Clinical diagnosis of symptomatic midfoot osteoarthritis:cross-sectional findings from the Clinical Assessment Study of the Foot

OBJECTIVE: To derive a multivariable diagnostic model for symptomatic midfoot osteoarthritis (OA). METHODS: Information on potential risk factors and clinical manifestations of symptomatic midfoot OA was collected using a health survey and standardised clinical examination of a population-based sample of 274 adults aged ≥50 years with midfoot pain. Following univariable analysis, random intercept multi-level logistic regression modelling that accounted for clustered data was used to identify the presence of midfoot OA independently scored on plain radiographs (dorso-plantar and lateral views), and defined as a score of ≥2 for osteophytes or joint space narrowing in at least one of four joints (first and second cuneometatarsal, navicular-first cuneiform and talonavicular joints). Model performance was summarised using the calibration slope and area under the curve (AUC). Internal validation and sensitivity analyses explored model over-fitting and certain assumptions. RESULTS: Compared to persons with midfoot pain only, symptomatic midfoot OA was associated with measures of static foot posture and range-of-motion at subtalar and ankle joints. Arch Index was the only retained clinical variable in a model containing age, gender and body mass index (BMI). The final model was poorly calibrated (calibration slope, 0.64, 95% CI: 0.39, 0.89) and discrimination was fair-to-poor (AUC, 0.64, 0.58, 0.70). Final model sensitivity and specificity were 29.9% (22.7, 38.0) and 87.5% (82.9, 91.3), respectively. Bootstrapping revealed the model to be over-optimistic and performance was not improved using continuous predictors. CONCLUSIONS: Brief clinical assessments provided only marginal information for identifying the presence of radiographic midfoot OA among community-dwelling persons with midfoot pain

Incidence and Progression of Hallux Valgus: A Prospective Cohort Study

OBJECTIVE: Hallux valgus is a common and disabling condition. The objective of this study was to identify factors associated with hallux valgus incidence and progression. METHODS: Participants were from a population-based prospective cohort study, the Clinical Assessment Study of the Foot. All adults aged =50 years registered with four general practices in North Staffordshire, UK were invited to take part in a postal survey at baseline and at 7-year follow-up which included health questionnaires and self-assessment of hallux valgus using line drawings. RESULTS: Complete baseline and follow-up data were available for 1,482 participants (739 women and 743 men, mean [standard deviation] age 62.9 [8.1] years), of whom 450 (30.4%) had hallux valgus in at least one foot at baseline. Incident hallux valgus was identified in 207 (20.1%) participants (349 [15.4%] feet) and was associated with baseline age, poorer physical health, foot pain and wearing shoes with a very narrow toe-box shape between the age of 20 and 29 years. Hallux valgus progression was identified in 497 (33.6%) participants (719 [24.3%] feet) but was not associated with any baseline factors. CONCLUSION: Incident hallux valgus develops in one in five adults aged =50 years over a 7-year period and is related to age, poorer physical health, foot pain and previous use of constrictive footwear. Progression occurs in one in three adults. These findings suggest that changes in first metatarsophalangeal joint alignment may still occur beyond the age of 50 years

Centre of pressure characteristics in normal, planus and cavus feet

Background The aim of this study was to compare centre of pressure (COP) characteristics between healthy adults with normal, planus or cavus feet who were allocated to groups based on reliable foot posture measurement techniques. Methods Ninety-two healthy adult participants (aged 18 to 45) were recruited and classified as either normal (n = 35), pes planus (n = 31) or pes cavus (n = 26) based on Foot Posture Index, Arch Index and normalised navicular height truncated measurements. Barefoot walking trials were conducted using an emed®-x 400 plantar pressure system (Novel GmbH, Munich, Germany). Average, maximum, minimum and range (difference between maximum and minimum) values were calculated for COP velocity and lateral-medial force index during loading response, midstance, terminal stance and pre-swing phases of stance. The COP excursion index was also calculated. One-way analyses of variance were used to compare the three foot posture groups. Results The cavus foot exhibited the slowest average and minimum COP velocity during terminal stance, but this pattern was reversed during pre-swing, when the cavus foot exhibited the fastest maximum COP velocity. The planus foot exhibited the smallest lateral medial force index range during terminal stance. There were no differences between the groups for COP excursion index. Conclusion These findings indicate that there are differences in COP characteristics between foot postures, which may represent different mechanisms for generating force to facilitate forward progression of the body during the propulsive phases of gait

Plantar pressures in people with midfoot osteoarthritis: cross-sectional findings from the Clinical Assessment Study of the Foot

Background Midfoot osteoarthritis (OA) is a common condition, however its aetiology is not well understood. Understanding how plantar pressures differ between people with and without midfoot OA may provide insight into the aetiology and how best to manage this condition. Research question To compare plantar pressures between people with and without symptomatic radiographic midfoot OA. Methods This was a cross-sectional study of adults aged ≥50 years registered with four UK general practices who reported foot pain in the past year. Symptomatic radiographic midfoot OA was defined as midfoot pain in the last four weeks, combined with radiographic OA in one or more midfoot joints. Cases were matched 1:1 for sex and age (± 5 years) to asymptomatic controls. Peak plantar pressure and maximum force in 10 regions of the foot were determined using a pressure platform (RSscan International, Olen, Belgium) and compared between the groups using independent samples t-tests and effect sizes (Cohen’s d). Results We included 61 midfoot OA cases (mean age 67.0, SD 8.1, 31 males, 30 females) and matched these to 61 controls (mean age 66.0, SD 7.9). Midfoot OA cases displayed greater force (d=0.79, medium effect size, p=<0.001) and pressure at the midfoot (d=0.70, medium effect size, p=<0.001), greater force at the fourth metatarsophalangeal (MTP) joint (d=0.28, small effect size, p=0.13), and fifth MTP joint (d=0.37, small effect size, p=0.10) and greater pressure at the fifth MTP joint (d=0.34, small effect size, p=0.13). They also displayed lower force (d=0.40, small effect size, p=0.02) and pressure at the hallux (d=0.50, medium effect size, p=<0.001) and lower force (d=0.54, medium effect size, p=<0.001) and pressure at the lesser toes (d=0.48, small effect size, p=<0.001) compared with controls. Significance Midfoot OA appears associated with lowering of the medial longitudinal arch, greater lateral push off and less propulsion at toe off. Longitudinal studies are needed to establish causal relationships

Structural foot characteristics in people with midfoot osteoarthritis: Cross‐Sectional findings from the clinical assessment study of the foot

Objective: This study compared radiographic measures of foot structure between people with and without symptomatic radiographic midfoot osteoarthritis (OA). Methods: This was a cross‐sectional study of adults aged 50 years and older registered with four UK general practices who reported foot pain in the past year. Bilateral weightbearing dorsoplantar and lateral radiographs were obtained. Symptomatic radiographic midfoot OA was defined as midfoot pain in the last 4 weeks, combined with radiographic OA in one or more midfoot joints (first cuneometatarsal, second cuneometatarsal, navicular‐first cuneiform, and talonavicular). Midfoot OA cases were matched 1:1 for sex and age to controls with a 5‐year age tolerance. Eleven radiographic measures were extracted and compared between the groups using independent sample t‐tests and effect sizes (Cohen's d). Results: We identified 63 midfoot OA cases (mean ± SD age was 66.8 ± 8.0 years, with 32 male and 31 female participants) and matched these to 63 controls (mean ± SD age was 65.9 ± 7.8 years). There were no differences in metatarsal lengths between the groups. However, those with midfoot OA had a higher calcaneal‐first metatarsal angle (d = 0.43, small effect size, P = 0.018) and lower calcaneal inclination angle (d = 0.46, small effect size, P = 0.011) compared with controls. Conclusions: People with midfoot OA have a flatter foot posture compared with controls. Although caution is required when inferring causation from cross‐sectional data, these findings are consistent with a pathomechanical pathway linking foot structure to the development of midfoot OA. Prospective studies are required to determine the temporal relationships between foot structure, function, and the development of this common and disabling condition

Identifying Long-Term Trajectories of Foot Pain Severity and Potential Prognostic Factors: A Population-Based Cohort Study.

ObjectivesTo identify distinct foot pain trajectories over 7 years and examine their associations with potential prognostic factors.MethodsAdults ages ≥50 years and registered with 4 general practices in North Staffordshire, UK were mailed a baseline health survey. Those reporting current or recent foot pain were invited to attend a research assessment clinic. Follow-up was by repeated postal surveys at 18, 36, 54, and 84 months. Distinct trajectories of foot pain were explored using latent class growth analysis (LCGA). Subsequently, identified trajectories were combined into most and least progressive groups, and covariate-adjusted associations with a range of prognostic factors were examined.ResultsOf 560 adults with foot pain attending baseline research clinics, 425 (76%) provided data at baseline and 2 or more follow-up time points. LCGA for foot pain severity (0-10 numerical rating scale) identified a 4-trajectory model: "mild, improving" (37%); "moderate, improving" (33%); "moderate-severe, persistent" (24%); and "severe, persistent" (6%). Compared with individuals in more favorable (improving) pain trajectories, those in less favorable (persistent) pain trajectories were more likely to be obese, have routine/manual and intermediate occupations, have poorer physical and mental health, have catastrophizing beliefs, have greater foot-specific functional limitation, and have self-assessed hallux valgus at baseline.ConclusionsFour distinct trajectories of foot pain were identified over a 7-year period, with one-third of individuals classified as having pain that is persistently moderate-severe and severe in intensity. The effect of intervening to target modifiable prognostic factors such as obesity and hallux valgus on long-term outcomes in people with foot pain requires investigation