Thurston-Holland sign is a radiographic feature associated with which fragment in Salter-Harris type II fractures?

• A. A triangular metaphyseal fragment
• B. A cortical irregularity along the diaphysis
• C. A depression fracture of the joint surface
• D. An avulsion fragment from the metaphysis

Answer: (A)

In Salter-Harris type II fractures, the fracture line runs through the growth plate and into the metaphysis, sparing the epiphysis. The Thurston-Holland sign is the radiographic appearance of a small triangular wedge of metaphysis—the triangular metaphyseal fragment—that has been separated by this fracture line. This wedge is the distinctive cue that identifies a type II injury on imaging because the fracture pattern uniquely creates that metaphyseal fragment while the epiphysis and joint surface remain intact. Other features such as a cortical irregularity in the diaphysis, a depressed joint surface, or a different kind of metaphyseal fragment do not reflect this specific fracture pattern.