Midfoot osteoarthritis: potential phenotypes and their associations with demographic, symptomatic and clinical characteristics

Abstract

s u m m a r yObjective: To investigate the demographic, symptomatic, clinical and structural foot characteristics associated with potential phenotypes of midfoot osteoarthritis (OA). Design: Cross-sectional study of 533 community-dwelling adults aged !50 years with foot pain in the past year. Health questionnaires and clinical assessments of symptoms, foot structure and function were undertaken. Potential midfoot OA phenotypes were defined by the pattern of radiographic joint involvement affecting either the medial midfoot (talonavicular, navicular-1 st cuneiform, or cuneiform-1 st metatarsal joint), central midfoot (2 nd cuneiform-metatarsal joint), or both medial and central midfoot joints. Multivariable regression models with generalised estimating equations were used to investigate the associations between patterns of midfoot joint involvement and symptomatic, clinical and structural characteristics compared to those with no or minimal midfoot OA. Results: Of 879 eligible feet, 168 had medial midfoot OA, 103 central midfoot OA, 76 both medial and central midfoot OA and 532 no/minimal OA. Having both medial and central midfoot OA was associated with higher pain scores, dorsally-located midfoot pain (OR 2.54, 95%CI 1.45, 4.45), hallux valgus (OR 1.76, 95%CI 1.02, 3.05), flatter foot posture (b 0.44, 95%CI 0.12, 0.77), lower medial arch height (b 0.02, 95%CI 0.01, 0.03) and less subtalar inversion and 1 st MTPJ dorsiflexion. Isolated medial midfoot OA and central midfoot OA had few distinguishing clinical characteristics. Conclusions: Distinct phenotypes of midfoot OA appear challenging to identify, with substantial overlap in symptoms and clinical characteristics. Phenotypic differences in symptoms, foot posture and function were apparent in this study only when both the medial and central midfoot were involved.

Foot structure and lower limb function in individuals with midfoot osteoarthritis: a systematic review

“…Of these 16 potentially eligible articles, two were conference proceedings 26,27 , one was ineligible based on study design 25 and one was ineligible based on the outcome measure used 10 . Of the 12 articles, six additional data requests were required, of these there were two requests for additional data 20,28 , and five required transformation of data into appropriate format for comparison 9,14,20,23,29 . Of the six data requests, three were received 9,14,29 .…”

“…A wide range of outcomes were measured relating to foot structure and lower limb function. To simplify reporting of these variables, five categories were created: (1) clinical measures of foot structure, alignment or range of motion (three studies 9,14,29 ), (2) radiographic measures of foot structure or alignment (four studies 13,20e22 ), (3) lower limb kinematics and kinetics during walking (two studies 23,24 ), (4) plantar pressures during walking (two studies 8,13 ), and (5) lower limb muscle activation during walking (one study 24 ). The outcome measures were selected before reviewing the articles and the categories were created after reviewing the articles to simplify reporting of these variables.…”

“…The prevalence of symptomatic radiographic midfoot OA has been shown to be 3.9% in the first cuneiform-metatarsal joint, 6.8% in the second cuneiform-metatarsal joint, 5.2% in the navicular-first cuneiform joint and 5.8% in the talo-navicular joint 6 . Individuals with midfoot OA report greater foot pain and poorer foot function 8,9 and are more likely to have other non-musculoskeletal comorbidities compared to people without midfoot OA 10 . Despite the high prevalence and burden of foot OA, the condition has been largely ignored in the research literature until relatively recently 11,12 .…”

“…Midfoot OA is more prevalent in individuals aged over 75 years, in women and those in intermediate/routine occupational classes, and is associated with obesity, pain in other weight bearing joints and previous foot and ankle injuries 10 . Mechanical factors, such as higher midfoot plantar pressures during walking 8,13 and a flatter foot posture 9,14 , have also been implicated in the development of midfoot OA, and may have a negative impact on physical function 15 . Therefore, understanding how foot structure and function (such as alignment, range of motion or dynamic function) differ between people with and without midfoot OA will assist in elucidating the underlying mechanisms responsible for its development, and inform treatment decisions.…”

Foot and Leg Muscle Weakness in People With Midfoot Osteoarthritis

“…Demonstrated risk factors for midfoot OA include female sex, age, obesity, intermediate/routine occupational class, previous foot/ankle injury, and pain in other weight‐bearing joints (2). Within the foot, midfoot OA is associated with bony malalignment, resulting in reduced medial longitudinal arch height (7) and a more pronated foot posture (8). This is accompanied by reduced sagittal plane range‐of‐motion in the medial longitudinal arch (4) and elevated forces and pressures under the midfoot during walking (7,9).…”