Fredericson Grading of Tibial Stress Reaction

Fredericson system is a 5-level grading scheme for tibial stress reactions developed by studying symptomatic runners. In symptomatic patients, it correlates with the time for return to full impact activity.

The MRI findings have to be correlated to symptoms, as a follow-up study showed that almost half of asymptomatic college distance runners had signs of tibial stress reaction on MRI. In addition, these changes did not predict future tibial stress reactions or stress fractures.

Grade	MRI Findings	Time to full-impact activity*
0	Normal MRI findings.
1	Increased periosteal T2 signal. Normal marrow signal intensity on all images (shown here)	2 to 3 weeks
2	Grade 1 plus bone marrow signal changes on T2-weighted images	4 to 6 weeks
3	Grade 2 plus bone marrow signal changes on T1-weighted images (shown above)	6 to 9 weeks
4	Grade 3 plus a clearly visible fracture plane
*Full impact activity: Ablility to return to running on grass or a soft dirt track

References

• Bergman AG, Fredericson M, Ho C, Matheson GO. Asymptomatic tibial stress reactions: MRI detection and clinical follow-up in distance runners. AJR Am J Roentgenol. 2004 Sep;183(3):635-8.
• Fredericson M, Bergman AG, Hoffman KL, Dillingham MS. Tibial stress reaction in runners. Correlation of clinical symptoms and scintigraphy with a new magnetic resonance imaging grading system. Am J Sports Med. 1995 Jul-Aug;23(4):472-81.