Lower limb stress fractures in sport: Optimising their management and outcome

Table 1 Classification systems for lower limb stress fractures

	Arendt scale[17](MRI based)	Federicson scale[16](MRI based)	Saxena classification[18](CT based)	Torg classification[19](radiograph based)
Location of use	Generic	Generic	Navicular	5th Metatarsal Base
Grade 1	STIR signal change	periosteal edema - bone marrow normal	Dorsal cortex involved	Acute fracture line, no intramedullary sclerosis or periosteal reaction
Grade 2	STIR and T2 change	periosteal and bone marrow edema - T2 change only	Dorsal cortex and body involved	Widened fracture line with intramedullary sclerosis and periosteal reaction
Grade 3	STIR, T1 and T2 change - no fracture line present	periosteal and bone marrow edema - T1 and T2 change - no fracture line	Dorsal and Volar cortices involved	Widened fracture line with complete intramedullary sclerosis and periosteal reaction
Grade 4	STIR, T1 and T2 change - fracture line present	periosteal and bone marrow edema - STIR, T1 and T2 change - fracture line	-	-

MRI: Magnetic resonance imaging; CT: Computed tomography; STIR: Short tau inversion recovery.