Proximal femur fractures are the most frequent traumatic skeletal lesions. Despite improved understanding of the risk factors for and means of preventing these fractures, their frequency continues to increase. In Italy there are estimated to be more than 80000 new proximal femur fracture cases every year. These fractures are closely correlated with osteoporosis and are therefore more frequent in the elderly population. Indeed, other fracture risk factors are age and falls. Cognitive decline is one of the intrinsic risk factors for falling as it influences postural control and lower limb muscle strength.
Hip fracture itself is an event capable of triggering a progressive cognitive decline; the incidence of this ranges from 16% to 62% and it is associated with increased morbidity and mortality. The aim of this study was to describe the association between cognitive decline and proximal femur fractures.
Materials and methods:
As part of Indaco 2, an epidemiological survey proposed by SIOT (the Italian Society of Orthopaedics and Traumatology), data were collected relating to 7355 patients attending over 100 orthopaedics and traumatology clinics throughout Italy, recruited over a 6-month period. A questionnaire was administered that, as well as covering various aspects of the patient’s history, also included the Short Portable Mental Status Questionnaire(SPMSQ). This instrument is made up of 10 items that assess the patient’s cognitive abilities.
From the 7355 questionnaires collected, we excluded those referring to patients under the age of 65 years, this parameter being a criterion for exclusion from the study; we also excluded those with an incomplete SPMSQ. We then excluded, from the remaining 6294 questionnaires, those that failed to provide anamnestic data on the femur fracture. Therefore, the final analysis was performed on 6285 patients, who had a mean age of 77 years (±7.55).
The patients with a femur fracture totalled 2877 and their mean age was 80.3 years (±7.55). The fracture-free patients numbered 3408, and had a mean age of 74.2 years (±6.32). For the final analysis, we dichotomised the SPMSQ variable, thus forming two groups: one comprising patients with normal to mildly impaired cognitive status, and the other patients with moderately to severely impaired cognitive status.
In the group of fracture patients, the SPMSQ showed normal to mildly impaired cognitive status in 67% of the patients, who had a mean age of 78.28 years (±7.2), and moderately to severely impaired cognitive status in 33%, who had a mean age of 84.41 years (±6.49). In the fracture-free population, on the other hand, 90.75% of the patients, with a mean age of 73.64 years (±6.03), showed normal to mildly impaired cognitive status, while only 9.25%, with a mean age of 79.64 years (±6.56), showed moderately to severely impaired cognition. The difference in cognitive status between the two groups (fracture and fracture-free) was statistically significant (p< 0.0001), even after adjusting for the age of the patients.
The results of our epidemiological study confirm that cognitive status is more impaired in patients with fractures compared with fracture-free subjects, even after adjusting for age. However, the question of whether cognitive decline was the cause of, or secondary to, the fracture it remains to be established.