Radiographic Comparison of Standing Medial Cuneiform Arch Height in Adults With and Without Acquired Flatfoot Deformity

Background: Adult acquired flatfoot (AAF) is characterized by decreased arch height, talar depression, medial arch depression and elongation, and forefoot abduction. We have measured standing arch height in AAF patients and in a control group of patients using the standing lateral medial cuneiform arch height radiographic measurement. Methods: Fifteen (25 feet) patients were selected with the clinical diagnosis of symptomatic AAF with no secondary diagnoses. A control group consisted of 36 (72 feet) patients with no foot deformities or prior foot surgeries. Arch height was measured in millimeters using the standing medial cuneiform height on the lateral radiographic view. Results: The mean standing medial cuneiform arch height in the control group was 18.38 mm. The mean arch height in the AAF group was 11.04 mm ( p < 0.001). There were no differences between right and left feet in the control group or symptomatic and contralateral feet in the AAF group. Body mass index (BMI) in the control group was 26.17 and in the AAF 33.74. ( p = 0.007). Conclusion: These data provide a control value for the arch height using the medial cuneiform as reference. The decrease in arch height is a strong indicator of AAF. A study with larger numbers of patients is necessary.