.

MATERIAL AND METHODS

We performed a prospective single-center study of continuous patients included between January 2017 and January 2018 in our surgical department for total knee arthroplasty (TKA) for primary knee osteoarthritis. The analysis used global knee PROMs (KOOS and new IKS) and PF-specific PROMs (HSS Patella score, Kujala score and Lille score). Floor and ceiling effects were determined for each score based on tibiofemoral and PF degeneration on radiographic views; it was considered significant when greater than 15%.

RESULTS

We included 114 TKA procedures in 113 consecutive patients. According to the Iwano classification, no significant floor or ceiling effect was found for the PF preoperative scores (0-12%). The KOOS ADL and QOL scores were particularly affected by the ceiling and floor effects, whatever the patellofemoral degeneration (23-88%). In cases of severe PF degeneration (Iwano grade 3 and 4), no significant differences in the distribution of the functional scores were found.

DISCUSSION

Modern knee outcome scores used to evaluate knee function do not monitor PF degeneration and related symptoms in the context of knee osteoarthritis according to the Iwano classification. PF scores do not have a floor and ceiling effects even if the severity of the PF degeneration is difficult to identify preoperatively. Physicians should be aware of this effect on the preoperative functional evaluation before TKA.

LEVEL OF EVIDENCE

III, comparative prospective study.

Can the Oxford Knee and Hip Score identify patients who do not require total knee or hip arthroplasty?

Aims

The aim of this study was to determine if the Oxford Knee and Hip Score (OKHS) can accurately predict when a primary knee or hip referral is deemed nonsurgical versus surgical by the surgeon during their first consultation, and to identify nonsurgical OKHS screening thresholds.

Patients and Methods

We retrospectively reviewed pre-consultation OKHS for all consecutive primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) consultations of a single surgeon over three years. The 1436 knees (1016 patients) and 478 hips (388 patients) included were categorized based on the surgeon’s decision into those offered surgery during the first consultation versus those not (nonsurgical). Spearman’s rank correlation coefficients and receiver operating characteristic (ROC) curve analysis were performed.

Results

Oxford Scores were better for the nonsurgical cohorts (p < 0.001) and correlated with the surgical decision (p < 0.001). ROC area under the curve values for knees (0.83, 95% confidence intervals (CI) 0.81 to 0.85) and hips (0.87, 95% CI 0.84 to 0.91) were excellent. A conservative and effective threshold for knees is Oxford Knee Score (OKS) > 32 points (sensitivity = 0.997, negative predictive value (NPV) = 0.992) and for hips is Oxford Hip Score (OHS) > 34 points (sensitivity = 0.997, NPV = 0.978). Severable potential lower OKHS thresholds were identified.

Conclusion

Pre-consultation OKHS demonstrate good ability to predict when a primary TKA or THA referral will be deemed nonsurgical in a single surgeon’s practice. Multiple OKHS thresholds can effectively screen out nonsurgical referrals. Cite this article: Bone Joint J 2019;101-B(6 Supple B):23–30.

Relationship Between the Patient-Reported Outcome Measurement Information System and Traditional Patient-Reported Outcomes for Osteoarthritis

BACKGROUND

Incorporating patient-reported outcomes (PROs) is paramount to the creation of a value-based healthcare system that prioritizes patient-centered care in total joint arthroplasty. The relationship between global assessment PROs such as Patient-Reported Outcome Measurement Information System (PROMIS) and joint-specific PROs for hip and knee, such as short form variations of Knee Injury and Osteoarthritis Outcome Score (KOOS-JR) and Hip Injury and Osteoarthritis Outcome Score (HOOS-JR), has yet to be assessed.

METHODS

A retrospective analysis was conducted to assess PRO measurements for knee-related and hip-related complaints. The KOOS-JR and HOOS-JR were compared to the PROMIS computerized adaptive test (CAT) short forms (physical function, pain interference, and pain intensity) to assess their relationship.

RESULTS

A total of 3644 patients completed 4609 questionnaires. A modest to strong correlation was observed between the KOOS-JR and the PROMIS CAT (ranging from r = 0.56 to -0.71, P < .05). A modest to strong correlation was also found between the HOOS-JR and the PROMIS CAT (r = 0.59 to -0.79, P < .05).

CONCLUSION

PROMIS CATs demonstrated a modest to strong correlation with KOOS-JR or HOOS-JR. Future studies should further investigate the limitations of global assessment health surveys in capturing disease-specific changes following total joint arthroplasty.

Preoperative Quadriceps Muscle Strength and Functional Ability Predict Performance-Based Outcomes 6 Months After Total Knee Arthroplasty: A Systematic Review

BACKGROUND

One-third of individuals report limitations in activities of daily living even 6 months after total knee arthroplasty (TKA). Moderate-quality evidence exists for several sociodemographic and clinical predictors of patient-reported outcome measures of perceived functionality. Objectively measured performance-based measures (PBMs) provide a less subjective approach to informing patient treatment after TKA; however, information about predictors of functionally relevant PBMs is scarce.

PURPOSE

This systematic review synthesized the available research on preoperative predictors of PBMs after primary TKA for osteoarthritis.

DATA SOURCES

In June 2016 and January 2017, MEDLINE, EMBASE, and PsycINFO databases were searched.

STUDY SELECTION

Cohort studies exploring preoperative predictors of stair climbing, walking speed, and gait speed measured ≥6 months after primary TKA were included. Screening of abstracts and selection of full texts were undertaken by 2 independent reviewers.

DATA EXTRACTION

Information on study design, patient characteristics, analysis, and results was extracted using pilot-tested forms. Two independent reviewers assessed risk of bias using modified Quality in Prognostic Studies criteria.

DATA SYNTHESIS

Of the eligible 12 studies involving 6 prospective cohorts, 10 studies reported information on baseline predictors. Meta-analysis of predictors was not possible because of missing information on effect size or standard errors. Narrative synthesis of evidence of predictors was therefore performed.

LIMITATIONS

The quality of evidence was low because of the risk of bias and heterogeneity of included studies as well as nonreporting of measures of effect.

CONCLUSIONS

Low-quality evidence exists for an association of preoperative functional ability and quadriceps muscle strength with functionality at 6 months after TKA. Improved reporting of predictor analyses is needed to enable evidence generation for clinical management.

Current Trends in Patient-Reported Outcome Measures in Total Joint Arthroplasty: A Study of 4 Major Orthopaedic Journals

BACKGROUND

More emphasis is being placed on patient-reported outcome measures (PROMs), but the myriad of PROMs makes standardization and cross-study comparison difficult. As the era of big data and massive total joint registries matures, it will be critical to identify and implement the best PROMs.

METHODS

All abstracts published in the years 2004, 2009, 2014, and 2016 in the Journal of Bone and Joint Surgery-American volume, the Bone and Joint Journal, Clinical Orthopedics and Related Research, and the Journal of Arthroplasty were reviewed. A PubMed search was performed with filters limiting results only to total knee, total hip, and unicompartmental knee arthroplasty articles with available abstracts. Each abstract was reviewed to identify all PROMs. Trends over time were evaluated using the Cochran-Armitage test. In the non-trend analysis, Pearson chi-square tests and one-way analysis of variance were performed.

RESULTS

A total of 42 unique PROMs were used 1073 times across 644 studies. The number of PROMs in these 4 journals increased from 97 in 2004 to 228 in 2016 (P < .0001). The proportion of articles with more than one PROM increased from 20.6% in 2004 to 47.8% in 2016 (P = .0001). The most common PROMs used in total knee, total hip, and unicompartmental knee arthroplasty studies were the Knee Society Score, the Harris Hip Score, and the Oxford Knee Score, respectively.

CONCLUSION

Providers and registries should consider the relative prevalence of published outcome measures when selecting which PROMs to use, to better facilitate future cross-study comparison.

Pre-operative sensor-based gait parameters predict functional outcome after total knee arthroplasty

BACKGROUND

Despite the general success of total knee arthroplasty (TKA) regarding patient-reported outcome measures, studies investigating gait function have shown diverse functional outcomes. Mobile sensor-based systems have recently been employed for accurate clinical gait assessments, as they allow a better integration of gait analysis into clinical routines as compared to laboratory based systems.

RESEARCH QUESTION

In this study, we sought to examine whether an accurate assessment of gait function of knee osteoarthritis patients with respect to surgery outcome evaluation after TKA using a mobile sensor-based gait analysis system is possible.

METHODS

A foot-worn sensor-based system was used to assess spatio-temporal gait parameters of 24 knee osteoarthritis patients one day before and one year after TKA, and in comparison to matched control participants. Patients were clustered into positive and negative responder groups using a heuristic approach regarding improvements in gait function. Machine learning was used to predict surgery outcome based on pre-operative gait parameters.

RESULTS

Gait function differed significantly between controls and patients. Patient-reported outcome measures improved significantly after surgery, but no significant global gait parameter difference was observed between pre- and post-operative status. However, the responder groups could be correctly predicted with an accuracy of up to 89% using pre-operative gait parameters. Patients exhibiting high pre-operative gait function were more likely to experience a functional decrease after surgery. Important gait parameters for the discrimination were stride time and stride length.

SIGNIFICANCE

The early identification of post-surgical functional outcomes of patients is of great importance to better inform patients pre-operatively regarding surgery success and to improve post-surgical management.

Evaluating instrument responsiveness in joint function: The HOOS JR, the KOOS JR, and the PROMIS PF CAT

12345Responsiveness is the ability to detect change over time and is an important aspect of measures used to detect treatment effects. The purpose of this study was to assess the responsiveness of the HOOS JR, the KOOS JR, and the PROMIS Physical Function (PF) computerized adaptive test (CAT) in a joint reconstruction practice. 983 patients were evaluated for joint conditions between 2014 and 2017 in an orthopaedic clinic and completed the three instruments at baseline and 3 and/or 6-month follow-up visits. Average age was 61.03 years (SD = 12.33, Range = 18-90 years) and the majority of the patients were White (n = 875, 89.0%). Three-month responsiveness was calculated two ways, as between 80 and 100 days and as 90 days and beyond. Six-month responsiveness was calculated as 170-190 days and as 180 days and beyond. All changes from baseline scores were significant at the 3-, >3-, and >6-month follow-up (p < 0.05). All three measures showed large effect sizes, ranging from 0.80-1.20 at each time-point. The standardized response mean was large for each measure and at each time-point (Range = 1.06-1.53). This study demonstrated the responsiveness of the HOOS JR, KOOS JR, and the PROMIS PF in adult reconstruction patients. The PROMIS PF was consistently the most responsive instrument in this analysis.

CLINICAL SIGNIFICANCE

The HOOS JR, KOOS JR, and PROMIS PF are useful clinical instruments for assessing treatment change and may be selected as relevant to the specific needs and conditions of the adult joint reconstruction patient population. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1178-1184, 2018.

Establishing minimum clinically important difference values for the Patient-Reported Outcomes Measurement Information System Physical Function, hip disability and osteoarthritis outcome score for joint reconstruction, and knee injury and osteoarthritis outcome score for joint reconstruction in orthopaedics

AIM

To establish minimum clinically important difference (MCID) for measurements in an orthopaedic patient population with joint disorders.

METHODS

Adult patients aged 18 years and older seeking care for joint conditions at an orthopaedic clinic took the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS^® PF) computerized adaptive test (CAT), hip disability and osteoarthritis outcome score for joint reconstruction (HOOS JR), and the knee injury and osteoarthritis outcome score for joint reconstruction (KOOS JR) from February 2014 to April 2017. MCIDs were calculated using anchor-based and distribution-based methods. Patient reports of meaningful change in function since their first clinic encounter were used as an anchor.

RESULTS

There were 2226 patients who participated with a mean age of 61.16 (SD = 12.84) years, 41.6% male, and 89.7% Caucasian. Mean change ranged from 7.29 to 8.41 for the PROMIS^® PF CAT, from 14.81 to 19.68 for the HOOS JR, and from 14.51 to 18.85 for the KOOS JR. ROC cut-offs ranged from 1.97-8.18 for the PF CAT, 6.33-43.36 for the HOOS JR, and 2.21-8.16 for the KOOS JR. Distribution-based methods estimated MCID values ranging from 2.45 to 21.55 for the PROMIS^® PF CAT; from 3.90 to 43.61 for the HOOS JR, and from 3.98 to 40.67 for the KOOS JR. The median MCID value in the range was similar to the mean change score for each measure and was 7.9 for the PF CAT, 18.0 for the HOOS JR, and 15.1 for the KOOS JR.

CONCLUSION

This is the first comprehensive study providing a wide range of MCIDs for the PROMIS^® PF, HOOS JR, and KOOS JR in orthopaedic patients with joint ailments.

Quality of life after total knee arthroplasty

Total knee arthroplasty (TKA) results in a high degree of patient satisfaction, as it provides patients with considerable medium- and long-term benefits in terms of quality of life, pain relief and function. Nevertheless, the literature reports that up to 30% of patients are dissatisfied. This dissatisfaction is directly related to the patients' quality of life, which they deem insufficient. Their quality of life depends on many physical, behavioural, social and psychological factors that are not taken into account by functional outcome scores. After describing the principles of quality of life evaluation after TKA, we will assess the effects of patient-related factors, the surgical technique and postoperative program through an exhaustive review of the literature. Patient expectations after TKA will then be outlined, particularly return to work and return to sports.

Consistency in patient-reported outcome measures after total knee arthroplasty using patient-specific instrumentation: a 5-year follow-up of 200 consecutive cases

PURPOSE

The purpose of this study was to evaluate the 5-year follow-up results of the first 200 total knee arthroplasties (TKA) performed by one high-volume surgeon, using patient-specific information (PSI). To date, there has been no other research into the mid-term follow-up of TKA performed using PSI.

MATERIALS AND METHODS

A total of 184 consecutive patients (200 TKA) were evaluated. Outcome measures included implant survival rate, adverse events, and the following patient-reported outcome measures (PROMs); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), Pain Visual Analogue Score (VAS) and EuroQol-5D Score (EQ-5D).

RESULTS

Revision surgery was performed for late secondary prosthetic joint infection (n = 1, total revision), aseptic loosening (n = 1, tibial component revision), instability (n = 1, isolated polyethylene insert exchange), and polyethylene insert breakage (n = 1, isolated polyethylene insert exchange). Other adverse events were as follows: debridement, antibiotics and implant retention for early prosthetic joint infection (n = 1), surgical debridement for haemarthrosis (n = 1), superficial wound infection (n = 2), thromboembolic events (n = 2), compartment syndrome (n = 1), and nerve injury (n = 2). All median outcome scores for patient reported outcome measures at 5 years improved significantly compared with the preoperative values (p ≤ 0.05). Median outcome scores were not significantly different between 1- and 5-year moments of follow-up, except for a significant decrease of EQ-VAS (p ≤ 0.05) between these two follow-up moments.

CONCLUSION

PROMs are consistent for 5-year follow-up of TKA using PSI. After 5 years of follow-up, revision surgery for any reason occurred in four patients (2%).

LEVEL OF EVIDENCE

III.

Joint awareness in posttraumatic osteoarthritis of the knee: validation of the forgotten joint score in long term condition after tibial plateau fracture

Background

Evaluating patient-reported outcomes (PRO) in early osteoarthritis (OA) of the knee is difficult. Established measurement tools are focused on one of the two major patient groups in knee surgery: young, highly active patients, or older patients with advanced degenerative OA of the knee. Joint awareness in everyday life is a crucial criterion in measuring PRO. The purpose of this study was to validate a German version of the “Forgotten Joint Score” (FJS) in patients after surgical treatment of tibial plateau fractures.

Methods

In this prospective cohort study, clinical and radiological outcomes data were collected from patients after surgical treatment of tibial plateau fractures following a skiing accident. Functional outcome questionnaires were administered including the FJS, the Lysholm-Score, the Tegner-Activity Scale (TAS), the EuroQol-5D (EQ 5-D), and a subjective rating of change. The validation study was carried out according to the COSMIN checklist protocol. The KLS was used to measure the presence and severity of OA on knee radiographs, and correlation with the FJS was measured.

Results

Cronbach‘s alpha was .96 (95%-CI .92, .99) confirming good internal consistency. Test-retest reliability of the FJS was high with an ICC₍₆₇₎ = .91 (95%-CI .85,.95). Furthermore, no relevant floor or ceiling effects were observed. FJS significantly differed in patients with different OA degrees (p = .041). Symptomatic patients had significant lower FJS than asymptomatic patients (p < .001).

Conclusions

This is the first study validating a disease-specific PRO, the FJS, in long-term outcomes after joint fracture. We demonstrated good psychometric properties and a significant correlation between the FJS and the radiologic degree of OA in patients with a history of tibial plateau fracture.

Trial registration

Clinical Trial Registry University of Regensburg Z-2015-0872-2. Registered 01. October 2015.