CASE 39

By: Dr. Mai Mattar, MD & Dr. Nizar Al-Nakshabandi MD, FRCPC

HISTORY: A 20-year-old new military recruit complains of leg pain following exercise.

What are your findings?

What is the differential diagnosis?

What are the causes?

FINDINGS:

(A) Plain radiography shows periosteal reaction along the posterior cortex of the distal tibia.

(B) Coronal T1 and T2FS, Sag PD and axial T2FS demonstrating cortical thickening and a clear fracture line across the cortex with edema within the medullary cavity and the surrounding periosteum.

DIFFERENTIAL DIAGNOSIS:

• Tibial stress fracture.

• Osteoid osteoma.

• Sclerosing osteomyelitis.

DIAGNOSIS:

Tibial stress fracture.

PEARLS AND DISCUSSION:

Two types of stress fracture are seen. The first is a fatigue fracture which is abnormal stress on normal bone. Second one is insufficiency fracture where normal stress occurs on abnormal bones. Insufficiency fracture is not a pathological fracture. Pathological fractures are observed for fractures occurring at the site of a focal bony abnormality such as a tumor.

Stress fractures appear more commonly in long bones in the lower limbs than in the upper limbs. Sites include: Anterior cortex of the tibia such as in our case. Other locations such as the posterior tubercle of the calcaneus, base of the fifth metatarsal, Neck of the second to fourth metatarsal, great toe sesamoids, talar neck, navicular bone, medial malleolus, femoral head, patella, and pars inter-articularis of the lumbar spine.

Imaging as is shown in the findings.

Treatment is determined by the site of stress fracture and suitability for rehabilitation. High-risk patients require orthopedic consultation. One should address diet, calcium and vitamin D.

FURTHER READING:

1. Burgener FA, Kormano M, Pudas T. Bone and Joint Disorders. Thieme Medical Pub. (2005) ISBN:1588904458. 

2. Elstrom JA, Virkus WW, Pankovich A. Handbook of fractures. McGraw-Hill Professional. (2006)     ISBN:0071443770. 

3. Gaeta M, Minutoli F, Mazziotti S et-al. Diagnostic imaging in athletes with chronic lower leg pain. AJR Am J Roentgenol. 2008;191 (5): 1412-9.