Intraoperative assessment of blood supply to the femoral head after femoral neck fracture / 中华创伤骨科杂志

ABSTRACT

Objective:To explore intraoperative assessment of blood supply to the femoral head after femoral neck fracture, and the correlation between the blood supply and postoperative osteonecrosis of the femoral head.Methods:A retrospective analysis was performed of the 63 patients with femoral neck fracture who had been treated at Department of Orthopaedic Trauma and Microsurgery, Zhongnan Hospital of Wuhan University by open reduction and internal fixation with hollow compression screws from April 2016 to March 2021. They were 39 males and 24 females with an age of (44.9±13.6) years. There were 42 cases of Garden type Ⅲ and 21 cases of Garden type Ⅳ. Time from injury to operation was (4.1±2.4) days. After internal fixation, a hole was drilled using a 2.0 mm Kirschner wire at 2.0 cm above the femoral head-neck junction to observe the velocity, color, and characteristics of the blood oozing at the drill hole. The patients were divided into a good oozing group of 51 cases in whom bright red blood oozing was observed within 15 seconds after drilling and a poor oozing group of 12 cases in whom dark red blood oozing was observed beyond 15 seconds after drilling. The incidence of postoperative femoral head necrosis, Harris hip score, and visual analogue scale (VAS) for pain were compared between the 2 groups. Single factor and multi factor analyses were conducted using the Cox regression model to analyze the factors influencing postoperative femoral head necrosis in the patients.Results:The 63 patients were followed up for 24 (18, 36) months. The 2 groups were comparable because there was no significant difference in the preoperative general data between them ( P>0.05). Femoral head necrosis was observed in 3 cases in the good oozing group and in 5 cases in the poor oozing group, showing a significant difference between the 2 groups ( P<0.05). The Harris hip score [90.0 (86.0, 92.0)] and the VAS pain score [1.0 (1.0, 2.0)] at 1 year after surgery in the good oozing group were significantly better than those in the poor oozing group [85.5 (71.3, 88.8) and 2.5 (1.0, 3.8)] ( P<0.05). Multivariate Cox regression analysis showed that Garden type Ⅳ ( HR=6.784, 95% CI 1.324 to 35.664, P=0.023) and intraoperative poor blood oozing ( HR=10.744, 95% CI 2.359 to 51.774, P=0.003) were risk factors for femoral head necrosis after cannulated compression screw fixation of fractures of displaced femoral neck ( P<0.05). Conclusions:The blood supply to the femoral head after femoral neck fracture can be directly assessed by drilling a hole in the femoral head after open reduction and internal fixation. Intraoperative poor blood oozing is a risk factor for the femoral head necrosis after cannulated compression screw fixation of fractures of displaced femoral neck.