Multicenter Study of Comorbidities in Patients with Periprosthetic Fractures After Total Hip Arthroplasty and Their Association with Immediate Postoperative Complications.

Background/Objectives: Periprosthetic fractures (PFs) can occur in both the upper and lower limbs, commonly resulting from falls at the same level. The frequency of PFs following total hip arthroplasty (THA) ranges from 0.045% to 4.1%, and this incidence is influenced by several factors, including age, gender, the type of prosthesis used, and existing comorbidities. Previous studies on this subject have been small in scale and did not adequately address the associated comorbidities, which pose a challenge for the aging population. This study aims to comparatively assess the incidence of THA-related PFs, immediate postoperative complications, and comorbidities in patients with PFs from three emergency hospitals. Methods: A retrospective observational study was conducted from 1 January to 31 December 2024, in which 54 patients with PFs hospitalized in three emergency hospitals (Bucharest, Oradea, and Ploiești) were evaluated, divided into Group B (n = 29), Group O (n = 14), and Group P (n = 11). Results: Of all patients with PFs, 81.48% had minor complications-grade 1, 9.26% had grade 2 complications (complications requiring medical treatment or other minor interventions), and 3.70% had complications requiring surgery or invasive procedures. Clavien-Dindo grade 5 (patient death) had an incidence of 3.70%. Cardiac pathology was the most common pathology; hypertension predominated in Group O (42.85%). Alzheimer's disease was associated in 7 patients (12.96%). Without associated pathology, about 13% of patients were identified. Diabetes mellitus also occurred frequently in 31.50%. Data analysis indicates a very weak positive correlation between the Dindo Index and the Charlson Comorbidity Index (r = 0.046), which is not statistically significant (p = 0.628). The effect size, measured by Fisher's z, is also reported as 0.046. Conclusions: No significant differences were found among the evaluated centers regarding therapeutic approaches, postoperative complications, and associated comorbidities. Furthermore, there is insufficient evidence to suggest a significant association between the Charlson Comorbidity Index and the Clavien-Dindo Index.