Background The novelty of this study is that it looks at stress fractures using an approach that is not solely mechanical, but also includes bone metabolism.
Objectives The most common site of these fractures is the foot. The aim of this study was to find out whether they are a risk factor for osteoporosis.
Methods This was a three-year study carried out by 15 rheumatologists with private patients. 45 patients were identified (35 women, 10 men) 95.6% of them Caucasians. A control group of 70 patients was constituted with the same age and sex criteria and including previous history and lifestyle.
Results The mean age at which the fracture occurred was 52 years for men and 57 years for women. The mean BMI was 26.7kg/m²; a recent increase in weight of >5 kg was reported in 17% of cases.
71% were working, 44% engaged in sport, half of them on a regular basis. In 62.2% of cases, the fracture occurred during physical activity, and in 42.8% while walking. In 1/2 cases, the foot had been overworked, in 1/4 there had been a change in footwear or a change in the placing of the foot.
The metatarsal was fractured in 64% of cases (2>3>4>5). The right foot was affected in 64.4% of cases, 82.2% of them in right-handed people, the foot displayed pes cavus in 65% of cases. Overwork or excessive sports activity was identified in 26.7% of cases.
The diagnosis was reached by MRI in 44% of cases, and by X-ray in 40%, after a mean of 44 days.
19% of the cases reported had a history of fracture, and 62% had some other risk factor for osteoporosis: smoking in 28.9% of cases and osteoporosis-inducing disorders or treatments in the same percentage of cases.
75.6% had a dietary calcium intake of <1 g/24 hours (more of them women), and 71% had a 25 OHD < 20ng; these two criteria stood out relative to the control group.
19 out of the 45 had undergone a BMD test before the fracture:
of the spine (15.7% osteoporotic, 42% osteopenic)
of the femur (6.6% osteoporotic, 33% osteopenic)
29 out of the 45 had undergone a BMD at the time of the fracture:
of the spine (13% osteoporotic, 52% osteopenic)
of the femur (5% osteoporotic, 57% osteopenic)
Definitely more cases of osteopenia were therefore detected at the time of the fracture than in previous determinations, but also more than in the 17 control patients (41%).
31.1% reported clinical sequelae (pain and some cases of algoneurodystrophy).
Conclusions Stress fractures of the foot are seen more often in overweight women in their 6th decade of life; they occur during physical activity, particularly walking. Overworking of the foot was reported in1/2 cases, with the metatarsal the most common fracture site. The diagnosis was usually reached using X-ray or MRI. In 71% of cases, a risk factor for osteoporosis was found; in 19% this was a previous fracture.
The calcium intake was often insufficient and there was often a 25 OHD deficiency, more often than in the controls.
The BMD results were usually osteopenic at both sites tested, significantly so compared to previous BMD results and to the control BMD data. Bone density was normal in 1/3 of cases, and when osteoporosis was present it was more marked on the spine.
There was a link between bone fragility and stress fractures, since the bone was not “normal” in 65% of cases versus 48% in the control group.
Disclosure of Interest None Declared