Fatigue stress fractures of the sacrum: diagnosis with MR imaging

Abstract

The aim of this study was to describe the MRI findings and clinical observations in a fatigue stress fracture of the sacrum. In this retrospective study, 380 conscripts (53 women, 327 men; age range 18-29 years, mean age 20.7 years) who suffered from stress-related hip pain were studied with MRI of the pelvis. The findings of MRI were evaluated with regard to stress fracture of the sacrum. Thirty-one (8%) patients had MRI changes in signal intensity of the cranial part of the sacrum, extending to the first and second sacral foramina. The MRI changes in signal intensity were intermediate on T1-weighted images, and high on short tau inversion recovery or T2-weighted fat-suppressed images. A linear signal void fracture line was also seen. Multiple stress injuries to the pelvic bones were also seen in 7 of 31 (23%) patients. Five patients (16%) had bilateral sacral stress fracture. Fatigue sacral stress fractures appeared more commonly in women than in men ( p<0.001). During recovery time 20 of the 31 patients underwent control MRI, and fatty marrow conversion was seen in 8 (40%) cases as high signal intensity on T1-weighted images, which disappeared 5-6 months after the onset of symptoms. Fatigue sacral stress fractures are associated with stress-related hip pain. These fractures were more common in women than in men. Other stress injuries of the pelvis may be seen simultaneously with sacral stress fractures. Signal intensity of the sacrum was normal after 5-6 months.

Bone Stress Injuries Are Common in Female Military Trainees: A Preliminary Study

“…It was shown MRI-diagnosed bone stress injuries of the pelvis and femoral neck are substantially more common among female recruits than among male conscripts [1,17,22]. In the current study, repeated MRI examinations of female military recruits undergoing heavy physical training revealed not only symptomatic high-grade bone stress injuries but also a great number of asymptomatic low-grade bone stress injuries.…”

“…In addition, the anatomic location of these injuries varies by gender [7,15,22]. It previously was reported MRI-diagnosed bone stress injuries of the pelvis and femoral neck are substantially more common among female recruits than among male conscripts [1,17,22].…”

Sonographic findings in stress fractures of the lower limb: preliminary findings

“…MRI and scintigraphy are currently the gold standard for the radiological diagnosis of stress fractures [3][4][5]. Only one case report describes sonographic imaging of a stress fracture [6].…”

Sacral Fatigue Fracture in a Female Runner: A Case Report

“…29 The characteristic MRI appearance of an SFF is an area of decreased signal intensity on T 1 -weighted images in the superior portion of the sacral ala. On T 2 -weighted images, high signal intensity is seen, often surrounding a linear low signal intensity, representing the fracture line. 30 This MRI appearance is considered to be diagnostic. 1,30 The high signal intensity on T 2 -weighted images represents edema of the bone marrow (Fig 3) and has the potential to be misinterpreted as neoplasia in certain cases.…”

“…30 This MRI appearance is considered to be diagnostic. 1,30 The high signal intensity on T 2 -weighted images represents edema of the bone marrow (Fig 3) and has the potential to be misinterpreted as neoplasia in certain cases. However, fairly reliable differentiation between malignancy and stress fractures can be achieved with the appropriate choice of imaging parameters.…”