title: A novel 3D-printed device for localization and extraction of trabeculae from human femoral heads: a comparison with traditional visual extraction.
abstract: In this study, we propose a novel method for accurate trabeculae extraction from human femoral heads using 3D-printing techniques and compare spatial deviation errors between this novel method and the conventional method. We found that spatial deviation errors, which indicate inaccuracy and unreliability, were significantly higher with the conventional method.
  
  
  BACKGROUND
  Assessment of structural and mechanical properties of local bone is important in the study of pathological changes associated with musculoskeletal degenerative diseases. However, the widely used visual extraction method (VIS) for trabecular columns showed large deviations from veridicality, referred to as spatial deviation errors (SDE). Here, we propose a novel method for accurately locating and trephining trabeculae using a 3D-printed (3DP) positioning device and also evaluate the SDE of the VIS.
  
  
  METHODS
  Twenty femoral heads were obtained from osteoporotic patients, and the trabecular columns were extracted from the principal compressive trabeculae by VIS (n = 10) or the 3DP (n = 10) method. Morphological, structural, and mechanical properties were compared between both groups along with the recorded errors in spatial deviation.
  
  
  RESULTS
  Compared with the 3DP group, the average angle of central axis deflection in the VIS group was significantly greater; SDE in the VIS group was 26.1, 8.8, 4.1, 9.8, 7.2, 8.1, and 10.1 % greater for bone mineral density, bone volume/tissue volume ratio, trabecular thickness, trabecular number, Young's modulus, yield strength, and ultimate strength.
  
  
  CONCLUSIONS
  In this study, a high degree of SDE was demonstrated in the VIS, which indicates that the conventional technique is unreliable. Additionally, accurate sample fabrication and credible quantitative analysis of local trabeculae among individuals can be achieved with the aid of computed tomography and the 3DP device, thus providing a more objective method for researching musculoskeletal degenerative diseases and possibly a better clinical understanding of these disorders.
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: H
authors.initials: H
authors.lastname: Lv
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: BNLMS State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: P
authors.initials: P
authors.lastname: Yin
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: X
authors.initials: X
authors.lastname: Su
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China.
authors.forename: P
authors.initials: P
authors.lastname: Yin
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China. zhanglihai301@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, General Hospital of Chinese PLA, No. 28 Fuxing Road, Beijing, 100853, China. pftang301@126.com.
authors.forename: P
authors.initials: P
authors.lastname: Tang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology; D004867:Equipment Design; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005270:Femur Head / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D066330:Printing, Three-Dimensional; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000295:instrumentation* / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: 3D printing; Bone sampling method; Heterogeneity; Spatial deviation error; Trabeculae