Clinimetric quality of the new 2011 Knee Society score: high validity, low completion rate

A clinical risk score enables early prediction of dissatisfaction 1 year after total knee arthroplasty

PURPOSE

Dissatisfaction after total knee arthroplasty (TKA) is a prevalent and clinically relevant problem that affects approximately 10%-20% of patients. The aim of this study is to identify factors associated with dissatisfaction 1 year after TKA.

METHODS

A total of 236 patients undergoing TKA were included in this prospective cohort study. Demographic data, preoperative clinical parameters (e.g., axial alignment, osteoarthritis severity) and patient-reported outcome measures (PROMs) were collected preoperatively, at 1 month and 1 year after TKA, encompassing the Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). The primary outcome was dissatisfaction 1 year after TKA, defined as ≤20 points on the KSS satisfaction scale. A risk score based on multiple regression and area under the curve (AUC) analyses was calculated to predict dissatisfaction.

RESULTS

One year after TKA, 16% of the patients were dissatisfied. Dissatisfied patients were significantly younger (p = 0.023) and had a higher body mass index (BMI) (p = 0.007). No differences were observed in preoperative objective (p = 0.903) and functional KSS (p = 0.346), pain (p = 0.306), osteoarthritis severity (p = 0.358), axial knee alignment (p = 0.984) or psychological distress (p = 0.138). The likelihood of dissatisfaction at 1 year was 3.0, 4.0, 7.4, 4.3 and 2.8 times higher amongst patients aged <63.5 years, with a BMI > 30.1 kg/m2, a KOOSPain < 50%, a KSSFunction < 42 points and a KSSExpectation < 9 points (all at 1 month), respectively. Using these variables, a risk score with a maximum of 7 points was developed, demonstrating a high predictive value for dissatisfaction (AUC: 0.792 [95% confidence interval: 0.700-0.884], p < 0.001).

CONCLUSION

Dissatisfaction 1 year after TKA can be predicted by a weighted risk score that includes patient age, BMI, pain, subjective functionality and unmet expectation 1 month postoperatively. Using the risk score, early detection of dissatisfaction has the potential to enable targeted interventions and improve patients' quality of life.

LEVEL OF EVIDENCE

Level II, Prognostic study.

Assessing knee functionality: systematic review of validated outcome measures

BACKGROUND

Functional rating scales allow clinicians to document and quantify alterations and progression of recovery processes. There is neither awareness of numerous knee scales nor are they easy to find or compare to select the most suitable.

OBJECTIVES

We aimed to compile validated knee functional rating tools and analyse the methodological quality of their validation studies. Also, we aimed to provide an operational document of the outcome measures addressing descriptions of parameters, implementations, instructions, interpretations and languages, to identify the most appropriate for future interventions.

METHODS

A systematic review involved a search of PubMed, Web of Science, CINAHL, Scopus, and Dialnet databases from inception through September 2020. The main inclusion criteria were available functional rating scales/questionnaires/indexes for knees and validation studies. Methodological quality was analyzed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and COnsensus-based Standards for the selection of health Measurement Instruments Risk of Bias (COSMIN-RB).

RESULTS

We selected 73 studies. The studies investigated 41 knee rating tools (general, 46%, and specific, 54%) and 71 validations, including 29,742 individuals with knee disorders. QUADAS-2 obtained the best results in patient selection and index test (applicability section). COSMIN-RB showed the highest quality in construct validity (most analyzed metric property). The specific tools were mainly designed for prosthesis and patellofemoral and anterior cruciate ligament injuries. More considered issues were specific function (93%), especially gait, pain/sensitivity (81%), and physical activity/sports (56%).

CONCLUSIONS AND IMPLICATIONS

We conducted a necessary, useful, unlimited-by-time and feasible compilation of validated tools for assessing knee functional recovery. The methodological quality of the validations was limited. The best validations were for the Copenhagen Knee Range of Motion Scale in osteoarthritis and arthroplasties, Knee Outcome Survey Activities of Daily Living and Lysholm Knee Score for general knee disorders and the Tegner Activity Score for anterior cruciate ligament injuries. The operational document for the scales provides necessary data to identify the most appropriate.

Outcomes of Total Knee Arthroplasty in Patients With Rheumatoid Arthritis

The purpose of this study was to examine current literature regarding the efficacy of total knee arthroplasty for patients with rheumatoid arthritis. Studies that assessed total knee arthroplasty outcomes in patients with rheumatoid arthritis were identified on MEDLINE from January 2009 to November 2018. All 4 studies that assessed knee pain and 9 of 11 studies that assessed knee function noted significant improvement in average knee score. However, between 10% and 47% of patients had significant knee pain at final follow-up. Total knee arthroplasty provides significant improvement in knee pain and function for patients with rheumatoid arthritis. However, the rates of postoperative pain vary widely. [Orthopedics. 2021;44(5):e626-e632.].

Short-Form New Knee Society Score: What Is Its Responsiveness and Convergent Validity with Other Scores?

The short-form version of New Knee Society Score (SF-NKSS) was designed with a purpose to reduce respondent burden. Literature review revealed only one report by Scuderi et al on responsiveness of derived SF-NKSS, but it was evaluated in two separate patient cohorts pre- and postsurgery. Our study had evaluated responsiveness and convergent validity of derived SF-NKSS in a single, large patient cohort followed longitudinally from preoperative status to over 1 year. Our database of 148 knee arthroplasty patients operated by the same surgeon, whose NKSS, Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 12-item Short-Form Survey (SF-12) scores were prospectively collected preoperatively and postoperatively at 3 and 12 months for a study published earlier, was analyzed for derived SF-NKSS. Responsiveness was evaluated by determining the effect size, standardized response mean (SRM), and ceiling and floor effects. For convergent validity, Pearson's correlation coefficient was used. SF-NKSS was found to be most responsive with the largest effect size and SRM at 3 months (3.02 and 2.50, respectively) and at 12 months (3.58 and 2.92, respectively) with no ceiling or floor effect. SF-NKSS was followed in responsiveness by original NKSS, WOMAC, and SF-12 in a descending order. Convergent validity showed a strong correlation (r = 0.8-1.0; p < 0.001) of SF-NKSS with NKSS and a moderate to strong correlation (r = 0.5-0.6; p < 0.001) with WOMAC and SF-12. We concluded that SF-NKSS is a reliable, highly responsive tool for post-total knee replacement evaluation. It also has the ability to register improvement in the patient's recovery, which can continue even after 1 year. We found that the SF-NKSS can be used interchangeably with the original NKSS.

A new prediction model for patient satisfaction after total knee arthroplasty and the roles of different scoring systems: a retrospective cohort study

BACKGROUND

Although total knee arthroplasty (TKA) is an efficacious treatment for end-stage osteoarthritis, ~20% of patients are dissatisfied with the results. We determined which factors contribute to patient satisfaction and compared the various scoring systems before and after surgery.

METHODS

In this retrospective cohort study, 545 patients were enrolled and evaluated preoperatively and 1 year postoperatively. Patient demographics, as well as scores for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF)-12, and 1989 Knee Society Clinical Rating System (1989 KSS), were recorded preoperatively and postoperatively. The possible predictors were introduced into a prediction model. Scores for overall satisfaction and the 2011 Knee Society Score (2011 KSS) were also assessed after TKA to identify the accuracy and agreement of the systems.

RESULTS

There were 134 male patients and 411 female patients, with an overall prevalence of satisfaction of 83.7% 1 year after surgery. A history of surgery (p < 0.001) and the 1989 KSS and SF-12 were of the utmost importance in the prediction model, whereas the WOMAC score had a vital role postoperatively (change in WOMAC pain score, p < 0.001; change in WOMAC physical function score, p < 0.001; postoperative WOMAC pain score, p = 0.004). C-index of model was 0.898 > 0.70 (95% confidence interval (CI): 0.86-0.94). The Hosmer-Lemeshow test showed a p value of 0.586, and the AUC of external cohort was 0.953 (sensitivity=0.87, specificity=0.97). The agreement between the assessment of overall satisfaction and the 2011 KSS satisfaction assessment was general (Kappa=0.437 > 0.4, p < 0.001).

CONCLUSION

A history of surgery, the preoperative 1989 KSS, and the preoperative SF-12 influenced patient satisfaction after primary TKA. We recommend the WOMAC (particularly the pain subscale score) to reflect overall patient satisfaction postoperatively.

Evolving Outcome Measures in Total Knee Arthroplasty: Trends and Utilization Rates Over the Past 15 Years

BACKGROUND

Patient-reported outcome metrics and reporting are important for demonstrating value associated with total knee arthroplasty (TKA). This review studied the patient-reported outcome utilization trends as reported within the TKA literature over a 15-year period.

METHODS

A PubMed search of all manuscripts related to TKA from January 2005 to December 2019 was performed. Descriptive statistics were used for individual outcome metrics as proportions of total article publications focusing on TKA outcomes. Linear regressions analysis was performed to demonstrate significant changes in utilization rates over time.

RESULTS

There was a significant overall increase in studies utilizing outcome metrics between 2005 and 2019 (16.1%-45.0%; P < .001; R² = 98.7%). Within joint-specific metrics (2005-2019), use of Knee Disability and Osteoarthritis Outcome score increased (0%-14.8%; P < .001); while use of Knee Society Knee Scoring System decreased (55.2%-35.4%; P = .007). Of the studies reporting general health, use of the Forgotten Joint Score-12 decreased (100%-66.7% from 2014 to 2019; P = .006), and Patient-Reported Outcome Measurement Information System Global-10 increased (0%-21.4% from 2005 to 2019; P < .001). In the quality of life subcategory (2005-2019), EuroQol 5-Dimension Health Outcome Survey increased in usage (14.3%-28.0%; P < .001), while Short Form-36 use decreased (85.7%-36.6%; P < .001).

CONCLUSION

Although utilization of outcome metrics has significantly increased over the last 15 years in the TKA literature, there still exists considerable heterogeneity of outcome metrics. This lack of consensus may impede comparisons of studies for clinical and research purposes, as well as hinder cross-walk of outcome tools over time. Further study is needed to identify ideal global and joint-specific tools, while balancing issues like ease of use and utility in specific populations such as the young and highly active.

Comparative Effect between Infiltration of Platelet-rich Plasma and the Use of Corticosteroids in the Treatment of Knee Osteoarthritis: A Prospective and Randomized Clinical Trial

Objectives  This study aimed to analyze the efficacy of platelet-rich plasma obtained from the peripheral, autologous blood of the patients in pain complaints reduction and functional improvement of knee osteoarthritis compared with the standard treatment with injectable corticosteroid, such as triamcinolone.

Methods  The patients were followed-up clinically at the preinfiltrative visit, with quantitative evaluation using the Knee Society Score (KSS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and the Kellgren and Lawrence scales. In addition, they were reevaluated with the same scales after 1 month and 6 months of intervention with 2.5 mL of triamcinolone acetate or 5 mL of platelet-rich plasma. The study was performed on 50 patients with knee osteoarthritis treated at the Medical Specialty Center and randomly divided into equivalent samples for each therapy.

Results  The present study verified the reduction of pain scores, such as the WOMAC score, and elevations of functional scales, such as the KSS, evidenced in 180 days when using platelet-rich plasma, a therapy that uses the autologous blood of the patient and has fewer side effects.

Conclusion  Although both platelet-rich plasma and corticosteroid therapies have been shown to be effective in the reduction pain complaints and functional recovery, there was a statistically significant difference between them at 180 days. According to the results obtained, platelet-rich plasma presented longer-lasting effects within 180 days in the treatment of knee osteoarthritis.

Translation, cross-cultural adaptation, and validation of the Italian language Forgotten Joint Score-12 (FJS-12) as an outcome measure for total knee arthroplasty in an Italian population

Background

With ever-increasing numbers of patients undergoing elective total knee arthroplasty (TKA) and as TKA is performed in increasingly younger patients, patient demands and expectations have also increased. With improved patient outcomes, new PROMs with heightened discriminatory power in well-performing patients are needed. The present study aimed to translate and validate the Italian version of the Forgotten Joint Score (FJS-12) as a tool for evaluating pre-operative through longitudinal post-operative outcomes in an Italian population.

Methods

In this prospective study, patients with unilateral osteoarthritis, undergoing TKA surgery between May 2015 and December 2017 were recruited to participate in the study. The FJS-12 and WOMAC were collected pre-operatively and at six and 12 months post-operatively. According to the COSMIN checklist, reliability, internal consistency, validity, responsiveness, effect size, and ceiling effects and floor effects were evaluated.

Results

One hundred twenty patients completed the study, 66 of which participated in the evaluation of test-retest reliability. Good test-retest reliability was found (ICC = 0.90). The FJS-12 also showed excellent internal consistency (Cronbach α = 0.81). Construct validity with the WOMAC, as a measure of the Pearson correlation coefficient, was moderate (r = 0.45 pre-operatively; r = 0.46 at 6 months and r = 0.42 at 12 months post-operatively). From six to 12 months, the change was slightly greater for the WOMAC than for the FJS-12 patients (effect size d = 0.94; d = 0.75, respectively). At 12-months follow-up, the ceiling effects reflecting the maximum score were 12% for the FJS-12 and 6% for the WOMAC; however, scores within 10% of the maximum score were comprised 30% of the FJS-12 scores and 59% for the WOMAC.

Conclusion

The Italian FJS-12 demonstrated strong measurement properties in terms of reliability, internal consistency, and construct validity in TKA patients. Furthermore, a more detailed look at ceiling effects shows a superior discriminatory capacity when compared to the WOMAC at 12-months follow-up, particularly in better-performing patients.

Trial registration

clinicaltrials.gov NCT03805490. Registered 18 January 2019 (retrospectively registered).

Influence of limb alignment and prosthetic orientation on patient-reported clinical outcomes in total knee arthroplasty

BACKGROUND

The relationship between postoperative limb alignment and clinical outcomes in primary total knee arthroplasty (TKA) is well reported, but the instruments used to evaluate clinical outcomes of TKA are mainly scoring systems from the physician's viewpoint, not patient-reported outcomes. The purpose of this study was to investigate retrospectively the relationship between postoperative limb alignment and patient-reported clinical outcomes using the 2011 Knee Society Knee Scoring System (2011 KSS).

METHODS

The present study included 155 knees of patients (median age, 74 years) who underwent primary TKA for varus osteoarthritis, with a mean follow-up period of 46 months. The subjects were divided into three groups based on postoperative limb alignment and femoral and tibial component positioning angle (varus, neutral, and valgus). The 2011 KSS scores were compared among the groups.

RESULTS

For limb alignment, the postoperative objective knee indicator score was significantly lower in the valgus group than in the varus and neutral groups, whereas no significant differences were observed in any subjective categories of the 2011 KSS. However, for the femoral component angle, functional activity scores were significantly lower in the valgus group than in the varus and neutral groups.

CONCLUSIONS

The subjective patient-reported score was not affected by the postoperative limb alignment. However, the valgus femoral component angle resulted in lower subjective functional scores. For clinical relevance, postoperative valgus positioning of femoral component should be avoided from patient-reported functional aspects during TKA.

Effects of Enhanced Recovery After Surgery in Total Knee Arthroplasty for Patients Older Than 65 Years

OBJECTIVES

To explore the safety and efficacy of the enhanced recovery after surgery (ERAS) program for elderly total knee arthroplasty (TKA) patients.

METHODS

A prospective controlled study was conducted for patients older than 65 years, who would undergo unilateral TKA with a minimum follow-up of 2 years. Patients were divided into an ERAS group (n = 106) and a traditional group (n = 141) based on the patients' willingness to participate in the ERAS program. Baseline parameters of American Society of Anesthesiologists classification and comorbidity were recorded. Complication, mortality, knee function assessment using knee society score and knee range of motion, and perioperative clinical outcomes were compared between the two groups.

RESULTS

There were no significant differences between the two groups in terms of baseline parameters. Although no significant differences were found in postoperative nausea and vomiting, urinary tract infection, deep venous thrombosis, pulmonary embolism, wound delayed healing, superficial infection, and deep infection, there were significantly fewer total complications in the ERAS group (26/106 vs 52/141; P = 0.039). No significant difference was found in short-term mortality (1/106 vs 3/141; P = 0.836) between the two groups. There were no significant differences in preoperative visual analogue scale (VAS), knee society score (KSS), and range of motion (ROM) between the two groups. Lower VAS scores were found in the ERAS group at time of postoperative day (POD) 1 (P = 0.012) and POD 5 (P = 0.020); no significant differences were observed at time of postoperative month (POM) 1 and final follow-up. Higher KSS scores were found in the ERAS group at time of POD 1 (P = 0.013), and POD 5 (P = 0.011), no significant differences were observed at time of POM 1 and final follow-up. Increased ROM degree was found in the ERAS group at time of POD 1 (P = 0.021); no significant differences were observed at time of POD 5, POM 1 and final follow-up. Decreased intraoperative blood loss (P < 0.001), total blood loss (P < 0.001), transfusion rate (P = 0.004), and length of stay (P < 0.001) were found in the ERAS group; no significant differences were found in operative time and hospitalization costs between the two groups.

CONCLUSION

The ERAS program is safer and more efficacious in elderly TKA patients compared to the traditional pathway. It could effectively relieve perioperative pain and improve joint function, and reduce blood transfusion, length of stay, and total complications without increasing short-term mortality.

The role of prehabilitation with a telerehabilitation system prior to total knee arthroplasty

Background

The purpose of the current study was to evaluate the usage of prehabilitation on a telehealth platform prior to total knee arthroplasty (TKA) and its impact on short-term outcomes. Specifically, the study examined whether patients participating in a prehabilitation program impacted length of stay (LOS) and discharge disposition.

Methods

A total of 476 consecutive patients who underwent TKA at three institutions were included. The average age of the 476 patients was 65.1 years (range, 35 and 93 years). There was a total of 114 patients who utilized the novel prehabilitation program that provided exercises, nutritional advice, education regarding home safety and reducing medical risks, and pain management skills prior to surgery. A group of 362 patients who did not utilize the program formed the control cohort. The outcomes evaluated were LOS and discharge disposition to home, home with health aide (HHA), or skilled nursing facility (SNF).

Results

The average LOS in the prehabilitation group was significantly shorter than in the control group (2.0 vs. 2.7 days, P<0.001). Additionally, prehabilitation patients had more favorable discharge disposition status in comparison to the control group. In the prehabilitation patients, 77.2% went home without assistance, compared to 42.8% in the control group (P<0.001). Also, significantly fewer patients in the prehabilitation group were discharged to a SNF when compared to the control group (1.8% vs. 21.8%, P<0.0001).

Conclusions

Prehabilitation preceding TKA in the current study showed early benefits in LOS and discharge disposition. This study will help expand the current literature and educate orthopaedic surgeons on a novel technology. To truly appreciate the role of telerehabilitation in the setting of TKA, further investigation is needed to investigate long-term outcomes, cost analysis, and patient and clinician satisfaction.

VALIDATION AND CROSS-CULTURAL ADAPTATION OF RATING SYSTEMS WOMAC, KSS AND FJS-12 IN PATIENTS WITH KNEE DISORDERS AND INJURIES

The purposeof the work — is validation and cultural adaptation of the english-language rating systems for knee function assessment for use in scientific, medical and educational institutions of the Russian Federation.

Materials and Methods.The english versions of rating systems WOMac® 3.1 Index, The knee Society clinical Rating System©, FjS-12® were translated to Russian language by orthopedic surgeon with advanced level of english and the professional translator specializing in the translation of medical texts. Reverse translation was provided by third independent translator born in the english-speaking country (native speaker). a printed version of the various translations of the questionnaires was filled by patients with an interval of two days. The study group included 150 patients with Stage III knee osteoarthritis (90 women and 60 men aged 48 to 75 years, an average of 62.5 years) hospitalized in Vreden Research Institute of Traumatology and Orthopedics from February to april 2017 for total knee arthroplasty.

Results.good and very good retest reliability of WOMac (α = 0.87 and α = 0.9), kSS (α = 0.89 and α = 0.86) and FjS-12 (α = 0.94 and α = 0.96) was revealed. The study revealed a strong correlation between the results of the questionnaires performed by different translators: WOMac (Icc = 0.89), kSS (Icc = 0.86), FjS-12 (Icc = 0.92). The correlation dependence between subsections of WOMac (stiffness – Icc = 0.98, pain – Icc = 0.87, daily functions – Icc = 0.89) and kSS (knee score – Icc = 0.94, function score – Icc = 0.88), which indicates a good constructive validity.

Conclusion. The results of the study of criterial and constructive validity, as well as the retest reliability of the Russian versions of the WOMac, kSS and FjS-12 scales, indicate that they are a reliable and sensitive tool for assessing the function of knee joint, which can be widely used by Russian researchers in practical and scientific activities.

Painful Knee is not Uncommon after total Knee Arthroplasty and can be Treated by Arthroscopic Debridement

Background

After total knee arthroplasty (TKA), most patients have an improvement; however, a few continue to have residual pain. We reported a case series of painful knee after TKA with unreported reason.

Material and Methods

Forty-six arthroscopic surgeries were performed for painful knee after TKA. Of these, 16 were excluded due to infection, patellar clunk syndrome, patellofemoral synovial hyperplasia, aseptic loosening, or short follow up less than 6 months. Remaining 30 cases had marked tenderness at the medial and/or lateral tibiofemoral joint space, and they had pain during walking with pain or without pain at rest. The mean period from initial TKA to arthroscopy was 29 months, and the mean follow-up after arthroscopy was 36 months. All arthroscopic debridement was performed through 3 portals. Scar tissue impingements graded moderate or severe were found only in 30% of the cases in both the medial and lateral tibiofemoral joint spaces. The infrapatellar fat pad was covered with whitish scar tissue in all cases, and the tissue was connected with the scar tissue at the medial or lateral tibiofemoral joint spaces. All scar tissue was removed with a motorized shaver or punches.

Results

At the final follow-up, 63% were pain free, 3% had marked improvement, 20% had half improvement, 3% had slight improvement, and 11% had no change. We hypothesized that the lesser mobility of the scar tissue due to the continuity of the tissue between the infrapatellar fat pad and the tibiofemoral joint space could cause easy impingement at the tibiofemoral joint, even with the small volume of scar tissue.

Conclusion

If infection and aseptic loosening could be ruled out in a painful knee after TKA, arthroscopic debridement appeared to be a good option to resolve the pain.

What is the Responsiveness and Respondent Burden of the New Knee Society Score?

BACKGROUND

Although the new Knee Society score (NKSS) has been validated by a task force, a longitudinal study of the same cohort of patients to evaluate the score's responsiveness and respondent burden has not been reported, to our knowledge.

QUESTIONS/PURPOSES

We analyzed the NKSS for (1) responsiveness; (2) respondent burden; and (3) convergent validity in 148 patients studied longitudinally during more than 1 year.

METHODS

During an 8-month period, 165 patients underwent TKA by the same surgeon at our institution, of whom 148 (90%) completed this study; the others were excluded because of distance to travel or loss to followup at the specified time. The NKSS, WOMAC, and SF-12 were completed by each patient 1 day before surgery and at 3 and 12 months postoperatively. At the same times, the original KSS (OKSS) which is designed as an observer's assessment, was completed by the same orthopaedic fellow for all patients. Responsiveness of the NKSS was assessed by determining effect size, standardized response mean (SRM), and ceiling and floor effects. Respondent burden was assessed through time to completion recorded in minutes and ease of completion which was measured objectively on a Likert scale of 1 to 5 by the patients. Convergent validity was assessed by correlating the NKSS with the WOMAC, SF-12, and OKSS (current, widely used scales) by Pearson's correlation coefficient.

RESULTS

Effect size was largest (2.83 and 3.38) and SRM was highest (2.29 and 2.68) for the NKSS at 3 and 12 months respectively, indicating the NKSS to be the most-responsive score followed by the OKSS, WOMAC, and SF-12. The NKSS exhibited no ceiling and floor effects. The NKSS took a longer time to complete (5.49 ± 3.56 minutes) compared with the WOMAC (4.64 ± 3.19 minutes) and SF-12 (4.35 ± 3.27 minutes). The mean difference in time taken for the NKSS versus the WOMAC was 0.85 minutes (95% CI, 0.54-1.17 minutes; p < 0.001) and the mean difference for the NKSS versus the SF-12 was 1.14 minutes (95% CI, 0.76-1.15 minutes; p < 0.001). Its ease of completion generally was comparable to that of the WOMAC and SF-12. Convergent validity showed a strong correlation (r > 0.6; p < 0.001) of the NKSS with the WOMAC at all times and moderate to strong correlation (r = 0.4-0.6; p < 0.001) with the SF-12 and OKSS at the first two assessments, which became strong (r > 0.6; p < 0.001) at 12 months.

CONCLUSIONS

The NKSS exhibited greater responsiveness than the WOMAC, SF-12, and OKSS scales and showed no ceiling effect, indicating adequate potential for recording future improvement. The NKSS also showed reliable convergent validity when correlated with these other scores. However, it posed a greater respondent burden in terms of time to completion.

CLINICAL RELEVANCE

As independent nondevelopers of the NKSS, we found it to be a responsive tool for assessment of TKA outcomes. We have confirmed that the NKSS can be used interchangeably for this purpose with the WOMAC scale and that it correlates positively with other established scales of the SF-12 and OKSS. Further study of the short-form version will establish whether it also can be used effectively while reducing the respondent burden.

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.

Subjective evaluation before and after total knee arthroplasty using the 2011 Knee Society Score

BACKGROUND

Patient satisfaction has been recognized as an important evaluation of total knee arthroplasty (TKA). Therefore, the 2011 Knee Society Knee Scoring System (2011 KSS) was developed in order to quantify patient satisfaction, expectations, and physical activities following TKA. However, very few reports have described subjective evaluation before TKA using the 2011 KSS, as the scoring system is still relatively new. Therefore, the degree of improvement and change over time after TKA has not been evaluated.

METHODS

Forty-nine consecutive patients (79 knees) with a mean age of 74.8±7.3years were prospectively included in the study and evaluated preoperatively and one year postoperatively. The following questions were assessed using the 2011 KSS: (1) Do patient-derived clinical scores improve after TKA? (2) Do patient-derived clinical scores before TKA correlate with those after TKA? and (3) Are there correlations among each category of the 2011 KSS score?

RESULTS

The majority of categories showed significant improvements after TKA. The preoperative functional activities score was positively correlated with the postoperative symptoms, functional activities, and objective score. Each category of the 2011 KSS score correlated with others postoperatively.

CONCLUSIONS

All patient-derived scores except for patient expectation significantly improved postoperatively. The more functionally active patients before receiving TKA acquired more successful objective and functional outcomes, and the postoperative knee condition was directly influenced by each subscale of the 2011 KSS.

The Knee injury and Osteoarthritis Outcome Score reflects the severity of knee osteoarthritis better than the revised Knee Society Score in a general Japanese population

PURPOSE

The purposes of this study were to examine population-based reference data for sex- and age-related differences between the 2011 revised Knee Society Score (KSS2011) and the Knee injury and Osteoarthritis Outcome Score (KOOS), to assess the correlation between those scores and radiographic knee osteoarthritis (OA), and to validate the use of the scores in a general Japanese population.

METHODS

This cross-sectional study included 963 volunteers (368 males, 595 females; mean age: 54.7years). Participants were classified into five subgroups by age: under 40, 40s, 50s, 60s, and over 70years old. The KSS2011 and KOOS were determined using self-administered questionnaires. Weight-bearing radiographs of the bilateral knee were taken and graded according to the Kellgren-Lawrence (KL) scale. The mean KSS2011 and KOOS were compared among age groups. Correlations between the severity of knee OA and each score were assessed using multiple regression analysis.

RESULTS

The overall KSS2011 tended to gradually decrease with age. Most subscales of the KSS2011 did not show sex-related differences. Similarly, the overall KOOS and all its subscales steadily decreased by approximately 20 points per decade with age. Most subscales of the KOOS were significantly decreased in females over 50. The KL grade was significantly related to both the overall KOOS (β=-0.42, p<0.001) and KSS2011 (β=-0.13, p=0.001), though the correlation to the KOOS was stronger.

CONCLUSION

The overall KSS2011 and KOOS appear to decrease with age. In this population, the KOOS reflects the severity of knee OA better than the KSS2011.

The Knee Society Short Form Reduces Respondent Burden in the Assessment of Patient-reported Outcomes

BACKGROUND

The patient's own evaluation of function and satisfaction is a fundamental component of assessing outcomes after total knee arthroplasty (TKA). The new Knee Society Knee Score was introduced in 2012 and has been shown to be a valid and reliable instrument for measuring the outcome of TKA. This score combines an objective, physician-derived component and a patient-reported component to characterize the expectations, satisfaction, and functional activities of diverse lifestyles of contemporary patients undergoing TKA. However, in the routine clinical setting, the administration and scoring of outcome measures is often resource-intensive, as the expenditure of time and budget for outcome measurement increase with the length and complexity of the instrument used, and so a short-form assessment can help to reduce the burden the assessment of outcomes.

QUESTIONS/PURPOSES

The purposes of this study were (1) to develop a short-form version of the new Knee Society Knee Score; (2) to validate the short form against the full Knee Society Knee Score; and (3) to evaluate the responsiveness to treatment (TKA) of the new Knee Society short-form assessment.

METHODS

To develop the short form, data from the sample of 497 patients recruited during validation of the original long form the new Knee Society Knee Score were used. The multicenter study was approved by the institutional review boards at 15 participating medical institutions within the United States and Canada. An analytic item reduction approach was applied simultaneously but separately to preoperative and postoperative patient-reported data to select a subset of items from the original form that had good measurement properties and closely reflected the scores obtained using the original form.

RESULTS

Expectations and satisfaction were reflected by a single item in the newly developed short form compared with a total of five satisfaction and three expectation items in the long form. The functional activities subscale was reduced from 17 to six items. An excellent correlation was demonstrated between function scores derived from the functional activities subscale of the original long-form score (17 items) and the six-item short form (r = 0.97; p < 0.01). The sample mean difference between the two scores was less than 4 points with a SD of 6.7 points. The short form was capable of discriminating clinically different groups of patients before and after TKA with virtually the same estimated effect size as the original functional activities subscale of the new Knee Society Knee Score.

CONCLUSIONS

The Knee Society Knee Score long form is still recommended for research studies and for more sensitive measurement of the outcomes of individual patients. However, for general clinical use with large patient populations, the short form is expected to improve the rate of patient completion while also being easier to administer. In this study, we found the short-form version of the Knee Society Knee Score to be practical, valid, reliable, and responsive for assessing the functional outcome of TKA.

Patient-reported outcome measures after total knee arthroplasty: a systematic review

Objectives

A lack of connection between surgeons and patients in evaluating the outcome of total knee arthroplasty (TKA) has led to the search for the ideal patient-reported outcome measure (PROM) to evaluate these procedures. We hypothesised that the desired psychometric properties of the ideal outcome tool have not been uniformly addressed in studies describing TKA PROMS.

Methods

A systematic review was conducted investigating one or more facets of patient-reported scores for measuring primary TKA outcome. Studies were analysed by study design, subject demographics, surgical technique, and follow-up adequacy, with the ‘gold standard’ of psychometric properties being systematic development, validity, reliability, and responsiveness.

Results

A total of 38 articles reported outcomes from 47 different PROMS to 85 541 subjects at 26.3 months (standard deviation 30.8) post-operatively. Of the 38, eight developed new scores, 20 evaluated existing scores, and ten were cross-cultural adaptation of existing scores. Only six of 38 surveyed studies acknowledged all ‘gold standard’ psychometric properties. The most commonly studied PROMS were the Oxford Knee Score, New Knee Society Score, Osteoarthritis Outcome Score, and Western Ontario and McMaster Universities Osteoarthritis Index.

Conclusions

A single, validated, reliable, and responsive PROM addressing TKA patients’ priorities has not yet been identified. Moreover, a clear definition of a successful procedure remains elusive.

Cite this article: Bone Joint Res 2015;4:120–127

Measurement properties of the Brazilian Portuguese version of the MedRisk instrument for measuring patient satisfaction with physical therapy care

STUDY DESIGN

Clinical measurement study.

OBJECTIVES

To translate and cross-culturally adapt the MedRisk Instrument for Measuring Patient Satisfaction With Physical Therapy Care (MRPS) into Brazilian Portuguese and to test its measurement properties.

BACKGROUND

To date, there is no standardized instrument for measuring patient satisfaction with physical therapy care in Brazil.

METHODS

The MRPS was translated and cross-culturally adapted into Brazilian Portuguese. Patients completed the MRPS and a global change measure after 5 or more treatment visits. A subset of patients also completed the instrument a second time, 24 to 48 hours after the first assessment. We evaluated factorial validity, internal consistency, reproducibility, construct validity, and ceiling and floor effects.

RESULTS

Three hundred three patients with different musculoskeletal conditions receiving physical therapy care in Brazil participated in this study. A 3-factor solution labeled as interpersonal, convenience and efficiency, and patient education provided the best factor loadings. Cronbach alpha coefficients ranged from .63 to .77, intraclass correlation coefficients ranged from 0.64 to 0.79, and standard errors of measurement ranged from 0.86 to 1.75 points. Thirteen items of the MRPS were moderately correlated with the global measure of change. A large ceiling effect was detected.

CONCLUSION

Although we did not fully achieve the measurement properties suggested by the guidelines, we believe that the MRPS can be used among Brazilian Portuguese-speaking patients. Some differences with regard to factor structure of the Brazilian Portuguese MPRS compared with the English version were observed. The reason for this is likely a combination of cultural aspects, differences in clinical settings, and patient expectation.