title: Could failure of the spring ligament complex be the driving force behind the development of the adult flatfoot deformity?
abstract: We conducted an investigation into the relative associations of magnetic resonance imaging (MRI)-defined pathologic features of the spring ligament and/or tibialis posterior tendon with radiographic evidence of a planovalgus foot position. A total of 161 patient images (MRI and plain radiographs) obtained from the foot and ankle clinic (2008 to 2011) were retrospectively reviewed. All 161 patients (64 male and 97 female; mean age 45.9 years, range 18 to 86) were included in the analysis. Lateral weightbearing radiographs were analyzed for the talo-first metatarsal angle ≥ 5°, calcaneal pitch ≤ 20°, and talocalcaneal angle ≥ 45°. A positive finding for ≥ 1 measurements identified a radiographic planovalgus position of the foot. The radiographic deformity was analyzed against the MRI evidence of either spring ligament or tibialis posterior tendon pathologic features for significance (p < .05). Evidence of a spring ligament abnormality was strongly associated with a planovalgus foot position, reaching high levels of statistical significance in all 3 categories of radiographic deformity (odds ratio 9.2, p < .0001). Abnormalities of the tibialis posterior tendon failed to demonstrate significance, unless grade I changes were excluded, and grade II and III appearances were analyzed in isolation (odds ratio 2.9, p = .04). Although absolute causal relationships were not tested, this investigation has clearly demonstrated that MRI-defined abnormalities of the spring ligament complex are possibly of at least equal importance to tibialis posterior dysfunction for the presence of a moderate to severe radiographic planovalgus foot position.
authors.affiliation: Wirral Univeristy Hospital, National Health Service, Arrowe Park Hospital, Upton, Wirral, UK. Electronic address: geraint.williams@nhs.net.
authors.forename: Geraint
authors.initials: G
authors.lastname: Williams
authors.affiliation: Wirral Univeristy Hospital, National Health Service, Arrowe Park Hospital, Upton, Wirral, UK.
authors.forename: James
authors.initials: J
authors.lastname: Widnall
authors.affiliation: Wirral Univeristy Hospital, National Health Service, Arrowe Park Hospital, Upton, Wirral, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Evans
authors.affiliation: Wirral Univeristy Hospital, National Health Service, Arrowe Park Hospital, Upton, Wirral, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Platt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005413:Flatfoot / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008023:Ligaments, Articular / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013710:Tendons / Q000503:physiopathology*; D055815:Young Adult
keywords: adult acquired flatfoot deformity; magnetic resonance image (MRI); navicular; planovalgus; talus; tibialis posterior tendon