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.

Table 2 Bone mineral density in male medial tibial stress syndrome patients and an athletic control group[31]

BMD (g/cm2)	MTSS	Athletic control	Significance
Proximal	1.29	1.48	< 0.01b
33% level (injury site)	1.43	1.85	< 0.001b
Distal	1.32	1.33	> 0.05

^bStatistically significant. Although there are differences in the proximal tibia, the difference is much greater at the injury site. Select data presented for comparison with the two other BMD studies discussed. BMD: Bone mineral density; MTSS: Medial tibial stress syndrome.

Table 3 Bone mineral density in female tibial stress fracture and medial tibial stress syndrome patients[33]

BMD (g/cm2)	MTSS (n = 20)	TSF (n = 10)	Significance
Proximal	1.21	1.27	0.136
33% level (injury site)	1.46	1.63	0.013a
Distal	0.90	0.94	0.403

^aStatistically significant. BMD: Bone mineral density; MTSS: Medial tibial stress syndrome; TSF: Tibial stress fracture.