Intraoperative monitoring of femoral head perfusion in adult femoral neck fractures

Abstract

Objectives: To validate a novel intraoperative method of quantifying femoral head perfusion in adult patients with femoral neck fractures and to determine whether the lack of a perfusion waveform correlates with the development of osteonecrosis, nonunion, or reoperation. Design: Prospective cohort. Setting: Level 1 trauma center. Patients/Participants: Nineteen patients with 20 acute femoral neck fractures treated with hip-preserving surgical fixation. All patients underwent intraoperative quantification of femoral head perfusion. Intervention: Intraoperative quantification of femoral head perfusion pressure and waveform utilizing an intracranial pressure monitor. Main outcome measurements: Radiographic union, avascular necrosis, revision surgery. Results: Nineteen patients (8 male, 11 female, average age 56±21years) with 20 femoral neck fractures were enrolled. Eight fractures were stable (Garden 1-2/OTA B1.1-1.3) and 12 were unstable (Garden 3-4/OTAB2.1-3.3). A waveform was present in 12 of 20 cases. The average pressures were systolic 36.8mm Hg, diastolic 30.8mm Hg, pulse pressure 6.0mm Hg. A perfusion waveform was significantly associated with advanced age (P=0.02) and accompanied by trend toward stable fracture patterns. There were 4 deaths during the 1-year follow-up period (20%), and there were 5 conversions to total hip arthroplasty (25%). There was no significant association between revision surgery or death with the absence of a waveform. Conclusions: Our study demonstrated the feasibility of a relatively low cost, minimally invasive, technique to quantify femoral head perfusion. In our limited sample, the absence of perfusion did not correlate with our main outcomes; however, the trend toward correlation with increased fracture displacement was as expected. A larger cohort of patients will be needed to detect a significant difference between those with and without a perfusion waveform with regards to our primary outcomes. Further study is needed to delineate the role such data may play in medical decision making at the time of index surgery.