Development of a scale to assess performance following primary total knee arthroplasty

"Anatomic patella design versus medialized dome design in the modern posterior stabilized (ATTUNE) total knee arthroplasty: a systematic review and meta-analysis"

BACKGROUND

Patellar component design in total knee arthroplasty (TKA) can influence patellofemoral kinematics and clinical outcomes. The medialized dome design (MDD) aligns the patella apex more medially, while the anatomic patella design (APD) aims to replicate the native patella's shape and tracking. Although biomechanical studies suggest potential benefits of APD, clinical evidence remains inconclusive.

METHODS

A systematic review and meta-analysis following PRISMA guidelines was conducted to compare the clinical outcomes of MDD and APD in a modern posterior-stabilized TKA (ATTUNE system). We searched PubMed, Scopus, Embase, and Web of Science on January 10, 2025, without language or date restrictions. Eligible studies included randomized controlled trials (RCTs) and comparative cohort designs evaluating patient-reported outcome measures (PROMs), revisions, complications, range of motion (ROM), and radiologic measures of patellar stability. Risk of bias was assessed using RoB-2 for RCTs and ROBINS-I for cohort studies. Pooled effect sizes were calculated using Hedges's g and random-effects modeling.

RESULTS

Seven studies, including three RCTs and four cohort studies, with a total of 1,069 patients and 1,113 knees (507 APD vs. 606 MDD), were included. The meta-analysis demonstrated no significant difference in PROMs (Hedges's g = 0.09; 95% CI [-0.04 to 0.22]; P = 0.17) or ROM (Hedges's g = 0.02; 95% CI [-0.21 to 0.26]; P = 0.83) between APD and MDD. While revision rates and complications were higher for APD, the differences were not statistically significant compared to MDD (14 vs 9). Radiographic measures showed inconsistencies and did not definitively favor either design.

CONCLUSIONS

Current evidence suggests that APD offers no clear clinical advantage over MDD in the ATTUNE posterior-stabilized TKA. Both designs yield broadly comparable PROMs and knee function outcomes. Larger RCTs with extended follow-up are warranted to clarify the safety of APD.

LEVEL OF EVIDENCE

III.

Patient involvement in the development of patient-reported outcome measures used following hip or knee arthroplasty: a scoping review

PURPOSE

Involving patients in developing patient-reported outcome measures (PROMs) is essential for accurately capturing their perspectives. However, understanding how patients were involved in developing PROMs used after hip or knee arthroplasty is limited. This scoping review aimed to evaluate whether patients were involved in the development of these PROMs and how they were involved.

METHODS

Two independent reviewers documented patient involvement in item development and comprehensibility testing for 50 PROMs used after hip or knee arthroplasty. Trends in patient involvement over time were analyzed using binary logistic regression.

RESULTS

There was no documentation of patient involvement in a collaborative role during the PROM development processes. Regarding the consultative role, of these 26 PROMs, they contributed to item development in 13 PROMs (26%) and comprehensibility testing in four PROMs (8%) and both item development and comprehensibility testing in nine PROMs (18%). Patients who underwent arthroplasty were involved in one or both phases in ten PROMs (20%), while patients with other lower extremity conditions were involved in 16 PROMs (32%). Patients who underwent arthroplasty contributed to both phases in five PROMs: Oxford Knee Score-Activity and Participation Questionnaire, Patient's Knee Implant Performance Questionnaire, Patient-Reported Outcomes Measurement Information System R-Plus-Osteoarthritis of the Knee, Oxford Arthroplasty Early Recovery Score and Oxford Arthroplasty Early Change Score. In addition, our analysis revealed no significant change in patient involvement in a consultative role during either item development or comprehensibility evaluation over time since 1982, when the first PROM included in this review was developed (p = 0.21).

CONCLUSIONS

Almost half of PROMs used after arthroplasty did not involve patients in their development, highlighting the need to address this gap in development of PROMs. There is also a need to analyze PROMs to ensure they accurately reflect the outcomes that matter to patients.

Understanding data visualization techniques in qualitative studies used to develop and validate patient-reported outcome measures: a targeted literature review

PURPOSE

Qualitative data that reflects patients' experiences are the foundation of any patient-reported outcome measure (PROM) development and validation study; however, there is limited understanding of the type of data visualization techniques that facilitate communication of this data. The goal of this targeted literature review was to investigate data visualization methods that have been used in published PROM development and validation literature to report qualitative results.

METHODS

A literature search in OVID via MEDLINE was conducted among the top 10 non-disease-specific journals publishing PROM qualitative development and validation studies. Studies that reported qualitative methods to develop/validate a PROM and included data visualization in the form of tables or figures were included. Article characteristics and data visualization types were extracted.

RESULTS

A total of 185 articles were included in data extraction. Most articles (n = 109, 59.1%) included figures (n = 172, average 2 relevant figures per article) in the form of hierarchy/flowcharts (n = 124, 72.1%) and bar charts (n = 29, 16.9%). Information reported in figures included depiction of conceptual frameworks (n = 112, 65.1%) and concept frequency (n = 40, 24.4%). Most articles (n = 152, 81.7%) included tables (n = 307, average 2 relevant tables per article). Information reported in tables included concept frequency (n = 133, 43.3%) and cognitive debriefing and revisions (n = 91, 29.6%).

CONCLUSION

Data visualization techniques used to report qualitative results in the identified PROM qualitative development and validation studies were heterogeneous, and many studies did not utilize any data visualization techniques. This study will inform the development of guidance for using data visualizations to report qualitative PROM research.

The validity and reliability of the Turkish version of the Patient's Knee Implant Performance (PKIP) questionnaire-preoperative and postoperative

The Patient's Knee Implant Performance (PKIP) Questionnaire is a short and easy-to-complete questionnaire developed to assess the performance of total knee arthroplasty (TKA) more comprehensively. The aim of this study was to investigate the validity and reliability of the Turkish version of the PIKP questionnaire before (PKIP PreOp) and after (PKIP PostOp) TKA. The study included 162 patients referred for TKA and 154 patients who had undergone the surgery at least 3 months prior. Cronbach alpha, intra-class correlation coefficient, and item-total correlation values were calculated to assess the reliability of the PIKP questionnaire. Validity was determined using exploratory and confirmatory factor analysis. To determine parallel scale validity, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), The Short Form-36 (SF-36) Quality of Life Scale performance score were used. The mean age of the participants was 66.39 ± 7.65 years. Cronbach alpha and intra-class correlation coefficient values of the PKIP were acceptable (0.723 and 0.985, respectively). The item-total correlation values of each item of the PKIP was also acceptable (lowest ranged from 0.335 to 0.621). Confirmatory and exploratory factor analysis revealed that the both PKIP PreOp and PKIP PostOp studies had sufficient fit. The PKIP PreOp and PKIP PostOp was moderately to strongly correlated with the Western Ontario and McMaster Universities Osteoarthritis Index and Short Form-36 score (P < .001). Patients undergoing TKA had a significantly higher PKIP PostOp score than PKIP PreOp score. The Turkish version of the PKIP is valid, reliable, and sensitive to assess in performance in patients undergoing TKA.

A multi-phase approach for developing a conceptual model and preliminary content for patient-reported outcome measurement in TKA patients: from a Chinese perspective

PURPOSE

Patient-reported outcome measures (PROMs) are being used more frequently in total knee arthroplasty (TKA). By utilizing high-quality scales, surgeons can achieve a more comprehensive and accurate evaluation of the effectiveness of TKA surgery. Currently, there is no widely accepted conceptual model for TKA PROMs. The objective of this study is to fill this gap by developing a conceptual model and preliminary content for a PROM that is specifically designed for TKA patients in mainland China.

METHODS

The study design consisted of three stages: (1) a targeted literature review followed by the formation of a conceptual model pool; (2) qualitative data collection involving experts and patients, leading to the development of the preliminary Chinese TKA PROM (CTP); and (3) review of the CTP by experts using the Delphi method, along with cognitive debriefing interviews with patients.

RESULTS

64 patients and 28 experts took part in this study. The conceptual model focused on six key concepts: pain, symptom, function, quality of life, expectation, and satisfaction. To match the model, the authors developed a total of 35 items.

CONCLUSION

A conceptual model and preliminary content for CTP was developed with substantial participation from patients and a multidisciplinary group of experts. The integration of patient and clinical perspectives ensured a comprehensive representation of all relevant disease experiences and the focus of clinical practice. With further refinement through psychometric testing, the CTP is positioned to provide a standardized, comprehensive measure for research specific to Chinese TKA patients.

The Forgotten Joint Score Is a Valid Outcome Measure for Total Ankle Arthroplasty: A Prospective Study

BACKGROUND

The success of total ankle arthroplasty (TAA) involves objective and subjective parameters such as joint motion and implant survival. Patient-reported outcome measures provide key context from the patient's perspective so that we can evaluate the results of these procedures. The Forgotten Joint Score (FJS) has demonstrated validity and reliability in other arthroplasties, but the existing evidence on the FJS in TAA is very limited.

QUESTION/PURPOSES

We aimed to assess the reliability, validity, responsiveness to change, and floor and ceiling effects, as well as to perform a gender analysis, of the FJS in patients who had undergone TAA.

METHODS

A prospective, observational study enrolled patients who underwent TAA at our institution between June 2021 and May 2023. The three-component TAA was performed through an anterior approach. A total of 120 patients (mean age 62 ± 10 years) participated, which was 83% (120 of 145) of those eligible, and 77% (92 of 120) of those patients underwent follow-up assessments at 12 ± 1 months after surgery. A cross-culturally adapted and validated version of the FJS in our language (Italian) was used. Additionally, three other commonly used patient-reported outcome measures for TAA were administered: the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, the Manchester-Oxford Foot Questionnaire (MOXFQ), and the VAS.

RESULTS

Reliability was demonstrated by excellent internal consistency (Cronbach α coefficient = 0.95) and excellent test-retest reliability (intraclass correlation coefficient = 0.99; standard error of measurement = 2.7). Robust validity was observed, in that the FJS had a strong correlation with the AOFAS ankle-hindfoot score, the MOXFQ, and the VAS (Pearson and Spearman values consistently above 0.7 or below -0.7). Responsiveness to change was observed between 6 and 12 months (Cohen d = 0.37). Low ceiling and floor effects at both 6 months (4% and 3% reached top and bottom scores, respectively) and 12 months (10% and 0% reached top and bottom scores, respectively) were demonstrated, below the recommended 15% interpretability threshold. No association between outcomes and patient gender was observed.

CONCLUSION

Test properties and validity of the FJS were strong in patients who underwent TAA. It seems suitable for clinical use, although future studies should seek to replicate or refute our findings in other patient populations.

LEVEL OF EVIDENCE

Level II, therapeutic study.

What's important for recovery after a total knee replacement? A systematic review of mixed methods studies

BACKGROUND

Understanding how patients perceive and prioritise various aspects of recovery following total knee replacement, including pain, function and return to activity, will help clinicians in pre-operative consultations by ensuring they effectively address patient concerns and managing their expectations.

AIMS

The aim of this study is to identify aspects of recovery that are important to people after a total knee replacement.

METHODS

Studies were identified from Medline, Embase, PsycInfo, Cochrane Library and Web of Science. This mixed methods review included all original study types (quantitative, qualitative, discrete choice experiments and mixed methods design). Reviews and non-peer-reviewed publications were excluded. Studies with participants (age ≥ 18 years) who had a primary TKR for osteoarthritis were included. Studies of people with unicompartmental knee, patella-femoral or revision knee replacement were excluded. Recovery attributes were extracted from individual papers and grouped into recovery themes.

RESULTS

A total of 23 studies with 8404 participants and 18 recovery themes were developed. The most frequently identified overarching theme was pain, followed by activities of daily living, mobility (walking), recreational activities, specific functional movements of the knee, use of walking aids, sexual activity and range of motion of the knee. Medical complications were an infrequently reported theme, however, was deemed to be high importance.

CONCLUSIONS

Reducing pain, returning of activities and daily living and mobility are the three most frequently reported recovery domains for people after TKR. Clinicians should be aware of recovery themes, to ensure they are explored sufficiently when consenting for a TKR. Future research should aim to determine the relative importance of these attributes compared to each other. Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021253699.

Randomized controlled trial comparing traditional versus enhanced-fixation designs of a novel cemented total knee arthroplasty tibial component

Aims

A novel enhanced cement fixation (EF) tibial implant with deeper cement pockets and a more roughened bonding surface was released to market for an existing total knee arthroplasty (TKA) system.This randomized controlled trial assessed fixation of the both the EF (ATTUNE S+) and standard (Std; ATTUNE S) using radiostereometric analysis.

Methods

Overall, 50 subjects were randomized (21 EF-TKA and 23 Std-TKA in the final analysis), and had follow-up visits at six weeks, and six, 12, and 24 months to assess migration of the tibial component. Low viscosity bone cement with tobramycin was used in a standardized fashion for all subjects. Patient-reported outcome measure data was captured at preoperative and all postoperative visits.

Results

The patient cohort mean age was 66 years (SD seven years), 59% were female, and the mean BMI was 32 kg/m2 (SD 6 kg/m2). Mean two-year subsidence of the EF-TKA was 0.056 mm (95% confidence interval (CI) 0.025 to 0.086) versus 0.006 mm (95% CI -0.029 to 0.040) for the Std-TKA, and the two-year maximum total point motion (MTPM) was 0.285 mm (95% upper confidence limit (UCL) ≤ 0.363) versus 0.346 mm (95% UCL ≤ 0.432), respectively, for a mean difference of -0.061 mm (95% CI -0.196 to 0.074). Inducible displacement also did not differ between groups. The MTPMs between 12 and 24 months for each group was below the published threshold of 0.2 mm for predicting early aseptic loosening (p < 0.001 and p = 0.001, respectively).

Conclusion

Both the enhanced fixation and the standard tibial implant design showed fixation with a predicted low risk of long-term aseptic loosening.

EQ-5D-3L and quality of life in total knee arthroplasty (TKA) patients: beyond the index scores

Background

Many patient reported outcome measures (PROMs) generate single number index scores that summarise responses to different questions within a questionnaire. Although these are valuable as unambiguous indicators of ill-health and changes in health, further information can be gained from examining the questionnaire responses themselves. This has additional importance since the patients’ reports are those responses and not the index scores. This paper reanalyses data from two prospective multicentre clinical studies assessing patients’ quality of life before and after total knee arthroplasty (TKA) using the EQ-5D-3L. Patients who completed EQ-5D-3L questionnaires at 3 time periods were included from 4 countries (USA, UK, Australia, New Zealand) operated on by the same surgeons using two different knee replacement systems. Descriptive analyses included levels within EQ-5D dimensions and profiles (combinations of dimensions and levels) at baseline and follow-up, including changes over time and differences between implants. Regression analysis quantified the relationship between the profiles and the EQ VAS.

Results

Problems with mobility, usual activities and pain & discomfort, in that order, were most frequent for pre-operative patients. There were large improvements in every dimension after surgery, but the time that this was observed differed: for mobility, self-care and anxiety & depression, most of the improvement occurred during the first 10 months; for usual activities and pain & discomfort, over 11–22 months. Analysing profiles, 85% of patients experienced an unequivocal improvement, 5.9% had no change, 3.5% worsened and 5.5% a mixed change at 11–22 months follow-up. Anxiety & depression had the greatest impact on EQ VAS scores; while mobility and usual activities were also important; usual activities was particularly important post-surgery.

Conclusions

The value of analysing patients’ responses to PROMs questionnaires without using summary scores was confirmed. The results add further detail to existing knowledge about the health problems that TKA patients experience before surgery, improvements after surgery, residual problems that some have, and the time at which improvements are experienced. This was a small study, but its methods may be easily replicated in other studies that use the EQ-5D-3L. It may also be possible to adapt them for other PROMs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-022-00497-0.

Preoperative morbidity and joint awareness while awaiting hip arthroscopy for femoroacetabular impingement

Purpose

The Forgotten Joint Score (FJS-12) is a valid tool in the evaluation of patients undergoing hip arthroscopy, assessing the unique concept of joint awareness in the setting of a patient’s hip pathology. The preoperative burden on patients’ mental wellbeing of impaired joint function or symptoms is well established. The purpose of this study was to determine patients’ awareness of their hip joint whilst awaiting hip arthroscopy for femoroacetabular impingement, to explore any association between joint awareness and mental health status, and to determine whether this relates to time spent waiting for arthroscopy preoperatively.

Methods

A prospective database of patients undergoing hip arthroscopy between January 2018 and November 2020 was analysed. All patients with a diagnosis of femoroacetabular impingement (FAI) undergoing arthroscopic treatment were included. Questionnaires included the FJS-12, twelve item international hip outcome tool (iHOT-12), EuroQol 5D-5L (EQ-5D-5L) and the Tegner activity score. Pearson’s correlation coefficient was used to assess relationships between continuous variables.

Results

Preoperative functional outcomes were completed by 81 patients (97.5%) prior to undergoing hip arthroscopy. Median preoperative FJS-12 score was 16.67 (IQR 8.33 – 29.68). Forty-four patients reported any level of anxiety/depression preoperatively (54.3%). Preoperative FJS-12 showed a significant negative correlation with worsening mental health status (r = − 0.359, p <  0.001), and a significant positive correlation with EQ-5D-5L (r = 0.445, p <  0.001). The duration of symptoms or time on the waiting list did not correlate with increased joint awareness or worsened mental health.

Conclusion

Joint awareness is high when awaiting hip arthroscopy for FAI. Increasing levels of joint awareness correlate with poorer mental health status and poorer quality of life measures, however these parameters do not seem to be associated with increased duration of symptoms prior to surgery or time on the waiting list for surgery.

Comparison of Existing and New Total Knee Arthroplasty Implant Systems From the Same Manufacturer: A Prospective, Multicenter Study

This study evaluated total knee arthroplasty (TKA) outcomes for an Existing-TKA versus New-TKA from the same manufacturer.

Early outcomes and predictors of patient satisfaction after TKA: a prospective study of 200 cases with a contemporary cemented rotating platform implant design

Purpose

The purpose of the study was to identify the earliest time point where subjects realized the greatest clinical improvement after TKA, and the time when post-operative scores became superior to pre-operative scores. Post-hoc exploratory analyses were conducted to investigate predictors of early post-operative outcomes and patient satisfaction.

Methods

Six investigators across 4 sites in the Netherlands prospectively implanted 200 subjects with a contemporary cemented rotating platform device. Patient Reported Outcome Measurements (PROMs) KOOS-PS, PKIP, and EQ-5D were collected pre-operatively and post-operatively through 2-years. PROMs change from pre-operative baseline were summarized, along with radiographic outcomes and adverse events (AEs). Pre-operative patient characteristics were explored for correlation with patient outcomes, and patient satisfaction for correlation with KOOS-PS.

Results

Follow-up compliance was 99% at 6-months, and 95.5% at 2-years. The percentage with higher KOOS-PS compared to baseline was 81.3% at 6-months. KOOS-PS, PKIP, and PKIP subscore means were all better at 6-weeks versus baseline. Gender, BMI, hypertension, and pre-operative KOOS-PS were weakly correlated with 6-week KOOS-PS (multivariate R-squared = 14.1%), but only pre-operative KOOS-PS demonstrated correlation with post-operative KOOS-PS at 6-months or later (R-squared < 5% at 6-months and 2 years). Satisfaction was moderately correlated with concurrent KOOS-PS at each post-operative time point, with (R-squared = 35.3% at 6-months, and 37.5% at 2 years).

Conclusion

The greatest mean clinical improvement occurred within the first 6-weeks. Although some pre-operative factors were correlated with higher early post-operative KOOS-PS outcomes, these advantages disappeared by 6-months aside from weak correlation with pre-operative KOOS-PS. Post-operative KOOS-PS was moderately correlated with concurrent post-operative satisfaction. These results may be used for pre-operative counseling and management of patient’s postoperative expectations.

Trial registration

Clinicaltrials.gov, NCT02339610. Registered 15 January 2015.

Patient-reported outcome measures used in patients undergoing total knee arthroplasty

Patient-reported outcome measures (PROMs) are being used increasingly in total knee arthroplasty (TKA). We conducted a systematic review aimed at identifying psychometrically sound PROMs by appraising their measurement properties. Studies concerning the development and/or evaluation of the measurement properties of PROMs used in a TKA population were systematically retrieved via PubMed, Web of Science, Embase, and Scopus. Ratings for methodological quality and measurement properties were conducted according to updated COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology. Of the 155 articles on 34 instruments included, nine PROMs met the minimum requirements for psychometric validation and can be recommended to use as measures of TKA outcome: Oxford Knee Score (OKS); OKS-Activity and Participation Questionnaire (OKS-APQ); 12-item short form Knee Injury and Osteoarthritis Outcome (KOOS-12); KOOS Physical function Short form (KOOS-PS); Western Ontario and McMaster Universities Arthritis Index-Total Knee Replacement function short form (WOMAC-TKR); Lower Extremity Functional Scale (LEFS); Forgotten Joint Score (FJS); Patient's Knee Implant Performance (PKIP); and University of California Los Angeles (UCLA) activity score. The pain and function subscales in WOMAC, as well as the pain, function, and quality of life subscales in KOOS, were validated psychometrically as standalone subscales instead of as whole instruments. However, none of the included PROMs have been validated for all measurement properties. Thus, further studies are still warranted to evaluate those PROMs. Use of the other 25 scales and subscales should be tempered until further studies validate their measurement properties. Cite this article: Bone Joint Res 2021;10(3):203-217.

Health costs and efficiencies of patient-specific and single-use instrumentation in total knee arthroplasty: a randomised controlled trial

Aim

To investigate whether patient-specific instrumentation (PSI) and single-use instrumentation (SUI) improve operating room efficiency in terms of time and cost to the healthcare provider over conventional/reusable instrumentation (CVR) when performing total knee arthroplasty (TKA).

Patients and methods

Patients requiring TKA were randomised into one of four surgical groups: CVR, CVS (conventional/SUI), PSR (PSI/reusable) and PSS (PSI/SUI). All surgical procedures were video recorded to determine specific surgical time intervals. Other variables reported included the number of instrument trays used, missing equipment, direct instrument costs and the weight of the instruments the staff had to handle. Oxford Knee Score (OKS), estimated blood loss and lengths of hospital stay were also recorded as markers of patient experience.

Results

PSR was significantly quicker in all the recorded time intervals, used less trays, experienced less missing equipment and resulted in lower blood loss and shorter hospital stays. SUI reported significantly slower operating room times and resulted in higher blood loss, but SUI was 88% lighter and 20% cheaper on average when compared with their reusable counterparts. Despite the economic advantages of PSI and SUI, the patients who reported greatest improvements in OKS were those allocated to the CVR group, but no clinically meaningful difference in OKS was found at any time point.

Conclusions

PSI and SUI for TKA have the potential of reducing operating room times over conventional, reusable sets. This reduction will benefit theatre personnel ergonomically, while presenting the healthcare provider with potential cost-saving benefits in terms of reduced sterilisation costs and surgical times.

Influence of Component Geometry on Patellar Mechanics in Posterior-Stabilized Rotating Platform Total Knee Arthroplasty

BACKGROUND

Patellofemoral complications may cause pain and discomfort, sometimes leading to revision surgery for total knee arthroplasty patients, and patellar implant design has an impact on function of the reconstructed knee. The purpose of this in vivo biomechanics study was to understand the kinematic, functional, strength, and patient-reported outcome data of patients with anatomic and dome patellar implants.

METHODS

Satisfactory age-matched, gender-matched, and body mass index-matched patients who underwent rotating-platform total knee arthroplasty from one joint replacement system with either dome (n = 16) or anatomic (n = 16) patellar components were tested in a human motion laboratory using high-speed stereoradiography during an unweighted seated knee extension and a weight-bearing lunge activity. Patellar kinematics, range of motion, strength, and patient-reported outcomes were compared between subjects with anatomic or dome component geometry.

RESULTS

Both groups of patients achieved similar functional knee range of motion and reported similar outcomes and satisfaction. On average, patients with the anatomic component had 36% greater extensor strength compared with dome subjects. Patients with anatomic patellar components demonstrated significantly greater flexion of the patella relative to the femur and lower external rotation during the weighted lunge activity.

CONCLUSIONS

Relative to the modified dome geometry, patients with anatomic patellar geometry achieved greater patellar flexion which may better replicate normal patellar motion. Patients with anatomic implants may regain more extensor strength compared to patients with dome implants due to geometric differences in the patellar component designs.

The assessment of the stability of the tibial component of a novel knee arthroplasty system using radiostereometric analysis

Aims

The introduction of a novel design of total knee arthroplasty (TKA) must achieve outcomes at least as good as existing designs. A novel design of TKA with a reducing radius of the femoral component and a modified cam-post articulation has been released and requires assessment of the fixation to bone. Radiostereometric analysis (RSA) of the components within the first two postoperative years has been shown to be predictive of medium- to long-term fixation. The aim of this study was to assess the stability of the tibial component of this system during this period of time using RSA.

Patients and Methods

A cohort of 30 patients underwent primary, cemented TKA using the novel posterior stabilized fixed-bearing (ATTUNE) design. There was an even distribution of men and women (15:15). The mean age of the patients was 64 years (sd 8) at the time of surgery; their mean body mass index (BMI) was 35.4 kg/m 2 (sd 7.9). RSA was used to assess the stability of the tibial component at 6, 12, and 24 months compared with a six-week baseline examination. Patient-reported outcome measures were also assessed.

Results

The mean maximum total point motion (MTPM) of the tibial component between 12 and 24 months postoperatively was 0.08 mm (sd 0.08), which is well below the published threshold of 0.2 mm (p < 0.001). Patient-reported outcome measures consistently improved.

Conclusion

The tibial component of this novel design of TKA showed stability between assessment 12 and 24 months postoperatively, suggesting an acceptably low risk of medium- to long-term failure due to aseptic loosening.

Psychometric Evaluation of the Patient's Knee Implant Performance Questionnaire

OBJECTIVES

To evaluate the psychometric properties of Patient's Knee Implant Performance Questionnaire (PKIP), a new patient-reported measure of knee implant functional performance assessing patient experiences before and after primary total knee arthroplasty (TKA).

METHODS

The psychometric analysis sample (n = 761) was based on an ongoing, multisite, prospective, noncomparative, longitudinal study of patients undergoing TKA. The PKIP was completed at three study visits: presurgery (visit 1), less than 1 year (visit 3, days 1-303), and minimum 1 year (visit 4, days 304-668). Visit 2 was an operative visit. Supporting outcome measures were collected at each study visit. The PKIP structure and its psychometric properties were assessed as part of a secondary data analysis using an interim data cut before the end of the clinical trial.

RESULTS

The PKIP includes four subscales (confidence, stability, activity modification, and satisfaction) and an overall PKIP score. The overall PKIP score met internal consistency (visit 4 = 0.79) and test-retest reliability (intraclass correlation coefficient = 0.77) standards. Correlations between the PKIP and other measures (e.g., the American Knee Society score and the Knee Injury and Osteoarthritis Outcome Score) provided evidence of construct validity. The PKIP was capable of discriminating between groups of patients with better or worse knee function. The effect size for the overall PKIP score was 2.96 from baseline to visit 4, indicating that the PKIP was highly responsive.

CONCLUSIONS

The reliability, validity, and responsiveness of the PKIP support its use among patients undergoing TKA.

Quadriceps weakness preferentially predicts detrimental gait compensations among common impairments after total knee arthroplasty

Patients with total knee arthroplasty (TKA) have large deficits in physical performance in comparison to their healthy age-matched peers. Limb asymmetry stemming from less relative load borne by the surgical limb during daily mobility is associated with diminished performance and worsens with greater mobility demands. How common targets of postoperative care, such as muscle weakness, lower limb extension power, residual knee pain, and poor balance confidence can influence asymmetrical limb loading remains unclear. Forty-six patients with unilateral TKA underwent testing of impairments and motion analysis during 10° decline walking at 3 and 6 months postoperatively. At 3 months, only quadriceps femoris strength asymmetry was found to be significantly related to both total support moment (M_T ) (β = 0.431; p < 0.001) and knee extensor moment (M_K ) (β = 0.493; p < 0.001) asymmetry. Again at 6 months, only quadriceps strength asymmetry was related to M_T (β = 0.432; p < 0.001) and M_K (β = 0.534; p < 0.001) asymmetry. Quadriceps strength significantly improved over time in both limbs, however, deficits between limbs remained. Persistent quadriceps weakness is a key factor associated with walking compensation patterns that are limiting the capacity for greater physical performance of patients with TKA. The pronounced asymmetry in limb and knee loading at 3 months remains unchanged until at least 6 months after surgery, and its association with quadriceps strength asymmetry does not substantially change over time. While other factors may also prompt gait compensations, emphasis on improved quadriceps strength should be a focus of efforts to resolve gait compensations and enhance physical performance outcomes. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2355-2363, 2018.

Learning curve with a new primary total knee arthroplasty implant: a multicenter perspective with more than 2000 patients

Background

This study provides an example for evaluating learning curve when introducing a new knee system.

Methods

Thirty-five investigators across 22 sites prospectively implanted 843 subjects with currently available products (group A). Seventy-seven investigators across 48 sites prospectively implanted 2330 subjects with the ATTUNE Knee System; in which the first 10 subjects for each surgeon were the learning curve cases (group B, N = 611), and the later subjects were designated as group C (N = 1719). Surgical time, rates of intraoperative and early postoperative complications, and patient-reported outcome measures (PROMs) at a minimum of 1 year were compared.

Results

Mean (standard deviation) surgical time was 72.0 (21.6) minutes for group A, 83.0 (24.2) for group B, and 72.1 (24.1) for group C (P < .001 for group B vs group C; P = .955 for group C vs group A). Intraoperative, early (<90 day) complication rates, and PROMs were similar for all groups.

Conclusions

The new knee system learning curve was characterized by a slightly longer surgical time with no negative impact on complications or PROMs.

Level of Evidence

III.

Critical inhaler errors in asthma and COPD: a systematic review of impact on health outcomes

BACKGROUND

Inhaled drug delivery is the cornerstone treatment for asthma and chronic obstructive pulmonary disease (COPD). However, use of inhaler devices can be challenging, potentially leading to critical errors in handling that can significantly reduce drug delivery to the lungs and effectiveness of treatment.

METHODS

A systematic review was conducted to define 'critical' errors and their impact on health outcomes and resource use between 2004 and 2016, using key search terms for inhaler errors in asthma and COPD (Search-1) and associated health-economic and patient burden (Search-2).

RESULTS

Search-1 identified 62 manuscripts, 47 abstracts, and 5 conference proceedings (n = 114 total). Search-2 identified 9 studies. We observed 299 descriptions of critical error. Age, education status, previous inhaler instruction, comorbidities and socioeconomic status were associated with worse handling error frequency. A significant association was found between inhaler errors and poor disease outcomes (exacerbations), and greater health-economic burden.

CONCLUSIONS

We have shown wide variations in how critical errors are defined, and the evidence shows an important association between inhaler errors and worsened health outcomes. Given the negative impact diminished disease outcomes impose on resource use, our findings highlight the importance of achieving optimal inhaler technique, and a need for a consensus on defining critical and non-critical errors.

What makes patients aware of their artificial knee joint?

Background

Joint awareness was recently introduced as a new concept for outcome assessment after total knee arthroplasty (TKA). Findings from qualitative and psychometric studies suggest that joint awareness is a distinct concept especially relevant to patients with good surgical outcome and patients at late follow-up time points. The aim of this study was to improve the understanding of the concept of joint awareness by identifying situations in which patients are aware of their artificial knee joint and to investigate what bodily sensations and psychological factors raise a patient’s awareness of her/his knee. In addition, we evaluated the relative importance of patient-reported outcome parameters that are commonly assessed in orthopaedics.

Methods

Qualitative interviews were conducted with patients being at least 12 months after TKA. The interviews focused on when, where and for what reasons patients were aware of their artificial knee joint. To evaluate the relative importance of ‘joint awareness’ after TKA among nine commonly assessed outcome parameters (e.g. pain or stiffness), we collected importance ratings (‘0’ indicating no importance at all and ‘10’ indicating high importance).

Results

We conducted interviews with 40 TKA patients (mean age 69.0 years; 65.0% female). Joint awareness was found to be frequently triggered by kneeling on the floor (30%), climbing stairs (25%), and starting up after resting (25%). Patients reported joint awareness to be related to activities of daily living (68%), specific movements (60%), or meteoropathy (18%). Sensations causing joint awareness included pain (45%) or stiffness (15%). Psychological factors raising a patient’s awareness of his/her knee comprised for example feelings of insecurity (15%), and fears related to revision surgeries, inflammations or recurring pain (8%). Patients’ importance ratings of outcome parameters were generally high and did not allow differentiating clearly among them.

Conclusions

We have identified a wide range of situations, activities, movements and psychological factors contributing to patients’ awareness of their artificial knee joints. This improves the understanding of the concept of joint awareness and of a patient’s perception of his/her artificial knee joint. The diversity of sensations and factors raising patient’s awareness of their joint encourages taking a broader perspective on outcome after TKA.

A Systematic Review of Measurement Properties of Patient-Reported Outcome Measures Used in Patients Undergoing Total Knee Arthroplasty

BACKGROUND

While clinical research on total knee arthroplasty (TKA) outcomes is prevalent in the literature, studies often have poor methodological and reporting quality. A high-quality patient-reported outcome instrument is reliable, valid, and responsive. Many studies evaluate these properties, but none have done so with a systematic and accepted method. The objectives of this study were to identify patient-reported outcome measures (PROMs) for TKA, and to critically appraise, compare, and summarize their psychometric properties using accepted methods.

METHODS

MEDLINE, EMBASE, SCOPUS, Web of Science, PsycINFO, and SPORTDiscus were systematically searched for articles with the following inclusion criteria: publication before December 2014, English language, non-generic PRO, and evaluation in the TKA population. Methodological quality and evidence of psychometric properties were assessed with the COnsensus-based standards for the selection of health Status Measurement INstruments (COSMIN) checklist and criteria for psychometric evidence proposed by the COSMIN group and Terwee et al.

RESULTS

One-hundred fifteen studies on 32 PROMs were included in this review. Only the Work, Osteoarthritis or joint-Replacement Questionnaire, the Oxford Knee Score, and the Western Ontario and McMaster Universities Arthritis Index had 4 or more properties with positive evidence.

CONCLUSION

Most TKA PROMs have limited evidence for their psychometric properties. Although not all the properties were studied, the Work, Osteoarthritis or joint-Replacement Questionnaire, with the highest overall ratings, could be a useful PROM for evaluating patients undergoing TKA. The methods and reporting of this literature can improve by following accepted guidelines.

Validation of the English language Forgotten Joint Score-12 as an outcome measure for total hip and knee arthroplasty in a British population

Aims

To validate the English language Forgotten Joint Score-12 (FJS-12) as a tool to evaluate the outcome of hip and knee arthroplasty in a United Kingdom population.

Patients and Methods

All patients undergoing surgery between January and August 2014 were eligible for inclusion. Prospective data were collected from 205 patients undergoing total hip arthroplasty (THA) and 231 patients undergoing total knee arthroplasty (TKA). Outcomes were assessed with the FJS-12 and the Oxford Hip and Knee Scores (OHS, OKS) pre-operatively, then at six and 12 months post-operatively. Internal consistency, convergent validity, effect size, relative validity and ceiling effects were determined.

Results

Data for the TKA and THA patients showed high internal consistency for the FJS-12 (Cronbach α = 0.97 in TKAs, 0.98 in THAs). Convergent validity with the Oxford Scores was high (r = 0.85 in TKAs, r = 0.79 for THAs). From six to 12 months, the change was higher for the FJS-12 than for the OHS in THA patients (effect size d = 0.21 versus -0.03). Ceiling effects at one-year follow-up were low for the FJS-12 with just 3.9% (TKA) and 8.8% (THA) of patients achieving the best possible score.

Conclusion

The FJS-12 has strong measurement properties in terms of validity, internal consistency and sensitivity to change in TKA and THA patients. Low ceiling effects and good relative validity allow the monitoring of longer term outcomes, particularly in well-performing groups after total joint arthroplasty. Cite this article: Bone Joint J 2017;99-B:218–24.