In the group of patients over 45 with ankle fractures, two out of three should be screened for osteoporosis. In the over-60 s with ankle fractures, one in two patients has an indication for specific therapy, but almost no one receives it.

The inclusion criterion was adults over the age of 45. The group was as expected in terms of gender and age distribution. Given an increasingly ageing population, an average age of 66 is representational [4]. A majority of women was also expected due to the gender distribution in this age group. This means that the cohort studied represents the expected population.

The fact that 85% of the patients aged 60 years and older in the study group had an indication for a diagnostic test of osteoporosis, even without considering the ankle fracture as an osteoporosis-associated fracture, is evidence for the authors of the vulnerability of this patient group. According to the still valid DVO guidelines, age only leads to a purely age-related indication for diagnostic testing for osteoporosis starting at 70 for women and 80 for men.

To the authors’ knowledge, there is no literature on the diagnostic gap for ankle fractures or other fracture entities. For this reason, the comparison was made with internal, unpublished data. For the whole group of ankle fractures reported here, the proportion of patients with an indication for baseline assessment was lower (61%) compared with 73% for radial fractures in the same age group and time period. However, the diagnostic gap of 67% was higher than the 53% for radius fractures. The diagnostic gap underlines the fact that the osteoporotic risk is still significantly underestimated in the ankle fracture group, according to the authors.

In terms of treatment, the picture is similar to the basic diagnostic testing. For the authors, the fact that only one patient received osteoporosis drug therapy is an expression of the 78–80% therapeutic gap in Germany, as reported in the literature [5]. Again, there is a lack of studies on individual fracture entities, so a comparison is also made with the osteoporotic pattern fracture of the distal radius. According to unpublished data from the same period in our clinic, 56% of patients with surgically treated distal radius fractures have an indication for specific therapy, which is lacking in 84% of these patients (= therapy gap). For ankle fractures, there is an indication for treatment in 33% of patients, which is significantly lower. This lower proportion can be explained by the incidence of both types of fracture. While there is a clear peak in the incidence of distal radius fractures in the second age group, the incidence of ankle fractures is more or less the same in all age groups. However, looking at the therapeutic gap between patients, it was 95% for ankle fractures and 84% for distal radius fractures. Thus, the exclusion of ankle fractures as osteoporosis-related seems to lead to an underestimation of the likelihood of osteoporosis in patients, both in terms of therapy and diagnostic testing.

Court-Brown and McQueen have shown that the incidence of ankle fractures does not increase with age, but remains constant in both men and women. This argues against the use of ankle fracture as an osteoporosis-related fracture. They were also able to show that the classic osteoporosis-associated fractures such as the distal radius fracture or the proximal femur fracture as well as the proximal humerus fracture are part of the same fracture type, characterized by an increase in incidence with age, and this is independent of gender [6]. This is a significant difference from ankle fractures.

In a retrospective analysis, Lee et al. [4] found that patients with ankle fracture did not have a lower bone density index than the control group; rather, they had a higher body mass index. From these findings, they concluded that there is no association between ankle fractures and osteoporosis.

Hjelle et al. [7] demonstrated that, compared to a control group, patients with a high BMI had an increased risk of ankle fracture, while the bone density in the fracture group was similar to that in the control group. The authors therefore conclude that there is no association with osteoporosis. The DXA scans of the patients reported that only 30% had normal bone density, whereas 22% had osteoporosis and the remaining 48% had osteopenia. In view of these results, ankle fractures are also suitable for identifying patients with osteoporosis (case finding).

Therdyothin et al.’s [8] systematic review only identified 19 studies on whether there is a higher occurrence of subsequent fractures or lower bone density in individuals with ankle fractures, in comparison to those without. The results of the studies vary. Therefore, there is no consistent evidence for or against the hypothesis that ankle fractures are associated with osteoporosis. However, it is worth noting that five of the eleven studies showed an increased risk of subsequent fractures. However, not all of the studies addressed this question. Overall, the authors conclude that the literature is inconclusive, nevertheless suggesting an association for geriatric patients. Therefore, this notion supports the employment of ankle fractures as a case finding measure, instead of disregarding them as non-osteoporotic from the beginning.

The data collected on indications for diagnostic testing and treatment for osteoporosis, which are lower than those for distal radius fractures, may also explain why ankle fractures are, by definition, not osteoporosis-associated fractures. Nevertheless, the figures prove that it is currently very reasonable in everyday clinical practice to treat them as such with regard to diagnostic screening for osteoporosis. The authors’ view is supported by the new draft guideline on osteoporosis therapy in postmenopausal women. This guideline no longer explicitly excludes ankle fractures as osteoporosis-associated fractures and focuses more on case finding.

With 131 patients, the group presented here is small. However, it is a representative group due to the two-year time period. This period avoids seasonal bias. Furthermore, with 66 patients, the statistical power is already sufficiently high at 0.8 for an expected therapeutic gap of 80% in the total population. Another limitation is the lack of DXA scans of the patients. This would have supported the diagnostic testing for osteoporosis according to the current gold standard. However, it was not possible to integrate this measurement into the clinical routine. The lack of DXA scans is a common phenomenon in everyday clinical practice. Therefore, this study used the FRAX calculator risk calculation, which is known to have a good correlation with osteoporosis in the absence of a bone density measurement [3, 9, 10].

In the present study, no comparison was made with the normal population in the sense of a control group. This was not done because the question was about the incidence of osteoporosis in the group of patients with ankle fractures and, in addition, it was investigated whether the ankle fracture is suitable for case finding in diagnosing osteoporosis. Neither of these questions requires a control group.