Background Stress fractures are common in both young and active patients (fatigue fracture) as well as in elderly osteoporotic patients (insufficiency fractures).
Objectives The aim of this study was to describe characteristics of stress fractures treated in rheumatology at the Clermont-Ferrand University Hospital, to compare them according to their anatomic location (pelvis, lower limb or feet/ankle) and their diaphyseal or metaphyseal/epiphyseal location.
Results Between 01/01/2000 and 12/31/2015, 325 fractures were identified in 227 patients divided in 176 women (including 116 postmenopausal women) and 51 men. Population averaged age was 65.2 years [15–99 years]. 142 (43.7%) fractures occurred at pelvis, 93 (28.6%) at lower limbs and 87 (26.8%) at feet and ankles. The fracture was spontaneous in 63.6% of cases. History of pain was recorded in 92.3% with more frequently (90.3%) mechanical pain. Diagnostic delay was on average 70 days.
In 51 patients (22.5%) an orthopedic factor could have promoted stress fracture. 54 patients (23.8%) had a history of chronic inflammatory rheumatism, 28 (12.3%) of cancer, and 20 (8.8%) had chronic renal failure.
Among the possible iatrogenic factors, 51 patients (23.4%) received oral corticosteroid therapy, 20 (9.2%) methotrexate, 59 (27%) proton pump inhibitor and 17 (7.8%) serotonin reuptake inhibitor. 49 patients (22.5%) already had vitamin-calcium supplementation, 37 (17%) received biphosphonate therapy. 56.6% were osteoporotic and 29.5% were osteopenic.
First-line medical imaging was in 87% conventional radiography, positive in 37%. 106 patients (46.7%) performed bone scan with a sensibility of 99%. MRI sensibility (n=65, 28.7%) was 88% and CT-scan sensibility (n=47, 20.7%) 65.2%.
Compared to other sites, pelvic fractures were more frequent (p<0.001) and occurred more frequently in postmenopausal women (p=0.03). These patients were older (p<0.001) and had more fracture history (p=0.006). Hip bone mineral density (p=0.03) was lower, and osteoporosis prevalence higher (p=0.004).
Pelvic fractures occurred more frequently after fall (p<0.001), lower limb fractures spontaneously (p=0.03) and those of the feet-ankles group after an unusual activity (p<0.001). Patients from metaphyseal-epiphyseal fracture group were older (p=0.05) than those from the diaphyseal fractures group and delay in completing complementary examinations was longer (p=0.04).
Conclusions In conclusion, pelvic stress fractures are more frequent in a rheumatology department and suggest insufficiency fracture. Stress fracture should be more often suspected when mechanical pain of the pelvis and lower limbs occurs, even spontaneously. Regardless of the site, an assessment of fracture risk factors and bone mineral density evaluation seems necessary.
Disclosure of Interest None declared