[Treatment aspects of interprosthetic femur fractures-retrospective analysis of 70 patients]. / Therapieaspekte interprothetischer Femurfrakturen ­ retrospektive Analyse von 70 Patienten.

BACKGROUND: Interprosthetic femur fractures (IFF) are rare injuries, whose surgical treatment is basically with osteosynthesis or revision arthroplasty. Various therapy algorithms have been proposed based on very small study collectives. Factors influencing the outcome are not known. OBJECTIVES: The aim of the retrospective monocentric study is to derive a treatment algorithm based on a large number of cases and to identify factors influencing the outcome. MATERIALS AND METHODS: Between 2006 and 2020, 70 IFF were identified. The surgical treatment comprised 38 osteosyntheses, 30 revision arthroplasties and 2 amputations. With classification and time to surgery, 69 perioperative variables were recorded. General and operative complications, as well as mortality, were determined in the follow-up period of 1 year. RESULTS: ASA and Charlson score correlated with 1­year-mortality. In addition, preoperatively increased CRP levels, reduced hemoglobin and the CHA2DS2-VASc score were identified as factors influencing mortality. Surgery within 24 h showed a trend towards fewer general complications. Transferred patients indicated an increased mortality. Based on classification according to Pires et al. or Füchtmeier et al. no clear treatment decision could be made. Relevant criteria for the surgical treatment were fracture localization, implant stability, bone vitality, anchoring possibility of the revision stem, as well as general condition of the patient. CONCLUSIONS: The identified factors influencing the outcome correspond to those of patients with hip fractures. IFF should be treated timely. A treatment path was developed on the basis of the largest patient group to date.