Analysis of the occurrence and influencing factors of early femoral head necrosis after internal fixation for femoral neck fractures in young adults

ZHAO Ze-peng; LIAO Long; SHI Bo; ZHANG Tao; YU Qing-long; XU Han; TANG Jin-yuan; ZHANG Yong-xi

doi:10.3969/j.issn.2095-252X.2025.09.006

Abstract：Objective To analyze the occurrence and related influencing factors of early osteonecrosis of the femoral head(ONFH)in patients aged under 50 years with femoral neck fractures after internal fixation surgery.Methods A retrospective analysis was performed on 109 young adult patients(≤50 years old)with femoral neck fractures admitted to Mianyang Central Hospital from January 2014 to September 2024.All patients underwent internal fixation surgery.Within one year after surgery,patients were divided into two groups based on the occurrence of femoral head necrosis:the ONFH group and the non-ONFH group.The incidence of ONFH was analyzed,and its influencing factors were explored.Results Univariate analysis showed that age,smoking status,fracture line location,time interval from fracture to surgery,reduction quality,and Garden classification were significantly different between the two groups(P<0.05).The Garden classification showed statistically significant associations with the occurrence of necrosis.The necrosis rate in stable types was 4.54%,significantly lower than that in unstable types(35.30%),indicating a reduced risk of necrosis,and the differences were statistically significant(P<0.01).Regarding fracture location,the necrosis rate in subcapital fractures was 42.50%,significantly higher than that in transcervical fractures(16.10%)and basicervical fractures(7.80%).These differences were also statistically significant(P<0.05),suggesting that subcapital fractures were a high-risk type for osteonecrosis.However,gender,body mass index(BMI),long-term alcohol consumption,hypertension,diabetes mellitus,removal of internal fixators,and reduction methods showed no statistically significant differences(P>0.05).Multivariate logistic regression analysis showed that age,smoking status,fracture line location,time from fracture to surgery,reduction quality,and Garden classification were statistically significant(P<0.05).Conclusions The incidence of ONFH after internal fixation is relatively high(22.93%)in the 109 patients,with 25 cases of ONFH(13 females and 12 males).Age,smoking status,fracture line location,time from fracture to surgery,reduction quality,and Garden classification are closely related to clinical outcomes.Medical professionals should pay close attention and implement targeted therapeutic measures in a timely manner to prevent or reduce the occurrence of postoperative ONFH,optimize treatment effects,and improve the quality of life.