Age / Sex : 20 / M

Chief complaint : left forearm pain for 6 weeks
PHx : serving in the military as a cook using a wok pot


What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer)

Courtesy : 이슬기 (Seul Ki Lee), 성빈센트 병원(St. Vincent’s Hospital)

Stress fracture of ulna

Discussion

Findings

1.Radiographs showed periosteal reaction with cortical thickening at the mid portion of the ulnar shaft.

2.MRI shows extensive bone marrow edema along the ulnar shaft. Axial T2WI demonstrated segmental periosteal reaction with edema in the volar side of the mid-ulnar shaft.

3.Although a typical transverse fracture line was clearly visible, T2 hyperintense and T1 isointense curvilinear foci were seen within the cortical thickening.

4.Periosteal soft tissue edema was seen adjacent to the flexor digitorum profundus muscle. 

5.A follow-up plain radiograph confirmed that there was ongoing solid union


Differential diagnosis

Osteoid osteoma
Intracortical abscess

Reference

Tanabe S, Nakahira J, Bando E, Yamaguchi H, Miyamoto H, Yamamoto A. Fatigue fracture of the ulna occurring in pitchers of fast-pitch softball. The American journal of sports medicine. 1991;19(3):317-21