Postoperative periprosthetic fractures in patients with an Exeter stem due to a femoral neck fracture: cumulative incidence and surgical outcome

Purpose The purpose of this study is to report on the cumulative incidence and the outcome of surgically-treated postoperative PPFs in patients with femoral neck fractures treated with a THA or HA using an Exeter stem. Methods A consecutive series of patients operated during 1998-2010 due to a non-pathological femoral neck fracture using an Exeter stem were included in this cohort study. Patients were followed until 2012, or death, in order to obtain information about reoperations due to postoperative PPFs, and subsequent re-operations after surgery due to PPFs. In addition to local audit data the Swedish National Board of Health and Welfare's registry was used to identify patients who had been re-operated upon elsewhere in Sweden. ResultsA total of 2,757 patients (median age 82 years, 2,019 females) were identified and included in the study. Of these patients, 63 (2.3 %) sustained a postoperative PPF that was treated surgically. The majority of the Vancouver B1 (n = 21/23) and C (n = 14/14) fractures were treated using open reduction and internal fixation (ORIF), whereas most of the B2 (n = 16/25) fractures and the only B3 fracture were treated with stem revision. Three (4.8 %) patients were subsequently re-operated upon due to fracture-related complications, all B2 fractures, and were treated with ORIF (n = 2) or stem revision (n = 1). Conclusion The cumulative incidence of surgically treated PPFs was considerable among patients with Exeter stems operated due to a femoral neck fracture. The re-operation rate due to fracture-related complications was highest among patients with B2 fractures.