Talar Morphology of Charcot-Marie-Tooth Patients With Cavovarus Feet

Background: Charcot-Marie-Tooth disease (CMT), a common inherited neurologic disorder, significantly impacts the morphology of foot bones, particularly the talus. The disease has been classified into types based on specific mutations, with the most common being CMT type 1 (CMT1; demyelinating) and CMT type 2 (CMT2; axonal). However, the specific osseous morphologic variations in CMT patients and their major genetic subgroups remain insufficiently understood, posing challenges in clinical management and surgical intervention. Methods: This study analyzed talar morphology in individuals with CMT compared with a healthy control group, employing a single-bone statistical shape model and talar neck offset angle measurements. Participants included 18 CMT individuals (yielding 29 tali) and 43 healthy controls. For individuals with CMT, the average age at diagnosis was 36.5 ± 19.8 years, with a mean interval of 8.6 years between diagnosis and imaging. Talar morphology was evaluated using weightbearing computed tomography and subsequent morphologic and angular analysis. Results: Differences were observed in talar morphology between CMT and healthy individuals. Notably, CMT1 and CMT2 tali exhibited a flatter talar dome and more medial talar head and neck compared with controls. Additionally, the CMT1 and CMT2 subgroups both had a more medially oriented talar neck based on the talar neck offset angle compared with the controls. Conclusion: The findings illustrate significant morphologic variations in the talus of CMT patients, indicating the need for type-specific clinical approaches in treating CMT-related foot deformities. Understanding these talar variations is crucial for tailoring surgical techniques and orthotic designs, and developing effective rehabilitation protocols for individuals with CMT, potentially improving patient care and outcomes.