Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments

Table 1 Clinical features and magnetic resonance imaging findings in the four grades of tibial stress injury

Grade	Clinical exam	MRI
1	Periosteal tenderness at the distal 1/3 to 1/2 of the anteromedial tibial surface. Requires firm palpation with thumb	Periosteal oedema: mild to moderate on T2-weighted images. Marrow normal on T1 and T2-weighted images
2	Tenderness as above	Periosteal oedema: moderate to severe on T2-weighted images Marrow oedema on STIR or T2-weighted images. T1 normal
	Requires less firm palpation with thumb and may have linear tenderness along the posteromedial tibial border
3	Tenderness as above	Periosteal oedema: moderate to severe on T2-weighted images. Marrow oedema on T1 and STIR-T2-weighted images
	Requires less firm palpation and may have linear tenderness as above
	May have subcutaneous anteromedial tibial oedema
4	Tenderness as above	Periosteal oedema: moderate to severe on T2-weighted images. Marrow oedema on T1-STIR or T2-weighted images
	Requires less firm palpation and may have linear tenderness as above	Fracture line clearly visible as low fuzzy incomplete (4a) or complete (4b) line
	A discrete region of maximal tenderness/thickening (early callus formation) over the fracture site will be palpable. Obvious tibial subcutaneous oedema is usually present	May see oedema in proximal tibial origins of Tibialis Posterior, FDL and Soleus

Modified by Oakes from Fredericson et al[12] and Pomeranz[11]. MRI: Magnetic resonance imaging; STIR: Short T1 inversion recovery.