The Journal of Hand Surgery (European Volume) 0E(0) 1–9 © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1753193412466764 jhs.sagepub.com JHS(E) Introduction The prehensile biomechanical function of the hand is largely due to the complex saddle-shaped thumb car- pometacarpal (CMC) or trapeziometacarpal (TM) joint, A three-dimensional analysis of osteoarthritic changes in the thumb carpometacarpal joint S. de Raedt Quantitative Imaging Group, Delft University of Technology, The Netherlands, Orthopaedic Research Unit, Regional Hospital Holstebro, Denmark and Orthopedic Research Department, Aarhus University Hospital, Denmark M. Stilling Orthopaedic Research Unit, Regional Hospital Holstebro, Denmark M. van de Giessen Quantitative Imaging Group, Delft University of Technology, Delft and Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands G. J. Streekstra Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands F. M. Vos Quantitative Imaging Group, Delft University of Technology, Delft and Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands T. B. Hansen Orthopaedic Research Unit, Regional Hospital Holstebro, Holstebro, Denmark Abstract The purpose of this study is to gain a better understanding of the changes due to osteoarthritis (OA) occurring in the thumb carpometacarpal (CMC) joint by comparing quantitative geometrical measurements in computed tomography scans of healthy and pathological joints in various stages of OA. The measurements were (1) the subluxation of the metacarpal on the trapezium, (2) distance from the scaphoid centre to the metacarpal base, and (3) distance from the metacarpal base to the articulating surface of the trapezium. The three-dimensional position of three characteristic points on the metacarpal, trapezium, and scaphoid were detected in each of the 90 wrists we scanned. The distances between the points were compared by statistical analysis. With high accuracy, we have been able to confirm and quantify that subluxation occurs in the dorso-radial direction. A significant difference in trapezium height and joint space width was found between the OA and control groups. The results indicate how to restore the centre of rotation in surgical treatment of OA with total joint arthroplasty, but the clinical relevance of these findings has to be tested in further clinical studies. Keywords Osteoarthritis, trapeziometacarpal joint, trapezium, carpal bones, CT Date received: 13th July 2011; revised: 10th October 2012; accepted: 14th October 2012 Corresponding author: Sepp de Raedt, Department of Orthopedics, Aarhus University Hospital, Tage-Hansens Gade 2, Building 10A, 8000 Aarhus C, Denmark Email: sepp.de.raedt@ki.au.dk 466764JHS 0 0 10.1177/1753193412466764Journal of Hand SurgeryRaedt et al. 2012 Full length article