Radiographic characteristics of femur nutrient artery in adult patients with developmental dysplasia of the hip

Objective To observe the characteristics of adult developmental dysplasia of the hip(DDH) patients' femur nutrient arteries by hip X-rays so as to avoid misdiagnosis of fracture. Methods A total of 163 patients(244 hips) in the Chinese PLA General Hospital with full-leg radiography and hip X-ray film were included from January 2016 to December 2018. There were 20 males and 143 females with an age of 20-69 (42±16.14) years old, Crowe type Ⅰ 72 hips, typeⅡ 58 hips, type Ⅲ 46 hips, and type Ⅳ 68 hips.The X-ray films with the femur nutrient artery were counted and measured. The arteries' direction and length (D), length of shaft (L), the angle between the vascular and the femoral anatomic line (α), the distance from the distally of artery to the apex of the greater trochanter (d) , ratio of the position entering the femoral shaft (R=d/L), were observed on the lateral x-ray film on the lateral radiograph. The correlation between D, R and α was analyzed. Results The visible percentage of femur nutrient arteries was 40.16% (98 in 244 hips). The D was 1.22-11.08(4.75±2.21)cm; the L was 38.83-46.88(42.52±1.90)cm. In the lateral X-rays, it ran from the posterior side to the front of the femur, the median of α was 8.20 °(5.58°, 12.79°); the d was 10.82-26.82(19.13±4.09)cm; the R was 0.26-0.60(0.45±0.09). A good correlation was found among D, R and α(r=0.673, rs=-0.690, rs=-0.680; all P values<0.01). Conclusions It is common to see the femur nutrient artery in hip X-ray film of DDH patients. Femur nutrient artery has its own characteristics, which could be provided to distinguish it from fracture. Key words: Hip dislocation; Developmental dysplasia of the hip; Femur nutrient artery; X-ray; Fracture