Translation and validation of the 12-item Oxford knee score for use in Finland

Cross-Culturally Adapted Versions of Patient Reported Outcome Measures for the Lower Extremity

Background

A large number of patient reported outcome measures (PROMs) have been developed in the English language for various lower extremity orthopaedic pathologies. Twenty different PROMs were recommended for 15 specific musculoskeletal lower extremity pathologies or surgeries. However, the availability of cross-culturally adapted versions of these recommended PROMs is unknown.

Purpose

The purpose of this study was to identify the cross-culturally adapted versions of recommended PROMs for individuals experiencing orthopedic lower extremity pathologies or undergoing surgeries, and to identify the psychometric evidence that supports their utilization.

Study design

Literature Review.

Methods

PubMed, Embase, Medline, Cochrane, CINAHL, SPORTDisucs and Scopus were searched for cross-culturally adapted translated studies through May 2022. The search strategy included the names of the 20 recommended PROMs from previous umbrella review along with the following terms: reliability, validity, responsiveness, psychometric properties and cross-cultural adaptation. Studies that presented a non-English language version of the PROM with evidence in at least one psychometric property to support its use were included. Two authors independently evaluated the studies for inclusion and independently extracted data.

Results

Nineteen PROMS had cross-culturally adapted and translated language versions. The KOOS, WOMAC, ACL-RSL, FAAM, ATRS, HOOS, OHS, MOXFQ and OKS were available in over 10 different language versions. Turkish, Dutch, German, Chinese and French were the most common languages, with each language having more than 10 PROMs with psychometric properties supporting their use. The WOMAC and KOOS were both available in 10 languages and had all three psychometric properties of reliability, validity, and responsiveness supporting their use.

Conclusion

Nineteen of the 20 recommended instruments were available in multiple languages. The PROM most frequently cross-culturally adapted and translated were the KOOS and WOMAC. PROMs were most frequently cross-culturally adapted and translated into Turkish. International researchers and clinicians may use this information to more consistently implement PROMs with the most appropriate psychometric evidence available to support their use.

Level of evidence

3a.

Effects of a home-based, exergaming intervention on physical function and pain after total knee replacement in older adults: a randomised controlled trial

Objectives

To investigate the effects of 4 months of customised, home-based exergaming on physical function and pain after total knee replacement (TKR) compared with standard exercise protocol.

Methods

In this non-blinded randomised controlled trial, 52 individuals aged 60-75 years undergoing TKR were randomised into an exergaming (intervention group, IG) or a standard exercising group (control group, CG). Primary outcomes were physical function and pain measured before and after (2 months and 4 months) surgery using the Oxford Knee Score (OKS) and Timed Up and Go (TUG) test. Secondary outcomes included measures of the Visual Analogue Scale, 10m walking, short physical performance battery, isometric knee extension and flexion force, knee range of movement and satisfaction with the operated knee.

Results

Improvement in mobility measured by TUG was greater in the IG (n=21) at 2 (p=0.019) and 4 months (p=0.040) than in the CG (n=25). The TUG improved in the IG by -1.9 s (95% CI, -2.9 to -1.0), while it changed by -0.6 s (95% CI -1.4 to 0.3) in the CG. There were no differences between the groups in the OKS or secondary outcomes over 4 months. 100% of patients in the IG and 74% in the CG were satisfied with the operated knee.

Conclusion

In patients who have undergone TKR, training at home with customised exergames was more effective in mobility and early satisfaction and as effective as standard exercise in pain and other physical functions. In both groups, knee-related function and pain improvement can be considered clinically meaningful.

Trial registration number

NCT03717727.

The Therapy-Related Symptom Checklist for Children as a Method for Monitoring Symptoms in Chinese Children With Cancer: Linguistic Validation and Cross-Cultural Adaptation

BACKGROUND

Children with cancer commonly experience severe symptoms. These may be managed by routine monitoring of their occurrence andseverity using a validated tool.

AIM

This study aimed to translate and culturally validate a simplified Chinese version of the Therapy-Related Symptom Checklist for Children (TRSC-C).

DESIGN

Qualitative method.

PARTICIPANTS AND SETTING

We recruited children with cancer from a pediatric department of a tertiary hospital in Guangzhou, China.

METHODS

We used forward and backward translation by bilingual translators and standardized cognitive interviewing for linguistic validation and to check cross-cultural adaptation. A panel of experts assessed content validity.

RESULTS

Agreement was reached on cultural applicability, suitability for intended purpose, and clarification of the pre-test version. The content validity was good (indices ranged from 0.80-0.90). Fifteen Chinese children with cancer (aged 8-18 years) were included in cognitive interviews. The cognitive debriefing showed that the instrument was easy to understand and appropriate for monitoring symptoms in children with cancer. Some words were adjusted following participants' comments.

CONCLUSIONS

The simplified Chinese version of the TRSC-C was semantically and conceptually equivalent to the original version. Children between 8-18 years old can use this instrument to report symptoms and share their experiences about their disease and treatment.

Reliability and validity of commonly used patient-reported outcome measures (PROMs) after medial unicompartmental knee arthroplasty

INTRODUCTION

Many patient-reported outcome measures (PROMs) have been utilized to assess outcomes after unicompartmental knee arthroplasty (UKA). However, most are not specifically designed for UKA and the measurement properties of these PROMs have never been elucidated in the setting of UKA. This study aimed to evaluate the reliability and validity of commonly used PROMs after UKA, which includes the Oxford knee score (OKS), Knee Society Score (KSS)-function score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee Injury and Osteoarthritis Outcome Score (KOOS).

HYPOTHESIS

The four commonly used PROMs after UKA are of good reliability and validity, but with different floor/ceiling effect.

MATERIAL AND METHODS

Prospectively collected postoperative follow-up PROMs scores of patients after medial UKA cases for osteoarthritis between May 2015 and June 2018 were retrospectively analyzed. All of the PROMs were finished on the same electronic questionnaires. Reliability (internal consistency, test-retest reliability, measurement error), construct validity and floor/ceiling effects were assessed.

RESULTS

The whole cohort was composed of 207 cases, with a median age of 62.0 years and a male ratio of 59/207 (28.50%). Internal consistency was high in the OKS, weak in the KSS-function score and with redundancy in the WOMAC and KOOS scores (Cronbach alpha=0.915, 0.610, 0.953, 0.961, respectively). Each of the four PROMs had a high test-retest reliability (all intraclass correlation coefficient (ICC) >0.97). Convergent validity of the four PROMs with the physical component score of the 12-Item Short Form Health Survey (SF-12 PCS) were proven (all r>0.5; p<0.001). While no ceiling effect occurred in the OKS, one was detected in the KSS-function score with 19.81% of patients achieving the best possible score, as well as in the WOMAC sub-score for pain (54.11%) and stiffness (50.72%), in addition to the KOOS sub-score for symptoms (27.54%) and pain (38.16%).

DISCUSSION

The four commonly used PROMs after UKA showed good test-retest reliability and construct validity. The OKS is more recommended for its better performance in internal consistency and ceiling effect than the KSS-function score, the WOMAC and KOOS scores.

LEVEL OF EVIDENCE

III; Diagnostic study.

Effectiveness of Gamification in Knee Replacement Rehabilitation: Protocol for a Randomized Controlled Trial With a Qualitative Approach

BACKGROUND

Exergames can provide encouraging exercise options. Currently, there is limited evidence regarding home-based exergaming in the postoperative phase of total knee replacement (TKR).

OBJECTIVE

This study aimed to investigate the effects of a 4-month postoperative home-based exergame intervention with an 8-month follow-up on physical function and symptoms among older persons undergoing TKR compared with home exercise using a standard protocol. In addition, a concurrent embedded design of a mixed methods study was used by including a qualitative component within a quantitative study of exergame effects.

METHODS

This was a dual-center, nonblinded, two-arm, parallel group randomized controlled trial with an embedded qualitative approach. This study aimed to recruit 100 patients who underwent their first unilateral TKR (aged 60-75 years). Participants were randomized to the exergame or standard home exercise arms. Participants followed a custom-made exergame program independently at their homes daily for 4 months. The primary outcomes at 4 months were function and pain related to the knee using the Oxford Knee Score questionnaire and mobility using the Timed Up and Go test. Other outcomes, in addition to physical function, symptoms, and disability, were game user experience, exercise adherence, physical activity, and satisfaction with the operated knee. Assessments were performed at the preoperative baseline and at 2, 4, and 12 months postoperatively. Exergame adherence was followed from game computers and using a structured diary. Self-reported standard exercise was followed for 4 months of intervention and physical activity was followed for 12 months using a structured diary. Qualitative data on patients' perspectives on rehabilitation and exergames were collected through laddering interviews at 4 and 12 months.

RESULTS

This study was funded in 2018. Data collection began in 2019 and was completed in January 2022. The COVID-19 pandemic caused an unavoidable situation in the study for recruitment, data collection, and statistical analysis. As of November 2020, a total of 52 participants had been enrolled in the study. Primary results are expected to be published by the end of 2022.

CONCLUSIONS

Our study provides new knowledge on the effects of postoperative exergame intervention among older patients with TKR. In addition, this study provides a new understanding of gamified postoperative rehabilitation, home exercise adherence, physical function, and physical activity among older adults undergoing TKR.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03717727; https://clinicaltrials.gov/ct2/show/NCT03717727.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/38434.

Validation and Cross-Cultural Adaptation of the Hindi Version of the Oxford Knee Score in Patients With Knee Osteoarthritis

Introduction: Cases of knee osteoarthritis are on the rise in India with an increasingly ageing population. A large number among them shall undergo total knee replacement, so there is a requirement for validated patient-reported outcome measures in the Hindi language. Oxford Knee Score (OKS) is one of the most commonly used patient-reported outcome measure scoring systems. The current study was designed to test and validate cross-cultural adaptation and translate the Hindi version of the Oxford Knee Score (OKS-H). 

Material and Methods: The OKS-H was formulated as per recommendations for cross-cultural adaptation and translation. The OKS was tested on 162 patients with knee osteoarthritis who underwent a total knee replacement. Reliability of the OKS-H was tested using the intraclass correlation coefficient (ICC) and internal consistency was assessed using Cronbach’s alpha. The construct validity was assessed using OKS-H, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 36-Item Short Form Survey (SF-36) questionnaire. 

Results: The translation was performed with no major difficulty. The OKS was completed by 158 (97.5%) and 157 (96.9%) patients at test and retest, respectively, after one week. With an ICC of 0.87, OKS had shown good reliability. The construct validity obtained against the WOMAC and SF-36 scores was strong (ICC between 0.49 to 0.86).

Conclusion: The translated OKS-H is a reliable and valid instrument for patient-reported outcome measures in cases of knee osteoarthritis opting for total knee arthroplasty.

Translation, cross-cultural adaptation, reliability and construct validity of the Dutch Oxford Knee Score - Activity and Participation Questionnaire

Background

Patients undergoing total knee arthroplasty (TKA) tend to be younger and tend to receive TKA at an earlier stage compared to 20 years ago. The Oxford Knee Score – Activity and Participation (OKS-APQ) questionnaire evaluates higher levels of activity and participation, reflecting activity patterns of younger or more active people. The purpose of this study was to translate the OKS-APQ questionnaire into Dutch, and to evaluate its measurement properties in pre- and postoperative TKA patients.

Methods

The OKS-APQ was translated and adapted according to the forward–backward translation multi step approach and tested for clinimetric quality. Floor and ceiling effects, structural validity, construct validity, internal consistency and test–retest reliability were evaluated using COSMIN quality criteria. The OKS-APQ, the Oxford Knee Score (OKS), the Short Form-36 (SF-36), a Visual Analogue Scale (VAS) for pain and the Forgotten Joint Score (FJS) were assessed in 131 patients (72 preoperative and 59 postoperative TKA patients), and the OKS-APQ was administered twice in 50 patients (12 preoperative and 38 postoperative TKA patients), after an interval of minimal 2 weeks.

Results

Floor effects were observed in preoperative patients. Confirmatory factor analyses (CFA) indicated a good fit of a 1-factor model by the following indices: (Comparative Fit Index (CFI): 0.97, Tucker-Lewis Index (TLI): 0.96 and Standardized Root Mean Square Residual (SRMR): 0.03). Construct validity was supported as > 75% of the hypotheses were confirmed. Internal consistency (Cronbach α’s from 0.81 to 0.95) was good in the pooled and separate pre- and postoperative samples and test–retest reliability (Intraclass Correlation Coefficients (ICCs) from 0.63 – 0.85) were good in postoperative patients and moderate in preoperative patients. The standard Error of Measurements (SEMs) ranged from 8.5 – 12.2 and the Smallest Detectable Changes in individuals (SDC_ind) ranged from 23.5 – 34.0 (on a scale from 0 to 100).

Conclusions

Preliminary findings suggest that the Dutch version of the OKS-APQ is reliable and valid for a Dutch postoperative TKA patient sample. However, in a preoperative TKA sample, the OKS-APQ seems less suitable, because of floor effects and lower test–retest reliability. The Dutch version of the OKS-APQ can be used alongside the OKS to discriminate among levels of activity and participation in postoperative patients.

Translation, cross-cultural adaptation and psychometric properties of the Urdu version of knee injury and osteoarthritis outcome score questionnaire for Pakistani population

Background

Knee injury and osteoarthritis outcome score questionnaire is a widely used tool for measuring short and long-term patient-relevant outcomes following knee injury. KOOS is neither translated nor examined for psychometric properties before. Therefore, the aim of this study was to translate, culturally adapt and check the psychometric properties of the KOOS in Urdu.

Methodology

The translation and cultural adaptation was performed according to pre-defined guidelines. A total of 117 participants (54 males and 63 females) were recruited. The study had two steps: 1) Translation and cultural adaptation 2) Reliability and validity testing. The reliability (test-retest and internal consistency at (95% confidence interval) as well as the validity (Convergent validity) of final Urdu version of KOOS was tested.

Results

For all five domains, the KOOS Urdu version (KOOS-U) has demonstrated high test-retest reliability ICC = 0.90–0.96(CI = 95%). For all domains, the internal consistency was determined to be excellent (α = 0.82–0.96). There were no floor or ceiling impacts noted. Convergent validity was found to be good, as measured by Pearson’s correlation coefficient. The findings revealed a strong negative association between the KOOS-U (QOL and pain) and the NPRS. And there was a low to high positive correlation between five KOOS-U domains and all SF-12 domains, i.e., there was a significant positive correlation between the pain domains of both KOOS and SF-12 with the r = 0.87(p < 0.05).

Conclusion

The Urdu version of KOOS is a valid, reliable, and responsive instrument to assess functional disability of patients with Knee Osteoarthritis with excellent psychometric properties.

Cross-cultural translation and validation of the Chinese Oxford Knee Score and the Activity and Participation Questionnaire

OBJECTIVE

To cross-culturally translate and validate the Chinese versions of the Oxford Knee Score (OKS) and the Activity and Participation Questionnaire (APQ) in patients with end-stage knee osteoarthritis who are also candidates for knee replacement.

METHODS

The Chinese version of the OKS and APQ was completed by standard forward-backward translation and adaption. The feasibility was validated by a pretest in 30 patients. The final version together with the Short Form-36 (SF-36), EQ-5D, and EQ visual analog scale were assessed in 150 patients, and the OKS and APQ were repeated in 30 patients after a 2-week interval. The psychometric properties of the OKS and APQ were evaluated for test-retest reliability using intraclass correlation coefficients (ICCs), internal consistency using Cronbach's α, and construct validity using Spearman's correlation analysis.

RESULTS

All patients were able to understand and complete both the OKS and APQ without difficulty (i.e. no missing data). The ICCs were 0.959 for the OKS, 0.956 for the APQ for total scores, and >0.7 for each item. Cronbach's α was greater than 0.7, and the corrected item-total correlation was greater than 0.4 for each item of both questionnaires. The OKS and APQ showed better correlations with questions from the pain and function domains than with those from the mental status domains of the SF-36 and EQ-5D. No floor or ceiling effect was identified in either questionnaire.

CONCLUSIONS

The Chinese versions of the OKS and APQ are easy to understand and complete and showed good reliability and validity. They can be used to assess patient-reported outcomes after undergoing knee replacement in mainland China.

The outcomes of mobile bearing unicompartmental knee arthroplasty and total knee arthroplasty on anteromedial osteoarthritis of the knee in the same patient

INTRODUCTION

Compared to total knee arthroplasty (TKA), mobile-bearing unicompartmental knee arthroplasty (UKA) is associated with better outcomes, such as an earlier recovery, less postoperative pain, lower morbidity and mortality, and a greater "feel" of a normal knee. However, no study has reported the clinical outcomes in patients with the same stage of osteoarthritis of the knee. The purpose of this study was to determine the clinical outcomes, including the Joint Forgotten Score (JFS), Oxford Knee Score (OKS), Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Kujala score after UKA on one knee and TKA on the opposite knee in the same patient.

MATERIALS AND METHODS

We retrospectively reviewed 32 patients with anteromedial OA who underwent mobile-bearing UKA in one knee and TKA in the other knee from 2009 to 2017. The JFS, OKS, KSS, KOOS, and Kujala scores were recorded and compared between the groups. Patients' preferences between UKA and TKA and satisfaction were also recorded.

RESULTS

The JFS and KOOS in the UKA group were significantly (p = 0.01, 0.01) higher than those in the TKA group: 97.01 ± 3.26 (89.58-100) vs. 94.92 ± 3.34 (87.80-100) and 91.16 ± 2.67 (85.25-96) vs. 89.24 ± 2.67 (84.50-94.71), respectively. The OKS, KSS, and Kujala scores were not different between the two groups (p = 0.82, 0.95, and 0.31, respectively) and neither was patient preference (p = 0.41) or satisfaction (p = 0.42). The mean follow-up was 48.36 months (range 24.00-96.00 months), during which there were no postoperative complications.

CONCLUSION

UKA was associated with a better JFS and KOOS but was otherwise comparable to TKA and may be preferable.

Validation of the Oxford Knee Score and Lower Extremity Functional Score questionnaires for use in Slovenia

BACKGROUND

With the increasing prevalence of total knee replacement (TKR) due to knee osteoarthritis, the absence of patient-reported outcome measures in Slovenia must be addressed.

QUESTIONS/PURPOSES

(1) We cross-culturally adapted Oxford Knee Score (OKS) and Lower Extremity Functional Scale (LEFS) questionnaires to the Slovenian-speaking community. (2) We evaluated OKS and LEFS psychometric characteristics.

PATIENTS AND METHODS

In the first assessment (Time 1) Slovenian versions of both questionnaires (OKS-Slo and LEFS-Slo), knee pain, timed-up to go (TUG) and sit to stand (STS) tests were completed by 123 subjects (55% females), of which 78 were patients scheduled for TKR and 45 were healthy age-matched controls. The questionnaires were assessed one week apart (Time 2) to investigate the test-retest reliability, with 121 subjects (98.4%) completing second measurements.

RESULTS

Significant differences were observed between the two groups. Where patients had greater body mass index, they were slower in TUG, weaker in STS, had greater knee pain in both knees and scored lower on both questionnaires. Additionally, correlation analysis showed that OKS-Slo and LEFS-Slo correlated almost perfectly (correlation coefficient [CC] = .968, p < 0.001). Excellent negative correlations were observed with TUG (OKS-Slo/CC = - 0.679, p < 0.001; LEFS-Slo/CC = - 0.692, p < 0.001) and STS (OKS-Slo/CC = 0.790, p < 0.001; LEFS-Slo/CC = 0.815, p < 0.001) tests, while knee pain of affected leg correlated the most (OKS-Slo/CC = - 0.923, p < 0.001; LEFS-Slo/CC = - 0.915, p < 0.001). The Cronbach's alpha coefficient for both the OKS-Slo and LEFS-Slo ranged between 0.87 and 0.99, while the interclass correlation coefficient was excellent; i.e., 0.99. Finally, both questionnaires proved to be unidimensional measures.

CONCLUSION

The Slovenian version of both questionnaires is feasible, valid and reliable for use in clinical studies including the older adult population in Slovenia.

LEVEL OF EVIDENCE

Level III, Diagnostic-case-control study.

Safety and efficacy of sequential simultaneous bilateral total knee arthroplasty: A single centre retrospective cohort study

BACKGROUND

Simultaneous bilateral total knee arthroplasty (TKA) is a promising option for patients with bilateral arthritis of the knee because of the requirement of a single hospitalization and anesthetic regimen, reduced overall hospital stay, lower overall costs, and quicker recovery compared to staged bilateral TKA. However, there are conflicting reports on the safety of the procedure, with little data available in the Indian setting. Herein, we compared the efficacy and safety of sequential simultaneous bilateral TKA (SSBTKA) with those of unilateral TKA (UTKA).

METHODS

This retrospective analysis included cases of SSBTKA (n = 380, 760 knees) and UTKA (n = 754) performed by the same surgeon and followed up for a minimum duration of 1 year. The functional outcomes (postoperative changes in Oxford Knee Score [OKS] and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), length of hospital stay (LOS), complications, and rates of revision and mortality were compared between the two groups.

RESULTS

The mean follow-up durations were 40.59 and 36.69 months for the UTKA and SSBTKA groups, respectively. The LOS was significantly longer in the SSBTKA group than in the UTKA group (Median [Interquartile range]: 4[1] vs. 3[0], p < 0.001). The OKS and WOMAC scores increased with time in both groups. The improvements in each of these scores at 3, 6, and 12 months postoperatively were either statistically similar between the two groups or, if statistically different, the differences were too small to be clinically meaningful. Blood transfusions (4% [SSBTKA] vs.0.3% [UTKA], p < 0.001), cardiac complications (1.6% vs. 0.4%, p = 0.034), urine retention (3.7% vs. 1.2%, p = 0.005), and deep infection (0.8% vs. 0%, p = 0.015) were significantly more frequent in the SSBTKA group. None of the patients in the UTKA group had to undergo revision surgery, whereas in the SSBTKA group, 2 (0.6%) patients underwent revision TKA. The overall mortality rates were low in both groups (0.8% [SSBTKA] and 0.3% [UTKA]), with no significant between-group difference (p = 0.209).

CONCLUSION

The functional outcomes and mortality rates associated with SSBTKA are comparable to those associated with UTKA. The risk of complications and the need for revision, although higher with SSBTKA, the actual numbers are low enough to justify its use. Although the LOS in SSBTKA is longer than that in UTKA, it is likely to be shorter than the cumulative LOS for two UTKA procedures (i.e. a staged bilateral TKA). Thus, SSBTKA appears to be a safe and effective choice for appropriately selected patients.

Mapping analysis to predict EQ-5D-5 L utility values based on the Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires in the Spanish population suffering from lower limb osteoarthritis

BACKGROUND

The EQ-5D-5 L is a quality-of-life questionnaire based on individuals' preferences that is widely employed for cost-effectiveness analysis. Given the current demand for mapping algorithms to directly assign "utilities", this study aimed to generate different mapping models for predicting EQ-5D-5 L utility values based on scores of the Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires provided by patients suffering from hip and knee osteoarthritis (OA), respectively, and to assess the predictive capability of these functions.

METHODS

This was a prospective, observational study. Following the criteria of the American Rheumatism Association, 361 patients with hip OA and 397 with knee OA from three regions in Spain were included. Health-related quality of life (HRQoL) was assessed through the EQ-5D-5 L general questionnaire and the OHS and OKS specifically for lower limb OA. Based on the scores on the OHS and OKS questionnaires, EQ-5D-5 L utilities were estimated using 4 models: ordinary least squares (OLS), Tobit, generalized linear model (GLM), and beta regression (Breg). The models were validated on the same patients after 6 months: the mean absolute error (MAE) and mean squared error (MSE) with their 95% confidence intervals (CI), mean values of standard errors (SE), intraclass correlation coefficients (ICC), and Bland-Altman plots were obtained.

RESULTS

The lowest MAEs were obtained using GLM and Breg models, with values of 0.1103 (0.0993-0.1214) and 0.1229 (0.1102-0.1335) for hip OA, and values of 0.1127 (0.1014-0.1239) and 0.1141 (0.1031-0.1251) for knee OA. MSE values were also lower using GLM and Breg. ICCs between predicted and observed values were around or over the 0.8 cut-off point. Bland-Altman plots showed an acceptable correlation, but precision was lower for subjects with worse HRQoL, which was also evident when comparing MAEs of the bottom and top halves of the utilities scale. Predictive equations for utilities based on OHS/OKS scores were proposed.

CONCLUSIONS

The OHS and OKS scores allow for estimating EQ-5D-5 L utility indexes for patients with hip and knee OA, respectively, with adequate validity and precision. GLM and Breg produce the best predictions. The predictive power of proposed equations is more consistent for subjects in better health condition.

Functional outcome of total knee replacement: a study protocol for a prospective, double-blinded, parallel-group randomized, clinical controlled trial of novel, personalized and conventional implants

BACKGROUND

The development of total knee replacement (TKR) implant designs aims to improve outcome regarding pain, function, joint stiffness, instability, patellar problems, and ultimately wear of the implant. Recently, two major orthopaedic implant manufacturers launched a new generation of TKR implants which, according to the manufacturers, provide improved functional outcome. However, the benefits of these new TKR designs claimed by the manufacturers in terms of improved functional outcome still lack scientific documentation. The present randomized controlled trial has been designed to compare three fixed bearing, cemented cruciate-retaining (CR) designs; one of the new personalized TKR design with two conventional TKR designs with the main emphasis being on functional outcome.

METHODS

The present study is a prospective, double-blinded, randomized, single-center intervention trial. A total of 240 patients will be recruited to participate in a parallel-group study at Coxa Hospital for Joint Replacement, Tampere, Finland. We will compare the short-term functional outcome of TKR performed with a novel personalized TKR design (Persona CR, Zimmer, Warsaw, IN, USA) against TKRs performed with two conventional designs (PFC CR, DePuy, Warsaw, IN, USA and Nexgen CR, Zimmer, Warsaw, IN, USA). In total, 80 patients will be randomized in each of the three study arms. The primary outcome in this study is the Oxford Knee Score (OKS), which is a validated patient-reported outcome measure (PROM). Secondary outcome measures include the Forgotten Joint Score, the 15D, the UCLA activity score, and the VAS pain scale. The results will be analyzed after 2-year follow-up.

DISCUSSION

This paper presents a prospective, randomized, single-center trial study protocol. It provides details of patient randomization, PROMs, follow-up, methods of analysis of the material, and publication plan. An important aspect that will be considered in the study will be the economic effects of the novel designs as they are substantially more expensive, and the benefits of the added costs remain unknown. In addition, it is especially important to carry out evaluative studies in independent centers that are not biased by the interests of the manufacturers.

TRIAL REGISTRATION

Retrospectively registered, November, 2017, ClinicalTrials.gov Identifier: NCT03339557 .

Pain relieve without impairing muscle function after local infiltration anaesthesia in primary knee arthroplasty: a prospective randomized study

PURPOSE

Purpose of the current study was to compare early effectiveness of pain relieve of 3 in 1 regional pain catheter to local infiltration anesthesia (LIA) in primary total knee arthroplasty (TKA). Secondary endpoint was quadriceps muscle strength after both procedures.

MATERIAL AND METHODS

A single-center, prospective, randomized controlled trial was performed. Patients eligible to TKA were either randomized into group 3 in 1 regional pain catheter (C), or group local infiltration anesthesia (L). Pain relieve was assessed by visual analogue scale (VAS) at rest and under physical activity (PA) prior to surgery (t0) and at days one through six. In addition, quadriceps muscle strength ( = straight leg raise) was tested according to the Manual Muscle Testing Scale. Functional outcome was measured using the Oxford Knee Score (OKS) preoperatively and 6 months postoperatively.

RESULTS

121 patients were included in the study. 59 (48.8%) patients were allocated to group C, 62 (51.2%) patients to Group L. No differences concerning pain level evaluated by VAS could be detected between the groups at any time. Comparing straight leg raise test group L was significantly superior over the complete postoperative period (p < 0.03). The mean OKS decreased significantly (p < 0.001) from preoperatively 34.2 ± 7.5 points to 16.9 ± 6.0 points at the six months final follow-up. Regarding OKS there were no intergroup differences at the final follow-up at 6 months postoperative.

CONCLUSION

There is no significant difference in pain relieve comparing LIA to 3 in 1 catheter in perioperative pain management in TKA. The advantage of LIA is unimpaired quadriceps muscle function in the short-term follow-up.

Arabic translation and validation of three knee scores, Lysholm Knee Score (LKS), Oxford Knee Score (OKS), and International Knee Documentation Committee Subjective Knee Form (IKDC)

Aim of the work: Translation and validation of three commonly used knee scores to Arabic language: the Lysholm Knee Score (LKS), the Oxford Knee Score (OKS), and IKDC Subjective Knee Form.

Methods: Our work focused on translation and validation of the LKS, OKS and IKDC. Construct validity was assessed by comparing the LKS, OKS, and IKDC Subjective Knee Form and previous Arabic translated version of Knee injury and Osteoarthritis Outcome Score (KOOS). Test−retest reliability, internal consistency, and construct validity were assessed, using Intraclass Correlation Coefficient (ICC), Cronbach's alpha, and Pearson correlation coefficient (r).

Results: Reliability was excellent for the Arabic IKDC subjective form (0.95), while the Arabic LKS and the Arabic OKS were good: 0.8 and 0.85, respectively. The Cronbach's ά was excellent for the Arabic LKS and Arabic OKS: 0.9 and 0.90, respectively, while the Arabic IKDC subjective form was good (0.89). Construct validity was high for the Arabic LKS and the Arabic OKS: 0.7 and 0.913, respectively, while the Arabic IKDC was moderate (0.4) in cases of ACL and meniscus injuries and mild (0.18) in cases of osteoarthritis.

Conclusion: Arabic LKS and Arabic OKS were reliable and valid scores for patients complaining of ligamentous injuries, meniscus injuries, and osteoarthritis to be used for Arabic-speaking people, while the Arabic IKDC had excellent reliability and mild validity in cases of osteoarthritis and moderate validity in cases of ACL and meniscus injuries.

Validation of the Chinese (Mandarin) Version of the Oxford Knee Score in Patients with Knee Osteoarthritis

BACKGROUND

With the increasing number of patients with knee osteoarthritis undergoing TKAs in China, there is a clear need for a valid, short, joint-specific patient-reported outcome measure such as the Oxford Knee Score (OKS).

QUESTIONS/PURPOSES

To test the translated and cross-culturally adapted Chinese (Mandarin) version of the Oxford Knee Score (OKS-CV) and its (1) reliability, (2) construct validity, (3) dimensionality, and (4) responsiveness.

METHODS

Three native Chinese bilingual translators (a professional English translator, an experienced orthopaedic surgeon, an advanced-practice nursing specialist) translated the English-language OKS into Mandarin Chinese. A consensus panel created a synthesis of those efforts, which then was back-translated by two bilingual nonmedical, professional English-language translators. The OKS-CV was developed according to the guidelines of copyright holders. Between March 2013 and March 2015, 253 patients underwent TKAs. Among them, 114 Mandarin-speaking patients with knee osteoarthritis underwent primary unilateral TKA (age, 67 ± 7 years; range, 55-84 years; female, 80%; preoperatively 54% had moderate to severe knee osteoarthritis), completed the preoperative questionnaires, and were followed up, with a mean postoperative followup of 2.7 years (SD, 0.5 years). Eligibility criteria were (1) patients with knee osteoarthritis who were scheduled to have a primary unilateral TKA, (2) patients who were fluent in Mandarin, and (3) consent to participate. The exclusion criteria were: (1) lack of understanding of Mandarin, and (2) inability to comprehend the questionnaires owing to cognitive impairment. To evaluate test-retest reliability, another group of 35 Mandarin-speaking outpatients with knee osteoarthritis (age, 61 ± 10 years; range, 44-84 years; female, 77%) was recruited to complete the OKS-CV twice at a 1-week interval. Reliability was tested using Cronbach's alpha and intraclass correlation coefficient (ICC). Construct validity was evaluated using Spearman's rank correlation coefficient to quantify the correlations between the OKS-CV and the WOMAC, Short Form-8 Health Survey (SF-8^TM), and EuroQol Group 5-Dimension Self-Report Questionnaire (EQ-5D). Exploratory factor analysis was performed to clarify dimensionality. The eigenvalue indicates the importance of each factor obtained from factor analysis. Responsiveness was determined by standardized response mean (SRM) and effect size (ES) from preoperative and postoperative scores of the OKS-CV. Floor and ceiling effects also were analyzed.

RESULTS

The internal consistency (Cronbach's alpha = 0.89) and test-retest reliability (ICC = 0.93; 95% CI, 0.87-0.97) proved good. Convergent construct validity was supported by moderate to strong correlations between the OKS-CV and the WOMAC (r = -0.80, p < 0.001), the SF-8^TM physical component summary (r = 0.65, p < 0.001), and the EQ-5D usual activities (r = -0.41, p < 0.001) and mobility (r = -0.35, p < 0.001). There also were correlations between the OKS-CV and the SF-8^TM mental component summary (r = 0.58, p < 0.001) and the EQ-5D anxiety/depression (r = -0.35, p < 0.001). The factor analysis yielded three factors with eigenvalues greater than 1. Responsiveness was excellent (SRM = 1.52; ES = 1.52). No floor or ceiling effect was observed.

CONCLUSIONS

The OKS-CV showed good acceptability and psychometric properties for the intended population. Future studies are needed to evaluate the mental state of patients with knee osteoarthritis.

CLINICAL RELEVANCE

The OKS-CV appears to be a reliable, valid, and responsive instrument for Chinese patients with knee osteoarthritis. Based on these results we believe the OKS-CV can be used as a valuable tool for the assessment of patient-reported outcomes in Chinese patients with knee osteoarthritis before and after TKA.

Validation of the Spanish version of the Oxford knee score and assessment of its utility to characterize quality of life of patients suffering from knee osteoarthritis: a multicentric study

Background

Knee osteoarthritis (OA) represents a heavy burden for patients and the society as a whole. The Oxford Knee Score (OKS) is a well known tool to assess the quality of life in patients with Knee OA. The purpose of this study was to analyze the psychometric properties of the Spanish version of the OKS, including its reliability, validity, and responsiveness.

Methods

Prospective observational study that included 397 patients diagnosed with knee OA according to the criterion of the American Rheumatism Association, which were recruited in 3 different Spanish regions. Their self-perceived health-related quality of life (HRQL) was assessed through 3 questionnaires: a generic one (the EQ-5D-5 L) and two specific ones adapted to Spanish (the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Oxford Knee Score (OKS). The follow-up period was 6 months, and the acceptability of the OKS was evaluated, together with its psychometric properties, presence of ceiling and floor effects, validity, reliability, and sensitivity to change.

Results

The OKS was fully answered in 99.5% of cases, with no evidence of ceiling or floor effects. Its factor structure can be explained in a single dimension. Its discriminating capacity was very good compared to the groups generated by the WOMAC and the EQ-5D-5 L. The correlation of the OKS with the dimensions of the latter questionnaires was around 0.7. The test-retest reliability was excellent (ICC 0.993; CI 95%: 0.990–0.995) and so was its internal consistency (Cronbach’s α = 0.920). The effect size was 0.7 for moderate improvements in the HQRL, which is similar to that of the dimensions of the WOMAC and greater than for the EQ-5D-5 L. The minimum clinically significant difference that was detected by the questionnaire was 6.1 points, and the minimum detectable change was 4.4 points.

Conclusions

The Spanish-adapted version of the OKS is a useful, valid tool for assessing the perceived HRQL in patients suffering from knee OA, with psychometric properties similar to the WOMAC, and that allows for discriminating the patient’s condition at a particular moment as well as for appraising changes over time.

Electronic supplementary material

The online version of this article (10.1186/s12955-017-0761-2) contains supplementary material, which is available to authorized users.