title: The impact of high total cholesterol and high low-density lipoprotein on avascular necrosis of the femoral head in low-energy femoral neck fractures.
abstract: BACKGROUND
  Avascular necrosis of the femoral head (AVNFH) typically constitutes 5 to 15% of all complications of low-energy femoral neck fractures, and due to an increasingly ageing population and a rising prevalence of femoral neck fractures, the number of patients who develop AVNFH is increasing. However, there is no consensus regarding the relationship between blood lipid abnormalities and postoperative AVNFH. The purpose of this retrospective study was to investigate the relationship between blood lipid abnormalities and AVNFH following the femoral neck fracture operation among an elderly population.
  
  
  METHODS
  A retrospective, comparative study was performed at our institution. Between June 2005 and November 2009, 653 elderly patients (653 hips) with low-energy femoral neck fractures underwent closed reduction and internal fixation with cancellous screws (Smith and Nephew, Memphis, Tennessee). Follow-up occurred at 1, 6, 12, 18, 24, 30, and 36 months after surgery. Logistic multi-factor regression analysis was used to assess the risk factors of AVNFH and to determine the effect of blood lipid levels on AVNFH development. Inclusion and exclusion criteria were predetermined to focus on isolated freshly closed femoral neck fractures in the elderly population. The primary outcome was the blood lipid levels. The secondary outcome was the logistic multi-factor regression analysis.
  
  
  RESULTS
  A total of 325 elderly patients with low-energy femoral neck fractures (AVNFH, n = 160; control, n = 165) were assessed. In the AVNFH group, the average TC, TG, LDL, and Apo-B values were 7.11 ± 3.16 mmol/L, 2.15 ± 0.89 mmol/L, 4.49 ± 1.38 mmol/L, and 79.69 ± 17.29 mg/dL, respectively; all of which were significantly higher than the values in the control group. Logistic multi-factor regression analysis showed that both TC and LDL were the independent factors influencing the postoperative AVNFH within femoral neck fractures.
  
  
  CONCLUSIONS
  This evidence indicates that AVNFH was significantly associated with blood lipid abnormalities in elderly patients with low-energy femoral neck fractures. The findings of this pilot trial justify a larger study to determine whether the result is more generally applicable to a broader population.
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Sun Yat-sen University, Huangpu East Road No. 183, Huangpu District, Guangzhou, 510700, Guangdong, China.
authors.forename: Xianshang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Sun Yat-sen University, Huangpu East Road No. 183, Huangpu District, Guangzhou, 510700, Guangdong, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhan
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Huangpu East Road No. 183, Huangpu District, Guangzhou, 510700, Guangdong, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Ultrasonography Department, The First Affiliated Hospital of Sun Yat-sen University, Huangpu East Road No. 183, Huangpu District, Guangzhou, 510700, Guangdong, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zeng
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Sun Yat-sen University, Huangpu East Road No. 183, Huangpu District, Guangzhou, 510700, Guangdong, China.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Yu
authors.affiliation: Department of Orthopaedics, Jinshan Hospital, Fudan University, Longhang Road No. 1508, Jinshan District, 201508, Shanghai, China. zhangxc666@aliyun.com.
authors.forename: Xinchao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Jinshan Hospital, Fudan University, Longhang Road No. 1508, Jinshan District, 201508, Shanghai, China.
authors.forename: Mingdong
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Zhongshan School of Medical, Sun Yat-sen University, Zhongshan second road 74th, Yuexiu District, Guangzhou City, 510080, Guangdong Province, China.
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Lai
authors.affiliation: Zhongshan School of Medical, Sun Yat-sen University, Zhongshan second road 74th, Yuexiu District, Guangzhou City, 510080, Guangdong Province, China.
authors.forename: Runzhen
authors.initials: R
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002784:Cholesterol / Q000097:blood*; D005260:Female; D005265:Femoral Neck Fractures / Q000097:blood* / Q000453:epidemiology / Q000601:surgery; D005271:Femur Head Necrosis / Q000097:blood* / Q000453:epidemiology / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000453:epidemiology / Q000601:surgery; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012189:Retrospective Studies
chemical_list: D008077:Lipoproteins, LDL; D002784:Cholesterol
keywords: Avascular necrosis of the femoral head; Femoral neck fracture; Harris Hip Score; Low-density lipoprotein; Total cholesterol