title: Bone shape difference between control and osteochondral defect groups of the ankle joint.
abstract: The etiology of osteochondral defects (OCDs), for which the ankle (talocrural) joint is one of the common sites, is not yet fully understood. In this study, we hypothesized that bone shape plays a role in development of OCDs. Therefore, we quantitatively compared the morphology of the talus and the distal tibia between an OCD group and a control group.
  
  
  
  The shape variations of the talus and distal tibia were described separately by constructing two statistical shape models (SSMs) based on the segmentation of the bones from ankle computed tomography (CT) scans obtained from control (i.e., 35 CT scans) and OCD (i.e., 37 CT scans) groups. The first five modes of shape variation for the SSM corresponding to each bone were statistically compared between control and OCD groups using an analysis of variance (ANOVA) corrected with the Bonferroni for multiple comparisons.
  
  
  
  The first five modes of variation in the SSMs respectively represented 49% and 40% of the total variance of talus and tibia. Less than 5% of the variance per mode was described by the higher modes. Mode 5 of the talus (P = 0.004) primarily describing changes in the vertical neck angle and Mode 1 of the tibia (P < 0.0001) representing variations at the medial malleolus, showed statistically significant difference between the control and OCD groups.
  
  
  
  Shape differences exist between control and OCD groups. This indicates that a geometry modulated biomechanical behavior of the talocrural joint may be a risk factor for OCD.
authors: Department of Biomechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands. Electronic address: n.sarkalkan-1@tudelft.nl.
authors: N
authors: N
authors: Tümer
authors: Orthopaedic Research Center Amsterdam, Academic Medical Centre (AMC), Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. Electronic address: l.blankevoort@amc.uva.nl.
authors: L
authors: L
authors: Blankevoort
authors: Division of Image Processing, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands. Electronic address: M.van_de_Giessen@lumc.nl.
authors: M
authors: M
authors: van de Giessen
authors: Department of Radiology, Academic Medical Centre (AMC), Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. Electronic address: m.p.terra@amc.uva.nl.
authors: M P
authors: MP
authors: Terra
authors: Department of Radiology, UMC Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands. Electronic address: P.dejong-8@umcutrecht.nl.
authors: P A
authors: PA
authors: de Jong
authors: Department of Biomechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands; Department of Orthopedics, University Medical Centre Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands; Department of Rheumatology, University Medical Centre Utrecht, Heidelberglaan 100, Utrecht, 3584 CX, The Netherlands. Electronic address: h.h.weinans@tudelft.nl.
authors: H
authors: H
authors: Weinans
authors: Department of Biomechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands; Orthopaedic Research Center Amsterdam, Academic Medical Centre (AMC), Meibergdreef 9, Amsterdam, 1105 AZ, The Netherlands. Electronic address: g.j.m.tuijthof@tudelft.nl.
authors: G J M
authors: GJ
authors: Tuijthof
authors: Department of Biomechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands. Electronic address: a.a.zadpoor@tudelft.nl.
authors: A A
authors: AA
authors: Zadpoor
mesh_terms: D000843:Ankle Joint; D006801:Humans; D057072:Intra-Articular Fractures; D013628:Talus; D013977:Tibia; D014057:Tomography, X-Ray Computed
keywords: (Osteo)chondral defect; Ankle; Statistical shape model; Talocrural joint; Talus; Tibia