Intraoperative monitoring of femoral head perfusion in adult femoral neck fractures

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 ± 21 years) 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 36.8 mm Hg, diastolic 30.8 mm Hg, pulse pressure 6.0 mm 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. LEVEL OF EVIDENCE: Prognostic Level II.