Classification of Hamate Fractures: An Analysis of 247 Patients with Hamate Fractures.

Background: We devised a new classification of hamate fractures named the TOUCH classification. Each letter of this acronym depicts a fracture type - Type I (Transverse fracture), Type II (Open and/or complex fracture), Type III (Ulnar/medial tuberosity fracture), Type IV (Coronal fracture) and Type V (Hook fracture). Each fracture type was further divided into two or three subtypes (a, b, and/or c) based on degree of severity. The aim of this study is to classify the hamate fractures treated at our centre using this classification. Methods: A retrospective review of all patients with hamate fractures treated at our hospital between 2003 and 2022 was done. Patient data with regard to age, gender, mechanism of injury, injured limb and any associated injuries was collected. Hamate fractures were classified based on the TOUCH classification. Results: A total of 247 patients with hamate fractures were included. Patients in the age group of 20-40 years accounted for 73.6% of all fractures. Female patients accounted for only 6.9% of all fractures and 76.5% of women with hamate fractures were older than 40 years. The incidence of hamate fracture tended to increase with age in women. The most common mechanism of injury was a fall (69 patients). The injury involved the right upper limb in 195 patients. And 164 patients had associated injuries in the same upper limb. Type III (coronal fracture of the hamate body) accounted for 57.4%, followed by type V (hook of hamate fracture) in 26.7% of patients. Conclusions: The TOUCH classification could cover all kinds of hamate fractures. It is easy to remember and may guide surgeons in considering treatment options. Level of Evidence: Level IV (Diagnostic).