Radiographic validation of a self-report instrument for hallux valgus.

BACKGROUND: Hallux valgus (HV) is a common condition causing substantial morbidity. Radiographic assessment is the gold standard for grading severity but is not always feasible in clinical/research settings. HV line-drawings, consisting of five drawings for each foot depicting a sequential increase in HV angle of 15°, have been clinically validated for self-reporting severity. We aimed to undertake radiographic validation of this self-report instrument. METHODS: Adults aged ≥50 from four GP practices were sent a health survey. Responders self-reported HV severity for each foot using the line-drawing instrument. Those reporting foot pain in the last year had radiographs taken at a research clinic from which intermetatarsal, hallux abductus and hallux interphalangeal abductus angles were calculated. Ten feet were randomly selected for each HV line-drawing grade for both feet. Associations between self-reported HV line drawings and radiographic measurements were assessed using Spearman's ρ correlation coefficients, mean radiographic angle measurement (95% confidence interval) and one-way analysis of variance. RESULTS: Increasing HV line-drawing grade was positively correlated with radiographic measurements for intermetatarsal and hallux abductus angles (Spearman's ρ = 0.602, p < 0.001; 0.821, p < 0.001, respectively). Hallux interphalangeal abductus angle showed an inverse correlation with increasing line-drawing grade (-0.204, p = 0.053). Differences in radiographic measures between HV line drawing grades were significant for intermetatarsal (F = 13.98, p < 0.001) hallux abductus (F = 38.90, p < 0.001) but not hallux interphalangeal abductus angle (F = 2.21, p = 0.075). CONCLUSION: Grading HV severity by self-reported HV line-drawings provides a valid representation of deformity determined from radiographic measurements and is a useful screening/self-reporting tool.

Identification of patterns of foot and ankle pain in the community: Cross-sectional findings from the clinical assessment study of the foot.

OBJECTIVES: To investigate patterns of foot and ankle pain locations and symptoms, socio-demographic and comorbid characteristics to examine whether there are distinct foot and ankle pain phenotypes. METHODS: Adults aged ≥50 years registered with four general practices in North Staffordshire were mailed a Health Survey questionnaire. Participants reporting foot pain in the last month indicated foot pain location on a foot manikin. Foot and ankle pain patterns were investigated by latent class analysis. Associations between the classes with foot pain symptoms, socio-demographic and comorbid characteristics were assessed. RESULTS: Four thousand four hundred fifty-five participants with complete foot pain and manikin data were included in this analysis (mean age 65 years [SD 9.8], 49% male). Of those with foot and ankle pain (n = 1356), 90% had pain in more than one region. Six distinct classes of foot and ankle pain were identified: no pain (71%), bilateral forefoot/midfoot pain (4%), bilateral hindfoot pain (5%), left forefoot/midfoot pain (8%), right forefoot/midfoot pain (5%) and bilateral widespread foot and ankle pain (6%). People with bilateral widespread foot and ankle pain were more likely to be female, obese, depressed, anxious, have/had a manual occupation, have comorbidities, lower SF-12 scores and greater foot-specific disability. Age did not differ between classes. CONCLUSIONS: Six distinct classes of foot and ankle pain locations were identified, and those with bilateral widespread foot and ankle pain had distinct characteristics. Further investigation of these individuals is required to determine if they have poorer outcomes over time and whether they would benefit from earlier identification and treatment.