Age- and Sex-Related Normative Data for the Foot Function Index in a German-Speaking Cohort

Foot and Ankle Outcome Score (FAOS): Reference Values From a National Representative Sample

Background

The Foot and Ankle Outcome Score (FAOS) is widely used in clinical practice and research. However, FAOS reference values are missing to aid interpretation. This study aimed to establish national record-based reference values for the FAOS.

Methods

A national representative sample of 9996 adult Danish citizens was derived from the Danish Civil Registration System. The FAOS questionnaire was sent to all participants, including 2 supplemental questions regarding previous foot and ankle problems and body mass index (BMI). A threshold of 10 FAOS points was predefined as a clinically relevant difference across all 5 subscales.

Results

A total of 2759 participants completed the FAOS. Mean age of participants was 60.5 years, and 51% were women. The mean FAOS subscale scores were as follows: pain, 87.1 (95% CI 86.4-87.8); symptoms, 85.1 (95% CI 84.5-85.8); activity of daily living (ADL), 88.9 (95% CI 88.2-89.6); sport and recreation function 78.5 (95% CI 77.4-79.6); and quality of life (QOL), 79.9 (95% CI 79.0-80.9). The mean difference between men and women was small and not clinically relevant (ranged from 0.9 in ADL to 3.4 in QOL). The largest differences in mean scores between age groups ranged from 4.3 in symptoms to 16.4 in sport/rec. Except for the subscale sport/rec, all age-related differences were below the predefined threshold of 10 for clinical relevance. The difference in mean subscale scores between the lowest BMI group (<24.7) and the obese group (>30) ranged from 19.6 in ADL to 39.1 in sport/rec.

Conclusion

We found in our population that BMI severely impacted FAOS scores. We recommend using BMI-specific reference FAOS values. Separate FAOS reference values for men and women appear not needed. Stratifying reference values for age is likely not needed except for the subscale sport and recreation function.

Level of evidence

Level III, cohort study.

Quality of life in children with preaxial polydactyly of the foot in comparison to adults, postaxial polydactyly and healthy controls

The effect of preaxial polydactyly of the foot on health-related quality of life (HR-QoL) has not been investigated in current literature. To improve counseling, we investigated HR-QoL in this patient group. A patient-control study was performed with children with preaxial polydactyly ( n  = 20), adults with preaxial polydactyly ( n  = 15), children with postaxial polydactyly ( n  = 15) and healthy controls ( n  = 62). The primary outcome was the difference in the foot-specific quality of life (FS-QoL) between children with preaxial polydactyly and adults with preaxial polydactyly, children with postaxial polydactyly and controls, using the Oxford Ankle and Foot Questionnaire (OxAFQ-c) and five foot-specific visual analogue scales (VAS). The secondary outcome was the difference in general HR-QoL, using the Pediatric Quality of Life Inventory (PedsQL). Outcomes were compared with the Mann-Whitney-U test. Comparison between children with preaxial polydactyly and healthy controls and postaxial polydactyly showed worse outcomes in all OxAFQ-c domains. The foot-specific VAS score was significantly worse in children with preaxial polydactyly compared to postaxial polydactyly and controls. Only the PedsQL physical domain showed a lower outcome in children with preaxial polydactyly than in postaxial polydactyly and controls. Children and adults with preaxial polydactyly scored the same in all domains. The OxAFQ-c and the PedsQL physical domain showed significantly worse outcomes in children with preaxial polydactyly compared with healthy controls and postaxial polydactyly. However, large variation was observed, suggesting large differences between patients. In children and adults, the foot and scar appearance seems to be the biggest problem, while diminished foot function seems less of an issue.

Patient Reported Outcome Measures in the Foot and Ankle: Normative Values Do Not Reflect 100% Full Function

PURPOSE

The primary purpose of this study was to determine normative values for foot and ankle ability measure (FAAM), activities of daily living (ADL), FAAM/foot and ankle disability (FADI) Sport, Tegner activity scale, SF-12 physical component summary (PCS) and mental component summary (MCS) in individuals who are representative of the "normal" adult population in the United States. The secondary purpose was to perform a confirmatory factor analysis (CFA) of ankle functional ability to provide evidence of reliability and validity of commonly used orthopaedic outcome scores. Our hypothesis was that normative values will differ based on patient characteristics and demographics, and that the selected commonly used foot and ankle outcomes scores will demonstrate acceptable reliability and validity estimates.

METHODS

There were 271 persons in this study (101 women, 170 men, average age = 31.4 (SD = 15.1) years, average BMI = 25.9 (SD = 5.9)). Age, sex and BMI were documented. Comparisons of outcome scores were made between cohorts. CFA was performed to test factor structure of ankle functional ability.

RESULTS

There was no significant difference in FAAM ADL between women and men (n.s.) or FAAM Sport (n.s.). Women had significantly higher SF-12 PCS (P = 0.001). Men had significantly higher SF-12 MCS (P < 0.001) and Tegner (P = 0.024). FAAM ADL, FAAM Sport and SF-12 PCS scores were significantly higher in people who did not have previous ankle surgery. Younger people and those with lower BMI had significantly higher ankle function. Reliability was excellent, and the CFA had excellent model fit demonstrating evidence of validity.

CONCLUSIONS

This study revealed that normative values of foot and ankle outcome measures did not reflect 100% function and differed by sex, previous ankle surgery status, age and BMI. Individuals who did not have previous ankle surgery were younger, and had lower BMI and higher functional levels. Reliability was excellent, and the CFA model demonstrated excellent fit, providing evidence for validity, and lending support to use aggregated outcome measures as one scale. This study is unique in that it provides surgeons with normative ankle values in commonly reported outcome measures including the FAAM, FADI SF-12 and Tegner activity scale, in the normal population, based on BMI, age, gender and previous ankle surgery status. This information can be a very useful tool in the clinical setting for patient expectations counseling. In addition, surgeons and clinicians can feel confident using these outcome scores to assess their patients' progress through the continuum of care.

LEVEL OF EVIDENCE

Level II.

Normative data for the Patient-Rated Wrist Evaluation questionnaire

STUDY DESIGN

Cross-sectional study.

INTRODUCTION

The Patient-Rated Wrist Evaluation (PRWE) questionnaire is used to evaluate functional outcomes after treatment of wrist and hand injuries and nontraumatic conditions. Since patients commonly present with an injury, it is impossible to assess preinjury physical functioning. Therefore, it is important to be aware of the population-based normative data.

PURPOSE OF THE STUDY

The aim of this study was to determine the normative data for the PRWE questionnaire. Secondary, we aimed to determine if there were factors influencing these normative data.

METHODS

Visitors and employees of 4 hospitals were requested to participate. Excluded were all participants who were scheduled for surgery or were in treatment or after treatment for an injury of the wrist or hand within 1 year after trauma. All participants were asked to complete the PRWE questionnaire and were asked for their age, sex, history of wrist or hand fracture or surgery, daily activities, and the type of employment. The socioeconomic status was determined based on the zip code.

RESULTS

The median PRWE score was 0 (interquartile range: 0-8.5) and the mean score 7.7 (standard deviation: 15.0). Women had significantly higher scores compared to men, and younger individuals had significantly lower scores. Participants with a history of wrist or hand fracture or surgery, and participants who were unfit for work had significantly higher scores. Socioeconomic status was not correlated with the PRWE score.

DISCUSSION

The purpose was to provide an representative overview of the normative data for the normal population. We did not want to present the data of an unnatural healthy population, which is not representative of the normal population. Deleting patients with chronic wrist or hand complaints, would have resulted in normative values which are not representable for the normal, average population.

CONCLUSION

Low scores are observed for the PRWE in the general population. These scores are age and sex dependent and are higher in individuals with a history of wrist or hand fracture or surgery or who are unfit for work.

Measurement properties of PROMIS short forms for pain and function in orthopedic foot and ankle surgery patients

PURPOSE

To examine the measurement properties of the German PROMIS short forms for pain intensity (PAIN), pain interference (PI) and physical function (PF) in orthopedic foot and ankle surgery patients.

METHODS

Patient-rated outcomes were collected from consecutive patients of our foot and ankle registry before and 6 months after surgery. Measurement properties were tested according to the COnsensus-based Standards for the selection of health status Measurement Instruments (COSMIN). The German Foot Function Index (FFI-D) served as a legacy measure.

RESULTS

748 patients were included in our cross-sectional sample. Longitudinal and test-retest data were available for 202 and 65 patients, respectively. Construct validity of all short forms was good. All Cronbach's α and intraclass correlation coefficients were > 0.7. The smallest detectable change (SDC) was highest for PF (8.9) and lowest for PI (6.5). Minimal important change was 4 to 5 points and thus smaller than SDC for all instruments. We observed a baseline ceiling effect for PF. PI showed insufficiently correlated change scores with FFI-D disability change scores, and therefore failed the responsiveness testing.

CONCLUSION

Our study showed some adequate psychometric properties, but also certain aspects regarding interpretability and responsiveness that researchers must be aware of when using PROMIS short forms of pain and function in foot and ankle surgery patients.

Age- and Gender-Specific Normative Values for the Self-Reported Foot and Ankle Score (SEFAS)

BACKGROUND

The Self-Reported Foot and Ankle Score (SEFAS) is a foot- and ankle-specific patient-reported outcome measurement (PROM) score that has been validated with good results for a variety of foot and ankle disorders. SEFAS is sensitive detecting improvement or deterioration after surgery. However, normative values, required to put a specific patient's summary score into perspective, are lacking.

METHODS

In this report, we included 396 population-based men and 383 women (43% of the invited individuals), age 20-89 years, who had completed the SEFAS questionnaire and questions regarding anthropometrics and health. We used Mann-Whitney U test to test gender differences and Spearman correlation coefficients to determine any association between SEFAS score and age. We present gender-specific median SEFAS scores with range and 5th to 95th percentiles and mean with standard deviation.

RESULTS

The SEFAS normative values were median 48 in men (range 11-48), 5th to 95th percentiles 31 to 48 and mean 45 ± 6, and in women, median 47 (range 6-48), 5th to 95th percentiles 23 to 48 and mean 43 ± 8 (gender comparison P < .001). SEFAS normative values correlated inversely with age (r = -0.12, P < .001).

CONCLUSION

In the general population, older age was associated with lower SEFAS value, and men had higher values than women. The population-based normative SEFAS values provided in this study can facilitate quantification of disability related to foot and ankle with and without surgery in the foot and ankle.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Treatment of Bone Marrow Edema of the Foot and Ankle With the Prostacyclin Analog Iloprost

BACKGROUND

Bone marrow edema (BME) of the foot and ankle is challenging to treat. One approach is intravenous Iloprost treatment, which is a vasoactive prostacyclin analog. The aim of this study was to evaluate the early and intermediate outcome of intravenous Iloprost therapy on BME of the foot and ankle and to analyze the influence of its etiology and Association Research Circulation Osseous (ARCO) stage on the outcome.

METHODS

This was a retrospective study with prospective follow-up. All patients treated by intravenous Iloprost for BME of the foot and ankle (ARCO I-III) at a single orthopedic reference center were included. Demographics, medical history, and MRIs were assessed prior to treatment (t0). MRIs were used to assess the BMEs' etiology (idiopathic/ischemic/metabolic, mechanical/degenerative, traumatic) and severity (ARCO). Complications as well as changes in pain, treatment, and MRI were evaluated after 3 months (t1). The following patient-rated outcome measures (PROMs) were assessed prospectively (t2): 12-Item Short Form Health Survey (SF-12), Visual Analog Scale Foot and Ankle (VAS FA), and the Foot Function Index (FFI) (also at t0). The descriptive outcomes and the influence of the etiology and ARCO on the outcome parameters were evaluated. Out of 70 eligible patients, 42 patients (60%; 47 ± 15 years; 30% female) with a mean follow-up of 28 ± 19 months were included.

RESULTS

Twelve patients reported minor complications during Iloprost therapy. At t1, pain decreased significantly in 56%, and the amount of BME decreased in 83% of patients. Both parameters correlated moderately (r = -0.463, P = .015). The PROMs at t2 revealed moderate results. The overall FFI improved from 59 ± 21 to 30 ± 22 ( P < .001), the overall VAS FA was 68 ± 20, the SF-12 Physical Component Summary 42 ± 12 and Mental Component Summary 50 ± 9. Subgroup analysis revealed no significant influence of the etiology or ARCO stage on any outcome measure.

CONCLUSION

Iloprost therapy for BME of the foot and ankle resulted in a 60% pain and 80% edema decrease after 3 months. After 2 years, patient-rated outcome measures showed residual impairment. Neither the etiology nor ARCO stage significantly influenced the outcome.

LEVEL OF EVIDENCE

Level III, comparative study.

Outcome following osteosynthesis or primary arthrodesis of calcaneal fractures: A cross-sectional cohort study

BACKGROUND

Calcaneal fractures are uncommon and have a substantial impact on hindfoot function and quality of life. Several surgical treatment options are available; both in surgical approach and type of operation. The aim of this study was to compare functional outcome and quality of life following ORIF and primary arthrodesis. Furthermore, predictors of worse functional outcome were explored.

METHODS

A retrospective cross-sectional cohort study was performed in patients with surgical fixation of a calcaneal fracture with a minimum follow-up of 18 months. Patients received ORIF through the 1) Extended Lateral Approach (ELA), 2) Sinus Tarsi Approach (STA) or 3) primary arthrodesis via STA. Participants were presented a questionnaire containing demographics, the AOFAS hindfoot scale, Foot Function Index, SF-36, EQ-5D and patient satisfaction.

RESULTS

In total 95 patients participated in this study. The three groups were comparable regarding patient characteristics. A median score of 74.5 points on the AOFAS hindfoot scale and 11.9 on the FFI was found for the entire group. There were no statistically significant differences between patients with ORIF of primary arthrodesis. Patients scored a median of 49.0 on the Physical Component Scale of the SF-36 and 55.4 on the Mental Component Scale. On the EQ-5D patients scored a median of 0.8 points. Again no statistically significant differences were observed between the three subgroups. Socio-economic status was the only statistically significant predictor of worse functional outcome (β: 4.06, 95% CI: 0.50-7.62) after multivariable analysis.

INTERPRETATION

Good midterm outcomes following in terms of functional outcome and in quality of life are observed. We observed no statistical significant difference in functional outcome between patients with ORIF and patients with primary arthrodesis. The only predictor of worse functional outcome is a lower socio-economic status.

Normative data for the lower extremity functional scale (LEFS)

Background and purpose - The lower extremity functional scale (LEFS) is a well-known and validated instrument for measurement of lower extremity function. The LEFS was developed in a group of patients with various musculoskeletal disorders, and no reference data for the healthy population are available. Here we provide normative data for the LEFS. Methods - Healthy visitors and staff at 4 hospitals were requested to participate. A minimum of 250 volunteers had to be included at each hospital. Participants were excluded if they had undergone lower extremity surgery within 1 year of filling out the questionnaire, or were scheduled for lower extremity surgery. Normative values for the LEFS for the population as a whole were calculated. Furthermore, the influence of sex, age, type of employment, socioeconomic status, and history of lower extremity surgery on the LEFS were investigated. Results - 1,014 individuals fulfilled the inclusion criteria and were included in the study. The median score for the LEFS for the whole population was 77 (out of a maximum of 80). Men and women had similar median scores (78 and 76, respectively), and younger individuals had better scores. Participants who were unfit for work had worse scores. There were no statistically significant correlations between socioeconomic status and type of employment on the one hand and LEFS score on the other. A history of lower extremity surgery was associated with a lower LEFS score. Interpretation - High scores were observed for the LEFS throughout the whole population, although they did decrease with age. Men had a slightly higher score than women. There was no statistically significant correlation between socioeconomic status and LEFS score, but people who were unfit for work had a significantly worse LEFS score.

Validity and reliability of the Foot Function Index (FFI) questionnaire Brazilian-Portuguese version

PURPOSE

To evaluate the validity and reliability of the Foot Function Index (FFI) in its Brazilian Portuguese version.

METHODS

The validity and reliability of the FFI were tested in 50 volunteers, with plantar fasciitis, metatarsalgia and chronic ankle sprain. The FFI validity process used the Short Form-36 (SF-36) and Foot and Ankle Outcome Score (FAOS) questionnaires. The correlation between FFI, SF-36 and FAOS was done using the Pearson's linear coefficient. The inter and intra-evaluator reliability was ascertained by means of the intraclass correlation coefficient (ICC) and the internal consistency by means of Cronbach's alpha coefficient. The scores were used to assess the standard error measurement (SEM), minimal detectable change (MDC) and ceiling floor and effects.

RESULTS

The validity process showed that there were correlations between FFI and the "pain" and "social aspects" subscales of SF-36 and all subscales of FAOS, except for "other symptoms". The Brazilian-Portuguese version of FFI showed excellent intra and interevaluator correlations, with an ICC range of 0.99-0.97 and score reliability that was considered highly satisfactory, with Cronbach's alpha range of 0.80-0.61. The SEMs for inter and intra-evaluator reliability were 1.32 and 1.08, respectively. The MDC was 2.42 (90 % confidence interval). No ceiling and floor effect were detected.

CONCLUSIONS

The Brazilian-Portuguese version of the FFI questionnaire was found to be a valid and reliable instrument for foot function evaluation, and can be used both in scientific settings and in clinical practice.