MRI abnormalities of tarsal tunnel contents in symptomatic adolescent and young adult patients with talocalcaneal coalition
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background: Adolescent and young adult patients with talocalcaneal coalition (TCC) frequently suffer from recurrent ankle sprains and chronic medial hindfoot pain. Given that TCC may exert variable impacts on tarsal tunnel contents, this study aimed to investigate magnetic resonance imaging (MRI) abnormalities of tarsal tunnel contents in this patient population. Methods: A retrospective analysis was conducted on MRI data of 124 symptomatic adolescent and young adult patients with TCC. TCC lesions were classified according to anatomical location, tissue type, and morphological characteristics. MRI abnormalities of tarsal tunnel contents, including the flexor hallucis longus tendon (FHLT), flexor digitorum longus tendon (FDLT), posterior tibial tendon (PTT), and medial plantar nerve (MPN), were evaluated and their differences were compared. Patients were stratified into abnormal and corresponding normal subgroups based on the MRI findings of the FHLT, FDLT, PTT, and MPN, and inter-group differences in the incidence of various clinical manifestations were evaluated. Results: Among 124 subjects (84 males, median age 23 years), FHLT abnormalities were identified in 66 cases (53.2%), FDLT abnormalities in 22 (17.7%), PTT abnormalities in 6 (4.8%), and MPN abnormalities in 71 (57.3%). No significant difference was observed in FHLT abnormality among the three anatomical types (intra-articular, extra-articular, and mixed type; P>0.05). The rates of FDLT and MPN abnormalities in intra-articular TCC were significantly lower than those in extra-articular and mixed TCC (all P<0.05). No significant difference in PTT abnormality was found between intra-articular and extra-articular TCC (P>0.05), whereas the rate of PTT abnormality was significantly lower in intra-articular TCC than in mixed TCC (P=0.005). Notably, no significant differences in FHLT, FDLT, PTT or MPN abnormalities were observed among TCCs with different tissue types (osseous, fibrous or cartilaginous) or morphological characteristics (types I-IV) (all P>0.05). The prevalence of recurrent sprains with medial ankle pain was significantly higher in the FDLT-abnormal and MPN-abnormal groups than in their respective normal counterparts (P<0.05). For hindfoot stiffness with restricted mobility and symptom exacerbation by activity/prolonged standing and relief with rest, their prevalences were statistically significantly increased in the FHLT-abnormal and MPN-abnormal groups relative to the corresponding normal groups (P<0.05). Associated tarsal tunnel syndrome (TTS) manifesting as plantar numbness or paresthesia and hindfoot valgus were significantly more frequent in all four tendon/nerve abnormal subgroups (FHLT, FDLT, PTT, MPN) compared with normal groups (P<0.05). Conclusions: Symptomatic adolescent and young adult patients with TCC are frequently associated with abnormalities to the tarsal tunnel contents, and MPN abnormality is the most common, followed by FHLT abnormality. Extra-articular and mixed-type TCCs are more likely to cause MPN and FDLT abnormalities.
Authors: Lulu Fan, Zikang Guo, Dongsheng Hao, Ziquan Guo, Rui Li
Institutions: Shanxi Medical University, Shanxi Academy of Medical Sciences
Language: English
Topic: Foot and Ankle Surgery
Subfield: Orthopedics and Sports Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7223249765