title: The epidemiological and clinical features of primary giant cell tumor around the knee: A report from the multicenter retrospective study in china.
abstract: OBJECTIVE
  We aimed to determine the demographic characteristics of giant cell tumor around the knee in China.
  
  
  METHODS
  Between March 2000 and June 2014, patients with primary giant cell tumor around the knee were recruited from 6 institutions located in different regions of China, and were reviewed retrospectively the clinical features according to gender and age.
  
  
  RESULTS
  334 qualified patients were included in this study. The sex ratio was 1.14:1 (178/156), with mean ages of 36.9 years in men and 33.1 years in women, constituting a significant difference (P=0.007). The prevalence of pathological fracture was 32.9% overall (28.7% in men and 37.8% in women). The prevalence of simple fracture was significantly higher in women (26.3%) than in men (15.2%), P=0.042. Tumor location and staging did not differ significantly according to sex (P>0.05). However, comparing with >40 years old, those patients aged ≤40 were more likely to have a right knee tumor (56.7% vs. 44.7%, P=0.042), less likely to have Enneking stage 3 disease (18.6% vs. 35.0%, P=0.005), and less likely to have both soft-tissue extension and a mass (18.6% vs. 34.0%, P=0.009).
  
  
  CONCLUSIONS
  Giant cell tumor around the knee was more common in men than in women, although female patients were younger on average. Further, cases among patients ≤40 years old were observed to be milder than cases among older patients. The results suggest that efficient treatment and preservation of function should both be valued for young patients with giant cell tumor around the knee.
authors.affiliation: Department of Traumatology, Tianjin Hospital, 406 Jiefang South Road, Tianjin 300210, PR China.
authors.forename: Fengsong
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Bone Tumor, Tianjin Hospital, 406 Jiefang South Road, Hexi District, Tianjin 300210, PR China.
authors.forename: Yongcheng
authors.initials: Y
authors.lastname: Hu
authors.affiliation: The Graduate School, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300071, PR China.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhao
authors.affiliation: The Graduate School, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300071, PR China.
authors.forename: Huilin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, The General Hospital of Jinan Military Commanding Region, 25 Shifan Road, Jinan, Shandong 250031, PR China.
authors.forename: Xiuchun
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Orthopedics, Xijing Hospital, Forth Military Medical University, No. 15 West Changle Road, Xincheng District, Xi'an, Shaanxi 710032, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Centre for Orthopaedic Research, Department of Orthopaedics, The Second Affiliated Hospital of Zhejiang University, School of Medicine, 88 Jiefang Road, Hangzhou 310008, PR China.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Department of Orthopredics, Jin Ling Hospital, 305 Zhong Shan East Road, Nanjing 210002, Jiangsu Province, PR China.
authors.forename: Sujia
authors.initials: S
authors.lastname: Wu
authors.affiliation: Orthopedics Department, Second Affiliated Hospital of Inner Mongolia Medical University, 1 Yingfang Road, Huimin District, Hohhot 010050, PR China.
authors.forename: Shibing
authors.initials: S
authors.lastname: Guo
authors.affiliation: Department of Oncology of Bone, The Third Hospital of Hebei Medical University, 139 Ziqiang Rd, Shijiazhuang 050051, PR China.
authors.forename: Guochuan
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology, Tianjin Neurological Institute, 154 Anshan Road, Heping District, Tianjin 300052, PR China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Wang
keywords: Clinical; Epidemiology; Giant cell tumor; Knee; Retrospective study