Mortality, functional outcomes and quality of life after hip fractures complicated by infection: a case control study.

Introduction: Infection is a detrimental complication of operatively treated hip fractures. The objective of this retrospective case-control study was to evaluate the mortality, the physical function and the quality of life of hip fractures complicated with infection and determine risk factors for deep infection in hip fractures. Patients and methods: All patients with hip fractures (31A and 31B OTA/AO) that were operatively managed over a 10-year period that subsequently developed deep infection were included in the study. Thirty-nine patients met the inclusion criteria. These patients were compared with a matched control group of 198 patients without infection. Minimum follow-up was 1 year. Mortality, Barthel index score, EQ-5D-5L, Parker mobility score and visual analogue scale (VAS) pain score were compared between groups. Results: Mortality at 1 month was 20.5 % and 43 % at 1 year. Half of the infections were acute and 28 % were polymicrobial. Mortality was greater in the infection group (43 % vs. 16.5 %, $p<0.0014$ ), and Barthel index was inferior in the infection group (14 vs. 18, $p<0.0017$ ) compared to control group. Logistic regression analysis revealed that time from admission to surgery was a negative factor that predisposed to infection. Conclusions: Patients complicated with infection after a hip fracture have higher mortality and inferior functional results. Delay from admission to surgery predisposes to infection.