[Endoprosthetic treatment of pertrochanteric femoral fractures with concomitant coxarthrosis : A consecutive observational study with a control group].

Introduction: Hip replacement for pertrochanteric femoral fractures (PF) is challenging due to its complexity. Studies regarding this procedures are limited, therefore this monocentric study was conducted. The null hypothesis was no effect between replacement and internal fixation according to revision and mortality.

Material And Methods: Using an electronic database, patients who had received a hip replacement between 2007 and 2016 for a PF with a concomitant coxarthrosis were included in the study. The comparison group consisted of 1000 osteosyntheses for the treatment of PF. With the exception of coxarthrosis, the same inclusion and exclusion criteria were defined. Surgical revision and mortality with endpoint 2 years after the operation were the primary outcomes. At least 2 years postoperatively, a telephone follow-up was done with living patients who underwent replacement.

Results: Records of 90 hip replacements and 15 baseline characteristics were reviewed (e.g., age, sex, body mass index, preoperative blood values, ASA classification, dementia, fracture classification). Replacement was significantly associated with a delay to operation (p < 0.001), a longer duration of operation (p < 0.001), an increased blood loss (p < 0.001), more blood transfusions (p < 0.001), and a longer inpatient stay (p = 0.026). According to the primary outcome, the mortality rate (p = 0.002) and the rate of infection in a subgroup analysis (p = 0.031) were also significantly increased. Using Cox regression, replacement was associated with a significantly higher probability of a shorter survival rate (odds ratio: 1.438, confidence interval: 1.054-1.962). Therefore, the null hypothesis was rejected. At the follow-up 6.1 years postoperatively (3.2-8.6 years), only 17 patients with replacement (20%) were still alive. The mean Parker mobility score was 5.0 points (range 3-9 points).

Conclusion: In this study, a significantly higher rate of infection and mortality was observed in patients with hip replacement for a PF and with a concomitant coxarthrosis; compared to osteosynthesis of PF without coxarthrosis. Further studies are mandatory to provide the appropriate treatment for patients with this fracture pattern.