Table 3 Classification system of Femoral neck fracture combined with anterior dislocation of femoral head

Type I

Pauwels angle <30°, and no dislocation of the femoral head

Type II

Pauwels angle is between 30°-50°, and no dislocation of the femoral head

Type III

Pauwels angle >50°, and no dislocation of the femoral head

TypeIV

Pauwels angle >50°, accompanied by anterior dislocation

a

anterior pubic dislocation

b

obturator subluxation

c

subpubic dislocation

TypeV

Pauwels angle>50°, accompanied by anterior dislocation

a

obturator dislocation of the femoral head

b

pelvic dislocation