Correlation of Weight-bearing Computed Tomography and Magnetic Resonance Imaging Findings in Flatfoot Deformity

Purpose or Learning Objective: The presence of sinus tarsi impingement in flatfoot deformity (FFD) can be assessed via weight-bearing computed tomography (WBCT) and serve as guidance for recommendations on realignment fusion surgery. Because WBCT is not always available, we aimed to assess whether significant correlation exists between WBCT and magnetic resonance imaging (MRI) findings.

Methods or Background: In this retrospective study, 24 patients presenting with various stages of FFD (age: 51 ± 18 years; 12 women) underwent WBCT (Multitom Rax, Siemens Healthineers, Erlangen, Germany) and MRI. In addition to signs of sinus tarsi impingement, four commonly used three-dimensional measurements were assessed with dedicated postprocessing software (DISIOR 2.1) on the WBCT datasets. Sinus tarsi obliteration, spring and tibiospring ligament integrity, as well as tibialis posterior tendon degeneration, were evaluated on MRI. Statistical analysis was performed to assess whether there was significant (P < 0.05) correlation between WBCT and MRI findings.

Results or Findings: A total of 35% of patients with evidence of sinus tarsi impingement on WBCT scans did not show sinus tarsi obliteration on MRI. Spring ligament rupture was evident in 43% of patients without sinus tarsi impingement on WBCT. Of note, 24% of patients with sinus tarsi impingement on WBCT did not show spring ligament rupture on MRI. No patient without sinus tarsi impingement on WBCT showed tibiospring ligament or tibialis posterior tendon rupture on MRI. However, 59% and 76% of patients with sinus tarsi impingement did not show tibiospring ligament or tibialis posterior tendon rupture, respectively. An increased Meary's angle and talocalcaneal overlap, assessed on WBCT, were associated with tibiospring ligament and tibialis posterior tendon rupture (P < 0.05).

Conclusion: The sinus tarsi was obliterated in most but not all ankle MRI studies in patients with WBCT evidence of sinus tarsi impingement. MRI diagnoses of ligament and tendon injuries showed only limited correlation with the WBCT diagnosis of sinus tarsi impingement.

Publication History

Article published online:
26 May 2023