Correlation between hip osteoarthritis and proximal femoral fracture site: could it be protective for intracapsular neck fractures? A retrospective study on 320 cases

Summary: Proximal femoral fractures affect elderly people, showing high morbidity and mortality incidence resulting in a major economic burden on national healthcare systems. Understanding the causes of these injuries is of paramount importance to prevent the serious consequences of these fractures. Introduction: Hip osteoarthritis and proximal femoral fractures mainly affect elderly patients. Several authors, in their studies, tried to document a correlation between these conditions, but the results are conflicting. The aim of this study was to evaluate the relationship between hip osteoarthritis and the fracture site. Secondly, to evaluate if the grade of osteoarthritis could influence the fracture pattern. Methods: A retrospective study on 320 patients admitted for hip fracture between June 2015 and December 2016 was carried on. Radiographic images were evaluated, assessing the type of fracture, presence and grade of osteoarthritis according to Kellgren-Lawrence and Tönnis classifications, and their correlations. Results: Osteoarthritis was found to affect the fracture site showing a higher prevalence among subjects with extracapsular than those with intracapsular fractures (p < 0.00001). Patients with radiographic signs of arthritis had mainly trochanteric fracture. Conversely, patients without arthritis more frequently presented a femoral neck fracture. This correlation was even more significant as the severity of the OA increased. Conclusions: Results support the hypothesis that hip osteoarthritis could represent a protective factor for intracapsular fractures and a risk factor for trochanteric ones. The severity of arthritis is also associated with the fracture pattern.