Purpose of the study: Dementia in the elderly subject aged over 75 years is currently an important public health problem. An important part of the activity in orthopaedic surgery involves this age group. In 2007, 16,812 elderly persons aged over 75 years were hospitalised in our University Hospital (769 in orthopaedic surgery): 1380 patients were considered demented (40 in orthopaedic surgery). The purpose of this work was to evaluate the cognitive function of this population in a teaching hospital unit of orthopaedic and traumatology surgery where the prevalence of dementia appears to be underestimated.

Material and methods: Data were collected over a period of four years. This study concerned 113 patient, including 83 women, mean age 81.8 years (range 75–92). The reason for hospitalisation was predominantly fracture of the proximal femur (73%); thirty patients had hip, knee or shoulder arthroplasty and 24 other situations. The Mini Mental State Examination (MMSE) was performed.

Results: The MMSE could be interpreted for 100 patients: < 24 for 33, 24 to 26 for 29 and > 27 for 38. Among the 24 patients with no cognitive disorder known before hospitalization (nine patients known to be demented were removed from the analysis) and for whom the MMSE was completed entirely, the most frequent alterations were noted for attention, calculation, and recall-memory items.

Discussion: Finally, one-third of the subjects aged over 75 years and hospitalized in our unit presented signs of altered cognitive function according to the MMSE(< 24). This score is one of the criteria for frailness of the elderly subject. This population has an unstable precarious medicosocial status with defective adaptation to stress and change in environment. These persons are exposed to a high risk of morbidity, mortality, dependence, longer hospital stay and institutionalization. The purpose of this screening is to improve management for these patients by proposing more specifically adapted care.

Conclusion: It is thus indispensable to screen for cognitive disorders systematically in patients aged over 75 years hospitalized in a surgery unit. The MMSE score can be used for this purpose. This work is in favour of a physician or better a geriatrician within the unit who could be financed directly by his-her own sector of activity.