title: Morphometric analysis of anatomical implant forms for minimally invasive acetabular fracture osteosynthesis.
abstract: BACKGROUND
  Anatomical implants enable minimally invasive osteosynthesis (MIO) and represent ideal complements of computer-assisted surgical workflows. This 3D morphometric study analyzes anatomical implant forms (AIF) for acetabular fracture osteosynthesis (AFO).
  
  
  METHODS
  Three-dimensional pelvis models were created from clinical CT data of 99 European-Caucasian patients (50 females, 49 males). The mean age of the patients was 60.1 years (range: 20-89; SD 10.8). Definition of a referential region of interest (ROI) corresponding to an AIF for AFO was followed by automated ROI computation for each of the 198 hemipelvises. Three-dimensional statistical modeling and analysis of the resulting 198 homologous ROIs consisted of thin-plate spline transformation, generalized Procrustes fit, and principal component analysis.
  
  
  RESULTS
  The mean ROI length was 18.2 cm (range: 16.1-20.1 cm; SD 0.76). The first principal component (PC1) mainly modeled the ROI length, which correlated well with body height (r = 0.325; p < 0.001). PC1 comprised 47.4% of the overall ROI form variation. PC2 primarily influenced the ROI curvature in the anterior-posterior (inlet) view. Curvatures were more pronounced in female patients compared to males (p < 0.001). There was no gender-specific ROI size variation. PC1-4 contained 80.2% of the total ROI form variation. Left and right ROI forms displayed symmetry.
  
  
  CONCLUSIONS
  This 3D morphometric study demonstrates the feasibility of anatomical implants for minimally invasive acetabular fracture osteosynthesis. Implant size/length is by far the most important variable of form variation. The necessity of gender-specific implant forms requires further investigation. The non-fractured, contralateral hemipelvis can be used for preoperative surgical planning. Ultimately, the plate design will depend on prospective implant fit tests based on the required fit as defined by the clinician.
authors: Department of Orthopaedic and Trauma Surgery, University Medical Center Freiburg, Freiburg, Germany. dirk.maier@uniklinik-freiburg.de
authors: Dirk
authors: D
authors: Maier
authors: Lukas
authors: L
authors: Kamer
authors: Hansrudi
authors: H
authors: Noser
authors: Zoran
authors: Z
authors: Stankovic
authors: Andreas
authors: A
authors: Guth
authors: Peter
authors: P
authors: Bäurle
authors: Norbert P
authors: NP
authors: Südkamp
authors: Wolfgang
authors: W
authors: Köstler
mesh_terms: D000077:Acetabulum / Q000293:injuries* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D050723:Fractures, Bone / Q000601:surgery*; D006621:Hip Joint / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D013223:Statistics as Topic; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D055815:Young Adult