The validity and reliability of the modified forgotten joint score

The Joint Awareness Score: A Shortened, Simplified, Improved Alternative to the Forgotten Joint Score

Background

The Forgotten Joint Score (FJS) is a 12-question patient-reported outcomes measure created to measure a patient's awareness of their artificial joint. The FJS has attained wide usage, though it is not without weaknesses. Our patients report that the semantics of the English translation are flawed and that the 5 answer options for each question are poorly differentiated. Additionally, the FJS will result in no score if 3 or more questions are unanswered. This prompted the development of an alternative patient-reported outcomes measure, the Joint Awareness Score (JAS), that builds upon the core concept of joint awareness underlying the FJS, but that is easier to understand and shorter to complete. We completed an exploratory, pilot study to evaluate this outcomes instrument. Our hypothesis is that the JAS will correlate strongly with the FJS and could be used as a substitute.

Methods

Knee arthroplasty patients in a prospective registry were administered the FJS and the JAS. Internal consistency and correlation were calculated with Cronbach's alpha and Pearson's correlation coefficient, respectively.

Results

This study included 174 patients. Cronbach's alpha for FJS was 0.97 for 6 months and 0.97 for 12 months, whereas JAS was 0.89 at 6 months and 0.85 at 12 months. Pearson correlation comparing FJS and JAS at 6 months was 0.88 (95% confidence interval: 0.83, 0.92) and 0.86 (95% confidence interval: 0.78, 0.92) at 12 months.

Conclusions

The Joint Awareness Score is a new patient-reported outcomes measure that is a substitute for the FJS, with half the number of questions, improved semantics, and simplified answers.

Metabolic equivalent of task scores avoid the ceiling effect observed with conventional patient-reported outcome scores following knee arthroplasty

The metabolic equivalent of task (MET) score examines patient performance in relation to energy expenditure before and after knee arthroplasty. This study assesses its use in a knee arthroplasty population in comparison with the widely used Oxford Knee Score (OKS) and EuroQol five-dimension index (EQ-5D), which are reported to be limited by ceiling effects. A total of 116 patients with OKS, EQ-5D, and MET scores before, and at least six months following, unilateral primary knee arthroplasty were identified from a database. Procedures were performed by a single surgeon between 2014 and 2019 consecutively. Scores were analyzed for normality, skewness, kurtosis, and the presence of ceiling/floor effects. Concurrent validity between the MET score, OKS, and EQ-5D was assessed using Spearman's rank. Postoperatively the OKS and EQ-5D demonstrated negative skews in distribution, with high kurtosis at six months and one year. The OKS demonstrated a ceiling effect at one year (15.7%) postoperatively. The EQ-5D demonstrated a ceiling effect at six months (30.2%) and one year (39.8%) postoperatively. The MET score did not demonstrate a skewed distribution or ceiling effect either at six months or one year postoperatively. Weak-moderate correlations were noted between the MET score and conventional scores at six months and one year postoperatively. In contrast to the OKS and EQ-5D, the MET score was normally distributed postoperatively with no ceiling effect. It is worth consideration as an arthroplasty outcome measure, particularly for patients with high expectations.

Multiple Imputation to Salvage Partial Respondents: Analysis of the Forgotten Joint Score-12 After Total Hip Arthroplasty

BACKGROUND

Missing responses are common when Asian patients complete the Forgotten Joint Score-12 (FJS-12), which is widely used to evaluate total hip arthroplasty (THA). We aimed to provide orthopaedic researchers with a solution for handling missing values in such patient-reported outcome measures (PROMs).

METHODS

Patients who had undergone primary THA between 1998 and 2016 (n = 1,021) were investigated in 2020. The FJS-12 and 9 other PROMs, including questions related to Asian lifestyle activities, were administered. Risk factors for missing FJS-12 items were investigated. Partial respondents were matched with complete respondents; then, in each pair, the items not completed by the partial respondent were deleted from the responses of the complete respondent. Predictive mean matching (PMM) was performed in an attempt to recover the deleted items, using 65 sets of imputation models. After the missing values had been imputed, we explored patient characteristics that affected the FJS-12, using data from all complete and partial respondents.

RESULTS

A total of 652 patients responded to the survey (393 complete and 193 partial respondents). Partial respondents were older, more often female, and less active. Older respondents were more likely to skip items involving the bed, while those who reported a better ability to sit in the seiza style (traditional Japanese floor sitting) were more likely to skip items about chair sitting. The imputed FJS-12 value exhibited excellent reliability (intraclass correlation coefficient for agreement with the true scores, 0.985). FJS-12 values of complete respondents were significantly higher than those of respondents with 4 to 11 missing items (51.6 versus 32.8, p < 0.001). Older age was associated with higher FJS-12 values, which was revealed only via analysis of the multiply imputed data sets (p < 0.001).

CONCLUSIONS

Analysis of only complete FJS-12 responses after THA resulted in a nonresponse bias, preferentially excluding older, female, and less active individuals and those with a traditional floor living style. Multiple imputation could provide a solution to scoring and analyzing PROMs with missing responses by permitting the inclusion of partial respondents.

LEVEL OF EVIDENCE

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

Clinical outcomes after using patient specific instrumentation: is it worth the effort? A minimum 5-year retrospective review of 298 PSI knees

INTRODUCTION

Use of patient specific instrumentation (PSI) for performing total knee arthroplasty (TKA) has been shown to improve component positioning but there is dearth of evidence regarding clinical outcomes. The aim of our study was to report patient satisfaction and functional outcome scores of patients who underwent PSI TKAs at minimum 5 year follow up.

METHODS

This is a retrospective study of a prospectively collected data of patients who underwent PSI TKAs between January 2012 and October 2015 under a single surgeon. Patient Reported Outcome Measures (PROMs), patient satisfaction questionnaires, surgeon directed 3D planning changes and intra-operative changes were collected and analysed.

RESULTS

The cohort included 298 consecutive PSI TKAs performed on 249 patients at a mean age of 71 years (range: 49-93 years). On an average 4 changes were made for each knee during 3D planning compared to preliminary plan. Intra-operative implant size change was required only in 3% (10 knees). The PROM scores were collected at a mean follow-up period of 6.8 years (range: 5.0-8.6 years) for 224 knees. Oxford Knee Score improved from median pre-operative score of 18 (IQR: 13-24) to median post-operative score of 44 (IQR: 40-47) with a median gain of 23 (IQR: 16-30). The median modified Forgotten Joint Score was 87.5 (IQR: 54.4-98.1). For the Beverland questionnaire, 75% (n = 166) reported being "Very Happy" and only 4% (n = 9/222) were 'Never Happy'.

CONCLUSION

Excellent patient satisfaction and functional scores at mid-term can be achieve d using PSI technique to perform TKA with careful surgeon directed pre-operative planning.

Validation of Single-Outcome Questionnaire in Primary TKA and THA

BACKGROUND

Patient-reported outcome measures can be used to evaluate post-operative health care quality and patient satisfaction. The Patient's Joint Perception (PJP) question gathers a single patient-reported outcome to measure how patients appraise their joint. This study compares PJP to the Forgotten Joint Score (FJS) at 21 months post-operation to assess its value.

METHODS

A retrospective review was performed at an orthopedic specialty hospital for patients who completed both PJP and FJS questionnaires in 2020-2021 and underwent either a unilateral elective primary Total Knee Arthroplasty (TKA) or Total Hip Arthroplasty (THA). Spearman's correlation coefficients and P-values were calculated to determine external validity of PJP. Floor and ceiling effects were analyzed and considered present if ≥ 15% of patients achieved the worst or best score (0-4 for PJP and 0-100 for FJS).

RESULTS

In total, 534 patients (327 THA and 207 TKA) were surveyed at 21 months post-operation. External validity against FJS was assessed for both TKA (r = 0.66, P < .01) and THA (r = 0.69, P < .01). For TKA, the floor and ceiling effects were 0.97% and 25.12% for PJP and 3.86% and 4.83% for FJS, respectively. For THA, the floor and ceiling effects were 0.92% and 50.46% for PJP and 2.47% and 20.50% for FJS, respectively.

CONCLUSION

The PJP was correlated with FJS moderately for both TKA and THA and can be collected with lesser burden. However, ceiling effects were higher in both TKA and THA for PJP compared to FJS. Further studies are needed to investigate the questionnaires at additional time points and to evaluate the implications of high ceiling effects.

Are there functional biomechanical differences in robotic arm-assisted bi-unicompartmental knee arthroplasty compared with conventional total knee arthroplasty? A prospective, randomized controlled trial

AIMS

The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery.

METHODS

A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model.

RESULTS

Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R² = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial axial alignment (R² = 0.352; p = 0.029), and TKA femoral sagittal alignment (R² = 0.252; p = 0.016). The bi-UKA group showed a significant increased ability in the proprioceptive joint position test, but no difference was found in more dynamic testing of proprioception.

CONCLUSION

Robotic arm-assisted bi-UKA demonstrated equivalence to TKA in achieving a biphasic gait pattern after surgery for osteoarthritis of the knee. Both treatments are successful at improving gait, but both leave the patients with a functional limitation that is not present in healthy age-matched controls. Cite this article: Bone Joint J 2022;103-B(4):433-443.

No difference between resurfaced and non-resurfaced patellae with a modern prosthesis design: a prospective randomized study of 250 total knee arthroplasties

PURPOSE

Despite numerous well-conducted studies and meta-analyses, the management of the patella during total knee arthroplasty (TKA) remains controversial. The aim of our study was to compare the clinical and radiological outcomes between patients with and without patellar resurfacing and to determine the influence of resurfacing on patellar tracking with a "patella-friendly" prosthesis.

METHODS

A single-centered prospective randomized controlled study was performed between April 2017 and November 2018. Two hundred and forty-five consecutive patients (250 knees) scheduled for TKA were randomized for patellar resurfacing or patella non-resurfacing. All patients received the same total knee prosthesis and were evaluated clinically and radiologically, including the International Knee Society Score (KSS knee and function), Forgotten Joint Score (FJS), anterior knee pain (AKP), pain when climbing stairs, patellar tilt, and patellar translation.

RESULTS

Two hundred and twenty-nine knees were available for clinical evaluation and 221 knees for radiographic analysis. The revision rate for patellofemoral cause was 3.1% (7 cases) with no difference between the groups (p = 0.217). There was no difference in survival rate between patellar resurfacing (88.3%) and non-resurfacing (85.3%) after 24 months (p = 0.599). There were no differences in KSS functional component (p = 0.599), KSS knee component (p = 0.396), FJS (p = 0.798), and AKP (p = 0.688) at a mean follow-up of 18 months. There was twice as much stair pain for the non-resurfacing group (17.1% versus 8.5%) (p = 0.043). There was patellar tilt in 43% of resurfaced knees (n = 50/116) versus 29% in non-resurfaced knees (n = 30/105) (p = 0.025); however, there was more patellar translation in the non-resurfaced group (21.0% versus 7.8%) (p < 0.001). There were no specific complications attributed to the patellar resurfacing procedure. There were four secondary patellar resurfacing procedures (3.6%) in the non-resurfaced group after a mean of 10 ± 7 months (1-17) postoperatively.

CONCLUSION

There is no superiority of patellar resurfacing or non-resurfacing in terms of clinical or radiological outcomes at mid-term. Secondary patellar resurfacing is rare. There is not enough evidence to recommend systematic patellar resurfacing with a "patella-friendly" prosthesis.

Short-Term Outcomes of Robotic Lateral Unicompartmental Knee Arthroplasty: An Indian Perspective

BACKGROUND

Lateral UKA is a technically more challenging procedure than medial UKA accounting for < 1% of all knee arthroplasties. Robotic UKA for lateral compartment arthritis is rare and has not been reported in India.

MATERIALS AND METHODS

This is a prospective single-centre clinical study of six patients (five females and one male) who underwent robotic-arm-assisted lateral UKA (RALUKA) between May 2018 and January 2020 with patient-specific 3D-CT preoperative plan. Overall satisfaction on a five-level Likert scale, clinical outcome based on the KOOS and MFJS and radiological outcomes based on the HKA axis, femorotibial angle (FTA), tibial posterior slope (PS) obtained were compared preoperatively and postoperatively.

RESULTS

At a mean follow-up period of 23.84 months, among six patients 33.3% very satisfied, 50% satisfied and 16.7% felt neutral. The mean KOOS changed from 63.03 ± 3.52 to 93.95 ± 3.25 and the mean MFJS was 75.41 ± 10.29 postoperatively. The mean HKA axis changed from 175.81° ± 2.88 valgus to 179.99° ± 2.14 neutral alignment. The mean correction attained was from 4.19° ± 2.88 valgus deformity to 0.01° ± 2.14. The mean FTA and the mean PS changed from 7.34° ± 4.14 of valgus to 1.92° ± 1.85 of valgus and 83.44° ± 1.77 to 85.38° ± 2.10, respectively.

CONCLUSIONS

The mean preoperative and postoperative KOOS showed a statistical significance with a p value of < 0.001 (< 0.05), showing significant improvement with RALUKA. RALUKA is a promising surgical option for lateral compartment OA of the knee.

Normative FJS-12 scores for the knee in an Asian population: a cross-sectional study

Background

The Forgotten Joint Score is a patient-reported outcome measure validated in assessing patients post knee arthroplasty, anterior cruciate ligament (ACL) reconstruction surgery and patellar dislocation. A previous study had established the normative scores of a population in the USA but included knees with pathology. The aim of our study is to obtain normative Forgotten Joint Scores in young Asian adults without any pre-existing knee pathologies to increase the interpretability of the Forgotten Joint Score-12 (FJS-12) score.

Methods

We conducted a cross-sectional study across young healthy Asian adults via electronic platforms. Participants who had sought either Western medical consultation, physiotherapy or traditional medical therapies were excluded. Demographic data, occupation, type of sport played, and FJS-12 scores were collected. Scores were stratified into subgroups and analysed.

Results

There were 172 participants who met our inclusion criteria for this study. The average age of participants in our study was 28.1 ± 10.5 years (range 14–70 years), with 83 (47.7%) participants falling into the ages 21–25 years. Average body mass index (BMI) was 21.9 ± 3.3 kg/m² (range 14.7–36.3 kg/m²). The average FJS-12 score was 62.8 ± 25.6. The median FJS-12 was 63.5 with a range of 4.2–100. Nine participants (5.2%) scored the maximum score possible, and 56 (32.6%) participants scored below the midpoint score of 50. The percentiles for each subgroup of participants were tabulated and reported. Notably, males aged 46–70 years old scored the highest average FJS-12 score of 73.4 ± 5.5, and females aged 31–45 years old scored the lowest FJS-12 score of 57.1 ± 25.1. Females scored lower than males, although the difference was not statistically significant (p = 0.157). There were no significant correlations between BMI, age, or type of sport played with FJS-12; however, interestingly, we observed that women reported similar FJS-12 scores across all age groups, while men reported better scores with increasing age.Interestingly, we observed that women reported similar FJS-12 scores across all age groups, while men reported better scores with increasing age. 

Conclusion

Having normative values provides opportunities for benchmarking and comparing individuals against age- and gender-matched peers in the general population. Knowledge of normative values for FJS-12 scores would aid evaluating and tracking progress in patients recovering from injuries or undergoing post-surgery rehabilitation. This would help clinicians  determine if they return to ‘normal’ post intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43019-021-00122-2.

Early outcomes after robotic arm-assisted bi-unicompartmental knee arthroplasty compared with total knee arthroplasty: a prospective, randomized controlled trial

AIMS

The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively.

METHODS

A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status.

RESULTS

Both operations were shown to offer comparable outcomes, with no significant differences between the groups across all timepoints and outcome measures. Both groups also had similarly low rates of complications. Subgroup analysis for preoperative psychological state, activity levels, and BMI showed no difference in outcomes between the two groups.

CONCLUSION

Robotic arm-assisted, cruciate-sparing bi-UKA offered similar early clinical outcomes and rates of complications to a mechanically aligned TKA, both in the immediate postoperative period and up to one year following surgery. Further work is required to identify which patients with osteoarthritis of the knee will derive benefit from a cruciate-sparing bi-UKA. Cite this article: Bone Joint J 2021;103-B(10):1561-1570.

Forgotten Joint Score Post Total Knee Arthroplasty and Its Correlation with the New Knee Society Score

BACKGROUND/PURPOSE

Forgotten Joint Score (FJS) is designed to asses patient recovery post Total Knee Arthroplasty (TKA) in a new dimension. It assess the ability to forget the operated joint as artificial during activities of daily living. New Knee Society Score (NKSS) is developed to encompass objective and subjective outcome as well as an assessment of patient expectation and satisfaction. Our purpose was (1) to determine FJS at 1 year post TKA in Indian Patients, and (2) to assess convergent validity between FJS and the NKSS. We hypothesised that FJS should strongly correlate with the Satisfaction (SS) and Knee perception(KPS) sub-component of NKSS.

METHODS

We enrolled 181 patients who underwent primary TKA during an 8-month duration. They were prospectively followed up at 1-year review clinic when FJS and NKSS were administered. 169 patients completed the assessment forms and 13 patients were lost to follow-up. Statistical evaluation was done with Spearman correlation test.

RESULTS

Mean FJS at 1 year was 66.6 ± 25.9 with 14% ceiling and 1% floor effects. There was a mild to moderate correlation of FJS with NKSS (p < 0.001, r = 0.47) and its sub-scores (p < 0.001; r = 0.43 and r = 0.44). There was a weak correlation of FJS with NKSS sub-components of SS and KPS (p < 0.001; r = 0.37 and 0.25, respectively).

CONCLUSION

Mean FJS at 1 year post TKA showed convergent validity with NKSS; however, the correlation was not strong enough to use them interchangeably. Hypothesis that FJS should strongly correlate with the NKSS sub-components of satisfaction and joint perception was refuted. We conclude, FJS provides unique evaluation in recovery post TKA, different from NKSS.

LEVEL OF EVIDENCE

Level III.

Disappointing Relationship between Functional Performance and Patient Satisfaction of UKA Patients: A Cross Sectional Study

BACKGROUND

Following a Unicompartmental knee arthroplasty (UKA) satisfaction is often conflated with functional outcome. Recent studies have shown that satisfaction is not linked to functional outcome. The research questions were: (1) what is the relationship between satisfaction and functional performance and quality of life (absolute and gain values) after UKA? And (2) what is the level of satisfaction, function, and quality of life after UKA?

HYPOTHESIS

There is a poor relationship between functional performance and patient satisfaction following UKA.

METHODS

This was a retrospective study using a locally held arthroplasty register to identify patients who had undergone UKA between 2004 and 2017. Patient reported outcome measures (PROMs) were collected prospectively and included EQ-5D, Oxford Knee Score (OKS) and satisfaction score (based on a visual analogue score with 0 being worst and 100 being best). Patients with a complete set of pre-operative and 2-year post-operative outcome scores were included. Patients who subsequently underwent revision surgery were excluded. 1638 patients were identified, of which 896 were eligible for inclusion. The average age was 66.7 years old, with 46.3% of patients being female.

RESULTS

There was a moderate to strong correlation between the absolute or relative values for OKS and the patient satisfaction following UKA (r=0.705 and r=0.522, respectively). The average pre-operative scores improved from a median of 23 (IQR 18-28) to 43 (IQR 35-46) (p<0.001) and from a median of 0.62 (IQR 0.186-0.691) to 0.85 (IQR 0.691 - 1) (p<0.001) for OKS and EQ-5D, respectively. In terms of satisfaction with outcome, 82.6% of patients were very satisfied and 4.4% were dissatisfied (scoring ≥80% and <50%, respectively). At 2 years, the PASS was met or surpassed by 73.1% and 54.9% (OKS and EQ-5D, respectively). The MCID was met or surpassed by 93% and 78% (OKS and EQ-5D, respectively).

DISCUSSION/CONCLUSION

UKA is a successful procedure generating high levels of patient function and satisfaction. Because patients' OKS and EQ-5D scores may be influenced by comorbidities, those scores are of disappointing predictive value in estimating patient satisfaction, and therefore should not be used as a surrogate to determine the success of the UKA procedure.

LEVEL OF EVIDENCE

III; Restrospective cohort study.

A bicentric approach evaluating the combination of a hemispheric cup with a novel ceramic head in total hip arthroplasty

Medical ceramics are frequently used biomaterials as a liner in total hip arthroplasty. Strong efforts have been made to improve material properties over the last decades. Alumina toughened zirconia ceramics seem to be promising alternatives to further reduce fracture rates and squeaking phenomena. To answer the question if alumina toughened zirconia ceramic liners in combination with a cementless, hemispheric cup are able to reduce squeaking phenomena and fracture rates, we initiated a bicentric, mid-term trial. Noise phenomena will be recorded using MONA Score (Melbourne Orthopaedic Noise Assessment). Functional outcome (Harris Hip Score, University of California-Los Angeles, Forgotten Joint Score, EQ-5D Score, Visual Analogue Scale) and radiographic parameters will serve as secondary parameters. The study has been set up for 5 years, with follow-ups after 6-14 weeks, 12, 24 and 60 months.

A long-term cross-sectional study with modified forgotten joint score to assess the perception of artificial joint after total knee arthroplasty

BACKGROUND AND PURPOSE

The ultimate goal for an arthroplasty surgeon is to provide the patient a joint that feels more like a natural joint. The Modified Forgotten Joint Score (MFJS) is a newly introduced functional scoring system that has a superior ability to assess this property among arthroplasty patients. The objective of this study is to evaluate the long-term temporal association of the MFJS and total knee arthroplasty (TKA).

METHODS

We assessed 360 patients post TKA with MFJS questionnaire. The patient groups were distributed at follow-up intervals of 3 weeks (n = 55), 6 months (n = 45), 1 year (n = 57), 2 years (n = 40), 3 years (n = 49), 5 years (n = 49), 7 years (n = 39), and 10 years (n = 26). Higher score suggests a forgotten artificial joint.

RESULTS

Post-operative mean MFJS scores were 64.4 ± 7.6 at 3 weeks, 87.7 ± 5.6 at 6 months, 89.2 ± 3.1 at 1 year, 89.9 ± 2.6 at 2 years, 89.4 ± 3.2 at 3 years, 89.1 ± 4 at 5 years, 84.5 ± 8.8 at 7 years, and 82.7 ± 11.9 at 10 years. The score at 3 weeks was significantly lesser than the average scores at other follow-up intervals. The score at 6 months was significantly higher compared to the score at 10 years. The average score at 1 year, 2 years, 3 years, and 5 years were significantly higher compared to the average score at 7 years and 10 years.

CONCLUSION

The trend of the MFJS score was found to drastically improve from 3 weeks to 6 months and peak in 2 years after which the score tends to attain a plateau up to 5 years following which there is a decline in the score at 7- and 10-years post-surgery. Age did not have an influence on the variation in functional score in any of the follow-up groups. MFJS has a strong positive correlation with the well-recognised KOOS scoring system.

LEVEL OF EVIDENCE

IV.

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.

The Forgotten Joint Score-12 in Anterior Cruciate Ligament injuries

PURPOSE

The Forgotten Joint Score (FJS-12) is a scoring system initially created to assess post arthroplasty outcomes. It has since been used to evaluate Anterior Cruciate Ligament surgery outcomes. Our study aims to evaluate the applicability and validity of the FJS-12 in post Anterior Cruciate Ligament reconstructed patients, and to assess correlation with established Patient Reported Outcome Measure Scores in the same population.

DESIGN

Case series, level 3 evidence.

METHODS

We conducted a cross sectional study across patients who had undergone Anterior Cruciate Ligament reconstruction and carried out the FJS-12 questionnaire by phone interview. Patients who had undergone primary Anterior Cruciate Ligament reconstruction were considered for the study.

RESULTS

The average Forgotten Joint Score-12 for all 82 patients was 71.4 (±22.9), which corresponded to a normal distribution. The average Lysholm and Tegner score at the 2-year post-operative visit was 93.5 ± 9.5 and 5.8 ± 1.8 respectively and the distribution was non-normal. We noticed a large ceiling effect of 42.7% in the Lysholm scores, but only 8.4% in FJS-12. There was a weak correlation with Lysholm and a positive correlation with Tegner.

CONCLUSIONS

Forgotten Joint Score-12 seems to be a promising patient reported outcome measure that can be used in evaluating post Anterior Cruciate Ligament reconstruction outcomes. It is more discerning than traditional scores and is easy to administer thus it can used in the clinical follow-up of patients. With the scores being normally distributed, it makes for a meaningful PROMS and would allow more accurate application of parametric statistical tests.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Does the medial pivot knee improve the clinical and radiographic outcome of total knee arthroplasty? A single centre study on two hundred and ninety seven patients

PURPOSE

Total knee arthroplasty (TKA) is a cost-effective surgery with a survival rate higher than 90% after 15 years. Nevertheless, patients are unsatisfied in more than 15% of cases. Medial pivot (MP) prosthetic designs were introduced in late 90's with the aim to reproduce natural knee kinematics. The purpose of this study is to evaluate the survivorship and clinical outcomes of a novel design of MP knee with a minimum follow-up of five years.

METHODS

This is a retrospective review of all patients who underwent primary TKA using the K-Mod dynamic congruence implant (Gruppo Bioimpianti, Peschiera Borromeo, Milan, Italy) between 2012 and 2013 at a single institution. A total of 339 patients (351 knees) were included with a mean age of 74 years (range 41-89). The Knee Society score, the global range of movement, the Western Ontario and McMaster Universities Osteoarthritis score, Forgotten Joint score, and the short-term form 12 health survey were collected. FJS and SF-12 were collected only post-operatively. Radiographic outcomes were evaluated according to the Knee Society's roentgenographic evaluation system. Kaplan-Meyer (KM) curves were performed to evaluate implant survivorship. A two-tailed paired t test was performed to evaluate the differences between pre-operative and post-operative score.

RESULTS

A total 297 patients (315 knees) were available for clinical and radiographic analysis, and the mean follow-up was 66.4 months. A total of 17 patients (17 knees 5.4%) experienced a post-operative complication, and a reoperation was performed in five patients (5 knees 1.6%). Four patients had a periprosthetic joint infection, and two patients had a post-traumatic periprosthetic femoral fracture. The KM survivorship at five years was 98.2% (95% CI 0.96 to 0.99) for revision for any reason. There was a statistically significant improvement (p < 0.05) in all the objective and subjective outcomes measured.

CONCLUSION

The K-Mod dynamic congruence design has shown an excellent clinical, radiographic, and patient-reported outcome in primary TKAs.

The Forgotten Joint Score-12 in Swedish patients undergoing knee arthroplasty: a validation study with the Knee Injury and Osteoarthritis Outcome Score (KOOS) as comparator

Background and purpose - Having patients self-evaluate the outcome is an important part of the follow-up after knee arthroplasty. The Forgotten Joint Score-12 (FJS-12) introduced joint awareness as a new approach, suggested to be sensitive enough to differentiate well-functioning patients. This study evaluated the Swedish translation of the FJS-12 and investigated the validity, reliability, and interpretability in patients undergoing knee arthroplastyPatients and methods - We included 109 consecutive patients 1 year after primary knee arthroplasty to assess construct validity (Pearson's correlation coefficient, r), internal consistency (Cronbach's alpha [CA]), floor and ceiling effects, and score distribution. The Knee injury and Osteoarthritis Outcome Score (KOOS) was the comparator instrument for the analyses. Further, 31 patients preoperatively and 22 patients postoperatively were included to assess test-retest reliability (intraclass correlation coefficient [ICC]).Results - Construct validity was moderate to excellent (r = 0.62-0.84). The FJS-12 showed a high degree of internal consistency (CA = 0.96). The ICC was good preoperatively (0.76) and postoperatively (0.87). Ceiling effects were 2.8% in the FJS-12 and ranging between 0.9% and 10% in the KOOS.Interpretation - The Swedish translation of the FJS-12 showed good validity and reliability and can be used to assess outcome after knee arthroplasty. Moreover, the FJS-12 shows promising results in its ability to differentiate well-functioning patients. Future studies on unidimensionality, scale validity, interpretability, and responsiveness are needed for a more explicit analysis of the psychometric properties.