Does Tibialis Posterior Dysfunction Correlate with Overall Foot Deformity in Progressive Collapsing Foot Deformity?

• Published in: Foot & ankle orthopaedics 2022-04, Vol.7 (2)
• Main Authors: Lalevée, Matthieu, Mansur, Nacime S., Carvalho, Kepler, Walt, Jennifer S., Vivtcharenko, Victoria, Tazegul, Tutku, Lintz, Francois, Dibbern, Kevin N., de Cesar Netto, Cesar
• Format: Article
• Language: English
• Subjects: Deformities; Feet; Orthopedics
• ISSN: 2473-0114; 2473-0114
• DOI: 10.1177/2473011421S00533

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Posterior Tibial Tendon (PTT) dysfunction is considered to play an important role in Adult Acquired Flatfoot Deformity recently renamed Progressive Collapsing Foot Deformity (PCFD). Previous flatfoot classifications are mainly based on a progressive mechanical failure of the PTT causing chronological appearance of deformities. A consensus of experts recently met and decided to remove the central place of the PTT dysfunction from the PCFD classification system. The primary objective of our study was to assess the relation between the PTT clinical status and the three-dimensional overall foot deformity. The secondary objective was to assess the relation between the degeneration of PTT at the MRI and the three- dimensional overall foot deformity. We hypothesized that the more damaged the PTT, the more severe the deformity of the foot. Methods: We retrospectively identified all symptomatic PCFD over 18 years old who consulted our center from 01/01/2019 to 12/31/2020. PCFD with concomitant (< 3 mois) clinical examination, Weight-Bearing CT (WBCT) and MRI were included. PCFD presenting with previous surgical intervention were excluded. Finally 25 PCFD were included in the analysis (19 Women, mean age 53.96+/-14.9 years, mean BMI 33.2+/-8.1 kg/m2;)A PCFD presenting either a deficit on the single heel rise test or a decrease in inversion strength (superior or equal to 3/5) was classified PTT deficient. The MRI of all these PCFD were analyzed, and PTT degeneration was classified according to Deland and Rosenberg classifications. The three-dimensional overall deformity of each PCFD was assessed on WBCT by the Foot and Ankle Offset (FAO). Normality of different variables were assessed using Shapiro- Wilk test. Comparisons were performed using Student's t-test or Anova for normal, and Mann-Whitney or Kruskal-Wallis's test for non-normal variables. Results: Patients with clinically deficient PTT (13/25 PCFD, 52%) had a mean FAO of 7.75+/-3.8% whereas patients without PTT deficit (12/25 PCFD, 48%) had a mean FAO of 6.68+/-3.9%, without significant difference between groups (p=0.49). According to Deland classification, 4/25 PTT (16%) were classified grade 0, 7/25 (28%) grade 1, 4/25 (16%) grade 2, 5/25 (20%) grade 3 and 5/25 (20%) grade 4 without any significant difference between groups (p=0.36).According to Rosenberg classification, 4/25 PTT (16%) were classified type 0, 15/25 (60%) type 1, 2/25 (8%) type 2 and