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

Low Ceiling Effects of the Forgotten Joint Score Compared With Legacy Measures After Joint-Preserving Procedures: A Systematic Review

PURPOSE

To determine, in patients undergoing joint preservation procedures, whether the Forgotten Joint Score (FJS) compares favorably with legacy measures.

METHODS

Medical databases (including PubMed/MEDLINE and Embase databases) were queried for publications with the terms "Forgotten Joint Score" and "hip," "knee," "arthroscopy," or "ACL." Fourteen studies met the inclusion criteria. Methodologic quality was assessed through the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist, and psychometric data were evaluated for ceiling or floor effects, convergent validity, internal consistency, reliability, responsiveness, measurement invariance, and measurement error by 2 fellowship-trained orthopaedic surgeons (B.D.K. and W.T.H.).

RESULTS

Data were collected from 14 studies using the FJS after joint-preserving procedures in 911 patients (959 joints). Four studies reported strong internal consistency with an average Cronbach α of 0.92. Two studies reported responsiveness with an effect size ranging from 0.6 to 1.16. One study reported reproducibility with an interclass correlation coefficient of 0.9 (95% confidence interval, 0.8-0.9). One study reported measurement error with an minimum detectable change (MDC)individual of 32% and MDCgroup of 4.5%. Studies reported moderate to very strong convergent validity across legacy measures for hip and knee preservation surgery. Ceiling effects were favorable compared with many legacy scores for hip and knee preservation. Three studies reported the minimal clinically important difference whereas 1 study reported the patient acceptable symptomatic state for the FJS.

CONCLUSIONS

The FJS is a methodologically sound outcome measure used to evaluate patient outcomes after hip and knee preservation surgery with overall low ceiling effects compared with legacy measures.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Good Validity and High Internal Consistency of the Forgotten Joint Score-12 in Patients After Medial Opening Wedge High Tibial Osteotomy

BACKGROUND

The Forgotten Joint Score-12 (FJS-12) was originally developed to assess awareness of an artificial joint. Medial opening wedge high tibial osteotomy (MOWHTO), an alternative surgical method of knee replacement, is a joint-preservation surgery; therefore, joint awareness should be used to evaluate its clinical results. However, FJS-12 has not been validated as a tool to evaluate the postoperative results of MOWHTO. This study aimed to validate FJS-12 in MOWHTO.

METHODS

Patients with bilateral knee surgery, previous knee surgery, flexion contracture >15°, varus alignment >20°, and patients without plate removal surgery were excluded. Finally, 71 knees of 71 patients were analyzed, with a mean follow-up of 34.5 months. The FJS-12 score and Knee Injury and Osteoarthritis Outcome Score (KOOS) were obtained, and the floor and ceiling effect of each score was investigated. Cronbach's α was calculated to determine the internal consistency of FJS-12. Spearman's correlation coefficients between FJS-12 and KOOS were calculated to assess convergent validity.

RESULTS

There were ceiling effects in 3 KOOS subscales (symptoms [25.4%], pain [15.5%], and activities of daily living [25.4%]) but not in FJS-12 (8.5%). No floor effect was noted in any patient-reported outcome measures. The total Cronbach's α was 0.9457 in FJS-12. FJS-12 showed moderate-to-strong positive correlations with all KOOS subscales (r = 0.64-0.72).

CONCLUSION

FJS-12 showed a lower ceiling effect than KOOS and high internal consistency and convergent validity in patients following MOWHTO. With its low ceiling effect, FJS-12 was found to be useful for evaluating patients following MOWHTO.

Evaluation of joint awareness after acetabular fracture: Validation of the Forgotten Joint Score according to the COSMIN checklist protocol

BACKGROUND

A fracture of the acetabulum is an uncommon, but serious injury. Established outcome tools do not reflect the patient’s perspective after fracture of the hip joint. Originally designed for post-arthroplasty patients, the Forgotten Joint Score (FJS) is a patient-reported outcome measurement (PROM) tool evaluating the disease-specific health-related quality of life (HR-QoL).

AIM

To validate the FJS in patients after acetabular fracture.

METHODS

In a prospective mono-centric cohort study, we evaluated 100 patients at mean 5.2 ± 3.6 years after a fracture of the acetabulum. The validation study followed the complete COSMIN checklist protocol. For calculation of convergent validity, we used the Tegner-Activity Scale, the Western Ontario and McMaster Universities Osteoarthritis Index, the EuroQol-5D, and a subjective rating of change as an anchor variable.

RESULTS

We confirmed good internal consistency with a Cronbach‘s alpha of 0.95. With an intraclass correlation coefficient of 0.99 (95%CI: 0.97, 0.99), test-retest reliability of the FJS was excellent. Correlation coefficients between the questionnaires were moderate to high ranging from |0.56| to |0.83| (absolute value). No relevant floor or ceiling effects occurred. Standard error of measurement was 3.2 and smallest detectable change (SDC) was 8.8. Thus, changes greater than 8.8 points between two assessments denote a real change in FJS.

CONCLUSION

The FJS is a valid and reliable tool for evaluation of patient-reported outcome in posttraumatic condition after acetabular fracture. The SDC indicating a real clinical improvement was 8.8 points in the FJS. We could confirm responsiveness of the FJS and found no relevant floor- or ceiling effects.

Patient-reported outcomes of 7133 distal femoral, patellar, and proximal tibial fracture patients: A national cross-sectional study with one-, three-, and five-year follow-up

BACKGROUND

Few studies have described patient-reported outcome measures (PROMs) in knee fracture patients. We reported knee-specific and generic median PROM scores after knee fracture and identified risk factors for poor outcome defined by low median PROM scores.

METHODS

In a Danish cross-sectional study of 7133 distal femoral, patellar, and proximal tibial fracture patients during 2011-2017, OKS, FJS-12, EQ5D-5L Index, and EQ5D-5L Visual Analogue Scale (VAS), were collected electronically (response rate 53%; median age 60; 63% female). Poor outcome was defined as score lower than median PROM score. Poor outcome risk factors were estimated as odds ratios from binary logistic regression models.

RESULTS

At 0 to one year after knee fracture, median PROM scores were 31 (OKS), 27 (FJS-12), 0.50 (EQ5D-5L Index), and 74 (EQ5D-5L VAS). At >5 years after knee fracture, median OKS score was 40, median FJS-12 score was 54, median EQ5D-5L Index was 0.76, and median EQ5D-5L VAS score was 80. Age > 40 years had higher odds for poor OKS and FJS-12 scores at short- and long-term follow-up after knee fracture. Comorbidity burden, distal femoral fracture, and treatment with external fixation and knee arthroplasty were risk factors for poor outcome at long-term follow-up, for all four PROMs.

CONCLUSIONS

Although knee fracture patients have relatively high knee function and quality of life, their ability to forget about the knee joint after knee fracture is compromised. We identified several important risk factors for poor outcome measured by PROMs at different follow-up periods following knee fracture, which will help direct future quality-improvement initiatives.

Differences in case mix and outcomes between Swiss and Scottish total knee arthroplasty patients

PURPOSE

The clinical benefits of total knee arthroplasty (TKA) are well defined, but little attention has been paid to the cross-cultural variation. The objective of this study was to compare case mix and outcomes following TKA in Swiss and Scottish patients.

METHODS

Data from local registries at a Swiss and a Scottish orthopaedic hospital were extracted to evaluate: (A) age, sex, body mass index (BMI), self-reported health status (EQ-5D), and joint awareness (Forgotten Joint Score-12 (FJS-12)) at pre-surgery, (B) improvement in EQ-5D and FJS-12 scores from pre-surgery to 1 year, and (C) patient satisfaction at 1 year.

RESULTS

Data from 2075 Swiss and 994 Scottish TKA patients were available from the local registries. Swiss and Scottish patients differed in age (69.3 vs 68.8 years, p = 0.046), sex ratio (62.9% vs 56.9% women, p = 0.002) and BMI (29.6 vs 30.9, p < 0.001). At pre-surgery, FJS-12 scores were comparable (Swiss 12.1 vs Scottish 10.9, n.s.), but EQ-5D scores were better in Swiss patients (0.52 vs 0.40, p < 0.001). Post-operative improvement was greater in Switzerland for the FJS-12 (+ 55.1 vs + 32.2, p < 0.001), but not for the EQ-5D (+ 0.31 vs + 0.29, n.s.). The satisfaction rate was similar in both groups (88.3% vs 89.6%, n.s.).

CONCLUSION

Subtle cross-cultural variation was evident in TKA case-mix factors between the two countries. Satisfaction and improvement in health status were similar, while improvement in joint-specific outcome was notably greater in Switzerland. Understanding cross-cultural variability of the outcome has important implications when interpreting study and registry data from other countries and when counselling a patient in daily practice.

LEVEL OF EVIDENCE

Retrospective cohort, Level III.

Normative Values for the Forgotten Joint Score-12 for the US General Population

BACKGROUND

The Forgotten Joint Score-12 (FJS-12) is a patient-reported outcome questionnaire of joint awareness in patients with hip and knee pathologies. To improve interpretability of values derived from this measure, we collected normative values for the US general population.

METHODS

A sample of 2000 participants, representative of US general population, was sought via an online panel. Quota sampling was used to obtain age-specific and sex-specific groups of 200 participants each. The FJS-12 is a 12-item questionnaire assessing the ability to forget the hip or knee joint during activities of daily living. To match US national census data from 2010, raking was used for determining data weights.

RESULTS

Normative data for the FJS-12 could be established based on a data set from 2017 respondents (50.1% men; mean age, 54.0 years; 66.3% white/Caucasian). Median FJS-12 scores in the total sample were 75.0 points for knees and 87.5 points for hips. In the age-specific and sex-specific groups, the lowest median score for knees was 54.2 points (men aged 18-39 years) and the highest median was 97.0 (men aged above 70 years). Similarly, median scores for hips were lowest in men aged 18-39 years (60.9 points) and highest in men aged above 70 years (100 points).

CONCLUSION

Normative values have been established for the FJS-12 for hips and knees in US general population. Age-specific and sex-specific differences require relying on normative values from the respective groups when interpreting FJS-12 data.

Duration of incapacity of work after tibial plateau fracture is affected by work intensity

BACKGROUND

Tibial plateau fractures requiring surgery are severe injuries of the lower extremity. Tibial plateau fractures have an impact not only on physically demanding jobs but notably on general professional life too. The aim of this study was to assess how the professional activity of patients will be affected after a tibial plateau fracture.

METHODS

39 consecutive patients (ages 20-61 years) were retrospectively included in the study and were clinically examined at a minimum of 14 month postoperatively. Inclusion criteria were surgical treatment of tibial plateau fractures between November 2009 and December 2012. The clinical evaluation included the Lysholm score and the Oxford Knee Score. Fractures were classified and analyzed using the AO classification. Intensity of work was classified as established by the REFA Association. The patients themselves provided postoperative duration of the incapacity of work and subjective ratings.

RESULTS

17 (43.6%) women and 22 (56.4%) men were examined with a mean follow-up of 29.7 ± 10.4 months (range 14-47). According to the AO classification there were 20 (51.3%) B-type-fractures and 19 (48.7%) C-type-fractures. The median incapacity of work was 120 days (range 10-700 days) with no significant differences between B- and C-type-fractures. Four (10.3%) patients reduced their working hours by 10.5 h per week on average. Patients with low workload (REFA 0-1, median incapacity of work 90 days, range 10-390 days) had a significant shorter incapacity of work than patients with heavy workload (REFA 2-4, median incapacity of work 180 days, range 90-700 days) (p < 0.05). The median Lysholm score decreased significantly from 100 points (range 69-100) before the injury to 73 points (range 23-100) at the time of the follow-up. All patients received postoperative physiotherapy (median 25 appointments, range 6-330), with a significant higher number of appointments for C-type-fractures than for B-type-fractures (p = 0.004).

CONCLUSION

A relationship was found between workload and the duration of incapacity of work after tibial plateau fractures. The post-injury shift to less demanding jobs and the reduction of working hours highlight the impact of a tibial plateau fracture on a patient's subsequent physical ability to work.