Longitudinal Stress Fracture

Longitudinal stress fractures are uncommon fractures that are thought to be related to rotational stress. While they most commonly occur in the tibia, cases have also been reported in the femur and fibula.

The diagnosis is most readily made on CT by noting a fracture plane oriented along the long axis of the bone. MRI may also allow visualization of the fracture plane, but has a lower sensitivity. MRI can, however, suggest the diagnosis by revealing bone marrow edema starting at the entry of the nutrient foramen of the tibia, eccentric periosteal reaction and new bone formation, and eccentric soft tissue edema. The relationship between the nutrient foramen and the fracture plane is an interesting one. It has been suggested that the foramen may be a potential area of weakness in some patients, with some tibial longitudinal fracture planes starting within the foramen.

The image above shows the CT and MRI from a patient with a longitudinal stress fracture. The CT demonstrates the fracture plane with endosteal and periosteal callus formation along the anteromedial margin of the tibia. No communication between the nutrient foramen and the fracture plane was noted on CT. The first axial STIR image shows the medullary end of the nutrient foramen (yellow arrow). The second axial STIR image is just distal to the first and shows marrow edema and eccentric soft tissue edema. No fracture plane could be seen on MRI. The radigraphs, even in retrospect, were normal.

References

• Allen GJ. Longitudinal stress fractures of the tibia: diagnosis with CT. Radiology. 1988 Jun;167(3):799-801.
• Craig JG, Widman D, van Holsbeeck M. Longitudinal stress fracture: patterns of edema and the importance of the nutrient foramen. Skeletal Radiol. 2003 Jan;32(1):22-7. Devas MB. Longitudinal stress fractures. Another variety seen in long bones. J Bone Joint Surg Br. 1960 Aug;42-B:508-14.
• Feydy A, Drapé J, Beret E, Sarazin L, Pessis E, Minoui A, Chevrot A. Longitudinal stress fractures of the tibia: comparative study of CT and MR imaging. Eur Radiol. 1998;8(4):598-602.
• Goupille P, Giraudet-Le Quintrec JS, Job-Deslandre C, Menkes CJ. Longitudinal stress fractures of the tibia: diagnosis with CT.
• Saifuddin A, Chalmers AG, Butt WP. Longitudinal stress fractures of the tibia: MRI features in two cases. Clin Radiol. 1994 Jul;49(7):490-5.