Application of ultrasound in preoperative localization diagnosis of checkrein deformity: A retrospective case series.

Background: Checkrein deformity, is a rare claw toe dynamic deformity of the hallux or great toe. This study investigated the use of diagnostic ultrasound in positioning the accurate injury location causing checkrein deformity and its clinical significance for etiological diagnosis and selection of surgical methods.

Methods: This retrospective study included patients with confirmed checkrein deformities (according to typical symptoms) at the Department of Traumatic Orthopedics of Tianjin Hospital (Tianjin, China) from March 2017 to July 2021.

Results: A total of 11 patients (8 males and 3 females) with a mean age of 36.7 ± 16.8 (range 19-61) were included in this study. The injuries included six cases of tibia and fibula fracture, one case of single tibia fracture, and one case of single fibula fracture. Four patients were treated with steel plate internal fixation, three patients with intramedullary nailing, and one patient with external fixation. Three patients reported no history of any high-energy trauma or surgery. The ultrasound results showed that seven patients suffered from flexor hallucis longus (FHL) lesions, two patients suffered from flexor digitorum longus (FDL) lesions, and two patients suffered from FHL and FDL lesions. The patients underwent different surgeries tailored to their specific lesions. Toe flexion deformity was completely corrected after operation in all patients. The function of the toes was recovered to varying extent.

Conclusion: The results of this study demonstrates that the checkrein deformities can be confirmed by ultrasound. It could be used to determine the adhesions before the operation, acting as guidance while establishing the surgical planning.