Sagar J Desai1, Simon Deluce2, James A Johnson3, Louis M Ferreira3, Alexandre E Leclerc4, George S Athwal5, Graham J W King6. 1. Department of Surgery, Western University, Roth | McFarlane Hand and Upper Limb Centre Bioengineering Laboratory, St. Joseph's Health Care, London, ON, Canada. 2. Schulich School of Medicine & Dentistry, Western University, Roth | McFarlane Hand and Upper Limb Centre Bioengineering Laboratory, St. Joseph's Health Care, London, ON, Canada. 3. Department of Surgery, Department of Mechanical and Materials Engineering, Western University, Roth | McFarlane Hand and Upper Limb Centre Bioengineering Laboratory, St. Joseph's Health Care, London, ON, Canada. 4. Department of Surgery, Centre Hospitalier Université Laval, Québec, PQ, Canada. 5. Department of Surgery, Western University, Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Health Care, London, ON, Canada. 6. Department of Surgery, Western University, Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Health Care, London, ON, Canada. Electronic address: gking@uwo.ca.
Abstract
BACKGROUND: The optimal articular shape for distal humeral hemiarthroplasty has not been defined because of a paucity of data quantifying the morphology of the normal distal humerus. This study defines the osseous anatomy and anatomic variability of the distal humerus using 3-dimensional imaging techniques. METHODS: Three-dimensional surface models were created from computed tomography scans obtained from 50 unpaired human cadaveric elbows. Geometric centers of the capitellum and the trochlear groove defined the anatomic flexion-extension axis. A coordinate system was created, and the distal humerus was sectioned into 100 slices along this axis. The C line was defined as the line of best fit connecting the geometric centers of each of the slices. RESULTS: The anatomic flexion-extension axis of the distal humerus was found to be an average of 1° ± 1° from the C line (range, 0°-3°) in the coronal plane and 2° ± 1° (range, 0°-7°) in the transverse plane. The average trochlear width was 22 ± 3 mm, and the average trochlear height was 18 ± 2 mm. The mean width of the capitellum was 17 ± 2 mm; the height was 23 ± 2 mm (P < .001). CONCLUSIONS: The difference in the capitellum width and height demonstrates that the capitellum is ellipsoid, not spherical. A data bank of humeral dimensions may be used for the development of future distal humeral hemiarthroplasty implants. A more anatomic implant may optimize kinematics and maximize contact area, thus minimizing contact stresses on the native ulna and radius.
BACKGROUND: The optimal articular shape for distal humeral hemiarthroplasty has not been defined because of a paucity of data quantifying the morphology of the normal distal humerus. This study defines the osseous anatomy and anatomic variability of the distal humerus using 3-dimensional imaging techniques. METHODS: Three-dimensional surface models were created from computed tomography scans obtained from 50 unpaired human cadaveric elbows. Geometric centers of the capitellum and the trochlear groove defined the anatomic flexion-extension axis. A coordinate system was created, and the distal humerus was sectioned into 100 slices along this axis. The C line was defined as the line of best fit connecting the geometric centers of each of the slices. RESULTS: The anatomic flexion-extension axis of the distal humerus was found to be an average of 1° ± 1° from the C line (range, 0°-3°) in the coronal plane and 2° ± 1° (range, 0°-7°) in the transverse plane. The average trochlear width was 22 ± 3 mm, and the average trochlear height was 18 ± 2 mm. The mean width of the capitellum was 17 ± 2 mm; the height was 23 ± 2 mm (P < .001). CONCLUSIONS: The difference in the capitellum width and height demonstrates that the capitellum is ellipsoid, not spherical. A data bank of humeral dimensions may be used for the development of future distal humeral hemiarthroplasty implants. A more anatomic implant may optimize kinematics and maximize contact area, thus minimizing contact stresses on the native ulna and radius.
Authors: Erica Kholinne; Rizki Fajar Zulkarnain; Arnold Adikrishna; Bin Zhu; Han Pyo Hong; In-Ho Jeon Journal: Biomed Res Int Date: 2017-10-18 Impact factor: 3.411