ObjectiveTo compare the effectiveness of percutaneous compression plate (PCCP) and hollow compression screw in the treatment of displaced femoral neck fractures. MethodsBetween January 2010 and June 2014, 70 patients with displaced femoral neck fractures were randomly divided into 2 groups. After reduction, fracture was fixed with PCCP in 35 cases (group A) and with hollow compression screw in 35 cases (group B). There was no significant difference in the gender, age, cause, side and type of fractures, time from injury to operation, associated disease, pre-operative Harris score and visual analogue scale (VAS) score between 2 groups (P > 0.05). The operation time, intra-operative blood loss, fracture healing time, fracture reduction quality, time of rehabilitation and weightloading; complication, post-operative Harris score and post-operative VAS score were compared between 2 groups. ResultsThe incisions healed by first intention. All patients were followed up 13-34 months (mean, 23.7 months). There were significant differences in operation time, intra-operative blood loss, and fracture healing time between 2 groups (P < 0.05). There was no significant in the fracture reduction quality between 2 groups (P > 0.05). Avascular necrosis of the femoral head occurred in 2 cases of group A after operation (fracture reduction quality: grade IV); and avascular necrosis of the femoral head occurred in 4 cases of group B after operation (fracture reduction quality: grade I in 2 cases, grade Ⅱ in 1 case, grade Ⅲ in 1 case, and grade IV in 1 case), nonunion in 1 case, and screw loosening in 3 cases; and there was significant difference in the incidence of bone nonunion and avascular necrosis of the femoral head between 2 groups (χ2=-3.997, P=0.046). Difference was significant in fracture reduction quality in the patients with avascular necrosis of the femoral head and nonunion between 2 groups (χ2=1.991, P=0.047). The time of rehabilitation and weight-loading of group A was significantly earlier than that of group B (P < 0.05); the Harris and VAS scores of group A were significantly better than those of group B at 12 months after operation (P < 0.05). ConclusionPCCP for treatment of displaced femoral neck fractures has better static stability and better sliding dynamic pressure effect than hollow compression screw, and it can provide earlier rehabilitation and weight-loading postoperatively and obviously decrease the incidence of bone nonunion and avascular necrosis of the femoral head, but avascular necrosis of the femoral head still occur in patients with poor reduction or comminuted fracture.